Automatic scraping robot system based on force control

Abstract

The invention discloses an automatic scraping robot system based on force control. The automatic scraping robot system comprises a camera support, a visual camera, a six-degree-of-freedom industrial robot, a workbench, a workpiece, an end effector, a force sensor and a comprehensive control system. Wherein the visual camera is arranged at the top of the camera bracket; the end effector is connected with the six-degree-of-freedom industrial robot through the six-dimensional force sensor; a workpiece is arranged on the workbench; the workpiece is positioned below the visual camera; the comprehensive control system is connected with the visual camera, the six-degree-of-freedom industrial robot and the end effector. And the comprehensive control system carries out regional analysis on the pictures shot by the visual camera to obtain regional coordinates, obtains a robot motion trajectory plan according to the regional coordinates, and controls the end effector and the six-degree-of-freedom industrial robot to move cooperatively according to the robot motion trajectory plan to scrape the workpiece. Manual scraping is replaced, and precise machining of the surfaces of various high-precision structural parts of spacecrafts is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of ultra-precision machining, and in particular relates to an automatic scraping and grinding robot system based on force control. Background Art

[0002] During the development of aerospace optical remote sensors, in order to reduce the impact of remote sensor assembly stress on system accuracy and achieve precise transmission of the optical path, the connection surface accuracy of precision parts such as the remote sensor optical element frame, main load-bearing structural parts, traditional mechanism parts, and space pointing structural parts is relatively high, generally at the micron level.

[0003] In order to achieve the high surface accuracy of the above parts, manual scraping and grinding methods are generally used in production. In traditional manual scraping and grinding, the surface of the part is first cleaned, red lead powder is applied to the end face of the part, and then the end face of the part is ground with a standard plane to find the high point of the end face of the part, and a small amount is removed using a scraping tool. The surface accuracy of the part is achieved by repeating the above process. Therefore, the efficiency of traditional manual scraping and grinding is low, it is not suitable for scraping and grinding of large structural parts, and it has a strong dependence on manual skills and physical fitness. Long-term manual scraping and grinding can easily cause workers to suffer from occupational diseases. In addition, due to inconsistent scraping and grinding skill levels, the quality of parts after scraping and grinding is unstable.

[0004] With the development of remote sensing technology, optical remote sensors are developing towards large-scale, lightweight and stable, which leads to the gradual large-scale, complex and high-precision of remote sensor structures. For the precision processing of large structural parts, traditional manual scraping has process limitations such as difficulty in identifying high and low points, difficulty in self-inspection, and difficulty in removing high points, which cannot achieve scraping of large structural parts. Summary of the invention

[0005] The technical problem solved by the present invention is: to overcome the deficiencies of the prior art and provide an automatic scraping and grinding robot system based on force control to replace manual scraping and grinding, so as to realize the precision machining of the surfaces of various high-precision structural parts of spacecraft.

[0006] The object of the present invention is achieved through the following technical solutions: an automatic scraping and grinding robot system based on force control, comprising: a camera bracket, a visual camera, a six-degree-of-freedom industrial robot, a workbench, a workpiece, an end effector, a force sensor and an integrated control system; wherein the visual camera is arranged on the top of the camera bracket; the end effector is connected to the six-degree-of-freedom industrial robot through the six-dimensional force sensor; the workpiece is arranged on the workbench; the workpiece is located at the bottom of the visual camera; the integrated control system is respectively connected to the visual camera, the six-degree-of-freedom industrial robot and the end effector; the integrated control system performs regional analysis on the photos taken by the visual camera to obtain regional coordinates, obtains the robot motion trajectory planning according to the regional coordinates, and controls the end effector and the six-degree-of-freedom industrial robot to move in coordination according to the robot motion trajectory planning to scrape and grind the workpiece.

[0007] In the above-mentioned automatic scraping robot system based on force control, the integrated control system includes a scraping area analysis module, a scraping trajectory planning module and a collaborative motion control module; wherein the scraping area analysis module performs regional analysis on the photos taken by the visual camera, identifies the regional coordinates, and transmits the regional coordinates to the scraping trajectory planning module; the scraping trajectory planning module receives the regional coordinates, generates the robot motion trajectory planning according to the regional coordinates, and transmits the robot motion trajectory planning to the collaborative motion control module; the collaborative motion control module receives the robot motion trajectory planning, controls the end effector and the six-degree-of-freedom industrial robot to move collaboratively according to the robot motion trajectory planning, and scrapes the workpiece.

