High-precision self-adaptive assembling device and method for shaft hole

Abstract

The invention relates to a high-precision self-adaptive assembling device and method for shaft holes. The method comprises the steps that an AGV carries a six-axis robot to navigate to a designated assembling station; the shaft is placed in a shaft positioning tool on the AGV; the shaft sleeve is placed in the shaft sleeve positioning tool and clamped; a six-axis robot action instruction is sent, the six-axis robot moves to the area where the shaft and the shaft sleeve are located according to the teaching track to take a picture, shaft and shaft sleeve end face angle alignment is conducted, the size of the shaft is recognized, the position coordinate offset of the shaft and the shaft sleeve is detected, and the motion track from the shaft to the shaft sleeve is corrected; and the six-axis robot selects a matched clamping jaw according to the identified shaft size, moves to the position of the shaft to grab the shaft, conveys the shaft to the position right opposite to the inlet of the shaft sleeve according to the corrected track, and combines force data fed back by the force data control sensor module to accurately insert the shaft into the shaft sleeve. Intelligent and self-adaptive high-precision part assembly is realized, the fit clearance is superior to + / -0.05 mm, the assembly accuracy is ensured, the assembly efficiency is improved, and obvious collision and surface damage between workpieces are avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of automatic assembly, and relates to a high-precision self-adaptive assembly device and method for a shaft hole. Background Art

[0002] In the production workshop, the traditional hole-shaft assembly task is completed manually. The hole-shaft assembly is divided into various models, and it should be ensured that there is no obvious bump and surface damage between the workpieces. During the assembly process, the assembly workers must always concentrate, which consumes a lot of manpower and the assembly efficiency is not high. The assembly link is an important link in the product manufacturing process, which affects the quality and production cost of the product. Therefore, it is necessary to design a high-precision adaptive assembly device for the shaft hole to improve the assembly efficiency and assembly quality. Summary of the invention

[0003] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art, to propose a high-precision adaptive assembly device and method for shaft holes, to realize intelligent, adaptive high-precision parts assembly, with a matching clearance better than ±0.05mm, to ensure accurate assembly, to improve assembly efficiency, and to eliminate obvious bumps and surface damage between workpieces.

[0004] The technical solution of the present invention is: a high-precision adaptive assembly device for shaft holes, including an AGV, a six-axis robot, a force control sensor module, a tool end quick-change gripping assembly and a PLC controller;

[0005] The AGV is used to navigate to a workstation where the shaft and the shaft sleeve need to be matched after receiving a scheduling instruction, the shaft sleeve to be assembled is placed on the workstation, and the shaft to be assembled is placed on the AGV;

[0006] The six-axis robot is installed on the AGV, and performs actions according to the teaching trajectory based on the pre-stored position coordinates of the shaft and sleeve, and takes photos when it reaches the area where the shaft and sleeve are located. It corrects the teaching trajectory from the shaft to the sleeve according to the position coordinate offset of the shaft and sleeve sent by the PLC controller, and executes the corrected trajectory to complete the assembly docking task.

[0007] The force control sensor module is installed at the end of the six-axis robot to control and adjust the force during the insertion of the shaft into the sleeve;

[0008] The tool-end quick-change gripping assembly is placed on the AGV, including a vision assembly and multiple sets of grippers. When the six-axis robot reaches the area where the shaft and sleeve are located, the vision assembly is automatically installed at the end of the six-axis robot to obtain the precise position coordinates of the shaft and sleeve and identify the size of the shaft. The gripper that matches the shaft size is selected and automatically installed at the end of the six-axis robot.

[0009] The PLC controller is used to send motion instructions to the six-axis robot; receive the precise position coordinates of the shaft and sleeve sent by the visual component, subtract them from the pre-stored position coordinates of the shaft and sleeve, and send the position coordinate offset of the shaft and sleeve to the six-axis robot.

[0010] Furthermore, the force control sensor module adopts a six-dimensional force sensor.

