Method, device and medium for controlling a dual-arm robot to assemble a tablet mold shaft hole

Abstract

The application discloses a kind of control method, equipment and medium of two-arm robot assembly tablet press mold shaft hole, belong to shaft hole assembly robot control field, can control two-arm robot and top die of infrared tablet press mold is assembled to the shaft hole in the cylinder, comprising: step 1, the contact state and geometric constraint joint modeling of two-arm robot and cylinder, obtain the shaft hole posture of shaft hole on cylinder;Step 2, with shaft hole posture as reference, estimate the center point position of shaft hole;Step 3, based on shaft hole posture and the center point position of shaft hole, control the motion of two-arm robot clamping top die of tablet press mold to shaft hole enters initial assembly state;Step 4, based on two-arm task priority compliant controller, carry out shaft axial insertion movement and radial compliant adjustment;Step 5, when judging that top die of right mechanical arm reaches preset insertion depth, then control left mechanical arm to release top die, complete the assembly of infrared tablet press mold.This method can meet the requirements of infrared tablet press mold assembly.

Description

Technical Field

[0001] This invention relates to the field of shaft hole assembly robot control technology, and in particular to a control method for assembling the shaft hole of a tablet press mold by a dual-arm robot. Background Technology

[0002] With the rapid development of automated laboratories, the assembly scenarios and task requirements are becoming increasingly complex, and high-precision shaft and hole assembly often becomes a key bottleneck restricting the smooth operation of the overall automated process. For example, in infrared characterization tablet pressing experiments, inserting the top mold into the shaft hole of a cylinder with extremely small assembly tolerances and initial posture deviations is a huge challenge for robots. When performing assembly tasks, humans usually first obtain rough positional information of the parts through visual perception, and then rely on tactile feedback to complete fine operations. Inspired by this, robots currently mainly rely on two methods when performing shaft and hole assembly tasks: visual servoing and force control. Among them, visual servoing is easily affected by factors such as occlusion and changes in lighting, especially in the assembly scenarios of high-precision components, where the lack of force and torque information during the contact stage can easily lead to assembly failure or part damage; while force control usually relies on accurate shaft and hole CAD models and contact parameters (such as the coefficient of friction). In addition, traditional single-arm shaft and hole assembly methods usually rely on stable external constraints, but in real chemical experimental scenarios, this assumption is difficult to meet, resulting in a high degree of coupling between alignment and insertion tasks under weak constraints, which can easily cause interference between position adjustment and insertion movement. Although the shaft-hole assembly method of dual-arm robots can handle such weakly constrained assembly problems, its application in long-process chemical experiments remains relatively limited, especially for the assembly of tableting molds in the infrared characterization of crystals. This indicates that there is currently no collaborative control strategy for dual-arm robots to assemble the shaft holes of the tableting mold and the cylinder for infrared characterization. Therefore, it is impossible to solve the problem of controlling a dual-arm robot to complete the assembly of the top mold and shaft hole of the tableting mold under high precision and weak constraints in the infrared characterization tableting process, thereby meeting the assembly requirements of the tableting mold.

[0003] In view of this, the present invention is hereby proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a control method, equipment, and medium for assembling the shaft hole of a tableting mold using a dual-arm robot. This method enables the dual-arm robot to assemble the top mold of the infrared tableting mold with the shaft hole on the cylinder under high precision and weak constraint conditions during the infrared characterization tableting process, thus meeting the assembly requirements of the infrared tableting mold and solving the aforementioned technical problems in the prior art.

[0005] The objective of this invention is achieved through the following technical solution: A control method for assembling the shaft hole of a tablet pressing mold using a dual-arm robot, used to control the dual-arm robot to respectively clamp the top mold and the assembly consisting of the cylinder and base of an infrared tablet pressing mold, and to assemble the top mold into the shaft hole of the cylinder, including: Step 1: By jointly modeling the contact state and geometric constraints between the dual-arm robot and the cylinder, the orientation of the shaft hole on the cylinder is obtained; Step 2: Based on the obtained shaft hole orientation, estimate the position of the center point of the shaft hole; Step 3: Based on the obtained shaft hole posture and the center point position of the shaft hole, control the dual-arm robot holding the top mold of the infrared pressing mold to move to the shaft hole position and enter the initial assembly state. Step 4: Based on the dual-arm task priority compliance controller, control the dual arms of the dual-arm robot to perform axial insertion motion and radial compliance adjustment of the shaft hole; Step 5: When it is determined that the right robotic arm of the dual-arm robot has moved a given distance along the axis of the shaft hole and reached the preset insertion depth, the left robotic arm of the dual-arm robot is controlled to release the top mold, thus completing the assembly of the infrared pressing mold.

[0006] A processing apparatus, comprising: At least one memory for storing one or more programs; At least one processor is capable of executing one or more programs stored in the memory, such that when the processor executes one or more programs, the processor can implement the method of the present invention.

[0007] A readable storage medium storing a computer program that, when executed by a processor, enables the implementation of the methods described in this invention.

[0008] Compared with the prior art, the control method, equipment and medium for assembling tablet mold shaft holes with a dual-arm robot provided by the present invention have the following advantages: The shaft hole pose is identified by edge contact, and the contact state is judged by end force and torque constraints, thereby effectively reducing the uncertainty in the initial stage of assembly. At the same time, a priority projection operator is introduced to decompose the assembly task, realize the dynamic coordination of axial insertion motion and radial compliance adjustment, and fine adjustment of pose error, thereby quickly correcting the attitude error, reducing control complexity, realizing high-precision compliance assembly of infrared tablet mold under weak constraint conditions, and solving the problem of high-precision assembly of tablet mold in chemical infrared characterization scenarios. Attached Figure Description

[0009] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 A flowchart illustrating the control method for assembling the shaft hole of a tablet press mold using a dual-arm robot, as provided in an embodiment of the present invention.

[0011] Figure 2 This is a schematic diagram of the shaft hole posture edge contact detection of a dual-arm robot in the control method provided in the embodiment of the present invention.

[0012] Figure 3 This is a schematic diagram of a dual-arm robot performing contact detection of the center position of a shaft hole in the control method provided in an embodiment of the present invention.

[0013] Figure 4 This is a schematic diagram illustrating the definition of the assembly task coordinate system in the control method provided in this embodiment of the invention.

[0014] Figure 5 This is a schematic diagram of the control process for the infrared pressing mold assembly task in the control method provided in the embodiment of the present invention. Detailed Implementation

[0015] 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 a part of the embodiments of the present invention, and not all of them, and do not constitute a limitation on the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0016] First, the following explanations are provided for the terms that may be used in this article: The term "and / or" means that either or both can be achieved simultaneously. For example, X and / or Y means that it includes both "X" or "Y" as well as the three cases of "X and Y".

