Quick intelligent teaching system and teaching method for robot quick-change disc based on scanning measurement

Abstract

The invention discloses a robot quick-change disc rapid intelligent teaching system and teaching method based on scanning measurement, and belongs to the field of robot quick-change disc automatic teaching systems. The linkage laser scanning module is arranged on the mother disc, precision measurement of the disc face and characteristics of the son disc is achieved, accurate disc face butt joint characteristic geometrical morphology and position information are constructed through measured target disc face point clouds, target disc face geometrical characteristics under different postures are determined in combination with an interactive intelligent characteristic recognition algorithm, and the accuracy of the disc face butt joint characteristic is improved. And precise butt joint of the robot R-side mother disc and the work station T-side son disc is completed in a self-adaptive mode. The robot track can be reasonably planned, the robot locating precision is guaranteed, the problems that manual teaching is low in efficiency, unstable in precision and prone to abrasion are solved, the butt joint precision and stability of an end effector are improved, and abrasion loss is reduced.

Description

Technical Field

[0001] The invention relates to an automatic teaching system for a robot quick-change disk, and in particular to a rapid intelligent teaching system and a teaching method for a robot quick-change disk based on scanning measurement. Background Art

[0002] As a key part for switching tools in automated production lines of multi-variety mixed-line production lines, quick-change disks are widely used in multi-task switching of welding guns and welding fixtures at welding gun stations in automobile welding production lines. Usually, the workstation robot equipped at the station is used as the motion actuator. The terminal quick-change disk consists of two parts, the mother and child disks (R side and T side), which respectively include a mechanical docking locking mechanism and an electrical hydraulic interface. The mother disk (R side) is a common part, which is connected to the robot's terminal flange; the child disk (T side) is a working part, corresponding to multi-task tooling fixtures, welding guns, tightening guns and other actuators; when working, the workstation robot drives the quick-change disk mother disk to dock with the child disk equipped with each task working part, and the mother and child disk connection is initially positioned through mechanical docking through the hole pins of the quick-change mother disk and the child disk, and then a reliable connection is achieved through the locking mechanism, thereby ensuring the precise matching of the electrical interface and realizing the electrical connection of the working parts. The key is how to quickly plan the running trajectory of the multi-task workstation robot and complete the precise docking of the mother and child disks at both ends of the R and T sides of the robot, thereby ensuring the docking accuracy of the quick-change mother and child disks during multi-task switching, so as to reduce the extrusion, collision and even docking failure caused by the floating positioning deviation of the working part on the parking station during the multi-task switching process.

[0003] At present, robot teaching in automobile welding production lines still relies on handheld teaching mode assisted by manual on-site visual assistance. The teaching time is long and the workload is heavy. Moreover, due to the use of visual teaching methods, the teaching trajectory accuracy is low. In addition, due to the influence of uncertain factors such as human and environmental factors, the consistency of the docking accuracy of different teaching is poor. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a robot quick-change disc fast intelligent teaching system and teaching method based on scanning measurement.

[0005] To achieve the above-mentioned purpose of the invention, the present invention provides a robot quick-change disk fast intelligent teaching system based on scanning measurement, characterized in that it includes a workstation robot module, a workstation parking rack arranged on one side of the workstation robot module, and a central ECU end; the workstation robot module includes a first controller and a mechanical arm, a flange is provided at the end of the mechanical arm, a quick-change disk master and a laser scanning module are connected to the flange, and the laser scanning module includes a second controller and a laser scanning probe; the workstation parking rack includes a parking bracket, and the parking bracket is provided with a plurality of working end execution components with quick-change disks facing the side of the workstation robot; the central ECU end is respectively connected to the first controller and the second controller to respectively realize the control of the workstation robot module and the laser scanning module.

[0006] Preferably, a calibration block is fixed on the parking bracket near the working end execution component, and the calibration block is used to calibrate the measurement point cloud of the quick-change plate.

[0007] Preferably, the working end execution component is connected to the quick-change plate plate through a fixture, and the fixture is parked on a station bracket to achieve positioning and storage of the working end execution component.

[0008] Preferably, the quick-change plate master is provided with guide pins, and the quick-change plate master is provided with corresponding guide holes.

[0009] Preferably, the central ECU terminal includes a host computer system and a human-computer interaction interface.

