FIELD OF THE INVENTION

The present invention relates to a station and an associated process of accepting articles usable in the field of automatic systems for handling articles of various kinds. For example, the station and the process of the present invention can be used for handling - for the purpose of delivery and/or reclaim and/or loading - baggage and parcels in airports and similar facilities. In particular, the present invention can have application in the check- in areas of airports for handling baggage to be loaded onto aircraft.

BACKGROUND ART

As is well known, in the sector of passenger transport services there are presently in use check-in systems designed to carry out the procedure of registering the baggage of a passenger for the purpose of loading the baggage. With reference, for example, to airport facilities, check-in systems including a desk associated with a conveyor belt suitable for receiving and handling baggage are widespread today: the belt is connected to and controlled by a control station managed by an appointed operator.

During check-in operations, it is necessary for the user/passenger or the appointed operator to position the baggage in a loading area of the conveyor belt which is momentarily stationary; in this phase the conveyor belt is configured to enable the baggage resting upon it to be weighed. At the end of this phase, the appointed operator applies on the baggage an identification label (or tag) typically bearing an identification barcode; after this the conveyor belt is started by the operator and the baggage is then moved away from the loading area and directed towards subsequent checks before being loaded onto the aircraft.

Generally, in fact, these conveyor belts serve sorting lines that enable the baggage to be moved from the check-in area to an area for the loading thereof. The check-in systems just described can be defined as ones involving the direct assistance of an operator, since all the steps of registering users/passengers and their baggage are internally managed by an appointed operator. It should be noted, however, that the number of manual check-in systems active and made available to passengers by an airline company is limited in view of the operating costs, the number of check-in systems available in the airport and based on the number of appointed operators that the company can commit to manage such systems. These limitations sometimes prevent the flow of passengers in transit to be adequately handled: this condition causes the formation of queues that result in long, annoying waits for passengers. Moreover, the operating costs for airline companies are not negligible. In order to remedy this drawback, partially automatic check-in systems are becoming more widely used today, i.e. systems in which various steps of the baggage procedures for loading are left up to the passenger, or even completely automatic ones that can be totally managed by the user/passenger; in the latter case users can in fact carry out, in total autonomy, the registration of their baggage, send the latter off and receive a boarding pass.

A first example of an automatic check-in system is disclosed in patent application no. EP 0770546 A1. This system envisages the use of a conveyor belt configured to receive baggage, weigh it and finally send it off to a sorting line. The conveyor belt is controlled by a control unit entirely operated by the user. In order to prevent potential tampering with the baggage during and/or after the steps of weighing and checking the latter, the conveyor belt is enclosed within a closed environment having exclusively a front access door for the introduction of the baggage. Before starting the steps of weighing/checking the baggage, users must open the access door, position their baggage on the conveyor belt inside the enclosure and close the door. Only after closing the access door will the user be able to carry out the check-in operations required for loading. Inside the area of access there are sensors connected with the control unit, which is configured to weigh and measure the baggage: during the check-in operations the control unit verifies that the weight and the size of the baggage fall within the limits established by the airline company and/or the airport.

The automatic check-in systems described in patent application no. EP 0770546 A1 enable a passenger to carry out, in complete autonomy and safety, without any assistance from a human operator, the airport check-in procedure. At present, in fact, various airline companies provide for a certain number of manual check-in systems, tied to the number of available appointed operators, and a certain number of automatic check-in systems; in this manner the airline companies can guarantee an efficient service for passengers which serves to reduce the formation of annoying queues at check-in desks.

Although the automatic check-in systems described enable airport companies to provide a good, safe passenger and baggage registration service, the Applicant has found that such systems are not, however, free of drawbacks and can be improved from various standpoints. It should indeed be noted that the structure of such systems is complex: the setting up of a tamper-proof area of access suitable for containing the conveyor belt renders the entire check-in system cumbersome and very costly for airline companies. It should further be noted that the procedure the user must follow for the check-in operations is very complicated and awkward; in fact, in addition to having to position the baggage correctly inside the enclosure, the user must open and close the front access door correctly. A second example of an automatic check-in system is disclosed in patent application no. WO 2012/012841 A1. This system comprises a conveyor belt configured to receive baggage, weigh it and, finally, send it off to a sorting line. In view of the absence of any appointed staff during the check-in phase, the automatic check-in system comprises a security system which enables the detection of any intrusions/tampering with the baggage during the phase of checking the same. The security system comprises a physical front and lateral access barrier in the form of front and side walls (physical protections of the conveyor belt) extending from the conveyor belt and such as to enable the baggage to be placed exclusively from a single lateral zone of the belt itself.

The security system further comprises a plurality of sensors - defined by a predetermined number of photocells and two laser sensors - placed on the conveyor belt and managed by a controller. The controller is configured to manage a predetermined number of photocells and the movement of the conveyor belt in such a way that the baggage can be placed in a predetermined checking and weighing position on the belt itself: in this phase the controller is configured to establish whether the length of the baggage falls within a predetermined limit established by the airline company. Subsequently, the controller controls the photocells and laser sensors in such a way as to generate a side virtual flat surface and a top virtual flat surface, which, in cooperation with the front and side walls (physical barriers) of the conveyor belt, define a predetermined 6-sided box-shaped control volume placed around and totally enveloping the baggage. The check-in system, following the formation of the predetermined control volume, detects any interferences of foreign objects with the virtual surfaces and if appropriate defines an alarm condition which triggers the stop of the registration/weighing process. In greater detail, the controller is capable of verifying whether the baggage falls within the size limits in terms of width and height established by the airline company and detecting any intrusion by the user/third parties in the control volume during all the phases in which it is no longer envisaged that passengers can access their baggage. At the end of the checking steps, users can complete the registration of their baggage and send it off for loading.

As in the case of the systems described in patent application EP0770546A1 , the automatic check-in systems described in patent application WO2012/012841A1 enable a passenger to carry out the airport check-in procedure in complete autonomy and safety without any assistance from an appointed operator.

However, the systems described in patent application WO2012/012841A1 are an improvement over that of application EP0770546A1 ; the presence of virtual surfaces simplifies the step of positioning the baggage by the user, who will exclusively have to place the baggage on the conveyor belt. Although the systems described in the second example are an improvement over the ones described in the first example, the Applicant has found that the systems described in application WO2012/012841A1 , too, are not free of drawbacks and can be improved from various standpoints. It should be noted, in fact, that the baggage check procedure implemented by the sensors and the controller is not very flexible and sometimes makes the steps of registering the user and the baggage complex. Indeed, the presence or only the passage of an object, also of small dimensions, through a virtual plane generated by the sensors defines an alarm condition that results in the suspension of the baggage registration procedure. The checking system envisaged in patent application no. WO2012/012841A1 is not capable of ignoring accidental interferences with the virtual planes by objects and/or the user/passenger who is carrying out the check-in procedure alongside the conveyor belt; there will thus be numerous accidental interruptions of the procedure in which the controller detects false attempts by the passenger to tamper with the baggage. Moreover, the virtual box generated must have fixed dimensions exceeding those of the maximum baggage size acceptable by the system, providing for a margin of tolerance in order not to continuously generate alarms requiring repositioning in the case of baggage that is voluminous but within the norm. The virtual box is therefore and must necessarily be Oversized', increasing the risk of alarms due to accidental intrusions.

WO2015127503 discloses an automatic self-service baggage processing (check-in) station, in which the baggage is received by a conveyor belt and weighed. The controller of the station creates a virtual control volume to determine attempted intrusions toward the baggage during the check-in steps. In particular, the controller is also designed to modify the size of the control volume based on the size of the baggage received.

OBJECT OF THE INVENTION

The object of the present invention is thus substantially to overcome at least one of the drawbacks and/or limitations of the prior solutions.

A first objective of the invention is to provide an accepting station that enables an effective procedure of controlling an article to be carried out. In particular, it is an object of the present invention to provide an article accepting station that enables the article to be rapidly inspected and at the same time to provide a secure station enabling attempts to tamper with the article itself during the control procedure to be effectively detected.

It is also a principal object of the invention to limit, as much as possible, 'false' alarms, i.e. alarms due in the known systems to minimal intrusions that are wholly accidental.

It is a further objective to enable an adaptation of the control volume to the conditions in which the station operates, for example by taking into account a level of alert in the airport and/or a situation with a completely automatic check-in or, on the contrary, a check-in partially controlled by an operator It is also an object to be able to take into account variations in the scene around the control volume in order to be able to vary the size thereof, also dynamically.

It is a further object of the invention to provide an article accepting station that is structurally simple and compact and at the same time simple from a management and control standpoint.

It is a further objective of the invention to provide an accepting station that is in particular flexible in its application and can be easily integrated with presently known article conveyor systems without requiring any particular adaptations or modifications of the systems in use.

Moreover, it is an object of the invention to provide an accepting station that can be easily constructed.

One or more of the above-described objects, which will become more apparent in the course of the following description, are substantially achieved by an accepting station and a process of accepting articles in accordance with one or more of the accompanying claims.

SUMMARY

Aspects of the invention are described here below.

In a 1 st aspect there is provided a station (1) for accepting articles (P), in particular a check-in station for check-in areas of airports, comprising:

> at least one conveyor (2) longitudinally extending between a loading area (2a) and an unloading area (2b), said conveyor (2) being configured to receive at least one article (P) in the loading area (2a) and move it to the unloading area (2b) along an advancement direction (A),

> at least one weight detector (3) associated with the conveyor (2) and configured to emit at least one signal relative to the weight of the article (P) abutting on the conveyor (2),

> at least one control unit (4) active on the conveyor (2) and connected to the weight detector (3), said control unit (4) being configured to:

o determine, as a function of the signal received from the weight detector (3), a weight of the article (P) abutting on the conveyor (2),

o control the movement of the conveyor (2) to enable the article (P) abutting on the same conveyor (2) to be moved along the advancement direction (A).

In a 2nd aspect in accordance with the 1 st aspect, the control unit (4) is configured to receive a signal representative of a feature of the article (P) placed inside a predetermined inspection region, the control unit (4) being configured to define a control condition, wherein it: > generates a virtual control volume (V) placed at least partially around, or enveloping, the article (P), said virtual control volume (V) being calculated by the control unit (4) as a function of said signal,

> determines whether there is an intrusion condition in said control volume.

In a 3rd aspect in accordance with the preceding aspect, the signal representative of a feature of the article (P) is a signal representative of at least one among:

> a shape of the article (P) placed inside a predetermined inspection region,

> a dimension of the article (P) placed inside the predetermined inspection region,

> a position of the article (P) placed inside the predetermined inspection region.

In a 4th aspect in accordance with the 2nd or 3rd aspect, the accepting station (1) comprises at least one sensor (5, 6, 7), optionally a plurality of sensors (5, 6, 7) which, during the control condition, is configured to transmit said signal representative of at least one among:

> a shape of the article (P) placed inside a predetermined inspection region,

> a dimension of the article (P) placed inside the predetermined inspection region,

> a position of the article (P) placed inside the predetermined inspection region.

