A Smart Assembly Method Based on Serial-Parallel Dual-Robot Collaboration

Abstract

This invention discloses an intelligent assembly method based on the collaboration of parallel and serial dual robots, solving the problems of difficulty in achieving compliant control in the assembly process of aerospace equipment in the prior art, and the lack of high automation and universality in the assembly system. The method includes: the end effector of the parallel robot clamps a first component to be assembled and moves the first component to be assembled to a first preset assembly pose; the end effector of the serial robot clamps a second component to be assembled and moves the second component to be assembled to a second preset assembly pose; relative poses are obtained through a vision perception module; the parallel and serial robots move to the optimal assembly position according to the relative poses; the parallel robot adjusts the first optimal assembly position through a torque perception module to complete the intelligent assembly of the dual robots; it realizes the use of a combination of vision and force perception to effectively improve the automation level, work efficiency and compliance of the assembly of large components in unstructured dynamic environments.

Description

Technical Field

[0001] This invention relates to the field of automated assembly technology, and in particular to an intelligent assembly method based on the collaboration of serial and parallel dual robots. Background Technology

[0002] The aerospace industry is a crucial indicator of a nation's economy, defense capabilities, and industrialization level. Assembly is the final stage and a critical technological link in aerospace equipment manufacturing, accounting for approximately 50% of the total manufacturing cycle time and 30% of the total cost. Traditional assembly of large components typically employs a manual operation method of "visual inspection, shouting, and manual pushing," relying heavily on a large workforce and a limited amount of tooling equipment.

[0003] The main problems with existing technologies are that they require multiple people to work together, resulting in low assembly efficiency, high labor intensity, poor consistency in assembly quality, and the inability to guarantee compliance during the assembly process. Summary of the Invention

[0004] This invention provides an intelligent assembly method based on the collaboration of serial and parallel dual robots, which solves the problems in the existing technology of difficult to achieve compliant control in the assembly process of aerospace equipment, and the lack of high automation and universality of the assembly system. It realizes the use of vision and force perception combined assistance to effectively improve the automation level, work efficiency and compliance of large component assembly in unstructured dynamic environment.

[0005] This invention provides an intelligent assembly method based on the collaboration of serial and parallel dual robots, the method comprising:

[0006] The end effector of the parallel robot clamps the first component to be assembled and moves the first component to be assembled to a first preset assembly position; the end effector of the serial robot clamps the second component to be assembled and moves the second component to be assembled to a second preset assembly position.

[0007] The relative pose between the first component to be assembled and the second component to be assembled is obtained through a visual perception module.

[0008] The parallel robot and the serial robot move to the first optimal assembly position and the second optimal assembly position according to the relative pose.

[0009] The parallel robot adjusts the first optimal assembly position through the torque sensing module to complete the intelligent assembly of the two robots.

[0010] In one possible implementation, the visual perception module includes: a binocular camera, a target, and a first data processing module;

[0011] The binocular camera is mounted on the serial robot;

[0012] The target is set on the first component to be assembled;

[0013] The first data processing module is located on the server.

[0014] In one possible implementation, the torque sensing module includes: a sensor module and a second data processing module;

[0015] The sensor module is located at the translational joint of the parallel robot;

[0016] The second data processing module is located on the server.

[0017] In one possible implementation, obtaining the relative pose between the first component to be assembled and the second component to be assembled via a visual perception module includes:

[0018] The first coordinate position of the target in the camera coordinate system where the parallel robot is located is obtained through the target in the visual perception module;

[0019] Using the binocular camera in the visual perception module and the first coordinate position, the second coordinate position of the target in the target coordinate system where the binocular camera is located is obtained;

[0020] The transformation relationship between the camera coordinate system and the target coordinate system is determined using the calibration information of the binocular camera, the first coordinate position, and the second coordinate position.

[0021] The actual position coordinates of the target in the coordinate system of the end effector of the serial robot are obtained according to the transformation relationship.

[0022] The actual position coordinates are used as the relative pose.

[0023] In one possible implementation, the relationship between the first coordinate position and the actual position coordinates is expressed as follows:

[0024]

[0025] in, Let represent the rotation transformation matrix of the target coordinate system {A} relative to the coordinate system of the end effector of the serial robot. It is a translation vector; Indicates the actual position coordinates; Indicates the first coordinate position.

[0026] In one possible implementation, the parallel robot adjusts the first optimal assembly position through a torque sensing module to complete the dual-robot intelligent assembly, including:

[0027] Multiple measurement values ​​are obtained using multiple sensor modules in the torque sensing module;

[0028] The first force vector is obtained by calculating the multiple measured values ​​using a force transmission model;

[0029] The parallel robot's movement is controlled based on the first force vector, and the first optimal assembly position is adjusted to ensure that the first force vector does not exceed a preset value until the dual-robot intelligent assembly is completed.

