A method for quickly correcting robot accuracy according to teaching points and robot

Abstract

The present invention relates to a method and a robot for quickly correcting the accuracy of a robot according to a teaching point, the method comprising: entering a teaching calibration mode after a robot is replaced, loading a robot teaching program before the robot is replaced, the teaching program storing the robot coordinates of each teaching point; selecting some teaching points as positioning points according to the teaching program, obtaining the robot coordinates of each positioning point in the teaching program and defining them as the original robot coordinates; teaching the robot to each positioning point, reacquiring the robot coordinates and defining them as new robot coordinates; calibrating the robot according to the new robot coordinates and the original robot coordinates, obtaining the robot's parameter compensation information; correcting the robot parameters according to the parameter compensation information and controlling the robot operation accordingly. The beneficial effects of the present invention are: the calibration method is simple and easy to implement, and can effectively deal with the problem of improving the relative accuracy of the robot after the robot is replaced.

Description

Technical Field

[0001] The invention relates to the field of industrial robots, and in particular to a method for quickly correcting the accuracy of a robot according to teaching points and a robot. Background Art

[0002] Industrial robots are a type of robot widely used in industrial environments. Industrial robots can traverse teaching points according to preset teaching programs to perform work according to the expected operation trajectory. The working accuracy of industrial robots is one of the important criteria for measuring their working performance.

[0003] In robots that perform actions based on teaching programs, sometimes parts or the whole of the robot are replaced, or the robot is reassembled, or the working position of the robot is changed, etc., as needed. In these cases, the robot's own parameters will change. If not calibrated in time, the accuracy of the robot's work will be affected. In order to ensure that the accuracy of the robot after the robot is replaced is not affected by the replacement action, the industry usually uses a laser tracker to recalibrate the robot, and control the robot to teach and then perform the work based on the recalibrated robot parameters. However, the laser tracker itself is expensive, costing up to millions, and is not portable, making it inconvenient to calibrate robots in multiple work sites. At the same time, the calibration process using a laser tracker is relatively complicated, affecting the convenience of using the robot.

[0004] Therefore, it is necessary to design a method and a robot that are easy to use and low in cost and can quickly correct the robot's accuracy according to the teaching points. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a method and robot that are easy to use and low-cost for quickly correcting the robot's accuracy according to teaching points, so as to address the problem that traditional methods of correcting the robot's accuracy are difficult and costly to implement when the robot is replaced.

[0006] The present invention can adopt the following technical scheme: a method for quickly correcting the accuracy of a robot according to teaching points, wherein the robot traverses the teaching points according to a preset teaching program to perform work, and defines partial replacement of the robot, partial or complete reassembly, or movement of the robot as robot replacement, and the method includes: entering a teaching calibration mode after robot replacement occurs, loading the robot teaching program before the robot replacement occurs, and the teaching program stores the robot coordinates of each teaching point; selecting some teaching points as positioning points according to the teaching program, obtaining the robot coordinates of each positioning point in the teaching program and defining them as original robot coordinates; teaching the robot to each positioning point, reacquiring the robot coordinates and defining them as new robot coordinates; calibrating the robot according to the new robot coordinates and the original robot coordinates, and obtaining the parameter compensation information of the robot; correcting the robot parameters according to the parameter compensation information and controlling the robot operation accordingly.

[0007] Furthermore, the parameter compensation information includes kinematic parameter compensation information, and correcting the robot parameters according to the parameter compensation information and controlling the robot operation accordingly includes: updating the robot kinematic model according to the parameter compensation information, and controlling the robot to operate based on the updated kinematic model.

[0008] Furthermore, the robot coordinates include the Cartesian position and joint angles of the robot, and obtaining the parameter compensation information of the robot includes obtaining the geometric parameter error of the robot.

[0009] Furthermore, the robot parameters include: robot DH parameters, robot reduction ratio and / or coupling ratio, robot installation zero position and at least part of robot tool parameters.

[0010] The present invention may also adopt the following technical scheme: a robot, used to traverse teaching points according to a preset teaching program to perform work, defining partial replacement, partial or complete reassembly, or robot movement of the robot as robot replacement, the robot comprising: a loading module, loading the robot teaching program before robot replacement, the teaching program storing the robot coordinates of each teaching point; a sampling module, selecting some teaching points as positioning points according to the teaching program, obtaining the robot coordinates of each positioning point in the teaching program and defining them as original robot coordinates; a teaching module, teaching the robot to each positioning point, reacquiring the robot coordinates and defining them as new robot coordinates; a calibration module, calibrating the robot according to the new robot coordinates and the original robot coordinate system, and obtaining the robot parameter compensation information. A compensation module, correcting the robot parameters according to the parameter compensation information and controlling the robot operation accordingly.