[0011] Furthermore, the gripper claws of the quick-change gripping assembly at the tool end are provided with a floating head and an electrical docking module, which are connected to a force control sensor module. During the assembly process, the control sensor module feeds back the friction resistance magnitude and direction data from the sleeve to the force control module of the robot control system in real time, which is used for the six-axis robot to calculate and adjust the posture in real time, and assemble the shaft into the sleeve with the cooperation of the floating head.

[0012] Furthermore, the visual component uses a laser displacement sensor + CCD camera. The laser displacement sensor is used to align the angles of the shaft and sleeve end faces to ensure that the CCD camera shoots the vertical shaft and sleeve end faces; the CCD camera is used to obtain the precise position coordinates of the shaft and sleeve and send them to the PLC controller, and identify the size of the shaft.

[0013] Furthermore, the shaft hole high-precision adaptive assembly device also includes a shaft sleeve positioning tool for fixing the shaft sleeve; before the formal assembly, the shaft sleeve positioning tool is mounted on the edge of the AGV and close to the assembly station, and is used to implement the motion training of the six-axis robot from the shaft to the shaft sleeve on the AGV, forming a teaching trajectory from the shaft to the shaft sleeve; during the formal assembly, the shaft sleeve positioning tool is placed at the assembly station to clamp the shaft sleeve.

[0014] Furthermore, the shaft sleeve positioning tool adopts a flexible clamp to realize the positioning and clamping of the shaft sleeve, and the clamp bottom plate is adjustable left and right.

[0015] Furthermore, the AGV is also provided with an axis positioning tool for fixing the axis.

[0016] A high-precision self-adaptive assembly method for a shaft hole comprises the following steps:

[0017] The dispatching system sends AGV dispatching instructions, and the AGV carries the six-axis robot and navigates to the designated assembly station;

[0018] Place the shaft into the shaft positioning fixture on the AGV;

[0019] Place the sleeve into the sleeve positioning tool at the designated assembly station and clamp it;

[0020] Send the six-axis robot action command, and the six-axis robot moves to the area where the shaft and sleeve are located according to the teaching trajectory to take pictures, align the end face angles of the shaft and sleeve, identify the size of the shaft, detect the position coordinate offset of the shaft and sleeve, and correct the movement trajectory from the shaft to the sleeve;

[0021] The six-axis robot selects the appropriate gripper according to the axis size identified by the visual component;

[0022] The six-axis robot moves to the position of the shaft to grab it, and delivers the shaft to the position opposite the entrance of the sleeve according to the corrected motion trajectory. Combined with the real-time feedback of the force data from the force control sensor module, the shaft is accurately inserted into the sleeve.

[0023] Furthermore, the navigation method of AGV is as follows:

[0024] SLAM+PGV composite navigation is adopted, and the dispatching system sends navigation task information to the navigation controller of AGV; the navigation controller first uses SLAM as a navigation sensor, and the navigation controller and the dispatching system continuously feedback the speed and position information to control the AGV to drive along the set route until the positioning feedback of the PGV sensor through the transparent transmission protocol is consistent with the navigation target point. At this time, PGV is switched to as the navigation sensor, and AGV performs closed-loop control according to the PGV feedback information until the positioning position information meets the task requirements, and then transmits the navigation task completion information to the dispatching system, and this navigation task ends.

[0025] The beneficial effects of the present invention compared with the prior art are:

[0026] (1) The present invention proposes a hole-shaft adaptive assembly device that integrates AGV, machine vision and robot end force control. Based on the AGV automatic navigation technology, the robot can be automatically driven to the assembly site. The robot guidance method based on visual positioning can enable the robot to quickly find holes and align; based on the robot end force control method, the robot can achieve smooth insertion. The adaptive assembly technology can effectively improve assembly efficiency and assembly quality.

[0027] (2) The embodiment of the present invention combines the robot's end force control and floating head. When the shaft is inserted into the sleeve, the shaft will be subject to the friction of the sleeve, making it difficult to insert smoothly. The six-dimensional force sensor measures the magnitude and direction of the friction resistance from the sleeve, and feeds back the resistance value and direction to the robot's force control module. The robot will automatically adjust the insertion direction, and with the cooperation of the floating head that can move in all directions, the shaft will be inserted into the sleeve with a certain angle deviation, while ensuring that the insertion action is precise and does not damage the material.

