METHOD AND APPARATUS FOR WRAPPING A LOAD WITH A FILM OF EXTENSIBLE

MATERIAL

Technical field

[01] The present invention relates to a method for wrapping a load comprising one or more products with a film of extensible material as well as an apparatus for actuating this method.

Prior art

[02] In the technical field of load packaging comprising one or more products, the products are generally arranged on a support platform made up, for example, of one pallet or several stacked pallets.

[03] The products, which may consist of a series of packages distributed on the pallets, are generally wrapped with a film of extensible material so as to form a single package of larger dimensions. The packaging thus formed is easier to handle and transport.

[04] The wrapping operation of the products takes place through the use of an apparatus which is moved along the perimeter of the palletized products with the film of extensible material being unwrapped from a reel thus being the packaging obtained after a predetermined number of laps made around the pallet.

[05] A type of apparatus for wrapping the products comprises a guide carriage which supports a reel of extensible material being driven in rotation so as to unwrap the material in the operational step. The carriage comprises moving means and a motor unit, suitable for actuating the moving means to exert a propulsive force onto the carriage. Associated with the carriage is a laterally projecting arm which mounts a contact roller at one end thereof that is configured to engage the profile of the to-be-wrapped products thereby producing a reaction force which causes the motor unit to follow the perimeter of the products without further turning towards the latter.

[06] An example of an apparatus for wrapping of the aforesaid type is illustrated in the Italian patent 1095637.

[07] A further example of the apparatus is described in the patent EP 2 709 91 1. The patent discloses an apparatus for wrapping products with a film of extensible plastic material which comprises a motorized carriage consisting of a support body and a body guide rotatably connected to the support body. The support body comprises a pair of non -steering wheels and supports an upright whereon a film feeding unit on reel is arranged. The guide body comprises a pair of directing steering wheels mounted on a support driven by a steering wheel. The guide body is also provided with a feeler arm which allows to follow the profile of the to-be-wrapped products.

[08] A drawback of the aforesaid type of apparatus is the presence of the feeler arm, which allows to follow the profile of the palletized products but represents a significant constraint for the apparatus. Moreover, an aspect to be considered is that this type of apparatus does not allow to wrap a load exhibiting an irregular shape along a direction orthogonal to the load bearing plane, for example a load exhibiting one or more portions projecting outwards at a height different from that at which the feeler arm operates. In this case, in fact, the feeler arm cannot detect the projecting portion and a collision of the apparatus with the load may occur.

[09] To overcome this problem, a type of apparatus was developed which is capable of wrapping the products and does not require use of any feeler arms.

[10] An example of this type of apparatus is shown in the international patent application WO 2017/025870. The patent application describes an apparatus for wrapping a load which comprises a carriage associated with guide means, and a column mounted on the carriage, which carries a reel of plastic material. The apparatus comprises sensor means for detecting surfaces and/or edges of the load along a direction substantially orthogonal to the lying plane of the load, the sensor means being suitable for sending signals to a control unit which signals are analysed to define a peripheral contour of maximum encumbrance of the load and to calculate, based on the contour, a wrapping path of the apparatus around the load. The method implemented by the apparatus provides for activating the sensor means to detect a surface and/or an outer edge closer to the apparatus and to carry out a detection lap around the load at a predefined distance from the load so as to detect and save the surfaces and/or the edges of the load. Based on the data acquired from the sensor means on the surfaces and/or the edges of the load, the peripheral plan contour of the load and the wrapping path around the load are calculated.

[1 1 ] A disadvantage of the wrapping method herein described is the increase in terms of time required to carry out the wrapping considering that it is required to carry out a detection lap around the load in order to be able to detect the data relating to the surfaces and/or edges of the load and that the lap generally occurs at a reduced speed compared to the speed adopted to wrap the load. In addition, the method involves storing data on the surfaces and/or edges of the load, as well as calculating a wrapping path, resulting in the need to store a significant amount of data in the control unit.

