SCARA robot precision detection device and precision detection compensation method

Abstract

The invention discloses an SCARA robot precision detection device and a precision detection compensation method, and the device comprises a horizontal translation mechanism which comprises an X-axis translation assembly and a Y-axis translation assembly, and the X-axis translation assembly and the Y-axis translation assembly are horizontal and are perpendicular to each other; the longitudinal release mechanism is located on the horizontal translation mechanism, the longitudinal release mechanism is provided with a shaft sleeve combined structure, the shaft sleeve combined structure can be movably assembled with a robot tail end shaft of the SCARA robot, and the robot tail end shaft has the mechanical freedom degree of linearly lifting along the Z axis and rotating around the Z axis in the shaft sleeve combined structure; the grating measuring mechanism comprises an X-axis grating assembly and a Y-axis grating assembly which are parallel to the X-axis translation assembly and the Y-axis translation assembly respectively, and the grating measuring mechanism can detect respective readings of the longitudinal release mechanism on the horizontal plane along the X axis and the Y axis. According to the invention, a follow-up measurement scheme is provided, and the plane positioning precision of the SCARA robot can be detected and improved.

Description

Technical Field

[0001] The present invention relates to the field of robot technology, and in particular to a SCARA robot precision detection device and a precision detection compensation method. Background Art

[0002] SCARA robots are an important branch of industrial robots. As the industrial robot market continues to grow, its application scenarios in the field of high-precision technology have increased significantly, and the requirements for the positioning accuracy of SCARA robots have become increasingly stringent. Therefore, it is particularly important to perform positioning accuracy detection and error compensation on SCARA robots before they go offline.

[0003] The traditional high-precision detection methods currently known to the inventors in the field of robots include laser trackers and three-coordinate measuring machines. Although the laser tracker can detect the accuracy of the robot, its high price increases the cost burden of the enterprise, and the measurement accuracy is often not as high as that of the three-coordinate measuring machine. Although the three-coordinate measuring machine has high accuracy, its measurement space is limited, it occupies a large space, is complex to operate, and requires high professional skills. In addition, since the above two measurement methods cannot communicate with the robot's control system in real time, the process from deriving the test results to calculating the compensation amount until the compensation to the control system needs to be completed manually. In particular, error compensation involves the modification of key parameters of the system, and manual operations greatly increase quality risks and reduce production efficiency. The above two methods have shortcomings in detection efficiency or compensation effect, which often make them unable to adapt to the production rhythm requirements of the production line. Summary of the invention

[0004] The problem to be solved by the present invention is to provide a SCARA robot precision detection device and a precision detection compensation method, and provide a follow-up measurement solution to detect the plane positioning accuracy of the SCARA robot.

[0005] In order to solve the above problems, the present invention provides a SCARA robot precision detection device and a precision detection compensation method. In order to achieve the above objects, the technical solution adopted by the present invention to solve the technical problems is:

[0006] A SCARA robot precision detection device comprises: a horizontal translation mechanism, comprising an X-axis translation component and a Y-axis translation component which are horizontal and perpendicular to each other; a longitudinal release mechanism, located on the horizontal translation mechanism, the longitudinal release mechanism having a shaft sleeve combination structure, the shaft sleeve combination structure being able to be movably assembled with a robot end shaft of the SCARA robot, the robot end shaft having mechanical degrees of freedom of linear lifting along a Z axis and rotating around the Z axis in the shaft sleeve combination structure; a grating measurement mechanism, comprising an X-axis grating component and a Y-axis grating component which are respectively arranged in parallel with the X-axis translation component and the Y-axis translation component, the grating measurement mechanism being able to detect respective readings of the longitudinal release mechanism along the X-axis and the Y-axis on a horizontal plane.

[0007] The beneficial effects of adopting the above technical solution are: this technical solution uses a horizontal translation mechanism and a longitudinal release mechanism, adopts a follow-up measurement solution, and proposes a detection device for the plane positioning accuracy detection needs of the SCARA robot. The longitudinal release mechanism can release the lifting and rotation constraints of the robot end axis of the SCARA robot along the plumb direction, allowing the SCARA robot to have a translation error along the plane normal and a rotation error around the plane normal. The shaft sleeve combination structure can flexibly move with the robot end and accurately detect the robot's in-plane positioning error in real time.

[0008] This technical solution detects the positioning accuracy of the SCARA robot in the horizontal plane, that is, it only detects the movement accuracy in the X and Y directions. However, considering that the SCARA robot is a four-degree-of-freedom multi-joint robot, it can also move up and down in the Z axis and rotate the robot's end axis. Therefore, the detection platform does not detect the rotation accuracy of the Z axis direction and the robot's end axis, but in order to meet the detection needs, it is necessary to release these two mechanical degrees of freedom to avoid interference and damage to the horizontal translation mechanism and grating measurement mechanism.

