Automation method for setting the payload of a collaborative robot

Abstract

This provides an automated method for setting the payload of a collaborative robot. [Solution] A method and system for automatically setting the payload weight value of a collaborative robot, wherein one or more objects are lifted by the robot's gripping unit, the weight of the objects is automatically determined by force sensors and used as the payload, and the payload value is automatically adjusted when any of the objects are lowered. If all objects are known to have the same weight, only one weight measurement is required, and objects of different weights can be handled by measuring the weight of each object. The system automatically handles payload adjustment without requiring manual adjustment or custom programming. The robot uses the payload weight value when detecting externally applied forces indicating contact with a worker or other objects, and to ensure that the acceleration of the payload does not exceed the upper limit of the gripping force or the load limit of the robot's joints.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit of the priority date of U.S. Provisional Patent Application No. 63 / 715,043, titled "Automated Method for Setting Payload of a Collaborative Robot", filed on November 1, 2024.

[0002] This disclosure generally relates to the field of controlling industrial robots, and more specifically, to a method for automatically setting the weight value of the payload of a collaborative robot, where one or more objects are lifted by the gripping part of the robot, the weight of the object is automatically determined by a force sensor and that weight is used for the payload, and the payload value is automatically adjusted when any object is lowered and released.

Background Art

[0003] It is well known to use industrial robots to perform a wide range of manufacturing, assembly, and material movement operations. Many of these operations are performed by articulated robots, such as 5 - axis or 6 - axis robots with servo motors at each rotating joint. The control of such robots is provided in real - time, the operation program is divided into small motion increments, and the robot controller executes calculations for real - time feedback control to calculate the input commands for the joint motors that move the tool tip point at the end of the robot's arm along a defined trajectory.

[0004] One common type of robot operation is material movement, which involves moving a load or workpiece from a starting position to a destination position. A specific application of this type is when the robot is equipped with a vacuum gripping tool and the robot lifts a load (e.g., a box) and moves it to a defined position. This type of robot operation is commonly used for depalletizing or palletizing (i.e., moving boxes from a pallet to a conveyor or vice versa).

[0005] In the types of operations described above, it is necessary to know the "payload," i.e., the weight of the object being moved by the robotic arm. The payload is typically considered to include a gripping unit (often a vacuum gripping unit with considerable weight) and the box being carried by the gripping unit at any given time. The payload weight value is used to calculate the trajectory of the robotic arm tip and the corresponding velocity and acceleration, which are necessary to keep the robot's joint loads within specified limits and to prevent the box from detaching from the vacuum gripping unit.

[0006] In certain applications, the use of collaborative robots is required; these are robots designed to be used alongside human workers within a work area. Collaborative robots include control functions to prevent strong contact between the robot or its payload and human workers. In collaborative robot applications, the payload weight is used, in addition to the trajectory calculation purposes described above, to establish control parameters for detecting contact with obstacles within the work area. [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Various methods have been used to determine the payload weight of a robot. In the simplest case, the robot moves only one box at a time, and all boxes have the same weight, which is known. In this case, the payload weight is simply the weight of the gripping unit if the gripping unit is not carrying a box, or the weight of the gripping unit plus the known weight of the box if the gripping unit is carrying a box.

[0008] However, most real-world applications are more complex, such as having boxes of varying sizes and weights on a single pallet, requiring the robot to lift multiple boxes simultaneously, lowering and releasing some boxes in one location and others in another. In such applications, determining the payload weight can be complex and time-consuming.

[0009] One known technique for determining the weight of a payload is to simply measure the weight of all boxes being carried after each gripping or release operation. Weight measurement can be performed by force sensors mounted on the robot arm near the vacuum gripping section. The drawback of this technique is that the robot must stop after each gripping or release operation, and then a certain amount of time is required for weight measurement. These measurement delays significantly reduce the productivity of the robot performing the load transfer.

[0010] Even when the weight of the boxes is known (whether all boxes have the same weight or boxes of various known weights), most palletizing / depalletizing operations require flexibility in gripping and releasing boxes in different numbers and combinations, depending on the specific pallet configuration. For example, in one operation, the robot may need to grip three boxes of different weights and lower them one by one to different locations, and in the next operation, the robot may need to grip four boxes of the same weight and lower and release them in quantities of two, one, and one. Each of these different operation combinations requires a specific payload plan, and each payload plan specifies the weight values ​​of the payload at each of the multiple steps of the operation. This can lead to a rapid increase in payload plans, making them difficult to track and requiring complex custom programming for integration with robotic control systems.