[12] A need is therefore felt to devise a method which allows a load to be wrapped in a simple and rapid manner.

Presentation of the invention

[13] The aim of the present invention is to solve the problems as above mentioned by devising a method and an apparatus for wrapping a load comprising one or more products with a film of extensible material allowing to perform wrapping operation with an increased degree of autonomy.

[14] Within this aim, it is a further object of the present invention to provide a method for wrapping a load which allows to wrap a load exhibiting an irregular shape, in particular along a direction substantially orthogonal to the lying plane of the load.

[15] A further object of the invention is to provide a method which allows to wrap a dynamic load, i.e. a load exhibiting a shape that can vary over time.

[16] A further object of the present invention is to devise a method which allows to optimize the time required to wrap the extensible film around the load.

[17] An object of the invention is to provide a method for wrapping a load with a film of extensible material that allows to follow the shape of the load in a precise and reliable manner.

[18] A further object of the invention is to provide an apparatus for the wrapping of products of simple construction and functional concept, which is certainly reliable, of versatile use, and relatively cost-saving.

[19] The aforementioned objects are achieved, according to the present invention, by a method and apparatus for wrapping a load comprising one or more products with a film of extensible material according to claims 1 and 9, as well as by a computer program according to claim 5 and by a method for controlling the movement of the apparatus according to claim 6.

[20] The present invention relates to a method for wrapping a load comprising one or more products with a film of extensible material, in particular palletized products, which comprises the step of providing, in a work environment in which said to-be-wrapped load is arranged, an apparatus for wrapping products with a film of extensible material provided with at least one device for acquiring three-dimensional images.

[21] The method provides for detecting by means of said device for acquiring three-dimensional images, at least one three-dimensional image of a first visible portion of said load so as to have a view of the visible encumbrance.

[22] The method provides for actuating said apparatus so as to wrap said film of extensible material around said load.

[23] At the same time, the method provides for detecting, moment by moment, three- dimensional images of visible portions of said load and moving said apparatus around said load based on said three-dimensional images detected.

[24] The method, object of the present invention, has the effect of following the shape of the load with precision and reliability since a first three-dimensional image of a visible portion of the load is detected to direct the apparatus around the load and subsequent three- dimensional images of visible portions of the load to adjust the direction of the apparatus.

[25] Advantageously, the method allows to wrap a load exhibiting an irregular shape, in particular along a direction substantially orthogonal to the lying plane of the load, in addition to a dynamic load, i.e. a load which exhibits a shape which can vary over time, for example if the load is provided with movable portions that may create projections not present in the initial configuration. It is in fact to be considered that three-dimensional images of the visible portions of the load are detected as the apparatus proceeds around the load, so any changes in the shape of the load over time are easily detected.

[26] Advantageously, the method does not provide for processing an overall three-dimensional model of said load since the apparatus moves around the load on the basis of the three- dimensional images of the visible portions of the load.

[27] Advantageously, the method does not provide for calculating a wrapping path which said apparatus must follow in order to wrap said film of extensible material around said load. It is observed that it is not necessary to store a wrapping path and a three-dimensional pattern of the load in the apparatus, with an advantage in terms of simplification of the wrapping method.

[28] Preferably, the step of providing, in a work environment in which said to-be-wrapped load is arranged, an apparatus for wrapping a load with a film of extensible material provided with at least one device for acquiring three-dimensional images, provides for arranging said apparatus in a suitable position to display at least a portion of said load.

[29] Preferably, the step of starting to wrap said film of extensible material around said load provides for attaching said film of extensible material to said load automatically or manually.

[30] Object of the present invention is also a computer program comprising instructions which, when the program is being executed on an electronic computer, cause the computer to perform the steps of detecting, by means of said device for acquiring three-dimensional images, at least a three-dimensional image of a first visible portion of said load and of actuating said apparatus so as to wrap said film of extensible material around said load, and, simultaneously, detecting moment by moment, three-dimensional images of visible portions of said load and moving said apparatus around said load based on said detected three-dimensional images.

