Multi-axis combined rotary table laser non-contact dynamic calibration system and method

Abstract

The application discloses a kind of multi-axis combination rotary table laser non-contact dynamic calibration system and method, system includes laser transmitter component, air floatation vibration isolation platform, holographic receiving screen, light spot acquisition processing device and spatial position measuring device, calibration method includes the method steps of S1-S11.The multi-degree-of-freedom motion parameter of multi-axis combination rotary table is obtained by dynamic measurement, is fed back to multi-axis combination rotary table control system, and the deviation of target parameter is used as closed-loop feedback correction value, and the control precision of multi-axis combination rotary table is corrected, and multi-axis combination rotary table laser non-contact dynamic calibration is realized.The initial system comprehensive error constituted by light spot centroid positioning error, artificial visual error of target point measurement by instrument, and instrument error etc.is separated out by the comprehensive error compensation method of the application system, the solving precision of multi-axis coupling error is improved, and multi-axis collaborative calibration capability is improved.

Description

Technical Field

[0001] This invention relates to the field of precision testing and calibration technology for intelligent manufacturing equipment, and in particular to a multi-axis combined turntable laser non-contact dynamic calibration system and method. Background Technology

[0002] In the field of intelligent manufacturing, multi-axis rotary tables, with their multi-degree-of-freedom coordinated motion capabilities, are widely used in high-precision manufacturing scenarios such as aero-engine blade processing, spacecraft motion simulation, and semiconductor precision assembly. However, factors such as mechanical vibration, transmission backlash, thermal deformation, and dynamic loads can cause the actual posture of the rotary table to deviate from the theoretical trajectory, seriously affecting machining accuracy and assembly success rate.

[0003] Currently, multi-axis combined turntable calibration technology mainly relies on static, contact, single-axis, and offline compensation methods, but all have significant limitations. Static calibration cannot capture real-time errors under dynamic conditions, resulting in limited compensation effectiveness. Contact calibration, with its added sensor load, alters the turntable's dynamic characteristics, easily inducing vibrations in high-speed scenarios, and presents high installation complexity in industrial settings. Single-axis calibration cannot solve the problem of coordinated compensation for pose errors caused by multi-axis coupled motion. Offline model prediction compensation methods lack real-time closed-loop feedback, making it difficult to cope with sudden disturbances and other new operating conditions. While patent document CN104390633B discloses a non-contact mechanism spatial motion measurement device and its implementation method, proposing a non-contact laser spot measurement method, directly applying this method to the field of dynamic calibration of combined turntables has the following limitations:

[0004] 1. Compared with ordinary multi-axis motion mechanisms, combined turntables have higher precision and stricter requirements for dynamic error control. The CN104390633B solution lacks a comprehensive system error compensation mechanism and does not consider factors such as the calculation error of the spot centroid, the human visual error in the measurement of each target point in space, and the error of the measuring instrument. Moreover, the accumulation of comprehensive system errors will lead to the deterioration of dynamic measurement accuracy, making it unsuitable for the calibration of high-precision multi-axis combined turntables.

[0005] 2. The measurement system requires at least 3 sets of laser pointers, corresponding receiving screens, and spot acquisition and processing devices. In complex industrial sites, this is costly and complicated to deploy.

[0006] In summary, existing technologies cannot simultaneously meet the requirements of non-contact measurement of motion parameters of combined turntables, high-precision decoupling and collaborative calibration of multi-axis coupling errors, and lightweight integration and low-cost adaptation of calibration devices, thus affecting the process stability and dynamic pose accuracy of intelligent manufacturing equipment in high-precision collaborative operation scenarios. Summary of the Invention

[0007] To address the aforementioned shortcomings of existing technologies, this invention provides a multi-axis combined turntable laser non-contact dynamic calibration system and method, applicable to real-time pose error calibration of high-precision multi-degree-of-freedom motion systems.

[0008] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0009] A multi-axis combined turntable laser non-contact dynamic calibration system is provided, which includes at least one laser emitter assembly installed on the worktable of the multi-axis combined turntable, an air-bearing vibration isolation table disposed in the laser emission direction of the laser emitter assembly, a holographic receiving screen disposed on the worktable of the air-bearing vibration isolation table and corresponding to the laser emitter assembly, a spot acquisition and processing device and a spatial position measurement device corresponding to and electrically connected to the holographic receiving screen.

[0010] The spot acquisition and processing device is a platform for solving multi-axis coupling errors; the spot acquisition and processing device is used to acquire information on the position change of the light from the laser emitter component on the holographic receiving screen during the movement of the multi-axis combined turntable;

[0011] Both the holographic receiving screen and the multi-axis turntable base of the multi-axis combined turntable are equipped with several target points, and the spatial position measuring device is used to obtain the spatial coordinates of the target points.

[0012] Furthermore, the holographic receiving screen has three non-collinear first target points, each with a first reflective sheet, and the multi-axis turntable base of the multi-axis combined turntable has two second target points, each with a second reflective sheet.