[0010] The present invention also provides a teaching method of a robot quick-change plate fast intelligent teaching system based on scanning measurement, which is characterized by comprising the following steps:

[0011] Step 1: Convert the measured point cloud including the calibration block and the surface of the quick-change plate obtained by scanning the laser scanning module into a point cloud expressed in the robot working coordinate system, so as to serve as the reference coordinate system for the docking trajectory planning of the quick-change plate mother plate and the daughter plate;

[0012] Step 2: Obtain the local coordinate system conversion matrix through the calculation of the calibration block point cloud and the quick-change plate surface point cloud, and then combine the transformation matrix from the measured point cloud to the robot working coordinate system to transform the measured quick-change plate point cloud origin to the posture expressed in the robot working coordinate system, and transform the measured quick-change plate point cloud to obtain the actual deflection matrix of the motion trajectory of the quick-change plate and the mother plate relative to the theoretical calibration block, thereby determining the quick-change plate docking feature vector and position information expressed in the robot working coordinate system;

[0013] Step three, plan the quick-changer plate docking trajectory, take the converted calibration block measurement point cloud as the benchmark, calculate the motion trajectory of the quick-changer plate center relative to the measured quick-changer plate corresponding to the docking feature, and generate the corresponding robot control program on the central ECU end, and then control the workstation robot to complete the docking action of the quick-changer plate and the master plate.

[0014] Preferably, the process of obtaining the measurement point cloud including the calibration block and the quick-change plate surface by scanning with the laser scanning module comprises the following sub-steps:

[0015] Before measurement: first, park the working end actuator to be taken on the parking bracket of the workstation parking rack, and adjust the calibration block so that the quick-change plate tray connected to the working end actuator is in the same field of view measured by the laser scanning probe; then, take the quick-change plate tray guide hole position and the laser scanning probe measurement field as the reference, and design the scanning measurement path based on this initial positioning relationship; design the scanning strategy, and design the starting and ending points of the scanning trajectory based on the calibration block and the end quick-change plate tray being in the same measurement data;

[0016] Measurement execution: During the measurement, the workstation robot and the laser scanning probe are linked to each other for scanning measurement. First, the workstation robot drives the laser scanning probe to move to the measurement starting point, and the central ECU communicates with the second controller to control the start of the laser scanning probe data transmission; then the workstation robot drives the laser scanning probe to complete the scanning measurement of the quick-change plate at a constant speed, thereby obtaining a point cloud data set containing the calibration block and the surface of the quick-change plate. 0～l ,{B 子盘} 0～l}.

[0017] Preferably, the step 1 specifically includes: designing a standard calibration block CAD model expressed in a working coordinate system, and generating a point cloud {{Q0} extracted from the standard calibration block CAD model 0～l}; Then, the measured calibration block point cloud {{B0} 0～l} and point cloud extracted from CAD model{{Q0} 0～l} to match the point cloud and obtain the transformation matrix T from the CAD model to the measured point cloud 测→CAD , that is, the transformation matrix from the measured point cloud to the robot working coordinate system. Thus, the point cloud data measured by the laser scanning probe is converted into a point cloud expressed in the robot working coordinate system, denoted as {{B0} 0～l ,{B 子盘} 0～l} CAD =T 测→CAD {{B0} 0～l ,{B 子盘} 0～l}.

[0018] Preferably, the acquisition of the local coordinate system transformation matrix in step 2 includes the following sub-steps:

[0019] The position information of the surface positioning features of the quick-change plate is extracted by locating the calibration block point cloud. First, the calibration block point cloud is selected through the human-computer interaction interface of the host computer system on the central ECU side. 0～l}, extract its surface positioning features and coordinate origin; then, through the human-computer interaction interface of the host computer system on the central ECU side, select the surface point cloud of the quick-change plate {{B 子盘} 0～l}, respectively extract the surface feature normal vector and the coordinate information of the sub-disk guide hole feature; calibrate the block point cloud {{B0} 0～l} and the surface point cloud of the quick-change plate {{B 子盘} 0～l} Relative position calculation, and then obtain the local coordinate system transformation matrix of the two, denoted as t 0→子盘 .

