Robot quantitative subtractive manufacturing system for composite material workpiece

Abstract

The invention discloses a robot quantitative subtractive manufacturing system for a composite material workpiece. The robot quantitative subtractive manufacturing system comprises an industrial robot unit, a multi-modal information sensor unit, a grinding equipment unit, a material table unit and an upper computer control unit. The industrial robot unit is used for receiving the control instruction sent by the upper computer control unit and completing a corresponding moving track; the multi-modal information sensor unit is used for collecting composite material workpiece information, a surface profile, robot end force and torque information and sending the information to the upper computer control unit; the grinding equipment unit is mounted on the industrial robot unit and driven by the industrial robot unit to finish subtractive manufacturing of the surface of the composite material workpiece; the material platform unit is used for bearing a composite material workpiece; and the upper computer control unit is used for calculating to obtain a target machining area, needing subtractive manufacturing, of the surface of the composite material workpiece, a moving track and a quantized value of subtractive manufacturing according to the received information, generating a corresponding control instruction and sending the control instruction to the industrial robot unit.

Description

Technical Field

[0001] The invention relates to a robot quantitative subtractive manufacturing system for composite material workpieces, belonging to the field of quantitative subtractive manufacturing of composite material workpieces. Background Art

[0002] Composite workpieces are widely used in aerospace, shipbuilding, high-end equipment and other fields due to their unique advantages such as high specific strength, high specific stiffness and corrosion resistance. It is difficult to avoid surface burrs, roughness and even profile deviations in the manufacturing process of composite workpieces. Before further processing or assembly of the workpiece, the composite workpiece needs to be subjected to quantitative subtractive processing. At present, there are two main methods for quantitative subtractive manufacturing of composite workpieces: manual processing and CNC machine tool processing. Manual processing relies on the workers' own skills and abilities, resulting in inconsistent quality and low efficiency of subtractive manufacturing of workpieces. Composite materials are prone to produce a large amount of powder during the processing process, which has an adverse effect on personnel health and environmental protection. CNC machine tool processing has high work efficiency and reduces labor costs, but is limited by the size of the machine tool itself, has clear restrictions on the shape and size of the workpiece, poor flexibility and low flexibility. In addition, the processing accuracy of the machine tool processing method is affected by the accuracy of the machine tool itself, and it is impossible to realize online detection of the workpiece during the processing process, and the quantitative subtractive manufacturing capability for high-precision workpieces is limited.

[0003] In summary, the existing quantitative subtractive systems have strict requirements on workpiece size and poor adaptability to workpiece materials. They are unable to meet the high-precision processing needs of composite workpieces with different configurations, different materials, different volumes, and different precision requirements. The quantitative subtractive manufacturing method has a low level of intelligence and limited versatility, making it difficult to achieve processing of workpieces of various batches, various configurations, and various materials. Summary of the invention

[0004] The technical problem solved by the present invention is: to overcome the deficiencies of the prior art and to provide a robot quantitative subtractive manufacturing system for composite workpieces, which realizes high intelligence, high precision and high flexibility in subtractive manufacturing of composite workpieces by fusing multimodal information sensors.

[0005] The technical solution of the present invention is: a robot quantitative subtractive manufacturing system for composite material workpieces, comprising: an industrial robot unit, a multimodal information sensor unit, a grinding equipment unit, a material table unit and a host computer control unit;

[0006] The industrial robot unit receives control instructions from the host computer control unit and completes the corresponding operation trajectory;

[0007] The multimodal information sensor unit collects composite workpiece information, surface contour, robot end force and torque information, and sends it to the host computer control unit;

[0008] The grinding equipment unit is installed on the industrial robot unit, and driven by the industrial robot unit, it completes the subtractive manufacturing of the surface of the composite workpiece;

[0009] A material table unit, used for carrying composite material workpieces;

[0010] The host computer control unit calculates the target processing area, operation trajectory and quantitative value of subtractive manufacturing on the surface of the composite workpiece based on the received information, and generates corresponding control instructions to send to the industrial robot unit.