[0017] The terms "comprising," "including," "containing," "having," or other similar semantic descriptions should be interpreted as non-exclusive inclusion. For example, including a technical feature element (such as raw material, component, ingredient, carrier, dosage form, material, size, part, component, mechanism, device, step, process, method, reaction conditions, processing conditions, parameter, algorithm, signal, data, product or article of manufacture, etc.) should be interpreted as including not only the expressly listed technical feature element, but also other technical feature elements that are not expressly listed and are well-known in the art.

[0018] The term "composed of" excludes any technical features not expressly listed. When used in a claim, it closes the claim to exclude all technical features other than those expressly listed, except for associated conventional impurities. If the term appears only in a clause of a claim, it limits the claim to the elements expressly listed in that clause; elements recited in other clauses are not excluded from the overall claim.

[0019] Unless otherwise explicitly specified or limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this document according to the specific circumstances.

[0020] The terms “center,” “longitudinal,” “lateral,” “length,” “width,” “thickness,” “up,” “down,” “front,” “back,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “clockwise,” and “counterclockwise” indicate the current orientation or positional relationship, and are only for the convenience and simplification of description, and do not explicitly or implicitly suggest that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this document.

[0021] The technical solution provided by this invention will be described in detail below. Contents not described in detail in the embodiments of this invention are prior art known to those skilled in the art. Where specific conditions are not specified in the embodiments of this invention, they shall be performed according to conventional conditions in the art or conditions recommended by the manufacturer. Reagents or instruments used in the embodiments of this invention whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0022] like Figures 1 to 5 As shown, this invention provides a control method for assembling the shaft hole of a tablet pressing mold using a dual-arm robot. The method controls the dual-arm robot to respectively clamp the top mold and the assembly consisting of the cylinder and base of the infrared tablet pressing mold, and assembles the top mold into the shaft hole of the cylinder. The method includes: Step 1: By jointly modeling the contact state and geometric constraints between the dual-arm robot and the cylinder, the orientation of the shaft hole on the cylinder is obtained; Step 2: Based on the obtained shaft hole orientation, estimate the position of the center point of the shaft hole; Step 3: Based on the obtained shaft hole posture and the center point position of the shaft hole, control the dual-arm robot holding the top mold of the infrared pressing mold to move to the shaft hole position and enter the initial assembly state. Step 4: Based on the dual-arm task priority compliance controller, control the dual arms of the dual-arm robot to perform axial insertion motion and radial compliance adjustment of the shaft hole; Step 5: When it is determined that the right robotic arm of the dual-arm robot has moved a given distance along the axis of the shaft hole and reached the preset insertion depth, the left robotic arm of the dual-arm robot is controlled to release the top mold, thus completing the assembly of the infrared pressing mold.

[0023] Preferably, in step 1 of the above method, the shaft hole orientation on the cylinder is obtained by jointly modeling the contact state and geometric constraints between the dual-arm robot and the cylinder, including: Step 11: Control the fingertips of the parallel two-finger gripper at the end of the left robotic arm of the dual-arm robot to make contact with the upper surface of the cylinder where the shaft hole is located, and collect no less than three contact feature points on the upper surface of the cylinder. Step 12: Perform plane fitting on the collected contact feature points using the least squares method to calculate the plane normal vector of the upper surface of the cylinder. Step 13: Determine the spatial orientation of the shaft hole on the cylinder based on the obtained plane normal vector.

[0024] See Figure 2 Preferably, in step 11 of the above method, the gripper tips of the parallel two-finger gripper at the end of the left robotic arm of the dual-arm robot are controlled to contact the upper surface of the cylinder where the shaft hole is located in the following manner, and at least three contact feature points on the upper surface of the cylinder are collected, including: The gripper tips of the parallel two-finger gripper at the end of the left robotic arm of the dual-arm robot come into contact with the upper surface of the cylinder. When the force feedback signal at the end of the left robotic arm reaches a preset threshold, the position of the parallel two-finger gripper at the end of the left robotic arm in the world coordinate system at the corresponding moment is recorded. This position is the contact feature point position between the gripper tips of the parallel two-finger gripper at the end of the left robotic arm and the upper surface of the cylinder.

[0025] In step 12, the collected contact feature points are fitted using the least squares method to obtain the plane normal vector of the upper surface of the cylinder, including: Step 121, for the collected n contact feature points The least squares method is used for plane fitting. To indicate the index of the contact feature points, first, the centroid of the contact feature point set is... Defined as:

[0026] ; Subsequently, a decentralized matrix is ​​constructed based on each contact feature point. ,for: ; Among them, superscript Represents the transpose of a matrix; Represents the set of real numbers; Decentralized matrix Construct the covariance matrix ,for: ; Singular Value Decomposition (SVD) of the covariance matrix Eigenvalue decomposition yields eigenvectors, and the eigenvector corresponding to the smallest eigenvalue is taken as the unit normal vector of the upper surface of the cylinder. : ; in, Describes the function that minimizes the value. The independent variable that achieves its maximum value; Represents a unit direction vector in three-dimensional space. Represents the unit direction vector Size; This represents the magnitude of the variance of the contact feature point in that direction, and the direction corresponding to the minimum variance is the plane normal vector of the upper surface of the cylinder.

[0027] In step 13, the spatial orientation of the shaft hole on the cylinder is determined based on the obtained plane normal vector in the following manner: Since the direction of the shaft hole axis is consistent with the direction of the plane normal vector on the upper surface of the cylinder, the spatial attitude of the shaft hole is determined using the obtained plane normal vector. This spatial attitude direction is expressed in Euler angle form as follows: Pitch angle in Euler angles : ; Roll angle in Euler angles : ; Yaw angle in Euler angles : ; in, Represents the arctangent function; , and They represent the unit normal vectors respectively. The components in the x-axis, y-axis, and z-axis directions of the reference coordinate system.

[0028] Preferably, in step 2 of the above method, the center point position of the shaft hole is estimated based on the obtained shaft hole orientation in the following manner: Step 21: Control the gripper posture of the parallel two-finger gripper at the end of the left robotic arm of the dual-arm robot to be consistent with the posture of the shaft hole, and collect three feature contact points on the side wall of the cylinder. Step 22: Combine the characteristic contact points on the sidewall collected in Step 21 into a characteristic point combination, calculate and solve the coordinates of the shaft hole center point of each group of characteristic point combinations, and take the average value of the shaft hole center point coordinates calculated by each group of characteristic point combinations as the estimated shaft hole center point coordinates. Step 23: Determine the position of the center point of the shaft hole based on the coordinates of the center point of the shaft hole obtained in Step 22.