[0013] Furthermore, when the multi-axis combined turntable is one-axis, two-axis, or three-axis, one set of laser emitter assembly, holographic receiving screen, and light spot acquisition and processing device is provided; when the multi-axis combined turntable is four-axis, five-axis, or six-axis, two sets of laser emitter assembly, holographic receiving screen, and light spot acquisition and processing device are provided.

[0014] Furthermore, the spatial position measuring device is a theodolite or a total station.

[0015] A calibration method for the aforementioned multi-axis combined turntable laser non-contact dynamic calibration system is provided, comprising the following steps:

[0016] S1: Measure the spatial coordinates of the three first target points on the holographic receiving screen using a spatial position measuring device, obtain the plane equation of the plane where the holographic receiving screen is located in the geodetic coordinate system A, and the homogeneous transformation matrix from the holographic receiving screen coordinate system M to the geodetic coordinate system A.

[0017] S2: Measure the laser emission point of the laser emitter assembly mounted on the multi-axis rotary table using a spatial position measuring device. KCoordinates are obtained by using a light spot acquisition and processing device to acquire the measured coordinates of the light spot on the holographic receiving screen. Combined with homogeneous transformation matrix Obtain the laser unit direction vector Coordinate representation in geodetic coordinate system A And determine the equation of the line where the laser is located;

[0018] S3: Based on the plane equation of the holographic receiving screen in the geodetic coordinate system A obtained in step S1 and the line equation of the laser obtained in step S2, obtain the theoretical spatial coordinates of the intersection point between the plane of the holographic receiving screen and the laser in the geodetic coordinate system A before the multi-axis combined turntable moves. According to the coordinates of the intersection points in theoretical space and the measured spot coordinates obtained in step S2 Calculate the overall system error ;

[0019] S4: Measure the two second target points on the multi-axis turntable base using a spatial position measuring device, and determine the homogeneous transformation matrix from the multi-axis turntable base coordinate system B to the geodetic coordinate system A. Simultaneously determine the homogeneous transformation matrix from the initial coordinate system C of the turntable to the geodetic coordinate system A. ;

[0020] S5: Combining steps S2 and S4, obtain the laser unit direction vector. Coordinates in the initial state coordinate system C and laser emission point K Coordinates in the initial state coordinate system C ;

[0021] S6: Construct the plane equation of the plane where the holographic receiving screen is located during the movement of the multi-axis combined turntable (1);

[0022] S7: Constructing a multi-axis combined turntable (1) Laser unit direction vector during motion and laser emission point K The representation in the coordinate system after the turntable's motion yields the unit direction vector during the motion of the multi-axis combined turntable (1). and laser emission point Coordinates in geodetic coordinate system A ;

[0023] S8: Based on steps S6 and S7, obtain the coordinates of the theoretical motion space intersection point of the plane where the laser and the holographic receiving screen (4) are located in the geodetic coordinate system A during the motion of the multi-axis combined turntable (1). ;

[0024] S9: Use the spot acquisition and processing device (5) to obtain the measured coordinates of the moving spot on the holographic receiving screen (4) during the movement of the multi-axis combined turntable (1). And transform it to the geodetic coordinate system A;

[0025] S10: Coordinates of the intersection point in the theoretical motion space obtained in step S8 Eliminate the system comprehensive error obtained in step S3 Then, combined with the measured coordinates of the moving light spot obtained in step S9 Establish the coordinates of the intersection points in the theoretical motion space. System comprehensive error Coordinates of the intersection point with the actual motion obtained from the actual shooting By applying the equations between them, the motion parameters of the multiple degrees of freedom can be obtained;

[0026] S11: Send the solved multi-degree-of-freedom motion parameters to the multi-axis combined turntable control system, calculate the closed-loop feedback correction value, and correct the control accuracy of the multi-axis combined turntable (1).

[0027] The beneficial effects of this invention are as follows:

[0028] This invention provides a method for improving the real-time decoupling accuracy of multi-axis coupling errors, a first in the field of multi-axis combined turntables. It employs a multi-axis coupling error decoupling method to establish a motion mathematical model of the multi-axis combined turntable and measurement calibration system. Simultaneously, it proposes an initial system comprehensive error compensation method to separate the system comprehensive error, which includes spot centroid positioning error, target measurement error, and instrument error. Combining these methods, the system comprehensive error is eliminated, and the multi-degree-of-freedom motion parameters are calculated. By combining these two improved methods, the method can be applied to the field of multi-axis combined turntables. Compared to directly using existing technologies, the real-time calculation accuracy of the dynamic pose error of the multi-axis combined turntable can be improved to within ±15″ / axis, representing an accuracy improvement of at least 60%.

[0029] The core idea of ​​the multi-axis coupling error decoupling method of this invention is as follows: In the geodetic coordinate system, the plane containing the laser and the holographic receiving screen has a unique spatial intersection point. The spatial coordinates of this intersection point can be obtained through two methods: 1. theoretical calculation; 2. actual measurement by the light spot acquisition and processing device. The spatial intersection point coordinates obtained through both methods are necessarily unique and equal in the geodetic coordinate system. The theoretically calculated spatial intersection point coordinates are functions of multi-degree-of-freedom motion parameters, specifically functions of pitch, yaw, roll, and translational motion along the x, y, and z axes. The spatial intersection point coordinates measured by the light spot acquisition and processing device are definite quantities. Therefore, an equation can be established to calculate the multi-degree-of-freedom motion parameters.

