Method and system for setting payload weight value of industrial robot

Abstract

A method, system for setting a payload weight value for an industrial robot in which one or more objects are picked up by a robot gripper, the weight of the object is automatically determined by a force sensor and the weight is used for the payload, and the payload value is automatically adjusted when any object is unloaded. When the weights of all objects are known to be the same, only one time of weight measurement is needed, and objects of different weights can be processed through the weight measurement performed for each object. The system automatically processes payload adjustments without the need for manual adjustments or custom programming. The robot uses a payload weight value upon detection of any externally applied force indicative of contact with an operator or other object, and is also used to ensure that payload acceleration does not exceed a gripping force capability or robot joint load limit.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 715,043, entitled “Automated Method to Set Payload of Collaborative Robot,” filed November 1, 2024. Technical Field

[0003] This application relates to a method and system for setting the payload weight value of an industrial robot. Background Technology

[0004] This disclosure generally relates to the field of industrial robot control, and more specifically to a method for automatically setting the payload weight value of a collaborative robot, wherein one or more objects are picked up by a robot gripper, the weight of the objects is automatically determined by a force sensor and the weight is used as the payload, and the payload value is automatically adjusted when any object in the group is unloaded.

[0005] Discussion of related technologies

[0006] As is well known, industrial robots are used to perform a wide range of manufacturing, assembly, and material handling operations. Many of these operations and tasks are performed by articulated robots (such as five-axis or six-axis robots) with servo motors at each rotary joint. Control of such robots is provided in real time, where the motion program is divided into small motion increments, and the robot controller performs real-time feedback control calculations to calculate the joint motor input commands that cause the center point of the robot arm tool to move along a prescribed trajectory.

[0007] A common type of robotic task is material handling, which involves moving packages or workpieces from a starting position to a destination. A specific application of this type involves a robot equipped with a vacuum gripper tool that picks up packages (e.g., boxes) and moves them to a designated location. This type of robotic operation is often used for depalletizing or palletizing (i.e., moving boxes from a pallet to a conveyor, or vice versa).

[0008] In operations of the types described above, it is necessary to know the weight of the "payload," or the weight of the object being moved by the robotic arm. The payload is generally considered to include the gripper (typically a vacuum gripper of considerable weight) and one or more boxes carried by that gripper at any given time. The payload weight value is used to calculate the robotic arm end-effector trajectory and the corresponding velocities and accelerations, which keep the robot joint loads within specified limits and also prevent the boxes from detaching from the vacuum gripper.

[0009] Some applications require the use of collaborative robots, which are robots designed to be used in conjunction with human operators in a workspace. Collaborative robots include control features to prevent forceful contact between the robot or its payload and the human operator. In collaborative robot applications, in addition to the trajectory calculation purposes described above, payload weight values ​​are used to establish control parameters that detect contact with any obstacles in the workspace.

[0010] Various methods have been used to set the payload weight value for the robot. In the simplest case, the robot moves only one box at a time, each box has the same weight, and this weight is known. In this case, the payload weight value is either the weight of the gripper (if the gripper is not carrying a box) or the weight of the gripper plus the known weight of the box (if the gripper is carrying a box).

[0011] However, most real-world applications are more complex, involving boxes of varying sizes and weights on a single pallet, and requiring robots to simultaneously pick up multiple boxes, unload some boxes in one location and others in another, and so on. In such applications, determining the payload weight can be complex and time-consuming.

[0012] One known technique for establishing payload weight values ​​is to simply measure the weight of all the boxes being transported after each gripping or releasing operation. Weight measurement can be performed using force sensors mounted on the robotic arm near the vacuum gripper. The drawback of this technique is that the robot must stop after each gripping or releasing operation, and the weight measurement takes time. These measurement delays significantly reduce the productivity of robots performing package movement.

[0013] Even when the box weights are known (either all boxes have the same weight or boxes have a variety of known weights), most palletizing / depalletizing operations still require the flexibility to pick up and release different numbers and combinations of boxes based on the composition of a particular pallet. For example, in one task, the robot might need to pick up three boxes of different weights and depalletize them one by one at different locations, and in the next task, the robot might need to pick up four boxes of the same weight and depalletize them in pairs, one by one, and one by one. Each of these different task combinations requires a specific payload scheduler, where each payload scheduler identifies the payload weight value at each of the multiple steps in the task. This quickly leads to a proliferation of payload schedulers that are difficult to keep track of and require complex custom programming to integrate with the robot controller.