[0029] Preferably, in step 21 of the above method, the gripper posture of the parallel two-finger gripper at the end of the left robotic arm of the dual-arm robot is controlled to be consistent with the posture of the shaft hole in the following manner, and three characteristic contact points on the side wall of the cylinder are collected, including: During the process of controlling the contact between the gripper of the parallel two-finger gripper at the end of the left robotic arm of the dual-arm robot and the side wall of the cylinder, the gripper is controlled to make contact with the side wall of the cylinder. When the force feedback signal at the end of the left robotic arm reaches a preset threshold, the spatial pose of the parallel two-finger gripper at the end of the left robotic arm is recorded. The control ensures that the pose of the gripper of the parallel two-finger gripper is always consistent with the Euler angle obtained in step 13, and ensures that the axis of the shaft hole is perpendicular to the plane formed by the collected feature contact points. When the gripper of the parallel two-finger gripper at the end of the left robotic arm closes and the end is attached to the upper surface of the cylinder, the gripper pose is defined as the central detection reference coordinate system. Then the gripper opens and moves a fixed distance along the positive z-axis of the central detection reference coordinate system. Then it moves in the xoy plane of the central detection reference coordinate system to obtain e feature contact points. Any three feature contact points are selected from the e feature contact points. In step 22, the characteristic contact points collected in step 21 are combined into contact point combinations in the following manner, the coordinates of the shaft hole center point of each contact point combination are calculated, and the average value of the shaft hole center point coordinates calculated for each contact point combination is taken as the estimated shaft hole center point coordinates, including: Combine the three feature contact points selected in step 21 into For each combination of contact points, geometric operations are performed to solve for the coordinates of the center point of the shaft hole. The arithmetic mean of the center point coordinates obtained from all the contact point combinations is taken as the estimated coordinates of the center point of the shaft hole.

[0030] Preferably, in step 23 of the above method, the center point position of the shaft hole is determined according to the coordinates of the shaft hole center point obtained in step 22 in the following manner: When calculating the position of the center point of the shaft hole, three characteristic contact points obtained in the center detection reference coordinate system are used. , and Determine the characteristic contact points Contact points with features The straight line With the straight line perpendicular bisector Then the perpendicular bisector With a straight line The coordinates of the intersection point for: ; ; Determine the characteristic contact point Contact points with features The straight line With the straight line perpendicular bisector Then the perpendicular bisector With a straight line The coordinates of the intersection point for: ; ; A straight line can be expressed by its slope as follows: , Represents a straight line The change in axis value straight line The change in axis values, and two mutually perpendicular straight lines. slope With a straight line slope satisfy Then the straight line perpendicular bisector of a line satisfy: ; in, Represents the perpendicular bisector The coordinates of the points on the surface; based on this, the points of contact with the features are determined. Contact points with features midpoint perpendicular bisector It can be represented as: ; Similarly, straight lines perpendicular bisector of a line satisfy: ; in, Represents the perpendicular bisector The coordinates of the points on the surface; based on this, the points of contact with the features are determined. Contact points with features midpoint perpendicular bisector It can be represented as: ; two perpendicular bisectors and The intersection point is the center point of the shaft hole, which is determined by connecting two perpendicular bisectors. and The corresponding equations of the two straight lines yield the coordinates of the center point of the shaft hole in the center detection reference coordinate system. for: ; ; in, Indicates characteristic contact point Contact points with features The line containing and Its perpendicular bisector The ordinate of the intersection point; Indicates characteristic contact point Contact points with features The straight line Its perpendicular bisector The x-coordinate of the intersection point; Indicates characteristic contact point Contact points with features The straight line The line and its perpendicular bisector The ordinate of the intersection point; Indicates characteristic contact point Contact points with features The straight line The line and its perpendicular bisector The x-coordinate of the intersection point; By combining the homogeneous transformation matrix from the central detection reference coordinate system to the world coordinate system, the spatial position of the shaft hole center point in the world coordinate system is obtained.

[0031] Preferably, in step 4 of the above method, the dual arms of the dual-arm robot are controlled to perform axial insertion motion and radial compliance adjustment of the shaft hole based on the dual-arm task priority compliance controller in the following manner: Step 41: Define the axial insertion motion as the primary task and the radial compliance adjustment as the secondary task, and establish the corresponding expression for the desired joint acceleration. Step 42: Utilize the decoupling characteristics of the dual-arm task in joint space to simplify the expression for the desired joint acceleration; Step 43: Analyze the relationship between the primary and secondary tasks in the assembly process of the shaft hole of the dual-arm robot, and derive the joint position commands applicable to the actual dual-arm robot control system to obtain the dual-arm cooperative compliant control strategy. Step 44: Based on the dual-arm cooperative compliant control strategy, control the dual arms of the dual-arm robot to perform coordinated execution of axial insertion motion and radial compliant adjustment.