[0011] In light of the above circumstances, there is a need for an improved method for setting payload weight values ​​that does not require defining payload plans or custom programming, and does not cause unnecessary delays in load weighing. [Means for solving the problem]

[0012] This disclosure describes a method and system for automatically setting the payload weight value of a collaborative robot, where one or more objects are lifted by the robot's gripping unit, the weight of the objects is automatically determined by force sensors and used as the payload, and the payload value is automatically adjusted when any of the objects are lowered and released. If all objects are known to have the same weight, only one weight measurement is required; objects of different weights can be handled by measuring the weight of each object. The system automatically handles payload compensation without requiring payload planning or custom programming. The robot uses the payload weight value when detecting externally applied forces indicating contact with a worker or other objects, and to ensure that the payload acceleration does not exceed the gripping force capacity or the load limits of the robot's joints.

[0013] Additional features of the systems and methods of this disclosure will become apparent from the following description and the attached claims, in conjunction with the attached drawings. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 shows an industrial robot equipped with a vacuum gripping tool, with a load attached to the vacuum gripping section and being moved by the robot, as an example of an application that may benefit from the techniques of the present disclosure. [Figure 2] Figure 2 includes illustrations of many identical box pallets and box pallets of different sizes and weights, further illustrating examples of applications that may benefit from the techniques of this disclosure. [Figure 3] Figure 3 is a flowchart of an existing technique, as known in the art, for setting the weight value of a payload using payload planning in robotic palletizing or depalletizing operations. [Figure 4] Figure 4 is a flowchart illustrating a method for automatically setting the payload weight value of a robot that picks and places a single box, according to an embodiment of the present disclosure. [Figure 5]Figure 5 is a flowchart illustrating a method for automatically setting the payload weight value of a robot that picks and places multiple boxes, according to an embodiment of the present disclosure. [Modes for carrying out the invention]

[0015] The following discussion of embodiments of this disclosure directed toward automated payload setting for collaborative robots is purely illustrative and is not intended to limit the disclosed devices and techniques or their applications or uses.

[0016] Industrial robots are used in a variety of manufacturing, assembly, and material handling tasks. In some applications, robots are used to move workpieces or loads from one location to another. A specific example of robotic load handling is known as depalletizing, where boxes are removed from a pallet and moved to a destination location, such as a conveyor belt. The reverse operation, picking boxes from a conveyor belt and placing each box in a specific location on a pallet, is known as palletizing and is equally commonly employed.

[0017] Figure 1 shows an industrial robot 100 equipped with a vacuum gripper 120, with a load 130 attached to the vacuum gripper 120 and moved by the robot 100, as an example of an application that may benefit from the techniques of the present disclosure. The robot 100 includes an articulated robotic arm having a plurality of links 110, the links 110 being connected to each other by rotary joints driven by servo motors, as is known to those skilled in the art. The vacuum gripper 120 is a tool used by the robot 100, and the vacuum gripper 120 is connected to an outer arm link or wrist joint of the robot 100. The vacuum gripper 120 is a commonly used tool when the load 130 is a box, or a plurality of boxes, as described below.

[0018] The robot 100 communicates with the control device 140 in a manner known in the art, and the control device 140 provides the robot 100 with joint motion commands, causing the robot 100 to have the vacuum gripping unit 120 grasp the load 130 and move it to a target position, and then, by motion commands, the robot 100 moves the gripping unit 120 to a destination position where the load 130 is placed and released. When multiple boxes are grasped, they may be placed in different locations or all in the same location.

[0019] The load sensor 150 can be mounted on the robot 100, such as between the outer arm link 110 and the vacuum gripping unit 120, as shown in the figure. Other locations suitable for a particular robot model can be used for the load sensor 150, including integrating the load sensor into one of the arm links 110 so that the sensor is not visible from the outside. The load sensor 150 provides measurements to the control unit 140. In a typical palletizing / depalletizing operation, under static conditions, the force or load value measured by the sensor 150 is the weight of the gripping unit 120 and the box attached to it (i.e., the load 130).

