Intelligent assembling method based on cooperation of series-parallel double robots

Abstract

The invention discloses an intelligent assembling method based on cooperation of series-parallel double robots, and solves the problems that in the prior art, flexible control is difficult to realize in the assembling process of aerospace equipment, and an assembling system does not have high automation and high universality. The method comprises the steps that an end effector of a parallel robot clamps a first to-be-assembled component, the first to-be-assembled component is moved to a first preset assembly pose, an end effector of a series robot clamps a second to-be-assembled component, and the second to-be-assembled component is moved to a second preset assembly pose; obtaining a relative pose through a visual perception module; the parallel robot and the series robot move to the optimal assembly position according to the relative poses; the parallel robot adjusts a first optimal assembly position through a torque sensing module to complete double-robot intelligent assembly; the automatic degree, the working efficiency and the flexibility of large-scale component assembly are effectively improved in an unstructured dynamic environment by utilizing a visual and haptic composite auxiliary mode.

Description

Technical Field

[0001] The present invention relates to the technical field of automated assembly, and in particular to an intelligent assembly method based on serial-parallel dual-robot collaboration. Background Art

[0002] The aerospace industry is an important symbol of a country's economy, national defense and industrialization level. Assembly is the final stage and key process link of aerospace equipment manufacturing. The work in this stage accounts for about 50% and 30% of the total time and total cost of the entire manufacturing cycle of the equipment, respectively. Traditional large-scale component docking and assembly usually adopts the manual operation method of "visual observation, shouting and manual pushing", which mainly relies on a large number of workers and a small number of tooling equipment.

[0003] The main problems of the existing technology are that it requires the collaborative operation of multiple people, has low assembly efficiency, high labor intensity, poor assembly quality consistency, and flexibility cannot be guaranteed during the assembly process. Summary of the invention

[0004] The present invention provides an intelligent assembly method based on serial-parallel dual robot collaboration, which solves the problems in the prior art that it is difficult to achieve flexible control in the assembly process of aerospace equipment and the assembly system does not have high automation and high universality. It uses a composite assistance method of vision and force to effectively improve the degree of automation, work efficiency and flexibility of large-scale component assembly in an unstructured dynamic environment.

[0005] The present invention provides an intelligent assembly method based on serial-parallel dual-robot collaboration, 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 posture, and 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 posture;

[0007] Acquire the relative position between the first component to be assembled and the second component to be assembled by a visual perception module;

[0008] The parallel robot and the serial robot move to a first optimal assembly position and a second optimal assembly position according to the relative posture;

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

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

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

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

[0013] The first data processing module is arranged on a server.

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

[0015] The sensor module is arranged at the translation joint of the parallel robot;

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

[0017] In a possible implementation, the acquiring the relative position between the first component to be assembled and the second component to be assembled by using a visual perception module includes:

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

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

[0020] Determine the transformation relationship between the camera coordinate system and the target coordinate system using the calibration information of the binocular camera, the first coordinate position, and the second coordinate position;

[0021] Obtaining the actual position coordinates of the target in the end effector coordinate system of the serial robot according to the transformation relationship;

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

[0023] In a possible implementation manner, the relationship between the first coordinate position and the actual position coordinate is expressed as:

[0024]

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

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

[0027] Using multiple sensor modules in the torque sensing module to obtain multiple measurement values;

[0028] Calculating the plurality of measured values ​​by using a force transfer model to obtain a first force vector;

[0029] The movement of the parallel robot is controlled according to 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 a possible implementation, the force transfer model is expressed as:

[0031]

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

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

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

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

[0036] The present invention optimizes and provides an intelligent assembly method based on serial-parallel dual robot collaboration from the aspects of high flexibility, high efficiency and safety, and utilizes a composite assistance method of vision and force to effectively improve the degree of automation, work efficiency and flexibility of large-scale component assembly in an unstructured dynamic environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A flowchart of the steps of an intelligent assembly method based on serial-parallel dual robot collaboration provided by an embodiment of the present invention;

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

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

[0040] Figure 4 An assembly flow chart provided for an embodiment of the present invention. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] The present invention provides an intelligent assembly method based on serial-parallel dual robot collaboration, 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 a first preset assembly posture, and 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 posture.