[0009] The equipment is easy to operate, has high measurement accuracy, low cost, and can be directly applied on the production line to meet the manufacturer's needs for on-site detection of SCARA robot positioning accuracy and rapid error compensation. The SCARA robot can be detected and adjusted through this application equipment, which can more effectively ensure the accuracy of each SCARA robot, improve product quality, and reduce detection costs.

[0010] As a further improvement of the present invention, a platform is fixed below the horizontal translation mechanism, a bracket is arranged below the platform, the bracket has a plurality of height adjustment rods, and the height adjustment rods can adjust the angle between the top surface of the platform itself and the horizontal plane.

[0011] The beneficial effect of adopting the above technical solution is that the platform and the bracket provide a reasonable height and a precise horizontal plane for the horizontal translation mechanism and the longitudinal release mechanism. The platform can be fine-tuned to a more horizontal state.

[0012] As a further improvement of the present invention, the Y-axis translation assembly includes at least two mutually parallel Y-axis guide bars, the X-axis translation assembly includes a connecting bridge, an X-axis guide bar is arranged on the top of the connecting bridge, the connecting bridge and the Y-axis guide bar are movably assembled through a slider, the X-axis guide bar is movably assembled with an X-axis slider seat, and the top of the X-axis slider seat is assembled with the shaft sleeve combination structure.

[0013] The beneficial effect of adopting the above technical solution is: using the guide rail and the slider to provide and ensure two linear translations in the horizontal plane.

[0014] As a further improvement of the present invention, the X-axis grating assembly includes an X-axis scale grating and an X-axis grating reading head, the X-axis scale grating is fixed to the side elevation of the outer wall of the connecting bridge, and the X-axis grating reading head is fixed to one side of the X-axis slider seat and extends downward; the Y-axis grating assembly includes a Y-axis scale grating and a Y-axis grating reading head, the Y-axis scale grating is fixed to the surface of the platform, and the Y-axis grating reading head is fixed to one end of the connecting bridge and extends downward.

[0015] The beneficial effect of adopting the above technical solution is that the actions performed by the robot's terminal axis can read the displacement of the SCARA robot's terminal on the XY plane through the Y-axis grating reading head and the X-axis grating reading head. The Y-axis grating reading head and the X-axis grating reading head are connected to the industrial computer through communication cables, and the industrial computer can obtain the horizontal plane displacement information of the robot's terminal axis.

[0016] As a further improvement of the present invention, the top surface of the platform is raised with a linear rib, the length direction of the linear rib is parallel to the length direction of the Y-axis guide bar, and the Y-axis scale grating is located on the outer wall side elevation of the linear rib.

[0017] The beneficial effect of adopting the above technical solution is that the linear convex rib is convenient for arranging the Y-axis scale grating on one side, and it is also convenient for the platform to provide a certain degree of semi-wrapped protection for the Y-axis scale grating and the Y-axis grating reading head.

[0018] As a further improvement of the present invention, the shaft sleeve combination structure includes a locking flange, a shaft sleeve, a bearing, and an optical axis which are coaxial with each other. The locking flange is wrapped and assembled on the robot terminal shaft, the shaft sleeve is fixed under the locking flange, the bearing is fixed in the X-axis slider seat, and the optical axis passes through the shaft sleeve and the bearing; the optical axis has a Z-axis linear lifting freedom relative to the shaft sleeve, and the optical axis has a rotational freedom around the Z-axis relative to the bearing.

[0019] The beneficial effect of adopting the above technical solution is: through the connection between the shaft sleeve combination structure and the robot end shaft, the two degrees of freedom of the SCARA robot, movement along the Z-axis direction and rotation of the robot end shaft, are released, satisfying the SCARA robot to perform various actions on the robot detection device.

[0020] As a further improvement of the present invention, the grating measurement mechanism is connected to an industrial computer via a cable, and the industrial computer can obtain the displacement information of the robot's terminal axis in the horizontal plane; the industrial computer signal is connected to the robot control system, and the industrial computer and the robot control system collect data and issue instructions.

[0021] The beneficial effects of adopting the above technical solution are: the industrial computer and the robot control system can control signals and collect data. The control signal includes the end process signal, and the industrial computer can also return data to make quality judgments and indicators of robot positioning accuracy.