In a 5th aspect in accordance with any one of the aspects from the 2nd to the 4th, the control unit (4) determines, by means of said representative signal, at least one among a shape of the article (P), a dimension of the article (P), and a position of the article (P). In a 6th aspect in accordance with any one of the aspects from the 2nd to the 5th, the virtual control volume (V) is variable as a function of the article (P) placed inside the predetermined inspection region.

In a 7th aspect in accordance with any one of the aspects from the 2nd to the 6th, the virtual control volume (V) has dimensions and/or a geometry and/or a position calculated by the control unit (4) as a function of said signal.

In an 8th aspect in accordance with any one of the aspects from the 2nd to the 7th, the control unit (4), during the control condition, is configured to:

> receive said signal, in particular from at least one sensor (5, 6, 7) associated with the accepting station (1),

> as a function of said signal, determine at least one of the following parameters relating to the article (P) placed inside the inspection region:

o a cloud of points of the article (P),

o a cross-section of the article (P),

o an outline of the article (P),

o a shape of the article (P),

o a dimension of the article (P), o a position of the article (P) in relation to a reference, for example in relation to the conveyor (2),

> as a function of said parameter, generate said virtual control volume (V) placed at least partially around or enveloping the article (P).

In a 9th aspect in accordance with any one of the aspects from the 2nd to the 8th, the control unit (4), as a function of the signal received during the control condition, is configured to calculate at least one parameter of the virtual control volume (V), said parameter comprising at least one among:

> a shape of the virtual control volume (V),

> a maximum size of the virtual control volume (V), measured along the advancement direction (A),

> a maximum size of the virtual control volume (V), measured along a direction perpendicular to the advancement direction (A),

> a position of the virtual control volume (V) in relation to the position of the article (P) on the conveyor (2),

> a minimum distance between the virtual control volume (V) and article (P).

In a 10th aspect in accordance with any one of the aspects from the 2nd to the 9th comprising at least one sensor (5, 6, 7) configured to monitor a predetermined inspection region comprising at least the loading area (2a) of the conveyor suitable for receiving the article (P), and wherein the control unit (4), during a condition of monitoring the inspection region, and during a first time instant, is configured to:

> receive a signal from the sensor (5, 6, 7),

> as a function of said signal, generate a geometrical representation, in particular a two- dimensional one, of a body (C) placed inside the inspection region,

> as a function of said geometrical representation, calculate a first containing surface

(51) substantially enveloping said body (C) or a containing line (L1) substantially placed around said body (C),

and wherein the control unit (4), during the condition of monitoring the inspection region and during a second time instant following the first time instant, is configured to:

> receive a further signal from the sensor (5, 6, 7),

> as a function of said signal, generate a further geometrical representation, in particular a two-dimensional one, of a body (C) placed inside the inspection region,

> as a function of said geometrical representation, generate a second containing surface

(52) substantially enveloping said body (C), or a second containing line (L2) substantially placed around said body (C),

and wherein the control unit (4), during said monitoring condition, is configured to: > compare the value of a dimensional parameter of said first and said second containing surfaces (S1 , S2) or of said first and second containing lines (L1 , L2),

> following the comparison step, verify that the value of the dimensional parameter of the second surface has a variation in relation to the value of the dimensional parameter of the first surface below a predetermined threshold, or verify that the value of the dimensional parameter of the second containing line has a variation in relation to the value of the dimensional parameter of the first containing line below a predetermined threshold,

if such variation is within the predetermined threshold, the control unit (4) is configured to define the control condition, wherein it:

> receives at least one signal from the sensor (5, 6, 7), representative of at least one among:

o a shape of the article (P) placed inside a predetermined inspection region,

o a dimension of the article (P) placed inside the predetermined inspection region, o a position of the article (P) placed inside the predetermined inspection region,

> generates, as a function of said signal of the sensor (5, 6, 7), the virtual control volume (V) placed at least partially around or enveloping the article (P),

> determines whether there is an intrusion condition as a function of the signal received from the sensor (5, 6, 7) following the generation of the virtual control volume (V), if such variation is outside the predetermined threshold, the control unit (4) is configured to repeat the steps of the monitoring condition.

In an 11th aspect in accordance with the preceding aspect, the accepting station (1) comprises at least one sensor (5, 6, 7) configured to monitor a predetermined inspection region comprising at least the loading area (2a) of the conveyor suitable for receiving the article (P), and wherein the control unit (4), during the step of generating the geometrical representation of a body (C) placed inside the inspection region, is configured to:

> as a function of the signal received from the sensor (5, 6, 7), determine at least one of the following parameters in relation to the body (C) placed inside the identification region:

o a cloud of points of the body (C),

o a cross-section of the body (C),

o an outline of the body (C),

o a shape of the body (C),

o a dimension of the body (C),

> as a function of said parameter, generate a flat geometrical representation of the body, defined by one or more surfaces or by one or more closed outline shapes, > calculate the value of at least one dimensional parameter of said flat geometrical representation, said dimensional parameter comprising at least one among:

o a moment of inertia of the geometrical representation,

o an area of the geometrical representation,

o a perimetral extent of the geometrical representation,

as a function of the value of the dimensional parameter of said flat geometrical representation, calculate a surface enveloping said flat geometrical representation, or a line placed around said flat geometrical representation.

In a 12th aspect in accordance with the 10th or 1 1th aspect, the control unit (4) is configured to:

> verify a variation in the dimensional parameter of the second surface in relation to the parameter of the first surface,

> if such variation is a decrease in the dimensional parameter, repeat the steps of the monitoring condition,

> if such variation is an increase in the dimensional parameter, determine whether there is an intrusion condition in said control volume.

In a 13th aspect in accordance with any one of the aspects from the 2nd to the 12th, the control unit (4) is configured to generate a virtual control volume (V) spaced, in particular upwardly spaced, from the conveyor (2).

In a 14th aspect in accordance with any one of the aspects from the 2nd to the 13th, the virtual control volume (V) has a minimum distance (D) from an upper exposed surface of the conveyor (2), adapted to abuttingly receive the article (P), which is smaller than 100 mm, in particular comprised between 10 and 90 mm, still more in particular comprised between 20 and 60 mm.

In a 15th aspect in accordance with any one of the aspects from the 2nd to the 14th, the virtual control volume (V) comprises at least one lateral control volume (V2) configured to at least partially cover the article (P); the lateral volume (V2), along a cross-section perpendicular to the advancement direction (A), has a substantially "C" or "U" or "V" shape having a concavity facing an exposed surface of the conveyor adapted to abuttingly receive the article (P), in particular the lateral control volume (V2) defining a tunnel shape or an elongated one having a cross-section suggesting a "C" or "U" or "V" shape.

In a 16th aspect in accordance with the preceding aspect, the lateral volume (V2), according to a cross-section perpendicular to the advancement direction (A), has a cross- section delimited by an inner edge (8) and an outer edge (9) spaced from each other and defining the thickness of said lateral volume (V2).

In a 17th aspect in accordance with the preceding aspect, the first and second edges (8, 9) are placed at a minimum distance from each other comprised between 50 and 150 mm. In an 18th aspect in accordance with any one of the aspects from the 15th to the 17th, the lateral volume (V2) extends along the advancement direction (A) between a first and second end portions respectively facing the loading area (2a) and unloading area (2b) of the conveyor (2), said lateral volume defining a through cavity, extending between the first and second end portions, configured to contain the article (P) placed on the conveyor (2). In a 19th aspect in accordance with the preceding aspect, the virtual control volume (V) comprises a front volume (V1) placed in the first end portion of the lateral volume (V2), the front volume (V1) extending along a prevalent plane of extension and being configured to at least partially cover, according to a view along the advancement direction (A) of the article (P) on the conveyor (2), the front cross-section of the through cavity, in particular the front volume (V1) and lateral volume (V2) being distinct volumes.

In a 20th aspect in accordance with any one of the aspects from the 16th to the 19th, the control unit (4) is configured to calculate the distance between the inner edge (8) and the outer edge (9) of the lateral volume (V2).

In a 21 st aspect in accordance with the preceding aspect, the distance between the inner edge (8) and the outer edge (9) is variable along the extent of the cross-section.

In a 22nd aspect in accordance with any one of the aspects from the 4th to the 21st, the sensor (5, 6, 7) comprises at least one among:

> an image detecting camera, in particular an RGB-type camera,

> an RGB-D camera (or an RGB-Depth camera capable of simultaneously estimating a depth map and a 2D image, in particular a colour one);

> a 3D light field camera;

> an infrared camera, in particular a dual infrared depth sensor consisting of an infrared projector and in a camera sensitive to the same band,

> a laser camera, in particular a 3D laser scanner,

> a time-of-flight camera,

> a structured light optical measuring system,

> a plurality of photocells, for example configured to move toward and away from the article.

In a 23rd aspect in accordance with any one of the aspects from the 2nd to the 22nd, the control unit (4) is configured to generate the virtual control volume (V) in the loading area (2a) of the conveyor (2).

In a 24th aspect in accordance with any one of the preceding aspects, the control unit (4), during the control condition, is configured to:

> move a first article from the loading area to an intermediate area interposed between the loading area and the unloading area, > generate a virtual protection volume (VP) interposed between the first article and the loading area (2a),

> determine whether there is an intrusion condition in said virtual protection volume.

In a 25th aspect in accordance with the preceding aspect, the control unit (4), following the generation of the virtual protection volume (VP), is configured to receive a second article in the loading area (2a) and define said control condition; in particular the control unit (4), following the generation of the virtual protection volume (VP), is configured to:

> generate a virtual control volume (V) placed at least partially around, or enveloping, the second article (P), said virtual control volume (V) being calculated by the control unit (4) as a function of said representative signal,

> determine whether there is an intrusion condition in said virtual control volume (V) placed around, or enveloping, said second article.

In a 26th aspect in accordance with any one of the preceding aspects, the control unit (4), active on the conveyor (2) and connected to the weight detector (3), is configured to:

> selectively monitor the virtual control volume (V),

> detect intrusion conditions in the predetermined virtual control volume (V).

In a 27th aspect in accordance with any one of the preceding aspects, the accepting station (1) comprises at least one sensor (5) for monitoring a predetermined inspection region comprising at least the loading area (2a) of the conveyor suitable for receiving the article (P) and configured to transmit to the control unit (4) a signal representative of a scan of the inspection region, the control unit (4) being connected to the sensor (5) and, during said control condition, configured to:

> receive the signal from the sensor (5),

> as a function of said signal, determine:

o a dimensional parameter representative of a volume of a body (C) placed inside said virtual control volume (V);

o compare said dimensional parameter representative of the volume of the body (C) placed inside the virtual control volume (V) with a reference dimensional threshold; and

o determine an intrusion condition if said dimensional parameter is greater than the reference dimensional threshold.

