Self-adaptive grabbing and releasing method and device

Abstract

The invention discloses a self-adaptive grabbing and placing method which comprises a workpiece taking step and a workpiece placing step, wherein during workpiece taking, a visual positioning module determines initial coordinates of a workpiece, an execution mechanism drives an end effector to conduct grabbing, a multi-dimensional force sensing assembly collects force data in multiple directions in real time to judge whether the force data is abnormal or not, and transferring is conducted when parameters are compared to reach the standard after clamping; during workpiece placing, target coordinates are determined through visual positioning, the executing mechanism carries the workpiece in place, the force sensing assembly cooperates with position information for judgment, and the workpiece is loosened and returns after the workpiece reaches the standard. According to the method, through'position and force 'double-feedback control, fixed coordinates do not need to be preset, tracks, postures and clamping force can be dynamically adjusted, complex scenes such as workpiece deviation and placement surface change can be adapted, stress abnormity can be accurately detected, clamping parameters can be flexibly set, the workpiece damage rate and the equipment failure rate are effectively reduced, and operation adaptability, safety and reliability are improved.

Description

Technical Field

[0001] This invention relates to the field of clamping and handling technology, and specifically to an adaptive gripping and releasing method and device. Background Technology

[0002] In modern industrial fields such as automated production, precision assembly, and logistics handling, workpiece gripping and placement is one of the core processes. Its efficiency, precision, and safety directly determine the overall production capacity and product quality. As the manufacturing industry transforms towards flexibility and intelligence, production scenarios are becoming increasingly complex. The demands for diverse workpiece types (materials, specifications, and shapes) and dynamic operating environments (such as workpiece placement position offsets, minor deformations of the placement surface, and external interference) are becoming more prominent, making traditional gripping and placement technologies unable to meet the requirements of practical applications.

[0003] Existing gripping and placing technologies mostly rely on fixed-position control modes, that is, preset fixed coordinates of the workpiece, and drive the end effector to complete the gripping and placing action by the actuator along a fixed trajectory. Its limitations are very significant: First, the position adaptability is extremely poor, and it cannot cope with dynamic scenarios such as workpiece position offset and slight changes in the placement surface, which easily leads to gripping failure or placement deviation. Second, pure position control lacks a force feedback mechanism, and cannot detect collisions between the end effector and the workpiece, equipment or surrounding environment in time, which can easily cause workpiece clamping, damage, or even equipment jamming and failure. Third, it lacks versatility. For workpieces of different materials and specifications, trajectory parameters need to be readjusted or the end effector needs to be replaced, which is costly and inefficient. Fourth, it lacks a sound anomaly handling and retry mechanism. Once problems such as gripping deviation or abnormal force occur, the system often shuts down directly, requiring manual intervention for troubleshooting, which seriously affects production continuity and increases manual maintenance costs. In addition, although some improved technologies attempt to incorporate force control functions, they mostly rely on the native software of the actuator itself to estimate the end force, resulting in low detection accuracy and slow response. They are only suitable for low-precision handling scenarios and cannot meet the operational needs of precision assembly and other operations that require high coordination between force control and positioning. Summary of the Invention

[0004] The purpose of this invention is to solve the problem that traditional fixed position control cannot cope with dynamic scenarios such as workpiece position offset and slight changes in the placement surface, which easily leads to gripping and releasing failures, and proposes an adaptive gripping and releasing method.

[0005] The objective of this invention can be achieved through the following technical solutions: An adaptive capture and release method includes: Pickup steps: A1. The visual positioning module obtains the position of the workpiece within the picking area and determines the initial picking coordinates; A2. The actuator drives the end effector to move to the picking position. During the picking process, the multi-dimensional force sensing component collects multi-directional force data in real time to determine whether there is any abnormal force during the picking process. A3. When the force is normal during the part removal process, the end effector clamps the workpiece, collects the clamping force parameters and the opening and closing dimensions of the end effector, and compares them with the preset standard. If they meet the preset standard, the transfer task is executed; otherwise, manual confirmation is required before further processing. Placement steps: B1. The vision positioning module performs position detection on the placement or assembly area to determine the target position coordinates; B2. When the actuator moves the workpiece to the target position and performs the placement action, the multi-dimensional force sensing component collects force data in multiple directions and combines it with the position information of the actuator to jointly determine whether it is in place. The force direction consistent with the placement direction is selected as the main judgment basis, while monitoring the force data in other directions. B3. If the force data and position information meet the preset requirements, the end effector releases the workpiece, and the actuator returns to the origin.

[0006] As a further aspect of the present invention: In step A2, if an abnormal force occurs for the first time, the actuator returns to the position detection area to reacquire the workpiece position and then attempts to pick up the workpiece again; If the abnormality persists after multiple pickups, the actuator returns to its initial position and triggers an alarm.

