A kinematic parameter identification method and system for a five-axis motion platform

Abstract

The present application discloses a method and system for identifying kinematic parameters of a five-axis motion platform, the method comprising: obtaining multiple photos taken by taking pictures of calibration plates located at different spatial positions; calibrating the internal parameters of the camera using the multiple photos; establishing a secondary coordinate relationship between an execution coordinate system and a workbench coordinate system, wherein the execution coordinate system is a camera coordinate system fixed on the first axis, and the workbench coordinate system is a calibration plate coordinate system on the second axis; solving the secondary coordinate pose matrix in the secondary coordinate relationship based on multiple photos taken by the camera at different positions after calibrating the internal parameters, and identifying the kinematic parameters of the five-axis motion platform. The present application solves the problem of high efficiency and low cost of kinematic calibration methods for five-axis motion platforms in the prior art, thereby improving the efficiency of kinematic calibration of five-axis motion platforms and reducing costs.

Description

Technical Field

[0001] The present application relates to the field of calibration, and in particular to a kinematic parameter identification method and system for a five-axis motion platform. Background Art

[0002] Currently, the kinematic calibration methods of five-axis motion platforms are mostly implemented using high-precision detection methods such as ballbars and laser interferometers. Although these calibration methods have high detection accuracy, they have problems such as low detection efficiency and high detection costs. Summary of the invention

[0003] The embodiments of the present application provide a kinematic parameter identification method and system for a five-axis motion platform, so as to at least solve the problem of high efficiency and low cost of kinematic calibration methods for five-axis motion platforms in the prior art.

[0004] According to one aspect of the present application, a method for identifying kinematic parameters of a five-axis motion platform is provided, including: obtaining a plurality of photos obtained by taking photos of a calibration plate located at different spatial positions, wherein a camera for taking the plurality of photos is arranged on a first axis among the five axes, and the calibration plate is arranged on a second axis among the five axes; calibrating internal parameters of the camera using the plurality of photos; establishing a secondary coordinate relationship between an execution coordinate system and a workbench coordinate system, wherein the execution coordinate system is a camera coordinate system fixed on the first axis, and the workbench coordinate system is a calibration plate coordinate system on the second axis; solving a secondary coordinate pose matrix in the secondary coordinate relationship according to a plurality of photos taken by the camera at different positions after calibrating the internal parameters, and identifying the kinematic parameters of the five-axis motion platform.

[0005] Furthermore, the five axes are X-axis, Y-axis, X-axis, A-axis and C-axis, wherein the A-axis and C-axis are rotation axes, the X-axis, Y-axis and Z-axis move in three-dimensional directions, the camera is set on the Z-axis, the calibration plate is set on the C-axis, the rotation axis of the A-axis is parallel to the Z-axis, and the rotation axis of the C-axis is parallel to the Z-axis.

[0006] Further, solving the secondary coordinate pose matrix in the secondary coordinate relationship to identify the kinematic parameters of the five-axis motion platform includes: solving the secondary coordinate pose matrix to first identify the direction parameters ω of the rotation axis a ,ω c , and then identify the position parameter q of the rotation axis a ,q c and the direction parameter v of the translation axis x 、v y 、v z .

[0007] Furthermore, establishing a secondary coordinate relationship between the execution coordinate system and the worktable coordinate system includes: establishing a forward kinematic model of the worktable coordinate system and the execution coordinate system based on an exponential product model, wherein the forward kinematic model is used to represent the secondary coordinate relationship between the execution coordinate system and the worktable coordinate system.

[0008] Furthermore, the camera is a monocular camera.

[0009] According to another aspect of the present application, a kinematic parameter identification system for a five-axis motion platform is also provided, including: an acquisition module, used to acquire multiple photos obtained by taking photos of a calibration plate located at different spatial positions, wherein the camera taking the multiple photos is set on the first axis of the five axes, and the calibration plate is set on the second axis of the five axes; a calibration module, used to calibrate the internal parameters of the camera using the multiple photos; an establishment module, used to establish a secondary coordinate relationship between an execution coordinate system and a workbench coordinate system, wherein the execution coordinate system is a camera coordinate system fixed on the first axis, and the workbench coordinate system is a calibration plate coordinate system on the second axis; an identification module, used to solve the secondary coordinate pose matrix in the secondary coordinate relationship according to the multiple photos taken by the camera at different positions after the internal parameters are calibrated, and identify the kinematic parameters of the five-axis motion platform.