[0014] In view of the above, there is a need for an improved method for setting payload weight values ​​without defining a payload schedule or custom programming, and without causing unnecessary delays in package weighing. Summary of the Invention

[0015] This disclosure describes a method and system for automatically setting the payload weight value of a collaborative robot, wherein one or more objects are picked up by a robot gripper, 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 is unloaded. Only one weight measurement is required when all objects are known to have the same weight, and objects of different weights can be handled by performing a weight measurement for each object. The system automatically handles payload compensation without requiring a payload scheduler or custom programming. The robot uses the payload weight value when it detects any externally applied force indicating contact with the operator or other objects, and when ensuring that the payload acceleration does not exceed the gripping force capacity or robot joint load limits.

[0016] Additional features of the currently disclosed systems and methods will become apparent from the accompanying drawings, the following description, and the appended claims. Attached Figure Description

[0017] Figure 1 The illustration shows an industrial robot equipped with a vacuum gripper tool, in which the package is attached to the vacuum gripper and being moved by the robot, as an example of an application that can benefit from the technology disclosed herein. Figure 2 The illustrations, including pallets containing multiple identical boxes and pallets containing boxes of different sizes and weights, further depict application examples that can benefit from the technology disclosed herein. Figure 3This is a flowchart of a prior art known in the art for setting payload weight values ​​using a payload scheduling table in robotic palletizing or depalletizing operations; Figure 4 This is a flowchart illustrating a method for automatically setting the payload weight value of a robot picking up and placing a single box according to embodiments of the present disclosure; and Figure 5 This is a flowchart of a method for automatically setting the payload weight value of a robot picking up and placing multiple boxes according to an embodiment of the present disclosure. Detailed Implementation

[0018] The following discussion of embodiments of this disclosure relating to the setting of automated payloads for collaborative robots is merely exemplary in nature and is in no way intended to limit the disclosed apparatus and techniques or their application or use.

[0019] Industrial robots are used in a variety of manufacturing, assembly, and material movement operations. In one type of application, robots are used to move workpieces or packages from one location to another. A specific example of robotic package movement is called depalletizing, where boxes are removed from a stack on a pallet and moved to a destination location (such as a conveyor). The reverse operation (picking boxes from a conveyor and placing each box at a specific location on a pallet) is called palletizing and is also commonly used.

[0020] Figure 1 This is an illustration of an industrial robot 100 equipped with a vacuum gripper 120, wherein a package 130 is attached to the vacuum gripper 120 and is being moved by the robot 100, as an example of an application that can benefit from the technology disclosed herein. The robot 100 includes an articulated robotic arm with a plurality of links 110, wherein the links 110 are coupled together at rotary joints actuated by servo motors known to those skilled in the art. The vacuum gripper 120 is a tool used by the robot 100, wherein the vacuum gripper 120 is coupled to the outer arm links or wrist joint of the robot 100. When the package 130 is as... Figure 1 When dealing with boxes as shown, or multiple boxes as discussed below, the vacuum clamp 120 is a commonly used tool.

[0021] Robot 100 communicates with controller 140 in a manner known in the art, wherein controller 140 provides joint movement commands to robot 100, causing robot 100 to move vacuum gripper 120 to a target position for grasping package 130, and subsequently, via movement commands, causes robot 100 to move gripper 120 to a destination position for placing and releasing package 130. When grasping multiple boxes, they can be placed in different positions or all in the same position.

[0022] The load sensor 150 can be positioned on the robot 100, such as at the location between the outer arm link 110 and the vacuum gripper 120 as shown in the figure. Depending on the specific robot model, other locations may be available 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 a measurement to the controller 140. In typical palletizing / depalletizing operations, under static conditions, the force or load value measured by the sensor 150 is the weight of the gripper 120 and one or more boxes (i.e., packages 130) attached to the gripper 120.