[0030] In one possible implementation, the force transmission model is represented as:

[0031]

[0032] in, P F ext This indicates the force acting on the end effector of a parallel robot; P J kin F represents the Jacobian matrix of a parallel robot; q =(f1,f2,f3,f4,f5,f6) T This indicates the force measured by the sensor module; P F G Represents gravity; Represents the rotation matrix from the coordinate system of the end effector of the parallel robot to the base coordinate system of the parallel robot; p x sp Indicates the center of gravity position of the end effector of the parallel robot; F q0 This indicates the zero-position drift caused by platform deformation; This indicates the zero-position drift caused by changes in the position of the end effector; B g represents the gravitational acceleration in the parallel robot's coordinate system. B g = (0, 0, 9.81) T ;m p This indicates the quality of the parallel robot's motion platform.

[0033] In one possible implementation, the force transmission model is set up on a server.

[0034] In one possible implementation, the sensor module is a one-dimensional tension / pressure sensor.

[0035] One or more technical solutions provided in this invention have at least the following technical effects or advantages:

[0036] This invention provides an intelligent assembly method based on the collaboration of serial and parallel dual robots, which optimizes the aspects of high compliance, high efficiency and safety. It utilizes a combination of vision and force assistance to effectively improve the automation, work efficiency and compliance of large component assembly in unstructured dynamic environments. Attached Figure Description

[0037] Figure 1 A flowchart illustrating the steps of an intelligent assembly method based on the collaboration of two serial and parallel robots provided in an embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram of the force / torque sensing module provided in an embodiment of the present invention;

[0039] Figure 3 A schematic diagram of the visual perception module provided in an embodiment of the present invention;

[0040] Figure 4 An assembly flowchart provided for an embodiment of the present invention. Detailed Implementation

[0041] 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, not all, of the embodiments of 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 scope of protection of the present invention.

[0042] This invention provides an intelligent assembly method based on the collaboration of serial and parallel dual robots, such as... Figure 1 As shown, the method includes the following steps S101 to S104.

[0043] S101, the end effector of the parallel robot clamps the first component to be assembled and moves the first component to be assembled to the first preset assembly position, and the end effector of the serial robot clamps the second component to be assembled and moves the second component to be assembled to the second preset assembly position.

[0044] The end effectors of the parallel robot and the serial robot respectively clamp the first component to be assembled and the second component to be assembled, and move them to the first preset assembly pose and the second preset assembly pose.

[0045] S102, the relative pose between the first component to be assembled and the second component to be assembled is obtained through the visual perception module.

[0046] Specifically, in step S102, the visual perception module includes: a binocular camera, a target, and a first data processing module; the binocular camera is mounted on the serial robot; the target is mounted on the first component to be assembled; and the first data processing module is mounted on a server.

[0047] Specifically, in step S102, the relative pose between the first component to be assembled and the second component to be assembled is obtained through the visual perception module, including the following steps S1021 to S1025.

[0048] S1021, the first coordinate position of the target in the camera coordinate system where the parallel robot is located is obtained through the target in the visual perception module.

[0049] S1022, using the binocular camera in the visual perception module and the first coordinate position, the second coordinate position of the target in the target coordinate system where the binocular camera is located is obtained;

[0050] S1023, using the calibration information of the binocular camera, the first coordinate position, and the second coordinate position, determine the transformation relationship between the camera coordinate system and the target coordinate system;

[0051] S1024, Based on the transformation relationship, obtain the actual position coordinates of the target in the coordinate system of the end effector of the serial robot;

[0052] S1025, use the actual position coordinates as the relative pose.

[0053] For example, a binocular camera is installed on a serial robot, which, together with a first data processing module and a target placed on a first component to be assembled held by a parallel robot, forms a visual perception system to obtain the relative pose relationship between the two components to be assembled and to feed the data back to the first data processing module.

[0054] like Figure 2 The visual perception system shown consists of a binocular camera mounted on the serial robot, a first data processing module, and a target placed on the end effector of the parallel robot for gripping the first component to be assembled. The position of the target point in the target coordinate system {A} (X...) A ,Y A Z A The target point's position in the camera coordinate system is obtained through visual measurement, and the transformation relationship between the camera coordinate system and the coordinate system of the serial robot's end effector is obtained through calibration information. The coordinates (X, X) of the target point in the coordinate system {T} of the serial robot end effector can be obtained. T ,Y T Z T Here, the relationship between the first coordinate position and the actual position coordinates is expressed as:

[0055]

[0056] in, Let represent the rotation transformation matrix of the target coordinate system {A} relative to the coordinate system of the end effector of the serial robot. It is a translation vector; Indicates the actual position coordinates; Indicates the first coordinate position.

