A robot quick-change plate docking online self-correction system and method based on in-situ scanning

Abstract

The present invention relates to the field of robot control technology, and discloses an online self-correction system and method for robot quick-change disk docking based on in-situ scanning. The system includes a host computer, a working robot system, a quick-change disk system, a scanning measurement system, and a calibration system; the host computer integrates an online self-correction system control unit ECU and a scanning measurement controller, and the online self-correction system control unit ECU is connected to the working robot system and the scanning measurement system respectively through signal lines. The present invention can accurately identify the position offset of the quick-change disk and the normal vector offset angle of the docking disk surface, and then adaptively control the robot end mother disk to adjust the angle and docking displacement, solving the low accuracy and time-consuming problem of the traditional teaching method to calibrate the robot tool coordinate system, and can effectively improve the rapid calibration of the robot quick-change disk plug-in coordinate system.

Description

Technical Field

[0001] The present invention relates to the field of robot control technology, and in particular to an online self-correction system and method for robot quick-change plate docking based on in-situ scanning. Background Art

[0002] Currently, robotic workstations in flexible, multi-product production lines, such as those used in welding, robotic assembly, and gluing stations for automobile body and new energy battery manufacturing, and in other robotic automated manufacturing scenarios, often integrate multiple processes. Multi-task robot task switching primarily involves swapping between different workcarriers. These workcarriers are typically equipped with unified interfaces to facilitate automated connection to the robot's end-of-line interface. The robot's end-of-line interface uses a shared master tray, while different workcarriers are equipped with slave trays. Switching between these two trays is accomplished by simply plugging the master tray into the slave tray. The electrical interfaces of the master tray and the slave tray require high precision to ensure reliable connection and airtightness. However, due to the limitations of robot positioning accuracy, the slave trays are typically placed on a support frame using a floating positioning method. This ensures that the carrier connected to the slave tray can accommodate oscillation during robot placement, ensuring that the master tray can be inserted into the slave tray's positioning holes under the applied force. This method ensures reliable master tray docking during mass production, but it also increases wear and tear on the master tray docking, leading to failure if the floating amount exceeds the limit. Therefore, the key is to adaptively adjust the docking position and posture of the mother disk within the floating error range when the daughter disk is placed on the support frame according to the actual position and posture of the daughter disk, so as to ensure that the mother and daughter disks are in a stress-free assembly state when plugged in, ensure the reliability and accuracy of the plug-in, and reduce the plug-in stress and wear.

[0003] Currently, the docking of parent and daughter discs at the end of a robot primarily relies on a teach-in method. The parent disc at the end of the robot plugs into the daughter disc in a fixed trajectory and position, making it difficult to ensure accurate docking multiple times. However, as mixed-line processing of multiple products becomes the mainstream production model, the use of robotic quick-change discs to connect and replace carriers will increase. Ensuring stable docking and batch accuracy during mass production becomes a major challenge. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art. The present invention is aimed at the mother-and-child disk plug-in process of the multiple robot end quick-change system, and invents an online self-correction system and method for robot quick-change disk docking based on in-situ scanning. The system can track the plug-in feature position of the scanned target sub-disk in real time, and through online self-correction, adaptively adjust the position and posture of the mother disk docking with the sub-disk to ensure the accuracy of multiple plug-in of the mother-and-child disk under the floating support of the sub-disk.

[0005] One objective of the present invention is achieved through the following technical solutions: a robot quick-change disk docking online self-correction system based on in-situ scanning, comprising a host computer, a working robot system, a quick-change disk system, a scanning measurement system and a calibration system; the working robot system comprises a robot and a robot controller, and the robot end is used to install a quick-change mother disk and a corresponding electrical interface; the quick-change disk system comprises a quick-change mother disk, a quick-change sub-disk and a parking bracket for placing the quick-change sub-disk; the scanning measurement system comprises a scanning measuring instrument and a scanning measurement controller, and the scanning measurement system is installed at the end of the robot and is consistent with the orientation of the quick-change mother disk; the calibration system comprises a calibration block, a support bracket, and a flexible clamping tool, and the calibration block is fixed on the flexible clamping tool through the support bracket, and the flexible clamping tool is installed near the quick-change sub-disk; the host computer integrates an online self-correction system control unit ECU and a scanning measurement controller, and the online self-correction system control unit ECU is connected to the robot controller and the scanning measurement controller respectively through signal lines.