[31] It is further an object of the present invention a method for controlling the movement of an apparatus for wrapping a load with a film of extensible material provided with a device for acquiring three-dimensional images.

[32] The method for controlling the movement of said apparatus provides performing a predetermined control.

[33] The method provides for said apparatus receiving said control.

[34] Finally, the method provides for activating a mode of operation of said apparatus corresponding to said executed control.

[35] Preferably, said control comprises an acoustic signal or a radiofrequency signal. The control can be, for example, a vocal control.

[36] According to an aspect of the invention, the step of carrying out a predetermined control provides for an operator to perform a predetermined movement of the body in the field of view of said device for acquiring three-dimensional images. [37] By way of example, this movement can be a specific gesture performed with an arm or a hand, preferably facing towards said device for acquiring three-dimensional images.

[38] Preferably, the method provides, then, for detecting said predetermined movement by means of said device for acquiring three-dimensional images.

[39] Preferably, the step of activating an operating mode of said apparatus provides to follow the trajectory of said operator who has performed the movement.

[40] Preferably, said step of following the trajectory of said operator provides the operation of sending a control signal to the motor unit of said apparatus so that the trajectory of said apparatus substantially corresponds to the trajectory of the operator.

[41] Alternatively, the step of activating an operating mode of said apparatus provides to start or stop a cycle of wrapping the products upon detection of a specific movement.

[42] It is also an object of the invention a method for increasing the safety of an apparatus for wrapping a load with a film of extensible material which provides to detect, by means of said device for acquiring three-dimensional images, an obstacle, which can be an object or a person, present in the path of said apparatus around said load.

[43] Subsequently, the method provides the step of sending a control signal to a motor unit of said apparatus to progressively decrease the speed of said apparatus and, finally, to stop said apparatus so as to avoid any impact with said obstacle.

[44] The apparatus for wrapping a load comprising one or more products, in particular palletized products, with a film of extensible material comprises a guide carriage provided with a frame associated with moving means suitable for moving said guide carriage; a motor unit suitable for actuating said moving means; at least one reel of extensible material mounted on a support member associated with said guide carriage, said reel of extensible material being driven in rotation by an actuation unit to release, in the operational step, said extensible material to be wrapped around said products.

[45] The apparatus comprises at least one device for acquiring three-dimensional images comprising a stereoscopic camera configured to detect three-dimensional images of visible portions of said to-be-wrapped load.

[46] Preferably, said stereoscopic camera is associated with an upper portion of said support member.

[47] It is noted that the stereoscopic camera allows to simulate binocular vision, which is characteristic of man, making it possible to implement a movement around the load to carry out the "anthropomorphic" wrapping.

[48] The apparatus also comprises a processing and control unit adapted to receive, from said stereoscopic camera, three-dimensional images of visible portions of said to-be-wrapped load, said processing and control unit being configured to send, based on said three- dimensional images acquired, control signals to said motor unit so as to move said apparatus in order that said load is wrapped with said film of extensible material.

[49] Preferably, the support member extends in a longitudinal direction thus forming a support column.

[50] Preferably, said moving means comprise a pair of steering wheels connected to a part of said frame, and a further pair of wheels connected to an opposite part of said frame.

[51] Preferably, said pair of steering wheels are associated rearwardly with said frame and said further pair of wheels are connected in front of said frame.

[52] Preferably, said pair of steering wheels can be oriented by controlling a steering mechanism which is driven by said motor unit.

[53] Advantageously, a first angular position sensor is associated with said steering mechanism, said first angular position sensor being adapted to detect the angular position of said pair of steering wheels and to transmit said data relative to the angular position of said pair of steering wheels to said control and processing unit.

[54] Preferably said apparatus comprises a manoeuvring device associated with said support member, said manoeuvring device comprising a guide member which can be driven in rotation around a rotational axis in order to select the direction that said guide carriage has to follow.