[0057] Finally, the pose P1 = (X1,Y1,Z1,α1,β1,γ1) of the parallel robot's gripping component in the coordinate system of the serial robot's end effector was solved. T Where X1 represents the X-axis coordinate of the first coordinate position; Y1 represents the Y-axis coordinate of the first coordinate position; Z1 represents the Z-axis coordinate of the first coordinate position; α1 represents the X-axis rotation angle of the first coordinate position; β1 represents the Y-axis rotation angle of the first coordinate position; and γ1 represents the Z-axis rotation angle of the first coordinate position.

[0058] For example, the transformation relationship between the coordinate system {E} of the serial robot gripping component and the coordinate system of the serial robot end effector. The pose of the component in the coordinate system of the end effector of the serial robot is P2=(X2,Y2,Z2,α2,β2,γ2). T Where X2 represents the X-axis coordinate of the second coordinate position; Y2 represents the Y-axis coordinate of the second coordinate position; Z2 represents the Z-axis coordinate of the second coordinate position; α2 represents the X-axis rotation angle of the second coordinate position; β2 represents the Y-axis rotation angle of the second coordinate position; and γ2 represents the Z-axis rotation angle of the second coordinate position.

[0059] S103, the parallel robot and the serial robot move to the first optimal assembly position and the second optimal assembly position according to their relative poses;

[0060] S104, the parallel robot adjusts the first optimal assembly position through the torque sensing module to complete the intelligent assembly of the two robots.

[0061] Specifically, in step S104, the force transmission model is set on the server, and the torque sensing module includes: a sensor module and a second data processing module; the sensor module is set at the translational joint of the parallel robot; and the second data processing module is set on the server.

[0062] Here, the force transmission model is expressed as:

[0063]

[0064]

[0065] in,P F ext This indicates the force acting on the end effector of a parallel robot; P J kin F represents the Jacobian matrix of a parallel robot; q =(f1,f2,f3,f4,f5,f6) T This indicates the force measured by the sensor module; P F G Represents gravity; Represents the rotation matrix from the coordinate system of the end effector of the parallel robot to the base coordinate system of the parallel robot; p x sp Indicates the center of gravity position of the end effector of the parallel robot; F q0 This indicates the zero-position drift caused by platform deformation; This indicates the zero-position drift caused by changes in the position of the end effector; B g represents the gravitational acceleration in the parallel robot's coordinate system. B g = (0, 0, 9.81) T ;m p This represents the mass of the parallel robot's motion platform. In one possible implementation, the force transmission model is set up on a server.

[0066] Specifically, in step S104, the parallel robot adjusts the first optimal assembly position through the torque sensing module to complete the intelligent assembly of the two robots, including the following steps S1041 to S1043.

[0067] S1041, multiple measurement values ​​are obtained by using multiple sensor modules in the torque sensing module;

[0068] S1042, the first force vector is obtained by calculating multiple measured values ​​through a force transmission model;

[0069] S1043, control the movement of the parallel robot according to the first force vector, adjust the first optimal assembly position, repeat steps S1041 and S1042 during the movement of the parallel robot, ensure that the first force vector does not exceed the preset value, until the intelligent assembly of the two robots is completed.

[0070] For example, sensor modules are installed on each translational joint of the parallel robot, which, together with the second data processing module, form a force / torque sensing system to sense the external force exerted on the component to be assembled by the end of the parallel robot and to feed the data back to the second data processing module.

[0071] During assembly, a force / torque sensing system monitors the interaction forces / torques between the components to be assembled in real time. Based on the acquired interaction forces / torques, the movement of the parallel robot is adjusted to ensure that the interaction forces / torques between the components do not exceed preset values. The movement of the parallel robot is further adjusted according to these interaction forces to ensure a smooth assembly process until assembly is complete. The parallel robot and the serial robot then move to the initial pose for the next work stage.

[0072] In a specific embodiment provided by the present invention, such as Figure 3 As shown, the sensor module consists of six one-dimensional tension / compression sensors, which are respectively installed on the six translational joints of the parallel robot; the data processing module contains the transmission model of the force on the end effector and the joint driving force of the parallel robot.

[0073] In a specific usage embodiment provided by the present invention, such as Figure 4 As shown, the first stage of the assembly process:

[0074] Step 1: The parallel robot clamps the large first component to be assembled and reaches the preset assembly pose through position control; the serial robot clamps the small second component to be assembled and reaches the first preset assembly pose and the second preset assembly pose respectively through position control.