[0006] Another object of the present invention is achieved through the following technical solution: a method for online self-correction of robot quick-change plate docking based on in-situ scanning, comprising the following steps:

[0007] Step 1: Design the CAD model of the theoretical calibration block and the quick-change master assembly, and obtain the conversion relationship between the robot end quick-change master and the theoretical calibration block coordinate system. The coordinate system of the theoretical calibration block at the robot end is expressed as: Oxyz_{calibration block CAD} = ×Oxyz_{robotendCAD}; Then locate the theoretical calibration block and record the current robot position. Set the coordinate system of the current calibration block to the robot tool coordinate system and bind it to achieve the associated mapping between the robot coordinate system and the calibration block coordinate system. Complete the robot coordinate system calibration based on the theoretical calibration block, which serves as the reference coordinate system for the correction trajectory of the robot end quick-change motherboard insertion.

[0008] Step 2: Fix the calibrated calibration block, move the robot away from the calibration block, and the online self-correction system control unit ECU controls the robot controller to start and perform the following controls: Control the robot controller to execute the robot scanning program, drive the scanning measurement system to scan the calibration block and the target quick change sub-plate respectively; Control the scanning measurement controller to start scanning, and obtain the measurement point cloud data of the calibration block and the target quick change sub-plate during the robot's mobile measurement process ; Then, the target quick change sub-plate deviation is identified and the surface point cloud of the target quick change sub-plate is selected , respectively extract the target quick-change sub-plate surface normal vector and the hole coordinate information of the quick-change sub-plate guide hole feature; calibrate the block point cloud data Surface point cloud of target quick-change disk The relative position calculation can obtain the local coordinate system transformation matrix of the two, which can be recorded as ;

[0009] Step 3: First, calculate the target quick-change sub-plate insertion position. Based on the calibrated calibration block position and the deviation of the target quick-change sub-plate relative to the calibration block, calculate the actual position of the target quick-change sub-plate relative to the calibration block. = ; Then the online self-correction system control unit ECU combines the calculation to obtain the relative position of the target quick-change sub-disk, and converts the target quick-change sub-disk position into the displacement of the relative calibration block expressed in the robot tool coordinate system; Finally, the online self-correction system control unit ECU combines the current point cloud of the target quick-change sub-disk , obtain the actual position information and end face normal vector of the current quick-change sub-disk, and the online self-correction system control unit ECU generates the corresponding stress-free plug-in robot trajectory control program based on the actual position information and end face normal vector, and then controls the robot to drive its end quick-change mother disk to complete the plug-in task of the quick-change sub-disk.

[0010] Preferably, the method further includes the following steps: first, for the actual working condition in which the target quick-change sub-plate has slight changes during multiple plug-in processes, based on the initial adaptive teaching to generate the trajectory, the robot controller is started to execute the robot scanning program, driving the robot end scanning measuring instrument to scan and obtain the point cloud data of the target quick-change sub-plate and the calibration block after the slight changes. Then, the online self-correction system control unit ECU combines the reference coordinate system determination process of the robot end quick change mother disk insertion correction trajectory, the floating quick change sub-disk deviation error identification process and the insertion position update and adaptive insertion process to calculate the target quick change sub-disk position = , relative to the initial position The change vector ;Online self-correction system control unit ECU according to the small change vector The offset position and normal vector change of the target quick-change sub-plate relative to the initial position are calculated. The online self-correction system control unit ECU combines the calculated offset position and normal vector change, updates the robot execution program of the target point online based on the initial docking trajectory program, and sends the updated new robot execution program to the robot controller, driving the robot to execute the docking trajectory updated by the online self-correction, thereby realizing rapid self-correction and automatic docking adjustment based on online micro-displacement recognition.

[0011] The beneficial effects of the present invention are as follows:

[0012] 1. The present invention proposes an online self-correction system for quick-change plate docking of robots based on in-situ scanning. Through the in-situ scanning system integrated at the end of the robot, the displacement deviation of the floating quick-change plate relative to the calibration block can be identified online, and the position offset of the quick-change plate and the normal vector offset angle of the docking plate surface can be accurately identified. Then, the adjustment angle and docking displacement of the mother plate at the end of the robot can be adaptively controlled to avoid the influence of the offset caused by floating placement on the docking accuracy of the mother and child plates.