[0010] Furthermore, the five axes are X-axis, Y-axis, X-axis, A-axis and C-axis, wherein the A-axis and C-axis are rotation axes, the X-axis, Y-axis and Z-axis move in three-dimensional directions, the camera is set on the Z-axis, the calibration plate is set on the C-axis, the rotation axis of the A-axis is parallel to the Z-axis, and the rotation axis of the C-axis is parallel to the Z-axis.

[0011] Furthermore, the identification module is used to solve the coordinate pose matrix and first identify the direction parameters ω of the rotation axis. a ,ω c , and then identify the position parameter q of the rotation axis a ,q c and the direction parameter v of the translation axis x , v y 、v z .

[0012] Furthermore, the establishment module is used to establish a forward kinematic model of the workbench coordinate system and the execution coordinate system based on an exponential product model, wherein the forward kinematic model is used to represent a secondary coordinate relationship between the execution coordinate system and the workbench coordinate system.

[0013] Furthermore, the camera is a monocular camera.

[0014] In an embodiment of the present application, a plurality of photos obtained by taking photos of a calibration plate located at different spatial positions are adopted, wherein the camera taking the plurality of photos is arranged on the first axis of the five axes, and the calibration plate is arranged on the second axis of the five axes; the internal parameters of the camera are calibrated using the plurality of photos; a secondary coordinate relationship between an execution coordinate system and a workbench coordinate system is established, wherein the execution coordinate system is a camera coordinate system fixed on the first axis, and the workbench coordinate system is a calibration plate coordinate system on the second axis; the secondary coordinate pose matrix in the secondary coordinate relationship is solved according to the plurality of photos taken by the camera at different positions after the internal parameters are calibrated, and the kinematic parameters of the five-axis motion platform are identified. The present application solves the problem of high efficiency and low cost of the kinematic calibration method of the five-axis motion platform in the prior art, thereby improving the efficiency of the kinematic calibration of the five-axis motion platform and reducing the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0016] Figure 1 is a flow chart of a kinematic parameter identification method of a five-axis motion platform according to an embodiment of the present application;

[0017] Figure 2 is a simplified structural diagram of a five-axis motion platform according to an embodiment of the present application;

[0018] Figure 3 This is a physical picture of a five-axis motion platform according to an embodiment of the present application. DETAILED DESCRIPTION

[0019] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0020] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0021] In this embodiment, a kinematic parameter identification method of a five-axis motion platform is provided. Figure 1 is a flow chart of a kinematic parameter identification method of a five-axis motion platform according to an embodiment of the present application. Figure 1 As shown, the process includes the following steps:

[0022] Step S102, obtaining a plurality of photos obtained by taking photos of the calibration plate located at different spatial positions, wherein the camera for taking the plurality of photos is arranged on a first axis among the five axes, and the calibration plate is arranged on a second axis among the five axes;

[0023] The first axis and the second axis can be in various situations. For example, the five axes are X-axis, Y-axis, X-axis, A-axis and C-axis, wherein the A-axis and C-axis are rotation axes, the X-axis, Y-axis and Z-axis move in three-dimensional directions, the camera is set on the Z-axis, the calibration plate is set on the C-axis, the rotation axis of the A-axis is parallel to, and the rotation axis of the C-axis is parallel to the Z-axis.

[0024] Step S104, calibrating the internal parameters of the camera using the multiple photos, optionally, the camera may be a monocular camera;

[0025] Step S106, establishing a secondary coordinate relationship between an execution coordinate system and a workbench coordinate system, wherein the execution coordinate system is a camera coordinate system fixed on the first axis, and the workbench coordinate system is a calibration plate coordinate system on the second axis;

[0026] In this step, a forward kinematics model of the workbench coordinate system and the execution coordinate system may be established based on an exponential product model, wherein the forward kinematics model is used to represent a secondary coordinate relationship between the execution coordinate system and the workbench coordinate system.

[0027] Step S108, solving the secondary coordinate pose matrix in the secondary coordinate relationship according to a plurality of photos taken by the camera at different positions after the internal parameters are calibrated, and identifying the kinematic parameters of the five-axis motion platform.