[0023] Figure 2 The illustrations, including a tray 200 containing multiple identical boxes and a tray 220 containing boxes of different sizes and weights, further depict application examples that can benefit from the technology disclosed herein. The tray 200 includes multiple boxes 210, each of which is identical. The weight of each box in the box 210 may or may not be known in advance. Note that each layer of the tray 200 includes two boxes facing different directions, which is quite common. A vacuum gripper on a robotic arm is capable of rotating to pick up two boxes placed side-by-side (regardless of their orientation), or two boxes facing the same direction and a third box facing a different direction, to name just a few.

[0024] Pallet 220 contains multiple boxes of three different sizes and shapes, including several of each of boxes 230, 240, and 250. Pallet 220 is depicted as having separate layers, each containing only one specific size of box, but this is not necessarily the case. On mixed-size pallets, different package sizes can be placed on the same layer, and parallel layers are not even necessarily present. Furthermore, mixed-size pallets can include boxes of the same size but different weights.

[0025] from Figure 2 The depalletizing operation can be readily observed, in which pallets such as pallet 200 or pallet 220 are presented to a robot, which picks up boxes from the pallets and moves them elsewhere. As previously mentioned, the techniques of this disclosure discussed below are also applicable to palletizing operations, in which boxes or other packages are picked up from a location (such as a truck or conveyor) and placed on a pallet being constructed in a specific location and orientation.

[0026] Some palletizing and depalletizing operations (such as those discussed above) are performed by articulated robots mounted on mobile bases. These robots can then be moved to desired locations to perform palletizing or depalletizing operations near trucks, loading docks, conveyors, etc. Some of these types of operations are performed using collaborative robots in the presence of a human operator.

[0027] Accurately setting the payload weight value for robot material movement operations is crucial for several reasons. First, the payload value is used to calculate the robot's trajectory and acceleration when moving an object from one location to another—heavier payloads may require reduced acceleration during material movement to avoid exceeding the gripping capacity of the vacuum gripper or the robot's joint load limits. Second, the payload weight value is used to control the collaborative robot's movement to detect contact between the robot and / or its payload and any obstacles, including human operators. If the payload weight value is set too high, the collaborative robot may not stop as expected in the event of accidental contact. If the payload weight value is set too low, the robot controller may interpret normal operational loads as contact indications, triggering a robot stop command. This then requires the operator to manually clear the fault to resume operation, resulting in unnecessary robot downtime.

[0028] Robotic material handling operations, such as palletizing and depalletizing, are frequently performed in warehouses and factory floors that process a variety of items. In other words, a robot might unplacing several pallets of boxes from a truck, all of the same size and weight, and then the robot might be used to palletize boxes of varying sizes and weights arriving from a conveyor. In the past, the flexibility of this type of task required defining and programming numerous payload schedules for the robot, where an appropriate payload schedule was selected for each specific task at the start of each task.

[0029] A payload scheduling table is a document or data table that defines the payload weight values ​​for a specific combination of packages carried by a vacuum gripper.

[0030] Figure 3 This is a flowchart 300 of prior art known in the art for setting payload weight values ​​using a payload scheduler in robotic palletizing or depalletizing operations. At box 310, a robot with a vacuum gripper picks up multiple boxes from a pallet, conveyor, or other source. In this example, these boxes all have the same size and known weight. At box 320, the first step of selecting the payload scheduler is performed based on the number of boxes picked up. In this example, three boxes have already been picked up, therefore, according to the box unloading plan, there are three possible paths for selecting the payload scheduler.

[0031] At box 330, the plan is to unload a box (e.g., onto a pallet or conveyor). Therefore, at box 332, the payload scheduler labeled #3 is selected, where the payload is set based on the number of boxes and reset after unloading based on the new number of boxes after reducing one.

[0032] At box 340, the plan is to unload two boxes. Therefore, at box 342, the payload scheduler labeled #2 is selected, where the payload is set based on the number of boxes and reset after unloading based on the number of new boxes after reducing the number of boxes by two.

[0033] At box 350, the plan is to unload three boxes. Therefore, at box 352, the payload scheduler labeled #1 is selected, where the payload is set based on the number of boxes and reset after unloading based on the number of new boxes after reducing the number of boxes by three.

