TECHNICAL FIELD

The invention concerns in general the technical field of material sorting. Espe- cially the invention concerns sensor based material sorting solutions.

BACKGROUND OF THE INVENTION

Material sorting, for example waste sorting, is conventionally done using simple mechanical devices which process material in bulk into different desired categories or "fractions". Examples of such machines are screens, conveyor belts, magnets and air blowers. A shortcoming of these sorting means is that they are inaccurate, large, often consume much energy and are unable to separate many different kinds of fractions and cannot be configured to sort new kinds of fractions.

Another area within the material sorting is so called sensor based material sorting. In sensor based sorting objects are first recognized with sensors and then manipulated with a manipulator, such as an articulated robot arm, gantry-, scara- or another known type of robot, deflecting flap, burst of pressurized air or some other kind of manipulator. The manipulator is used to deposit the objects in receptacles, also known as "bins", based on the readings from the sensors. Sensor based sorting is able to sort objects to a large number of different fractions. A shortcoming of sensor based sorting compared to conventional bulk methods is the lower scalability of the system capacity. Increasing the amount of material fed into the system makes it harder for sensor systems to tell apart different objects, as the objects may cover each other partly or in whole, and it also makes objects obstructed by other objects unavailable for the manipulators to manipulate. This problem is especially difficult if the objects form a disorganized pile, rather than being fed to the system in a controllable manner. Another scalability issue with sensor based sorting with manipulators is that for sorting many different kinds of fractions, the manipulator must be able to reach the receptacles, for each fraction. In practice this limits the amount of different fractions for many manipulators to the number of receptacles installable near the manipulator. Thus, there is need to develop the material sorting solutions so that the mentioned shortcomings of existing systems may be mitigated and the utilization of sensor based material sorting can be improved.

SUMMARY OF THE INVENTION An objective of the invention is to present a material sorting unit, a system and a method for sorting objects in a material feed in an improved manner. Another objective of the invention is that the material sorting unit, the system and the method comprise a manipulator for distributing the input material feed so that the latter parts of the material sorting unit and the system receive more infor- mation on objects in the material feed.

The objects of the invention are reached by a material sorting unit, a system and a method as defined by the respective independent claims.

According to a first aspect, a material sorting unit is provided wherein the material sorting unit comprises at least one first manipulator for singularizing at least one object at least partly from at least one other object from an input material feed; at least one sensor for obtaining information on at least one object, when the at least one object is taken to an operational area of the sensor, at least one second manipulator; and at least one computing unit for analyzing the obtained information on the at least one object by the at least one sensor and generating a control signal for the at least one second manipulator if the obtained information meets criterion predefined for the at least one second manipulator in order to sort the at least one object from the material feed.

The material sorting unit may further comprise at least one sensor for obtaining information on the input material feed, the obtained information may be config- ured to be analyzed by at least one computing unit in order to derive at least one control signal for the at least one first manipulator. The at least one computing unit may be configured to derive at least one control signal for the at least one second manipulator at least partly on a basis of at least one of the following: obtained information by at least one sensor, at least one derived control signal for the at least one first manipulator. The at least one first manipulator may be at least one of the following: a robot arm, gantry-type robot, a scara robot, a cable actuated robot where the tool is suspended on cables, a vibrating table. Moreover, the at least one sensor may be at least one of the following: material detector, spectrometer, 3d scanner, metal detectors, mag- netic field sensor, radioactivity sensor, weight sensor, strain gauge, weight sensor, height sensor, pressure sensor, camera.

The first manipulator may be configured to manipulate the objects from the input material feed by arranging them in at least one queue for the at least one sensor.

According to a second aspect, a system for sorting material in a material feed is provided wherein the system comprises at least two material sorting units, wherein each material sorting unit comprising at least one first manipulator for singularizing at least one object at least partly from at least one other object from an input material feed fed to each of the material sorting unit; at least one sensor for obtaining information on at least one object when the at least one object is taken to an operational area of the sensor; and at least one second manipulator, and wherein the system further comprises at least one computing unit for analyzing the obtained information on the at least one object by the at least one sensor from each of the material sorting units and generating a control signal for each of the at least one second manipulator in each of the material sorting units if the obtained information from the at least one sensor of each of the at least two material sorting units meets criterion predefined for the at least one second manipulator in the corresponding material sorting unit in order to sort the at least one object from the material feed.