[0011] The industrial robot unit comprises a six-degree-of-freedom industrial robot and a robot control cabinet; the six-degree-of-freedom industrial robot is installed on the grinding equipment unit, and the robot control cabinet is arranged on one side of the six-degree-of-freedom industrial robot; the robot control cabinet receives control signals and control commands sent by a host computer control unit, controls the six-degree-of-freedom industrial robot to execute a corresponding operation trajectory, and realizes quantitative subtractive manufacturing of the surface of a composite material workpiece.

[0012] The multimodal information sensor unit includes a binocular depth camera, a six-dimensional force sensor and a line laser scanner;

[0013] The binocular depth camera is installed above the material table unit and equipped with a set of light sources. Before the industrial robot unit works, the binocular depth camera takes pictures of the composite material workpiece fixed on the material table unit to identify the position and type of the workpiece. After the industrial robot unit works, the binocular depth camera collects images of the composite material workpiece again, identifies the processing area and processing effect, and feeds back to the host computer control unit.

[0014] The line laser scanner is installed at the end of the six-degree-of-freedom industrial robot. Before the industrial robot unit works, the line laser scanner scans the surface of the composite workpiece in cooperation with the material table unit to collect information about the composite workpiece. When the industrial robot unit works, the line laser scanner scans the contour of the composite workpiece in real time and feeds back the surface contour data to the host computer control unit in real time.

[0015] The six-dimensional force sensor is installed at the end of the six-degree-of-freedom industrial robot to collect the force and torque data in three directions at the end of the six-degree-of-freedom industrial robot during the subtractive manufacturing process, and feed it back to the host computer control unit.

[0016] The grinding equipment unit comprises a grinding spindle and a flexible joint;

[0017] The grinding spindle utilizes grinding to perform subtractive manufacturing on the surface of a composite material workpiece; the flexible joint is installed between the end of a six-degree-of-freedom industrial robot and the grinding spindle, can float freely within a certain distance, and adapt to slight changes in the shape of the surface, and is used to connect the end flange of the industrial robot and the grinding spindle.

[0018] It also includes a dust collecting device; the dust collecting device is installed around the grinding spindle and collects composite material dust and debris in the subtractive manufacturing process by negative pressure suction.

[0019] The material table unit includes a workpiece loading and unloading device and a workpiece positioning device;

[0020] The workpiece loading and unloading device adopts an open structure to realize the movement and entry and exit of the composite material workpiece on the material table; the workpiece positioning device is arranged at the material table, and clamps and positions the composite material workpiece on the material table through a mechanical structure.

[0021] It also includes a material table rotating device; the material table rotating device is installed at the bottom of the material table unit, and is provided with a rotating table, and the composite material workpiece is fixed on the rotating table; by setting the rotating angle of the rotating table, the rotation of the rotating table drives the composite material workpiece to rotate, ensuring that all areas to be processed of the composite material workpiece on the material table are within the working space of the six-degree-of-freedom industrial robot.

[0022] The host computer control unit includes a workpiece identification and positioning module, a robot trajectory planning module and a quantitative reduction detection module;

[0023] The workpiece identification and positioning module receives the composite workpiece information collected by the binocular depth camera, performs template matching on the information with the workpiece library, obtains the specific composite workpiece type and the target processing state of the workpiece, and then obtains the target processing area on the surface of the composite workpiece that needs to be subtracted and sends it to the robot trajectory planning module;

[0024] The robot trajectory planning module receives the target processing area and obtains the operation trajectory of the robot subtractive manufacturing to the industrial robot unit in combination with the preset process parameters;

[0025] The quantitative subtractive detection module receives the workpiece surface contour status information obtained by real-time scanning by a line laser scanner, as well as the robot end force and torque information during the subtractive manufacturing process monitored in real time by a six-dimensional force sensor. After real-time fusion processing of the above information, the quantitative value of the subtractive manufacturing of the workpiece surface is obtained and transmitted to the industrial robot unit.

[0026] It also includes a safety module; the safety module includes a three-color signal light, an emergency stop button, and a loading and unloading sensor device; the loading and unloading sensor device senses the feeding and unloading status of the material table unit, the three-color signal light is used to indicate the overall status of the system, and the emergency stop button is used to stop the system operation in an emergency to avoid safety accidents.

