A Dual Compensation Method and Device for the Pose Error of an Industrial Robot

Abstract

The present invention provides a dual compensation method for the pose error of an industrial robot, including: operating the joints of the industrial robot to perform independent rotational motions respectively to measure the fixed-point motion of the arc trajectory of the tracking target, and recording a plurality of actual position points; based on the zero point, fitting the motion plane and the motion curve of the rotational motion with the actual position points; obtaining the actual points of the normal projection of the actual position points on the motion curve, and obtaining the angular position error of the joint with the actual points and the theoretical position points of the rotational motion; obtaining the normal offset error of the joint with the actual position points and the motion plane; and performing dual compensation for the pose error of the industrial robot based on the angular position error and the normal offset error. By measuring the angular motion errors of the joints of the industrial robot, the present invention can make up for the defect that the kinematic parameters of the traditional industrial robot are inaccurately identified, and can further improve the motion accuracy of the industrial robot.

Description

Technical Field

[0001] The present invention belongs to the technical field of industrial robots, and particularly relates to a method and device for double compensation of the end pose error of an industrial robot. Background Technique

[0002] Industrial robots have become an important means of liberating production due to their advantages such as high production efficiency, high safety, and cost savings. Their reliable spatial motion accuracy is an important condition for ensuring efficient production. Due to factors such as manufacturing errors of industrial robot components, installation errors, and encoder measurement errors, the end pose accuracy of industrial robots is relatively low. Therefore, it is necessary to adopt high-precision and efficient methods to compensate for the pose errors of industrial robots.

[0003] Currently, for the pose error measurement and compensation of industrial robots at home and abroad, traditional kinematic parameter correction methods are mostly used. This method is based on a kinematic model to identify and correct the kinematic parameters of industrial robots (such as joint angles, link lengths, joint offsets, link twist angles, etc.) to improve the accuracy and accuracy of the motion of the industrial robot system, which plays a key role in the motion control and trajectory planning of industrial robots. However, this method attributes all factors affecting the end pose error of industrial robots (such as rotational motion errors of joint angles, deformations caused by temperature, etc.) to kinematic parameter errors, ignoring the compensation of motion errors during joint rotation, especially angular motion errors (angular position errors and tilting motion errors in two directions). The influence of this error on the end pose of industrial robots under the action of the Abbe arm cannot be ignored. Summary of the Invention

[0004] In view of the above problems, the present invention combines the traditional kinematic parameter correction method and proposes a double compensation method for the end pose error of an industrial robot based on pre-compensation of the angular motion error of joint rotation, including: placing the industrial robot in the zero position, measuring the current position of the tracking target on the industrial robot, and recording it as the zero point; operating each joint of the industrial robot to perform independent rotational motions respectively to measure the fixed-point motion of the circular arc trajectory of the tracking target, and recording a plurality of actual position points; based on the zero point, fitting the motion plane and motion curve of the rotational motion with the actual position points; obtaining the actual points of the normal projection of the actual position points on the motion curve, and obtaining the angular position error of the joint with the actual points and the theoretical position points of the rotational motion; obtaining the normal offset error of the joint with the actual position points and the motion plane; based on the angular position error and the normal offset error, compensating the rotational motion error of the joint angle. On this basis, further identify and correct the DH parameters of the industrial robot to achieve double compensation of the pose error of the industrial robot.

[0005] For any joint in the dual pose error compensation method of the industrial robot described in the present invention, operate the industrial robot to perform a rotational motion with a measurement interval of Δθ and a motion range of -Δθ·n to Δθ·n around this joint with the zero point P0 as the reference, and measure the actual position point P'. i (i = 1, 2, …, 2n); with this actual position point P' i (i = 1, 2, …, 2n), use the least squares method to fit the plane equation of the motion plane Ω1 and the spherical equation of the sphere where the motion curve is located.