At least one of the first manipulators in the at least two material sorting units may comprise at least one sensor for obtaining information on the input material feed, the obtained information is configured to be analyzed by at least one computing unit in order to derive at least one control signal for the at least one first manipulator.

According to a third aspect, a method for sorting at least one object in a material feed is provided wherein the method comprises inputting a material feed comprising at least one object in a material sorting unit; singularizing at least one object from the input material feed by manipulating it with at least one first manipulator belonging the to the material sorting unit; and delivering the at least one manipulated object for a manipulation by at least one second manipulator belonging to the material sorting unit, the manipulation of the at least one second manipulator is performed in response to an analysis of a sensor data obtained with at least one sensor of the second manipulator. The exemplary embodiments of the invention presented in this patent application are not to be interpreted to pose limitations to the applicability of the appended claims. The verb "to comprise" is used in this patent application as an open limitation that does not exclude the existence of also un-recited features. The features recited in depending claims are mutually freely combinable unless otherwise explicitly stated.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS Fig. 1 illustrates a first example of the present invention, fig. 2 illustrates another example of the invention, fig. 3 illustrates an example of a system according to the invention, and fig. 4 illustrates an example of a method according to the invention. DETAILED DESCRIPTION

The present invention relates to an idea wherein material sorting is arranged so that prior to taking a portion of the material to be sorted in an operational distance of at least one sensor at least one manipulator is arranged to manipulate an input material feed so that an effectiveness of the at least one sensor, and the at least one further manipulator, can be optimized. For example, in some implementation of the invention the effectiveness of the at least one sensor can be optimized, when the material to be sorted is arranged to be evenly distributed over a detection area of the at least one sensor. Then, the sensor may provide the most accurate detection information on the content of the material to be sorted for the rest of the system, such as for an analysis unit. The at least one manipulator arranged to operate prior to the at least one sen- sor may be selected according to expected content of the material to be analyzed and sorted. Fig. 1 illustrates an example of the present invention disclosing the fundamental idea of the invention. The present invention is based on an idea in which at least one manipulator 1 10 is arranged to receive input material feed to be sorted and manipulate the input material feed in such a way that at least one sen- sor 120 may receive more information on the manipulated material feed than could directly be gained from the input material feed. The information detected by the at least one sensor 120 is conveyed to a computing unit 140 for analysis. The analysis may comprise, but is not limited to, determination of material type and on the basis of the information the computing unit 140 is configured to deliver control signals to further manipulators 150A, 150B arranged within operational distance to the conveyor belt 130. The manipulators 150A, 150B are configured to, in response to control signals from the computing unit 140, to manipulate one or multiple type of materials traveling on the conveyor belt 130 in such a way that they are sorted to receptacles 160A, 160B dedicated to a corresponding material type. The solution according to present invention may comprise one or more first manipulators 1 10 of similar or different types, one or more sensors 120 of similar or different types, one or more second manipulators 150A, 150B of similar or different types, one or more receptacles 160A, 160B of similar or different types. Moreover, the conveying of the ma- nipulated material feed to be sorted may be arranged with one or more separate conveyor belts 130, e.g. arranged in parallel, or with conveyor belt 130 elements coupled in series to each other or in any combination of these two. The analysis of input from the one or more sensors 120 and determination and delivery of control signals to different entities may be arranged by one or multiple computing units 140 coupled together to operate as a distributed computing system.

