Method for feeding workpieces into a production process system by means of a feeding system, and feeding system
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- VOLKSWAGEN AG
- Filing Date
- 2024-07-18
- Publication Date
- 2026-06-17
Smart Images
Figure EP2024070381_13022025_PF_FP_ABST
Abstract
Description
[0001] Description
[0002] Method for feeding workpieces into a production process plant by means of a feeding system and feeding system
[0003] The present invention relates to a method for feeding workpieces into a production process plant and to a feeding plant designed to carry out such a method.
[0004] The automated and orderly feeding of randomly delivered workpieces into a production process, also known as "bin picking", has so far resulted in an undesirably long cycle time and requires a particularly large amount of space in a production facility. Therefore, a common approach is currently to avoid the bin picking principle. To achieve this, however, it is necessary to deliver the workpieces to be fed into the production process in an at least pre-ordered or partially ordered state, for example stacked, grouped, pre-centered, etc., which is particularly complex. This is demonstrated, for example, by EP 2 604 383 A1, which proposes using a robot to feed workpieces arranged in workpiece bundles to a processing machine. The workpiece bundle is gripped by the robot and placed in a pre-centering device.From there, the robot removes one of the workpieces from the container and feeds it to the processing machine. Due to the pre-centering device, such a system requires a particularly large amount of space. Furthermore, feeding the workpieces takes a comparatively long time, measured from the moment the workpiece container is picked up, because the robot first picks up the workpiece container, moves it, places it in the pre-centering device, and then releases it. Only then does the robot pick up one of the workpieces from the workpiece container, move it, and finally feed it to the processing machine.
[0005] For removing one of a randomly delivered part / article from a container, DE 103 19253 A1 discloses a method for the correct positioning of parts that are gripped from a container by a robot. A sensor, in particular a camera, is arranged on the robot. When the part is gripped by the robot, this sensor determines a positional deviation of the part position from a standard position. A movement of the robot is corrected accordingly. JP 2011 000669 A2 proposes a method for aligning an article. An article is gripped by a first arm of a two-arm robot. If the article is twisted, a marker of the article is then detected by a marker detection sensor of the first arm. In this case, the article is transferred to a second arm of the robot, which places it in a predetermined orientation.However, these conventional approaches require complex programming of the robot and complex control.
[0006] The object of the present invention is to create a solution to be able to feed workpieces delivered in an unordered manner into a production process plant particularly efficiently.
[0007] This problem is solved by the subject matter of the independent claims. Further possible embodiments of the invention are disclosed in the subclaims, the description, and the figures. Features, advantages, and possible embodiments presented in the description for one of the subject matter of the independent claims are to be regarded, across categories and embodiments, at least analogously as features, advantages, and possible embodiments of the respective subject matter of the other independent claims, as well as any possible combination of the subject matter of the independent claims, optionally in conjunction with one or more of the subclaims.
[0008] The invention proposes a method for feeding workpieces into a production process plant by means of a feeding plant, as well as a feeding plant. The feeding plant is set up to carry out steps of the method according to the invention and for this purpose has, among other things, two separate robots of the same or different design. The respective robot is, for example, an articulated arm robot, a gantry robot, etc. The feeding plant further has a control device which is configured to control the robots according to the method. In particular, the control device is a computer, and the method is a computer-implemented method. In this case, the invention includes a computer program and a computer-readable storage medium on which the computer program is stored. The computer program comprises instructions which, when executed by the computer orthe control device causes it / these to control the robots according to the steps explained in more detail below.
[0009] A prerequisite for the process is that the workpieces are within the operating range of the feeding system's robots. Although the process is of course also applicable if the workpieces to be fed into the production process system are delivered in an orderly manner into the operating range of the robots, the main focus here is on workpieces that are initially located in a box or other container in a disordered manner. This means that the workpieces are, for example, bulk materials.