[55] Advantageously, a second angular position sensor is associated with said guide member and is adapted to detect the angular position of said guide member and to transmit the data relating to that angular position of said guide member to said processing and control unit.

[56] Preferably the data acquired respectively from said first sensor and said second angular position sensor are transmitted to the control unit such that a control signal is sent to said motor unit resulting in said pair of steering wheels assuming an angular position corresponding to the angular position imparted to said guide member.

[57] Preferably, each said angular position sensor is made up of an encoder.

[58] According to an advantageous aspect of the invention, said manoeuvring device comprises a control bar articulated to said guide member.

[59] Preferably, said control bar is rotatably actuatable about a substantially horizontal axis of rotation.

[60] Preferably, said control bar is movable between a first inactive configuration, wherein it is preferably raised, and a second activated configuration, wherein it is preferably lowered.

[61] Preferably, a safety member is connected to the front of said frame which acts as a protection barrier for said apparatus during operation.

[62] Preferably, said safety member is made up of a cap.

[63] Alternatively, said safety member is formed by a bar exhibiting a curved surface which is connected, at the ends thereof, to said frame.

Brief description of the drawings [64] The details of the invention will become more apparent from the detailed description of a preferred embodiment of the apparatus for the wrapping of a load comprising one or more products with a film of extensible material according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 shows a perspective view of the apparatus at issue;

Figures 2, 3, 4 and 5 respectively show a plan view, a perspective view, a side view and a front view of the apparatus during operation;

Figures 6 and 7 show respective perspective views of the apparatus in different operational steps.

Embodiments of the invention

[65] With particular reference to these figures, the reference numeral 1 as a whole indicates the apparatus for wrapping a load comprising one or more products with a film of extensible material according to the present invention.

[66] The load 2 may comprise a single to-be-wrapped product or a batch of products arranged for example on a pallet or on a series of stacked pallets.

[67] The apparatus 1 comprises a guide carriage 3 provided with a frame 4 associated with moving means 5 being suitable for moving the carriage 3.

[68] Preferably, the moving means 5 comprise a pair of steering wheels 6 connected to a part of the frame 4, and a further pair of wheels 7 connected to an opposite part of the frame 4.

[69] The pair of steering wheels 6 are associated at the rear of the frame 4 and are oriented upon control of a steering mechanism 8 which is driven by a motor unit 9.

[70] Preferably the motor unit 9 is powered by at least one self-standing electrical supply unit installed on the guide carriage 3 comprising one or more batteries.

[71] The steering wheels 6 are rotatably mounted on a substantially horizontal axle which is solidly constrained by means of a connecting member, not shown, to the steering mechanism 8.

[72] The steering mechanism 8 comprises a rotation shaft, not visible in the figures, which extends longitudinally and is associated at one end thereof with the connecting member. At the top of the rotation shaft a driven pulley 10 is arranged which is able to receive the motion from a driving pulley 1 1 via transmission means 12.

[73] The transmission means 12 are made up by a belt wrapping around the pulleys 10, 1 1 , for example.

[74] The driving pulley 1 1 is driven in rotation by the motor unit 9 which comprises a speed reducer.

[75] A first angular position sensor 13 is associated with the driven pulley 10, which position sensor is suitable for detecting the angular position of the shaft and therefore the angular position of the pair of steering wheels 6 integrally connected thereto. The first angular position sensor 13 is configured to detect the data relating to the angular position of the steering wheels 6 and to transmit this data to a control and processing unit of the apparatus, not shown.

[76] The first angular position sensor 13 is preferably comprised of an encoder.

[77] At a front part of the frame 4 the additional pair of wheels 7 are mounted on a substantially horizontal axle.

[78] Also connected to the front part of the frame 4 is a safety member 14, which extends frontally and acts as a protection barrier for the apparatus in use. The safety member 14 performs the function of cushioning any impacts of the apparatus with the objects present in the work environment.

[79] The safety member 14 is made up, for example, of a cap or a bar exhibiting a curved surface, preferably hemispherical or semi-elliptical, which is connected to the respective ends of the frame 4.