[0011] Furthermore, the parameter compensation information includes kinematic parameter compensation information, and the calibration module is used to update the robot kinematic model according to the parameter compensation information, and control the robot to work based on the updated kinematic model.

[0012] Furthermore, the robot coordinates include the Cartesian position and joint angles of the robot, and obtaining the parameter compensation information of the robot includes obtaining the geometric parameter error of the robot.

[0013] Furthermore, the robot parameters include: robot DH parameters, robot reduction ratio and / or coupling ratio, robot installation zero position and at least part of robot tool parameters.

[0014] Compared with the prior art, the beneficial effects of the specific implementation of the present invention are: by utilizing the teaching program before the robot is replaced to select some positioning points, utilizing the different robot coordinates at the positioning points to determine the robot's parameter compensation information and compensate the robot parameters accordingly, the problem of the robot's own parameters changing due to transportation, maintenance, etc. and requiring complex calibration is solved. This method for robot parameter compensation is easy to implement, low-cost, and improves the convenience of using the robot. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above-mentioned objectives, technical solutions and beneficial effects of the present invention can be achieved through the following drawings:

[0016] Figure 1 Schematic diagram of a method for calibrating robot accuracy according to an embodiment of the present invention

[0017] Figure 2 Schematic diagram of a method for calibrating robot accuracy according to another embodiment of the present invention

[0018] Figure 3 Schematic diagram of a method for updating a robot kinematic model according to an embodiment of the present invention

[0019] Figure 4 Module diagram of a robot according to an embodiment of the present invention DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the present invention clearer, the scheme in the embodiment of the present invention will be described clearly and completely in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention but not all of the embodiments. Based on the embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] The present invention protects a method for quickly correcting the accuracy of a robot according to teaching points, wherein the robot traverses the teaching points according to a preset teaching program to perform work, and defines partial replacement, partial or complete reassembly of the robot, or movement of the robot as robot replacement. This method is a method for correcting the accuracy of the robot when the above robot replacement occurs, and the method is used to correct the accuracy of the robot according to the teaching points according to a preset teaching program. Figure 1, the method includes: S1, entering the teaching calibration mode after the robot is replaced, loading the robot teaching program before the robot is replaced, and the teaching program stores the robot coordinates of each teaching point. The teaching program before the robot is replaced includes: the teaching program executed by the robot before the robot is replaced, for example, replacing some parts of the robot, the robot performs work according to the teaching program before the robot parts are replaced, and after the robot parts are replaced, the new robot loads the teaching program of the robot when the parts are not replaced, and the teaching program stores the robot coordinates of each teaching point before the robot is replaced; or, replacing an old robot with a new robot to perform work, after the replacement is completed, the new robot loads the teaching program of the old robot, and corrects the robot accuracy according to the method provided by this method, so that the new robot can maintain a consistent moving trajectory with the old robot, thereby improving the relative accuracy of the robot. The method includes: S2, selecting some teaching points as positioning points according to the teaching program, obtaining the robot coordinates of each positioning point in the teaching program and defining them as original robot coordinates, that is, the original robot coordinates are the robot coordinates corresponding to each positioning point in the teaching program of the robot before the robot is replaced, that is, the positioning point is a part of the teaching point of the teaching program, when selecting the positioning points, preferably, the positioning points are dispersedly distributed, so that the relative accuracy error of the robot as a whole caused by the robot replacement can be known from the robot coordinates corresponding to the positioning points dispersedly distributed at different positions; according to the aforementioned selected positioning points, for the new robot, executing S3, teaching the robot to each positioning point, relocating the robot coordinates and defining them as new robot coordinates, that is, relocating to obtain the robot coordinates of the current robot at each positioning point, and defining the robot coordinates obtained here as new robot coordinates. That is, for the robot coordinates at the positioning points, the robot coordinates at each positioning point before the robot is replaced and the robot coordinates at each positioning point after the robot is replaced are respectively obtained, wherein the original robot coordinates are obtained according to the robot teaching program before the robot is replaced, and the new robot coordinates are obtained according to teaching the robot to each positioning point and repositioning after the robot is replaced. Specifically, the robot coordinates include the Cartesian posture and joint angle of the robot. And execute S4, calibrate the robot according to the new robot coordinates and the original robot coordinates, and obtain the parameter compensation information of the robot.Specifically, the calibration method can adopt any commonly used method. The robot needs to be calibrated before use to ensure the running accuracy. In the prior art, the robot is calibrated according to the laser tracker method, which is costly and complex to implement. In this scheme, the robot coordinates of the robot teaching program positioning point and the robot coordinates re-acquired after the robot is replaced are used to obtain two sets of robot coordinates before and after the robot is replaced. The robot coordinates include information such as robot posture and joint angle. Through this information combined with the calibration processing method in the prior art, the parameter compensation information can be obtained. Further, S5 is executed to correct the robot parameters according to the parameter compensation information and control the robot operation accordingly. By obtaining the parameter compensation information, the relative error between the robot parameters before and after the robot is replaced can be obtained. By correcting each robot parameter through the parameter compensation information, the relative error between the robot parameters after the robot is replaced and the robot parameters before the robot is replaced can be reduced or even avoided, so that the relative accuracy before and after the robot is replaced is better. After the robot parameters are corrected, the running accuracy of the robot after the robot is replaced is as consistent as possible with that of the robot before the robot is replaced, so that the problem of reduced robot accuracy caused by the robot replacement can be ignored as much as possible, and the traditional complex calibration process is also avoided. It should be pointed out that in this solution, the robot is calibrated by running to different robot coordinates at the teaching point before and after the robot is replaced. The ultimate ideal effect is that the robot after the robot is replaced after calibration and compensation is consistent with the robot before the robot is replaced. The traditional method of using a laser tracker for calibration aims to improve the absolute accuracy of the robot. The robot in this solution has been calibrated based on the robot before the robot is replaced, and its absolute accuracy is guaranteed. Using the method in this solution can quickly obtain a calibrated robot with good accuracy. The method of this embodiment can avoid complex and costly calibration work on the robot. The method is easy to implement, low cost, and fast calibration.