[0006] In the dual pose error compensation method of the industrial robot described in the present invention, based on the plane equation and the spherical equation, obtain the spatial position coordinates of the projection of the actual position point on the theoretical curve, and combine with the spatial position coordinates of the theoretical position point on the curve to obtain the in-plane distance between the actual position point and the theoretical position point, and convert it into the angular error in the plane. Based on the in-plane angular errors of all the actual points, obtain the angular position error of each measurement point when the joint of the industrial robot rotates. Based on the data processing of the angular position error of each measurement point by the linear interpolation method, obtain the angular position error of any point within the measurement range of the joint of the industrial robot; based on the plane equation, obtain the projection distance of the actual position point relative to the motion plane, and obtain the normal offset error of each actual position point when the joint rotates. Based on the data processing of the normal offset error of each actual position point by the linear interpolation method, obtain the normal offset error of any point within the measurement range of the joint.

[0007] The present invention also proposes a dual pose error compensation device for an industrial robot, including: an initialization module for placing the industrial robot in the zero position, measuring the current position of the tracking target on the industrial robot, and recording it as the zero point; a measurement module for operating each joint of the industrial robot to perform independent rotational motions respectively to measure the fixed-point motion of the circular arc trajectory of the tracking target, and recording multiple actual position points; a fitting module for fitting the motion plane and the motion curve of the rotational motion based on the zero point and the actual position points; an error acquisition module for obtaining the actual point of the normal projection of the actual position point on the motion curve, and obtaining the angular position error of the joint with this actual point and the theoretical position point of the rotational motion; and obtaining the normal offset error of the joint with this actual position point and the motion plane; a compensation module for compensating the rotational angle motion error of the joint based on the angular position error and the normal offset error. On this basis, further identify and correct the DH parameters of the industrial robot to achieve dual pose error compensation of the industrial robot.

[0008] The dual compensation device for the pose error of the industrial robot according to the present invention, wherein the measurement module includes: for any joint, operating the industrial robot to perform a rotational motion with the zero point P0 as the reference, a measurement interval of Δθ, and a motion range of -Δθ·n to Δθ·n, and measuring to obtain the spatial position coordinates of the actual position points P' i (i = 1, 2, …, 2n); using the actual position points P' i (i = 1, 2, …, 2n), and fitting the plane equation of the motion plane Ω1 and the spherical equation of the spherical surface where the motion curve is located by using the least squares method.

[0009] The dual compensation device for the pose error of the industrial robot according to the present invention, wherein the error acquisition module includes an angular position error acquisition module and a normal offset error acquisition module. The angular position error acquisition module is used to obtain the spatial position coordinates of the projection of the actual position point on the theoretical curve based on the plane equation and the spherical equation, and combine the spatial position coordinates of the theoretical position point on the curve to obtain the in-plane distance between the actual position point and the theoretical position point, and convert it into an in-plane angular error. Based on the in-plane angular errors of all the actual points, the angular position error of each measurement point when the joint of the industrial robot rotates is obtained. Based on the data processing of the angular position error of each measurement point by using the linear interpolation method, the angular position error of any point within the measurement range of the joint of the industrial robot is obtained; the normal offset error acquisition module is used to obtain the projection distance of the actual position point relative to the motion plane based on the plane equation, obtain the normal offset error of each actual position point when the joint rotates, and based on the data processing of the normal offset error of each actual position point by using the linear interpolation method, obtain the normal offset error of any point within the measurement range of the joint.

[0010] The present invention also proposes an electronic device, including the dual compensation device for the pose error of the industrial robot as described above.

[0011] The present invention also proposes a computer-readable storage medium, storing computer-executable instructions, characterized in that when the computer-executable instructions are executed, the dual compensation method for the pose error of the industrial robot as described above is implemented.

[0012] The dual compensation method for the pose error of the industrial robot proposed by the present invention can make up for the defect of inaccurate identification of kinematic parameters of traditional industrial robots by pre-measuring and compensating the angular motion errors of each joint of the industrial robot, and can further improve the motion accuracy of the industrial robot. Description of the Drawings

[0013] Figure 1 It is a schematic diagram of the measurement process of the angular motion error of the joint of the industrial robot by a laser tracker.