[80] From the guide carriage 3, a support member 15 develops in a longitudinal direction thus forming a support column.

[81] At least one reel 16 of extensible material is mounted on the support column 15, which reel is adapted to be driven in rotation by an actuation unit 17 in order to release, during use, the extensible material to be wrapped around the load 2.

[82] Preferably the material of the reel 16 film is a plastic material.

[83] In particular, the at least one reel 16 is arranged resting on a base 18 which is connected to the support column 15 and is actuated, upon control of suitable actuator means, in translational motion along the aforementioned longitudinal direction.

[84] The actuation unit 17 is mounted on the base 18 and comprises a series of motorized rollers arranged to unwrap the film of extensible material from the at least one reel 16. The actuation unit 17 is not described in further detail as it is known per se.

[85] To the support column 15 a manoeuvring device 19 is connected, which is actuatable by an operator between a first inactive configuration and a second activated configuration. In the activated configuration it is possible to manually control the direction of the apparatus, as better explained herein below.

[86] The manoeuvring device 19 comprises a control lever 20 exhibiting a handle 21 at one end thereof to facilitate the grip of the lever 20.

[87] In particular, the control lever 20 is rotatably actuatable about a first axis of rotation A between the first inactive configuration, wherein it is raised, and the second activated configuration, wherein it is lowered.

[88] Preferably the first axis of rotation A is substantially horizontal.

[89] The control lever 20 is articulated to a guide member 22 which is rotatable, upon control of the lever 20, about a second axis of rotation B, which is substantially perpendicular to the first axis of rotation A.

[90] The guide member 22 is mounted on a stem 23 which rotates about the second axis of rotation B integrally with the guide member 22.

[91] A second angular position sensor 13 is associated with the stem 23 which is able to detect the angular position of the stem 23 and thus of the guide member 22, and to transmit the angular position data of the guide member 22 to the control unit.

[92] Preferably the second angular position sensor 13 is comprised of an encoder.

[93] The data acquired respectively from the first and second angular position sensors 13 are transmitted to the control and processing unit which sends a control signal to the motor unit 9 so that the steering wheels 6 assume an angular position corresponding to the angular position imparted by the operator to the guide member 22 through the control lever 20.

[94] At least one device for acquiring three-dimensional images 24 is associated externally to the guide carriage 3, which is configured to detect three-dimensional images of the to-be- wrapped load 2.

[95] In particular, the device 24 makes it possible to detect three-dimensional images of visible load 2 portions so as to allow the apparatus to be moved around the load 2 and to wrap it with a film of extensible material.

[96] Preferably the device for acquiring three-dimensional images 24 is associated with the support column 15, in particular to an upper portion of the column 15.

[97] The device for acquiring three-dimensional images 24 comprises a stereoscopic camera.

The stereoscopic camera allows to simulate the binocular vision being characteristic of man.

[98] The images acquired by the stereoscopic camera are transmitted to a processing and control unit, which analyses them and based on these images, sends control signals to the motor unit 9.

[99] The processing and control unit comprises an electronic processor or a dedicated electronic card.

[100] The aforementioned image analysis operation is carried out by means of a computer program installed in the electronic computer or in the card.

[101 ] The processing and control units, not visible in the figures, are housed inside the frame 4 of the guide carriage 3, in a special protective casing designed to contain the electronic components.

[102] The guide carriage 3 may be associated with a control panel to allow interaction of the operator with the processing and control unit.

[103] The control panel can comprise means for displaying the information relating to the load 2 and/or information relating to the apparatus.

[104] The control panel can be positioned in a remote control position with respect to the guide carriage 3. [105] The operation of the apparatus for wrapping a load with a film of extensible material is described herein below.

[106] Initially, the apparatus 1 is arranged in the work environment in which the to-be-wrapped load 2 is arranged, in a position suitable for displaying at least one portion of the load 2.