According to an example of the present invention the at least one first manipulator 1 10 is arranged to receive input material feed and manipulate the input material feed in such a way that at least one sensor 120 may receive more in- formation on the manipulated material feed than could directly be gained from the input material feed and as a result at least one second manipulator may optimally manipulate the manipulated material feed based on the sensor data from the at least one sensor 120. The delivery of the material under an operational distance of the first manipulator may be arranged with a conveyor belt, which is either separate to the conveyor belt 130 or the same conveyor belt 130. If the input material feed is delivered to the first manipulator by means of a conveyor belt, the first manipulator comprises means for manipulating the input material feed in such a manner that the at least one sensor may receive more information from the manipulated material feed than could directly be gained from the input material feed and the at least one second manipulator may optimally manipulate the material feed based on the sensor data. For example, the first manipulator 1 10 may be a robot, such as an articulated robot arm, a gantry robot, a scara robot, a cable actuated robot where the tool is suspended on cables, or another known type of robot, which is configured to pick up pre-defined objects from the input material feed and proceed according to pre-defined instructions with the picked up objects. In one implementation the first manipulator may be arranged to pick up pre-defined objects of certain sizes, like too large or too small, and remove those from the input material feed, which is configured to be conveyed under an operational distance of the at least one sensor 120 and at least one second manipulator 150A, 150B. Al- ternatively or in addition, the first manipulator 1 10 may be configured to pick up certain objects and place them into input feeding system, such as a conveyor belt, for the at least one second manipulator 150A, 150B. The advantage of such an arrangement is that objects within the material feed input to the operational area of the at least one sensor 120 are manipulated in such a manner that the at least one sensor 120 may receive more information on each of the objects going through the operational area of the sensor than could directly be gained from the input material feed, as the objects are singularized from other objects. In other words, the objects do not cover each other over an acceptable level. In some other implementation of the invention the first manipulator 1 10 may be a vibrating table, which is arranged to controllably vibrate at least in response to input of material on it. The vibrations cause a spread of the input material within the table, which spread material may be input to the at least one second manipulator 150A, 150B via e.g. a conveyor belt 130. The vibrating table may be positioned within the input end of the conveyor belt 130 so that it may deliver the spread material optimally, such as constantly, on the conveyor belt 130. For example, the vibrating table may e.g. be slanted in relation to the conveyor belt 130 in order to arrange the delivery of the material through vibrating the table.

The mentioned at least one first manipulator 1 10 may be equipped with its own set of sensors comprising one or more individual sensor elements in order to obtain necessary information on the input material feed for the operation of the at least one first manipulator 1 10. The information obtained from the at least one sensor is configured to be analyzed in a computing unit and control signals may be derived for the first manipulator as an output of the analysis.

The aim of the operation by the at least one first manipulator 1 10, which may comprise one or more sensors for obtaining information for the at least one first manipulator 1 10, is that the material feed to the system may be arranged in such form that that the at least one sensor 120 may receive as much information from the manipulated material feed as possible and the at least one second manipulator may optimally manipulate the manipulated material feed based on the sensor data.

In some further implementation at least part of the sensor data from the sensor providing information for the operation of the first manipulator 1 10 may be delivered to the computing unit 140, which may be arranged to combine the sensor data for the first manipulator with the sensor data from the at least one sensor 120. From the combined sensor data it is possible to derive control signals for the at least one second manipulator 150A, 150B. Furthermore, it is possible to arrange so that information on the derived control signals for the first manipulator and/or operational information on the at least one first manipulator may be delivered to the computing unit 140, which information may be utilized in a derivation of the control signals for the at least one second manipulator 150A, 150B. For example, if the first manipulator 1 10 is configured to singularize the input material feed by arranging pieces of the input material feed into one or more queues based e.g. on material type, information on the material in the queues may be delivered in the computing unit 140, which in- formation may be utilized in the derivation of control signals for the at least one second manipulator 150A, 150B. Naturally, the same information may be preprogrammed in the computing unit 140. The arrangement as described may provide tools for optimizing e.g. the sensor types needed in implementing the system according to the present invention. Sensors for the at least one first and second manipulators are arranged to monitor and obtain information on objects in material feed passing an operational area of the sensors. The sensors are advantageously selected optimally in order to determine a necessary amount of information on objects passing it. As said any sensor set applied in the solution according to the invention may comprise one or more sensor of similar or different types. Examples of appli- cable sensors for obtaining information may be, but are not limited to, one or more material detectors, one or more spectrometers, one or more 3d scanners, one or more metal detectors, one or more magnetic field sensors, one or more radioactivity sensors, one or more weight sensors, one or more strain gauges, one or more weight sensors, one or more height sensors, one or more pressure sensors, one or more cameras and so on. In some advantageous example of the invention when the first manipulator is a controllable robot arm, a gantry-type robot, a scara robot or a cable actuated robot where the tool is suspended on cables, applicable sensor 215 may be at least one of the follow- ing: one or more material detectors, one or more spectrometers, one or more 3d scanners, one or more metal detectors, one or more magnetic field sensors, one or more radioactivity sensors, one or more weight sensors, one or more strain gauges. Correspondingly, in some other advantageous example of the invention when the first manipulator is a vibrating table an applicable sensor may be at least one of the following: one or more weight sensors, one or more height sensors, one or more pressure sensors, one or more 3d scanners, one or more cameras. For sake of clarity it is to be noted that any combination of the mentioned sensors is also possible within the inventive idea of the present invention. The at least one second manipulator 150A, 150B may be any type of manipulator applicable to the need. A criterion in the selection of the at least one second manipulator may be the type of material to be manipulated with the at least one second manipulator 150A, 150B and the target fractions the material is to be sorted into. Examples of the at least one second manipulator 150A, 150B may be, but are not limited to, articulated robot arm, gantry-type robot, scara-type robot, a cable actuated robot where the tool is suspended on cables, deflecting flap or burst of pressurized air, and so on.