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention proposes a robot quick-change plate fast intelligent teaching system based on scanning measurement. By integrating the laser scanning in-situ measurement on the robot end master plate, the positioning feature information of the quick-change plate plate at the working end of the parking station can be identified, and the end surface normal vector of the target matching feature and the position information of the positioning hole feature can be accurately extracted, avoiding the inaccurate positioning docking of manual visual teaching, and effectively improving the accuracy and reliability of the quick-change plate master plate docking;

[0022] 2. The present invention proposes to identify the position of the quick-changer plate at the working end to be docked through a calibration block, which solves the influence of the robot's movement accuracy during the hand-eye calibration process and can effectively improve the docking accuracy of the terminal quick-changer plate. By identifying the position of the terminal quick-changer plate, the robot docking trajectory and the corresponding execution program are automatically generated, which can greatly improve the efficiency of manual teaching on the basis of improving the quick-changer plate docking accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the robot quick-change disc fast intelligent teaching system based on scanning measurement of the present invention.

[0024] Figure 2 for Figure 1 Enlarged view of point A in .

[0025] Figure 3 for Figure 1 Enlarged view of point B in .

[0026] Figure 4The present invention is a schematic flow chart of the teaching method of the robot quick-change disc fast intelligent teaching system based on scanning measurement.

[0027] In the figure: 1 is the workstation robot module, 2 is the flange, 3 is the first controller, 4 is the quick-change disk master, 5 is the quick-change disk plate, 6 is the working end execution component, 7 is the tooling fixture, 8 is the parking bracket, 9 is the calibration block, 10 is the guide pin, 11 is the guide hole, 12 is the laser scanning module, and 13 is the central ECU end. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0029] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on this patent; in order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0030] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "inner", "outer", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0031] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0032] See also Figure 1-3As shown, the technical solution proposes a robot quick-change disc fast intelligent teaching system based on scanning measurement, including a workstation robot module, a workstation parking rack arranged on one side of the workstation robot module, and a central ECU terminal.

[0033] Specifically, the workstation robot module includes a first controller and a mechanical arm, a flange is provided at the end of the mechanical arm, a quick-change disk master and a laser scanning module are connected to the flange, and the laser scanning module includes a second controller and a laser scanning probe. A guide pin is provided on the quick-change disk master.

[0034] The workstation parking rack includes a parking bracket, and a plurality of working end execution components with quick-change plate trays are placed on the parking bracket facing the workstation robot. The working end execution components are connected to the quick-change plate tray through a fixture, and the fixture is placed on the station bracket to realize the positioning and storage of the working end execution components; the quick-change plate tray is provided with guide holes corresponding to the guide pins on the quick-change plate mother plate. A calibration block is also fixed on the parking bracket near the working end execution component, and the calibration block is used to calibrate the measurement point cloud of the quick-change plate tray. It should be noted that the working end execution component can be a fixture, welding gun, tightening gun and other tools to correspond to multi-tasking processing.

[0035] The central ECU is connected to the first controller and the second controller respectively to control the workstation robot module and the laser scanning module respectively. The central ECU includes a host computer system and a human-computer interaction interface. The host computer system is used to generate and output control instructions; the human-computer interaction interface is used for the operator to input control instructions, set parameters, etc.

[0036] refer to Figure 4 The present invention also provides a teaching method of a robot quick-change plate fast intelligent teaching system based on scanning measurement, comprising the following steps:

[0037] Step 1: Convert the measured point cloud including the calibration block and the quick-change plate surface obtained by the laser scanning module into a point cloud expressed in the robot working coordinate system, which serves as the reference coordinate system for the quick-change plate mother plate and child plate docking trajectory planning. The specific process of this step is as follows:

[0038] Before measurement: first, park the working end actuator to be taken on the parking bracket of the workstation parking rack, and adjust the calibration block so that the quick-change plate tray connected to the working end actuator is in the same field of view measured by the laser scanning probe; then, take the quick-change plate tray guide hole position and the laser scanning probe measurement field as the reference, and design the scanning measurement path based on this initial positioning relationship; design the scanning strategy, and design the starting and ending points of the scanning trajectory based on the calibration block and the end quick-change plate tray being in the same measurement data;

[0039] Measurement execution: During the measurement, the workstation robot and the laser scanning probe are linked to each other for scanning measurement. First, the workstation robot drives the laser scanning probe to move to the measurement starting point, and the central ECU communicates with the second controller to control the start of the laser scanning probe data transmission; then the workstation robot drives the laser scanning probe to complete the scanning measurement of the quick-change plate at a constant speed, thereby obtaining a point cloud data set containing the calibration block and the surface of the quick-change plate. 0～l ,{B 子盘} 0～l}.