[0007] As a further aspect of the present invention: the criterion for determining multiple abnormal item retrievals is: at least one of the multi-directional force data detected by the multi-dimensional force sensing component continuously exceeds a preset force threshold.

[0008] As a further aspect of the present invention: In step A3, if the clamping state does not meet the preset standard, it is necessary to manually check and confirm whether the workpiece has any gripping abnormality, not clamped or other faults before deciding to remove the workpiece or re-grip it.

[0009] As a further aspect of the present invention: In step B2, if the force in the main judgment direction does not reach the preset range or the force in other directions exceeds the set threshold, the actuator stops its operation and returns to the starting point, and after shifting a preset distance in the opposite direction of the force exceeding the limit, it tries again. If the abnormal situation occurs a preset number of times or more, the actuator will return to the origin and trigger an alarm.

[0010] As a further aspect of the present invention: in step B2, the part is determined to be placed or assembled in place only when the force in the main judgment direction reaches the preset range and the forces in other directions do not exceed the set threshold.

[0011] As a further aspect of the present invention: the multidimensional force sensing component is a sensing device that includes at least three-dimensional linear direction and three-dimensional rotational direction force sensing functions; or A sensing structure that can detect forces in multiple directions.

[0012] As a further aspect of the present invention: the multi-dimensional force sensing component is a six-dimensional force sensor.

[0013] An adaptive gripping and releasing device is used to implement an adaptive gripping and releasing method, the adaptive gripping and releasing device comprising: Visual positioning module; A multi-dimensional force sensing component is disposed next to the visual positioning module; A force-controlled flexible gripper is mounted on the multi-dimensional force sensing component.

[0014] As a further aspect of the present invention: the multidimensional force sensing component is a sensing device that includes at least three-dimensional linear direction and three-dimensional rotational direction force sensing functions; or A sensing structure that can detect forces in multiple directions.

[0015] As a further aspect of the present invention: the multidimensional force sensing component is a sensing device that includes at least three-dimensional linear direction and three-dimensional rotational direction force sensing functions; or A sensing structure that can detect forces in multiple directions.

[0016] As a further aspect of the present invention: the multi-dimensional force sensing component is a six-dimensional force sensor.

[0017] As a further aspect of the present invention: the adaptive gripping and releasing device also includes an execution mechanism, wherein the multi-dimensional force sensing component, the force-controlled sensing flexible gripper and the visual positioning module are all mounted on the execution mechanism, and the execution mechanism is a robot or a robotic arm.

[0018] The beneficial effects of this invention are: This invention acquires workpiece position information in real time through a visual positioning module, and combines this with real-time acquisition and analysis of multi-directional force data using multi-dimensional force sensing components to achieve dual feedback control of "position and force". Whether it's workpiece position offset, slight changes in the placement surface, or external interference in the working environment, the system can dynamically adjust the actuator trajectory, end effector posture, and clamping force parameters without needing to preset fixed coordinates, significantly improving its adaptability to complex dynamic scenarios and solving the core pain point of poor adaptability in traditional fixed position control. Precise and safe operation, reducing the risk of damage: With the accurate detection of multi-directional force data (including forces or torques in three-dimensional linear and three-dimensional rotational directions) by multi-dimensional force sensing components, the system can determine abnormal forces during the gripping and releasing process in real time (such as collisions, excessive or insufficient clamping force), and avoid risks through immediate adjustments or retrying after stopping the machine. Simultaneously, the clamping force parameters and end effector opening and closing dimensions can be flexibly set according to workpiece attributes and specifications, effectively preventing workpiece clamping and damage, reducing the probability of equipment collision failures. Compared to traditional pure position control technology, the workpiece damage rate and equipment failure rate are significantly reduced, and operational safety and reliability are greatly improved. Attached Figure Description

[0019] The invention will now be further described with reference to the accompanying drawings.

[0020] Figure 1 This is a flowchart of the component retrieval steps of the present invention; Figure 2 This is a flowchart of the placement steps of the present invention; Figure 3 This is a schematic diagram of the structure of the present invention.

[0021] In the diagram: 1. Visual positioning module; 2. Multi-dimensional force sensing component; 3. Force control sensing flexible gripper. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Pickup steps: The visual positioning module 1 performs position detection on the picking area to obtain workpiece position information and determine the initial picking coordinates; The visual positioning module 1 is a device with spatial position detection function, including but not limited to 3D imaging equipment, visual sensor combination or other positioning devices that can acquire the spatial coordinates of the workpiece. The visual positioning module 1 can be a 3D camera. The actuator drives the end effector to move to the picking position. During the picking process, the multi-dimensional force sensing component 2 collects multi-directional force data in real time to determine whether there is any abnormal force during the picking process. The actuator is a device with motion driving function, including but not limited to industrial robots, robotic arms or other drive mechanisms that can realize end effector displacement control; The end effector is an execution component with workpiece clamping function, including but not limited to flexible grippers, rigid grippers or other clamping structures that can clamp and release workpieces; When the multi-dimensional force sensing component 2 detects an abnormal force, the control system immediately adjusts the attitude or gripping force of the end effector to ensure that the workpiece is gripped stably and without damage; after the gripping is completed, the actuator moves the workpiece to the designated position.