As already mentioned the object of an operation of the at least one first manipulator is that 1 10 at least part of the input material feed may be arranged so that at least one sensor 120 may receive more information on the manipulated material feed than from the original material feed and at least one second manipulator may best manipulate the manipulated material feed based on the sensor data. In some implementation of the invention the first manipulator is configured to singularize the input material feed, or at least one object therein, in queues for the at least one sensor 120 and thus for the latter manipulators. The queuing may be configured to be performed so that multiple queues are arranged in one conveyor belt according to some predetermined criteria. The criteria may be, but is not limited to, type of material, shape of object, an identifier determined from the objects and so on. The latter manipulators are configured, in any manner, to take care of the manipulated material i.e. objects in the queues. Fig. 2 illustrates another example, how the solution can be arranged. Herein is disclosed one first manipulator comprising a conveyor belt 210 into which a material feed is input. The first manipulator in this example further comprises a controllable robot arm 220. The operation of the robot arm may be controlled at least partly on a basis of some sensor data obtained by monitor- ing the input material feed in the first conveyor belt 210 with at least one sensor 215. The first manipulator is configured to sort the input material feed into to corresponding modules by some predetermined criteria. The corresponding modules both comprise a conveyor belt 130A, 130B, sensor unit 120A, 120B, manipulator 150A, 150B and receptacles 160A, 160B. The aim of each of the modules is to sort, e.g. independently from the other, to sort the material i.e. objects received from the first manipulator. The whole system may be controlled with a computing unit 140, which, in this example, is arranged to communicate with each element in the solution in a wireless manner. In Fig. 2 it is illustrated some objects in an input material feed, which is further manipulated at least partly in the conveyor belts 130A, 130B (symbols square, triangle and circle are used).

As can be seen from Figs. 1 and 2 there are many ways to implement the solution according to the inventive idea of the present invention. The main idea is that there is some first manipulating unit or device, which is configured to ma- nipulate the input material feed in such a manner that the rest of the system, i.e. one or more sensors and manipulators, may efficiently sort out material feed input to them. In some implementation the first manipulator may be some mechanical device, such as a material spreader, but in preferred embodiments of the invention the first manipulator is a unit operating in an active manner fol- lowing some predetermined scheme in manipulating the material.