In a 28th aspect in accordance with the preceding aspect, the control unit (4), if the value of the dimensional parameter of the body (C) is greater than the value of the reference dimensional threshold, is configured to determine an intrusion condition of the accepting station (1), and wherein the control unit (4), if the value of the dimensional parameter of the body (C) is less than the value of the reference dimensional threshold, is configured to proceed with the control condition. In a 29th aspect in accordance with any one of the aspects from the 26th to the 28th, the dimensional parameter of the body (C) comprises at least one among:

> a detected volume of the body (C), said detected volume being the only volume placed inside the virtual control volume (V),

> an area of the outer detected surface of the body (C), said outer detected surface being the only surface that is situated inside the virtual control volume (V),

> a calculated moment of inertia of the portion of the body (C) placed inside the virtual control volume (V),

> an area of the projection of the portion of the body (C) placed inside the virtual control volume (V) onto at least one virtual reference plane (X),

> an area of a cross-section of the portion of the body (C) placed inside the virtual control volume (V),

> a perimeter of the projection or cross-section of the portion of the body (C) placed inside the virtual control volume (V).

In a 30th aspect in accordance with any one of the aspects from the 26th to the 29th, the control unit (4) is configured to determine the intrusion condition if it:

> detects the presence of a body (C) intersecting an outer surface of the virtual control volume (V), and

> said dimensional parameter is greater than the reference dimensional threshold.

In a 31 st aspect in accordance with any one of the aspects from the 26th to the 30th, the control unit (4) is configured to:

> estimate a first projection of the portion of the body (C) placed inside the virtual control volume onto a first virtual reference plane (X),

> calculate a value of the dimensional parameter of said first projection (W), said dimensional parameter of said first projection comprising at least one among:

o an area of the first projection (W),

o a perimetral extent of the first projection (W),

o a moment of inertia of the first projection (W),

o a parameter proportional to the preceding ones or a combination of the same, > compare said value of the dimensional parameter of said first projection (W) with the value of a reference dimensional threshold,

and wherein the control unit (4) is configured to determine an intrusion condition if the value of the dimensional parameter of said first projection is greater than the value of the reference threshold.

In a 32nd aspect in accordance with the preceding aspect, the control unit (4) is configured to: > estimate a second projection (Z) of the portion of the body (C) placed inside the virtual control volume onto a second virtual reference plane (Y),

> calculate a value of a dimensional parameter of said second projection (Z), said dimensional parameter of said second projection comprising at least one among:

o an area of the second projection (Z),

o a perimetral extent of the second projection (Z),

o a moment of inertia of the second projection (Z),

o a parameter proportional to the preceding ones or a combination of the same,

> compare said value of the dimensional parameter of said second projection (Z) with the value of a reference dimensional threshold,

and wherein the control unit (4) is configured to determine an intrusion condition upon the occurrence of one of the following conditions, and in particular both of the following conditions:

> the value of the dimensional parameter of said first projection is greater than the value of the reference threshold,

> the value of the dimensional parameter of said second projection is greater than the value of the reference threshold.

In a 33rd aspect in accordance with any one of the preceding aspects, the control unit (4), during the control condition, is configured to:

> receive from the detector (3) a signal representative of the weight of the article (P) abutting on the conveyor (2),

> determine the weight of the article abutting on the conveyor (2),

> determine the substantial stability of the weight of the article abutting on the conveyor,

> in the event of stability of weight of the article on the conveyor (2), define said virtual control volume (V).

In a 34th aspect there is envisaged a process of accepting articles (P) comprising the following steps:

> positioning an article (P) on an loading area (2a) of a conveyor (2),

> detecting the weight of said article (P),

> following the weighing step, moving the article (P) on the conveyor (2) along an advancement direction (A).

In a 35th aspect in accordance with the preceding aspect, the process comprises a control step, wherein at least the following steps executed by a control unit (4) are provided for:

> obtaining, for example by means of a sensor (5, 6, 7), a signal representative of at least one among:

o a shape of the article (P) placed inside a predetermined inspection region,

o a dimension of the article (P) placed inside the predetermined inspection region, o a position of the article (P) placed inside the predetermined inspection region,

> generating a virtual control volume (V) placed at least partially around, or enveloping, the article (P), said virtual control volume (V) being calculated by the control unit (4) as a function of said signal,

> determining whether there is an intrusion condition in said control volume.

In a 36th aspect in accordance with the preceding aspect wherein, during the control step, the process comprises the following steps:

> as a function of the emitted signal, determining at least one of the following parameters parameters relating to the article (P) placed inside the identification region:

o a cloud of points of the article (P),

o a cross-section or outline of the article (P),

o a shape of the article (P),

o a dimension of the article (P),

o a position of the article (P) in relation to the conveyor (2),

> as a function of said parameter, generating the virtual control volume (V) placed at least partially around or enveloping the article (P).

In a 37th aspect in accordance with the 35th or 36th aspect, the process comprises, during the control step, at least one step of calculating at least one parameter of the virtual control volume (V) as a function of the emitted signal, said parameter comprising at least one among:

> a shape of the virtual control volume (V),

> a maximum size of the virtual control volume (V), measured along the advancement direction (A),

> a maximum size of the virtual control volume (V), measured along a direction perpendicular to the advancement direction (A),

> a position of the virtual control volume (V) in relation to the position of the article (P) on the conveyor (2),

> a minimum distance between the virtual control volume (V) and article (P).

In a 38th aspect in accordance with any one of the aspects from the 35th to the 37th, the process comprises at least one monitoring step preceding the control step, said monitoring step, during a first time instant, comprising at least the following substeps:

> emitting, for example by means of the sensor (5, 6, 7), a signal representative of an inspection region located in the loading area (2a) of the conveyor (2),

> as a function of said signal, generating a geometrical representation, in particular a two-dimensional one, of a body (C) placed inside the inspection region, > as a function of said geometrical representation, generating a first containing surface (S1) placed around or enveloping said body (C), or a first containing line (L1) substantially placed around said body (C),

the process, during the monitoring step of the inspection region and during a second time instant following the first time instant, comprising the following substeps:

> emitting, for example by means of the sensor (5), a signal representative of an inspection region located in the loading area (2a) of the conveyor (2),

> as a function of said signal, generating a geometrical representation, in particular a two-dimensional one, of a body (C) placed inside the inspection region,

> as a function of said geometrical representation, generating a second containing surface (S2) placed around or enveloping said body (C), or a second containing line (L2) substantially placed around said body (C),

the process, during said monitoring condition, comprises the following substeps:

> comparing the value of a dimensional parameter of said first and said second containing surfaces (S1 , S2) or of said first and second containing lines (L1 , L2),

> following the comparison step, verifying that the value of the dimensional parameter of the second surface has a variation in relation to the value of the dimensional parameter of the first surface below a predetermined threshold, or verifying that the value of the dimensional parameter of the second containing line has a variation in relation to the value of the dimensional parameter of the first containing line below a predetermined threshold,

if such variation is within the predetermined threshold, defining the control step wherein, as a function of a signal emitted by the the sensor (5), the virtual control volume (V) placed at least partially around or enveloping the article (P) is generated,

if such variation is outside the predetermined threshold, the process envisages repeating the substeps provided for during the monitoring step.

In a 39th aspect in accordance with the preceding aspect, the step of generating the geometrical representation of the body (C) placed inside the inspection region, comprises the following substeps:

> estimating at least one of the following parameters relating to the body (C) placed inside the identification region:

o a cloud of points of the body (C),

o a cross-section or outline of the body (C),

o a shape of the body (C),

o a dimension of the body (C),

> as a function of said estimate, generating a flat geometrical representation of the body defined by one or more surfaces or by one or more closed outline shapes, > calculating the value of at least one dimensional parameter of said flat geometrical representation, said dimensional parameter comprising at least one among:

o a moment of inertia of the geometrical representation,

o the area of the geometrical representation,

o the perimetral extent of the geometrical representation,

as a function of the value of the dimensional parameter of said flat geometrical representation, generating a surface placed around or enveloping said flat geometrical representation.

In a 40th aspect in accordance with the 38th or 39th aspect, the dimensional parameter of the first and second surface comprises at least one among:

> a moment of inertia of the geometrical representation,

> the area of the geometrical representation,

> the perimetral extent of the geometrical representation.

In a 41st aspect in accordance with any one of the aspects from the 35th to the 40th aspect, the process comprises the following steps:

> during the control step, estimating the weight of the article abutting on the conveyor,

> during the control step, verifying that the size of the article (P) abutting on the baggage falls within a predetermined threshold,

> during the control step, monitoring the virtual control volume in such a way as to detect any interferences,

> following the control step, moving the article (P) on the conveyor (2) from the loading area (2a) to an unloading area (2b).

In a 42nd aspect in accordance with the preceding aspect, the process comprises an intrusion condition determined by the detection of one or more bodies intersecting the virtual control volume (V).

In a 43rd aspect in accordance with any one of the aspects from the 34th to the 42nd, the process comprises a control step wherein there are envisaged at least the following substeps:

> generating a virtual control volume (V) placed at least partially around or enveloping the article (P),

> monitoring, for example by means of a sensor (5, 6, 7), an inspection region in which is the article (P) is accommodated,

> receiving a signal representative of the inspection region, for example transmitted by said sensor (5),

> as a function of said signal and by means of a control unit (4):

o determining a dimensional parameter representative of a volume of a body (C) placed inside said virtual control volume (V); o comparing said dimensional parameter representative of the volume of the body (C) placed inside the virtual control volume (V) with a reference dimensional threshold; and

o determining an intrusion condition if said dimensional parameter is greater than the reference dimensional threshold.

In a 44th aspect in accordance with the preceding aspect, wherein, if the value of the dimensional parameter of the body (C) is greater than the value of the reference dimensional threshold, an intrusion condition will be determined,

and wherein, if the value of the dimensional parameter of the body (C) is less than the value of the reference dimensional threshold, the control condition will continue.

In a 45th aspect in accordance with the preceding aspect, the dimensional parameter of the body (C) comprises at least one among:

> a detected volume of the body (C), said detected volume being the only volume placed inside the virtual control volume (V),

> an area of the outer detected surface of the body (C), said outer detected surface being the only surface that is situated inside the virtual control volume (V),

> a calculated moment of inertia of the portion of the body (C) placed inside the virtual control volume (V),

> an area of the projection of the portion of the body (C) placed inside the virtual control volume (V) onto at least one virtual reference plane (X),

> an area of a cross-section of the portion of the body (C) placed inside the virtual control volume (V),

> a perimeter of the projection or of the cross-section of the portion of the body (C) placed inside the virtual control volume (V).

In a 46th aspect in accordance with any one of the aspects from the 43rd to the 45th, the step of determining the intrusion condition comprises:

> detecting the presence of a body (C) intersecting an outer surface of the virtual control volume (V), and

> determining whether said dimensional parameter is greater than the reference dimensional threshold.