[0014] Figure 2 It is the flow chart of the double compensation method for the pose error of the industrial robot of the present invention.

[0015] Figure 3 It is the flow chart for obtaining the angular position error and the normal offset error.

[0016] Figure 4 It is the schematic diagram of the geometric relationship for separating the angular motion error during the rotational motion of joint 1 of the industrial robot.

[0017] Figure 5 It is the flow chart for compensating the angular motion error.

[0018] Figure 6 It is the schematic diagram of the process for measuring and compensating the angular motion error during the rotational motion of joint 1 of the industrial robot.

[0019] Figure 7 It is the schematic diagram of the process for measuring and compensating the angular motion error during the rotational motion of joint 2 of the industrial robot.

[0020] Figure 8 It is the schematic diagram of the process for measuring and compensating the angular motion error during the rotational motion of joint 3 of the industrial robot.

[0021] Figure 9 It is the schematic diagram of the process for measuring and compensating the angular motion error during the rotational motion of joint 4 of the industrial robot.

[0022] Figure 10 It is the schematic diagram of the double compensation device for the pose error of the industrial robot of the present invention.

[0023] Figure 11 It is the schematic diagram of the error acquisition module.

[0024] Figure 12 It is the schematic diagram of an electronic device of the present invention.

[0025] Figure 13 It is the schematic diagram of the hardware structure of an electronic device of the present invention.

[0026] Among them, the reference signs are:

[0027] 1, 2, 3, 4, 5, 6: Joints

[0028] 7, 9, 10: Motion trajectories

[0029] 8: Tracking target

[0030] 11: Measuring laser;

[0031] 12: Laser tracker.

[0032] 13: Industrial robot

[0033] 14: Adapter plate

[0034] 100: Electronic device 20: Dual compensation device for pose error of industrial robot

[0035] 21: Initialization module 22: Measurement module

[0036] 23: Fitting module 24: Error acquisition module

[0037] 241: Angular position error acquisition module 242: Normal offset error acquisition module

[0038] 25: Compensation module

[0039] S1, S2, S3, S4, S41, S42, S5, S51, S52, S6: Steps Detailed implementation manners

[0040] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific implementation methods described herein are only used to explain the present invention and are not used to limit the present invention.

[0041] It should be noted that in this application, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the element.

[0042] Aiming at the defects of the prior art, the present invention provides a dual compensation method for the pose error of an industrial robot, which can further improve the pose accuracy of the end of the industrial robot on the basis of traditional kinematic parameter correction, and provides a reliable solution for the spatial pose error compensation of the industrial robot.

[0043] Figure 1 It is a schematic diagram of the measurement process of the angular motion error of the industrial robot joint by a laser tracker. As Figure 1As shown in the figure, the measuring instrument is a laser tracker 12, and the tracking target 8 of the laser tracker 12 is installed at the end of the industrial robot 13; then, the joints of the industrial robot are respectively controlled to perform single-joint rotation motion, driving the tracking target 8 to perform fixed-point motion along an arc trajectory; the laser tracker 12 records the fixed-point position coordinates of the circular trajectory, and combines the established identification model to separate the rotation angle motion error of each joint.

[0044] Figure 2 It is the flow chart of the double compensation method for the pose error of the industrial robot of the present invention. As Figure 2 shown, in the first embodiment of the present invention, a double compensation method for the pose error of an industrial robot is proposed. Taking the double compensation of the angular motion error of joint 1 as an example, the double compensation method for the pose error of the industrial robot will be specifically described below:

[0045] Step S1: Place the industrial robot 13 at the zero position, measure the current position of the tracking target 8 on the industrial robot 13 through the laser tracker 12, and record it as the zero point P0, and its spatial position coordinates are (x0, y0, z0).