[0028] In this step, the coordinate pose matrix can be solved by the PnP algorithm. First, the direction parameters ω of the rotation axis are identified. a ,ω c , and then identify the position parameter q of the rotation axis a ,q c and the direction parameter v of the translation axis x 、v y 、v z .

[0029] The above steps solve the problem of high efficiency and low cost of the kinematic calibration method of the five-axis motion platform in the prior art, thereby improving the efficiency of the kinematic calibration of the five-axis motion platform and reducing the cost.

[0030] The following is an explanation in conjunction with an optional embodiment. This embodiment proposes a kinematic parameter identification method for a five-axis motion platform to solve the current research status of low efficiency, high cost and complex operation of the five-axis motion platform calibration. The method establishes a kinematic model of the five-axis motion platform through the screw theory and uses a monocular camera as a detection method to identify the parameters of the kinematic model.

[0031] In this embodiment, the forward kinematics model of the five-axis motion platform is established according to the structural characteristics of the five-axis motion platform, and the specific mathematical expression of the forward kinematics model is obtained; the specific mathematical expressions of rotational motion and translational motion are derived and simplified according to the screw theory, and the position parameters q of the two rotation axes in the forward kinematics model of the five-axis motion platform are a ,q c and the direction parameter ω a ,ω c And the direction parameters v of the three translation axes x 、v y 、v z Determine the kinematic parameters to be identified; a kinematic parameter identification method is proposed based on the detection method of a monocular camera. This method first identifies the direction parameters ω of the two rotation axes. a ,ω c , and then identify the position parameter q of the rotation axis a ,q c and the direction parameter v of the translation axis x 、v y 、v z .

[0032] The kinematic modeling of the five-axis motion platform in this embodiment is described below.

[0033] like Figure 2 As shown in the figure, the monocular camera is fixed on the Z axis, and the checkerboard calibration plate is fixed on the C axis. The movement of the X, Y and Z axes will change the position of the camera in space, and the rotation of the A and C axes will change the position of the checkerboard target in space. Multiple sets of photos can be taken in space using the movement of the X, Y, Z, A and C axes, and the internal parameters of the camera can be calibrated using the Zhang Zhengyou calibration method. Finally, the secondary coordinate position matrix of the calibration plate and the camera at any position can be solved using the PnP (Perspective-n-Point) algorithm.

[0034] According to the above monocular camera pose measurement method, the camera coordinate system fixed on the Z axis is used as the actuator coordinate system {A}, and the calibration plate coordinate system on the C axis is used as the workbench coordinate system {W}. In order to obtain the kinematic model from the actuator coordinate system {A} to the workbench coordinate system {W}, the secondary coordinate change relationship between the two coordinate systems is established. wRepresents the secondary coordinate pose matrix of the worktable coordinate system {W} relative to the actuator coordinate system {A}. Based on the exponential product model, the forward kinematic model of the worktable coordinate system {W} relative to the actuator coordinate system {A} is:

[0035]

[0036] in a g w (0) represents the initial pose matrix of the worktable coordinate system {W} relative to the actuator coordinate system {A}, ξ x ,ξ y ,ξ z ,ξ a and c They represent the rotary coordinates of the X, Y, Z, A and C axes in the actuator coordinate system {A} respectively; and Respectively represent the secondary coordinate matrices corresponding to the spinor coordinates; x, y, z, θ a and θ c Represents the movement of the X, Y, Z, A and C axes respectively.

[0037] Any spiral motion can be expressed as an exponent of a screw coordinate. Describing the motion of a rigid body, Taylor expansion of the exponent yields:

[0038]

[0039] in,

[0040]

[0041] In rotational motion, the spinor coordinates can be expressed as:

[0042]

[0043] Among them, ω represents the unit direction vector of the rotation axis, and p represents a point on the rotation axis.

[0044] Since ω is a unit vector, [ω] 3 =-ω is established. According to equation (2), the following relationship can be obtained:

[0045]

[0046] e [ω]θ =I 3×3 +[ω]sin(θ)+[ω] 2 (1-cos(θ)) (6)

[0047] Where θ represents the corresponding rotation amount.