[0030] The core idea of ​​the initial system comprehensive error compensation method of this invention is as follows: Before the multi-axis combined turntable moves, in the geodetic coordinate system, the theoretical intersection point of the plane where the laser and the holographic receiving screen are located and the measured intersection point obtained by the spot acquisition and processing device are both constant values. The difference between the two is the system comprehensive error, which includes human visual errors caused by image processing and target measurement, instrument errors, etc. During the movement of the multi-axis combined turntable, removing this component from the theoretical intersection point information of the plane where the laser and the holographic receiving screen are located can eliminate the system comprehensive error, improve the accuracy of coupling error calculation, and avoid the accumulation of system comprehensive error.

[0031] The calibration system of this invention significantly reduces deployment complexity. Compared with traditional turntable calibration methods such as static, contact, single-axis, and offline compensation, the use of laser non-contact measurement technology can adapt to dynamic working conditions and eliminate real-time errors caused by dynamic interference such as mechanical vibration, transmission gaps, temperature drift, and load changes. Compared with the direct use of existing technology methods, the non-contact measurement components are reduced from at least 3 sets of laser-receiver groups to at least 1 set (3 degrees of freedom) and 2 sets (6 degrees of freedom), reducing system quality and cost by more than 40% and shortening deployment time by at least 50%.

[0032] This invention is applied to the dynamic closed-loop control of multi-axis combined turntables, which can enhance the real-time performance and stability of the multi-axis combined turntable control system. By dynamically measuring and obtaining the actual position and posture deviation of the turntable, the deviation data can be fed back to the multi-axis combined turntable control system as closed-loop error compensation for subsequent actions, thereby realizing dynamic adjustment and precise control of the turntable.

[0033] The multi-axis combined turntable laser non-contact dynamic calibration system and method of the present invention are applicable to real-time pose error calibration of high-precision multi-degree-of-freedom motion systems, especially for complex motion collaboration scenarios in intelligent manufacturing, including but not limited to: dynamic pose compensation of multi-axis combined turntables in the processing of complex curved surface components (such as aero-engine blades and optical freeform surfaces); online monitoring of multi-axis coupled motion accuracy of spacecraft motion simulation platforms; and multi-axis precision turntable control of precision assembly and high-precision grasping equipment for semiconductor devices.

[0034] The multi-axis combined turntable laser non-contact dynamic calibration system and method of the present invention are applicable to multi-axis turntables, including all "azimuth-pitch-roll-translation" multi-axis general turntables; only the program parameters need to be adjusted according to the different combination methods of the turntable and the mechanical structure parameters of the turntable. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the overall structure of the calibration system in this invention;

[0036] Figure 2 A schematic diagram showing the position of the first target point on the holographic receiving screen;

[0037] Figure 3 This is a diagram showing the coordinate system transfer relationship of a multi-axis rotary table.

[0038] The components include: 1. Multi-axis combined turntable; 2. Laser emitter assembly; 3. Air-bearing vibration isolation table; 4. Holographic receiving screen; 5. Light spot acquisition and processing device; 6. Target point; and 7. Spatial position measurement device. Detailed Implementation

[0039] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0040] like Figure 1 and 2 As shown, a multi-axis combined turntable laser non-contact dynamic calibration system includes at least one laser emitter assembly 2 mounted on the worktable surface of the multi-axis combined turntable 1, an air-bearing vibration isolation table 3 positioned in the laser emission direction of the laser emitter assembly 2, a holographic receiving screen 4 positioned on the worktable surface of the air-bearing vibration isolation table 3 and corresponding to the laser emitter assembly 2, a spot acquisition and processing device 5 electrically connected to each holographic receiving screen 4, and a spatial position measuring device 7. The holographic receiving screen 4 and the spot acquisition and processing device 5 are electrically connected. The spot acquisition and processing device 5 is a platform for solving multi-axis coupling errors and is used to acquire information on the change in the position of the light from the laser emitter assembly 2 on the holographic receiving screen 4 during the movement of the multi-axis combined turntable 1. Several target points 6 are set on both the holographic receiving screen 4 and the multi-axis turntable base of the multi-axis combined turntable 1. The spatial position measuring device 7 is used to acquire the spatial coordinates of the target points 6, and is preferably a theodolite or a total station. Both the laser emitter assembly 2 and the holographic receiver screen 4 are angle-adjustable. They are installed using an adjustable angle fixture to make the angle of the holographic receiver screen 4 adjustable, so that the laser is incident on the holographic receiver screen 4 as perpendicularly as possible and falls within the effective range of the holographic receiver screen 4.