[0032] Preferably, in step 41 of the above method, the axial insertion motion is defined as the primary task, the radial compliance adjustment is defined as the secondary task, and a corresponding expression for the desired joint acceleration is established, including: Axial insertion motion is defined as the primary task, and radial compliance adjustment is defined as the secondary task. Based on the coupling relationship between these two tasks in joint space, a task priority control method based on null space projection is adopted to construct a dual-arm cooperative control law at the acceleration level. The desired joint acceleration of this dual-arm cooperative control law is... The expression is: ; in, and These represent the main task variables. and secondary task variables The corresponding Jacobian matrix; and These represent the main task variables. and secondary task variables Acceleration in the task space; Represents the Moore–Penrose generalized inverse. Representing the Jacobian matrix Moore–Penrose generalized inverse, Representing the Jacobian matrix Moore–Penrose generalized inverse; The null projection operator corresponding to the main task. Represents the identity matrix; In step 42, the expression for the desired joint acceleration is simplified by utilizing the decoupling characteristics of the dual-arm task in joint space, including: By assigning axial insertion motion and radial compliance adjustment to different robotic arms, structural decoupling of the primary and secondary tasks in joint space is achieved. Under this task allocation strategy, the Jacobian matrix of the secondary task variables... Generalized inverse of the main task Coupling terms of the sub-task acting on different joint subspaces Ideally, it can be approximated as zero; therefore, the desired joint acceleration is... Simplified to: ; In step 43, the relationship between the primary and secondary tasks in the assembly process of the dual-arm robot's shaft holes is analyzed in the following manner, and the joint position commands applicable to the actual dual-arm robot control system are derived to obtain the dual-arm cooperative compliant control strategy, including: Within the dual-arm task-priority control framework, the right robotic arm of the dual-arm robot is defined as the main task execution arm, used to perform axial insertion motion along the axis of the shaft hole. This axial insertion motion employs a position control strategy based on PD in Cartesian space. The acceleration of the pose error at the end effector of the right robotic arm of the dual-arm robot is also considered. Represented as: ; in, , and All coordinates are referenced to the right robotic arm's task coordinate system. , These represent the pose error of the right robotic arm's end effector and the velocity of the pose error of the right robotic arm's end effector, respectively. and These are symmetric positive definite gain matrices; Task space acceleration corresponding to the main task Depend on This is obtained by selecting a matrix mapping, i.e.: ; To ensure that the top mold held by the right robotic arm moves only along the right robotic arm's task coordinate system Movement along the Z-axis, main task selection matrix Defined as: ; in, Describes the constructor for a diagonal matrix; While the right robotic arm performs the primary task of axial insertion, the left robotic arm of the dual-arm robot acts as a secondary task arm, used to adjust the radial contact force between the top mold and the inner wall of the cylinder's axial hole. This process employs a compliant controller. for: ; ; in, and These represent the desired pose of the parallel two-finger gripper at the end of the robotic arm and the corresponding end contact force during assembly. Expected pose under action; This indicates the pose error of the parallel two-finger gripper at the end of the robotic arm. and These represent the pose error velocity and pose error acceleration of the parallel two-finger gripper at the end of the robotic arm, respectively. It is the absolute value of the end contact force used to characterize the contact strength; , and All are diagonal matrices, representing equivalent mass, damping, and stiffness, respectively. This is a correction matrix used to adaptively modulate the response amplitude of the dual-arm robot system in order to accurately eliminate orientation errors; When the aforementioned compliant controller is applied to the left robotic arm performing the secondary task, the positional error acceleration of the parallel two-finger gripper at the end of the left robotic arm... Represented as: ; in, The end contact force of the parallel two-finger gripper at the end of the left robotic arm; , These represent the pose error of the left robotic arm end effector and the velocity of the pose error of the left robotic arm end effector, respectively. The secondary task performed by the left robotic arm only applies to the coordinate system of the left robotic arm task. The radial direction represents the task space acceleration corresponding to the sub-task. The positional error acceleration of the parallel two-finger gripper at the end of the left robotic arm It is obtained by selecting the matrix, that is: ; Among them, the sub-task selection matrix Defined as: ; in, Describes the constructor for a diagonal matrix; Within the task priority framework described above, the task space acceleration is based on the primary and secondary tasks. and The expected joint acceleration of the dual-arm robot system at the acceleration level is derived. The desired joint acceleration is discretized using a second-order forward integral to obtain the joint position quantity that can be sent to the bottom-level controller of the dual-arm robot. The expression is: ; in, To control the cycle; and These are the desired joint angle and desired joint velocity obtained from the reference trajectory, respectively. Step 44: Based on the joint position quantities of the dual-arm robot's underlying controller, which serve as the joint position commands for the actual dual-arm robot control system obtained in Step 43, control the right robotic arm of the dual-arm robot to perform an axial insertion motion along the axis of the shaft hole, while the left robotic arm simultaneously performs radial compliant adjustment. Through this dual-arm cooperative compliant control strategy, the coordinated execution of the axial insertion motion and the radial compliant adjustment is achieved.

[0033] This invention also provides a processing apparatus, comprising: At least one memory for storing one or more programs; At least one processor is capable of executing one or more programs stored in the memory, such that when the processor executes one or more programs, the processor can implement the method of the present invention.

[0034] The present invention further provides a readable storage medium storing a computer program that, when executed by a processor, can implement the method described in the present invention.

[0035] In summary, the control method provided by the embodiments of the present invention, through edge contact-based shaft hole pose recognition, uses end force and torque information to identify the edge of the mold surface and the hole position, providing reliable pose guidance for the initial stage of shaft hole assembly; at the same time, by designing a task-priority-based dual-arm compliant controller, the contact force and torque are dynamically adjusted within the priority task space, quickly correcting posture errors and reducing control complexity, realizing high-precision compliant assembly of infrared tablet molds under weak constraint conditions, and effectively solving the problem of high-precision assembly of tablet molds in chemical infrared characterization scenarios.

[0036] To more clearly demonstrate the technical solution and its effects provided by the present invention, the following detailed description of the solution provided by the embodiments of the present invention is provided with reference to specific examples.

[0037] Example 1 like Figures 1 to 5 As shown, this embodiment provides a control method for assembling the shaft hole of a tableting mold using a dual-arm robot. It is a collaborative strategy for assembling the shaft hole of a tableting mold used in chemical infrared characterization, aimed at improving the stability and success rate of the dual-arm robot in high-precision assembly tasks. The equipment involved in this method specifically includes: Dual-arm robot, infrared tablet pressing mold, six-dimensional torque sensor, and parallel two-finger gripper; The infrared pressing mold consists of a top mold 30, a cylinder 20, and a base, all made of steel (ASSAB+17). The diameter and depth of the shaft hole 40 are 10mm and 30mm respectively, with a 1.5mm chamfer around the hole opening. The force transmission rod below the top mold does not include a chamfer. During mold assembly, the right robotic arm of the dual-arm robot uses a two-finger gripper to hold the assembly formed by the cylinder and the base, while the left robotic arm of the dual-arm robot holds the top mold using the two-finger gripper.

[0038] The six-dimensional torque sensor is installed at the end of each robotic arm of the dual-arm robot and connected to a parallel two-finger gripper. The parallel two-finger gripper is installed on the two robotic arms of the dual-arm robot, and the mold is fixed by the end two-finger gripper. All of the robotic arms are multi-degree-of-freedom manipulators; The dual-arm robot is communicatively connected to the parallel two-finger gripper and consists of a robotic arm and a parallel two-finger gripper mounted at its end.

[0039] To address the high-precision assembly problem of molds in infrared characterization tablet pressing experiments, this invention proposes a collaborative assembly strategy using a dual-arm robot. To reduce alignment errors in the initial assembly stage, an edge-contact-based pose recognition method is first employed to achieve online estimation of the shaft hole posture and center position through multi-point contact detection. Subsequently, a dual-arm task-priority compliant controller based on a Gaussian mixture model (GMM) is designed to establish the mapping relationship between contact forces and torques during assembly and different pose error states, and this relationship is incorporated into the compliant control framework to achieve fine adjustment of the shaft hole pose error. Simultaneously, a priority projection operator is used to effectively decouple axial insertion motion and radial compliant adjustment within the task space, thereby reducing mutual interference between primary and secondary tasks and improving the stability and reliability of the assembly process.

[0040] Figure 5 The overall control process of a dual-arm robot performing shaft and hole assembly tasks is demonstrated.