[0046] Step S2: Manipulate joint 1 of the industrial robot 13 to perform an independent rotation motion along the motion trajectory 9, and the laser tracker 12 measures the fixed-point motion of the tracking target 8 along the arc trajectory, and records a plurality of actual position points P' i (i = 1, 2,..., 2n);

[0047] As Figure 3 shown, the fixed-point motion of joint 1 along the arc trajectory is a rotation motion with the zero point P0 as the reference, a measurement interval of Δθ, and a motion range of -Δθ·n to Δθ·n, and 2n actual position points P'1, P'2,..., P' i 、……、P' 2n ; among them, the spatial position coordinates of P' i (i = 1, 2,..., 2n) are (x' i , y' i , z' i );

[0048] When joint 1 is in motion and there is no motion error, the tracking target 8 at the end of the industrial robot will move along the arc trajectory 9 in the plane Ω1, and the ideal point is (P0~P 2n ); when considering the angular motion error (angular position error and tilting motion errors in two directions), under the action of the Abbe principle, the actual measurement points will deviate from the ideal points and become (P'1~P' 2n), which results in the end position error of the industrial robot. This error can be approximately divided into two parts: the error in plane Ω1 (caused by the angular position error) and the normal offset error of plane Ω1 (caused by the tilt motion error).

[0049] Step S3: Based on the zero point P0, the actual position point P' i Fitting the motion plane and motion curve of the circular trajectory fixed-point motion of joint 1; specifically including:

[0050] The actual position points should theoretically be within the spatial plane Ω1, so the least squares fitting is performed on these points to minimize the distance between all actual position points and plane Ω1, and the plane equation of plane Ω1 is obtained as follows:

[0051] a1x+b1y+c1z+d1=0

[0052] Among them, a1, b1, c1 are the elements of the plane normal vector, and d1 is the distance constant of the plane.

[0053] Since the zero point P0 (x0, y0, z0) is used as the reference point, there is no error in its position, so we can get:

[0054] c1=(-d1-a1x0-b1y0) / z0

[0055] Combine the above formulas to solve for any spatial point P' i (x' i ,y' i ,z' i ) to the distance Δ from the plane Ω1 i :

[0056]

[0057] make

[0058] According to the least squares method The smallest, you can get the plane equation parameters (a1, b1, c1, d1) of plane Ω1, and you can also get the plane normal vector

[0059] Then, the actual position point should theoretically be on the motion trajectory 9, and the spherical equation of the space sphere where it is located is:

[0060] (xO x ) 2 +(yO y ) 2 +(zO z ) 2 =R 2

[0061] Among them (Ox , O y , O z ) is the center of the spherical surface in space, and R is the radius of the spherical surface in space.

[0062] The combined motion trajectory 9 must pass through the zero point P0(x0, y0, z0). Further construct any spatial point P' i (x' i , y' i , z' i )'s constraint equation:

[0063]

[0064] At the same time, the motion trajectory 9 must be on the above-fitted plane. From this, we can obtain:

[0065] z' i = (-d1 - a1x' i - b1y' i ) / c1

[0066] Substitute z' i into the above constraint equation, and combine the least squares method to make the smallest, then the center of the sphere (O x , O y , O z ) and the radius R can be obtained.

[0067] Step S4: Obtain the actual point of the normal projection of the actual position point on the motion curve, and obtain the angular position error of joint 1 with this actual point and the theoretical position point of the rotational motion; obtain the normal offset error of joint 1 with the actual position point and the motion plane; as Figure 3 shown, it specifically includes:

[0068] Step S41: Measure the angular position error of joint 1

[0069] After obtaining the circular trajectory equation of the intersection of plane Ω1 and the spherical surface in space, the angular position error will be solved. As Figure 4 shown, taking the solution of the angular position error of points P1 and P n+1 as an example, P0, P1, P n+1 are the theoretical position points during the motion of the industrial robot. These theoretical position points should theoretically be on the circular trajectory of the intersection of plane Ω1 and the spherical surface in space. The theoretical chord lengths corresponding to the equal-interval rotation of Δθ are P0P1 and P0P n+1 . However, there are deviations between the actual position points P'1 and P' n+1 and the theoretical position points. Project the actual position points onto the fitted circular trajectory, and the projected points are Q1 and Q n+1 . At this time, the corresponding actual chord lengths are P0Q1 and P0Q n+1According to this chord length, the actual rotation angles θ1 and θ n+1 .