[0022] Furthermore, robot parameters are a summary of key parameters for controlling the operation of the robot. Robot parameters are used to affect the performance, limits and other factors of the robot's operation. For example, robot parameters generally include robot degrees of freedom, workload, working accuracy, drive mode, workspace, DH parameters, reduction ratio, etc. Based on different settings of the robot parameters, the performance and accuracy of the robot will be different. For example, in this embodiment, the robot parameters mainly affect the robot's motion performance and accuracy. The robot performs work according to the settings of the robot parameters. Preferably, the robot parameters are preset parameters, such as those generally determined by the robot's software and hardware. However, the robot parameters will change under certain conditions. Therefore, correction of the robot parameters can ensure that the robot always operates in a better performance environment.

[0023] In one embodiment of the present invention, it is understandable that the robot before the robot replacement and the robot after the robot replacement are preferably the same type of robot, for example, both are six-axis robots, and the robot types before and after the robot replacement are consistent, providing a basis for ensuring a consistent movement trajectory according to the teaching program. It is understandable that when the robot is only partially replaced, the robot before the robot replacement and the robot after the robot replacement are substantially the same robot.

[0024] In the method provided by the present invention, some teaching points are selected as positioning points according to the teaching program, and the parameter compensation information is obtained by different robot coordinates at the teaching points before and after the robot is replaced to correct the robot parameters. When the positioning points are selected according to the teaching program, the teaching program itself includes multiple teaching points, and some teaching points are selected as positioning points. The number of selected positioning points is determined based on the number of parameters that the robot needs to solve. For example, in one embodiment of the present invention, the robot is a multi-joint robot. Based on the different number of robot joints and the different number of parameters that need to be solved, the number of positioning points that the robot needs to select is different. For example, when the DH parameters and reduction ratio of the robot are corrected, each joint requires at least 5 parameters, because the DH parameters themselves include 4 parameters, that is, for each additional joint, the number of positioning points required needs to be increased by 5. The different selection of the number of positioning points will also affect the content of the parameter compensation information obtained when the robot is calibrated. Preferably, the number of positioning points is not less than 5 times the number of joints of the multi-joint robot to ensure the performance of the robot in parameter compensation. Based on the above selection of the number of positioning points, the robot parameter correction requirements can be met. Optionally, the selection of positioning points can be automatically selected by the robot based on the determined total number, and the robot stores the robot coordinates of each positioning point when the robot is taught to pass through that position. Alternatively, for the selection of positioning points, the robot provides the user with options through a teach pendant, and the user can select the positioning points based on the options provided by the robot. The selection of positioning points is not a limitation of the present invention, and a variety of methods can be used to determine the positioning points while ensuring the number of positioning points.