[0027] It also includes a main control cabinet; the main control cabinet is communicated with the robot control cabinet, the main control cabinet is communicated with the binocular depth camera, the six-dimensional force sensor, and the line laser scanner, and the main control cabinet is communicated with the host computer display.

[0028] The advantages of the present invention compared with the prior art are: the position of the composite material workpiece can be flexibly adjusted through the automated material table rotation device and workpiece positioning device, which can adapt to the positioning and displacement of composite material workpieces of different configurations, avoiding complicated manual labor; the floating device installed between the end of the robot and the grinding spindle can realize the adaptive small shape changes of the workpiece surface, while reducing the impact of the sudden change of the composite material workpiece surface on the robot's movement, and improving the stability of the robot's movement; the quality of the robot's subtractive manufacturing process is monitored in real time through the binocular depth camera, line laser scanner, and six-dimensional force sensor, and the multi-modal sensor information is fused and processed based on the deep learning algorithm to quantitatively characterize the quantitative subtractive manufacturing effect of the composite material workpiece, and the robot's running trajectory is adjusted in real time to realize online monitoring and online correction. In summary, the present invention integrates template matching, image processing, data fusion, deep learning, trajectory planning and other related technologies and methods, and finally realizes high-intelligence and high-precision subtractive manufacturing of composite material workpieces. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the robot quantitative subtractive manufacturing system for composite material workpieces according to the present invention.

[0030] Figure 2 This is a control flow chart of the robot quantitative subtractive manufacturing system of the present invention. DETAILED DESCRIPTION

[0031] The robot quantitative subtractive manufacturing system for composite workpieces of the present invention is intended to solve the high-precision quantitative subtractive manufacturing of composite workpiece surfaces with non-specific shapes. It combines multi-sensor fusion, three-dimensional reconstruction, and robot trajectory planning technology to realize online monitoring and online correction of subtractive manufacturing of composite workpieces. It is an automated subtractive manufacturing system with high intelligence, high working precision, and good flexibility.

[0032] The system of the present invention mainly comprises an industrial robot unit, a multimodal information sensor unit, a grinding equipment unit, a material table unit and a host computer control unit.

[0033] like Figure 1Shown is a schematic diagram of a robotic quantitative subtractive manufacturing system for composite workpieces.

[0034] The industrial robot unit comprises a six-degree-of-freedom industrial robot 11 and a robot control cabinet 12;

[0035] The multimodal information sensor unit includes a binocular depth camera 21, a six-dimensional force sensor 22 and a line laser scanner 24;

[0036] The binocular depth camera is installed above the material table and is equipped with a set of special light sources 23;

[0037] The grinding equipment unit includes a composite material-specific grinding spindle 31, a flexible joint 32, and a dust collecting device 34;

[0038] The dust collecting device 34 collects the composite material dust and debris in the subtractive manufacturing process by suction through the negative pressure suction head 33;

[0039] The material table unit includes a workpiece loading and unloading device 42, a workpiece positioning device 41 and a material table rotating device 43;

[0040] The host computer control unit includes a master control module, a workpiece identification and positioning module, a robot trajectory planning module, a quantitative material reduction detection module and a safety module.

[0041] The host computer control unit is integrated into the main control cabinet 51, and information interaction and display are performed through the host computer display 52;

[0042] The safety module includes a three-color signal light 53 , an emergency stop button 54 , and a loading and unloading sensor device 55 , and the three-color signal light 53 is used to display the overall safety status of the system.

[0043] In this embodiment, for the robot quantitative subtractive manufacturing system for composite workpieces, the six-degree-of-freedom industrial robot 11 is installed on the end grinding spindle 31 to realize quantitative subtractive manufacturing of the composite workpiece surface of non-specific configuration workpieces, where non-specific configuration workpieces include but are not limited to rotating bodies. The system determines the type of composite workpiece and the area to be processed by the workpiece through the binocular depth camera 21 and the line laser scanner 22, and then determines the operation trajectory of the quantitative subtractive manufacturing of the six-degree-of-freedom industrial robot 11. When the workpiece needs to be replaced, the loading and unloading device 42 of the material table is started, and the binocular depth camera 21 and the line laser scanner 22 re-scan the new workpiece to generate a new robot operation trajectory, without the need for manual programming, and with a higher degree of intelligence.