[0022] A SCARA robot precision detection and compensation method uses the above SCARA robot precision detection device, and the SCARA robot precision detection and compensation method comprises: step S1: utilizing a shaft sleeve combination structure to assemble with a robot end shaft of a SCARA robot to perform zero return calibration; step S2: starting the SCARA robot to sequentially traverse various command positions according to a preset command trajectory; step S3: comparing the actual arrival position of the robot end shaft of the SCARA robot with the command position to obtain a positioning error of the SCARA robot; step S4: starting the SCARA robot again to perform traversal measurement, evaluate the improvement of positioning accuracy and the convergence of compensation effect, and verify the compensation effect.

[0023] The beneficial effect of adopting the above technical solution is: the method innovatively adopts the error compensation solution of the embedded module. The method uses the embedded module to realize real-time communication between the detection device and the robot control system, and completes the detection of robot positioning accuracy and compensation of geometric errors through the "detection-compensation-verification" cycle process.

[0024] As a further improvement of the present invention, step S4 also includes step S5, step S5: if the positioning accuracy of the SCARA robot reaches the preset standard or the compensation effect tends to be stable, the cyclic measurement is terminated and an output result is generated, the output result includes measurement data, compensation effect evaluation and final positioning accuracy report; if the positioning accuracy of the SCARA robot does not reach the preset standard or the compensation effect does not converge, the cyclic measurement, analysis and compensation are continued until the preset accuracy requirements are met or the preset upper limit of the number of cycles is reached.

[0025] As a further improvement of the present invention, the SCARA robot signal is connected to the robot control system, and the preset expected instruction position is input into the robot control system in step S1; and / or the grating measurement mechanism is used in real time and dynamically to capture and record the actual position data of the robot terminal axis of the SCARA robot at each instruction position in step S2; and / or the positioning error of the SCARA robot is used to estimate the structural error and joint zero point error of the SCARA robot in step S3. After each round of measurement cycle, the positioning error of the SCARA robot is fed back to the robot control system and triggers a compensation program, and the structural parameters and joint zero point of the SCARA robot are fine-tuned to compensate for the positioning error of the robot terminal axis of the SCARA robot. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is a block diagram of an implementation of the SCARA robot precision detection device of the present application;

[0028] Figure 2 It is an application schematic diagram of an implementation mode of the SCARA robot precision detection device of the present application;

[0029] Figure 3 It is a stereogram of an implementation of the SCARA robot precision detection device of the present application;

[0030] Figure 4 It is a partial enlarged view of point A of an implementation manner of the SCARA robot precision detection device of the present application;

[0031] Figure 5 It is a side view of an embodiment of the SCARA robot precision detection device of the present application;

[0032] Figure 6 It is a three-dimensional diagram of a connecting bridge and a shaft sleeve combination structure of an implementation method of a SCARA robot precision detection device of the present application;

[0033] Figure 7 It is a front view of an implementation of the SCARA robot precision detection device of the present application;

[0034] Figure 8It is a BB cross-sectional view of an implementation manner of the SCARA robot precision detection device of the present application;

[0035] Fig. 9 It is a three-dimensional diagram of a bracket of an embodiment of the SCARA robot precision detection device of the present application;

[0036] Fig.10 It is a partial enlarged view of position C of an implementation manner of the SCARA robot precision detection device of the present application;

[0037] Fig.11 It is a front view of a shaft sleeve assembly structure of an implementation mode of the SCARA robot precision detection device of the present application;

[0038] Fig.12 It is a DD cross-sectional view of an implementation mode of the SCARA robot precision detection device of the present application;

[0039] Fig.13 It is an exploded view of a shaft sleeve assembly structure of an implementation mode of the SCARA robot precision detection device of the present application;

[0040] Fig.14 It is a flow chart of an implementation method of the SCARA robot precision detection and compensation method of the present application.

[0041] 1- bracket; 101- angle steel section; 102- external threaded part; 103- square tube; 104- internal threaded part; 2- platform; 201- linear convex rib; 3- Y-axis guide rail; 4- connecting bridge; 5- X-axis slider seat; 6- shaft sleeve combination structure; 601- optical axis; 6011- step surface; 602- bearing; 603- bearing locking nut; 604- bearing cover; 605- shaft sleeve; 606- locking flange; 6061- longitudinal slit; 6062 - transverse slit; 6063-through cavity; 7-X-axis guide rail; 8-Y-axis grating assembly; 801-Y-axis scale grating; 802-Y-axis grating reading head; 9-X-axis grating assembly; 901-X-axis scale grating; 902-X-axis grating reading head; 10-industrial computer; 1001-embedded error compensation module; 11-robot control system; 12-base; 13-SCARA robot; 1301-robot end shaft; 14-transition piece. DETAILED DESCRIPTION