In a 47th aspect in accordance with any one of the aspects from the 43rd to the 46th, further comprising at least the following substeps:

> estimating a first projection of the body (C) placed inside the virtual control volume onto a first virtual reference plane (X),

> calculating a value of a dimensional parameter of said first projection (W), said dimensional parameter of said first projection comprising at least one among:

o an area of the first projection (W), o a perimetral extent of the first projection (W),

o a moment of inertia of the first projection (W),

o a parameter proportional to the preceding ones or a combination of the same,

> comparing said value of the dimensional parameter of said first projection (W) with the value of a reference dimensional threshold,

> optionally estimating a second projection (Z) of the body (C) placed inside the virtual control volume onto a second virtual reference plane (Y),

> optionally calculating a value of a dimensional parameter of said second projection (Z), said dimensional parameter of said second projection comprising at least one among: o an area of the second projection (Z),

o a perimetral extent of the second projection (Z),

o a moment of inertia of the second projection (Z),

> optionally comparing said value of the dimensional parameter of said second projection (Z) with the value of a reference dimensional threshold,

the verification step further comprises the following substeps:

> determining an intrusion condition upon the occurrence of at least one of the following conditions:

o the value of the dimensional parameter of said first projection is greater than the value of the reference threshold,

o the value of the dimensional parameter of said second projection is greater than the value of the reference threshold.

In a 48th aspect in accordance with any one of the preceding aspects, the control unit (4) is configured to receive at least one additional parameter characterizing at least one body (C) present in the inspection region and/or said inspection region (R) and/or said accepting station (1), and to calculate the virtual control volume (V) also as a function of said additional characterizing parameter.

In a 49th aspect in accordance with any one of the preceding aspects, as a function of the monitoring signal, the control unit is configured to detect a variation inside the inspection region (R), said variation being caused by a presence and/or movement of the body inside the inspection region (R).

In a 50th aspect in accordance with the preceding aspect, the control unit determines a variation in the virtual control volume tied to said variation detected inside the inspection region (R), said variation being a function of at least one position parameter of said body (C), and/or at least the additional parameter characterizing said body and/or said inspection region (R) and/or said accepting station (1).

In a 51 st aspect in accordance with the preceding aspect, the position parameter of said body comprises at least one among: > an absolute position (s) of said body (C) in the inspection region (R),

> an assumed relative position (t) of said body (C) in relation to the other bodies in the inspection region (R),

> an assumed relative position (t) of said body (C) in relation to the article (P) placed in the loading area (2a),

> an assumed relative position (t) of said body (C) in relation to a reference placed in the inspection region (R).

In a 52nd aspect in accordance with any one of the preceding aspects, the additional parameter characterizing said body (C) comprises at least one selected in the group among:

> a modulus (u) of an absolute velocity (v) of said body (C);

> a direction (w) of the absolute velocity (v) of said body (C);

> a sense (x) of the absolute velocity (v) of said body (C);

> a path of movement (y) of said body (C);

> a modulus (u) of a relative velocity (v) of said body (C) in relation to the article (P);

> a direction (w) of the relative velocity (v) of said body (C) in relation to the article (P);

> a sense (x) of the relative velocity (v) of said body (C) in relation to the article (P);

> a path of movement (y) of said body (C) in relation to the article (P) or to a path of movement of said article (P);

> a profile of said body (C);

> a part of the profile of said body (C);

> a parameter that is a function of the profile of said body (C);

> a dimension of said body (C).

In a 53rd aspect in accordance with any one of the preceding aspects, the additional parameter characterizing said inspection region (R) comprises at least one selected in the group among:

> an alert condition in the place where the accepting station (1) is located;

> a security level assigned to the inspection region, for example high, medium or low security;

and wherein the additional parameter characterizing the accepting station (1) is representative of at least one selected in the group among the following conditions:

> an operating condition of the accepting station,

> a condition of supervision by a dedicated operator,

> a condition of an operator's presence for the supervision of a plurality of stations,

> an unsupervised working condition of the station,

> a condition of the machine cycle of the station, > a condition in which several passengers are present in proximity to the station,

> an alert condition signalled by the airport,

> a system sensitivity request advanced by the airport.

In a 53rd aspect in accordance with any one of the preceding aspects, the control unit is configured to modify the dimensions of the virtual control volume over time as a function of a variation detected inside the inspection region (R), said variation being caused by a presence and/or movement of a body inside the inspection region (R).

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments and some aspects of the invention will be described below with reference to the accompanying drawings, provided solely by way of illustration and hence not by way of limitation, in which:

> Figure 1 is a schematic perspective view of a first embodiment of an accepting station in accordance with the present invention;

> Figure 2 is a schematic perspective view of a second embodiment of an accepting station in accordance with the present invention;

> Figures 3 and 4 illustrate respective control conditions of the accepting station of figure 2;

> Figure 5 is a view from above of the accepting station in the control condition of figure 4;

> Figure 6 is a side view of the accepting station in the control condition of figure 4;

> Figure 7 is a sectional view, according to the line VII-VII, of the accepting station of figure 5;

> Figures 8 and 9 are further schematic views of an accepting station in accordance with the present invention;

> Figures 10 and 11 are schematic perspective views of further control conditions of the accepting station of figure 2;

> Figure 12 is a schematic perspective view of a third embodiment of an accepting station in accordance with the present invention;

> Figure 13 illustrates an operating condition of the accepting station of figure 12;

> Figures 14 to 18 schematically illustrate some steps of detecting an article placed on the accepting station in accordance with the present invention;

> Figure 19 schematically illustrates an intrusion attempt by a user in a control volume of the accepting station in accordance with the present invention;

> Figure 20 is a sectional view of the control volume of figure 19;

> Figures 21 and 22 schematically illustrate control steps of the accepting station in accordance with the present invention; > Figures 23 and 24 schematically illustrate a variant embodiment of the control volume of the accepting station in accordance with the present invention.

DEFINITIONS AND MATERIALS

The figures may illustrate the object of the invention by means of representations that are not scale drawings; therefore, parts and components illustrated in the figures in relation to the object of the invention may exclusively regard schematic representations.

The term article P may be understood to mean a bag, a suitcase, a package, a load or an element having a similar structure and function. The article can thus be made of any type of material. For example, if the article is defined by a bag or suitcase, the same can be made at least partially from one or more of the following materials: plastic, metal, fabric and nonwoven fabric.

The term body C may be understood to mean at least one, and also a combination of:

> at least one article P,

> one or more objects of any nature, shape and size,

> one or more portions of an individual, for example of a user of the accepting station or an operator overseeing the operation of the accepting station.

The term control unit may be understood to mean one or more components of a central processing unit (CPU) which are configured to coordinate all the actions necessary for executing an instruction and sets of instructions. The control unit can comprise one or more digital units, for example of the microprocessr type, or one or more analogue units, or an appropriate combination of digital and analogue units.

The term virtual control volume means a volume of space that is subjected to a data analysis by the control unit according to the described routines; the analysis of this volume is based on data received from one or more sensors capable of detecting the presence and spatial positioning of bodies inside the control volume. The control volume cannot be distinguished by the user from the surrounding space and is defined by the control unit using specific mathematic algorithms.

DETAILED DESCRIPTION

Accepting station

The number 1 denotes in its entirety an accepting station usable, for example, in the field of automatic systems for handling articles of various kinds. For example, the accepting station 1 can be used for handling - for the purpose of delivery and/or reclaim and/or loading - baggage and parcels in airports and similar facilities; in particular, the accepting station 1 can be advantageously employed in the check-in areas of airports for handling baggage to be loaded onto aircraft. In particular, reference will be made hereinafter to a check-in station for airports serving the purpose of accepting and picking up the baggage before it undergoes further security checks and is loaded onto the aircraft. The accompanying figures illustrate a preferential, but non-limiting configuration of the invention, in which the accepting station 1 is used to load the baggage and weigh, check and move the same on the sorting lines 12. In any case, the accepting station 1 of the present invention can also have application in the industrial realm, where it can be used for handling and/or sorting products of any nature, or also in any other sector that requires specific conditions for picking up articles (for example for the purposes of postal dispatch). The accepting station 1 comprises a conveyor 2 longitudinally extending between a loading area 2a and an unloading area 2b; the conveyor 2 is configured to receive at least one article P in the loading area 2a and move it to the unloading area 2b along an advancement direction A. In general the conveyor is a system for automatically removing the article P from the area for weighing the article itself; in the broadest sense thereof, the conveyor could be a trapdoor, an inclined surface or a pusher. The conveyor 2 could in fact work with negative angles (a surface inclinable on command, or a trapdoor openable on command, where both exploit gravity to move the article) and in all cases the intrusion monitoring procedures described below could be equivalently applied. In greater detail, the conveyor 2 has an exposed surface 13 configured so as to define an operative section which represents the portion of the conveyor 2 directly intended to abuttingly receive the article P and move it along the direction A. In the configuration illustrated in the accompanying figures (solely by way of example), the operative section extends along a rectilinear direction. In the accompanying figures a preferred, but non-limiting, configuration of the invention is illustrated, wherein the operative section, under conditions of use, has a slight inclination relative to the ground starting from the loading area 2a and up to the area for unloading the article P; in particular, the operative section has an inclination relative to the ground of less than 30°, in particular comprised between 3° and 10°. The possibility of constructing a conveyor 2 having an operative section which, under conditions of use of the station 1 , extends along a rectilinear and horizontal direction is not ruled out. The conveyor 2 can comprise: at least one conveyor belt; a belt portion carrying a plurality of rollers freely moving in rotation about an axis thereof and which are suitably positioned in respective cavities of the belt itself; a system with transverse rollers. The accompanying figures illustrate a preferred, but non-limiting, embodiment of the invention wherein the conveyor 2 comprises at least one conveyor belt comprising essentially an endless belt wrapped around one or more terminal rollers, at least one of which is motorized. In particular, the movement of the conveyor belt is driven by means of an activation device, for example a motor, which can be directly connected to the belt and drive the movement of the same, for example thanks to one or more frictional wheels. Alternatively, the device can be associated with one or more rollers (idlers or also a tensioning roller) in such a way as to motorize the latter. By virtue of the friction between the rollers and the belt it is possible to set the latter in motion and proceed to move the article P. In a first configuration, the conveyor 2 comprises a single conveyor belt extending from the loading area 2a to the unloading area 2b. In a second configuration illustrated in the accompanying figures, the conveyor 2 comprises a plurality of two or more conveyor belts placed in succession and aligned with one another along the advancement direction A. Each conveyor belt is independently motorized: one conveyor belt comprises an electric motor which works independently of the electric motor of another conveyor belt.