[0020] Figure 2 includes illustrations of a pallet 200 containing many identical boxes and a pallet 220 containing boxes of different sizes and weights, further illustrating examples of applications that may benefit from the techniques of this disclosure. Pallet 200 contains multiple boxes 210, each identical. The weight of each box 210 may or may not be known in advance. It should be noted that each layer of pallet 200 contains two boxes in different orientations, which is fairly common. The vacuum gripping unit on the robotic arm can be rotated to lift two boxes aligned in one orientation, or to lift two boxes in one orientation and a third box in the other orientation, to give a few examples.

[0021] Pallet 220 includes a plurality of boxes of three different sizes and shapes, including a plurality of each of box 230, box 240, and box 250. Pallet 220 is depicted in separate layers each containing only boxes of one particular size, although this is not necessarily the case. In a mixed-size pallet, different load sizes may be arranged in the same layer and there may actually be no parallel layers. Further, a mixed-size pallet may include boxes of the same size but different weights.

[0022] From FIG. 2, the depalletizing operation can be easily visualized. Here, a pallet such as pallet 200 or pallet 220 is presented to a robot, and the robot grips the boxes from the pallet and moves them to another location. As described above, the techniques of the present disclosure described below are also applicable to the palletizing operation, where boxes or other loads are taken from one location such as a truck or conveyor and placed in a specific location and orientation on a pallet being constructed.

[0023] Some of the palletizing operations and depalletizing operations as described above are performed by an articulated robot attached to a mobile base. This allows the robot to be moved to a desired location to perform the palletizing operation or depalletizing operation near a truck, loading dock, conveyor, etc. Some of these types of operations are performed using a collaborative robot in the presence of a human operator.

[0024] Accurately setting the weight value of the payload for the material transfer operation by a robot is important for multiple reasons. First, the payload value is used in the calculation of the robot trajectory and acceleration when moving an object from one place to another. In the case of a heavy payload, it may be necessary to reduce the acceleration during material transfer to prevent exceeding the gripping capacity of the vacuum gripper or the load limit of the robot joints. Additionally, the weight value of the payload is used in the motion control of a collaborative robot to detect contact between the robot or its payload and any obstacles, including human operators. If the weight value of the payload is too high, the collaborative robot may not stop as desired in the event of an accidental contact. If the weight value of the payload is too low, the robot controller may interpret the normal operating load as an indicator of contact and trigger a robot stop command. This requires the operator to manually clear the obstacle to resume the operation, resulting in unnecessary robot downtime.

[0025] Material transfer operations by robots, such as palletizing and depalletizing, are often performed on the floors of warehouses and factories where various items are handled. In other words, the robot may be used to depalletize several pallets of boxes from a truck where all the boxes are the same size and weight, and then the robot may be used to build pallets from multiple boxes of different sizes and weights arriving on a conveyor. The flexibility of this type of work has, in the past, required defining and programming multiple payload plans for the robot, and the appropriate payload plan is selected when each specific operation is initiated.

[0026] A payload plan is a document or data table that defines the weight value of the payload for a specific combination of loads carried by the vacuum gripper.

[0027] Figure 3 is a flowchart of existing technology for setting payload weight values ​​using payload planning in robotic palletizing or depalletizing operations, as is known in the art. In box 310, a robot equipped with a vacuum gripper lifts multiple boxes from a pallet, conveyor, or other source. In this example, all boxes are the same size and have a known weight. In box 320, the first step of payload planning selection is performed based on the number of boxes lifted. In this example, three boxes have been picked, so there are three optional paths for payload planning selection depending on the plan for lowering and releasing the boxes.

[0028] In box 330, the plan is to unload one box (for example, onto a pallet or conveyor). Therefore, in box 332, a payload plan identified as #3 is selected, which sets the payload based on the number of boxes and resets the payload based on the number of new boxes, which is one less after being unloaded and released.

[0029] In box 340, the plan is to unload two boxes. Therefore, in box 342, a payload plan identified as #2 is selected, which sets the payload based on the number of boxes and resets the payload based on the new number of boxes, which is two fewer after being unloaded and released.