[0044] It also includes a robot control cabinet 12, which is provided on one side of the six-degree-of-freedom industrial robot 11. In this embodiment, the robot control 12 is connected to the six-degree-of-freedom industrial robot 11 for controlling the six-degree-of-freedom industrial robot 11 to execute a corresponding trajectory according to a control command of the host computer control unit.

[0045] It also includes a binocular depth camera 21, a six-dimensional force sensor 22, and a line laser scanner 24. In this embodiment, the binocular depth camera 21 takes pictures of the composite material workpiece fixed on the material table to identify the workpiece position, workpiece type and processing area; the line laser scanner 24 is installed at the end of the robot to scan the surface of the composite material workpiece, collect and feedback the workpiece surface contour data in real time; the six-dimensional force sensor 23 is installed at the end of the six-degree-of-freedom industrial robot 11, collects the force and torque data in three directions in real time during the operation of the robot, and feeds back to the host computer control unit.

[0046] It also includes a negative pressure suction head 33 and a dust collecting device 34 under the material table unit. In this embodiment, the negative pressure suction head 33 and the dust collecting device 34 are high-power negative pressure generators, which can quickly recover dust and debris generated during the subtractive manufacturing process of composite material workpieces to avoid pollution to the environment.

[0047] The material table rotating device 43 is also included. The material table rotating device 43 is arranged at the bottom of the material table unit, drives the material table unit to rotate, and is connected to the main control cabinet 51. In this embodiment, by setting the material table rotation angle, the material table rotation drives the workpiece to rotate, ensuring that all the areas to be processed of the composite material workpiece on the material table are within the working space range of the six-degree-of-freedom industrial robot 11.

[0048] It also includes a three-color signal light 53, an emergency stop button 54, and a loading and unloading sensor device 55. In this embodiment, the three-color signal light 53 uses green, yellow, and red to represent the three states of normal operation, dangerous operation, and fault alarm of the system; the emergency stop button 54 can stop the system operation in an emergency to avoid safety accidents; the loading and unloading sensor device 55 senses the feeding and unloading states of the loading and unloading platform.

[0049] It also includes a main control cabinet 51, which is located above the robot control cabinet 12, and the main control cabinet 51 is connected to the robot control cabinet 12 for communication, the main control cabinet 51 is connected to the binocular depth camera 21, the six-dimensional force sensor 22, and the line laser scanner 23 for communication, and the main control cabinet 51 is connected to the host computer display 52 for communication. In this embodiment, the main control cabinet 51 fuses, calculates, and analyzes the depth image data taken by the binocular depth camera 21, the robot end force signal data collected by the six-dimensional force sensor 22, and the workpiece surface contour data obtained by the line laser scanner 23, and outputs the six-degree-of-freedom industrial robot 11 running trajectory instructions. The main control cabinet realizes online monitoring of the quantitative subtractive manufacturing process of composite workpieces through multi-sensor modal data fusion, and the real-time nature of the deep learning algorithm ensures real-time correction of the robot's running trajectory.

[0050] like Figure 2 Shown is a control flow chart of the robot quantitative subtractive manufacturing system of the present invention.

[0051] The first step is to turn on the master control module and power on the system;

[0052] In the second step, the master control module controls the loading device 42 of the material table unit: the composite material workpiece is placed on the material table, and the workpiece positioning device 41 is started to fix the workpiece on the rotary material table;

[0053] In the third step, the master control module controls the material table unit rotating device 43: starts the material table rotation, and rotates a fixed angle each time to ensure that the composite material workpiece is in a proper position in the robot workspace;

[0054] Step 4: Start the workpiece identification and positioning module: After the composite material workpiece is fixed, turn on the camera light source 23 for supplementary light, and start the binocular depth camera 21 to collect workpiece images; after the collection is completed, turn off the camera light source 23;