[0041] The method of the present invention specifically includes the following steps: Step 1: The dual-arm robot estimates the orientation of the shaft hole by jointly modeling the contact state and geometric constraints. This includes the following steps: Step 11: Control the fingertips of the parallel two-finger gripper installed at the end of the left robotic arm 10 of the dual-arm robot to contact the upper surface of the cylinder 20. When the force feedback signal at the end of the left robotic arm reaches a preset threshold, record the position of the parallel two-finger gripper at the end of the left robotic arm in the world coordinate system {W} at the corresponding moment. Figure 2 As shown, by collecting no fewer than three contact feature points on the upper surface of the cylinder 20, a planar model of the upper surface of the cylinder can be performed.

[0042] Step 12, when calculating the normal vector of the upper surface of the cylinder, the n contact feature points collected are... Plane fitting is performed using the least squares method, and each contact feature point is represented as... First, the centroid of the contact feature point set is... Defined as: ; Subsequently, a decentralized matrix is ​​constructed based on each contact feature point. : ; And by a decentralized matrix Construct the covariance matrix : ; For covariance matrix Perform eigenvalue decomposition (SVD), and take the eigenvector corresponding to the smallest eigenvalue as the unit normal vector of the upper surface of the cylinder. : ; in, Describes the function that minimizes the value. The independent variable that achieves its maximum value; Represents a unit direction vector in three-dimensional space. Represents the unit direction vector Size, Represents the set of real numbers; This indicates the magnitude of the variance at the contact point in that direction. The direction corresponding to the minimum variance is the normal vector of the upper surface of the cylinder.

[0043] Step 13: Since the axis of the shaft hole is aligned with the direction of the normal vector on the upper surface of the cylinder, the spatial orientation of the shaft hole can be determined using the estimated plane normal vector. The orientation direction is expressed in Euler angles as follows: Pitch angle in Euler angles : ; Roll angle in Euler angles : ; Yaw angle in Euler angles : ; in, Represents the arctangent function; , and They represent the unit normal vectors respectively. The components in the x-axis, y-axis, and z-axis directions of the reference coordinate system.

[0044] Step 2: After obtaining the axis direction of the shaft hole, the center point position of the shaft hole is further estimated based on the shaft hole orientation.

[0045] Step 21, as follows Figure 3 As shown in the left figure, to ensure geometric consistency in feature point acquisition, during the contact between the gripper of the parallel two-finger gripper at the end of the left robotic arm 10 and the side wall of the mold cylinder 20, the gripper's posture is controlled to always remain consistent with the Euler angles obtained in step 13, and the axis of the shaft hole is ensured to be perpendicular to the plane formed by the acquired contact points. Specifically, when the gripper closes and its end fits against the upper surface of the cylinder, this end pose is defined as the central detection reference coordinate system {T}. Subsequently, the gripper opens and moves a fixed distance along the positive z-axis of the {T} coordinate system, and then moves within the xoy plane of {T} to acquire three feature contact points. , , .

[0046] Step 22: By controlling the end effector gripper to contact the cylinder sidewall, when the end effector force feedback signal reaches a preset threshold, record the corresponding end effector spatial pose. To improve the robustness of the center point estimation, first collect e sidewall contact points, and then select any 3 characteristic contact points to form... There are several combination methods. Geometric operations are performed on each combination to solve for the coordinates of the center point of the shaft hole. Finally, the arithmetic mean of the center point results obtained from all combinations is taken as the estimated result of the center point of the shaft hole.

[0047] Step 23: When calculating the position of the shaft hole center point, use the three characteristic contact points obtained in the center detection reference coordinate system. , and Determine the characteristic contact points Contact points with features The straight line With the straight line perpendicular bisector Then the perpendicular bisector With a straight line The coordinates of the intersection point for: ; ; Determine the characteristic contact point Contact points with features The straight line With the straight line perpendicular bisector Then the perpendicular bisector With a straight line The coordinates of the intersection point for: ; ; Considering that a straight line can be expressed by its slope as Represents a straight line The change in axis value straight line The change in axis values, and two mutually perpendicular straight lines. slope With a straight line slope satisfy Then the straight line perpendicular bisector of a line satisfy: ; in, Represents the perpendicular bisector The coordinates of the points on the surface; based on this, the points of contact with the features are determined. Contact points with features midpoint perpendicular bisector It can be represented as: ; Similarly, straight lines perpendicular bisector of a line satisfy: ; in, Represents the perpendicular bisector The coordinates of the points on the surface; based on this, the points of contact with the features are determined. Contact points with features midpoint perpendicular bisector It can be represented as: ; two perpendicular bisectors and The intersection point is the center point of the shaft hole, which is determined by connecting two perpendicular bisectors. and The corresponding equations of the two straight lines yield the coordinates of the center point of the shaft hole in the center detection reference coordinate system. for: ; ; in, Indicates characteristic contact point Contact points with features The line containing and Its perpendicular bisector The ordinate of the intersection point; Indicates characteristic contact point Contact points with features The straight line Its perpendicular bisector The x-coordinate of the intersection point; Indicates characteristic contact point Contact points with features The straight line The line and its perpendicular bisector The ordinate of the intersection point; Indicates characteristic contact point Contact points with features The straight line The line and its perpendicular bisector The x-coordinate of the intersection point; By combining the homogeneous transformation matrix from the central detection reference coordinate system {T} to the world coordinate system {W}, the spatial position of the shaft hole center point CC in the world coordinate system {W} can be obtained.

[0048] Step 3: Based on the shaft hole pose information obtained by the edge contact algorithm, control the left robotic arm of the dual-arm robot to move the top mold to directly above the shaft hole of the cylinder held by the right robotic arm, and ensure that the Z-axis of the force / torque sensor is collinear with the axis of the top mold by using a gripper gripping method, so that the dual-arm robot system enters the initial assembly state.

[0049] Step 4: Based on the dual-arm task priority compliance controller, control the dual arms of the dual-arm robot to perform axial insertion motion and radial compliance adjustment of the shaft hole.

[0050] Step 41: Define the axial insertion motion as the primary task and the radial compliance adjustment as the secondary task. Considering the coupling relationship between the two types of tasks in joint space, a task priority control method based on null space projection is adopted. A dual-arm cooperative control law is constructed at the acceleration level, and its expected joint acceleration is expressed as: ; in, and These represent the main task variables. and secondary task variables The corresponding Jacobian matrix; and These represent the main task variables. and secondary task variables Acceleration in the task space; Represents the Moore–Penrose generalized inverse. Representing the Jacobian matrix Moore–Penrose generalized inverse, Representing the Jacobian matrix Moore–Penrose generalized inverse; The null projection operator corresponding to the main task. Represents the identity matrix.