A further aspect of the invention is that the material sorting by the at least one second manipulator 150A, 150B may result that the material on the conveyor belt 130 is again in non-optimal form for further manipulators. This is because the operation of the first second manipulator may mix up the objects within the material feed causing problems in sorting. According to a further example of the present invention it is possible to combine multiple material sorting units as described. Fig. 3 illustrates an example of such an arrangement in which three material sorting units 301 , 303, 305 are coupled to each other in series manner. Each of the material sorting units may comprise at least one first manipulator for singularizing at least one object at least partly from at least one other object from an input material feed fed to each of the material sorting unit, at least one sensor 120 for obtaining information on at least one object when the at least one object is taken to an operational area of the sensor 120 and at least one second manipulator 150, 150A, 150B. Further, the system may comprise at least one computing unit 140, which is configured to analyze the ob- tained information on the at least one object by the at least one sensor 120 from each of the material sorting units and to generate a control signal for each of the at least one second manipulator 150, 150A, 1 50B in each of the material sorting units if the obtained information from the at least one sensor meets criterion predefined for the corresponding at least one second manipulator 150, 150A, 150B in order to sort the at least one object from the material feed. In the example of Fig. 3 each of the material sorting units 301 , 303, 305 are illustrated as being the same for the sake of clarity. However, each of the material sorting units within the system may differ from each other or be any combination of any separate units. In Fig. 3 it is depicted that the system comprises a common computing unit 140, but it is possible to arrange separate computing units for each of the material sorting units to perform the operations as described. The separate computing units 140 may be arranged to communicate with each other. Moreover, a possible implementation of the solution according to the present invention is that a first computing unit is arranged to control the first manipulator 1 10 and a second computing unit is arranged to control one or more material sorting units. The system may comprise two or more material sorting units as described according to the need.

The invention also relates to a method for sorting objects from a material feed. An example of the method is depicted in Fig. 4. The method comprises input- ting 410 a material feed comprising at least one object in a material sorting unit. In the next step, the at least one object is singularized 420 from the input material feed by manipulating it with at least one first manipulator belonging to the material sorting unit. The singularized object by manipulation with the at least one first manipulator is delivered 430 for manipulation by at least one second manipulator belonging to the material sorting unit wherein the manipulation of the at least one second manipulator is performed in response to an analysis of a sensor data obtained with at least one sensor of the second manipulator.

Generally speaking, the sensor data obtained from sensors dedicated to first or second manipulator is configured to be analyzed with a computing unit. The computing unit is further configured to derive control signals to corresponding manipulators, and/or for any other elements belonging to the system. The solution according to the invention may be implemented so that there is one central computing unit to perform the mentioned tasks for the whole system or each element or module may comprise its own computing unit, which computing units may be arranged to communicate with each other. It is also possible to implement any sub-combination of these two alternatives, as already disclosed in the description. The control signals determined by the one or more computing units comprise information to control the operation of the solution as a whole or in part. For example, the control signals may comprise, but are not limited to, position information on one or more objects to be manipulated, such as picked up, and position information on locations in where the object in question shall be positioned through manipulation. Moreover, the control signals may comprise any additional information relating to the object itself, such as a type of the object, or e.g. locations of the receptacles, and instructions to con- trol the operation of manipulators in question and so on.

The present invention is especially applicable for waste sorting purposes, as there exist multiple types of objects to be sorted. In order to improve efficiency in the waste sorting the present invention may be applied. However, the invention is not limited to the waste sorting only, but may be applied in any environ- ment wherein material sorting is needed.

Above it is mainly described that the material is input to the first manipulator as a material feed. The material feed shall also cover, but is not limited to, inputting of the material as a disorganized pile. The input material in any form may be manipulated as described herein. In the description it is used a term 'to singularize' or any derivative therefrom for a purpose in indicating that the at least one first manipulator is configured to itemize at least part of the material for achieving the objects as described. The singularization may comprise, but is not limited to, separating the objects from each other either totally or at least in part so that the at least one sensor 120 is able to obtain a necessary amount of information from an object in question so that the at least one computing unit may establish control signals for the latter at least one manipulator as regards the object in question. At least some advantages gained from the singularization are that the at least one sensor 120 may obtain more information on the manipulated material feed than directly from the input material feed and the operation of the at least one second manipulator is also more efficient with the singularized material.

Some advantageous embodiments according to the invention were described above. The invention is not limited to the embodiments described. The in- ventive idea can be applied in numerous ways within the scope defined by the claims attached hereto.