[0030] In box 350, the plan is to unload three boxes. Therefore, in box 352, a payload plan identified as #1 is selected, which sets the payload based on the number of boxes and resets the payload based on the new number of boxes, which is three fewer after being unloaded and released.

[0031] In box 360, one or more boxes are lowered and released at a designated location. The process then moves to determination rhombus 370, where it is determined whether the lowering and releasing operation that was just completed was the last lowering and releasing operation of the current cycle (i.e., whether the gripping unit is currently empty). If the gripping unit is not empty, the process returns to box 320, where a new current number of boxes is set, and a new payload plan is selected from one of three paths based on the planned next lowering quantity.

[0032] In the determination diamond 370, if the last lowering value is true (i.e., the gripping part is empty), the process moves to box 380, and the next cycle begins with the robot lifting multiple boxes in box 310.

[0033] Even in the simple example in Figure 3, it is clear that a payload plan must be developed and custom robot logic programmed to accommodate all possible combinations of lifting, lowering, and releasing sequences for each box. A typical real-world palletizing / depalletizing operation using a modern industrial robot may require handling 20-30 different types of boxes, each with varying sizes and weights. Simultaneously, the vacuum gripper can grip up to 10 boxes at a time, which can be lowered and released individually or in groups. The weight of these loads and the number of gripping / lowering options create a vast number of possible payload combinations, sometimes exceeding 200. Using existing methods, a payload plan must be defined for each of these possible payloads, and custom robot programming must be created to integrate the payload plan into the robot operation as shown in Figure 3. Managing all this complexity is labor-intensive and error-prone.

[0034] Another technique has been developed for setting the payload weight value without requiring complex payload planning and programming. This technique involves measuring the payload weight after each pick or place operation and setting the payload weight value accordingly. While this technique is simple and flexible, it adds considerable delay to pick-and-place operations.

[0035] Consider an example where a robot picks up four boxes and lowers and releases them one at a time. In this example, the robot needs to measure the weight of the boxes four times: 1) Measure the weight of the four boxes as it lifts them. 2) Lower one box and measure the weight of the remaining three boxes. 3) Lower one box and measure the weight of the remaining two boxes. 4) Lower one box and measure the weight of the remaining one box.

[0036] As shown in Figure 1, a typical industrial robot equipped with a vacuum gripper and load sensor requires approximately 1.8 seconds to accurately record weight values. When weight measurement is required after every pick-and-place process, this measurement delay can add a significant and undesirable amount of time. In the example described above, with four measurement steps, the measurement delay amounts to 7.2 seconds (4 × 1.8) per cycle. Considering that this type of robot can currently process up to 10 boxes per pick cycle, the measurement delay could reach as high as 18 seconds. These delays represent a serious negative impact on the robot's productivity.

[0037] The technologies described herein have been developed to overcome the limitations of existing technologies, including the need for complex payload planning and integrated programming, as well as the delays associated with measuring payload weight at every step. These technologies are described below.

[0038] The payload compensation method of this disclosure incorporates several key concepts that improve robot productivity and reduce complexity. First, the disclosed method eliminates the definition and custom programming of payload planning by simply using either a fully loaded or empty gripping payload, with the fully loaded gripping payload being adjustable during the load pick / place cycle. Second, the disclosed method includes a user-configurable setting that specifies whether the pick / place operation is moving boxes of consistent weight or boxes of different weights. Furthermore, the disclosed method provides automated payload weighing by a load sensor on the robot, but measures the payload weight only when necessary, thereby eliminating many unnecessary measurement delays. Automated weighing on demand also eliminates the need for external weighing devices such as scales, along with the associated creation of a payload plan based on externally measured weights.

[0039] Figure 4 is a flowchart 400 of a method for automatically setting the payload weight value of a robot picking and placing a single box according to an embodiment of the present disclosure. In box 410, the robot picks up a single box from a conveyor, container, or pallet. In determination rhombus 420, it is determined whether the boxes being handled have a consistent weight (all the same, as in pallet 200 in Figure 2) or not (at least two different weights, as in pallet 220 in Figure 2). Specifying the weight of a consistent or inconsistent box is a user-configurable setting that can be selected on the user interface screen of the robot control device (or corresponding remote control device, teach pendant, etc.).