[107] At least one three-dimensional image of a first visible portion of the load 2 is then acquired by means of the device for acquiring three-dimensional images 24 so as to have a view of the visible encumbrance.

[108] The wrapping method provides for moving the apparatus in a predetermined direction around the load 2 based on the at least one three-dimensional image of the first visible portion of the load 2, and, at the same time, to start wrapping the film of extensible material around the load 2.

[109] In particular, the film of extensible material is attached to the load 2 automatically or manually.

[1 10] The wrapping method then provides for detecting at least one three-dimensional image of a further visible portion of the load 2 being consecutive to the first visible portion along the direction of advancement of the apparatus and moving said apparatus around said load 2 in a predetermined direction based on the at least one three-dimensional image of the further visible portion of the load 2.

[1 1 1 ] The apparatus acquires, by means of the device for acquiring three-dimensional images 24, images of successive visible portions of the load 2 and, based on these images, it moves along predetermined directions while continuing at same time to wrap the load 2 with the film of extensible material.

[1 12] The operations of acquiring three-dimensional images of the visible portions of the load 2 and moving the apparatus according to such images are carried out until the wrapping of the film around the load 2 is completed.

[1 13] The acquired three-dimensional images are received by the control and processing unit to control the motor unit 9 of the apparatus.

[1 14] The acquisition of three-dimensional images takes place continuously, allowing to update the direction of movement of the apparatus in real time.

[1 15] In practice, the movement of the apparatus around the load 2 aimed at operating the wrapping, takes place in an "anthropomorphic" manner, that is, by acquiring three- dimensional images of visible portions of the load 2 detected by the device for acquiring three-dimensional images 24 as the apparatus moves around the load 2. Mention can be made of "anthropomorphic manner" since this is comparable to an operator who starts moving around the load 2 based on the three-dimensional image of the portion he/she is viewing, continuing to move and changing direction, if necessary, based on the next visible portion. [1 16] One of the advantages of the method implemented by the apparatus is that it is not necessary to elaborate an overall three-dimensional model of the load 2 to perform load wrapping, since it is sufficient to detect at least one three-dimensional image of the portions of the load 2 being visible as the apparatus moves around the load 2. This ensures that the apparatus moves safely around the load 2, whereby any collisions with any projecting portions of the load itself 2 are avoided.

[1 17] The method also allows to avoid any obstacles which suddenly may appear in the path given that the device for acquiring three-dimensional images 24 acquires three-dimensional images not only of the visible portions of the load 2 but also of the space surrounding these portions.

[1 18] The method also allows to avoid having to calculate a predetermined wrapping path thanks to the continuous acquisition of three-dimensional images of the visible portions of the load 2, which allows the apparatus to navigate autonomously.

[1 19] In the event that setting of a manual control mode is required for the direction of the apparatus, the manoeuvring device is used by having the control lever 20 take over the activated configuration. The guide member 22 is then rotated by the control lever 20 to select the direction of movement of the apparatus.

[120] It is also the object of the present invention a method for controlling the movement of the apparatus by using the device for acquiring three-dimensional images 24.

[121 ] The method for controlling the movement of the apparatus provides for an operator to perform a predetermined movement of the body in the field of view of the device for acquiring three-dimensional images 24. This movement can be, for example, a specific gesture performed with an arm or a hand, preferably facing the device 24.

[122] Next, the method provides for detecting the movement by the device 24 and, subsequently, for activating an operating mode of the apparatus corresponding to the detected movement.

[123] Preferably, the step of activating an operating mode of the apparatus provides to follow the trajectory of the operator who performed the movement.

[124] In particular, the step of following the trajectory of the operator provides for the control unit to send a control signal to the motor unit 9 so that the trajectory of the apparatus substantially corresponds to the trajectory of the operator. In this way the result is obtained of positioning the apparatus in the desired position in an easy and rapid manner.

[125] Alternatively, a further operating mode envisages starting or interrupting a load wrapping cycle 2 upon detection of a specific movement.