The accompanying figures illustrate a preferred configuration of the invention, wherein the conveyor 2 comprises three conveyor belts. The first conveyor belt 2 substantially defines the area for loading the article P. The second conveyor belt is placed immediately after the first conveyor belt in relation to the advancement direction A: the second conveyor belt is movable independently of the first conveyor belt and is configured to define an intermediate rest area for the article P. The third conveyor belt is placed immediately after the second conveyor belt in relation to the advancement direction A (the second conveyor belt is interposed between the first and third belts): the third conveyor belt is movable independently of the first and second conveyor belts and is configured to define the area for unloading the article for the purpose of the subsequent sorting thereof. The third conveyor belt can be placed in the sorting line 12: the third belt is configured to unload the article - moving on the conveyor 2 - onto the sorting line 12. With respect to materials, the conveyor belt is advantageously made at least partially of rubber so as to ensure optimal friction between the article, for example an item of baggage, and the exposed surface of the belt same. In a preferred embodiment of the invention, the accepting station 1 comprises a control unit 4 connected with the conveyor 2 (see the dashed connection line "a" of data/command transmission/reception between the control unit 4 and the conveyor 2 shown in figures 1 , 2 and 4) and which is configured to control the movement of the same. In particular, the control unit 4 is connected to the activation device (for example the electric motor) and is configured to control the latter for the purpose of managing the movement of the conveyor 2. As described above, in a preferred, but non- limiting configuration of the invention, the conveyor 2 comprises three conveyor belts; in this configuration, the control unit 4 is connected with each belt and is configured to control the movement of the belts themselves independently of one another. For example, in a predetermined condition of the accepting station 1 , the control unit 4 is configured - by means of the activation device - to control the movement of the third belt to enable an article to be unloaded onto the sorting line 12 whilst the same control unit 4 brings (simultaneously) the first and/or second belt to a stop. In one variant, the control unit 4 is configured to control the movement of the first belt and second conveyor belt and, simultaneously, bring the third belt to a stop. In a further variant, the control unit 4 is configured to control the movement of the second and third belt and, simultaneously, bring the first belt to a stop. Figure 1 illustrates a configuration of the accepting station 1 comprising a single conveyor 2; in a further embodiment of the accepting station 1 , the same can comprise two (figure 2) or more conveyors 2 placed substantially side by side along a transversal alignment direction, in particular perpendicular to the direction A. As can be seen from the accompanying figures, the accepting station 1 can comprise a tunnel 14 placed on the conveyor 2 and configured to at least partially cover said conveyor 2. In greater detail, the tunnel 14 is configured to cover at least the unloading area 2b of the conveyor 2: the tunnel does not cover the loading area 2a, which must be accessible for positioning the article P on the conveyor 2. The tunnel 14 has an entrance port 15 for the entry of the articles P into the tunnel 14: the entrance port 15 is situated above and around the conveyor 2 and is turned towards the loading area 2a of the conveyor 2. In a configuration illustrated in the accompanying figures, the tunnel 14 extends from the second conveyor belt to the end of the third conveyor belt and hence to the sorting line 12. The tunnel 14 is configured to define a cover (barrier) of the conveyor 2 suitable for preventing access to the sorting areas and to any articles P in transit. The accepting station 1 comprises at least one weight detector 3 associated with the conveyor 2 and configured to emit at least one signal relating to the weight of the article P abutting on the conveyor 2 (see for example figure 6). In particular, the detector 3 is associated with the operative section of the conveyor 2 in the area 2a for loading the article P. From a structural standpoint, the weight detector 3 can comprise a scale, for example a torsion, hydraulic or pneumatic scale. In general, if the station is a check-in station of an airport, the weight detector 3 will be of a type certified for weighing baggage destined to be loaded onto aircraft. As described above in a preferred embodiment of the invention, the accepting station 1 comprises the control unit 4. The unit 4 is advantageously connected to the weight detector 3 (see the connection line "f in figure 6) and configured to determine, as a function of the signal received from the weight detector 3, the weight of the article P abutting on the conveyor 2, in particular abutting on the loading area 2a of the conveyor belt, optionally of the first conveyor belt. The control unit 4, in a predetermined control condition, can verify whether the weight of the article abutting on the conveyor complies with a certain limit. For example, during the control condition, the control unit 4 can be configured to: receive a signal from the weight detector 3, determine a stability of the weight signal received from the detector, determine, as a function of said stable signal, the weight of the article P abutting on the loading area 2a of the conveyor 2, and compare the value of the weight detected with the value of a predetermined maximum threshold. If the control unit 4 determines that the weight of the article P is below the predetermined maximum threshold, the same unit 4 is configured to define a condition of approval of the article P, in relation to the weight: in this condition the control unit 4 establishes that the article P abutting on the conveyor 2 has a weight which falls within the required parameters. The control unit 4, in the condition of approval of the article P, can control the conveyor 2 so as to move the article P along the advancement direction A, weighed for the sending thereof to the unloading area 2b. If the control unit 4 determines that the weight of the article P is greater than the predetermined maximum weight threshold, the same unit 4 is configured to define a stop condition during which it prevents the movement of the conveyor 2; in the latter condition, the unit 4 prevents the articles P which exceed the allowed weight from being sent off. In general it will be established whether the weight of the baggage exceeds the maximum allowed limits and can thus not be loaded, or whether, by contrast, despite the weight being over the limit, it can in any case be loaded after the defined procedures for bulky baggage have been followed (for example following the payment of an extra shipping charge). As can be seen from the accompanying figures, the accepting station 1 advantageously comprises at least one check-in desk or counter 10 positioned alongside the conveyor 2 in the area 2a for loading the article P. The check- in counter 10 is configured to define a sort of user control panel serving to carry out predetermined operations of checking the article to enable the registration and consequently the sending thereof to the sorting line 12. In greater detail, the accepting station 1 comprises a counter 10 for each conveyor; in fact, every conveyor belt is associated with a check-in counter 10. The check-in counter 10 comprises a selection device configured to enable a user to select at least one or more of the activities/operations necessary for check-in, including the registration of the article P. The selection device can comprise a touch screen display 1 1 (condition illustrated in the accompanying figures), or else it can alternatively comprise a display associated with a keyboard and/or mouse for the entry of data and/or the selection of information shown on the display. The counter can include systems for recognizing documents, such as identity documents or travel documents, for example scanning, optical, magnetic systems etc.. Moreover the check-in counter 10 is provided with a system for dispensing the tag for the baggage and also for dispensing any travel documents. The counter may likewise be provided with suitable payment systems, such as credit or debit card readers and the like. The check-in counter 10 is advantageously connected to the control unit 4, which is configured to receive suitable data from the check-in counter 10. The control unit 4 could be integrated into the counter itself and thus receive/send data to the user and control the various operations of the station. Alternatively, several CPUs in communication with one another could be present, each dedicated to a specific task. In greater detail, the user is recognized by means of the check-in counter 10 and starts the procedure of loading the baggage. Once the passenger identification steps have been carried out, the check-in counter 10 can activate a procedure, by means of the control unit 4, which starts the activities of requesting the positioning of the article on the conveyor in order for it to be subsequently sent off to the sorting line 12 via the movement of the conveyor 2, and requesting the weighing of the article P placed in the loading area 2a. As can be seen from the accompanying figures, the accepting station 1 comprises at least one sensor (5, 6, 7) placed on the conveyor 2 and configured to be operatively active in relation to an inspection region comprising at least the loading area 2a of the conveyor 2. In this regard, the sensor(s) will be operating to acquire and process data relating only to the inspection region. In other words, the sensors will not take into consideration data originating from outside the inspection region which represents the potential maximum region of interest for the purposes of the control described below. Merely by way of example, the inspection region can comprise the whole volume extending above the conveyor up to a certain predetermined height and possibly also of the areas projecting laterally relative to the transversal extent of the conveyor itself. It should be noted, however, that the inspection region can be defined via software to enlarge/reduce/modify the volumes of space analyzed according to needs (obviously compatibly with the field of view of the sensors). In a first embodiment, the accepting station 1 comprises a single sensor 5, which can be associated with the conveyor 2 in the loading area 2a or can be placed in a position spaced from the loading area 2a, for example at the entrance port 15 of the tunnel 14, as is illustrated, for example, in figures 1 and 2. In a second embodiment, the accepting station 1 comprises two sensors 5 and 6 (a first sensor 5 and a second sensor 6) associated with the conveyor 2. The sensor 5 (first sensor) is advantageously placed at a distance from the loading area 2a - in particular, it is associated with the entrance port 15 of the tunnel 14 - whereas the sensor 6 (second sensor) is placed in the loading area 2a - in particular, it is associated with the check-in counter 10 (see for example figures 3 to 6). In a third embodiment illustrated in figures 12 and 13, the accepting station 1 comprises three sensors 5, 6 and 7 (a first sensor 5, a second sensor 6 and a third sensor 7) associated with the conveyor 2; the sensors 5 and 7 (first and third sensors) are advantageously placed at a distance from the loading area 2a; in particular they are associated with the entrance port 15 of the tunnel 14, whereas the sensor 6 (second sensor) is placed in the loading area 2a; in particular, it associated with the check-in counter 10.

Obviously, any number and/or arrangement of sensors can be equally adopted provided that it enables the desired inspection region to be monitored and the control algorithms described below to be executed. During a predetermined monitoring condition (condition wherein the system is active), the sensor 5, 6, 7 is configured to process, for example instant by instant (or in a substantially continuous manner), a signal representative of the inspection region comprising the loading area 2a of the conveyor 2. In fact, the signal emitted by the the sensor is representative of the environment which comprises the loading area 2a and thus of everything that is placed inside said environment whether it is moving or not. From a structural standpoint, the sensor 5, 6, 7 can be of varying nature and comprise, for example, at least one (or more) of the following devices: an image detecting camera, in particular an RGB-type camera, an RGB-D camera (or an RGB- Depth camera capable of simultaneously estimating a depth map and a 2D image, in particular a colour one); a 3D light field camera; an infrared camera, in particular a dual infrared depth sensor consisting of an infrared projector and a camera sensitive to the same band, a laser camera, in particular a 3D laser scanner, a time-of-flight camera, a structured light optical measuring system, a plurality of photocells, for example configured to move towards and away from the article P. In general, by means of these types of sensors it is possible to reconstruct the positioning of objects in the area being monitored in their three-dimensional arrangement, and the distances of the scene associated with every pixel and the sensor and optical geometrical characteristics being known, it is possible to determine the 3D coordinates of the framed scene. In other words, by exploiting the data coming from the above-mentioned sensors, the control unit 4 can compute, in real time, a depth map of the scene, i.e. a representation of the scene in which every pixel is associated with the distance from the camera, or the spatial coordinates. The computation of the depth map can be performed directly by the sensor 5 or, alternatively, by the control unit 4. In yet other words, the control unit 4, thanks to the use of the particular sensors described, can know the three-dimensional positioning of objects inside the inspection area pixel by pixel.A possible method for obtaining the depth map exploits the structured light method, in which a known pattern is projected onto the scene and the distance of each pixel is estimated based on the deformations taken on by the pattern. As another alternative (or in combination to improve the level of detail and/or precision of the reconstruction) it is possible to exploit the principle whereby the degree of blur depends on distance. Use can be made of special lenses with different X and Y values of focal length. When circles are projected, for example, they deform into ellipses whose orientation depends on depth. Stereoscopic vision also enables depth to be estimated by observing the same inspection region from two different points. The difference in the position of corresponding points (disparity) in the two reconstructed images is tied to the distance, which can then be calculated with trigonometric calculations. It should be noted, finally, that the additional use of a normal 2D camera, in particular a colour one (for example with a CMOS or CCD sensor) capable of photographing the same inspection region makes it possible, with suitable software algorithms, to 'fuse' the two images (the cloud of points and the two-dimensional image in real colours), thus obtaining a highly realistic reconstruction of the image, of which all the three-dimensional coordinates of every pixel of interest - i.e. the three-dimensional arrangement of the objects contained therein - are however known. For example, in a first preferred, but non-limiting, embodiment of the invention, the sensor 5, 6, 7 comprises at least one image detecting camera and at least one infrared camera. In a second preferred, but non-limiting, embodiment of the invention, the sensor 5, 6, 7 can comprise at least one image detecting camera and at least one laser camera. In a third preferred, but non-limiting, embodiment of the invention, the sensor 5, 6, 7 can comprise at least one image detecting camera and at least one time-of-flight camera. In a fourth preferred, but non-limiting, embodiment of the invention, the sensor 5, 6, 7 comprises at least one image detecting camera and at least one structured light optical measuring system. The active monitoring condition of the sensor 5, 6, 7 comprises a control condition during which the sensor 5, 6, 7 is configured to transmit a signal that will in general be representative of a feature of the article P placed inside a predetermined inspection region, and in particular abutting on the conveyor 2 in the loading area 2a. It should be noted that the sensor is in general capable of providing the control unit 4 with a three-dimensional image of the inspection region and hence also of the article P contained therein (or of providing the control unit 4 with all the data needed in order to reconstruct it) as briefly explained above. This three-dimensional image, despite obviously containing a very large amount of information, is in fact representative of at least one feature of the article P, which can be the shape, size or position of the article P. In other words, during the monitoring condition, the sensor 5, and optionally the plurality of sensors 5, 6, 7, is configured to transmit a signal representative of at least one among: a shape of the article P placed inside the predetermined inspection region, a dimension of the article P placed inside the predetermined inspection region and a position of the article P placed inside the predetermined inspection region.