[0034] At box 360, one or more boxes are unloaded at the designated location. The process then moves to decision diamond 370, where it is determined whether the unloading that was just completed was the last unloading in the current loop (i.e., whether the gripper is currently empty). If the gripper is not empty, the process returns to box 320, where a new current box quantity is set, and a new payload scheduler is selected from one of the three paths based on the planned next unloading quantity.

[0035] From the judgment rhombus 370, if the final unloading value is true (i.e., the gripper is empty), the process moves to box 380, where the robot starts the next loop by picking up multiple boxes at box 310.

[0036] Even in Figure 3 In this simple example, it is evident that a payload scheduler needs to be developed and custom robot logic must be programmed to accommodate all anticipated combinations of box pick-up and unloading sequences. A typical real-world palletizing / depalletizing operation using a modern industrial robot might involve handling 20 to 30 different types of boxes, each with different sizes and weights. Meanwhile, a vacuum gripper can pick up up to 10 boxes at a time and then unload them individually or in groups. The sheer number of package weights and pick-up / unloading options results in a vast number of possible payload combinations, potentially 200 or more. Using existing methods, each of these possible payloads would require a defined payload scheduler, and custom robot programming would need to be created to accommodate such combinations. Figure 3 The method described integrates the payload scheduler into robot operations. Managing all these complexities is both labor-intensive and error-prone.

[0037] Another technique for setting payload weight values ​​has been developed that eliminates the need for complex payload scheduling tables and programming. This technique involves measuring the payload weight after each pick-up or place-down operation and setting the payload weight value accordingly. While simple and flexible, this technique adds a considerable delay to pick-up and place-down operations.

[0038] Consider an example where a robot picks up four boxes and unloads them one at a time. In this example, the robot needs to measure the weight of the boxes four times: 1) when picking up the boxes, measure the weight of all four boxes; 2) when unloading one box, measure the weight of the remaining three boxes; 3) when unloading one box, measure the weight of the remaining two boxes; 4) when unloading one box, measure the weight of the remaining box.

[0039] like Figure 1 As depicted, a typical industrial robot equipped with a vacuum gripper and load sensors requires approximately 1.8 seconds to accurately record the weight value. When weight measurement is required after each pick-up and place-down step, the measurement delay accumulates to a significant and undesirable amount of time. In the example above, with four measurement steps, the total measurement delay per cycle is 7.2 seconds (4... 1.8). Considering that such robots can currently handle up to 10 boxes per picking cycle, the measurement latency could be as high as 18 seconds. These latency issues severely impair robot productivity.

[0040] The techniques disclosed herein were developed to overcome the limitations of existing technologies, including the need for complex payload scheduling tables and integrated programming, as well as the delays associated with measuring payload weight at each step. These techniques are discussed below.

[0041] This disclosed payload compensation method incorporates several key concepts that improve robot productivity and reduce complexity. First, the disclosed method eliminates payload schedule definition and custom programming by simply using either a full gripper payload or an empty gripper payload, where the full gripper payload can be adjusted during package pick-up / placement cycles. Next, the disclosed method includes user-configurable settings that specify whether the pick-up / placement operation involves moving boxes of uniform or dissimilar weights. Furthermore, the disclosed method provides automatic payload weighing via a load sensor mounted on the robot, but only measures the payload weight when needed, thus eliminating many unnecessary measurement delays. Automatic weighing on demand also eliminates the need for external weighing equipment (such as scales) and eliminates the need to create payload schedules based on externally measured weights.

[0042] Figure 4 This is a flowchart 400 of a method for automatically setting the payload weight value of a robot picking up and placing a single box according to an embodiment of the present disclosure. At box 410, the robot picks up a single box, such as from a conveyor, bin, or pallet. At decision diamond 420, it is determined whether the boxes being processed have a consistent weight (all are the same, such as...). Figure 2 The pallet in the middle (200) or does not have a consistent weight (at least two different weights (such as Figure 2The specification of whether the box weight is consistent or inconsistent is a user-configurable setting that can be selected on the user interface screen of the robot controller (or the corresponding remote control device, teach pendant, etc.).