[0051] Step 42: By assigning the axial insertion motion and radial compliance adjustment to different robotic arms, the primary and secondary tasks are structurally decoupled in joint space. Under this task allocation strategy, the Jacobian matrix of the secondary task variables... Generalized inverse of the main task Coupling terms of the sub-task acting on different joint subspaces Ideally, it can be approximated as zero; therefore, the desired joint acceleration is... It can be simplified to: ; Step 43: Under the dual-arm task priority control framework, the right robotic arm is defined as the main task execution arm, used to perform insertion motion along the axis of the shaft hole. The insertion motion employs a PD-based position control strategy in Cartesian space, and its right robotic arm end-effector pose error acceleration is expressed as: ; in, , and All with Figure 4 The right robotic arm task coordinate system shown For reference, , These represent the pose error of the right robotic arm's end effector and the velocity of the pose error of the right robotic arm's end effector, respectively. and These are symmetric positive definite gain matrices.

[0052] Task space acceleration corresponding to the main task Depend on This is obtained by selecting a matrix mapping, i.e.: ; To ensure that the top mold held by the right robotic arm moves only along the right robotic arm's task coordinate system Movement along the Z-axis, main task selection matrix Defined as: ; in, Describes the constructor for a diagonal matrix; While the right robotic arm performs the main insertion task, the left robotic arm acts as an auxiliary actuator to adjust the radial contact force between the top mold and the inner wall of the cylinder's shaft hole. This process employs a compliant controller. It can be designed as: ; ; in, and These represent the desired pose of the parallel two-finger gripper at the end of the left robotic arm and the contact force at the end during assembly. The expected pose under the action, with subscript parameters This indicates the parameters corresponding to the left robotic arm, with subscripts. parameters This represents the parameters corresponding to the right robotic arm, such as: This represents the desired pose of the parallel two-finger gripper at the end of the left robotic arm; This represents the desired pose of the parallel two-finger gripper at the end of the right robotic arm; This indicates the measured end-effector contact force during the assembly process of the parallel two-finger gripper at the end of the left robotic arm. Expected pose under action; This indicates the expected pose of the parallel two-finger gripper at the end of the right robotic arm; This indicates the pose error of the parallel two-finger gripper at the end effector of the robotic arm. This indicates the pose error of the parallel two-finger gripper at the end of the left robotic arm. This indicates the pose error of the parallel two-finger gripper at the end of the right robotic arm; and These represent the pose error velocity and pose error acceleration of the parallel two-finger gripper at the end of the robotic arm, respectively. This indicates the pose error of the parallel two-finger gripper at the end of the left robotic arm. Acceleration This indicates the pose error of the parallel two-finger gripper at the end of the right robotic arm. Acceleration; It is the absolute value of the end contact force used to characterize the contact strength; , and All are diagonal matrices, representing equivalent mass, damping, and stiffness, respectively. This is a correction matrix used to adaptively modulate the response amplitude of the dual-arm robot system in order to accurately eliminate orientation errors.

[0053] Therefore, as a secondary task, the pose error acceleration of the parallel two-finger gripper at the end of its left robotic arm is... It can be represented as: ; in, The end contact force of the parallel two-finger gripper at the end of the left robotic arm; , These represent the pose error of the left robotic arm end effector and the velocity of the pose error of the left robotic arm end effector, respectively.

[0054] Considering that the left robotic arm's secondary task only applies to... Figure 4 The left robotic arm's task coordinate system is shown. The radial direction represents the task space acceleration corresponding to the sub-task. The positional error acceleration of the parallel two-finger gripper at the end of the left robotic arm. It is obtained by selecting the matrix, that is: ; Among them, the sub-task selection matrix Defined as: ; in, Describes the constructor for a diagonal matrix; Within the task priority framework described above, the task space acceleration is based on the primary and secondary tasks. and The expected joint acceleration of the dual-arm robot system at the acceleration level is derived. Considering that practical robot control systems typically employ discrete-time methods, this invention uses second-order forward integrals to discretize joint accelerations, thereby obtaining joint position quantities that can be sent to the underlying controller of the dual-arm robot. Its expression is: ; in, To control the cycle; and These represent the desired joint angle and desired joint velocity obtained from the reference trajectory of the robotic arm, respectively. This represents the desired joint angle obtained from the reference trajectory of the left robotic arm. This represents the desired joint acceleration obtained from the reference trajectory of the left robotic arm. This represents the desired joint angle obtained from the reference trajectory of the right robotic arm. This represents the desired joint acceleration obtained from the reference trajectory of the right robotic arm.

[0055] Step 44: The right robotic arm performs an insertion motion along the axis of the shaft hole, while the left robotic arm simultaneously performs radial compliance adjustment. Through the dual-arm task-priority compliance control strategy, the insertion motion and radial compliance adjustment are executed in a coordinated manner.

[0056] Step 5: When the right robotic arm moves along the axis of the shaft hole to the set distance and reaches the given insertion depth, control the left robotic arm gripper to open and release the top mold, thereby completing the assembly task of the infrared tablet press mold.

[0057] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0058] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims. The information disclosed in the background section is intended only to enhance the understanding of the overall background technology of the present invention and should not be construed as an admission or implication in any way that such information constitutes prior art known to those skilled in the art.

Claims

1. A control method for the shaft hole of a tablet press mold assembled by a dual-arm robot, characterized in that, The system is used to control a dual-arm robot to grip the top mold of an infrared tablet press mold and the assembly consisting of a cylinder and a base, and to assemble the top mold into the shaft hole of the cylinder, including: Step 1: By jointly modeling the contact state and geometric constraints between the dual-arm robot and the cylinder, the orientation of the shaft hole on the cylinder is obtained. In Step 1, the orientation of the shaft hole on the cylinder is obtained by jointly modeling the contact state and geometric constraints between the dual-arm robot and the cylinder, including: Step 11: Control the fingertips of the parallel two-finger gripper at the end of the left robotic arm of the dual-arm robot to make contact with the upper surface of the cylinder where the shaft hole is located, and collect no less than three contact feature points on the upper surface of the cylinder. Step 12: Perform plane fitting on the collected contact feature points using the least squares method to calculate the plane normal vector of the upper surface of the cylinder. Step 13: Determine the spatial orientation of the shaft hole on the cylinder based on the obtained plane normal vector; Step 2: Based on the obtained shaft hole orientation, estimate the position of the center point of the shaft hole; In step 2, the center point position of the shaft hole is estimated based on the obtained shaft hole orientation in the following manner: Step 21: Control the gripper posture of the parallel two-finger gripper at the end of the left robotic arm of the dual-arm robot to be consistent with the posture of the shaft hole, and collect three feature contact points on the side wall of the cylinder. Step 22: Combine the characteristic contact points on the sidewall collected in Step 21 into a characteristic point combination, calculate and solve the coordinates of the shaft hole center point of each group of characteristic point combinations, and take the average value of the shaft hole center point coordinates calculated by each group of characteristic point combinations as the estimated shaft hole center point coordinates. Step 23: Determine the position of the center point of the shaft hole based on the coordinates of the center point of the shaft hole obtained in Step 22; Step 3: Based on the obtained shaft hole posture and the center point position of the shaft hole, control the left robotic arm of the dual-arm robot to move the top mold of the infrared pressing mold to the shaft hole position of the cylinder held by the right robotic arm to enter the initial assembly state. Step 4: Based on the dual-arm task priority compliance controller, control the dual arms of the dual-arm robot to perform axial insertion motion and radial compliance adjustment of the shaft hole; Step 5: When it is determined that the right robotic arm of the dual-arm robot has moved a given distance along the axis of the shaft hole and reached the preset insertion depth, the left robotic arm of the dual-arm robot is controlled to release the top mold, thus completing the assembly of the infrared pressing mold.