[0041] In this embodiment, the holographic receiving screen 4 is provided with three non-collinear first target points, and each first target point is provided with a first reflective sheet. The multi-axis turntable base of the multi-axis combined turntable 1 is provided with two second target points, and each second target point is provided with a second reflective sheet.

[0042] In this embodiment, the number of laser emitter components 2, holographic receiver screens 4, and light spot acquisition and processing devices 5 is determined based on the number of axes of the multi-axis combined turntable 1. When the multi-axis combined turntable 1 has one, two, or three axes, one set of each of the laser emitter components 2, holographic receiver screens 4, and light spot acquisition and processing devices 5 is provided. When the multi-axis combined turntable 1 has four, five, or six axes, two sets of each of the laser emitter components 2, holographic receiver screens 4, and light spot acquisition and processing devices 5 are provided.

[0043] The multi-axis combined turntable 1 in this embodiment includes a rotating... A rotary table rotating around an axis. A tilting platform that rotates around an axis According to the technical solution, for a rotating turntable with a multi-axis rotation, it is necessary to obtain the theoretical coordinates of the intersection point of the laser emitted by the laser emitter assembly 2 and the holographic receiving screen 4 in the motion of the multi-axis combined turntable 1, as well as the measured coordinates of the moving light spot.

[0044] To facilitate the description of the calculation process, the following coordinate systems are established: Geodetic Coordinate System A (i.e., the total station coordinate system), Multi-axis Turntable Base Coordinate System B, Turntable Initial State Coordinate System C (physically located at the turntable's rotation center at the top layer of the multi-axis turntable base), Coordinate System D after the turntable undergoes pitch motion, Coordinate System E after the turntable undergoes yaw motion, Coordinate System F after the turntable undergoes roll motion, and holographic receiving screen Coordinate System M. Figure 3 This is a diagram showing the coordinate system transfer relationship of the multi-axis rotary table 1.

[0045] A calibration method for the aforementioned multi-axis combined turntable laser non-contact dynamic calibration system specifically includes the following steps:

[0046] S1: Use the spatial position measuring device 7 to measure the spatial coordinates of the three first target points on the holographic receiving screen 4, obtain the plane equation of the plane where the holographic receiving screen 4 is located in the geodetic coordinate system A, and the homogeneous transformation matrix from the holographic receiving screen coordinate system M to the geodetic coordinate system A.

[0047] Step S1 specifically includes:

[0048] S11: Use spatial position measuring device 7 to measure the spatial coordinates of the three first target points on the holographic receiving screen 4, and the normal vector of the plane where the holographic receiving screen 4 is located. for:

[0049] ;

[0050] In the formula, , , These are the coordinates of the three first target points, and the coordinates of these points are... Let M be the origin of the coordinate system M of the holographic receiving screen;

[0051] S12: Based on the normal vector of the plane where the holographic receiving screen 4 is located... and coordinates Determine the plane equation of the plane where the holographic receiving screen 4 is located;

[0052] ;

[0053] In the formula, These are the x-axis coordinates, y-axis coordinates, and z-axis coordinates of the origin M coordinate system of the holographic receiving screen, respectively. , , They are the plane normal vectors The components along the x-axis, y-axis, and z-axis in the coordinate system M of the holographic receiving screen;

[0054] S13: Assume that the coordinate system M of the holographic receiving screen is based on the geodetic coordinate system A, and is first rotated around the x-axis, y-axis, and z-axis of the geodetic coordinate system A by a fixed angle according to the x-axis, y-axis, and z-axis respectively. , , Then, a translation is performed to obtain the result. The translation amount between the holographic receiving screen coordinate system M and the geodetic coordinate system A is the spatial coordinate value of the origin of the holographic receiving screen coordinate system M in coordinate system A. Therefore, the homogeneous transformation matrix from the holographic receiving screen coordinate system M to the geodetic coordinate system A is... The parameterized form is:

[0055] ;

[0056] In the formula, , , Represent the x-axis, y-axis, and z-axis of the geodetic coordinate system A. The rotation angle is the x-axis of the geodetic coordinate system A. The rotation transformation matrix, The rotation angle is about the y-axis of the geodetic coordinate system A. The rotation transformation matrix, The rotation angle is about the z-axis of the geodetic coordinate system A. The rotation transformation matrix, To translate along the x-axis, y-axis, and z-axis of the geodetic coordinate system A respectively The translation transformation matrix;

[0057] Then the homogeneous transformation matrix The mathematical structure is as follows:

[0058] ;

[0059] in, Let be a rotation matrix. It is a translation vector;

[0060] ,in, , , These are the basic rotation matrices about the x-axis, y-axis, and z-axis, respectively:

[0061] ;

[0062] ;

[0063] ;

[0064] The homogeneous transformation matrix is ​​constructed by matrix multiplication. :

[0065] ;

[0066] S14: Since the plane where the holographic receiving screen 4 is located is the xoz plane of the holographic receiving screen coordinate system M, that is, the plane normal vector Let the y-axis direction be the coordinate system M of the holographic receiving screen. Therefore, establish the plane normal vector. With homogeneous transformation matrix The equation relationship between them:

[0067] ;

[0068] This yields the system of equations:

[0069] ;

[0070] Solve the above system of equations to calculate the rotation angle. , , And input the specific homogeneous transformation matrix. In the process, the homogeneous transformation matrix from the holographic receiving screen coordinate system M to the geodetic coordinate system A is obtained. ;

[0071] S2: Measure the laser emission point of the laser emitter assembly 2 mounted on the multi-axis rotary table 1 using the spatial position measuring device 7. The coordinates are obtained by using the light spot acquisition and processing device 5 to acquire the measured coordinates of the light spot on the holographic receiving screen 4. Combined with homogeneous transformation matrix Obtain the laser unit direction vector Representation in geodetic coordinate system A And determine the equation of the line where the laser is located;

[0072] S21: Measure the laser emission point of the laser emitter assembly 2 mounted on the multi-axis rotary table 1 using the spatial position measuring device 7. Obtain the laser emission point Laser emission point in geodetic coordinate system A coordinate ;

[0073] S22: The light spot acquisition and processing device 5 acquires the laser light spot on the holographic receiving screen 4. Measured light spot coordinates in the coordinate system M of the holographic receiving screen The measured light spot coordinates The conversion to geodetic coordinate system A is as follows:

[0074] ;

[0075] In the formula, For laser spot Coordinates in geodetic coordinate system A;

[0076] S23: Based on the laser emission point in geodetic coordinate system A coordinates and coordinates Determine the unit direction vector of the laser in the geodetic coordinate system A. ;

[0077] ;

[0078] And based on the bit direction vector Determine the equation of the line containing the laser beam:

[0079] ;

[0080] In the formula, , , Unit direction vectors The components along the x, y, and z axes of the geodetic coordinate system A; , , These are the laser emission points. The x-axis coordinates, y-axis coordinates, and z-axis coordinates of the geodetic coordinate system A; , , These are the x-axis, y-axis, and z-axis coordinates of any point on the line where the laser is located in the geodetic coordinate system A;

[0081] S3: Based on the plane equation of the holographic receiving screen 4 obtained in step S1 and the line equation of the laser obtained in step S2, obtain the theoretical spatial intersection coordinates of the plane of the holographic receiving screen 4 and the laser in the geodetic coordinate system A before the multi-axis combined turntable 1 moves. Based on the theoretical spatial intersection coordinates and the measured spot coordinates obtained in step S2... Calculate the overall system error ;

[0082] S31: Based on the plane equation of the holographic receiving screen 4 in the geodetic coordinate system A obtained in step S1 and the line equation of the laser obtained in step S2, obtain the theoretical spatial intersection coordinates of the laser and the plane of the holographic receiving screen 4 before the multi-axis combined turntable 1 moves in the geodetic coordinate system A. Specifically:

[0083] Based on the plane equation of the plane where the holographic receiving screen 4 is located in the geodetic coordinate system A and the equation of the line where the laser is located, a system of equations is established, and the coordinates of the intersection point in theoretical space are obtained by solving the equations. ;

[0084] ;

[0085] S32: Combined with the measured spot coordinates obtained in step S2 To obtain the comprehensive system error caused by image processing, human error in measurement, instrument error, etc. The specific calculation system comprehensive error The formula is as follows:

[0086] ;

[0087] S4: Measure the two second target points on the multi-axis turntable base using the spatial position measuring device 7, and determine the homogeneous transformation matrix from the multi-axis turntable base coordinate system B to the geodetic coordinate system A. Simultaneously, based on the known mechanical parameters of the multi-axis combined turntable 1, determine the homogeneous transformation matrix from the initial state coordinate system C (the origin of which is located at the rotation center of the top layer of the multi-axis turntable base) to the geodetic coordinate system A. ;

[0088] S41: Before the multi-axis combined turntable 1 moves, each axis is zeroed. Two second target points are set on the multi-axis turntable base. The second target point Q, which is closer to the x-axis end of the geodetic coordinate system A, is used as the origin of the multi-axis turntable base coordinate system B. The spatial coordinates of the two second target points are measured, and the y-axis angle between the multi-axis turntable base coordinate system B and the geodetic coordinate system A is calculated. Then the homogeneous transformation matrix of the multi-axis turntable base coordinate system B in the geodetic coordinate system A is... for:

[0089] ;

[0090] In the formula, Let z be the z-axis of the geodetic coordinate system A, and let the angle of rotation about the z-axis be the angle between the y-axis of the multi-axis turntable base coordinate system B and the geodetic coordinate system A. ; These are the x-axis coordinates, y-axis coordinates, and z-axis coordinates of the second target point Q in the geodetic coordinate system A, respectively.

[0091] S42: The initial state coordinate system C of the turntable is obtained by translating the multi-axis turntable base coordinate system B along the x-axis, y-axis, and z-axis directions. The homogeneous transformation matrix of the initial state coordinate system C of the turntable in the multi-axis turntable base coordinate system B. for:

[0092] ;

[0093] In the formula, These are the three-axis offsets of the initial state coordinate system C of the turntable, obtained by offsetting the multi-axis turntable base coordinate system B along its x, y, and z axes. This information can be obtained through multi-axis...