[0008] In the above-mentioned automatic scraping and grinding robot system based on force control, the visual camera takes pictures of the grinding condition of the workpiece after the red lead powder is applied.

[0009] In the above-mentioned automatic scraping robot system based on force control, the six-degree-of-freedom industrial robot is used to fix the end effector and move in coordination with the end effector to scrape the area to be scraped on the workpiece.

[0010] In the above-mentioned automatic scraping and grinding robot system based on force control, the workbench is provided with a positioning device, and the positioning device can extract the coordinate position of the workpiece.

[0011] In the above-mentioned automatic scraping and grinding robot system based on force control, a scraper is provided at the end of the end effector.

[0012] In the above-mentioned automatic scraping robot system based on force control, the force loading device and angle adjustment device of the end effector drive the scraper to load the workpiece surface at a preset angle, and when the loading force reaches the set value, the six-degree-of-freedom industrial robot is driven to perform scraping action.

[0013] In the above-mentioned automatic scraping and grinding robot system based on force control, the force sensor monitors the loading force of the scraper.

[0014] A method for automatic scraping and grinding according to an automatic scraping and grinding robot system based on force control, comprising: clamping a workpiece to a workbench; evenly applying red lead powder on the surface of the workpiece, and grinding the surface of the workpiece to be scraped using a reference plate, wherein the area where the red lead powder is ground away is a high point area; a visual camera takes pictures of the surface of the workpiece, and transmits the taken pictures to an integrated control system; a scraping and grinding area analysis module of the integrated control system performs area analysis on the pictures taken by the visual camera, identifies the high point area, and extracts the coordinate values ​​of the high point area; a scraping and grinding trajectory planning module of the integrated control system generates a robot motion trajectory planning according to the scraping and grinding trajectory planning module; and a collaborative motion control module of the integrated control system controls the collaborative motion of an end effector and a six-degree-of-freedom industrial robot according to the robot motion trajectory planning to scrape and grind the workpiece.

[0015] In the above-mentioned automatic scraping method, the collaborative motion control module of the integrated control system controls the collaborative motion of the end effector and the six-degree-of-freedom industrial robot according to the robot motion trajectory planning, and scraping the workpiece includes: placing the scraper at the starting point of the scraping program, setting the angle between the scraper and the workpiece, the single scraping motion speed of the scraper, and the pressure value between the scraper and the workpiece according to the robot motion trajectory planning; adjusting the contact angle between the scraper and the workpiece according to the angle between the scraper and the workpiece through the drive device in the end effector and applying a downward pressure segment displacement until the scraper contacts the workpiece; after the force sensor collects the scraper loading force and reaches the scraper and workpiece pressure value, a motion command is issued to the six-degree-of-freedom industrial robot; the six-degree-of-freedom robot executes all single scraping segment movements at the single scraping motion speed of the scraper according to the robot motion trajectory planning, and all single scraping segments are connected in series to form the robot motion trajectory, wherein the six-degree-of-freedom robot needs to be lifted after completing the single scraping segment scraping.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) The present invention is used to realize parameterized control of the scraping process, replace manual scraping, and realize precision machining of the surfaces of various high-precision structural parts of spacecraft;

[0018] (2) The present invention solves the process limitations of traditional manual scraping, such as difficulty in identifying high and low points, difficulty in self-inspection, and difficulty in removing high points. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0020] Figure 1 is a schematic structural diagram of an automatic scraping and grinding robot system based on force control provided by an embodiment of the present invention;

[0021] Figure 2 is a flow chart of an automatic scraping method of an automatic scraping robot system provided by an embodiment of the present invention;

[0022] Figure 3 is a schematic diagram of a workpiece grinding process provided by an embodiment of the present invention;

[0023] Figure 4 is a schematic diagram of the motion trajectory of a robot provided by an embodiment of the present invention;