[0010] In the method, one of the workpieces and its position in the box is then detected by means of a position detection sensor in the feeding system. In other words, the position detection sensor detects how and in which spatial arrangement the workpiece is located in the box and, in particular, which workpiece it is. For this purpose, the position detection sensor can have an imaging sensor, for example a camera sensor or the like, in particular a sensor that provides a three-dimensional image of the workpiece in the box, such as a stereo camera, a laser sensor, etc. and / or a distance measuring sensor, for example an ultrasonic sensor. The detected image and / or distance data are evaluated by means of the feeding system, for example by means of an image processing unit in the feeding system. The detected workpiece is then coupled to a handling effector of a first of the robots.The handling effector comprises, for example, a vacuum generator, an electromagnet, and / or a finger gripper, etc., and is designed to be coupled to the workpiece in such a way that the workpiece can be moved by the robot. Simply put, the workpiece is picked up by the handling effector. The workpiece, coupled to the handling effector in this way, is then moved out of the box by the first robot and—also by the first robot or while the workpiece is being moved out—moved into a position control position. The position control position is characterized by the fact that the workpiece can be grasped or detected particularly efficiently by the position detection sensor. The position detection sensor then detects a coupling position of the workpiece in relation to the handling effector of the first robot.
[0011] In other words, the position detection sensor determines the position of the workpiece relative to the handling effector with which it is coupled. Based on this detected coupling position, a workpiece positioning action is then carried out by the feed system. The workpiece positioning action ensures that the workpiece can be placed at a specified feed point of the production process system and there in a specified feed position. After the workpiece positioning action has been carried out, the workpiece is placed on the feed point by one of the robots, thereby bringing the workpiece into the specified feed position.
[0012] Thanks to the process and feeding system, pre-arranging the workpieces to be fed into the production process is no longer necessary. This saves time and labor during the infeed of the workpieces as well as at a point upstream of the feeding. Feeding and infeeding is highly flexible, as the bin-picking principle can be used without any loss of efficiency or accuracy. Furthermore, the process and feeding system are particularly space-saving, as there is no need for resources for pre-arranging, pre-sorting, or turning / flipping the workpiece to be fed. A particularly high cycle time and high output also characterize the process. Furthermore, a particularly low error rate due to the use of position detection sensors, which can be used to perform 2D or 3D position corrections if necessary, is noteworthy.The use of this process is not limited to automotive manufacturing, but can be used in all conceivable production processes in the manufacturing industry, as well as for the pure separation and / or sorting of parts of any type. In general, the process enables industrial-grade provision of unordered workpieces within cycle time and with industrial-grade technical availability.
[0013] In a further possible embodiment, executing the workpiece positioning action comprises providing a confirmation signal if the position detection sensor system has detected that the coupling position of the workpiece in relation to the handling effector of the first robot allows the workpiece to be placed on the feed point and in the predetermined feed position without prior correction of the coupling position. This means that the workpiece has been picked up by the first robot or its handling effector in such a way that correction of the coupling position can be omitted and the workpiece can still be efficiently moved to the feed point and thus into the predetermined feed position. The workpiece is then placed accordingly by the first robot depending on the confirmation signal, i.e., on the feed point and thus into the predetermined feed position. In this way, the placement of the workpiece on the feed point is particularly fast.In addition, the second robot of the feeding system may not be involved in picking up and placing the workpiece, which is why it can remove another workpiece at least from the box at the same time or at a different time. If no correction of the coupling position is necessary for this additional workpiece, the second robot places the additional workpiece on the feeding point or on a different feeding point in the same way as the first robot. In general and across all embodiments, the terms “first robot” and “second robot” do not indicate a hierarchy between the robots. The robots can operate in collaboration with one another or - as mentioned - independently of one another or on an equal footing. Referring to them as the first or second robot merely serves to easily distinguish the robots of the feeding system.According to a possible further development, executing the workpiece positioning action comprises coupling the workpiece to a handling effector of the second robot and subsequently decoupling the workpiece from the handling effector of the first robot if the position detection sensor system has detected that the coupling position of the workpiece relative to the handling effector of the first robot would prevent the workpiece from being placed on the feed point and into the specified feed position without prior correction of the coupling position. Therefore, a correction of the coupling position is necessary in order to be able to efficiently move the workpiece to the feed point and thus into the specified feed position.The workpiece is coupled to the handling effector of the second robot in such a way that it is in a coupling position with respect to the handling effector of the second robot that allows the workpiece to be placed on the feed point and in the specified feed position without further correction of the coupling position. The workpiece is then moved or placed on the feed point and thus in the specified feed position by means of the first or the second robot. In this case, the two robots of the feeding system collaborate with each other, i.e., they are both involved in picking up and placing the workpiece. In this way, the workpiece is initially aligned particularly efficiently and precisely with regard to its position and orientation in space by means of the feeding system, in particular its robots. This makes placing the workpiece on the feed point and arranging it in the specified feed position even easier.