[0055] The fifth step is to process the collected workpiece image: use the workpiece image containing depth information to perform three-dimensional reconstruction of the workpiece, obtain a three-dimensional digital model of the workpiece to be processed, and perform template matching with the standard three-dimensional digital model in the workpiece library to determine the type of composite material workpiece to be processed and the area of ​​the workpiece to be processed; if the template matching fails, a failure message is returned, and the yellow light in the three-color signal light 53 flashes;

[0056] Step 6: The main control unit calculates the planned processing area: the planned processing area of ​​the workpiece surface is obtained based on the processing area of ​​the composite workpiece obtained in the previous step and the robot working space range;

[0057] Step 7: Start the robot trajectory planning module: grid the area to be processed, parameterize the surface information to be processed, and generate the robot trajectory according to the set subtractive manufacturing process parameters, including but not limited to surface roughness, grinding feed rate and other parameters;

[0058] In the eighth step, the main control unit starts the grinding spindle 31 and the negative pressure suction head 33, and the robot moves according to the trajectory generated in the previous step;

[0059] The ninth step is to start the quantitative subtraction detection module: start the line laser scanner 24 and the six-dimensional force sensor 22; the line laser scanner 24 scans the processing area in real time, and performs high-precision three-dimensional reconstruction, and obtains the quantitative value of the surface of the subtractive manufacturing area, and compares and judges with the set value; the six-dimensional force sensor monitors the changes of the grinding spindle force and torque in real time, and uses the impedance control algorithm to track and control the force and torque information in real time;

[0060] In the tenth step, the master control unit adjusts the robot's running trajectory online: using the deep learning algorithm to fuse the data of the line laser scanner 24 and the six-dimensional force sensor 22, and compare the set quantitative value of subtractive manufacturing and the tracking value of force and torque; if the target value is met, proceed to the next step; if not, adjust the robot's running trajectory in real time to meet the target value;

[0061] In the eleventh step, the binocular depth camera 21 is started again to collect images of the composite material workpiece and perform three-dimensional reconstruction to determine whether the processing of all the areas to be processed is completed; if not, the third step is entered; if satisfied, the next step is entered;

[0062] In the twelfth step, the master control module starts unloading: the master control module closes the workpiece positioning device 41 and releases the workpiece; the unloading device is started, and the subtractive manufacturing of the composite material workpiece is completed.

[0063] 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 can make possible changes and modifications to the technical solution of the present invention by using the 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. A robot quantitative subtractive manufacturing system for composite material workpieces, characterized in that: include: Industrial robot unit, multimodal information sensor unit, grinding equipment unit, material table unit and host computer control unit; The industrial robot unit receives control instructions from the host computer control unit and completes the corresponding operation trajectory; The multimodal information sensor unit collects composite workpiece information, surface contour, robot end force and torque information, and sends it to the host computer control unit; The grinding equipment unit is installed on the industrial robot unit, and driven by the industrial robot unit, it completes the subtractive manufacturing of the surface of the composite workpiece; A material table unit, used for carrying composite material workpieces; The host computer control unit calculates the target processing area, operation trajectory and quantitative value of subtractive manufacturing on the surface of the composite workpiece based on the received information, and generates corresponding control instructions to send to the industrial robot unit.

2. A robot quantitative subtractive manufacturing system for composite material workpieces according to claim 1, characterized in that: The industrial robot unit comprises a six-degree-of-freedom industrial robot and a robot control cabinet; the six-degree-of-freedom industrial robot is installed on the grinding equipment unit, and the robot control cabinet is arranged on one side of the six-degree-of-freedom industrial robot; the robot control cabinet receives control signals and control commands sent by a host computer control unit, controls the six-degree-of-freedom industrial robot to execute a corresponding operation trajectory, and realizes quantitative subtractive manufacturing of the surface of a composite material workpiece.