[0094] Obtain the parameter manual for combined turntable 1;

[0095] S43: Based on the homogeneous transformation matrix of the multi-axis turntable base coordinate system B in the geodetic coordinate system A. The homogeneous transformation matrix of the initial state coordinate system C of the turntable in the multi-axis turntable base coordinate system B. Determine the homogeneous transformation matrix from the initial coordinate system C of the turntable to the geodetic coordinate system. ;

[0096] ;

[0097] S5: Combining steps S2 and S4, obtain the laser unit direction vector. Coordinates in the initial state coordinate system C and laser emission point K Coordinates in the initial state coordinate system C ;

[0098] ;

[0099] ;

[0100] In the formula, Let be the unit direction vector of the laser in the initial state coordinate system C;

[0101] S6: Construct the plane equation of the plane containing the holographic receiving screen 4 during the movement of the multi-axis combined turntable 1; specifically:

[0102] Before and after the multi-axis combined turntable 1 moves, the relative position of the holographic receiving screen 4 and the spatial position measuring device 7 remains unchanged, and the plane equation of the plane on which the holographic receiving screen 4 is located is consistent with the plane equation of the plane on which the holographic receiving screen 4 is located determined in step S12; the specific plane equation is as follows:

[0103] ;

[0104] S7: Since the laser emitter assembly 2 is relatively stationary to the worktable surface of the multi-axis combined turntable 1 during its movement, the unit direction vector of the laser can be obtained. The representation of the laser emission point K in the coordinate system after the turntable moves. The coordinate system after the turntable moves includes the coordinate system D after the turntable pitches, the coordinate system E after the turntable yaws, and the coordinate system F after the turntable rolls.

[0105] Before and after the multi-axis combined turntable 1 moves, the laser emitter assembly 2 is fixedly connected to the top turntable body of the multi-axis turntable base. Therefore, the following applies:

[0106] ;

[0107] ;

[0108] In the formula, Indicates the laser emission point The coordinates of the turntable in the initial state coordinate system C before the multi-axis combined turntable 1 moves; laser direction vector The unit direction vector in coordinate system F after the turntable undergoes multi-degree-of-freedom motion. Laser emission point The coordinates in coordinate system F after the turntable undergoes multi-degree-of-freedom motion;

[0109] unit direction vector and coordinates Switch to geodetic coordinate system A:

[0110] ;

[0111] ;

[0112] in: The laser direction vector during the movement of the multi-axis combined turntable 1 The unit direction vector in the geodetic coordinate system A The laser emission point during the turntable's movement Coordinates in geodetic coordinate system A The laser emission point is the point where the multi-axis rotary table 1 moves during its motion.

[0113] Let be the homogeneous transformation matrix from coordinate system D to coordinate system C of the turntable after the turntable undergoes pitch motion. , Let x be the x-axis of the initial coordinate system C of the turntable, representing the pitch motion that occurs. For pitching motion;

[0114] Let be the homogeneous transformation matrix from coordinate system E after the turntable undergoes yaw motion to coordinate system D after the turntable undergoes pitch motion. , Let z be the z-axis of coordinate system D after the turntable undergoes pitch motion, i.e., the yaw motion that occurs. This refers to the yaw motion.

[0115] Let be the homogeneous transformation matrix from coordinate system F after the turntable undergoes roll motion to coordinate system E after the turntable undergoes yaw motion. , Let y be the coordinate system E after the turntable undergoes yaw motion, i.e., the rolling motion that occurs. This refers to the amount of rolling motion;

[0116] Thus, the unit direction vector during the motion of the multi-axis combined turntable 1 is determined. and laser emission point Coordinates in geodetic coordinate system A This information is a function that includes pitch, yaw, and roll motion.

[0117] S8: Based on steps S6 and S7, obtain the theoretical motion space coordinates of the intersection point of the laser and the plane containing the holographic receiving screen 4 in the geodetic coordinate system A during the motion of the multi-axis combined turntable 1. ;

[0118] S81: Based on the coordinates of the laser emission point and unit direction vector Determine the equation of the line along which the laser beam lies during the motion of the multi-axis rotary table 1:

[0119] ;

[0120] In the formula, Laser emission point The x-axis coordinates in the geodetic coordinate system A. Laser emission point The y-axis coordinates in geodetic coordinate system A; Indicates the laser emission point The z-axis coordinates in the geodetic coordinate system A; , , These are the laser direction vectors during the movement of the multi-axis combined turntable 1. The components along the x-axis, y-axis, and z-axis in the geodetic coordinate system A;

[0121] S82: Based on the plane equation of the plane where the holographic receiving screen 4 is located and the equation of the straight line where the laser is located during the motion of the multi-axis combined turntable 1, establish a system of equations and solve for the coordinates of the theoretical motion space intersection point of the laser and the plane where the holographic receiving screen 4 is located during the motion of the multi-axis combined turntable 1 in the geodetic coordinate system A. ;