[0042] The present invention is further described in detail below in conjunction with specific embodiments:

[0043] In order to achieve the purpose of the present invention, a SCARA robot precision detection device includes: a horizontal translation mechanism, including a horizontal and mutually perpendicular X-axis translation component and a Y-axis translation component; a longitudinal release mechanism, located on the horizontal translation mechanism, the longitudinal release mechanism has a shaft sleeve combination structure 6, the shaft sleeve combination structure 6 can be movably assembled with the robot end shaft 1301 of the SCARA robot 13, and the robot end shaft 1301 has mechanical freedom along the Z-axis linear lifting and lowering and around the Z-axis rotation in the shaft sleeve combination structure 6; a grating measurement mechanism, including an X-axis grating component 9 and a Y-axis grating component 8 respectively arranged in parallel with the X-axis translation component and the Y-axis translation component, the grating measurement mechanism can detect the respective readings of the longitudinal release mechanism along the X-axis and the Y-axis on the horizontal plane.

[0044] Among them, the X-axis, Y-axis, and Z-axis have the same essential meanings as the X-direction, Y-direction, and Z-direction respectively. The X-axis and Y-axis are two mutually perpendicular directions in the horizontal plane, and the Z-axis is the vertical plumb direction.

[0045] The SCARA robot precision detection device constitutes a detection platform, which only detects the positioning accuracy of the SCARA robot 13 in the horizontal plane, that is to say, only detects the movement accuracy in the X and Y directions. However, the SCARA robot 13 is a four-degree-of-freedom multi-joint robot, and it can also have up and down movement of the Z axis and rotational movement of the robot terminal shaft 1301. Therefore, the detection platform does not detect the rotation accuracy of the Z axis direction and the robot terminal shaft 1301, but in order to meet the detection needs, it is necessary to release these two mechanical degrees of freedom to avoid interference and damage to the horizontal translation mechanism and the grating measurement mechanism. The SCARA robot 13 is multi-axis linkage coupled, but the technical solution of the present application does not detect the Z axis movement and the rotation of the robot terminal shaft 1301.

[0046] In other embodiments of the present invention, a platform 2 is fixed below the horizontal translation mechanism, a bracket 1 is provided below the platform 2, and the bracket 1 has a plurality of height adjustment rods that can adjust the angle between the top surface of the platform 2 and the horizontal plane.

[0047] like Fig. 9 , Fig.10 As shown, the main body of the bracket 1 is composed of a square tube 103, and the top of the square tube 103 is cut to form an angle steel section 101. The angle steel section 101 is used to limit and protect the four corners of the platform 2.

[0048] Fig.10 As shown, the height adjustment rod uses the principle of a threaded knob, and there can be three height adjustment rods. The connection lines between the three height adjustment rods form a triangle, and there can be a column directly below each height adjustment rod to ensure the structural strength of the bracket 1. The height adjustment rod includes an external threaded member 102 and an internal threaded member 104 that are threadedly assembled with each other.

[0049] In other embodiments of the present invention, the Y-axis translation assembly includes at least two mutually parallel Y-axis guide bars 3, the X-axis translation assembly includes a connecting bridge 4, an X-axis guide bar 7 is arranged on the top of the connecting bridge 4, the connecting bridge 4 and the Y-axis guide bar 7 are movably assembled through a slider, the X-axis guide bar 7 is movably assembled with an X-axis slider seat 5, and the top of the X-axis slider seat 5 is assembled with a shaft sleeve combination structure 6.

[0050] The platform 2 and the connecting bridge 4 can both be made of marble, so that the platform 2 and the connecting bridge 4 have better stability and straightness.

[0051] like Figure 1 , Figure 2 The bracket 1 and platform 2 shown in the figure have three adjustable supports on the bracket 1, and the platform 2 is placed on the bracket 1. The upper surface of the platform 2 is adjusted to be parallel to the horizontal plane through the three adjustable supports. Two Y-axis guide bars 3 and a connecting bridge 4 are arranged in an H shape. The connecting bridge 4 can slide along the Y-axis guide bar 3 in the Y-axis direction. The X-axis slider seat 5 can slide along the X-axis guide bar 7.