[0043] If all boxes have the same weight, then at decision rhombus 430, it is determined whether the currently picked-up box is the first box in the pick / place operation. For example, when the first box is picked up from pallet 200, the determination at decision rhombus 430 will be yes, indicating that this is the first box. Thereafter, for the remainder of pallet 200 and any other pallets with this composition, the determination at decision rhombus 430 will be no.

[0044] If the determination at rhombus 430 is yes, it is the first box, then at box 440, the robot uses the onboard load sensor (e.g., ...). Figure 1 The load sensor 150 measures the weight of the box. At box 450, a "full gripper load schedule" is set up using the known empty gripper load plus the weight of the box measured at box 440. The robot uses the full gripper load schedule for the current pick / place cycle. At box 452, the robot unloads the box into a designated location (such as a bin, pallet, or conveyor) according to the requirements of the palletizing / depalletizing operation. After unloading the only box, the load schedule is switched to an empty gripper load schedule at box 460, which is predefined based on the weight of the gripper only. The process then loops back to box 410 where the robot picks up another box.

[0045] For each subsequently picked box, as long as the box weight is specified to be consistent, the process moves directly from decision diamond 430 to box 450, where the full gripper payload scheduler is selected using the same value as before, since the box weights are known to be the same. Therefore, the box weight measurement at box 440 is skipped, thus avoiding unnecessary measurement delays.

[0046] If the boxes have inconsistent weights, the process moves from decision diamond 420 to frame 470, where the robot measures the box weight using its onboard load sensor. At frame 480, a full gripper load schedule is set up using the known empty gripper load plus the box weight measured at frame 470. The robot uses the full gripper load schedule for the current pick / place cycle. At frame 482, the box is unloaded by the robot at the designated location. After unloading the only box, the load schedule is switched to the empty gripper load schedule at frame 490. The process then loops back to frame 410, where the robot picks up another box. For each subsequently picked box, whenever the box weight is specified as inconsistent, the process moves from decision diamond 420 to frame 470, where the new box weight is measured.

[0047] Still referencing Figure 4 When following the left side of the flowchart (consistent box weight), the disclosed method provides an automatic measurement of the box weight on the first iteration and then skips weight measurements in all subsequent loops, resulting in significant time savings.

[0048] When following the right side of flowchart 400 (inconsistent box weights), the user only needs to specify the empty gripper payload and begin production. In contrast, with existing technology, a payload scheduler must be defined for each possible box weight. These payload schedulers must be integrated with custom programming and control software, and the correct payload scheduler must be selected for each individual box picked up by the robot.

[0049] Based on the above discussion, it is evident that the automatic payload compensation method disclosed herein offers advantages over existing methods for both operations with consistent box weights and operations with inconsistent box weights.

[0050] Figure 5 This is a flowchart 500 of a method for automatically setting the payload weight value of a robot to pick up and place multiple boxes according to an embodiment of the present disclosure. At box 510, a robot picks up multiple boxes (from a conveyor, bin, or pallet, etc.). The number of boxes picked up at box 510 is known.

[0051] At rhombus 520, determine whether the boxes being processed have a consistent weight (all are the same, such as...). Figure 2 The pallet in the middle (200) or does not have a consistent weight (at least two different weights (such as Figure 2 The specification of whether the box weight is consistent or inconsistent is a user-configurable setting that can be selected on the user interface screen of the robot controller (or the corresponding remote control device, teach pendant, etc.).

[0052] If all boxes have the same weight, then at box 530, the robot uses an onboard load sensor (e.g., Figure 1 The load sensor 150 measures the weight of all boxes. At box 540, the weight of each individual box is calculated based on the known weight of the empty gripper, the weight of all boxes measured from box 530, and the known number of boxes. This is done by subtracting the weight of the empty gripper from the weight of the full gripper and dividing the difference by the number of boxes.