[0028] (3) When the AGV reaches the workstation, it uses a QR code to perform precise positioning correction with an accuracy of ±2.5 mm.

[0029] (4) The present invention uses a CCD camera to identify the size of the shaft and the sleeve, and simultaneously detects the position coordinate offset of the shaft and the sleeve, and provides it to the six-axis robot for point coordinate correction during operation. Based on the field of view of 50X30mm, the recognition accuracy reaches ±0.01mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of a high-precision adaptive assembly device for a shaft hole according to an embodiment of the present invention;

[0031] In the picture: 1-AGV, 2-six-axis robot, 3-force control sensor module, 4-sleeve positioning tooling, 5-tool end quick-change gripping assembly. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0033] Example 1

[0034] like Figure 1 As shown, a high-precision adaptive assembly device for shaft holes proposed by the present invention includes an AGV 1, a six-axis robot 2, a force control sensor module 3, a tool end quick-change gripping assembly 5 and a PLC controller;

[0035] AGV1 is used to navigate to a workstation where a shaft and a shaft sleeve need to be matched after receiving a scheduling instruction, where a shaft sleeve to be assembled is located at the workstation, and a shaft to be assembled is placed on the AGV1;

[0036] The six-axis robot 2 is installed on AGV 1, and performs actions according to the teaching trajectory based on the pre-stored position coordinates of the shaft and sleeve, and arrives at the area where the shaft and sleeve are located to take pictures; the teaching trajectory from the shaft to the sleeve is corrected according to the position coordinate offset of the shaft and sleeve sent by the PLC controller, and the corrected trajectory is executed to complete the assembly docking task;

[0037] The force control sensor module 3 is installed at the end of the six-axis robot 2 and is used to control and adjust the force during the process of the shaft inserting into the sleeve;

[0038] The tool-end quick-change grasping assembly 5 is placed on the AGV 1, including a vision assembly and multiple sets of grippers; when the six-axis robot 2 reaches the area where the shaft and the sleeve are located, the vision assembly is automatically installed at the end of the six-axis robot 2 to obtain the precise position coordinates of the shaft and the sleeve and identify the size of the shaft; the gripper that matches the shaft size is selected and automatically installed at the end of the six-axis robot 2.

[0039] The PLC controller is used to send action instructions to the six-axis robot 2; receive the precise position coordinates of the shaft and sleeve sent by the visual component, subtract them from the pre-stored position coordinates of the shaft and sleeve, and send the position coordinate offset of the shaft and sleeve to the six-axis robot 2.

[0040] In this embodiment, the force control sensor module 3 adopts a six-dimensional force sensor. With the support of the force control package integrating the six-dimensional force sensor and the six-axis robot 2, the six-axis robot 2 can accurately control the insertion resistance within 5.5N and insert the shaft into the sleeve without damage.

[0041] In this embodiment, the clamping claws of the tool end quick-change grasping assembly 5 are provided with a floating head and an electrical docking module, and the electrical docking module is connected to the force control sensor module 3. During the assembly process, the six-dimensional force sensor feeds back the friction resistance size and direction data from the sleeve to the force control module of the robot control system in real time. The six-axis robot 2 adjusts the posture through the force control package calculation, and assembles the shaft into the sleeve with the cooperation of the floating head.

[0042] In this embodiment, the visual component uses a laser displacement sensor + CCD camera. The laser displacement sensor is used to align the angles of the shaft and sleeve end faces to ensure that the CCD camera shoots the vertical axis and sleeve end faces; the CCD camera is used to obtain the precise position coordinates of the shaft and sleeve and send them to the PLC controller, and identify the size of the shaft.