[0052] In some other embodiments of the present invention, the X-axis grating assembly 9 includes an X-axis scale grating 901 and an X-axis grating reading head 902, the X-axis scale grating 901 is fixed to the side elevation of the outer wall of the connecting bridge 4, and the X-axis grating reading head 902 is fixed to one side of the X-axis slider seat 5 and extends downward; the Y-axis grating assembly 8 includes a Y-axis scale grating 801 and a Y-axis grating reading head 802, the Y-axis scale grating 801 is fixed to the surface of the platform 2, and the Y-axis grating reading head 802 is fixed to one end of the connecting bridge 4 and extends downward.

[0053] The Y-axis scale grating 801 is installed along one side of the platform 2 and is parallel to the Y-axis guide rail 3. The Y-axis scale reading head 802 is installed on one side of the connecting bridge 4 and can move with the movement of the connecting bridge 4 and can accurately read the displacement of the connecting bridge 4. The X-axis scale grating 901 is installed along one side of the connecting bridge 4 and is parallel to the X-axis guide rail 7. The X-axis scale reading head 902 is installed on the side of the X-axis slider seat 5 and can move with the movement of the X-axis slider seat 5 and can accurately read the displacement of the X-axis slider seat 5.

[0054] In some other embodiments of the present invention, the top surface of the platform 2 is raised with a linear rib 201, the length direction of the linear rib 201 is parallel to the length direction of the Y-axis guide bar 3, and the Y-axis scale grating 801 is located on the outer wall side elevation of the linear rib.

[0055] A recessed area for accommodating the Y-axis scale grating 801 is formed on one side of the linear rib 201, so that the Y-axis scale grating 801 and the Y-axis grating reading head 802 can be half-wrapped and protected by the platform 2, thereby preventing the Y-axis grating reading head 802 from being damaged by bumps.

[0056] like Figure 4 As shown, one side of the X-axis slider seat 5 is assembled with the X-axis grating reading head 902 by means of a transition piece 14. The transition piece 14 can offset the vertical thickness of the connecting bridge 4, so that the X-axis grating reading head 902 can correspond horizontally with the X-axis scale grating 901.

[0057] In some other embodiments of the present invention, the sleeve assembly structure 6 includes a coaxial locking flange 606, a sleeve 605, a bearing 602, and an optical axis 601. The locking flange 606 wraps and assembles the robot terminal shaft 1301, the sleeve 605 is fixed under the locking flange 606, the bearing 602 is fixed in the X-axis slider seat 5, and the optical axis 601 passes through the sleeve 605 and the bearing 602; the optical axis 601 has a Z-axis linear lifting freedom relative to the sleeve 605, and the optical axis 601 has a rotational freedom around the Z-axis relative to the bearing 602.

[0058] like Fig.13 As shown, the robot end shaft 1301 is connected to the X-axis slider seat 5 through a sleeve assembly structure 6. The sleeve assembly structure 6 is composed of an optical axis 601, a bearing 602, a bearing locking nut 603, a bearing pressure cover 604, a sleeve 605 and a locking flange 606. The inner ring of the bearing 602 is interference fit with the optical axis 601 and is locked by the bearing locking nut 603. The outer ring of the bearing 602 is interference fit with the blind hole on the upper surface of the X-axis slider seat 5. The bearing pressure cover 604 presses the bearing 602 in the blind hole, so that the optical axis 601 can rotate around the X-axis slider seat 5. The sleeve 605 is sleeved on the optical axis 601 and can slide up and down along the optical axis 601. The locking flange 606 is locked by means of deformation of the bolts, one end of the locking flange 606 is locked to the outer wall of the sleeve 605, and the other end of the locking flange 606 is locked to the outer wall of the robot terminal shaft 1301, thereby realizing the structural connection between the robot terminal shaft 1301 and the robot detection device.

[0059] The optical axis 601 has a stepped surface 6011 for fitting with the bearing 602. In addition, the number of the bearings 602 may be two.

[0060] The locking flange 606 can be an integral metal part. In order to allow the locking flange 606 to have radial deformation locking force, the locking flange 606 has a longitudinal slit 6061 and a transverse slit 6062. The locking flange 606 has a through cavity 6063 that is in direct contact with the robot terminal shaft 1301. The longitudinal slit 6061 cuts off and connects the inner wall and the outer wall of the locking flange 606, and the transverse slit 6062 is vertically connected to the longitudinal slit 6061 along the radial direction of the locking flange 606.

[0061] In some other embodiments of the present invention, the grating measurement mechanism is connected to an industrial computer 10 via a cable, and the industrial computer 10 can obtain the displacement information of the robot's terminal axis 1301 in the horizontal plane; the industrial computer 10 signal is connected to the robot control system 11, and the industrial computer 10 and the robot control system 11 collect data and issue instructions.