[0014] If a correction of the coupling position is required according to the above description, a further possible embodiment provides that the placement of the workpiece comprises coupling the workpiece to the handling effector of the first robot and then decoupling the workpiece from the handling effector of the second robot if the position detection sensor system has detected that the coupling position of the workpiece relative to the handling effector of the first robot allows the workpiece to be placed on the feed point and in the specified feed position without further correction of the coupling position. In simple terms, the workpiece is returned to the first robot.In this way, the coupling position of the workpiece relative to the handling effector of the first robot is efficiently corrected, since when the workpiece is returned, the handling effector of the first robot and the workpiece are coupled to one another in such a way that the workpiece can be placed on the feed point and in the specified feed position without further correction of the coupling position. Alternatively or additionally, after the workpiece has been returned to the first robot, the coupling position of the workpiece relative to the first robot can be re-evaluated using the position detection sensor system. The workpiece is then subsequently placed accordingly by the first robot. In this way, the second robot is advantageously only involved in picking up and placing the workpiece to the extent that it is used to correct the coupling position of the workpiece relative to the handling effector of the first robot.This allows the second robot to be used to remove another workpiece while the first robot deposits it. Specifically, the robots swap roles for the next workpiece. This contributes to a desirable short cycle time for feeding the workpieces.
[0015] Again in connection with the required correction of the coupling position according to the above description, a further possible embodiment provides for the workpiece to be deposited directly by the second robot if the position detection sensor system has detected that the workpiece is coupled to the handling effector of the first robot via a support side of the workpiece, which is intended to rest directly on the workpiece in the feed position at the feed point. Thus, the workpiece is efficiently turned by the collaboration of the two robots, with the turning of the workpiece and its coupling position correction taking place in a single operation. This further shortens the cycle time for removing and depositing the workpiece.
[0016] For the entire process and its possible embodiments, the following applies in each case in a possible further development: after the workpiece has been coupled to the handling effector of the first robot, it is always coupled to one of the robots until it is placed at the feed point and is not placed down in between. Any necessary position and / or orientation corrections, as well as turning of the workpiece, are carried out exclusively by handling by the first and / or second robot. This particularly takes into account the idea of a particularly short cycle time for removing and placing the workpiece. Furthermore, intermediate storage, etc., can be dispensed with.
[0017] According to a possible further development of the feeding system, the position detection sensor system has a first position detection sensor which is arranged on the first robot, in particular on its handling effector. In other words, one of the two robots of the feeding system carries the first position detection sensor, since no hierarchy between the robots can be derived from the designations “first robot” and “second robot” (see above). Alternatively or additionally, the position detection sensor system has a second position detection sensor which is arranged on the second or other robot, in particular on its handling effector. This makes the feeding system particularly space-saving, since no separate area needs to be provided for arranging the position detection sensor system. In addition, the respective position detection sensor is advantageously always particularly close to the item to be removed orworkpiece to be handled, which makes data acquired by the corresponding position detection sensor particularly reliable.