2. The control method for the shaft hole of the tablet pressing mold assembled by a dual-arm robot according to claim 1, characterized in that, In step 11, the gripper tips of the parallel two-finger gripper at the end of the left robotic arm of the dual-arm robot are controlled to contact the upper surface of the cylinder where the shaft hole is located, and at least three contact feature points on the upper surface of the cylinder are collected, including: When the fingertips of the parallel two-finger gripper at the end of the left robotic arm of the dual-arm robot come into contact with the upper surface of the cylinder, and the force feedback signal at the end of the left robotic arm reaches a preset threshold, the position of the parallel two-finger gripper at the end of the left robotic arm in the world coordinate system at the corresponding moment is recorded. This position is the contact feature point position between the fingertips of the parallel two-finger gripper at the end of the left robotic arm and the upper surface of the cylinder. In step 12, the collected contact feature points are fitted using the least squares method to obtain the plane normal vector of the upper surface of the cylinder, including: Step 121, for the collected n contact feature points The least squares method is used for plane fitting. To indicate the index of the contact feature points, first, the centroid of the contact feature point set is... Defined as: ； Subsequently, a decentralized matrix is ​​constructed based on each contact feature point. ,for: ； Among them, superscript Represents the transpose of a matrix; Represents the set of real numbers; Decentralized matrix Construct the covariance matrix ,for: ； The covariance matrix is ​​analyzed through singular value decomposition. Eigenvalue decomposition yields eigenvectors, and the eigenvector corresponding to the smallest eigenvalue is taken as the unit normal vector of the upper surface of the cylinder. : ； in, Describes the function that minimizes the value. The independent variable that achieves its maximum value; Represents a unit direction vector in three-dimensional space. Represents the set of real numbers. Represents the unit direction vector Size; This represents the variance of the contact feature point in that direction, and the direction with the minimum variance is the plane normal vector of the upper surface of the cylinder. In step 13, the spatial orientation of the shaft hole on the cylinder is determined based on the obtained plane normal vector in the following manner: Since the direction of the shaft hole axis is consistent with the direction of the plane normal vector on the upper surface of the cylinder, the spatial attitude of the shaft hole is determined using the obtained plane normal vector. This spatial attitude direction is expressed in Euler angle form as follows: Pitch angle in Euler angles : ; Roll angle in Euler angles : ; Yaw angle in Euler angles : ; in, Represents the arctangent function; , and They represent the unit normal vectors respectively. The components in the x, y, and z directions of the reference coordinate system.

3. The control method for the shaft hole of the tablet pressing mold assembled by a dual-arm robot according to claim 1, characterized in that, In step 21, the dual-arm robot is controlled in the following manner to align the gripper posture of the end effector parallel two-finger gripper with the shaft hole posture, and three characteristic contact points on the side wall of the cylinder are collected, including: During the process of controlling the contact between the gripper of the parallel two-finger gripper at the end of the dual-arm robot and the side wall of the cylinder, the gripper is controlled to make contact with the side wall of the cylinder. When the end force feedback signal reaches the preset threshold, the spatial pose of the corresponding parallel two-finger gripper is recorded. The control ensures that the posture of the gripper of the parallel two-finger gripper is always consistent with the Euler angle obtained in step 13, and ensures that the axis direction of the shaft hole is perpendicular to the plane formed by the collected feature contact points. When the gripper closes and its end is attached to the upper surface of the cylinder, the gripper's position is defined as the central detection reference coordinate system. Then the gripper opens and moves a fixed distance along the positive z-axis of the central detection reference coordinate system. Then it moves in the xoy plane of the central detection reference coordinate system to obtain e feature contact points. Any three feature contact points are selected from the e feature contact points. In step 22, the characteristic contact points collected in step 21 are combined into contact point combinations in the following manner, the coordinates of the shaft hole center point of each contact point combination are calculated, and the average value of the shaft hole center point coordinates calculated for each contact point combination is taken as the estimated shaft hole center point coordinates, including: Combine the three feature contact points selected in step 21 into For each combination of contact points, geometric operations are performed to solve for the coordinates of the center point of the shaft hole. The arithmetic mean of the center point coordinates obtained from all the contact point combinations is taken as the estimated coordinates of the center point of the shaft hole.

4. The control method for the shaft hole of the tablet pressing mold assembled by a dual-arm robot according to claim 3, characterized in that, In step 23, the position of the center point of the shaft hole is determined based on the coordinates of the center point of the shaft hole obtained in step 22, including: When calculating the position of the center point of the shaft hole, three characteristic contact points obtained in the center detection reference coordinate system are used. , and Determine the characteristic contact points Contact points with features The straight line With the straight line perpendicular bisector Then the perpendicular bisector With a straight line The coordinates of the intersection point for: ； ； Determine the characteristic contact point Contact points with features The straight line With the straight line perpendicular bisector Then the perpendicular bisector With a straight line The coordinates of the intersection point for: ； ； A straight line can be expressed by its slope as follows: , Represents a straight line The change in axis value straight line The change in axis values, and two mutually perpendicular straight lines. slope With a straight line slope satisfy Then the straight line perpendicular bisector of a line satisfy: ； in, Represents the perpendicular bisector The coordinates of the points on the surface; based on this, the points of contact with the features are determined. Contact points with features midpoint perpendicular bisector It can be represented as: ； Similarly, straight lines perpendicular bisector of a line satisfy: ； in, Represents the perpendicular bisector The coordinates of the points on the surface; based on this, the points of contact with the features are determined. Contact points with features midpoint perpendicular bisector It can be represented as: ； two perpendicular bisectors and The intersection point is the center point of the shaft hole, which is determined by connecting two perpendicular bisectors. and The corresponding equations of the two straight lines yield the coordinates of the center point of the shaft hole in the center detection reference coordinate system. for: ； ； in, Indicates characteristic contact point Contact points with features The line containing and Its perpendicular bisector The ordinate of the intersection point; Indicates characteristic contact point Contact points with features The straight line Its perpendicular bisector The x-coordinate of the intersection point; Indicates characteristic contact point Contact points with features The straight line Its perpendicular bisector The ordinate of the intersection point; Indicates characteristic contact point Contact points with features The straight line Its perpendicular bisector The x-coordinate of the intersection point; By combining the homogeneous transformation matrix from the central detection reference coordinate system to the world coordinate system, the spatial position of the shaft hole center point in the world coordinate system is obtained.