[0024] Figure 5 It is a schematic diagram of the motion trajectory of the scraper of a single scraping robot provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] Figure 1 FIG. 1 is a schematic diagram of the structure of an automatic scraping robot system based on force control provided by an embodiment of the present invention. Figure 1 As shown, the automatic scraping and grinding robot system based on force control includes: a camera bracket 1, a visual camera 2, a six-degree-of-freedom industrial robot 3, a workbench 4, a workpiece 5, an end effector 6, a force sensor 7 and an integrated control system; wherein, the visual camera 2 is arranged on the top of the camera bracket 1; the end effector 6 is connected to the six-degree-of-freedom industrial robot 3 through a six-dimensional force sensor 7; the workpiece 5 is arranged on the workbench 4; the workpiece 5 is located at the bottom of the visual camera 2; the integrated control system is respectively connected to the visual camera 2, the six-degree-of-freedom industrial robot 3 and the end effector 6; the integrated control system performs regional analysis on the photos taken by the visual camera to obtain regional coordinates, obtains the robot motion trajectory planning according to the regional coordinates, and controls the end effector and the six-degree-of-freedom industrial robot to move in coordination according to the robot motion trajectory planning to scrape and grind the workpiece 5.

[0027] The integrated control system includes a scraping area analysis module, a scraping trajectory planning module and a collaborative motion control module; wherein the scraping area analysis module performs regional analysis on the photos taken by the visual camera, identifies the regional coordinates, and transmits the regional coordinates to the scraping trajectory planning module; the scraping trajectory planning module receives the regional coordinates, generates a robot motion trajectory plan according to the regional coordinates, and transmits the robot motion trajectory plan to the collaborative motion control module; the collaborative motion control module receives the robot motion trajectory plan, controls the end effector to move collaboratively with the six-degree-of-freedom industrial robot according to the robot motion trajectory plan, and scrapes the workpiece 5.

[0028] Camera bracket 1: Provides stable support for the visual camera system.

[0029] Visual camera 2: Take pictures of the workpiece after red lead powder is applied and collect data.

[0030] Six-degree-of-freedom industrial robot 3: used to fix the end effector and move in coordination with the end effector to scrape the area to be scraped on the workpiece.

[0031] Workbench 5: used for workpiece clamping. A positioning device is set on the workbench to assist in the conversion of workpiece coordinates to robot scraping equipment coordinates.

[0032] End effector 7: A scraper is provided at the end of the end effector. The scraper is driven to load the surface of the part at a certain angle through the force loading device and the angle adjustment device in the end effector. When the loading force reaches the set value, the robot is driven to perform scraping action.

[0033] Force sensor 8: monitors the loading force of the robot scraper blade.

[0034] like Figure 2 As shown, this embodiment also provides a method for automatic scraping and grinding based on a force-controlled automatic scraping and grinding robot system, the method comprising:

[0035] Clamping the workpiece 5 onto the workbench 4;

[0036] Evenly apply red lead powder on the surface of the workpiece 5, and use a reference plate to grind the surface of the workpiece 5 to be scraped, wherein the area where the red lead powder is ground away is the high point area;

[0037] The visual camera 2 takes pictures of the workpiece surface and transmits the pictures to the integrated control system;

[0038] The scraping area analysis module of the integrated control system performs regional analysis on the photos taken by the visual camera, identifies the high point area, and extracts the coordinate values ​​of the high point area;

[0039] The scraping and grinding trajectory planning module of the integrated control system generates the robot motion trajectory planning according to the scraping and grinding trajectory planning module;

[0040] The coordinated motion control module of the integrated control system controls the coordinated motion of the end effector and the six-degree-of-freedom industrial robot according to the robot motion trajectory planning to scrape and grind the workpiece 5.

[0041] The coordinated motion control module of the integrated control system controls the coordinated motion of the end effector and the six-degree-of-freedom industrial robot according to the robot motion trajectory planning, and performs scraping on the workpiece 5, including:

[0042] Place the scraper at the starting point of the scraping program, and set the angle between the scraper and the workpiece, the scraper's single scraping movement speed, and the scraper's pressure value between the workpiece according to the robot's motion trajectory planning;

[0043] The contact angle between the scraper and the workpiece is adjusted according to the angle between the scraper and the workpiece by a driving device in the end effector and a downward pressure segment displacement is applied until the scraper contacts the workpiece;

[0044] After the force sensor collects the scraper loading force and reaches the pressure value between the scraper and the workpiece, a motion command is sent to the six-degree-of-freedom industrial robot;

[0045] The six-degree-of-freedom robot executes all single scraping segment movements at the scraper's single scraping movement speed according to the robot motion trajectory planning. All single scraping segments are connected in series to form the robot motion trajectory. Among them, the six-degree-of-freedom robot needs to be lifted after completing the scraping of a single scraping segment.