[0018] In another possible embodiment of the feeding system, the position detection sensor system includes a third position detection sensor, which is located away from the robots and directed toward the robots' operating area. The third position detection sensor is arranged, in particular, above the box in which the workpieces are arranged in a random manner. This allows for a particularly simple robot design and increases the flexibility of the feeding system. The first, second, and / or third position detection sensors are configured individually or in groups to execute the corresponding steps of the method.
[0019] Further features of the invention can be derived from the following description of the figures and from the drawings. The features and combinations of features mentioned above in the description, as well as the features and combinations of features shown below in the description of the figures and / or in the figures alone, can be used not only in the respective combinations specified, but also in other combinations or on their own, without departing from the scope of the invention.
[0020] The drawing shows, in the single figure (Fig. 1), a schematic view of a feeding system 1 having two separate robots 2, 3, wherein the feeding system 1 is designed to feed workpieces 4 into a production process system (not shown) by placing the workpiece 4 at a feed point of the production process system by means of the feeding system 1. For this purpose, the feeding system 1 is configured to carry out a method for feeding workpieces 4 into the production process system. Identical or functionally equivalent elements are provided with the same reference numerals in Fig. 1. In the present example, the robots 2, 3 are of identical design, each being an articulated-arm robot. The robot 2 is referred to as the first robot 2, and the robot 3 accordingly as the second robot 3, merely by way of example.
[0021] Area a) of Fig. 1 shows an initial situation from which the method begins. The workpieces 4 are arranged in a random manner, for example as bulk material, in a container 5. It can also be seen that the robots 2, 3 each have a handling effector 6, 7 and a position detection sensor 8, 9. The handling effectors 6, 7 and the position detection sensors 8, 9 are arranged on a respective end member 10, 11 of the robots 2, 3 or form the corresponding end member 10, 11. According to the present example, the first handling effector 6 and the second handling effector 7 are designed as a respective switchable electromagnet. The feeding system 1 also has a control device 12, which is in particular a computer controller for controlling the robots 2, 3 and other components of the feeding system 1, i.e. a computer.The position detection sensors 8, 9 are part of a position detection sensor system of the feeding system 1, wherein the position detection sensor system in the present case has a third position detection sensor 13 which is arranged away from the robots and is directed towards an action area of the robots 2, 3.
[0022] In the method, one of the workpieces 4 is detected by means of the position detection sensor system, in this case by means of the first position detection sensor 8, and in this process, a positional position of the corresponding workpiece 4 in relation to the container 5 is detected. In particular, the type of workpiece 4 is detected. For this purpose, the feeding system 1, in particular its control device 12, has an image processing unit (which can be a software module) to which data determined by the position detection sensor system is provided. In this case, this is image data, since the position detection sensors 8, 9, 13 in the present example are designed as camera sensors, in particular as 3D or stereo cameras or as laser sensors, etc.The captured image data is evaluated by the image processing unit of the feed system 1, whereupon the detected workpiece 4 is coupled to the first handling effector 6 of the first robot 2. The workpiece 4 coupled to the first handling effector 6 is moved out of the container 5 by the first robot 2 and into a position control position. This is shown in area b) of Fig. 1. In the present case, the first robot 2 presents the workpiece 4 removed from the container 5 to the second robot 3, in particular to its second position detection sensor 9. By means of the position detection sensor system—here by means of the second position detection sensor 9—a coupling position of the workpiece 4 in relation to the first handling effector 6 of the first robot 2 is then determined or detected.Based on this detected coupling position, a workpiece positioning action is then carried out by means of the feed system 1, by means of which it is ensured in the method that the workpiece 4 can be placed on the specified feed point and there in a specified feed position. After carrying out the workpiece positioning action, the workpiece 4 is placed on the feed point by means of one of the robots 2, 3, whereby the workpiece 4 is brought into the specified feed position. It is particularly advantageous in the method if - as in the present case - the workpiece 4, after it has been coupled to the handling effector 6 of the first robot 2, is always coupled to one of the robots 2, 3 until it is placed on the feed point and is not placed down in between.Executing the workpiece positioning action includes, for example, providing a confirmation signal if the position detection sensor system has detected that the coupling position of the workpiece 4 relative to the handling effector 6 of the first robot 2 allows the workpiece 4 to be placed on the feed point and in the specified feed position without prior correction of the coupling position. This means that the workpiece 4 has been picked up by the first robot 2 or its handling effector 6 in such a way that correction of the coupling position can be omitted and the workpiece 4 can still be efficiently moved to the feed point and thus into the specified feed position. The workpiece is then placed accordingly by the first robot 2 depending on the confirmation signal, i.e., on the feed point and thus into the specified feed position.In this case, the second robot 3 is not involved in picking up and placing the workpiece 4, which is why it can simultaneously or staggeredly remove another workpiece 4 at least from the container 5. If no correction of the coupling position is required for this additional workpiece 4 either, the second robot 3 places the additional workpiece 4 on the feed point or on another feed point, analogously to the first robot 2.