[0062] The actions performed by the robot's terminal axis 1301 can all read the displacement of the SCARA robot 13 terminal in the XY plane through the Y-axis grating reading head 802 and the X-axis grating reading head 902. The Y-axis grating reading head 802 and the X-axis grating reading head 902 are connected to the industrial computer 10 through communication cables, and the industrial computer 10 can obtain the horizontal plane displacement information of the robot's terminal axis 1301.

[0063] The industrial computer 10 further includes an embedded error compensation module 1001. A base 12 is fixed to the bottom of the SCARA robot 13 to adapt to the height of the platform 2.

[0064] A SCARA robot precision detection and compensation method uses the above SCARA robot precision detection device, and the SCARA robot precision detection and compensation method comprises: step S1: utilizing a shaft sleeve combination structure 6 to assemble with a robot end shaft 1301 of a SCARA robot 13 to perform zero calibration; step S2: starting the SCARA robot 13 to sequentially traverse each instruction position according to a preset instruction trajectory; step S3: comparing the actual arrival position of the robot end shaft 1301 of the SCARA robot 13 with the instruction position to obtain a positioning error of the SCARA robot 13; step S4: starting the SCARA robot 13 again to perform traversal measurement, evaluating the improvement of positioning accuracy and the convergence of compensation effect, and verifying the compensation effect.

[0065] In some other embodiments of the present invention, step S4 also includes step S5, step S5: if the positioning accuracy of the SCARA robot 13 reaches the preset standard or the compensation effect tends to be stable, the cyclic measurement is terminated and an output result is generated, the output result includes measurement data, compensation effect evaluation and final positioning accuracy report; if the positioning accuracy of the SCARA robot 13 does not reach the preset standard or the compensation effect does not converge, the cyclic measurement, analysis and compensation are continued until the preset accuracy requirements are met or the preset upper limit of the number of cycles is reached.

[0066] In some other embodiments of the present invention, the SCARA robot 13 signal is connected to the robot control system 11, and the preset expected instruction position is input into the robot control system 11 in step S1; the grating measurement mechanism is used to capture and record the actual position data of the robot terminal shaft 1301 of the SCARA robot 13 at each instruction position in real time and dynamically in step S2; the positioning error of the SCARA robot 13 is used to estimate the structural error and joint zero point error of the SCARA robot 13 in step S3, and the positioning error of the SCARA robot 13 is fed back to the robot control system 11 after each round of measurement cycle and triggers the compensation program, and the structural parameters and joint zero point of the SCARA robot 13 are fine-tuned to compensate for the positioning error of the robot terminal shaft 1301 of the SCARA robot 13.

[0067] As a non-limiting example, the detection platform of the present application adopts a solution of replacing the grating measurement system with other types of linear detection devices such as a magnetic grating measurement system. The detection platform adopts a solution of increasing or decreasing the number of linear guide rails or linear guide sleeves, but does not change the type of freedom of motion of the detection platform. The detection platform adopts other communication methods or methods with the robot control system, but does not change the data transmission and processing logic, including but not limited to using wireless communication instead of wired communication, still using wired communication but changing the communication protocol, etc.

[0068] The SCARA robot precision detection and compensation method can obtain the robot's running accuracy on the XY plane (i.e., horizontal plane) through the plane positioning accuracy detection platform (i.e., SCARA robot precision detection device, referred to as: detection platform), and can also compensate for the positioning accuracy error, such as Fig.14 As shown, a specific operation process and method are as follows:

[0069] Step S1: Before performing precision measurement, the detection platform needs to be manually zeroed to ensure that it is in a zero position state, providing an accurate reference point for subsequent measurements. Subsequently, the robot end shaft 1301 is connected and locked with the locking flange 606 of the detection platform, and at the same time, a series of preset expected command positions are accurately input into the robot control system 11, laying a solid foundation for subsequent automated measurement and compensation.

[0070] Step S2: The system starts the SACRA robot 13 to traverse each command position in turn according to the preset command trajectory. In this process, the detection platform relies on the grating measurement mechanism to capture and record the actual position data of the end effector of the SACRA robot 13 at each command position in real time and dynamically. The robot control system 11 sends the current command position and data acquisition signal to the industrial computer 10 in real time according to the plan, and the industrial computer 10 immediately latches the current position after receiving the signal.

[0071] Step S3: The detection platform obtains the positioning error of the SACRA robot 13 by comparing the actual arrival position with the command position, and uses the data to accurately estimate the structural error and joint zero point error of the SACRA robot 13. These error data will be fed back to the robot control system 11 immediately after each round of measurement cycle and trigger the compensation program to achieve fine-tuning of the structural parameters and joint zero point of the SACRA robot 13 to compensate for the positioning error of the end of the SACRA robot 13 to the greatest extent.