[0025] In one embodiment, Figure 2, after obtaining the parameter compensation information, correcting the robot parameters according to the parameter compensation information and controlling the robot accordingly include: S51, updating the robot kinematic model according to the parameter compensation information, and controlling the robot to work based on the updated kinematic model. Generally speaking, the kinematic model of the robot is a preset model. In this embodiment, the kinematic model is updated by the obtained parameter compensation information. After that, the robot works based on the updated kinematic model, which can achieve the effect of compensating the robot parameters. Specifically, updating the robot kinematic model according to the parameter compensation information includes substituting the parameter compensation information into the kinematic model to obtain an updated robot kinematic model. The subsequent operation of the robot is based on the updated kinematic model, thereby ensuring the relative accuracy of the robot operation. Specifically, the parameter Figure 3 , setting the robot kinematic model to X=f(g), the parameter compensation information to Δg, and updating the robot kinematic model according to the parameter compensation information in the above S51 include: S511, substituting the parameter compensation information Δg into the kinematic model X=f(g); S512, updating the robot kinematic model X=f(g+Δg); S513, controlling the robot to work based on the updated kinematic model X=f(g+Δg). The original kinematic model of the robot is f(g), and the updated kinematic model of the robot is f(g+Δg). Based on the updated kinematic model of the robot, the robot parameters are corrected, such as the robot DH parameters, the reduction ratio, etc., so as to ensure the relative accuracy of the robot operation. For example, by correcting the various parameters of the robot, after the robot is replaced, the robot can ensure the same motion trajectory as the robot before the robot is replaced, or can ensure the same end accuracy, etc. The above processing method can reduce or even eliminate the problem of change in robot accuracy caused by robot replacement, so that the relative accuracy of the robot before and after the robot replacement is better. For the operation of the robot, the impact of robot replacement on the robot's execution of work can be almost ignored. In another embodiment of the present invention, the robot includes joints and connecting rods, the robot end is connected to a tool to perform work, and the robot parameters include: robot DH parameters, robot reduction ratio and / or coupling ratio, robot installation zero position, robot tool parameters, at least one, the robot compensates at least part of the above robot parameters through parameter compensation information to reduce or even eliminate the robot error before and after the replacement caused by the robot replacement, so that the accuracy of the robot after the robot replacement is guaranteed and can be consistent with the performance before the robot replacement.

[0026] Based on the correction of the robot parameters, the robot after robot replacement can maintain relatively consistent accuracy with that before robot replacement, and the robot can automatically correct errors that may exist due to robot replacement based on the updated robot parameters in subsequent work. For example, when the robot is re-taught, or when the robot performs tasks such as disordered grasping that does not require teaching, the performance of the robot operation can also be guaranteed based on the latest information acquired in combination with the corrected robot parameters.

[0027] The beneficial effect of the above preferred embodiments is: in the event that the robot replacement occurs and causes the robot parameters to shift, the positioning points are selected according to the teaching points based on the teaching program, and the different robot coordinates at the same position before and after the robot replacement are calculated to obtain parameter compensation information and compensate the robot parameters accordingly, so that after the robot is replaced, the relative error of the robot caused by the replacement behavior can be known and automatically compensated, avoiding a complicated calibration process. The method is easy to implement, low-cost, and improves the convenience of using the robot.

[0028] The present invention also protects a robot for traversing teaching points according to a preset teaching program to perform work, defining partial replacement of the robot, partial or complete reassembly of the robot, or movement of the robot as robot replacement, Figure 4 The robot 100 includes: a loading module 10, which loads the robot teaching program before the robot is replaced, and the teaching program stores the robot coordinates of each teaching point; a sampling module 20, which selects some teaching points as positioning points according to the teaching program, obtains the coordinates of each positioning point in the teaching program and defines them as the original robot coordinates; a teaching module 30, which teaches the robot to each positioning point, re-acquires the robot coordinates and defines them as new robot coordinates; a calibration module 40, which obtains the robot's parameter compensation information according to the difference between the original robot coordinates and the new robot coordinates; a compensation module 50: corrects the robot parameters according to the parameter compensation information and controls the robot operation accordingly. The work content performed by the above modules is consistent with the content of the various methods described above, and will not be repeated here.