[0024] When the force is normal during the part removal process, the end effector clamps the workpiece, collects the clamping force parameters and the opening and closing dimensions of the end effector, and compares them with preset standards. If they meet the preset standards, the transfer task is executed; otherwise, manual confirmation is required before further processing. Placement steps: The visual positioning module 1 performs position detection on the placement area to determine the target position coordinates; When the actuator moves the workpiece to the target position and performs the workpiece placement action, the multi-dimensional force sensing component 2 collects multi-directional force data and combines it with the position information of the actuator to jointly determine whether the position is in place. The force direction consistent with the placement direction is selected as the main judgment basis, while monitoring the force data in other directions. If the force in the main judgment direction does not reach the preset range or the force in other directions exceeds the set threshold, the actuator stops its operation and returns to the starting point. After shifting a preset distance in the opposite direction of the force exceeding the limit, it tries again.

[0025] The multidimensional force sensing component 2 is disposed between the end effector and the actuator or in the force sensing area of ​​the end effector, and is used to sense the force state of the end effector in real time during the entire process of picking up, placing or assembling parts.

[0026] Further steps are explained below: Pickup steps: Position acquisition: After the control system issues the part picking command, the vision positioning module 1 starts scanning and detecting the part picking area, obtains the spatial position information of the workpiece through 3D imaging technology, determines the initial part picking coordinates after algorithm processing, and transmits the coordinate data to the actuator control system.

[0027] Grasping and Force Detection: Based on the initial pick-up coordinates, the actuator drives the end effector to move above the workpiece and gradually performs the gripping action; during this process, the multi-dimensional force sensing component 2 collects six-axis force or torque data in real time and continuously transmits it to the control system, which determines in real time whether the force exceeds the preset threshold.

[0028] Exception handling: If an abnormal force is detected for the first time (such as any one of the six-axis force data exceeding the threshold, which may be caused by workpiece position deviation, the presence of obstacles, etc.), the actuator immediately stops the grasping action and returns to the detection area of ​​the vision positioning module 1. The vision positioning module 1 takes a new picture of the picking area, updates the workpiece position coordinates, and then the actuator drives the end effector to try to grasp again.

[0029] If abnormal force is detected during the second grab, the actuator will stop the grabbing operation, return to the initial position, and trigger an audible and visual alarm to prompt staff to troubleshoot the fault (such as abnormal workpiece placement, component failure, etc.).

[0030] Clamping status verification: If the force is normal during the workpiece removal process, the end effector continues to clamp the workpiece. The control system collects the clamping force parameters and the opening and closing dimensions of the end effector at this time and compares them with the preset standard. If the data meets the preset range, it is determined that the gripping is qualified, and the actuator drives the workpiece to perform the transfer task and move to the placement or assembly area.

[0031] If the data does not meet the preset range (e.g., not clamped, clamping force is too large), the actuator will pause the transfer. After the staff checks and confirms whether the workpiece is mis-grabbed, damaged, or the end effector is faulty, the staff will decide whether to remove the workpiece or re-grab it.

[0032] Placement or assembly steps: Target position positioning: When the actuator carries the workpiece to the vicinity of the placement or assembly area, the vision positioning module 1 scans and detects the area to obtain the coordinate information of the placement or assembly target position, transmits it to the control system, and calibrates the motion trajectory of the actuator.

[0033] Execution and Coordination of Part Placement or Assembly: The actuator drives the end effector to move the workpiece to the target position and gradually executes the part placement or assembly action; during this process, the multi-dimensional force sensing component 2 collects six-axis force or torque data in real time, and the control system combines the real-time position information of the actuator to make collaborative judgments.

[0034] Setting the primary judgment direction and handling anomalies: Select the force direction consistent with the placement or assembly direction (such as the Z-axis linear direction) as the primary judgment criterion, while monitoring the force data in the other five directions: If the force in the main judgment direction does not reach the preset range (e.g., not contacting the assembly surface), or the force in other directions exceeds the set threshold (e.g., side collision), the control system immediately controls the actuator to stop moving, return to the part placement or assembly starting point, and offset in the opposite direction of the force exceeding the limit by a preset distance (default 0.2mm, which can be adjusted to 0.1~0.5mm according to the actual scenario).

[0035] After the offset is completed, the actuator drives the end effector again to perform the placement or assembly action, repeating the above judgment process.