In fact, for the purposes of the present invention, it could be sufficient for the control unit to be able to know only part of the data acquired, or part of the 3D reconstruction of the scene with an estimate of the depth map, in order to implement the control algorithm detailed below. Therefore, although the control unit 4 has a continuously available 3D reconstruction of the inspection region during monitoring, in a much simpler embodiment, it could be sufficient to receive only some information relating to the article P or a feature thereof in order then to implement the intrusion verification routine. In this regard, knowledge of the dimensions of the baggage, for example in terms solely of maximum height, or height, width and length (which may also be manually entered by the passenger) could, in an extreme simplification of the invention, enable implementation of the intrusion verification routine. As described above, the control unit 4 receives the signals coming from each sensor 5, 6 and 7, and monitors the inspection region comprising the loading area 2a where the baggage will be positioned. In particular, the control unit 4, during the monitoring condition of the inspection region, reconstructs this region in three dimensions (with the resolution allowed/set for the sensor(s)) and, particularly, it reconstructs the article P and any further element that may be located inside the region. This 3D reconstruction takes place on a substantially continuous basis over time, so that the control unit can have at its disposal, instant by instant, the three- dimensional data of the inspection region, which will vary with variations in the bodies C inside it. The monitoring condition could be automatically controlled by the control unit 4 at the moment in which it starts receiving a weight signal from the weight detector 3, or at the moment in which a potential article P has been placed on the conveyor 2. Alternatively, the monitoring can begin only when the weight signal from the detector 3 is in a stable condition, i.e. the article P is stably positioned on the conveyor and the passenger has reasonably already moved away. Obviously, the monitoring could otherwise be timed, for example from the moment in which a tag with a barcode is issued for baggage to be loaded. In this situation, the control unit 4 will typically process both the data of the article and the three-dimensional image of the passenger, or of the portion of the passenger that is situated inside the inspection region (for example the arm that is depositing the baggage).

In this phase, the control unit 4 will have to ensure that the baggage is weighed and that both during and after this phase, until the article P is sent off, no one can tamper with the baggage/article P itself. This serves both to prevent the detected weight from being altered and to prevent the article from being tampered with in any way.

For this purpose, the control unit 4 dynamically generates a suitable virtual control volume

V which will vary according to the article P, its dimensions in particular.

Moreover the virtual control volume V will also change in relation to an additional parameter characterizing at least one body C present in the inspection region and/or the inspection region R and/or the accepting station 1 , as is also explained below.

The virtual control volume V is dynamic in a dual sense: it depends on the shape of the article P and on the additional parameter and is also changed according to the phase of the process as is explained below. The algorithm for generating the virtual control volume

V exploits mathematical calculations based on the three-dimensional data of the inspection region that have been processed. In particular, the control unit 4 is not capable of discerning, in relation to a body C detected inside the inspection region, whether the same is defined only by the article P to be loaded or whether a portion of the individual who is positioning the article on the conveyor, or even a further object accidentally or intentionally introduced into the inspection region, also contributes to the image of the body itself. In fact, the control unit 4 cannot always and/or with the required reliability define a priori what the article P is and what it is not: a virtual control volume V is constructed whose shape depends on what is measured (which could comprise not only the article P). In order to be able to define the virtual control volume V, the control unit is programmed to generate a first containing surface S1 substantially enveloping the body C which the sensors 5, 6, 7 are detecting in the inspection region (or a containing line L1 placed substantially around said body C); see, for example, figure 16. For this purpose, the control unit 4 first projects the acquired three-dimensional image of the body C onto a plane, in particular a plane perpendicular to the advancement direction A of the conveyor. Specifically, the cloud of points is projected onto the plane perpendicular to the axis of the belt, the connected areas are identified and the ones that are smaller than a given threshold (which identifies the noise) are discarded. At this point, an ellipse is computed which has the same area as the region defined by the projection of the article P and the same geometric moments. In other words, a surface or a line is mathematically computed as a function of the body C 'seen' by the sensors in the inspection region. The ellipse is then further processed by mean of convex hull algorithms which, for a given set of points, determine the smallest convex set that contains them all. In other words, the ellipse is mathematically processed in such a way as to 'deform' and envelop all of the points of the body C within it. The resulting surface is substantially an ellipse that encloses within it the body C. Then the resulting region is cut in the lower part with a virtual horizontal plane (for example at a height of 50 mm from the conveyor) in such a way as to filter out the noise in the control phase due precisely to the presence of the conveyor. Only the upper part of the ellipse deformed with the convex hull algorithm is maintained. A new surface (also substantially elliptical) is then computed by expanding the previous surface (deformed ellipse) a first time to prevent the inner surface of the control volume from being too close to the baggage; then the deformed ellipse is expanded a second time to define the outer surface of the control volume. The two expansions have the same "shape", but obviously different "quantities", i.e. the second expansion takes on a greater value than the first expansion. The "shape" of this double expansion can be either isotropic (and thus does not deform the original corresponding ellipse) or anisotropic (it modifies the original shape). The algorithm defines a parameter which makes it possible to decide which type of double deformation to use (isotropic or anisotropic).

The smaller region is then subtracted from the larger one so as to obtain the region of interest, substantially consisting of a kind of vaulted arch that is positioned over the body C. This region can be seen in figure 16. The region is suitably extruded along the longitudinal axis of the belt, i.e. along the advancement direction A (and thus perpendicular to the projection plane) so as to generate the lateral virtual control volume V2. As can be seen in the accompanying figures, in fact, the virtual control volume V2 takes on the shape of a tunnel (slightly raised in relation to the conveyor) below which the baggage lies. Moreover, the control unit 4 proceeds to generate a further front control volume V1 positioned at the conveyor entrance in the entry area of the belt itself where the passenger loads the article P (see figure 9 for example). The front control volume prevents fraudulent access to the tunnel defined by the lateral control volume V2. This front volume V1 can take on different shapes and sizes according to need. Figures 4 and 5 show an example thereof, in which it is round with a curvature similar to that of the tunnel (lateral volume V2) and convex at the front.

Figures 8 and 9 illustrate one with a parallelepiped shape. It should be noted that it can be decided to define a fixed height of the volume V1 , or else a height that is dependent on the article P (for example a function of the height thereof). The two virtual control volumes V1 and V2 are not connected; there exists a gap that divides them, as shown in figure 9. Alternatively, the two lateral and front control volumes V2 and V1 can be in contact (fig. 5) or even partially overlap. It is however worth noting that, as already pointed out, the creation of the virtual control volume V is a dynamic process, not only because it is tied to the dimensions of the article P, but also because it must take account of what is happening during the positioning of the article P on the conveyor. In fact, since it is not possible to define what the article P is and what (which image) belongs to the intrusion a priori (before the creation of the volume), the system proceeds as follows: it defines the intrusion region as the minimum intrusion region constructed according to the above- described algorithm (this is carried out when a stable, non-zero weight of the article is detected) and in the absence of intrusions in the front control volume V1 (the one on the passenger side). A new candidate region is generated following every acquisition and the set of candidate regions of comparison is cleared as soon as a zero or unstable weight is measured with the belt stationary. During the movement of the conveyor 2 (from first conveyor belt towards the second belt) the virtual control volume V is instead "frozen" and a "sending tunnel" - defined by the virtual lateral control volume V2 - is created/maintained. During the sending of the baggage the "freeze" can be achieved in two ways:

1. by maintaining the same projected region.

2. by modifying the region based on an algorithm that does not depend on the current measurement, but rather on the shape of the region defined in the measuring phase. It should be noted, however, that the control volume can optionally be 'frozen' only in respect of the shape of its cross-section, whereas it can decrease in length while the article P is automatically removed from the control area and directed towards the second conveyor belt or towards the sorting area. In more general terms, irrespective of the specific algorithm indicated above and also of the specific mathematics for generating the virtual control volume V and the exact geometry, the control unit 4 is programmed to: - in a first time instant -

> receive the signals from the sensor 5, in particular from the plurality of sensors 5, 6, 7,

> as a function of the received signals, to generate a geometrical representation, in particular to generate a two-dimensional projection of the three-dimensional image of the scene, thereby obtaining a two-dimensional image of a body C placed inside the inspection region (this step is schematically illustrated in figure 16),

> as a function of said geometrical representation, to calculate a first containing surface S1 substantially enveloping said body C, or a containing line L1 placed substantially around said body C (again see figure 16).