[0013] 2. The present invention proposes to design a standard calibration block and quickly fix the calibration block through a flexible clamping tool for the calibration block, and combine it with the conversion of CAD digital model to quickly realize the deployment of the calibration block and the calibration conversion of the coordinate system, so as to solve the low accuracy and time-consuming problem of the traditional teaching method for calibrating the robot tool coordinate system, and can effectively improve the rapid calibration of the robot quick-change disk plug-in coordinate system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the structure of the online self-correction system for quick-change plate docking of robots based on in-situ scanning according to an embodiment of the present invention.

[0015] Figure 2 This is a flow chart of an online self-correction method for robot quick-change plate docking based on in-situ scanning according to an embodiment of the present invention.

[0016] In the figure, 1. Host computer; 2. Robot; 3. Robot controller; 4. Quick-change mother plate; 5. Quick-change daughter plate; 6. Parking bracket; 7. Scanning measuring instrument; 8. Calibration block; 9. Flexible clamping tooling. DETAILED DESCRIPTION

[0017] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific embodiments. The accompanying drawings are for illustrative purposes only and are schematic, not actual, representations. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some components in the accompanying drawings may be omitted, enlarged, or reduced in size, and do not represent the dimensions of actual products. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted from the accompanying drawings.

[0018] Example 1:

[0019] like Figure 1As shown, the present invention provides an online self-correcting system for robot quick-change disk docking based on in-situ scanning, comprising a host computer 1, a working robot system, a quick-change disk system, a scanning measurement system and a calibration system; the working robot system comprises a robot 2 and a robot controller 3, and the end of the robot 2 is used to install a quick-change mother disk 4 and a corresponding electrical interface; the quick-change disk system comprises a quick-change mother disk 4, a quick-change sub-disk 5 and a parking bracket 6 for placing the quick-change sub-disk; the scanning measurement system comprises a scanning measuring instrument 7 and a scanning measurement controller, and the scanning measurement system is installed at the end of the robot 2 and is consistent with the orientation of the quick-change mother disk 4; the calibration system comprises a calibration block 8, a support bracket, and a flexible clamping tool 9, and the calibration block 8 is fixed on the flexible clamping tool 9 through the support bracket, and the flexible clamping tool 9 is installed on the parking bracket 6 near the quick-change sub-disk 5; the host computer 1 integrates an online self-correcting system control unit ECU and a scanning measurement controller, and the online self-correcting system control unit ECU is connected to the robot controller 3 and the scanning measurement controller respectively through signal lines.

[0020] Example 2:

[0021] Combine Figure 1 and Figure 2 This embodiment provides a method for online self-correction of robot quick-change plate docking based on in-situ scanning, which is applied to the online self-correction system for robot quick-change plate docking based on in-situ scanning mentioned in Example 1. Specifically, this method includes the following steps:

[0022] Step 1: First, design a theoretical calibration block 8 that includes hole positioning features and a tapered hole feature that cooperates with the positioning taper pin of the quick-change master 4. Then, design a CAD model of the assembly of the theoretical calibration block 8 and the quick-change master 4. This allows us to obtain the conversion relationship between the quick-change master 4 at the end of the robot 2 and the calibration block 8 coordinate system. The coordinate system of the calibration block 8 at the end of the robot 2 is expressed as: Oxyz_{calibration block CAD} = ×Oxyz_{robotendCAD}. Then, the theoretical calibration block 8 is positioned. The positioning process is as follows: Assemble the theoretical calibration block 8 and the quick-change master disc 4 according to the designed assembly position. Control the robot 2 to move the calibration block 8 to the calibration block 8 flexible clamping fixture 9 placed near the support frame of the quick-change sub-disc 5. Place the calibration block 8 into the calibration block 8 flexible clamping fixture 9 via the calibration block 8 support bracket connected to the special calibration block 8. Tighten the calibration block 8 flexible clamping fixture 9 to lock the position of the calibration block 8 support bracket. Afterwards, record the current position of the robot 2, set the coordinate system Oxyz of the current calibration block 8 to the robot tool coordinate system and bind it, realize the association mapping between the robot coordinate system and the calibration block coordinate system, and complete the robot coordinate system calibration based on the theoretical calibration block. This serves as the reference coordinate system for the insertion and correction trajectory of the quick-change master disc 4 at the end of the robot 2.