[0046] Specifically, the method comprises the following steps:

[0047] Step 1, workpiece clamping: clamp the part to be scraped and ground onto the workbench, and take measures such as raising the part surface to control the distance from the visual camera to a certain range, so that the visual camera can focus and take pictures;

[0048] Step 2: Apply red lead powder: Figure 3 As shown, evenly apply red lead powder on the surface of the workpiece until the surface to be scraped and ground is evenly and fully covered;

[0049] Step 3, workpiece grinding: Figure 3 As shown, the surface to be scraped is ground using a reference plate, and the area where the red lead powder is ground away is the high point area;

[0050] Step 4, visual photography: the visual system takes a photo of the workpiece surface;

[0051] Step 5, analysis of the area to be scraped: Through the scraping area analysis module in the control system, based on the color database, the photos are compared and analyzed to identify the high point area and extract the coordinate value of the high point area;

[0052] Step 6, robot scraping trajectory planning: The scraping trajectory planning module in the control system analyzes the high point area based on the coordinate values ​​obtained in step 5 and automatically generates the robot motion trajectory, such as Figure 4 As shown in the figure, the robot scraping motion trajectory is composed of several single scraping segments.

[0053] Step 7, tool positioning: execute the tool positioning program in the robot scraping, place the scraping tool at the starting point of the scraping program, and simultaneously set the robot scraping process parameters, including the angle between the scraper and the workpiece, the single scraping movement speed of the scraper, the pressure value between the scraper and the workpiece, etc.;

[0054] Step 8, the end effector presses down: the contact angle between the scraping tool and the workpiece is adjusted by the driving device in the end effector and the downward displacement is applied until the tool contacts the workpiece;

[0055] Step 9, the force on the scraper tool reaches the set value: after the six-dimensional force sensor collects the loading force and reaches the set value, a motion instruction is issued to the robot;

[0056] Step 10, robot scraping: The six-degree-of-freedom robot performs a single scraping segment movement until the scraping of this scraping segment is completed and lifted up. The single-point scraping trajectory is as follows Figure 5 All single scraping sections are connected in series to form an attached Figure 4 The robot motion trajectory in the figure is shown in Figure 1. Once the entire trajectory is completed, the scraping is completed.

[0057] Then repeat steps 2 to 5 to check whether the requirements are met. If not, continue scraping until the requirements are met and then end the scraping work.

[0058] This embodiment builds an integrated robot scraping system including detection, high and low point identification, scraping pressure control, automatic trajectory planning, and execution of the scraping process to achieve full automation of the scraping process.

[0059] This embodiment can realize rapid identification of high point areas by setting up an online visual detection system.

[0060] This embodiment integrates the end effector to set process parameters such as scraper angle, scraper movement speed, scraper pressure, etc., thereby realizing a parametrically controlled scraping process and eliminating the influence of the inherent cumulative error of the multi-joint motion of the six-degree-of-freedom process robot on the accuracy of the scraping process.

[0061] 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.

Claims

1. An automatic scraping robot system based on force control, characterized in that include: A camera bracket (1), a visual camera (2), a six-degree-of-freedom industrial robot (3), a workbench (4), a workpiece (5), an end effector (6), a force sensor (7) and an integrated control system; wherein, The visual camera (2) is arranged on the top of the camera bracket (1); The end effector (6) is connected to the six-degree-of-freedom industrial robot (3) via the six-dimensional force sensor (7); The workpiece (5) is arranged on the workbench (4); The workpiece (5) is located below the visual camera (2); The integrated control system is connected to the visual camera (2), the six-degree-of-freedom industrial robot (3) and the end effector (6) respectively; The integrated control system performs regional analysis on the photos taken by the visual camera to obtain regional coordinates, obtains robot motion trajectory planning based on the regional coordinates, and controls the end effector to move in coordination with the six-degree-of-freedom industrial robot based on the robot motion trajectory planning to scrape and grind the workpiece (5).