[126] The operating modes, which are not limited to the methods described above, are implemented with a respective computer program executed by the processing unit.

[127] it is also the object of the present invention a method for increasing the safety of the apparatus 1 in the operational step which provides for the use of the device for acquiring three-dimensional images 24.

[128] This method comprises the step of detecting, by means of the device for acquiring three- dimensional images 24, a possible obstacle, which may be an object, or a person present in the wrapping path of the load 2.

[129] Following the detection of the obstacle, a control signal is sent to the motor unit 9 to progressively decrease the speed of the apparatus and, finally, to stop the apparatus so as to avoid the impact with the obstacle.

[130] It is to be considered that the safety member 14 contributes to increase the safety of the apparatus as it mitigates any impacts.

[131 ] The method and apparatus for wrapping a load with a film of extensible material according to the present invention achieve the aim of allowing to perform the wrapping operation with an increased degree of autonomy.

[132] In particular, the fact that the method provides for detecting a first three-dimensional image of a visible portion of the load to direct the apparatus around the load and subsequent three- dimensional images of visible portions of the load to adjust the direction as the apparatus moves, achieves the aim of optimally wrapping the film of extensible material around the load.

[133] Moreover, it should be emphasized that the continuous acquisition of three-dimensional images of the visible portions of the load allows to know the profile of the load relative to the visible portion along a direction substantially perpendicular to the lying plane of the load, thus obtaining the effect of following the shape of the load with precision and reliability. In this regard, it is emphasized that there is no need to install spatial references in the environment, such as mechanical constraints, to allow navigation of the apparatus.

[134] Thanks to the stereoscopic camera associated with an upper portion of the support member, the apparatus allows to implement a binocular vision, thereby making it possible to acquire three-dimensional images and to implement an "anthropomorphic" movement around the load to carry out the wrapping. It is also noted that the aforementioned positioning of the camera facilitates the acquisition of images of the visible portions of the load.

[135] In the case of a dynamic load, that is a load that has a shape that can change over time, for example if the load is provided with mobile portions being apt to create protrusions not present in the initial configuration, the method succeeds in carrying out the wrapping in an efficient manner thanks to the fact of detecting three-dimensional images of the visible portions of the load as the apparatus proceeds around the load. These characteristics also allow to wrap a load which exhibits an irregular shape, in particular along a direction substantially orthogonal to the plane whereon the load is lying.

[136] The navigation of the apparatus takes place without the need to store any overall three- dimensional model of the load, nor a predetermined wrapping path based on the model.

[137] The wrapping method being the object of the present invention also achieves the aim of optimizing the time necessary to wrap the film around the load since it is not necessary to perform any detection lap around the load, nor to calculate a path or process a three- dimensional model.

[138] Moreover, the acquisition of three-dimensional images of the visible portions of the load and the area surrounding the portions allows the safety of the apparatus to be increased in that any obstacles can be viewed. According to an aspect of the invention, following the detection of an obstacle, control signals are sent to the motor unit to progressively decrease the speed of the apparatus and to finally stop the apparatus thereby avoiding any impacts with the obstacle.

[139] Finally, it should be emphasized that the method for controlling the movement of the apparatus, being object of the present invention, allows to control the movement of the apparatus simply by performing a predetermined movement in the visual field of the device for acquiring three-dimensional images. The detection of the movement activates a corresponding mode of operation of the apparatus such as, for example, interruption or activation of a wrapping cycle or the tracking mode of the trajectory of the operator who performed the movement. Therefore, it is possible to control the movement of the apparatus quickly and easily.

[140] The apparatus, disclosed by a way of example, is susceptible of several modifications and variations depending on the different requirements.

[141 ] In the practical embodiment of the invention, the materials used, as well as shape and dimensions, may be any one according to requirements.

[142] Where the technical features mentioned in any of the claims are followed by reference numerals, these reference numerals are included to improve the comprehension of the claims only, and consequently they have no limiting effect on the object of each element identified by way of example by these reference numerals.