[0029] In one embodiment of the present invention, the calibration module is used to update the robot kinematics model according to the parameter compensation information, and control the robot to work based on the updated kinematics model. The specific implementation content is consistent with the above, and will not be repeated here.

[0030] Furthermore, the robot coordinates include information such as the Cartesian position and posture of the robot, joint angles, etc., and obtaining the parameter compensation information of the robot includes obtaining the geometric parameter error of the robot.

[0031] In one embodiment of the present invention, the robot is a multi-joint robot, the number of joints of the robot determines the degree of freedom of the robot, and the number of positioning points selected by the sampling module 20 is not less than 5 times the number of joints of the multi-joint robot, so that parameter compensation information can be obtained according to the robot coordinate difference at the positioning point before and after the robot is replaced. Specifically, the robot includes joints and connecting rods, the robot end is connected to a tool to perform work, and the robot parameters include at least one of the robot DH parameters, the robot reduction ratio and / or coupling ratio, the robot installation zero position and the robot tool parameters. By compensating at least part of the above robot parameters, the relative accuracy of the robot before and after the robot is replaced is better, and can be basically consistent with the robot before the robot is replaced, avoiding the accuracy of the robot's work being affected by the robot replacement.

[0032] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for quickly correcting the accuracy of a robot according to a teaching point, wherein the robot traverses the teaching point according to a preset teaching program to perform work, and the partial replacement, partial or complete reassembly of the robot, or the movement of the robot is defined as robot replacement, characterized in that: The method comprises: Entering the teaching calibration mode after the robot is replaced, loading the robot teaching program before the robot is replaced, wherein the teaching program stores the robot coordinates of each teaching point; Selecting some teaching points as positioning points according to the teaching program, obtaining the robot coordinates of each positioning point in the teaching program and defining them as original robot coordinates; Teach the robot to each positioning point, reacquire the robot coordinates and define them as new robot coordinates; Calibrate the robot according to the new robot coordinates and the original robot coordinates to obtain parameter compensation information of the robot; Correcting the robot parameters according to the parameter compensation information and controlling the robot operation accordingly; the parameter compensation information includes kinematic parameter compensation information, and correcting the robot parameters according to the parameter compensation information and controlling the robot operation accordingly include: updating the robot kinematics model according to the parameter compensation information, and controlling the robot to work based on the updated kinematics model; The robot coordinates include the Cartesian position and joint angles of the robot, and obtaining the parameter compensation information of the robot includes obtaining the geometric parameter error of the robot.

2. The method according to claim 1, characterized in that The robot parameters include: robot DH parameters, robot reduction ratio and / or coupling ratio, robot installation zero position and robot tool parameters at least in part.

3. A robot, used to traverse teaching points according to a preset teaching program to perform work, defining partial replacement of the robot, partial or complete reassembly, or movement of the robot as robot replacement, characterized in that: The robot comprises: A loading module is used to load the robot teaching program before the robot is replaced, wherein the teaching program stores the robot coordinates of each teaching point; A sampling module selects some teaching points as positioning points according to the teaching program, obtains the robot coordinates of each positioning point in the teaching program and defines them as original robot coordinates; Teaching module, teaching the robot to each positioning point, re-obtaining the robot coordinates and defining them as new robot coordinates; A calibration module is used to calibrate the robot according to the new robot coordinates and the original robot coordinate system to obtain parameter compensation information of the robot; A compensation module, which corrects the robot parameters according to the parameter compensation information and controls the operation of the robot accordingly; The parameter compensation information includes kinematic parameter compensation information, and the calibration module is used to update the robot kinematic model according to the parameter compensation information, and control the robot to work based on the updated kinematic model; The robot coordinates include the Cartesian position and joint angles of the robot, and obtaining the parameter compensation information of the robot includes obtaining the geometric parameter error of the robot.

4. The robot according to claim 3, characterized in that: The robot parameters include: robot DH parameters, robot reduction ratio and / or coupling ratio, robot installation zero position and robot tool parameters at least in part.

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