5. The control method for the shaft hole of the tablet pressing mold assembled by a dual-arm robot according to any one of claims 1-2, characterized in that, In step 4, the dual arms of the dual-arm robot are controlled to perform axial insertion motion and radial compliance adjustment of the shaft hole based on the dual-arm task priority compliance controller in the following manner: Step 41: Define the axial insertion motion as the primary task and the radial compliance adjustment as the secondary task, and establish the corresponding expression for the desired joint acceleration. Step 42: Utilize the decoupling characteristics of the dual-arm task in joint space to simplify the expression for the desired joint acceleration; Step 43: Analyze the relationship between the primary and secondary tasks in the assembly process of the shaft hole of the dual-arm robot, and derive the joint position commands applicable to the actual dual-arm robot control system to obtain the dual-arm cooperative compliant control strategy. Step 44: Based on the dual-arm cooperative compliant control strategy, control the dual arms of the dual-arm robot to perform coordinated execution of axial insertion motion and radial compliant adjustment.

6. The control method for the shaft hole of the tablet pressing mold assembled by a dual-arm robot according to claim 5, characterized in that, In step 41, the axial insertion motion is defined as the primary task, the radial compliance adjustment is defined as the secondary task, and the corresponding expression for the desired joint acceleration is established, including: Axial insertion motion is defined as the primary task, and radial compliance adjustment is defined as the secondary task. Based on the coupling relationship between these two tasks in joint space, a task priority control method based on null space projection is adopted to construct a dual-arm cooperative control law at the acceleration level. The desired joint acceleration of this dual-arm cooperative control law is... The expression is: ； in, and These represent the main task variables. and secondary task variables The corresponding Jacobian matrix; and These represent the main task variables. and secondary task variables Acceleration in the task space; Represents the Moore–Penrose generalized inverse. Representing the Jacobian matrix Moore–Penrose generalized inverse, Representing the Jacobian matrix Moore–Penrose generalized inverse; The null projection operator corresponding to the main task. Represents the identity matrix; In step 42, the expression for the desired joint acceleration is simplified by utilizing the decoupling characteristics of the dual-arm task in joint space, including: By assigning axial insertion motion and radial compliance adjustment to different robotic arms for execution, structural decoupling of the primary and secondary tasks in joint space is achieved, and the Jacobian matrix of the secondary task variables is obtained. Generalized inverse of the main task Coupling terms of the sub-task acting on different joint subspaces Ideally, it can be approximated as zero; therefore, the desired joint acceleration is... Simplified to: ； In step 43, the relationship between the primary and secondary tasks in the assembly process of the dual-arm robot's shaft holes is analyzed in the following manner, and the joint position commands applicable to the actual dual-arm robot control system are derived to obtain the dual-arm cooperative compliant control strategy, including: Within the dual-arm task-priority control framework, the right robotic arm of the dual-arm robot is defined as the main task execution arm, used to perform axial insertion motion along the axis of the shaft hole. This axial insertion motion employs a position control strategy based on PD in Cartesian space. The acceleration of the pose error at the end effector of the right robotic arm of the dual-arm robot is also considered. Represented as: ； in, , and All coordinates are referenced to the right robotic arm's task coordinate system. , These represent the pose error of the right robotic arm's end effector and the velocity of the pose error of the right robotic arm's end effector, respectively. and These are symmetric positive definite gain matrices; Task space acceleration corresponding to the main task Depend on This is obtained by selecting a matrix mapping, i.e.: ； To ensure that the top mold held by the right robotic arm moves only along the right robotic arm's task coordinate system Movement along the Z-axis, main task selection matrix Defined as: ； in, Describes the constructor for a diagonal matrix; While the right robotic arm performs the primary task of axial insertion, the left robotic arm of the dual-arm robot acts as a secondary task arm, used to adjust the radial contact force between the top mold and the inner wall of the cylinder's axial hole. This process employs a compliant controller. for: ； ； in, and These represent the desired pose of the parallel two-finger gripper at the end of the robotic arm and the end-effector contact force during assembly. Expected pose under action; This indicates the pose error of the parallel two-finger gripper at the end of the robotic arm. and These represent the pose error velocity and pose error acceleration of the parallel two-finger gripper at the end of the robotic arm, respectively. It is the absolute value of the end contact force used to characterize the contact strength; , and All are diagonal matrices, representing equivalent mass, damping, and stiffness, respectively. This is a correction matrix used to adaptively modulate the response amplitude of the dual-arm robot system in order to accurately eliminate orientation errors; End-effector pose error acceleration of the left robotic arm performing the sub-task Represented as: ； in, The end contact force of the parallel two-finger gripper at the end of the left robotic arm; , These represent the pose error of the left robotic arm end effector and the velocity of the pose error of the left robotic arm end effector, respectively. The secondary task performed by the left robotic arm only applies to the coordinate system of the left robotic arm task. The radial direction represents the task space acceleration corresponding to the sub-task. The positional error acceleration of the parallel two-finger gripper at the end of the left robotic arm It is obtained by selecting the matrix, that is: ； Among them, the sub-task selection matrix Defined as: ； in, Describes the constructor for a diagonal matrix; Based on the task space acceleration of the primary and secondary tasks and The expected joint acceleration of the dual-arm robot system at the acceleration level is derived. The desired joint acceleration is discretized using a second-order forward integral to obtain the joint position quantity that can be sent to the bottom-level controller of the dual-arm robot. The expression is: ； in, To control the cycle; and These represent the desired joint angle and desired joint velocity obtained from the reference trajectory, respectively. Step 44: Based on the joint position quantities of the dual-arm robot's underlying controller, which serve as the joint position commands for the actual dual-arm robot control system obtained in Step 43, control the right robotic arm of the dual-arm robot to perform an axial insertion motion along the axis of the shaft hole, while the left robotic arm simultaneously performs radial compliant adjustment. Through this dual-arm cooperative compliant control strategy, the coordinated execution of the axial insertion motion and the radial compliant adjustment is achieved.

7. A processing device, characterized in that, include: At least one memory for storing one or more programs; At least one processor is capable of executing one or more programs stored in the memory, such that when the one or more programs are executed by the processor, the processor can perform the method according to any one of claims 1-6.

8. A readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it can implement the method described in any one of claims 1-6.

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