[0040] If all boxes have a consistent weight, the determination diamond 430 determines whether the currently picked box is the first box in the pick / place operation. For example, when picking the first box from pallet 200, the determination diamond 430 will be "yes" for the first box. Subsequently, for the rest of pallet 200 and the other pallets in its composition, the determination diamond 430 will be "no".

[0041] In determination diamond 430, if the determination is yes and it is the first box, in box 440, the robot measures the weight of the box using the mounted load sensor (e.g., load sensor 150 in Figure 1). In box 450, the "full-load gripping payload plan" is set by adding the weight of the box measured in box 440 to the known empty gripping payload. The full-load gripping payload plan is used by the robot for the current pick / place cycle. In box 452, depending on the requirements of the palletizing / depalletizing operation, the box is lowered by the robot to a designated location (inside the container, on a pallet, on a conveyor, etc.). After lowering and releasing the only box, in box 460, the payload plan is switched to an empty gripping payload plan, which is predefined based on the weight of the gripping part only. The process then loops back to box 410, where the robot picks another box.

[0042] For each subsequent box picked, as long as it is specified that the box weight is consistent, the process moves directly from determination rhombus 430 to box 450, and since the box weight is known to be the same, the same value as before is used to select a fully loaded gripping payload plan. Thus, the box weight measurement at box 440 is skipped, thereby avoiding unnecessary measurement delays.

[0043] If the box weights are inconsistent, the process moves from the determination rhombus 420 to box 470, where the robot measures the box weight using its onboard load sensor. In box 480, the full-load gripping payload plan is set by adding the weight of the box measured in box 470 to the known empty gripping payload. The full-load gripping payload plan is used by the robot for the current pick / place cycle. In box 482, the box is lowered to the location specified by the robot. After lowering and releasing the only box, in box 490, the payload plan is switched to the empty gripping payload plan. The process then loops back to box 410, where the robot picks up another box. For each subsequent box to be lifted, as long as the box weight is specified as inconsistent, the process moves from the determination rhombus 420 to box 470, where the new box weight is measured.

[0044] Continuing to refer to Figure 4, if we follow the left side of the flowchart (constant box weight), the disclosed method first provides automatic measurement of the box weight, and then skips weight measurement in all subsequent cycles, resulting in significant time savings.

[0045] If following the right side of flowchart 400 (non-constant box weight), the user simply needs to specify an empty gripping payload to start the production operation. In contrast, using existing technology, a payload plan must be defined for each possible box weight, these payload plans must be integrated with the control software using custom programming, and the correct payload plan must be selected for each individual box to be lifted by the robot.

[0046] From the above description, it is clear that the automated payload compensation method disclosed in this disclosure offers advantages over existing methods for both constant and non-constant box weight operations.

[0047] Figure 5 is a flowchart 500 of a method for automatically setting the payload weight value of a robot that picks and places multiple boxes, according to an embodiment of the present disclosure. In box 510, the robot lifts multiple boxes (from a conveyor, container, or pallet, etc.). The number of boxes lifted in box 510 is known.

[0048] In the determination rhombus 520, it is determined whether the boxes being handled have a constant weight (all the same, such as pallet 200 in Figure 2) or not (at least two different weights, such as pallet 220 in Figure 2). The specification of the box weights for matching or not matching is a user-configurable setting that can be selected on the user interface screen on the robot control device (or the corresponding remote control device, teach pendant, etc.).

[0049] If all boxes have a constant weight, in box 530, the robot measures the weight of all boxes using an onboard load sensor (e.g., load sensor 150 in Figure 1). In box 540, the weight of each individual box is calculated from the known empty weight of the gripping unit, the measured weight of all boxes from box 530, and the known number of boxes. This is done by subtracting the empty gripping unit weight from the fully loaded gripping unit weight and dividing the difference by the number of boxes.

[0050] In box 542, the "Fully Loaded Gripping Payload Plan" is set using the known empty gripping payload and the weight of the currently gripped box (equal to the weight measured in box 530 during the initial pass). The Fully Loaded Gripping Payload Plan is used by the robot for the current pick / place cycle until part of the payload is unloaded. In box 544, depending on the requirements of the palletizing / depalletizing operation, a known number of boxes are unloaded by the robot to designated locations, such as inside a container, on a pallet, on a conveyor, etc. After one or more boxes have been unloaded, determination diamond 550 determines whether the last box has been unloaded. If so, the payload plan in box 560 is switched to the empty gripping payload plan, and the process loops back to box 510 where the robot picks up another set of boxes.