[0070] Then P n+1 Take the actual chord length corresponding to the point as an example. Connect O1P' n+1 , whose direction vector is Will and The cross product gives ΔO1P' n+1 Q n+1 The plane ω n+1 The normal vector This plane equation can be established:

[0071] a3(xO x )+b3(yO y )+c3(zO z )=0

[0072] Joint ω n+1 The plane equation and the circle trajectory equation can be solved for the actual point Q n+1 The corresponding coordinates are:

[0073]

[0074] Similarly, points P'1, P'2, P'3, ..., P' 2n Corresponding to the actual points Q1, Q2, Q3, ..., Q on the circular trajectory 2n All can be solved. Calculate the actual rotation angles θ1, θ2, …, θ according to the chord lengths adjacent to the actual points 2n By comparing the actual rotation angle with the theoretical rotation angle, the angular position error Δθ1, Δθ2, …, Δθ corresponding to each position is obtained. 2n As shown in the following formula, P1, P n+1 The angular position error corresponding to the point can be solved.

[0075]

[0076] Step S42: measuring the normal offset error of the rotation plane of joint 1

[0077] The normal offset error can be calculated based on the distance from the actual position point to the plane Ω1, such as Figure 4 Medium P' n+1 With P n+1 Deviation Δz1 in the Z direction. This deviation can be measured at point P' i (x' i ,y' i ,z' i ) to the plane Ω1 is expressed as:

[0078]

[0079] Step S5. Based on the angular position error and the normal offset error obtained in Step S4, perform angular motion error compensation on Joint 1; as Figure 5 shown, it specifically includes:

[0080] Step S51. Perform angular position compensation on Joint 1 based on the angular position error;

[0081] Step S52. Perform normal offset compensation on Joint 1 based on the normal offset error; including:

[0082] After solving the normal offset error, compensate it in the form of an angle. As Figure 6 shown, Joint 1 and Joint 2 are two adjacent orthogonal rotational motion axes, and their distances from the tracking target are r1 and r2 respectively. The normal offset error generated by the motion of Joint 1 in the rotation plane can be approximately transferred to Joint 2 for compensation according to the Abbe principle, and the compensation value is shown in the following formula

[0083]

[0084] where, is the rotation angle of Joint 1.

[0085] For the normal offset errors generated during the motion of Joint 2 and Joint 3, they are represented by the same method above. As Figure 7 and Figure 8 shown, these normal offset errors Δx2 and Δx3 are both approximately compensated by the rotation angle of orthogonal Joint 1, and the angles to be compensated are and where the Abbe arm L y-p0 changes with the rotation of Joint 1, and this value can be read from the industrial robot control program interface.

[0086]

[0087] are the rotation angles of Joint 2 and Joint 3.

[0088] For Joint 4, it is relatively special. When there is no angular change in Joint 4 and the tool coordinate origin is located at the center line position of the end flange, the angular position error and the plane normal offset error of Joint 4 have no influence on the end error. In this case, to identify the rotational angle motion error of Joint 4, an adapter plate 14 needs to be added to the end of the industrial robot 13. As Figure 9As shown, place the tracking target 8 of the laser tracker 12 at one end of the adapter plate 14. Rotate the joint 4, and the measurement of the angular position error and the plane normal offset error can be achieved. During the rotational movement of the joint 4, the influence caused by the plane normal offset error Δy4 can be approximately compensated by the rotational angle of the joint 5, as shown in the following formula.

[0089]

[0090] is the rotational angle of the joint 4.

[0091] For the remaining joints of the industrial robot (such as joint 5 and joint 6), during the movement process, due to the small effective Abbe arm with the end of the industrial robot, the influence of the angular error on the end can be ignored. Therefore, the errors of joint 5 and joint 6 will not be considered in the present invention.