3. A robot quantitative subtractive manufacturing system for composite material workpieces according to claim 2, characterized in that: The multimodal information sensor unit includes a binocular depth camera, a six-dimensional force sensor and a line laser scanner; The binocular depth camera is installed above the material table unit and equipped with a set of light sources. Before the industrial robot unit works, the binocular depth camera takes pictures of the composite material workpiece fixed on the material table unit to identify the position and type of the workpiece. After the industrial robot unit works, the binocular depth camera collects images of the composite material workpiece again, identifies the processing area and processing effect, and feeds back to the host computer control unit. The line laser scanner is installed at the end of the six-degree-of-freedom industrial robot. Before the industrial robot unit works, the line laser scanner scans the surface of the composite workpiece in cooperation with the material table unit to collect information about the composite workpiece. When the industrial robot unit works, the line laser scanner scans the contour of the composite workpiece in real time and feeds back the surface contour data to the host computer control unit in real time. The six-dimensional force sensor is installed at the end of the six-degree-of-freedom industrial robot to collect the force and torque data in three directions at the end of the six-degree-of-freedom industrial robot during the subtractive manufacturing process, and feed it back to the host computer control unit.

4. The robot quantitative subtractive manufacturing system for composite material workpieces according to claim 1, characterized in that: The grinding equipment unit comprises a grinding spindle and a flexible joint; The grinding spindle utilizes grinding to perform subtractive manufacturing on the surface of a composite material workpiece; the flexible joint is installed between the end of a six-degree-of-freedom industrial robot and the grinding spindle, can float freely within a certain distance, and adapt to slight changes in the shape of the surface, and is used to connect the end flange of the industrial robot and the grinding spindle.

5. A robot quantitative subtractive manufacturing system for composite material workpieces according to claim 4, characterized in that: It also includes a dust collecting device; the dust collecting device is installed around the grinding spindle and collects composite material dust and debris in the subtractive manufacturing process by negative pressure suction.

6. The robot quantitative subtractive manufacturing system for composite material workpieces according to claim 1, characterized in that: The material table unit includes a workpiece loading and unloading device and a workpiece positioning device; The workpiece loading and unloading device adopts an open structure to realize the movement and entry and exit of the composite material workpiece on the material table; the workpiece positioning device is arranged at the material table, and clamps and positions the composite material workpiece on the material table through a mechanical structure.

7. A robot quantitative subtractive manufacturing system for composite material workpieces according to claim 6, characterized in that: It also includes a material table rotating device; the material table rotating device is installed at the bottom of the material table unit, and is provided with a rotating table, and the composite material workpiece is fixed on the rotating table; by setting the rotating angle of the rotating table, the rotation of the rotating table drives the composite material workpiece to rotate, ensuring that all areas to be processed of the composite material workpiece on the material table are within the working space of the six-degree-of-freedom industrial robot.

8. The robot quantitative subtractive manufacturing system for composite material workpieces according to claim 1, characterized in that: The host computer control unit includes a workpiece identification and positioning module, a robot trajectory planning module and a quantitative reduction detection module; The workpiece identification and positioning module receives the composite workpiece information collected by the binocular depth camera, performs template matching on the information with the workpiece library, obtains the specific composite workpiece type and the target processing state of the workpiece, and then obtains the target processing area on the surface of the composite workpiece that needs to be subtracted and sends it to the robot trajectory planning module; The robot trajectory planning module receives the target processing area and obtains the operation trajectory of the robot subtractive manufacturing to the industrial robot unit in combination with the preset process parameters; The quantitative subtractive detection module receives the workpiece surface contour status information obtained by real-time scanning by a line laser scanner, as well as the robot end force and torque information during the subtractive manufacturing process monitored in real time by a six-dimensional force sensor. After real-time fusion processing of the above information, the quantitative value of the subtractive manufacturing of the workpiece surface is obtained and transmitted to the industrial robot unit.

9. The robot quantitative subtractive manufacturing system for composite material workpieces according to claim 8, characterized in that: It also includes a safety module; the safety module includes a three-color signal light, an emergency stop button, and a loading and unloading sensor device; the loading and unloading sensor device senses the feeding and unloading status of the material table unit, the three-color signal light is used to indicate the overall status of the system, and the emergency stop button is used to stop the system operation in an emergency to avoid safety accidents.

10. The robot quantitative subtractive manufacturing system for composite material workpieces according to claim 3, characterized in that: It also includes a main control cabinet; the main control cabinet is communicated with the robot control cabinet, the main control cabinet is communicated with the binocular depth camera, the six-dimensional force sensor, and the line laser scanner, and the main control cabinet is communicated with the host computer display.

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