[0122] ;

[0123] S9: Use the spot acquisition and processing device 5 to obtain the measured coordinates of the moving spot on the holographic receiving screen 4 during the movement of the multi-axis combined turntable 1. And transform it to the geodetic coordinate system A; specifically:

[0124] The light spot image information on the holographic receiving screen 4 is acquired by the light spot acquisition and processing device 5, and the measured coordinates of the moving light spot on the holographic receiving screen 4 are obtained through image processing. And the measured coordinates of the moving light spot Transform to geodetic coordinate system A;

[0125] ;

[0126] S10: Coordinates of the intersection point in the theoretical motion space obtained in step S8 Eliminate the system comprehensive error obtained in step S3 Then, combined with the measured coordinates of the moving light spot obtained in step S9 Establish the coordinates of the intersection points in the theoretical motion space. System comprehensive error Coordinates of the intersection point with the actual motion obtained from the actual shooting The equations between them are used to solve for the multi-degree-of-freedom motion parameters; the multi-degree-of-freedom motion parameters include: pitch motion. Yaw motion and rolling motion ;

[0127] ;

[0128] Through steps S1 to S9, the theoretical spatial coordinates of the intersection point between the laser and the holographic receiving screen 4 in the plane of the multi-axis combined turntable 1 in the geodetic coordinate system A during their motion were obtained. Coordinates of the intersection point with the actual motion The coordinates of the intersection points in the theoretical motion space It is a function of the three-degree-of-freedom motion quantities. Also, note the coordinates of the intersection points in the theoretical motion space. Remove the system comprehensive error obtained in step S3. ;

[0129] Establish the coordinates of the intersection points in the theoretical motion space System comprehensive error Coordinates of the intersection point with the actual motion obtained from the actual shooting The equation relationship between them:

[0130] ;

[0131] The equation relating the theoretical spatial coordinates of the laser's intersection with the receiving plane, the actual spatial coordinates of the intersection obtained from actual imaging, and the system's overall error input is used to express this relationship. A system of three linear equations was established to solve for the multi-degree-of-freedom motion parameters of the multi-axis combined turntable 1: pitch motion. Yaw motion and rolling motion ;

[0132] S11: Send the solved multi-degree-of-freedom motion parameters to the multi-axis combined turntable control system, calculate the closed-loop feedback correction value, and correct the control accuracy of the multi-axis combined turntable 1.

[0133] In the specific correction process, the difference between the target parameters preset by the multi-axis combined turntable control system and the actual solved multi-degree-of-freedom motion parameters is the multi-degree-of-freedom motion disturbance of the multi-axis combined turntable 1 under the influence of external factors such as mechanical vibration, transmission clearance, temperature drift, and load change. The multi-degree-of-freedom motion disturbance is used as the closed-loop feedback correction value of the multi-axis combined turntable to correct the control accuracy of the multi-axis combined turntable 1.

Claims

1. A multi-axis combined turntable laser non-contact dynamic calibration system, characterized in that, The application relates to a laser spot measurement device for a multi-axis combined rotary table (1), which comprises at least one laser emitter assembly (2) installed on a workbench of the multi-axis combined rotary table (1), an air floating vibration isolation table (3) arranged in the laser emission direction of the laser emitter assembly (2), a holographic receiving screen (4) arranged on a workbench of the air floating vibration isolation table (3) and corresponding to the laser emitter assembly (2), a light spot collection and processing device (5) corresponding to the holographic receiving screen (4) and electrically connected to the holographic receiving screen (4), and a spatial position measuring device (7). The light spot collection and processing device (5) is a multi-axis coupling error solving platform; the light spot collection and processing device (5) is used for acquiring light spot position change information of laser light of the laser emitter assembly (2) on the holographic receiving screen (4) during movement of the multi-axis combined rotary table (1). A plurality of target points (6) are arranged on the holographic receiving screen (4) and a multi-axis rotary table base of the multi-axis combined rotary table (1); and the spatial position measuring device (7) is used for acquiring spatial coordinates of the plurality of target points (6). Three first target points which are not collinear are arranged on the holographic receiving screen (4), and a first reflecting sheet is arranged on each of the first target points; two second target points are arranged on the multi-axis rotary table base of the multi-axis combined rotary table (1), and a second reflecting sheet is arranged on each of the second target points. When the multi-axis combined rotary table (1) is one-axis, two-axis or three-axis, one set of the laser emitter assembly (2), the holographic receiving screen (4) and the light spot collection and processing device (5) is arranged; when the multi-axis combined rotary table (1) is four-axis, five-axis or six-axis, two sets of the laser emitter assembly (2), the holographic receiving screen (4) and the light spot collection and processing device (5) are arranged.

2. The multi-axis gimballed table laser non-contact dynamic calibration system of claim 1, wherein, The spatial position measuring device (7) is a theodolite or a total station.