2. The automatic scraping robot system based on force control according to claim 1 is characterized in that: The integrated control system includes a scraping area analysis module, a scraping trajectory planning module and a coordinated motion control module; wherein, The scraping area analysis module performs area analysis on the photos taken by the visual camera, identifies the area coordinates, and transmits the area coordinates to the scraping trajectory planning module; The scraping trajectory planning module receives the regional coordinates, generates the robot motion trajectory planning according to the regional coordinates, and transmits the robot motion trajectory planning to the collaborative motion control module; The collaborative motion control module receives the robot motion trajectory planning, and controls the end effector to move collaboratively with the six-degree-of-freedom industrial robot according to the robot motion trajectory planning to scrape and grind the workpiece (5).

3. The automatic scraping robot system based on force control according to claim 1 is characterized in that: The visual camera (2) takes pictures of the grinding condition of the workpiece after the red lead powder is applied.

4. The automatic scraping robot system based on force control according to claim 1 is characterized in that: The six-degree-of-freedom industrial robot (3) is used to fix the end effector and move in coordination with the end effector to scrape the area to be scraped on the workpiece.

5. The automatic scraping and grinding robot system based on force control according to claim 1 is characterized in that: The workbench is provided with a positioning device, and the positioning device can extract the coordinate position of the workpiece.

6. The automatic scraping robot system based on force control according to claim 1 is characterized in that: A scraper is arranged at the end of the end effector.

7. The automatic scraping and grinding robot system based on force control according to claim 1 or 6, characterized in that: The force loading device and the angle adjustment device of the end effector drive the scraper to load the workpiece surface at a preset angle, and when the loading force reaches a set value, the six-degree-of-freedom industrial robot is driven to perform a scraping action.

8. The automatic scraping and grinding robot system based on force control according to claim 6 is characterized in that: The force sensor (7) monitors the loading force of the scraper.

9. A method for automatic scraping and grinding based on a force-controlled automatic scraping and grinding robot system according to any one of claims 1 to 8, characterized in that include: Clamping a workpiece (5) onto a workbench (4); Evenly apply red lead powder on the surface of the workpiece (5), and use a reference plate to grind the surface of the workpiece (5) to be scraped, wherein the area where the red lead powder is ground away is the high point area; The visual camera (2) takes a picture of the surface of the workpiece and transmits the taken picture to the integrated control system; The scraping area analysis module of the integrated control system performs regional analysis on the photos taken by the visual camera, identifies the high point area, and extracts the coordinate values ​​of the high point area; The scraping and grinding trajectory planning module of the integrated control system generates the robot motion trajectory planning according to the scraping and grinding trajectory planning module; The coordinated motion control module of the integrated control system controls the coordinated motion of the end effector and the six-degree-of-freedom industrial robot according to the robot motion trajectory planning to scrape and grind the workpiece (5).

10. The automatic scraping method according to claim 9, characterized in that: The coordinated motion control module of the integrated control system controls the coordinated motion of the end effector and the six-degree-of-freedom industrial robot according to the robot motion trajectory planning, and performs scraping and grinding on the workpiece (5) including: Place the scraper at the starting point of the scraping program, and set the angle between the scraper and the workpiece, the scraper's single scraping movement speed, and the scraper's pressure value between the workpiece according to the robot's motion trajectory planning; The contact angle between the scraper and the workpiece is adjusted according to the angle between the scraper and the workpiece by a driving device in the end effector and a downward pressure segment displacement is applied until the scraper contacts the workpiece; After the force sensor collects the scraper loading force and reaches the pressure value between the scraper and the workpiece, a motion command is sent to the six-degree-of-freedom industrial robot; The six-degree-of-freedom robot executes all single scraping segment movements at the scraper's single scraping movement speed according to the robot motion trajectory planning. All single scraping segments are connected in series to form the robot motion trajectory. Among them, the six-degree-of-freedom robot needs to be lifted after completing the scraping of a single scraping segment.

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