[0051] In the determination diamond 550, if the gripping section is not empty, the process returns to box 540 to recalculate the weight of the boxes currently being gripped. This is done by determining the number of boxes remaining attached to the gripping section (original quantity minus the quantity unloaded), multiplying this by the known weight per box, and adding this to the gripping section weight. In box 542, the "full" gripping payload plan is adjusted to the weight of the boxes currently being gripped and the gripping section weight, and this payload value is used until more boxes are unloaded. After more boxes have been unloaded in box 544, the determination diamond 550 is again checked to determine whether the gripping section is empty, and the process continues in this manner.

[0052] The process on the left side of Figure 5 allows for the gradual unloading of a large payload of boxes (e.g., 8-10 boxes) without remeasuring the weight of the remaining boxes or defining a payload plan (e.g., 2 here, 3 there, etc.). All of this is handled automatically as described above. In fact, as long as the box weights are specified to be constant, measurements in box 530 can be skipped after the first measurement, because the total box weight can be determined from the known weight per box and the number of boxes held in box 510.

[0053] If the box has a non-constant weight, the process moves from the determination rhombus 520 to box 570, where the robot measures the weight of the box using the mounted load sensor. In box 572, the full-load gripping payload plan is set using the known empty gripping payload and the weight of the box measured in box 570. Of course, if the measured weight in box 570 includes the gripping part along with the box, that measured weight is used for the full-load gripping payload plan. The full-load gripping payload plan is used by the robot for the current pick / place cycle.

[0054] In box 574, a known number of boxes are lowered by the robot to a designated location. After lowering one or more boxes, determination diamond 580 determines whether the last box has been lowered. If so, the payload plan in box 590 is switched to an empty grasp payload plan, and the process loops back to box 510 where the robot lifts another set of boxes.

[0055] In the determination diamond 580, if the gripping section is not empty, the process returns to box 570 to measure the weight of the currently gripped box. In box 572, the "full" gripping payload plan is adjusted to include the weight of the gripping section plus the weight of the currently gripped box, and this payload value is used until more boxes are unloaded. After more boxes have been unloaded in box 574, the determination diamond 580 is again checked to determine whether the gripping section is empty, and the process continues in this manner.

[0056] If following the right side of flowchart 500 (non-constant box weight), the user simply needs to specify an empty gripping payload to start production. In contrast, using existing technology requires defining payload plans (which can be hundreds) for each possible combination of box weights, integrating those payload plans with control software using custom programming, and selecting the correct payload plan for each combination of boxes to be lifted by the robot.

[0057] From the explanation in Figure 5, it is clear that the advantages of the disclosed automated payload compensation method are applicable to picking operations involving many boxes, for both constant and non-constant box weights.

[0058] The automated payload compensation technology disclosed herein can be advantageously applied to many types of robotic pick-and-place operations. These operations include palletizing and depalletizing (discussed in detail above), conveyor picking (lifting boxes of unknown weight from one conveyor and placing them on another conveyor, pallet, or other location), container picking (grabbing all objects of the same type within a container and moving them to another location), and "individual picking" (grabbing different types of objects within a container individually and moving them to another location). Furthermore, the disclosed technology is applicable to both collaborative and non-collaborative industrial robots.

[0059] Throughout the preceding description, various computers and control devices are described and suggested. It should be understood that the software applications and modules of these computers and control devices run on one or more electronic computing devices having processors and memory modules. In particular, this includes one or more processors in the robot control device 140 described above. Specifically, the processor in the control device 140 is configured to perform the automatic payload compensation technique described above.

[0060] In the above description, exemplary views and embodiments of methods and systems for automatic payload compensation have been discussed, but those skilled in the art will recognize the modifications, changes, additions and secondary combinations related thereto. Accordingly, the following appended claims and any claims introduced thereto are intended to be interpreted as encompassing all such modifications, changes, additions and secondary combinations that fall within their true technical idea and technical scope.