[0040] Transform the measured point cloud coordinate system into the workstation robot working coordinate system: Design a standard calibration block CAD model expressed in the working coordinate system, and generate a point cloud extracted from the standard calibration block CAD model {{Q0} 0～l}; Then, the measured calibration block point cloud {{B0} 0～l} and point cloud extracted from CAD model{{Q0} 0～l} to match the point cloud and obtain the transformation matrix T from the CAD model to the measured point cloud 测→CAD , that is, the transformation matrix from the measured point cloud to the robot working coordinate system. Thus, the point cloud data measured by the laser scanning probe is converted into a point cloud expressed in the robot working coordinate system, denoted as {{B0} 0～l ,{B 子盘} 0～l} CAD =T 测→CAD {{B0} 0～l ,{B 子盘} 0～l}.

[0041] Step 2: Obtain the local coordinate system transformation matrix through the calibration block point cloud and the quick-change plate surface point cloud computing. The process is as follows: Extract the position information of the quick-change plate surface positioning features through the calibration block positioning point cloud. First, select the calibration block point cloud {{B0} 0～l}, extract its surface positioning features and coordinate origin; then, through the human-computer interaction interface of the host computer system on the central ECU side, select the surface point cloud of the quick-change plate {{B 子盘} 0～l}, respectively extract the surface feature normal vector and the coordinate information of the sub-disk guide hole feature; calibrate the block point cloud {{B0} 0～l} and the surface point cloud of the quick-change plate {{B 子盘} 0～l} Relative position calculation, and then obtain the local coordinate system transformation matrix of the two, denoted as t 0→子盘 Then, the transformation matrix (i.e., the transformation matrix T 测→CAD), transform the measured quick-change plate point cloud origin to the position expressed in the robot working coordinate system {{B 子盘_0} 0～l} CAD =t 0→子盘 {{B0} 0～l} CAD =t 0→子盘 T 测→CAD {{B0} 0～l}, and by transforming the measured quick-change plate point cloud, the actual deflection matrix of the motion trajectory of the quick-change plate and the mother plate relative to the theoretical calibration block is obtained, thereby determining the quick-change plate docking feature vector and position information expressed by the robot working coordinate system.

[0042] Step 3: Plan the quick-change plate docking trajectory. Based on the converted calibration block measurement point cloud, calculate the motion trajectory of the quick-change plate center relative to the measured quick-change plate corresponding to the docking feature {{B 子盘_0} 0～l} CAD The host computer system on the central ECU generates the corresponding robot control program, and then controls the workstation robot to complete the docking action of the quick-change plate master.

[0043] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A robot quick-change plate fast intelligent teaching system based on scanning measurement, characterized in that: It includes a workstation robot module, a workstation parking rack arranged on one side of the workstation robot module, and a central ECU end; the workstation robot module includes a first controller and a mechanical arm, a flange is provided at the end of the mechanical arm, a quick-change disk master and a laser scanning module are connected to the flange, and the laser scanning module includes a second controller and a laser scanning probe; the workstation parking rack includes a parking bracket, and the parking bracket is provided with a plurality of working end execution components with quick-change disks facing the side of the workstation robot; the central ECU end is respectively connected to the first controller and the second controller to respectively realize the control of the workstation robot module and the laser scanning module.

2. According to the scanning measurement-based robot quick-change plate fast intelligent teaching system of claim 1, it is characterized in that: A calibration block is also fixed on the parking bracket near the working end execution component, and the calibration block is used to calibrate the measurement point cloud of the quick-change plate tray.

3. A robot quick-change plate fast intelligent teaching system based on scanning measurement according to claim 1 or 2, characterized in that: The working end execution component is connected to the quick-change plate plate through a fixture, and the fixture is parked on a station bracket to achieve positioning and storage of the working end execution component.

4. A robot quick-change plate fast intelligent teaching system based on scanning measurement according to claim 1 or 2, characterized in that: The quick-change plate master plate is provided with guide pins, and the quick-change plate master plate is provided with corresponding guide holes.

5. The robot quick-change plate fast intelligent teaching system based on scanning measurement according to claim 1 or 2, characterized in that: The central ECU terminal includes a host computer system and a human-computer interaction interface.