[0023] Step 2: First, fix the calibrated calibration block 8, move the robot 2 away from the calibration block 8, and the online self-correction system control unit ECU controls the robot controller 3 to start and perform the following controls: control the robot controller 3 to execute the robot scanning program, drive the scanning measurement system to scan the calibration block 8 and the target quick-change sub-disc 5 respectively; control the scanning measurement controller to start scanning, and obtain the measurement point cloud data of the calibration block 8 and the target quick-change sub-disc 5 during the movement measurement process of the robot 2 Then, the target quick-change sub-disk 5 deviation is identified, and the surface point cloud of the target quick-change sub-disk 5 is selected. , respectively extract the surface normal vector of the target quick-change sub-plate 5 and the hole coordinate information of the guide hole feature of the quick-change sub-plate 5; calibrate the point cloud data of block 8 Surface point cloud of target quick-change disk 5 The relative position calculation can obtain the local coordinate system transformation matrix of the two, which can be recorded as .

[0024] Step 3: First, calculate the target quick-change sub-disc 5 insertion position. Based on the calibrated position of the calibration block 8 and the deviation of the target quick-change sub-disc 5 from the calibration block 8, calculate the actual position of the target quick-change sub-disc 5 relative to the calibration block 8. = Then, the online self-correction system control unit ECU combines the calculation to obtain the relative position of the target quick-change sub-disc 5, and converts the position of the target quick-change sub-disc 5 into the displacement of the relative calibration block 8 expressed in the robot tool coordinate system. Finally, the online self-correction system control unit ECU combines the current point cloud of the target quick-change sub-disc 5 , obtain the actual position information and end face normal vector of the current quick-change sub-disk 5, and the online self-correction system control unit ECU generates the corresponding stress-free plugging robot trajectory control program based on the actual position information and end face normal vector, and then controls the robot 2 to drive its end quick-change mother disk 4 to complete the plugging task of the quick-change sub-disk 5.

[0025] In order to achieve accurate positioning after multiple plugging, the following steps are further included: First, in view of the actual working condition that the target quick-change sub-disc 5 has slight changes during multiple plugging, based on the initial adaptive teaching to generate the trajectory, the robot controller 3 is started to execute the robot scanning program, driving the end-end scanning measuring instrument 7 of the robot 2 to scan and obtain the point cloud data of the target quick-change sub-disc 5 and the calibration block 8 after slight changes. Then, the online self-correction system control unit ECU combines the reference coordinate system of the robot 2 end quick change mother plate 4 insertion correction trajectory, the floating quick change sub-plate 5 deviation error recognition process and the insertion position update and adaptive insertion process to calculate the target quick change sub-plate 5 position after a small change = . And calculate the position of the quick change sub-disk 5 relative to the initial position after a small change The change vector ;Online self-correction system control unit ECU according to the small change vector The offset position and normal vector change of the target quick-change sub-disk 5 relative to the initial position are calculated. The online self-correction system control unit ECU combines the calculated offset position and normal vector change, updates the robot execution program of the target point online based on the initial docking trajectory program, and sends the updated new robot execution program to the robot controller 3, driving the robot 2 to execute the docking trajectory updated by the online self-correction, thereby realizing rapid self-correction and automatic docking adjustment based on online micro-displacement recognition.