[0048] When ||v||≠0, ω and v are orthogonal, so ω T v=0 exists; when ||v||=0, ω T v=0 still exists. Therefore, the following expression can be obtained:

[0049] ωω T vθ=0 1×3 (7)

[0050] Here, let q = ω × v, the geometric meaning of q is the foot point of the origin of the coordinate system with respect to the axis of the rotation axis. Therefore, q can represent the position parameter of the rotation axis in the spatial coordinate system, and ω represents the direction parameter of the rotation axis in the spatial coordinate system.

[0051] Therefore, equation (5) can be simplified as follows:

[0052]

[0053] In translational motion, the expression of the spinor coordinate ξ is:

[0054]

[0055] Among them, v represents the direction vector of the translation axis.

[0056] The matrix form of the translation axis motion is as follows:

[0057]

[0058] Therefore, the specific form of the forward kinematics model is as follows:

[0059]

[0060] in,

[0061]

[0062]

[0063] The following is an explanation of the kinematic parameter identification method of the five-axis motion platform of this embodiment.

[0064] Figure 3 This is a real picture of the five-axis motion platform. Based on the above monocular camera pose detection method, the secondary coordinate pose matrix of the worktable coordinate system {W} relative to the actuator coordinate system {A} a g w It can be easily obtained by taking an image of the target.

[0065] Equation (11) can be simplified as follows:

[0066]

[0067] in,

[0068]

[0069] Among them, the values ​​of ω1, ω2, θ1, θ2, q1, q2, v1, v2, and v3 are shown in Table 1.

[0070] Table 1 Parameters corresponding to symbols

[0071] symbol Parameter Value symbol Parameter Value <![CDATA[ω1]]> <![CDATA[ω a ]]> <![CDATA[q2]]> <![CDATA[q c ]]> <![CDATA[θ1]]> <![CDATA[θ a ]]> <![CDATA[v1]]> <![CDATA[v x ]]> <![CDATA[ω2]]> <![CDATA[ω c ]]> <![CDATA[v2]]> <![CDATA[v y ]]> <![CDATA[θ2]]> <![CDATA[θ c ]]> <![CDATA[v3]]> <![CDATA[v z ]]> <![CDATA[q1]]> <![CDATA[q a ]]>

[0072] According to equation (6), the 3×3 matrix R in equation (15) 3×3 There are the following expressions:

[0073]

[0074] Among them, the values ​​of W1, W2, W3, W4, W5, W6, W7, W8, and W9 are shown in Table 2.

[0075] Table 2 Values ​​corresponding to matrix symbols

[0076] Matrix Notation value Matrix Notation value <![CDATA[W1]]> <![CDATA[I 3×3 ]]> <![CDATA[W6]]> <![CDATA[[ω1] 2 [ω2]]> <![CDATA[W2]]> <![CDATA[[ω1]]]> <![CDATA[W7]]> <![CDATA[[ω2] 2 ]]> <![CDATA[W3]]> <![CDATA[[ω2] 2 ]]> <![CDATA[W8]]> <![CDATA[[ω1][ω2] 2 ]]> <![CDATA[W4]]> <![CDATA[[ω2]]]> <![CDATA[W9]]> <![CDATA[[ω1] 2 [ω2] 2 ]]> <![CDATA[W5]]> <![CDATA[[ω1][ω2]]]>

[0077] According to equation (14), the following expression is obtained:

[0078]

[0079] in, a g w Represents the position matrix of the platform with the motion of (x,y,z,θ1,θ2) on the X,Y,Z,A and C axes; a g w (0) represents the initial pose matrix when the X, Y, Z, A and C axes are at their initial positions.

[0080] make a G w =( a g w )( a g w (0)) -1 , so the following expression can be obtained:

[0081]

[0082] Among them, the pose matrix a g w and a g w(0) can be obtained by a monocular camera, so a G w It can also be obtained simply.