6. A teaching method for a robot quick-change plate fast intelligent teaching system based on scanning measurement, characterized in that: The following steps are involved: Step 1: Convert the measured point cloud including the calibration block and the surface of the quick-change plate obtained by scanning the laser scanning module into a point cloud expressed in the robot working coordinate system, so as to serve as the reference coordinate system for the docking trajectory planning of the quick-change plate mother plate and the daughter plate; Step 2: Obtain the local coordinate system conversion matrix through the calculation of the calibration block point cloud and the quick-change plate surface point cloud, and then combine the transformation matrix from the measured point cloud to the robot working coordinate system to transform the measured quick-change plate point cloud origin to the posture expressed in the robot working coordinate system, and transform the measured quick-change plate point cloud to obtain the actual deflection matrix of the motion trajectory of the quick-change plate and the mother plate relative to the theoretical calibration block, thereby determining the quick-change plate docking feature vector and position information expressed in the robot working coordinate system; Step three, plan the quick-changer plate docking trajectory, take the converted calibration block measurement point cloud as the benchmark, calculate the motion trajectory of the quick-changer plate center relative to the measured quick-changer plate corresponding to the docking feature, and generate the corresponding robot control program on the central ECU end, and then control the workstation robot to complete the docking action of the quick-changer plate and the master plate.

7. The teaching method of the robot quick-change plate fast intelligent teaching system based on scanning measurement according to claim 6 is characterized in that: The process of obtaining the measurement point cloud including the calibration block and the quick-change plate surface by the laser scanning module includes the following sub-steps: Before measurement: First, park the working end actuator to be taken on the parking bracket of the workstation parking rack, and adjust the calibration block so that the quick-change plate tray connected to the working end actuator is in the same field of view measured by the laser scanning probe; then, take the quick-change plate tray guide hole position and the laser scanning probe measurement field as the reference, and design the scanning measurement path based on this initial positioning relationship; Scanning strategy design, with the calibration block and the end quick-change plate at the same measurement data to design the starting and ending points of the scanning trajectory; Measurement execution: During the measurement, the workstation robot and the laser scanning probe are linked to each other for scanning measurement. First, the workstation robot drives the laser scanning probe to move to the measurement starting point, and the central ECU communicates with the second controller to control the start of the laser scanning probe data transmission; then the workstation robot drives the laser scanning probe to complete the scanning measurement of the quick-change plate at a constant speed, thereby obtaining a point cloud data set containing the calibration block and the surface of the quick-change plate. 0～l ,{B 子盘 } 0～l }.

8. The teaching method of the robot quick-change plate fast intelligent teaching system based on scanning measurement according to claim 7 is characterized in that: The step 1 specifically includes: designing a standard calibration block CAD model expressed in a working coordinate system, and generating a point cloud {{Q0} extracted from the standard calibration block CAD model 0～l }; Then, the measured calibration block point cloud {{B0} 0～l } and point cloud extracted from CAD model{{Q0} 0～l } to match the point cloud and obtain the transformation matrix T from the CAD model to the measured point cloud 测→CAD , that is, the transformation matrix from the measured point cloud to the robot working coordinate system. Thus, the point cloud data measured by the laser scanning probe is converted into a point cloud expressed in the robot working coordinate system, denoted as {{B0} 0～l ,{B 子盘 } 0～l } CAD =T 测→CAD {{B0} 0～l ,{B 子盘 } 0～l }.

9. The teaching method of the robot quick-change plate fast intelligent teaching system based on scanning measurement according to claim 7 or 8, characterized in that: The acquisition of the local coordinate system conversion matrix in step 2 includes the following sub-steps: The position information of the surface positioning features of the quick-change plate is extracted by locating the calibration block point cloud. First, through the human-computer interaction interface of the host computer system on the central ECU side, the calibration block point cloud is selected. 0～l }, extract its surface positioning features and coordinate origin; then, through the human-computer interaction interface of the host computer system on the central ECU side, select the surface point cloud of the quick-change plate {{B 子盘 } 0～l }, respectively extract the surface feature normal vector and the coordinate information of the sub-disk guide hole feature; calibrate the block point cloud {{B0} 0～l } and the surface point cloud of the quick-change plate {{B 子盘 } 0～l } Relative position calculation, and then obtain the local coordinate system transformation matrix of the two, denoted as t 0→子盘 .

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