[0026] The above are only preferred specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with this technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solutions and inventive concepts of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for online self-correction of robot quick-change plate docking based on in-situ scanning, characterized in that: The following steps are involved: Step 1. Determine the reference coordinate system of the robot (2) end quick-change master (4) insertion correction trajectory: Design a CAD model of the theoretical calibration block (8) and the quick-change master (4) assembly, and obtain the transformation matrix of the robot (2) end quick-change master (4) relative to the theoretical calibration block (8) coordinate system: ; Position the calibration block (8), record the current position of the robot (2), set the coordinate system of the current calibration block (8) to the tool coordinate system of the robot (2) and bind it, and complete the calibration of the robot (2) coordinate system of the theoretical calibration block (8); Step 2, identification of deviation error of floating quick-change sub-disc (5): fix the calibration block (8), control the robot (2) to drive the scanning measuring instrument (7) to scan the calibration block (8) and the target quick-change sub-disc (5), and start the scanning measuring instrument (7) to obtain the measurement point cloud data of the calibration block (8) and the target quick-change sub-disc (5); select the surface point cloud data of the target quick-change sub-disc (5), extract its normal vector and the hole position coordinate information of the guide hole feature, calculate the relative position of the calibration block (8) point cloud data and the surface point cloud data of the target quick-change sub-disc (5), and obtain the local coordinate system conversion matrix of the two; Step 3: Generate an initial docking trajectory program to achieve plug-in position update and adaptive plug-in: Based on the calibrated calibration block (8) position and the deviation of the target quick-change sub-disc (5) relative to the calibration block (8), calculate the actual position of the target quick-change sub-disc (5) relative to the calibration block (8), and further obtain the relative position of the target quick-change sub-disc (5), which is converted into the displacement relative to the calibration block (8) expressed in the tool coordinate system of the robot (2); Combined with the actual position and displacement of the target quick-change sub-disc (5) relative to the calibration block (8), the actual position information and end face normal vector of the current quick-change sub-disc (5) are obtained, and the online self-correction system control unit ECU generates a corresponding stress-free plug-in robot (2) trajectory control program, thereby controlling the robot (2) to drive its terminal quick-change mother disc (4) to complete the plug-in task of the quick-change sub-disc (5); The step three further includes small change detection and automatic correction: based on the initial adaptive teaching trajectory generation, the robot (2) scanning program is started, and the scanning measuring instrument (7) obtains the point cloud data of the target quick-change sub-disc (5) and the calibration block (8) after the small change; the online self-correction system control unit ECU combines the reference coordinate system determination process of the robot (2) end quick-change mother disc (4) plug-in correction trajectory, the floating quick-change sub-disc (5) deviation error recognition process and the plug-in position update and adaptive plug-in process to calculate the small change vector of the target quick-change sub-disc (5) position relative to the initial position after the change. ; According to the small change vector The offset position and normal vector change of the target quick-change sub-disc (5) relative to the initial position are calculated; and the robot (2) executes the program to update the target point based on the initial docking trajectory program.

2. The method for online self-correction of robot-robot quick-change disk docking based on in-situ scanning according to claim 1 is characterized in that: The theoretical calibration block (8) in step 1 is a calibration block (8) comprising a hole positioning feature and a tapered hole feature capable of cooperating with a positioning tapered pin of the quick-change master disc (4).

3. The method for online self-correction of robot-robot quick-change disk docking based on in-situ scanning according to claim 1 is characterized in that: The process of positioning the calibration block (8) in the step 1 is as follows: assemble the theoretical calibration block (8) and the quick-change mother disc (4) according to the designed assembly position, control the robot (2) to move the calibration block (8) to the flexible clamping fixture (9) of the calibration block (8) placed near the support frame of the quick-change sub-disc (5), place the calibration block (8) into the flexible clamping fixture (9) of the calibration block (8) through the calibration block (8) support bracket connected to the special calibration block (8), and tighten the flexible clamping fixture (9) of the calibration block (8) to lock the position of the calibration block (8) support bracket.

4. The method for online self-correction of robot-robot quick-change disk docking based on in-situ scanning according to claim 1 is characterized in that: In the step 2, the measured point cloud data of the calibration block (8) and the target quick-change sub-disc (5) are recorded as , the local coordinate system transformation matrix of the calibration block (8) and the target quick-change disk (5) is .

5. The method for online self-correction of robot-robot quick-change disk docking based on in-situ scanning according to claim 4 is characterized in that: The actual position of the target quick-change sub-disc (5) relative to the calibration block (8) in step 3 is calculated by the following formula: = 。 6. The method for online self-correction of robot-robot quick-change disk docking based on in-situ scanning according to claim 1 is characterized in that: The point cloud data of the target quick-change sub-disc (5) and the calibration block (8) after the slight change is recorded as , the position of the target quick-change sub-disc (5) after the change is calculated by the following formula: = ; Change vector .

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