[0036] Accumulated exception handling and normal completion: If an abnormal situation occurs a preset number of times (default 3 times, which can be adjusted to 2 to 5 times according to production needs), the actuator will stop the part placement or assembly operation, return to the equipment origin and trigger an alarm, waiting for manual handling.

[0037] If the force in the main judgment direction reaches the preset range and the forces in the other five directions do not exceed the set threshold, it is determined that the workpiece has been placed or assembled. The control system controls the end effector to release the workpiece, and the actuator returns to the origin along the preset trajectory to complete a single pick-up and place operation.

[0038] An adaptive gripping and releasing device is used to implement an adaptive gripping and releasing method, the adaptive gripping and releasing device comprising: Visual positioning module 1; The multi-dimensional force sensing component 2 is disposed next to the visual positioning module 1; Force-controlled flexible gripper 3 is mounted on the multi-dimensional force sensing component 2.

[0039] The multidimensional force sensing component is a sensing device that includes at least three-dimensional linear direction and three-dimensional rotational direction force sensing functions; or A sensing structure that can detect forces in multiple directions.

[0040] The multidimensional force sensing component is a six-dimensional force sensor.

[0041] The adaptive gripping and releasing device also includes an actuator, which is a robot or a robotic arm.

[0042] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. An adaptive grasping and releasing method, characterized in that, include: Pickup steps: A1. The visual positioning module obtains the position of the workpiece within the picking area and determines the initial picking coordinates; A2. The actuator drives the end effector to move to the picking position. During the picking process, the multi-dimensional force sensing component collects multi-directional force data in real time to determine whether there is any abnormal force during the picking process. A3. When the force is normal during the part removal process, the end effector clamps the workpiece, collects the clamping force parameters and the opening and closing dimensions of the end effector, and compares them with the preset standard. If they meet the preset standard, the transfer task is executed; otherwise, manual confirmation is required before further processing. Placement steps: B1. The vision positioning module performs position detection on the placement or assembly area to determine the target position coordinates; B2. When the actuator moves the workpiece to the target position and performs the placement action, the multi-dimensional force sensing component collects force data in multiple directions and combines it with the position information of the actuator to jointly determine whether it is in place. The force direction consistent with the placement direction is selected as the main judgment basis, while monitoring the force data in other directions. B3. If the force data and position information meet the preset requirements, the end effector releases the workpiece, and the actuator returns to the origin.

2. The adaptive grasping and releasing method according to claim 1, characterized in that, In step A2, if an abnormal force occurs for the first time, the actuator returns to the position detection area to reacquire the workpiece position and then attempts to pick up the workpiece again. If the abnormality persists after multiple pickups, the actuator returns to its initial position and triggers an alarm.

3. The adaptive grasping and releasing method according to claim 2, characterized in that, The criteria for determining multiple abnormal pickups are: at least one of the multi-directional force data detected by the multi-dimensional force sensing component continuously exceeds the preset force threshold.

4. The adaptive grasping and releasing method according to claim 1, characterized in that, In step A3, if the clamping status does not meet the preset standard, it is necessary to manually check and confirm whether the workpiece has any gripping abnormalities, is not clamped, or has other faults before deciding to remove the workpiece or perform a re-grip operation.

5. The adaptive grasping and releasing method according to claim 1, characterized in that, In step B2, if the force in the main judgment direction does not reach the preset range or the force in other directions exceeds the set threshold, the actuator stops its operation and returns to the starting point. After shifting the force in the direction of the excessive force by a preset distance, it tries again. If the abnormal situation occurs a preset number of times or more, the actuator will return to the origin and trigger an alarm.

6. The adaptive grasping and releasing method according to claim 1, characterized in that, In step B2, the part is determined to be in place or assembled only when the force in the main judgment direction reaches the preset range and the forces in other directions do not exceed the set threshold.

7. An adaptive gripping and releasing device, characterized in that, For implementing the adaptive gripping and releasing method as described in any one of claims 1 to 6, the adaptive gripping and releasing device comprises: Visual positioning module; A multi-dimensional force sensing component is disposed next to the visual positioning module; A force-controlled flexible gripper is mounted on the multi-dimensional force sensing component.

8. The adaptive gripping and releasing device according to claim 7, characterized in that, The multidimensional force sensing component is a sensing device that includes at least three-dimensional linear direction and three-dimensional rotational direction force sensing functions; or A sensing structure that can detect forces in multiple directions.

9. The adaptive gripping and releasing device according to claim 8, characterized in that, The multidimensional force sensing component is a six-dimensional force sensor.

10. The adaptive gripping and releasing device according to claim 7, characterized in that, The adaptive gripping and releasing device also includes an actuator. The multi-dimensional force sensing component, the force-controlled flexible gripper, and the visual positioning module are all mounted on the actuator, which is a robot or a robotic arm.

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