[0043] The shaft hole high-precision adaptive assembly device also includes a shaft sleeve positioning tool 4, which is used to fix the shaft sleeve; before the formal assembly, the shaft sleeve positioning tool 4 is mounted on the edge of the AGV1 and close to the assembly station, and is used to implement the movement training of the six-axis robot 2 from the shaft to the shaft sleeve on the AGV1, forming a teaching trajectory from the shaft to the shaft sleeve; during the formal assembly, the shaft sleeve positioning tool 4 is placed at the assembly station to clamp the shaft sleeve.

[0044] In this embodiment, the AGV 1 is also provided with an axis positioning tool for fixing the axis.

[0045] The shaft sleeve positioning tool 4 adopts a flexible clamp to realize the positioning and clamping of the shaft sleeve, and the clamp bottom plate is adjustable left and right to meet the needs of multiple size changes of the shaft sleeve.

[0046] Based on a shaft hole high-precision adaptive assembly device of the present invention, a shaft hole high-precision adaptive assembly method is proposed, comprising the following steps:

[0047] The dispatching system sends AGV dispatching instructions, and AGV1 carries the six-axis robot 2 and navigates to the designated assembly station;

[0048] Place the axis into the axis positioning fixture on AGV1;

[0049] Place the sleeve into the sleeve positioning tool 4 at the designated assembly station and clamp it;

[0050] Send the action command of the six-axis robot 2, and the six-axis robot 2 moves to the area where the shaft and the sleeve are located according to the teaching trajectory to take pictures, align the end face angles of the shaft and the sleeve, identify the size of the shaft, and detect the position coordinate offset of the shaft and the sleeve at the same time, and correct the movement trajectory from the shaft to the sleeve;

[0051] The six-axis robot 2 selects a suitable gripper according to the axis size identified by the visual component;

[0052] The six-axis robot 2 moves to the position of the shaft to grab it, and delivers the shaft to the position opposite to the entrance of the sleeve according to the corrected motion trajectory. Combined with the force data fed back in real time by the force control sensor module 3, the shaft is accurately inserted into the sleeve.

[0053] In this embodiment, the navigation method of AGV1 is as follows:

[0054] Using SLAM+PGV composite navigation, the dispatching system sends navigation task information to the navigation controller of AGV1; the navigation controller first uses SLAM as a navigation sensor, and the navigation controller and the dispatching system continuously feedback information such as speed and position, and control the AGV to drive along the set route until the positioning feedback of the PGV sensor through the transparent transmission protocol is consistent with the navigation target point, at which time it switches to PGV as the navigation sensor. At this time, AGV1 performs closed-loop control based on the PGV feedback information until the positioning position information meets the task requirements, and then transmits the navigation task completion information to the dispatching system, and this navigation task ends.

[0055] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

[0056] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A high-precision self-adaptive assembly device for a shaft hole, characterized in that: Includes AGV, six-axis robot, force control sensor module, tool-end quick-change gripper assembly and PLC controller; The AGV is used to navigate to a workstation where the shaft and the shaft sleeve need to be matched after receiving a scheduling instruction, the shaft sleeve to be assembled is placed on the workstation, and the shaft to be assembled is placed on the AGV; The six-axis robot is installed on the AGV, and performs actions according to the teaching trajectory based on the pre-stored position coordinates of the shaft and sleeve, and takes photos when it reaches the area where the shaft and sleeve are located. It corrects the teaching trajectory from the shaft to the sleeve according to the position coordinate offset of the shaft and sleeve sent by the PLC controller, and executes the corrected trajectory to complete the assembly docking task. The force control sensor module is installed at the end of the six-axis robot to control and adjust the force during the insertion of the shaft into the sleeve; The tool-end quick-change gripping assembly is placed on the AGV, including a vision assembly and multiple sets of grippers. When the six-axis robot reaches the area where the shaft and sleeve are located, the vision assembly is automatically installed at the end of the six-axis robot to obtain the precise position coordinates of the shaft and sleeve and identify the size of the shaft. The gripper that matches the shaft size is selected and automatically installed at the end of the six-axis robot. The PLC controller is used to send motion instructions to the six-axis robot; receive the precise position coordinates of the shaft and sleeve sent by the visual component, subtract them from the pre-stored position coordinates of the shaft and sleeve, and send the position coordinate offset of the shaft and sleeve to the six-axis robot.