[0072] Step S4: In order to verify the compensation effect, the system will start the SACRA robot 13 again to perform traversal measurement. The detection platform will record the actual position data of the end effector of the SACRA robot 13 again and compare it with the expected position data to evaluate the improvement of positioning accuracy and the convergence of compensation effect. If the positioning accuracy reaches the preset standard or the compensation effect tends to be stable, the system ends the loop and generates a comprehensive output result including detailed measurement data, compensation effect evaluation and final positioning accuracy report.

[0073] Step S5: If the positioning accuracy still does not meet the requirement or the compensation effect has not converged, the system will continue to perform cyclic measurement, analysis and compensation until the preset accuracy requirement is met or the preset upper limit of the number of cycles is reached.

[0074] like Figure 1 The characters shown are as follows: n: the number of instruction positions to be detected; p: i : The i-th instruction position; q i,k : The driving joint variables of the robot at the i-th command position; The actual arrival position of the robot under the i-th command position; ε: position error threshold. If the position error of the robot is detected to be lower than this threshold, the robot can pass the offline test; λ: compensation result convergence threshold. If the position error of the robot converges to this threshold after compensation, the error compensation is stopped and the robot positioning accuracy is judged to be poor; J i,k : The error Jacobian matrix of the robot at the i-th command position; k: k-th error compensation; Δp i,k : The position error of the robot in the plane; an estimate of the geometric error vector; An estimate of the structural error vector; Estimated value of the zero-point error vector of the driving joint; Δq k : The zero point vector of the driving joint after the kth error compensation. When k = 0, the initial result is zero; Δl k : The structural error vector after the kth error compensation. When k=0, the initial result is zero.

[0075] The SCARA robot precision detection device and precision detection compensation method of the present application have multiple technical benefits:

[0076] First, the cost-effectiveness and structure are optimized. Through structural optimization design, the bracket 1, platform 2, horizontal translation mechanism, and longitudinal release mechanism of the present application simplify redundant mechanical components and achieve a significant cost reduction. This improvement not only improves the economic efficiency of the equipment, but also makes the structure more compact and the transmission chain shorter, thereby significantly enhancing the reliability and stability of the equipment.

[0077] Secondly, space efficiency and flexibility. The small overall footprint allows it to be flexibly moved and installed in various production environments. This flexibility not only optimizes the spatial layout of the production line, but also facilitates rapid deployment at different production stages, improving overall production efficiency.

[0078] Again, ultra-high precision measurement. Using high-precision linear guide assembly technology, combined with precise mechanical coordination and advanced grating measurement mechanism, the equipment of this application can achieve micron-level measurement accuracy, providing a solid guarantee for the precise control of robot positioning accuracy.

[0079] From this, production line integration and efficient detection. The SCARA robot precision detection device of this application can be directly installed on the production line, seamlessly connected with the production line, realizing instant detection and significantly improving detection efficiency. At the same time, this feature also ensures the quality control of robot products when they are offline, providing strong support for improving product quality and production efficiency.

[0080] The device of the present application is simple and intuitive to operate. It only needs to connect the robot end shaft 1301 of the SCARA robot 13 and the cable plug to quickly start the measurement program and easily complete the precision detection, which greatly reduces the skill requirements for the operator, facilitates wide promotion and application, and reduces the labor cost of the enterprise.

[0081] Finally, the embedded error compensation module 1001 is added. This application proposes an innovative positioning accuracy detection and error compensation method. By realizing real-time communication between the detection platform and the robot control system, and the "detection-compensation-verification" cycle process method, the robot's position error can be detected quickly and efficiently, and error compensation can be implemented. The efficiency of this method enables it to meet the production rhythm requirements of the production line, thereby achieving effective control of the robot's offline positioning accuracy.

[0082] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it. They cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A SCARA robot precision detection device, characterized in that: include: A horizontal translation mechanism, comprising a horizontal and mutually perpendicular X-axis translation component and a Y-axis translation component; A longitudinal release mechanism is located on the horizontal translation mechanism, and the longitudinal release mechanism has a shaft sleeve combination structure, and the shaft sleeve combination structure can be movably assembled with the robot end shaft of the SCARA robot, and the robot end shaft has mechanical freedom of linear lifting along the Z axis and rotation around the Z axis in the shaft sleeve combination structure; The grating measuring mechanism comprises an X-axis grating component and a Y-axis grating component which are respectively arranged in parallel with the X-axis translation component and the Y-axis translation component. The grating measuring mechanism can detect the respective readings of the longitudinal release mechanism along the X-axis and the Y-axis on the horizontal plane.