Claims

1. A method for setting the payload weight value of an industrial robot, To provide multiple objects that can be grasped, The robot grasps a predetermined number of objects using a gripping part attached to it, The total weight of the predetermined number of objects is measured using the robot or a load sensor attached to the gripping part. Using the total weight of the predetermined number of objects, the weight value of the payload is set, including the known weight value of the empty gripping part. When all the gripped objects have the same weight, the total weight is divided by the number to determine the weight of each object, the gripping part is moved to the target position, a portion of the predetermined number of objects is lowered, and the weight of the payload is reduced by the amount obtained by multiplying the number of lowered objects by the weight of each object. A method comprising: moving the gripping part to a target position if the gripped objects do not all have the same weight, lowering a predetermined number of objects, measuring the new weight of the reduced number of objects using a load sensor, and setting the weight value of the payload using the new weight.

2. The method according to claim 1, further comprising lowering the next portion of the predetermined quantity of objects until the gripping portion is empty, resetting the weight value of the payload so that at that point the weight value of the payload is set to the weight value of the empty gripping portion.

3. The method according to claim 1, wherein, when the predetermined quantity is 1 and all grippable objects have the same weight, one object is grasped, the weight of only the first object is measured, the weight value of the payload is set using the weight of the first object including the known weight value of the empty gripping portion, one object is lowered, and the process of grasping and lowering additional objects is repeated without measuring the weight of each of the additional objects.

4. The method according to claim 1, wherein, if the predetermined quantity is 1 and all grippable objects do not have the same weight, the method includes gripping one object, measuring the weight of one object, setting the weight value of the payload using the weight of one object including a known weight value of the empty gripping portion, lowering one object, and repeating the process of gripping and lowering additional objects, each of which is weighed.

5. The method according to claim 1, wherein the weight value of the payload is used when calculating the trajectory for the movement of the object by the robot, and the trajectory includes the spatial path of the gripping part and the velocity and acceleration profiles along the spatial path.

6. The method according to claim 5, wherein calculating the trajectory includes calculating the joint load of the robot and the force between the gripping part and the object based on the trajectory and the weight value of the payload, and if the joint load of the robot or the force between the gripping part and the object exceeds a corresponding predetermined limit, the trajectory is recalculated until the joint load of the robot and the force between the gripping part and the object no longer exceed the limits.

7. The method according to claim 5, wherein the robot is a collaborative robot configured to allow a human worker to work in the vicinity of the robot, and the weight value of the payload is also used to establish a threshold for external forces on the robot that would cause the robot to stop working.

8. The method according to claim 1, wherein the robot performs a palletizing or depalletizing operation by grasping and moving an object.

9. The method according to claim 1, wherein the gripping portion is a vacuum gripping portion comprising a plurality of individually and selectively activatable suction elements, each object is gripped by activating one or more of the suction elements and released by deactivating one or more of the suction elements.

10. The method according to claim 1, wherein a configuration parameter indicating whether all grippable objects have the same weight is defined prior to gripping a predetermined number of objects.

11. A method for setting the payload weight value of an industrial robot, The present invention provides multiple objects that can be grasped, and defines a configuration parameter indicating whether all the graspable objects have the same weight. The method involves gripping a predetermined number of objects with a gripping unit attached to a robot, wherein the gripping unit is a vacuum gripping unit including a plurality of individually and selectively operable suction elements, and each object is gripped by activating one or more of the suction elements. The total weight of the predetermined number of objects is measured using the robot or a load sensor attached to the gripping part. The weight value of the payload is set using the total weight of the predetermined number of objects, including the known weight value of the empty gripping part. When all the gripped objects have the same weight, the weight of each object is determined by dividing the total weight by the number of objects, the gripping part is moved to the target position, a portion of the predetermined number of objects is lowered, and the weight of the payload is reduced by an amount obtained by multiplying the number of lowered objects by the weight of each object. If the gripped objects do not all have the same weight, the gripping part is moved to the target position, a portion of the predetermined number of objects is lowered, the new weight of the reduced number of objects is measured using a load sensor, and the weight value of the payload is set using the new weight. The system includes lowering the next portion of the predetermined quantity of objects until the gripping portion is empty, thereby resetting the weight value of the payload, and at that point the weight value of the payload is set to the weight value of the empty gripping portion. A method wherein the weight value of the payload is used to calculate a trajectory used to move the gripping part to a target position, the trajectory comprising the spatial path of the gripping part and profiles of velocity and acceleration along the spatial path.