2. A high-precision self-adaptive assembly device for shaft holes according to claim 1, characterized in that: The force control sensor module uses a six-dimensional force sensor.

3. The high-precision self-adaptive assembly device for shaft holes according to claim 1, characterized in that: The gripper claws of the quick-change gripping assembly at the tool end are provided with a floating head and an electrical docking module. The electrical docking module is connected to the force control sensor module. During the assembly process, the control sensor module feeds back the friction resistance size and direction data from the sleeve to the force control module of the robot control system in real time, which is used for the six-axis robot to calculate and adjust the posture in real time, and assemble the shaft into the sleeve with the cooperation of the floating head.

4. The high-precision self-adaptive assembly device for shaft holes according to claim 1, characterized in that: The visual component uses a laser displacement sensor + CCD camera. The laser displacement sensor is used to align the angles of the shaft and sleeve end faces to ensure that the CCD camera shoots the vertical shaft and sleeve end faces; the CCD camera is used to obtain the precise position coordinates of the shaft and sleeve and send them to the PLC controller, and identify the size of the shaft.

5. The high-precision self-adaptive assembly device for shaft holes according to claim 1, characterized in that: The shaft-hole high-precision adaptive assembly device also includes a shaft sleeve positioning tool for fixing the shaft sleeve; before formal assembly, the shaft sleeve positioning tool is mounted on the edge of the AGV and close to the assembly station, and is used to implement the motion training of the six-axis robot from the shaft to the shaft sleeve on the AGV, forming a teaching trajectory from the shaft to the shaft sleeve; during formal assembly, the shaft sleeve positioning tool is placed at the assembly station to clamp the shaft sleeve.

6. The high-precision self-adaptive assembly device for shaft holes according to claim 5, characterized in that: The shaft sleeve positioning tool adopts a flexible clamp to realize the positioning and clamping of the shaft sleeve, and the clamp bottom plate is adjustable left and right.

7. The high-precision self-adaptive assembly device for shaft holes according to claim 1, characterized in that: The AGV is also equipped with an axis positioning tool for fixing the axis.

8. A high-precision adaptive assembly method for shaft holes based on the device according to any one of claims 1 to 7, characterized in that: The following steps are involved: The dispatching system sends AGV dispatching instructions, and the AGV carries the six-axis robot and navigates to the designated assembly station; Place the shaft into the shaft positioning fixture on the AGV; Place the sleeve into the sleeve positioning tool at the designated assembly station and clamp it; Send the six-axis robot action command, and the six-axis robot moves to the area where the shaft and sleeve are located according to the teaching trajectory to take pictures, align the end face angles of the shaft and sleeve, identify the size of the shaft, detect the position coordinate offset of the shaft and sleeve, and correct the movement trajectory from the shaft to the sleeve; The six-axis robot selects the appropriate gripper according to the axis size identified by the visual component; The six-axis robot moves to the position of the shaft to grab it, and delivers the shaft to the position opposite the entrance of the sleeve according to the corrected motion trajectory. Combined with the real-time feedback of the force data from the force control sensor module, the shaft is accurately inserted into the sleeve.

9. A high-precision self-adaptive assembly method for a shaft hole according to claim 8, characterized in that: The navigation method of AGV is as follows: SLAM+PGV composite navigation is adopted, and the dispatching system sends navigation task information to the navigation controller of AGV; the navigation controller first uses SLAM as a navigation sensor, and the navigation controller and the dispatching system continuously feedback the speed and position information to control the AGV to drive along the set route until the positioning feedback of the PGV sensor through the transparent transmission protocol is consistent with the navigation target point. At this time, PGV is switched to as the navigation sensor, and AGV performs closed-loop control according to the PGV feedback information until the positioning position information meets the task requirements, and then transmits the navigation task completion information to the dispatching system, and this navigation task ends.

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