[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 the components to reach the first preset assembly posture and the second preset assembly posture.

[0045] S102: Acquire the relative position between the first component to be assembled and the second component to be assembled through a 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 set on the serial robot; the target is set on the first component to be assembled; and the first data processing module is set on the server.

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

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

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

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

[0051] S1024, obtaining the actual position coordinates of the target in the end effector coordinate system of the serial robot according to the transformation relationship;

[0052] S1025, taking the actual position coordinates as the relative posture.

[0053] Exemplarily, a binocular camera is installed on the serial robot, which is combined with the first data processing module and a target placed on the first component to be assembled clamped by the parallel robot to form a visual perception system to obtain the relative position relationship between the two components to be assembled and feed the data back to the first data processing module.

[0054] like Figure 2 The visual perception system shown is composed of a binocular camera mounted on a serial robot, a first data processing module, and a target placed on the end effector of a parallel robot for clamping a first component to be assembled. The position (X A ,Y A ,Z A ), obtain the position of the target point in the camera coordinate system through visual measurement, and then obtain the transformation relationship between the camera coordinate system and the serial robot end effector coordinate system through calibration information The coordinates of the target point in the coordinate system {T} of the serial robot end effector can be obtained (X T ,Y T ,Z T ). Here, the relationship between the first coordinate position and the actual position coordinate is expressed as:

[0055]

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

[0057] Finally, the position of the parallel robot gripping component in the serial robot end effector coordinate system is solved as P1 = (X1, Y1, Z1, α1, β1, γ1) 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; γ1 represents the Z-axis rotation angle of the first coordinate position.

[0058] Exemplarily, the transformation relationship between the coordinate system {E} of the serial robot gripping component and the coordinate system of the serial robot end effector is The position of the component in the coordinate system of the serial robot end effector 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; γ2 represents the Z-axis rotation angle of the second coordinate position.

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

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

[0061] Specifically, in step S104, the force transfer 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 transfer model is expressed as:

[0063]

[0064]

[0065] in,P F ext It represents the force on the end effector of the parallel robot; P J kin represents the Jacobian matrix of the parallel robot; F q =(f1,f2,f3,f4,f5,f6) T Represents the force measured by the sensor module; P F G Indicates gravity; Represents the rotation matrix from the parallel robot end effector coordinate system to the parallel robot base coordinate system; p x sp Indicates the center of gravity of the parallel robot end effector; F q0 Indicates the zero drift caused by platform deformation; Indicates the zero position drift caused by the change in the end effector position; B g represents the gravitational acceleration in the parallel robot coordinate system. B g=(0,0,9.81) T ;m p Indicates the mass of the parallel robot dynamic platform. In a possible implementation, the force transmission model is set on the server.

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

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

[0068] S1042, calculating the multiple measurement values ​​through a force transfer model to obtain a first force vector;

[0069] S1043, controlling the movement of the parallel robot according to the first force vector, adjusting the first optimal assembly position, and repeating steps S1041 and S1042 during the movement of the parallel robot to ensure that the first force vector does not exceed a preset value until the dual-robot intelligent assembly is completed.

[0070] Exemplarily, a sensor module is installed on each translational joint of the parallel robot, and combined with the second data processing module, a force / torque sensing system is formed to sense the external force acting on the assembly component clamped at the end of the parallel robot, and feed the data back to the second data processing module.

[0071] During the assembly process, the force / torque sensing system monitors the interaction force / torque between the components to be assembled in real time, and adjusts the motion of the parallel robot according to the acquired interaction force / torque to ensure that the interaction force / torque between the assembled components does not exceed the preset value. The motion of the parallel robot is adjusted according to the interaction force to make the assembly process smooth until the assembly is completed. The parallel robot and the serial robot move to the initial position of the next working stage.

[0072] In a specific embodiment provided by the present invention, Figure 3 As shown, the sensor module consists of 6 one-dimensional pull / pressure sensors, which are respectively installed on the 6 translational joints of the parallel robot; the data processing module includes a transmission model of the end force of the parallel robot and the joint driving force.

[0073] In a specific use embodiment provided by the present invention, 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 posture through position control; the serial robot clamps the small second component to be assembled and reaches the first preset assembly posture and the second preset assembly posture respectively through position control;

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

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

[0077] Step 4: Control the serial robot to start assembly.