[0092] Combining the measurement results of the rotational angle motion errors of the above joints, the linear interpolation fitting method is used to estimate and compensate the errors at any angular position. Assume that N angular positions are measured, and each position corresponds to an angular measurement error Using piecewise linear interpolation, under the condition of the following function model is fitted:

[0093]

[0094] where and are the errors corresponding to the angular positions. For any spatial point P of the industrial robot, the corresponding theoretical angles of joints 1 to 6 are When compensating for the angular position errors and the plane normal offset errors of joints 1 to 4, the actual angles of joints 1 to 6 are:

[0095]

[0096] Step S6: Compensate the above error compensation formula in the controller of the industrial robot; then use the traditional kinematic parameter identification model to identify the D-H parameters of the industrial robot and compensate and correct them in the controller. Thus, the double compensation of the end pose error of the industrial robot is achieved.

[0097] It should be noted that in various embodiments of the present invention, the magnitudes of the serial numbers of the above steps do not mean the order of execution. The order of execution of each step should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0098] The following is a system embodiment corresponding to the above method embodiment. This embodiment can be implemented in cooperation with the above embodiment. The relevant technical details mentioned in the above embodiment are still valid in this embodiment. To avoid repetition, they will not be elaborated here. Correspondingly, the relevant technical details mentioned in this embodiment can also be applied to the above embodiment.

[0099] Figure 10 It is a schematic diagram of a dual compensation device for the pose error of an industrial robot of the present invention. As Figure 10 shown, in the second embodiment of the present invention, a dual compensation device 20 for the pose error of an industrial robot is proposed, which specifically includes:

[0100] An initialization module 21, configured to place the industrial robot at the zero position, measure the current position of the tracking target on the industrial robot, and record it as the zero point;

[0101] A measurement module 22, configured to manipulate each joint of the industrial robot to perform independent rotational motions respectively, so as to measure the fixed-point motion of the arc trajectory of the tracking target, and record and obtain a plurality of actual position points;

[0102] The measurement module 22 specifically includes: for any joint, manipulate the industrial robot to perform a rotational motion with the zero point P0 as the reference, a measurement interval of Δθ, and a motion range of -Δθ·n to Δθ·n, and measure and obtain the spatial position coordinates of the actual position points P' i (i = 1, 2,..., 2n); with the actual position points P' i (i = 1, 2,..., 2n), use the least squares method to fit the plane equation of the motion plane Ω1 and the spherical equation of the spherical surface where the motion curve is located.

[0103] A fitting module 23, configured to fit the motion plane and the motion curve of the rotational motion based on the zero point and the actual position points;

[0104] An error acquisition module 24, configured to obtain the actual points of the normal projection of the actual position points on the motion curve, and obtain the angular position error of the joint with the actual points and the theoretical position points of the rotational motion; and obtain the normal offset error of the joint with the actual position points and the motion plane;

[0105] The error acquisition module 24 includes an angular position error acquisition module 241 and a normal offset error acquisition module 242, as Figure 11As shown in the figure; among them, the angular position error acquisition module 241 acquires the spatial position coordinates of the actual position point projected on the theoretical curve based on the plane equation and the spherical surface equation, combines the spatial position coordinates of the theoretical position point on the curve, acquires the in-plane distance between the actual position point and the theoretical position point, and converts it into an in-plane angular error. Based on the in-plane angular errors of all the actual points, the angular position error of each measurement point during the rotation of the joint of the industrial robot is obtained. Based on the data processing of the angular position errors of each measurement point using the linear interpolation method, the angular position error of any point within the measurement range of the joint of the industrial robot is obtained; the normal offset error acquisition module 242 is used to acquire the projection distance of the actual position point relative to the motion plane based on the plane equation, obtain the normal offset error of each actual position point during the rotation of the joint, and perform data processing on the normal offset errors of all the actual position points using the linear interpolation method to obtain the normal offset error of any point on the motion curve of the joint.