[0075] Step 2: Obtain the relative pose relationships between the components to be assembled through the visual perception module;

[0076] Step 3: Obtain the pose error data set from Step 2, process it to obtain the compensation data set, and use it to control the serial robot to move to the second optimal assembly position.

[0077] Step 4: Control the movement of the serial robot to begin assembly.

[0078] Second stage of assembly process:

[0079] Step 5: During the assembly process, the interaction force / torque between the first and second components to be assembled is monitored in real time by the force / torque sensing module. Based on the acquired interaction force / torque, the motion of the parallel robot is adjusted according to a certain strategy to ensure that the interaction force / torque between the assembled components does not exceed the preset value.

[0080] Repeat step 5 until assembly is complete.

[0081] Third stage of assembly process:

[0082] Step 6: Assembly complete. The parallel robot moves to the initial pose of the next working stage, and the serial robot moves to the initial pose of the next working stage.

[0083] The various embodiments described in this specification are presented in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. All or part of this invention can be used in numerous general-purpose or special-purpose computer system environments or configurations. Examples include: personal computers, server computers, handheld or portable devices, tablet devices, mobile communication terminals, multiprocessor systems, microprocessor-based systems, programmable electronic devices, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices, etc.

[0084] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

Claims

1. An intelligent assembly method based on series-parallel dual robot cooperation, characterized in that, The parallel robot clamps a first component to be assembled, moves the first component to be assembled to a first preset assembly pose, and the end effector of the serial robot clamps a second component to be assembled, moves the second component to be assembled to a second preset assembly pose. The relative pose between the first component to be assembled and the second component to be assembled is obtained through a visual perception module. The visual perception module comprises a binocular camera, a target and a first data processing module; the binocular camera is arranged on the serial robot; the target is arranged on the first component to be assembled; and the first data processing module is arranged on a server; wherein the relative pose between the first component to be assembled and the second component to be assembled is obtained through the visual perception module, which comprises obtaining a first coordinate position of the target in a camera coordinate system of the parallel robot through the target; obtaining a second coordinate position of the target in a target coordinate system of the binocular camera by using the binocular camera and the first coordinate position; determining a transformation relationship between the camera coordinate system and the target coordinate system by using calibration information of the binocular camera, the first coordinate position and the second coordinate position; and obtaining an actual position coordinate of the target in an end effector coordinate system of the serial robot as the relative pose between the first component to be assembled and the second component to be assembled according to the transformation relationship; The parallel robot and the serial robot move to a first optimal assembly position and a second optimal assembly position according to the relative pose; the parallel robot adjusts the first optimal assembly position through a torque perception module to complete the dual-robot intelligent assembly, which comprises obtaining a plurality of measurement values by using a plurality of sensor modules in the torque perception module; calculating the plurality of measurement values through a force transmission model to obtain a first force vector; and adjusting the first optimal assembly position by controlling the motion of the parallel robot according to the first force vector to ensure that the first force vector does not exceed a preset value until the dual-robot intelligent assembly is completed. The parallel robot adjusts the first optimal assembly position through the torque perception module to complete the dual-robot intelligent assembly. The torque perception module comprises a sensor module and a second data processing module.

2. The intelligent assembly method based on series-parallel dual robot cooperation according to claim 1, characterized in that, The sensor module is arranged at a prismatic joint of the parallel robot. The second data processing module is arranged on a server. The relationship between the first coordinate position and the actual position coordinate is represented as:

3. The intelligent assembly method based on series-parallel dual robot cooperation according to claim 1, characterized in that, The force transmission model is represented as: ； wherein, denotes a rotation transformation matrix of a target coordinate system A} with respect to an end effector coordinate system of a serial robot, is a translation vector; denotes an actual position coordinate; denotes a first coordinate position.

4. The intelligent assembly method based on series-parallel dual robot cooperation according to claim 1, characterized in that, The force transmission model is arranged on a server. ； ； wherein, represents the force experienced by the parallel robot end-effector; represents the parallel robot Jacobian matrix; represents the force measured by the sensor module; represents the gravity; represents the rotation matrix from the parallel robot end-effector coordinate frame to the parallel robot base coordinate frame; represents the parallel robot end-effector center of gravity position; represents the zero position drift due to the platform deformation; represents the zero position drift due to the end-effector position change; represents the gravity acceleration in the parallel robot coordinate frame, taken as ; represents the mass of the parallel robot moving platform.

5. The intelligent assembly method based on series-parallel dual robot cooperation according to claim 1, characterized in that, The sensor module is a one-dimensional tension / compression force sensor.

6. The intelligent assembly method based on series-parallel dual robot cooperation according to claim 1, characterized in that, ​

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