[0023] Alternatively, or with a different workpiece and as shown in areas c) and d) of Fig. 1, executing the workpiece positioning action comprises coupling the corresponding workpiece 4 to the second handling effector 7 of the second robot 3 and then decoupling said workpiece 4 from the first handling effector 6 if it has been detected by the position detection sensor system that the coupling position of the workpiece 4 relative to the first handling effector 6 would prevent the workpiece 4 from being placed on the feed point and in the predetermined feed position without prior correction of the coupling position. Therefore, a correction of the coupling position is necessary in order to be able to move the workpiece 4 efficiently to the feed point and thereby into the predetermined feed position.The workpiece 4 is coupled to the handling effector 7 of the second robot 3 in such a way that it is arranged in a coupling position relative to the second handling effector 7, which allows the workpiece 4 to be placed on the feed point and in the specified feed position without further correction of the coupling position. The workpiece 4 is then moved or placed onto the feed point and thus into the specified feed position by means of the first robot 2 or the second robot 3. The two robots 2, 3 of the feeding system 1 collaborate with each other in this case, i.e., they are both involved in picking up and placing the workpiece 4.
[0024] For example, the workpiece 4 is deposited by the first robot 2, for which the workpiece 4 is returned to the first handling effector 6. If the workpiece 4 has been positionally corrected by the second handling effector 7, the first robot 2 takes over again by re-coupling the workpiece 4 to the first handling effector 6 and then decoupling the workpiece 4 from the second handling effector 7. This occurs when the position detection sensor system - here the second position detection sensor 9 of the second robot 3 - detects after the workpiece 4 has been returned that the coupling position of the workpiece 4 in relation to the handling effector 6 of the first robot 2 now allows the workpiece 4 to be deposited on the feed point and in the specified feed position without further correction of the coupling position.In particular, when returning the workpiece 4, the first handling effector 6 and the workpiece 4 are coupled together in such a way that the workpiece 4 can be placed on the feed point and in the specified feed position without further correction of the coupling position. The workpiece is then subsequently placed accordingly by the first robot 2.
[0025] Alternatively, or in the case of a different workpiece 4, it is placed directly by the second robot 3. If the position detection sensor detects that the workpiece 4 is coupled to the first handling effector 6 via its support side 4a, which is intended to rest directly on the first handling effector 6 in the feed position at the feed point, the workpiece 4 is turned by being transferred to the second robot 3. The second robot then places the workpiece 4 on the feed point as intended, with the support side 4a and the feed point facing each other.
[0026] The process and the feeding system 1 each show a possibility of how workpieces delivered in an unordered manner can be fed particularly efficiently into a production process plant.