[0053] At box 542, a "full gripper load schedule" is set up using the known empty gripper load plus the weight of the currently gripped box (which, on the first execution, equals the weight measured at box 530). The full gripper load schedule is used by the robot for the current pick / place cycle until a portion of the load is unloaded. At box 544, the robot unloads a known number of boxes into designated locations (such as bins, pallets, conveyors, etc.) according to the requirements of the palletizing / depalletizing operation. After unloading one or more boxes, at decision diamond 550, it is determined whether the last box has been unloaded. If it has, the load schedule is switched to the empty gripper load schedule at box 560, and the process then loops back to box 510, where the robot picks up another set of boxes.

[0054] From decision diamond 550, if the gripper is not empty, the process returns to box 540 to recalculate the weight of the currently gripped boxes. This is done by determining how many boxes are still attached to the gripper (original number minus the number unloaded), multiplying by the known weight of each box, and adding that result to the gripper weight. At box 542, the "full" gripper payload scheduler is adjusted to the weight of the currently gripped boxes plus the gripper weight, and this payload value is used until more boxes are unloaded. After more boxes are unloaded at box 544, decision diamond 550 again checks if the gripper is empty, and the process continues in this manner.

[0055] Figure 5 The process on the left allows for the phased unloading of payloads (e.g., 8 to 10 boxes) of multiple boxes without remeasuring the weight of the remaining boxes or defining any payload scheduling table. All of this is handled automatically as discussed above. In fact, the measurement at box 530 can be skipped after the first one, as long as the box weights are specified consistently, since the total box weight can be determined based on the known weight of each box and the number of boxes grabbed at box 510.

[0056] If the boxes have inconsistent weights, the process moves from decision rhombus 520 to box 570, where the robot uses its onboard load sensor to measure the weight of the box. At box 572, a full gripper load schedule is set up using the known empty gripper load plus the weight of the box measured at box 570. Alternatively, if the weight measured at box 570 includes the gripper along with the box, that measured weight is used for the full gripper load schedule. The full gripper load schedule is used by the robot for the current pick / place cycle.

[0057] At box 574, the robot unloads a known number of boxes at the designated location. After unloading one or more boxes, at decision diamond 580, it is determined whether the last box has been unloaded. If it has been unloaded, then at box 590, the payload scheduler is switched to the empty gripper payload scheduler, and the process then loops back to box 510, where the robot picks up another set of boxes.

[0058] Starting at decision diamond 580, if the gripper is not empty, the process returns to box 570 to measure the weight of the currently gripped box. At box 572, the "full" gripper payload scheduler is adjusted to the weight of the currently gripped box plus the gripper weight, and this payload value is used until more boxes are unloaded. After more boxes are unloaded at box 574, the gripper is again checked for emptiness at decision diamond 580, and the process continues in this manner.

[0059] When following the right side of flowchart 500 (inconsistent box weights), the user only needs to specify the empty gripper payload and begin production. In contrast, with existing technology, payload schedulers must be defined for every possible combination of box weights (potentially hundreds), these schedulers must be integrated with custom programming and control software, and the correct payload scheduler must be selected for each combination of boxes picked up by the robot.

[0060] right Figure 5 The discussion makes it clear that the advantages of the disclosed automatic payload compensation method are applicable to multi-box picking operations (boxes of the same weight and boxes of different weights).

[0061] The automatic payload compensation technique 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 pick-up (typically picking up boxes of unknown weight from a conveyor and placing them on another conveyor, pallet, or other location), bin pick-up (grabbing all objects of the same type from a bin and moving them to another location), and "pick-up one by one" (grabbing different types of objects from a bin individually and moving them to another location). Furthermore, the disclosed technique is applicable to both collaborative and non-collaborative industrial robots.

[0062] Throughout the preceding discussion, various computers and controllers have been described and implied. It should be understood that the software applications and modules of these computers and controllers are executed on one or more electronic computing devices having processors and memory modules. Specifically, this includes one or more processors in the robot controller 140 discussed above. Specifically, the processors in controller 140 are configured to perform the automatic payload compensation techniques described above.

[0063] While numerous exemplary aspects and implementations of methods and systems for automatic load compensation have been discussed above, those skilled in the art will recognize modifications, arrangements, additions, and sub-combinations thereof. Therefore, it is intended that the appended claims and the claims introduced herein be construed as including all such modifications, arrangements, additions, and sub-combinations within their true spirit and scope.