2. The SCARA robot precision detection device according to claim 1, characterized in that: A platform is fixed below the horizontal translation mechanism, a bracket is arranged below the platform, and the bracket has a plurality of height adjustment rods, and the height adjustment rods can adjust the angle between the top surface of the platform itself and the horizontal plane.

3. The SCARA robot precision detection device according to claim 2, characterized in that: The Y-axis translation assembly includes at least two mutually parallel Y-axis guide bars, and the X-axis translation assembly includes a connecting bridge, an X-axis guide bar is arranged on the top of the connecting bridge, the connecting bridge and the Y-axis guide bar are movably assembled through a slider, the X-axis guide bar is movably assembled with an X-axis slider seat, and the top of the X-axis slider seat is assembled with a shaft sleeve combination structure.

4. The SCARA robot precision detection device according to claim 3, characterized in that: The X-axis grating assembly includes an X-axis scale grating and an X-axis grating reading head. The X-axis scale grating is fixed to the side elevation of the outer wall of the connecting bridge, and the X-axis grating reading head is fixed to one side of the X-axis slider seat and extends downward. The Y-axis grating assembly includes a Y-axis scale grating and a Y-axis grating reading head. The Y-axis scale grating is fixed on the surface of the platform, and the Y-axis grating reading head is fixed on one end of the connecting bridge and extends downward.

5. The SCARA robot precision detection device according to claim 4, characterized in that: The top surface of the platform is raised with a linear convex rib, the length direction of the linear convex rib is parallel to the length direction of the Y-axis guide rail, and the Y-axis scale grating is located on the side elevation of the outer wall of the linear convex rib.

6. The SCARA robot precision detection device according to claim 1, characterized in that: The shaft sleeve assembly structure includes a mutually coaxial locking flange, a shaft sleeve, a bearing, and an optical axis. The locking flange wraps and assembles the robot terminal shaft, the shaft sleeve is fixed under the locking flange, the bearing is fixed in the X-axis slider seat, and the optical axis passes through the shaft sleeve and the bearing; The optical axis has a Z-axis linear lifting freedom relative to the sleeve, and the optical axis has a rotational freedom around the Z-axis relative to the bearing.

7. The SCARA robot precision detection device according to claim 1, characterized in that: The grating measurement mechanism is connected to an industrial computer via a cable, and the industrial computer can obtain displacement information of the robot's terminal axis in the horizontal plane; The industrial computer is signal-connected to a robot control system, and the industrial computer and the robot control system collect data and issue instructions.

8. A SCARA robot precision detection compensation method, characterized in that: The SCARA robot precision detection device according to any one of claims 1 to 7 is used, and the SCARA robot precision detection compensation method comprises: Step S1: assemble the shaft sleeve assembly structure with the robot end shaft of the SCARA robot to perform zero return calibration; Step S2: Start the SCARA robot to traverse each command position in turn according to the preset command trajectory; Step S3: Compare the actual arrival position of the robot end axis of the SCARA robot with the command position to obtain the positioning error of the SCARA robot; Step S4: Start the SCARA robot again to perform traversal measurement, evaluate the improvement of positioning accuracy and the convergence of compensation effect, and verify the compensation effect.

9. The SCARA robot precision detection and compensation method according to claim 8, characterized in that: The step S4 further includes a step S5, wherein: If the positioning accuracy of the SCARA robot reaches the preset standard or the compensation effect tends to be stable, the cyclic measurement ends and an output result is generated, which includes measurement data, compensation effect evaluation and final positioning accuracy report; If the positioning accuracy of the SCARA robot does not meet the preset standard or the compensation effect does not converge, the measurement, analysis and compensation will be performed continuously until the preset accuracy requirement is met or the preset upper limit of the number of cycles is reached.

10. The SCARA robot precision detection and compensation method according to claim 8, characterized in that: The SCARA robot signal is connected to a robot control system, and in step S1, a preset desired command position is input into the robot control system; and / or In step S2, the grating measurement mechanism is used to capture and record the actual position data of the robot end axis of the SCARA robot at each command position in real time and dynamically; and / or In step S3, the positioning error of the SCARA robot is used to estimate the structural error and joint zero point error of the SCARA robot. After each measurement cycle, the positioning error of the SCARA robot is fed back to the robot control system and triggers a compensation program. The structural parameters and joint zero point of the SCARA robot are fine-tuned to compensate for the positioning error of the robot terminal axis of the SCARA robot.

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