During the monitoring condition of the inspection region and during a second time instant following the first time instant, the control unit 4 is configured to: receive further signals from the sensor, in particular from the plurality of sensors, as a function of said signals, generate a further geometrical representation, in particular a two-dimensional one, of a body C placed inside the inspection region, as a function of said geometrical representation, and generate a second containing surface S2 substantially enveloping said body C, or a second containing line L2 placed substantially around said body C. In other words the algorithm generating the containing surface or line (in the example case, the deformed ellipse enveloping the projection of the body C) operates continuously as the two-dimensional representation of the body C varies over time. The control unit 4 further compares the value of a dimensional parameter of said first and said second containing surface S1 , S2 or of said first and second containing lines L1 , L2 (for example the area or the length of the segments or the geometric moment, etc.). Following the comparison step, it verifies that the value of the dimensional parameter of the second surface has a variation in relation to the value of the dimensional parameter of the first surface that is zero (or below a predetermined minimum threshold). In fact, the value of the predetermined threshold is set so as to establish whether the dimensional representation of the body C detected in the second time instant has remained substantially unchanged (for example on a dimensional level) in relation to the dimensional representation of the body C detected in the first time instant: in this manner, the control unit substantially verifies a stability in the detected shape and size. If such variation is within the predetermined threshold, the control unit 4 will define the control condition wherein it determines whether there is an intrusion condition as a function of the signal received from the sensor following the generation of the virtual control volume V. If such variation is outside the predetermined threshold, i.e. if a variation in the two- dimensional image of the body C has actually been detected, the control unit 4 will repeat the previous steps in the event that such variation is a reduction in the dimensional parameter, or the containing surface or line has been reduced. Conversely, in the event of a detected variation bringing about an increase in the containing surface or line, the control unit 4 will determine whether there is an intrusion condition as a function of the signal received from the sensor following the generation of the virtual control volume V. In fact, a variation in the dimensional parameter beyond the predetermined threshold serves to identify a certain variation in the shape and dimensions of the body C in the second time instant compared to the first time instant. The variation beyond the predetermined threshold enables the control unit to determine an instability of the body C inside the inspection region (change in the shape of the body C detected by the control unit 4). In the specific case concerned, the preferred implementation requires that a number of dimensional parameters be compared in order to improve the decisional reliability of the algorithm. In order to compare the candidate control volumes, or the calculated surfaces, the area and height of the calculated geometries in particular are taken into consideration. Obviously, the dimensional parameters taken into consideration could be different from the ones indicated and there could also be more than two. As described above, if the control unit 4 detects an increase in the dimensional parameter, this means that an object is probably entering into the visual field monitored by the sensors and therefore the intrusion verification mode is activated using the last computed virtual control volume V. Conversely, a reduction in the dimensional parameter means that an object (for example the passenger's arm) has moved away - or is moving away - from the area monitored by the sensors and therefore that the new calculated containing surface or line is more circumscribed to the article P. In fact, the control unit 4 is configured to enable only a reduction in the dimensional parameter of the body C to identify a step of correct identification solely of the article P on the conveyor (condition illustrated in figure 16) with a consequent definition of the optimal virtual control volume V. Once the dimensional stability of the body C has been reached (a condition reached only when the article P is on the conveyor and in particular inside the inspection region), the control unit 4 in fact establishes that the size of the body C is the size of the article P alone. Once the stability of the dimensional parameter has been reached, an increase thereof can be detected only if the presence of a further body is detected inside the inspection region; this condition can be determined by an attempt to tamper with the article P after it has been positioned on the conveyor 2 (a condition illustrated in figure 18). Therefore, if such a variation is an increase in the dimensional parameter, the control unit 4 will not recalculate the containing surface but rather start the intrusion monitoring procedure in order to signal a possible attempt to tamper with the article P. In greater detail, during the step of generating the geometrical representation of the body C placed inside the inspection region, the control unit 4 is configured to determine, as a function of the signal received from the sensor, at least one of the following parameters relating to the body C placed inside the identification region: a cloud of points NP of the body C (condition illustrated in figure 16), a cross- section of the body C, an outline of the body C, a shape of the body C, and a dimension of the body C.

Therefore, as a function of said parameter, it generates a flat geometrical representation of the body defined by one or more surfaces or by one or more closed outline shapes, and calculates the value of the dimensional parameter(s) of said flat geometrical representation, said dimensional parameter comprising at least one among: a moment of inertia of the geometrical representation, an area of the geometrical representation, a perimetral extent of the geometrical representation, and, as a function of the value of the dimensional parameter of said flat geometrical representation, it calculates the surface enveloping said flat geometrical representation, or else the line placed around said flat geometrical representation.

As indicated above, the virtual control volume V is not only a function of the size or geometry of the baggage, but rather the control unit 4 varies the geometry of the same also as a function of a further parameter in such a way as to be able to take into account further situations relating to the automatic check-in procedure. First of all, the virtual control volume V can be dynamically modified over time during the same control step. For example, account can be taken of the presence of bodies C - such as users - inside the inspection region R, i.e. inside the visual field of the sensors. When generating the virtual control volume (instant by instant), the control unit 4 can in fact also take into account an additional parameter characterizing the body C; this additional parameter of the body C is tied, for example, to the velocity of the same in terms of modulus, direction and/or sense, expressed in absolute terms or in relative terms. By way of example, the additional parameter characterizing the body C can be selected from one or more among a modulus of the absolute velocity of the body C, a direction of the absolute velocity of the body C and a sense of the absolute velocity of the body C. Alternatively, it can be selected from among a modulus, a direction and a sense of the relative velocity of the body C in relation to the article P. A body that moves towards the article P at a certain direct velocity towards the article itself will generate a different variation in the control volume (in general the latter will be increased in size, since the mentioned configuration appears to be more dangerous in terms of potential intrusion) relative to the same body, in the same position, with the same direct velocity but away from said article P.

Thanks to the aforesaid sensors which pick up the image of the scene over time it is possible to compare two successive images and not only to identify the position of significant bodies C, but also to establish the velocity thereof in vectorial terms. In a further example, the additional parameter characterizing the body C can also be a path of movement y of the body C, a profile, a part of the profile, or a parameter that is a function of the profile of the same body C. It should be noted that the variation in the virtual control volume V can additionally (or alternatively) be dependent on an additional parameter characterizing the accepting station 1 . In this case the parameter can comprise an operating condition of the accepting station 1 , such as a condition of supervision by a dedicated operator or a condition of an operator's presence for the supervision of a plurality of stations or a working condition with no operator assistance. In the case of an operator's presence, the control volume can be reduced, since it is judged that the operator's presence leads to the dual effect of reducing the intrusion attempts and having an additional check performed by the operator him/herself during loading and acceptance of the baggage. It is moreover also possible to take into account an additional parameter characterizing the inspection region R, in the sense that, for example, a security level can be set and assigned to the inspection region (high, medium or low security), which may or may not increase the sensitivity and security of the surveillance system and vary the size of the virtual control volume V accordingly. An alert condition in the place where the accepting station 1 is located can also contribute to changing the sensitivity of the system, or influencing the variations in the control volume V to a greater or lesser extent. As described above for the specific example embodiment, the unit 4 is configured to define a control condition during which it generates a virtual control volume V placed at least partially around or enveloping the article P. The virtual control volume V is calculated by the control unit 4 as a function of the signal received from the sensor, in particular from the plurality of sensors (5, 6, 7). Then the control unit determines whether there is an intrusion condition in said control volume. As mentioned, the virtual control volume V can be of a static type, that is, determined in an instant preceding the intrusion control phases and hence maintained fixed, or it can be of a dynamic type, i.e. be modified in shape and/or size based on how the control situation evolves over time as mentioned above, taking into account the additional characterizing parameter (e.g. bodies moving in the inspection region and/or alert and/or human monitoring conditions in the check-in areas). In a preferred, but non-limiting, embodiment of the invention, the control unit 4, as a function of said signal, estimates the shape on a three-dimensional level (see the representation SP in figure 15) and the dimensions of the article P placed on the conveyor 2; in the latter configuration the control unit 4 can be configured to estimate the maximum size of the article P and verify whether they fall within certain predetermined maximum limits. If the article exceeds the allowed dimensions, the control unit 4 can stop the procedure of registering the article P and inform the user of the stop via the check-in counter 10. As described above, during the control condition, the unit generates a representation of the article P and as a function of said representation generates the control volume V: the virtual control volume V varies as a function of the article P placed inside the predetermined inspection region. In particular, said virtual control volume V has a size and/or geometry and/or position calculated by the control unit 4 as a function of said signal. In greater detail, the control unit 4, as a function of the signal received during the control condition, is configured to calculate at least one parameter of the virtual control volume V and in general a plurality of such parameters; said parameter comprises at least one among: a shape of the virtual control volume V, a maximum size of the virtual control volume V measured along the advancement direction A, a maximum size of the virtual control volume V measured along a direction perpendicular to the advancement direction A, a position of the virtual control volume V in relation to the position of the article P on the conveyor 2 and a minimum distance between the virtual control volume V and article P. As can be seen for example from figure 7, the control unit 4 is configured to generate a virtual control volume V spaced, in particular upwardly spaced, from the conveyor 2. In particular, the virtual control volume V has a minimum distance D from the exposed surface of the conveyor 2 smaller than 100 mm, in particular comprised between 10 and 90 mm, even more in particular comprised between 20 and 60 mm.

As can be seen for example from figures 4-6, 8, 9, the virtual control volume V comprises at least one lateral control volume V2 configured to cover the article P, at least partially. The lateral volume V2, along a cross-section perpendicular to the advancement direction A, has a substantially "C" or "U" or "V" shape (see for example figure 7) having a concavity facing the exposed surface of the conveyor 2 adapted to abuttingly receive the article P; in particular, the lateral control volume V2 defines a tunnel shape or an elongated one having a cross-section suggesting a "C" or "U" or "V" shape. In greater detail, the lateral volume V2, along a cross-section perpendicular to the advancement direction A, has a cross-section delimited by an inner edge 8 and an outer edge 9 spaced from each other and defining the thickness of said lateral volume V2 (see for example figure 7). In particular, the first and second edges 8, 9 are placed at a minimum distance from each other comprised between 50 and 150 mm. The thickness of said lateral volume V2 may or may not be constant along the whole longitudinal extent of the volume itself or along the advancement direction A. Moreover, the inner surface of the lateral control volume V2 is at a distance preferably comprised between 50 and 90 mm, whereas the outer one is preferably between 150 and 190 mm. The control unit 4 is configured to calculate the distance between the inner edge 8 and outer edge 9 of the lateral volume V2: the distance between the inner edge 8 and the outer edge 9 is variable along the extent of the cross- section. As can be seen from figures 5, 6, 8, 9, the lateral volume V2 extends along the advancement direction A between a first and a second end portion respectively turned towards the loading area 2a and the unloading area 2b of the conveyor 2. In fact, the lateral volume defines a through cavity extending between the first and second end portions, configured to contain the article P placed on the conveyor 2. As can be seen from the accompanying figures, the virtual control volume V comprises a front volume V1 placed in the first end portion of the lateral volume V2. The front volume V1 extends along a prevalent plane of extension and is configured to at least partially cover, according to a view along the advancement direction A of the article P on the conveyor 2, the front cross- section of the through cavity. The above-described modes of generating the virtual control volume V make clear not only the fact that said control volume is generated dynamically and depends on the shape of the article, but also that, since software routines and mathematical algorithms are involved, any shape and type of control volume could be defined as an alternative to the one described. Merely by way of example, in a further embodiment, the control unit 4 can generate a virtual control volume V which is configured to envelop the article P at least partially (see figures 23 and 24). In particular, in the latter embodiment described, the control volume V can comprise a plurality of volumes of any shape, of a parallelepiped shape in the illustrated example, aligned (or not) and placed in sequence side by side in such a way as to at least partially cover the article P. In the embodiment illustrated in figures 23 and 24, the virtual control volume V comprises a series of volumes having a parallelepiped shape and inclined in relation to the vertical, spaced from one another, and aligned along the advancement direction A in such a way as to at least partially cover the article P. The latter geometry makes it clear that for an effective control of intrusions it can be sufficient to create a sort of virtual maze in which it is substantially impossible to be able to enter without being detected, it not being necessary, however, to continuously monitor the entire inspection region. In this last situation as well, the overall dimensions and number of the elements making up the the virtual control volume V depend on the dimensions and shape of the baggage; for example, the number of the parallelepiped control elements can depend on the overall length of the article P, whereas their height can depend on the height of the article P. Obviously, the shape of the elements illustrated in figures 23 and 24 could clearly be different, for example in the shape of a lens, thus curvilinear, concave or convex and of variable thicknesses and obviously differing from each other in shape. The important thing is to generate a control volume that does not enable a passenger to be able to simply access the article P without such access being detected and signalled as an intrusion. The intrusion verification steps are the following.