Claims

1. A method for setting the payload weight value of an industrial robot, the method comprising: Provides multiple objects that can be grabbed; A certain number of the objects are grasped by a gripper equipped on the robot; The total weight of the given number of objects is measured using a load sensor fitted to the robot or the gripper. The payload weight value is set using the total weight of the specified number of objects and including the known weight of the empty gripper. When all the objects being gripped have the same weight, the weight of each object is determined by dividing the total weight by the number, the gripper is moved to the destination position, a subset of the certain number of objects is unloaded, and the payload weight value is reduced by the amount equal to the number of unloaded objects multiplied by the weight of each object. as well as When the objects being gripped are not all of the same weight, the gripper is moved to the destination position, a subset of the certain number of objects is unloaded, the new weight of the reduced number of objects is measured using the load sensor, and the payload weight value is set using the new weight.

2. The method of claim 1 further includes unloading the next subset of the certain number of objects and resetting the payload weight value until the gripper is empty, at which point the payload weight value is set to the empty gripper weight value.

3. The method according to claim 1, wherein, When the certain number of objects constitute one object and all the objects that can be gripped have the same weight, the process involves gripping the object, measuring only the weight of the first object in the object, setting the payload weight value using the weight of the first object in the object and including the known empty gripper weight value, releasing the object, and repeating the gripping and releasing of other objects in the object without measuring the weight of each of the other objects.

4. The method according to claim 1, wherein, When the certain number of objects constitute one object, and all the objects that can be grasped do not have the same weight, the process involves grasping the object, measuring the weight of the object, setting the payload weight value using the weight of the object and including the known empty gripper weight value, releasing the object, and repeating the grasping and releasing of other objects, including measuring the weight of each of the other objects.

5. The method according to claim 1, wherein, The payload weight value is used to calculate the trajectory of the object moved by the robot, wherein the trajectory includes the spatial path of the gripper and the velocity and acceleration curves along the spatial path.

6. The method according to claim 5, wherein, The trajectory calculation includes calculating the robot joint load and gripper-object force based on the trajectory and the payload weight value, and recalculating the trajectory until the robot joint load and gripper-object force do not exceed the corresponding predefined limit when the robot joint load or the gripper-object force exceeds the limit.

7. The method according to claim 5, wherein, The robot is a collaborative robot configured to operate in conjunction with a human operator in a neighboring robot, and wherein the payload weight value is also used to establish a threshold for the external force that triggers the robot to stop moving.

8. The method according to claim 1, wherein, The robot performs palletizing or depalletizing operations by grasping and moving the objects.

9. The method according to claim 1, wherein, The gripper is a vacuum gripper comprising a plurality of suction elements that can be individually and selectively activated, wherein each of the objects is gripped by activating one or more of the suction elements and released by deactivating the one or more of the suction elements.

10. The method according to claim 1, wherein, Configuration parameters indicating whether the objects available for grasping all have the same weight are defined before grasping the specified number of objects.

11. A method for setting the payload weight value of an industrial robot, the method comprising: Provide multiple objects that can be grasped, wherein configuration parameters are defined to indicate whether the objects that can be grasped all have the same weight; A number of the objects are grasped by a gripper equipped to the robot, wherein the gripper is a vacuum gripper comprising a plurality of suction elements that can be activated individually and selectively, wherein each of the objects is grasped by activating one or more of the suction elements. The total weight of the given number of objects is measured using a load sensor fitted to the robot or the gripper. The payload weight value is set using the total weight of the specified number of objects and including the known weight of the empty gripper. When all the objects being gripped have the same weight, the weight of each object is determined by dividing the total weight by the number, the gripper is moved to the destination position, a subset of the certain number of objects is unloaded, and the effective load weight value is reduced to the amount equal to the number of unloaded objects multiplied by the weight of each object. When the grasped objects are not all of equal weight, the gripper is moved to the destination location, a subset of the certain number of objects is unloaded, the load sensor is used to measure the new weight of the reduced number of objects, and the new weight is used to set the payload weight value; and Unload the next subset of the given number of objects and reset the payload weight value until the gripper is empty, at which point the payload weight value is set to the empty gripper weight value. The payload weight value is used to calculate the trajectory for moving the gripper to the destination location, wherein the trajectory includes the spatial path of the gripper and the velocity and acceleration curves along the spatial path.