[0106] The compensation module 25 is used to perform pre-compensation for the angular motion error of the joint based on the angular position error and the normal offset error, and perform DH parameter compensation on the industrial robot.

[0107] In the third embodiment of the present invention, a computer-readable storage medium is proposed. For the industrial robot pose error dual compensation device of the present invention, when its functions are implemented in the form of software function units and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or a part of this technical solution can be embodied in the form of a software product. This computer software product is stored in a computer-readable storage medium and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. Therefore, in the third embodiment of the present invention, a computer-readable storage medium is provided for storing a computer program for an industrial robot pose error dual compensation method. It should be understood that the computer-readable storage medium in the embodiments of the present invention can be a volatile memory and / or a non-volatile memory. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of random access memory (RAM) are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct rambus random access memory (DRRAM).

[0108] Figure 12 is a schematic diagram of an electronic device of the present invention. As Figure 12As shown, in the fourth embodiment of the present invention, an electronic device 100 is proposed, which includes the industrial robot pose error double compensation device as described above. Those of ordinary skill in the art can understand that all or part of the steps in the above method can be completed by a program to instruct related hardware (such as a processor, FPGA, ASIC, etc.). All or part of the steps of the above embodiments can also be implemented using one or more integrated circuits. Correspondingly, each module in the above embodiments can be implemented in the form of hardware, for example, by an integrated circuit to implement its corresponding function, or can be implemented in the form of a software functional module, for example, by a processor executing a program / instruction stored in a memory to implement its corresponding function. The embodiments of the present invention are not limited to any specific form of combination of hardware and software.

[0109] It should be noted that the structure of the electronic device shown in the drawings of the present invention does not constitute a limitation thereto. The actual knowledge structure recognition device may include more or fewer components than shown in the drawings, or combine certain components, or have different component arrangements.

[0110] The electronic device of the present invention can be any device with data processing capabilities, and the any device with data processing capabilities can be a device or apparatus such as a computer. The device embodiment can be implemented by software, or by hardware or a combination of software and hardware. Taking software implementation as an example, as a logically meaningful device, it is formed by a processor of any device with data processing capabilities reading the corresponding computer program instructions in a non-volatile memory into the memory for operation. Figure 13 It is a schematic diagram of the hardware structure of an electronic device of the present invention. As Figure 13 shown, from the hardware level, it is a hardware structure diagram of any device with data processing capabilities where the industrial robot pose error double compensation device of the present invention is located. In addition to Figure 13 the shown processor, memory, network interface, and non-volatile memory, the any device with data processing capabilities where the device in the embodiment is located usually includes other hardware according to the actual function of the any device with data processing capabilities, which will not be elaborated here.

[0111] When implemented using software, the above embodiments may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the processes or functions described in the embodiments of the present invention are generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wire (such as infrared, wireless, microwave, etc.). The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or a data center that contains one or more collections of available media. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a DVD), or a semiconductor medium. The semiconductor medium may be a solid-state drive.

[0112] The dual compensation method for the pose error of an industrial robot proposed by the present invention can make up for the defect of inaccurate identification of kinematic parameters of traditional industrial robots by pre-measuring and compensating the motion errors of each joint angle of the industrial robot, and can further improve the motion accuracy of the industrial robot.

[0113] The above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. Those of ordinary skill in the relevant technical fields can still make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the present invention. The patent protection scope of the present invention shall be defined by the claims.