In relation to the lateral control volume V2, an identification is made of the part of the measured cloud of points NP whose projection falls in the lateral control volume V2. It should be noted that it is possible to limit the analysis to all of these points or only to those that fall in a certain range of positions along the belt. This means that it is possible to extrude the region dynamically along the whole length of the belt or only on a part thereof. Secondly, a determination is made of the connected projected regions, if they exist, which exceed a certain threshold area (potential intrusions). Finally, it is verified whether these potential regions of intrusion intersect the outer or rear edge of the lateral intrusion volume V2. It should be noted that verifying the intersection of the possible intrusion with the outer edges of the virtual control volume V has the aim of making the algorithm more robust, since it allows possible oscillations of the baggage in the sending phase (intrusion from the inside) or the occurrence of noise not filtered during the acquisition phase ("fluctuating" noise) not to be considered as intrusions. Only in the event that the connected projected regions exceed a certain threshold area and the regions of intrusion intersect the outer or rear edge of the lateral intrusion volume V2 will the control unit 4 determine the presence of an intrusion. In addition, it is possible for the intrusion verification algorithm also to check that the potential intrusion region cuts both surfaces of the control volume (outer and inner). If the violated virtual control volume V is outside the belt (large-sized baggage and/or baggage close to the edge), moreover, it is verified whether the intrusion is also "prolonged" inside the belt under control where the baggage has to be. In any case, in more generic terms, the intrusion verification algorithm determines whether other geometric characteristics (area, shape and position) of the candidate intrusion have been verified inside the control volume as a function of suitable thresholds in order to decide whether or not there has been an intrusion. In the event of an intrusion, the process of weighing or transferring the article is interrupted and must be repeated; a signal or alarm is likewise generated. In relation to the front control volume V1 , the procedure for determining intrusions is similar, but not identical. In fact, the front control volume V1 can be created by one or more sensors (typically more than one). It is a barrier endowed with thickness: first the points that are located inside the cloud of points are segmented from the latter, then they are projected onto two reference planes (frontally and from above; this is possible because the front control volume V1 is not a surface but rather has thickness, and therefore potentially has three projection planes) and a calculation is made of the area of the maximum connected region thus obtained. If it exceeds a fixed threshold, the presence of an intrusion is considered. Although the specific (and non-limiting) algorithm described above exploits the projections of the bodies measured in the virtual control volume V in order to define whether there is an intrusion, the idea at the basis of the present invention is broader and is tied to an actual volumetric analysis of the intrusion, i.e. if the presence of a foreign volume beyond a certain threshold is detected in the control volume, an intrusion is signalled; otherwise no alarms are signalled, nor is the process interrupted even if the presence of an object is detected in the virtual control volume V. In general terms, in fact, the control unit 4, following the definition of the virtual volume V, is configured to perform at least the steps of selectively monitoring the virtual control volume V and detecting intrusion conditions therein. In greater detail, following the determination (calculation) of the virtual control volume V, the control unit 4 is configured to: receive the signal from the sensor, in particular from the plurality of sensors (5, 6, 7), and as a function of said signal, to determine:

o a dimensional parameter representative of a volume of a body C placed inside said virtual control volume V;

o compare said dimensional parameter representative of the volume of the body C placed inside the virtual control volume V with a reference dimensional threshold; and

o determine an intrusion condition if said dimensional parameter is greater than the reference dimensional threshold.

In detail, the dimensional parameter of the body C can comprise at least one, and also more than one, in a combination among: a detected volume of the body C, said detected volume being the only volume placed inside the virtual control volume V, an area of the outer detected surface of the body C, said outer detected surface being the only surface that is situated inside the virtual control volume V, a calculated moment of inertia of the portion of the body C placed inside the virtual control volume V, an area of the projection of the portion of the body C placed inside the virtual control volume V onto at least one virtual reference plane X, an area of a cross-section of the portion of the body C placed inside the virtual control volume V, and a perimeter of the projection or of the cross- section of the portion of the body C placed inside the virtual control volume V. The control unit 4, if the value of the dimensional parameter of the body C is greater than the value of the reference dimensional threshold, is configured to determine (and signal) an intrusion condition of the accepting station 1. In fact, the dimensional threshold parameter is determined in such a way as to enable the identification of bodies which may represent intrusion attempts by the user or objects that can tamper with the article placed on the conveyor 2. Preferably, the control unit 4 determines the intrusion condition if it detects the presence of a body C intersecting an outer surface of the virtual control volume V, and the dimensional parameter is greater than the reference dimensional threshold. In fact, the control unit 4 is configured to detect bodies larger than a certain size which pass through at least the outer surface of the control volume V: these conditions enable it to identify intrusion attempts by objects and/or people inside the control volume in order to tamper with the article P. The control unit 4 is further configured to ignore the intersection of bodies of a small size with the control volume V, bodies which could not actually represent a danger with respect to tampering of the article P. Moreover, the control unit is configured to ignore conditions in which a body placed inside the volume V might be detected but does not intersect the outer surface of the same. The latter condition makes it possible to minimize the detection of false intrusions, for example caused by an unwanted movement of the article on the conveyor 2. The article P could in fact oscillate and intersect the control volume V: if the oscillation of the article P is modest and such as not to intersect the outer surface of the control volume V, the control unit 4 will ignore the detected intersection. In a preferred, but non-limiting, embodiment of the invention, during the control condition, the control unit 4 estimates a first projection of the portion of the body C placed inside the virtual control volume V onto a first virtual reference plane X (figure 22), and calculates a value of the dimensional parameter of said first projection W (figure 22). The dimensional parameter of said first projection comprises at least one among: an area of the first projection W, a perimetral extent of the first projection W, a moment of inertia of the first projection W, a parameter proportional to the preceding ones or a combination of the same.

Finally, the control unit compares the value of the dimensional parameter of said first projection W with the value of a reference dimensional threshold. The control unit 4 is configured to determine an intrusion condition if the value of the dimensional parameter of said first projection is greater than the value of the reference threshold. This intrusion detection algorithm can be used for one of the defined virtual control volumes V, for example for the lateral volume V2. In a further embodiment, the control unit 4 estimates a second projection Z of the portion of the body C placed inside the virtual control volume onto a second virtual reference plane Y (figure 22), and calculates a value of a dimensional parameter of said second projection Z; in this case as well the dimensional parameter of the second projection comprises at least one among: an area of the second projection Z, a perimetral extent of the second projection Z, a moment of inertia of the second projection Z, and a parameter proportional to the preceding ones or a combination of the same. Obviously, the dimensional parameter for the first reference plane and the one for the second reference plane may or may not be analogous. Finally, the control unit 4 compares the value of the dimensional parameter of the second projection (Z) with the value of a second reference dimensional threshold. The control unit 4 then determines an intrusion condition upon the occurrence of at least one of the following conditions, and particularly both of the following conditions: the value of the dimensional parameter of said first projection is greater than the value of the reference threshold, and the value of the dimensional parameter of said second projection is greater than the value of the reference threshold. If an intrusion condition is detected in the virtual control volume V, the unit 4 will block the operations of registering the article P and notify the user accordingly via the check-in counter 10. In such a condition, the user will have to start a new procedure of registration of the article P and again carry out the weighing of the article P. If the passenger needs to load only one article P, the procedure of weighing and sending off the baggage envisages that the article be positioned on the conveyor 2, that its dimensional measurements be taken by means of the aforesaid sensors 5, 6, 7 and that the virtual control volume V is then generated. The lateral volume V2 around the baggage and the front shield V1 constitute the actual mechanism of analysis of intrusions (which serves to prevent attempts to alter the measurement). It is enough that one of the two analyses is positive in order to signal an intrusion. Moreover, a decrease in weight or the occurrence of instability while the belt is stationary can be used by the control unit in any case to establish (or confirm) an intrusion. If the weighing process takes place without any problems, the virtual control volume will be maintained active and the conveyor 2 activated so as to direct the article towards the sorting centre. Once the baggage has been sent off the intrusion control system will be deactivated and a new check-in process can be started for another passenger. If the passenger has to load two articles P, the process for the first article is the same. However, the article is weighed and moved from the first conveyor belt to the second conveyor belt (see the sequence in figures 9 and 10). Once it has arrived on the second conveyor belt, a virtual shutter VP is created, which prevents the first article P from being removed. The virtual control volume is deactivated and another article P can be positioned on the first conveyor belt, repeating the weighing and control steps exactly as in the above-described case. When the second article is also stabilized, the virtual control volume V is created and the article is weighed. The virtual shutter is deactivated and, with the tunnel (lateral control volume V2) active, both of the articles are conveyed towards the sorting centre. The rear virtual shutter (on the tunnel side) is constructed in a manner analogous to that of the front control volume V1 , and the intrusion detection system is likewise analogous. The difference is that the dimensions are fixed in relation to the specific machine on which the same shutter is generated (this is for functional, not algorithmic requirements). Obviously, as it is a virtual volume generated by the control unit 4, there are no particular limits in terms of the form and geometry that the virtual shutter can take on.

The latter behaves like a physical shutter at the mouth of the tunnel. Conceptually, it opens (is deactivated) when the article P is passing and closes again (is activated) after it has passed. This serves to prevent the possibility of an article P being removed from the belt once the analysis of intrusions on the belt is deactivated (for example because there is no other baggage).

In general, if the front control volume V1 and the lateral control volume V2 are activated, the virtual shutter VP is not activated and vice versa.