12. The method according to claim 11, wherein, When the certain number of objects constitute a single object, the single object is grasped, the weight of the single object is measured, the effective load weight value is set using the weight of the single object and including the known empty gripper weight value, the single object is released, and the grasping and releasing of other objects in the object is repeated, with the weight of each of the other objects in the object being measured only if the objects available for grasping do not all have the same weight.

13. The method according to claim 11, wherein, The trajectory calculation includes calculating the robot joint load and gripper-object force based on the trajectory and the payload weight value, and recalculating the trajectory until the robot joint load and gripper-object force do not exceed the corresponding predefined limit when the robot joint load or the gripper-object force exceeds the limit.

14. The method according to claim 13, wherein, The robot is a collaborative robot configured to operate in conjunction with a human operator in a neighboring robot, and wherein the payload weight value is also used to establish a threshold for the external force that triggers the robot to stop moving.

15. A robot pickup and placement system with automatic payload compensation, the system comprising: An industrial robot equipped with a gripper and a load sensor coupled to the robot and / or the gripper; as well as A robot controller, communicating with the robot, the gripper, and the load sensor, is configured to perform the following steps: The gripper can be used to grasp a certain number of objects from a plurality of objects that can be grasped. The total weight of the given number of objects is measured using the load sensor. The payload weight value is set using the total weight of the specified number of objects and including the known weight of the empty gripper. When all the objects being gripped have the same weight, the weight of each object is determined by dividing the total weight by the number, the gripper is moved to the destination position, a subset of the certain number of objects is unloaded, and the effective load weight value is reduced to the amount equal to the number of unloaded objects multiplied by the weight of each object. as well as When the objects being gripped are not all of the same weight, the gripper is moved to the destination location, a subset of the certain number of objects is unloaded, the load sensor is used to measure the new weight of the reduced number of objects, and the new weight is used to set the payload weight value.

16. The system according to claim 15, wherein, The controller is also configured to unload the next subset of the given number of objects and reset the payload weight value until the gripper is empty, at which point the payload weight value is set to the empty gripper weight value.

17. The system according to claim 15, wherein, The controller is also configured to: when the number of objects is a single object and all the graspable objects have the same weight, grasp the single object, measure only the weight of the first object among the objects, set the payload weight value using the weight of the first object among the objects and including the known empty gripper weight value, release the single object, and repeatedly grasp and release other objects among the objects without measuring the weight of each of the other objects.

18. The system according to claim 15, wherein, The controller is also configured to: when the number of objects constitutes one object and all the objects available for gripping do not have the same weight, grip the one object, measure the weight of the one object, set the payload weight value using the weight of the one object and including the known empty gripper weight value, release the one object, and repeat gripping and releasing other objects among the objects and including measuring the weight of each of the other objects.

19. The system according to claim 15, wherein, The payload weight value is used by the controller to calculate the trajectory of the object moved by the robot, wherein the trajectory includes the spatial path of the gripper and the velocity and acceleration curves along the spatial path.

20. The system according to claim 19, wherein, The trajectory calculation includes calculating the robot joint load and gripper-object force based on the trajectory and the payload weight value, and recalculating the trajectory until the robot joint load and gripper-object force do not exceed the corresponding predefined limit when the robot joint load or the gripper-object force exceeds the limit.

21. The system according to claim 20, wherein, The robot is a collaborative robot configured to operate in conjunction with a human operator in a neighboring location, and the payload weight value is also used to establish a threshold for the external force on the robot that triggers the controller to stop the robot's movement.

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

23. The system according to claim 15, wherein, The gripper is a vacuum gripper comprising a plurality of suction elements that can be individually and selectively activated, wherein each of the objects is gripped by activating one or more of the suction elements and released by deactivating the one or more of the suction elements.

24. The system according to claim 15, wherein, Configuration parameters indicating whether the objects available for grasping all have the same weight are defined before grasping the specified number of objects.

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