3. A calibration method for the multi-axis combined turntable laser non-contact dynamic calibration system of claim 2, characterized in that, The application further discloses a laser spot measurement method for a multi-axis combined rotary table (1), which comprises the following steps: S1: measuring spatial coordinates of three first target points on the holographic receiving screen (4) by using the spatial position measuring device (7), obtaining a plane equation of a plane where the holographic receiving screen (4) is located in a geodetic coordinate system A, and obtaining a homogeneous transformation matrix of a holographic receiving screen coordinate system M to the geodetic coordinate system A; S2: measuring the laser exit point of the laser transmitter assembly (2) installed on the multi-axis combined turntable (1) by using a spatial position measuring device (7) K Coordinates, obtaining the measured spot coordinates on the holographic receiving screen (4) by using a spot collection processing device (5) , combined with the homogeneous transformation matrix , obtaining the laser unit direction vector Coordinate representation in the geodetic coordinate system A , and determining the straight line equation where the laser is located; S3: obtaining the theoretical space intersection point coordinates of the plane where the holographic receiving screen (4) is located and the laser in the terrestrial coordinate system A before the multi-axis combined turntable (1) moves according to the plane equation of the plane where the holographic receiving screen (4) is located in the terrestrial coordinate system A obtained in step S1 and the straight line equation of the laser obtained in step S2 , calculating the system comprehensive error according to the theoretical space intersection point coordinates and the measured spot coordinates obtained in step S2 ; and ; S4: measuring two second target points of the multi-axis rotary table base by using the spatial position measuring device (7) to determine the homogeneous transformation matrix of the multi-axis rotary table base coordinate system B to the geodetic coordinate system A ; and simultaneously determining the homogeneous transformation matrix of the rotary table initial state coordinate system C to the geodetic coordinate system A ; specifically: S41: Before the multi-axis combination rotary table (1) moves, each axis is zeroed, two second target points are arranged on the multi-axis rotary table base, wherein the second target point Q close to the x-axis end direction of the terrestrial coordinate system A is taken as the origin of the multi-axis rotary table base coordinate system B, the space coordinates of the two second target points are measured, and the y-axis angle between the multi-axis rotary table base coordinate system B and the terrestrial coordinate system A is calculated Therefore, the homogeneous transformation matrix of the multi-axis rotary table base coordinate system B in the terrestrial coordinate system A is ​ ； In the formula, is the z-axis of the geodetic coordinate system A, and the angle of rotation around the z-axis is the included angle between the y-axis of the base coordinate system B of the multi-axis turntable and the geodetic coordinate system A ; are respectively the x-axis coordinate, the y-axis coordinate and the z-axis coordinate of the second target point Q in the geodetic coordinate system A. S42: The turntable initial state coordinate system C is obtained after the multi-axis turntable base coordinate system B is translated along the x-axis, y-axis and z-axis directions, and the homogeneous transformation matrix of the turntable initial state coordinate system C in the multi-axis turntable base coordinate system B is : ； In the formula, respectively, are three-axis offset amounts of the initial state coordinate system C of the rotary table obtained based on the base coordinate system B of the multi-axis rotary table along the x-axis, y-axis, and z-axis directions of the base coordinate system B. This information can be obtained by the multi-axis rotary table S2: obtaining a parameter manual of the combined rotary table (1); S43: the homogeneous transformation matrix of the multi-axis turntable base coordinate system B in the geodetic coordinate system A and the homogeneous transformation matrix of the turntable initial state coordinate system C in the multi-axis turntable base coordinate system B , the homogeneous transformation matrix of the turntable initial state coordinate system C to the geodetic coordinate system is determined ; ； S5: Obtain the laser unit direction vector in combination with steps S2 and S4 Coordinates in the initial state coordinate system C And the laser exit point K Coordinates in the initial state coordinate system C ; S6: constructing a plane equation of the plane where the holographic receiving screen is located during movement of the multi-axis combined rotary table (1); S7: Constructing the laser unit direction vector in the movement process of the multi-axis combined rotary table (1) and the laser exit point K in the coordinate system after the movement of the rotary table, obtaining the unit direction vector in the movement process of the multi-axis combined rotary table (1) and the laser exit point in the coordinate system A of the earth ; S8: According to steps S6 and S7, the intersection point coordinates of the theoretical motion space of the laser and the plane where the holographic receiving screen (4) is located in the earth coordinate system A during the movement of the multi-axis combined turntable (1) ; S9: using the light spot acquisition processing device (5) to acquire the measured motion light spot coordinates on the holographic receiving screen (4) in the motion process of the multi-axis combined rotary table (1) and converted into the geodetic coordinate system A; S10: the theoretical motion space intersection point coordinates obtained according to step S8 , eliminating the system comprehensive error obtained in step S3 , in combination with the measured motion spot coordinates obtained in step S9 , establishing an equation relationship between the theoretical motion space intersection point coordinates , the system comprehensive error , and the actual motion intersection point coordinates actually obtained by shooting , and solving the multi-degree-of-freedom motion parameters; S11: sending the solved multi-degree-of-freedom motion parameters to a multi-axis combined rotary table control system, calculating a closed-loop feedback correction value, and correcting control precision of the multi-axis combined rotary table (1).

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