12. The method according to claim 11, wherein, when the predetermined quantity is 1, one object is grasped, the weight of the one object is measured, the weight value of the payload is set using the weight of the one object, including the known weight value of the empty grasping part, the one object is lowered, the grasping and lowering of additional objects is repeated, and if not all graspable objects have the same weight, only the weight of each additional object is measured.

13. The method according to claim 11, wherein calculating the trajectory includes calculating the joint load of the robot and the force between the gripping part and the object based on the trajectory and the weight value of the payload, and if the joint load of the robot or the force between the gripping part and the object exceeds a corresponding predetermined limit, the trajectory is recalculated until the joint load of the robot and the force between the gripping part and the object no longer exceed the limit.

14. The method according to claim 13, wherein the robot is a collaborative robot configured to allow a human worker to work in the vicinity of the robot, and the weight value of the payload is also used to establish a threshold for external forces on the robot that would cause the robot to stop working.

15. A robot pick-and-place system with an automatic payload compensation function, An industrial robot to which a gripping part is attached, and a load sensor connected to the robot and / or the gripping part, A robot control device that communicates with the robot, the gripping unit, and the load sensor, comprising a robot control device configured to perform the following steps, wherein the steps are: To grasp a predetermined number of objects from a plurality of objects that can be grasped, Using the load sensor, the total weight of the predetermined number of objects is measured, The weight value of the payload is set using the total weight of the predetermined number of objects, including the known weight value of the empty gripping part. When all the gripped objects have the same weight, the weight of each object is determined by dividing the total weight by the number of objects, the gripping part is moved to the target position, a portion of the predetermined number of objects is lowered, and the weight of the payload is reduced by an amount obtained by multiplying the number of lowered objects by the weight of each object. A system comprising: moving the gripping unit to a target position if the gripped objects do not all have the same weight; lowering a predetermined number of objects; measuring the new weight of the reduced number of objects using the load sensor; and setting the payload weight value using the new weight.

16. The system according to claim 15, wherein the control device is further configured to lower the next portion of the predetermined quantity of objects until the gripping portion is empty, thereby resetting the weight value of the payload, and at that point the weight value of the payload is set to the weight value of the empty gripping portion.

17. The system according to claim 15, wherein the control device is further configured to grasp one object, measure the weight of only the first object, set the payload weight value using the weight of the first object, including the known weight value of the empty gripping part, lower one object, and repeat the grasping and lowering of additional objects without measuring the weight of each of the additional objects.

18. The system according to claim 15, wherein the control device is further configured to grasp one object, measure the weight of one object, set the payload weight value using the weight of that one object, including a known weight value of the empty gripping part, and repeat grasping and lowering additional objects, including lowering the one object and measuring the weight of each of the additional objects, when the predetermined quantity is 1 and all grippable objects do not have the same weight.

19. The system according to claim 15, wherein the weight value of the payload is used by the control device to calculate a trajectory for the movement of the object by the robot, and the trajectory includes the spatial path of the gripping part and the velocity and acceleration profiles along the spatial path.

20. The system according to claim 19, wherein calculating the trajectory includes calculating the joint load of the robot and the force between the gripping part and the object based on the trajectory and the weight value of the payload, and if the joint load of the robot or the force between the gripping part and the object exceeds a corresponding predetermined limit, the trajectory is recalculated until the joint load of the robot and the force between the gripping part and the object no longer exceed the limit.

21. The system according to claim 20, wherein the robot is a collaborative robot configured in which a human worker works in the vicinity of the robot, and the weight value of the payload is also used by the control device to establish a threshold of external force on the robot that causes the robot to stop moving.

22. The system according to claim 15, wherein the robot performs palletizing or depalletizing operations by grasping and moving an object.

23. The system according to claim 15, wherein the gripping portion is a vacuum gripping portion comprising a plurality of individually and selectively activatable suction elements, each object is gripped by activating one or more of the suction elements and released by deactivating one or more of the suction elements.

24. The system according to claim 15, wherein a configuration parameter indicating whether all grippable objects have the same weight is defined prior to gripping a predetermined number of objects.

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