Claims

1. A dual compensation method for the pose error of an industrial robot, characterized in that, Including: Place the industrial robot at the zero position, measure the current position of the tracking target on the industrial robot, and record it as the zero point; Manipulate each joint of the industrial robot to perform independent rotational movements respectively to measure the fixed-point movement of the circular arc trajectory of the tracking target, and record multiple actual position points; Based on the zero point, fit the plane equation corresponding to the movement plane of the rotational movement and the spherical equation of the sphere where the movement curve of the rotational movement is located with the actual position points; Based on the plane equation and the spherical equation, obtain the spatial position coordinates of the actual position points projected on the theoretical curve of the fixed-point movement of the circular arc trajectory; combine with the spatial position coordinates of the theoretical position points, obtain the in-plane distance between the actual position points and the theoretical position points, convert it into the in-plane angular error in the movement plane, based on the in-plane angular errors of all the actual position points, obtain the angular position error of each actual position point when the joint rotates, perform data processing on all the angular position errors based on the linear interpolation method, and obtain the angular position error of any point on the movement curve of the joint; based on the plane equation, obtain the projection distance of the actual position points relative to the movement plane, obtain the normal offset error of each actual position point when the joint rotates, perform data processing on the normal offset errors of all the actual position points based on the linear interpolation method, and obtain the normal offset error of any point on the movement curve of the joint; Based on the angular position error of any point on the movement curve of the joint and the normal offset error of any point on the movement curve of the joint, perform pre-compensation for the angular movement error of the joint and perform DH parameter compensation for the industrial robot.

2. The dual compensation method for the pose error of an industrial robot according to claim 1, characterized in that For any joint, manipulate the industrial robot to perform a rotational movement with the zero point P0 as the reference, a measurement interval of Δθ, and a movement range of -Δθ·n to Δθ·n, measure 2n measurement points, use the measurement points as the actual position points P', and obtain the spatial position coordinates of the actual position points; Based on the actual position points, use the least squares method to fit the plane equation and the spherical equation.

3. An industrial robot pose error double compensation device, characterized in that, Including: An initialization module, which is used to place the industrial robot at the zero position, measure the current position of the tracking target on the industrial robot, and record it as the zero point; A measurement module, which is used to manipulate each joint of the industrial robot to perform independent rotational movements respectively to measure the fixed-point movement of the circular arc trajectory of the tracking target, and record multiple actual position points; A fitting module, which is used to fit the plane equation corresponding to the movement plane of the rotational movement and the spherical equation of the sphere where the movement curve of the rotational movement is located with the actual position points based on the zero point; An error acquisition module, which is used to acquire the angular position error of the joint and the normal offset error of the joint; Including, based on the plane equation and the spherical surface equation, obtaining the spatial position coordinates of the projection of the actual position point on the theoretical curve of the fixed-point motion of the circular arc trajectory; combining the spatial position coordinates of the theoretical position point, obtaining the in-plane distance between the actual position point and the theoretical position point, converting it into the in-plane angular error in the motion plane, and based on the in-plane angular errors of all the actual position points, obtaining the angular position error of each actual position point during the rotation of the joint. Performing data processing on all the angular position errors based on the linear interpolation method to obtain the angular position error of the joint at any point on the motion curve; based on the plane equation, obtaining the projection distance of the actual position point relative to the motion plane, obtaining the normal offset error of each actual position point during the rotation of the joint, and performing data processing on the normal offset errors of all the actual position points based on the linear interpolation method to obtain the normal offset error of the joint at any point on the motion curve. A compensation module, configured to perform pre-compensation of the angular motion error on the joint and perform DH parameter compensation on the industrial robot based on the angular position error of the joint at any point on the motion curve and the normal offset error of the joint at any point on the motion curve.

4. The dual compensation device for the pose error of the industrial robot according to claim 3, characterized in that The measurement module includes: for any joint, manipulating the industrial robot to perform a rotational motion with a zero point P0 as a reference, a measurement interval of Δθ, and a motion range of -Δθ·n to Δθ·n, measuring 2n measurement points, taking the measurement points as the actual position points P', and obtaining the spatial position coordinates of the actual position points. Based on the actual position points, fitting the plane equation and the spherical surface equation using the least squares method.

5. An electronic device, including the industrial robot pose error double compensation device according to claim 3 or 4.

6. A computer-readable storage medium storing computer-executable instructions, characterized in that, When the computer-executable instructions are executed, implementing the industrial robot pose error double compensation method according to claim 1 or 2.

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