[0027] List of reference symbols
[0028] Feeding system
[0029] robot
[0030] robot
[0031] Workpiece a support side
[0032] container
[0033] Handling effector
[0034] Handling effector
[0035] Position detection sensor
[0036] Position detection sensor 0 End link 1 End link 2 Control device 3 Position detection sensor
Claims
Patent claims 1. A method for feeding workpieces (4) into a production process plant by means of a feeding system (1) which has two separate robots (2, 3), wherein the workpieces (4) are initially arranged in a container (5) in an unordered manner and the method comprises the following steps: - Detection of one of the workpieces (4) and its position in the container (5) by means of a position detection sensor of the feeding system (1), - coupling the detected workpiece (4) with a handling effector (6) of the first robot (2), - moving the workpiece (4) out of the container (5) and positioning the workpiece (4) coupled to the handling effector (6) into a position control position by means of the first robot (6), - by means of the position detection sensor system: detecting a coupling position of the workpiece (4) in relation to the handling effector (6) of the first robot (2), - carrying out a workpiece positioning action based on the detected coupling position, which ensures that the workpiece (4) can be placed on a predetermined feed point of the production process system and there in a predetermined feed position, - after the workpiece positioning action: placing the workpiece (4) on the feed point by means of one of the robots (2, 3), whereby the workpiece (4) is brought into the specified feed position.
2. Method according to claim 1, characterized in that the execution of the workpiece positioning action comprises providing a confirmation signal if it has been recognized by means of the position detection sensor system that the coupling position of the workpiece (4) in relation to the handling effector (6) of the first robot (2) allows the workpiece (4) to be placed on the feed point and in the predetermined feed position without prior correction of the coupling position, and the workpiece (4) is placed accordingly by means of the first robot (2) in dependence on the confirmation signal.
3. Method according to claim 1 or 2, characterized in that the execution of the workpiece positioning action comprises coupling the workpiece (4) to a handling effector (7) of the second robot (3) and then decoupling the workpiece (4) from the handling effector (6) of the first robot (2) if it was detected by means of the position detection sensor system that the coupling position of the workpiece (4) in relation to the handling effector (6) of the first robot (2) would prevent the workpiece (4) from being placed on the feed point and in the predetermined feed position without prior correction of the coupling position, wherein the workpiece (4) is coupled to the handling effector (7) of the second robot (3) in such a way that it is in a coupling position in relation to the handling effector (7) of the second robot (3) which allows the workpiece (4) to be placed on the feed point and in the predetermined feed position without further correction of the coupling position allowed,and the workpiece (4) is deposited accordingly by means of one of the robots (2, 3)., 4. Method according to claim 3, characterized in that the depositing of the workpiece (4) comprises coupling the workpiece (4) to the handling effector (6) of the first robot (2) and then decoupling the workpiece (4) from the handling effector (7) of the second robot (3) if it has been detected by means of the position detection sensor system that the coupling position of the workpiece (4) in relation to the handling effector (6) of the first robot (2) allows the workpiece (4) to be deposited on the feed point and in the predetermined feed position without further correction of the coupling position, and the workpiece (4) is deposited accordingly by means of the first robot (2).
5. Method according to claim 3 or 4, characterized in that the workpiece (4) is deposited directly by means of the second robot (3) when it has been detected by means of the position detection sensor system that the workpiece (4) is coupled to the handling effector (6) of the first robot (2) via a support side (4a) of the workpiece (4), which in the feed position at the feed point is to lie directly on the workpiece (4).
6. Method according to one of the preceding claims, characterized in that the workpiece (4), after it has been coupled to the handling effector (6) of the first robot (2), is always coupled to one of the robots (2, 3) until it is placed on the feed point and is not placed down in between.
7. Feeding system (1) with two separate robots (2, 3), a position detection sensor system and a control device (12) which is configured to control the robots (2, 3) according to the method designed according to one of the preceding claims.
8. Feeding system (1) according to claim 7, characterized in that the position detection sensor system comprises: - a first position detection sensor (8) arranged on the first robot (2), in particular on its handling effector (6), and / or - a second position detection sensor (9) arranged on the second robot (3), on its handling effector (7).
9. Feeding system (1) according to claim 7 or 8, characterized in that the position detection sensor system has a third position detection sensor (13) which is arranged away from the robots (2, 3) and is directed towards an action area of the robots (2, 3).