[0078] Second stage of assembly process:

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

[0080] Repeat step 5 until the assembly is complete.

[0081] The third stage of the assembly process:

[0082] Step 6: After assembly is completed, the parallel robot moves to the initial position of the next working stage, and the serial robot moves to the initial position of the next working stage.

[0083] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. All or part of the present invention can be used in many general or special computer system environments or configurations. For example: personal computers, server computers, handheld devices or portable devices, tablet devices, mobile communication terminals, multi-processor systems, microprocessor-based systems, programmable electronic devices, network PCs, minicomputers, mainframe computers, 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, rather than to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the present invention.

Claims

1. An intelligent assembly method based on serial-parallel dual robot collaboration, characterized in that: include: 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 posture, and 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 posture; Acquire the relative position between the first component to be assembled and the second component to be assembled by a visual perception module; The parallel robot and the serial robot move to a first optimal assembly position and a second optimal assembly position according to the relative posture; The parallel robot adjusts the first optimal assembly position through the torque sensing module to complete the dual-robot intelligent assembly.

2. The intelligent assembly method based on serial-parallel dual robot collaboration according to claim 1 is characterized in that: The visual perception module includes: 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; The first data processing module is arranged on a server.

3. The intelligent assembly method based on serial-parallel dual robot collaboration according to claim 1 is characterized in that: The torque sensing module includes: a sensor module and a second data processing module; The sensor module is arranged at the translation joint of the parallel robot; The second data processing module is arranged on the server.

4. The intelligent assembly method based on serial-parallel dual robot collaboration according to claim 2 is characterized in that: The step of obtaining the relative position between the first component to be assembled and the second component to be assembled by using a visual perception module includes: Obtaining, by means of the target, a first coordinate position of the target in a camera coordinate system where the parallel robot is located; Using the binocular camera and the first coordinate position, obtaining a second coordinate position of the target in a target coordinate system where the binocular camera is located; Determine the transformation relationship between the camera coordinate system and the target coordinate system using the calibration information of the binocular camera, the first coordinate position, and the second coordinate position; The actual position coordinates of the target in the end effector coordinate system of the serial robot are obtained according to the transformation relationship as the relative position and posture between the first component to be assembled and the second component to be assembled.

5. The intelligent assembly method based on serial-parallel dual robot collaboration according to claim 4 is characterized in that: The relationship between the first coordinate position and the actual position coordinate is expressed as: in, represents the rotation transformation matrix of the target coordinate system {A} relative to the end effector coordinate system of the serial robot, is the translation vector; Indicates the actual position coordinates; Indicates the first coordinate position.

6. The intelligent assembly method based on serial-parallel dual robot collaboration according to claim 3 is characterized in that: The parallel robot adjusts the first optimal assembly position through the torque sensing module to complete dual-robot intelligent assembly, including: Using multiple sensor modules in the torque sensing module to obtain multiple measurement values; Calculating the multiple measurement values ​​through a force transfer model to obtain a first force vector; The movement of the parallel robot is controlled according to 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.

7. The intelligent assembly method based on serial-parallel dual robot collaboration according to claim 6 is characterized in that: The force transfer model is expressed as: in, P F ext It represents the force on the end effector of the parallel robot; P J kin represents the Jacobian matrix of the parallel robot; F q =(f1,f2,f3,f4,f5,f6) T Represents the force measured by the sensor module; P F G Indicates gravity; Represents the rotation matrix from the parallel robot end effector coordinate system to the parallel robot base coordinate system; p x sp Indicates the center of gravity of the parallel robot end effector; F q0 Indicates the zero drift caused by platform deformation; Indicates the zero position drift caused by the change in the end effector position; B g represents the gravitational acceleration in the parallel robot coordinate system. B g=(0,0,9.81) T ;m p Represents the mass of the parallel robot's dynamic platform.

8. The intelligent assembly method based on serial-parallel dual robot collaboration according to claim 6 is characterized in that: The force transfer model is set on the server.

9. The intelligent assembly method based on serial-parallel dual robot collaboration according to claim 6, characterized in that: The sensor module is a one-dimensional pull / pressure sensor.

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