[0083] For the matrix a G w The 3×3 matrix R in 3×3 , can be obtained by equation (16). For any i∈{1,2,3} and j∈{1,2,3}, The matrix R can be obtained. 3×3 Each element in can find a corresponding expression, such as the element a G w The first row and column element in a G w (1,1) (Also ) has the following expressions:

[0084] W (1,1) =[W1 (1,1) W2 (1,1) W3 (1,1) W4 (1,1) W5 (1,1) W6 (1,1) W7 (1,1) W8 (1,1) W9 (1,1) ] T (19)

[0085]

[0086] therefore, a G w (1,1) Can be obtained:

[0087] a G w (1,1) =θ1 T W (1,1) (twenty one)

[0088] In fact, for any i∈{1,2,3} and j∈{1,2,3}, we have the following expressions:

[0089]

[0090] When the five-axis motion platform is moved to multiple different positions, any position a G w (i,j) The value of can be detected by the monocular camera a g w (0) and a gw , Θ1 is the known motor motion. Equation (22) is a linear system of equations, so the least squares method can be used to solve multiple groups of a G w (i,j) and Θ1 to solve for W (i,j) Finally, using the expressions of equation (23) and equation (24), we can solve ω1 and ω2 according to the matrix W2 and matrix W4 in Table 2.

[0091]

[0092]

[0093] According to equation (23), the matrix W2 has the following expression:

[0094] W2 (2,1) =-W2 (1,2) =ω1 (z) (25)

[0095] However, the value of W2 is obtained by the least squares method, equation W2 (2,1) =-W2 (1,2) is not necessarily true. Therefore, when calculating ω1 (z) It can be calculated by the following equation:

[0096] ω1 (z) =(W2 (2,1) -W2 (1,2) ) / 2 (26)

[0097] ω1 (x) ,ω1 (y) ,ω2 (x) ,ω2 (y) and ω2 (z) It can also be calculated in the same way as above. Therefore, the direction vector of the rotation axis can be obtained by the equation ω1 = [ω1 (x) ω1 (y) ω1 (z) ] T ,ω2=[ω2 (x) ω2 (y) ω2 (z) ] T Please solve.

[0098] For the vector p in equation (18) 3×1 It can be written as follows:

[0099] p 3×1 =Ω1q1+Ω2q2+W 10 [xyz] T (27)

[0100] Among them, the vector vector Ω1, Ω2 and W 10 The values ​​are shown in Table 3.

[0101] Table 3 Ω1, Ω2 and W 10 Value

[0102]

[0103] Likewise, the vector p 3×1 Each element in has a corresponding expression. 3×1 The first element p in (1) 3×1 For example, there is the following expression:

[0104] p (1) 3×1 =Ψ1Φ (1) (28)

[0105] in,

[0106] Ψ1=[Ω1 (1,1) Ω1 (1,2) Ω1 (1,3) Ω2 (1,1) Ω2 (1,2) Ω2 (1,3) xyz] (29)

[0107]

[0108] For p (2) 3×1 and p (3) 3×1 , which has the following expressions:

[0109] p (2) 3×1 =Ψ2Φ (2) (31)

[0110] p (3) 3×1 =Ψ3Φ (3) (32)

[0111] in,

[0112] Ψ2=[Ω1 (2,1) Ω1 (2,2) Ω1 (2,3) Ω2 (2,1) Ω2 (2,2) Ω2 (2,3) xyz] (33)

[0113] Ψ3=[Ω1 (3,1) Ω1 (3,2) Ω1 (3,3) Ω2 (3,1) Ω2 (3,2) Ω2 (3,3) xyz] (34)

[0114]

[0115]

[0116] As mentioned above, ω1 and ω2 have been obtained by solving the method for the direction of the rotation axis. Substitute the values ​​of ω1 and ω2 into the expressions of Ω1 and Ω2 in Table 3, and the values ​​of θ1, θ2, x, y and z are known motion quantities. Therefore, taking equation (28) as an example, for the five-axis motion platform at any position, p (1) 3×1 and Ψ1. can be easily obtained. Equation (28) is a linear equation system, so through multiple sets of p at different positions (1) 3×1 and Ψ1, and use the least squares method to solve Φ (1) Similarly, using equations (31) and (32) to solve Φ (2) and Φ (3) value.

[0117] For, vector At the same time, we can use the vector Φ (1) ,Φ (2) and Φ (3) However, through Φ (1) ,Φ (2) and Φ (3) The q1 solved may not be completely consistent. Therefore, in order to find a unique value of q1, Φ can be obtained. (1) ,Φ (2) and Φ (3) The average of the three q1s is used as the unique value. The solution of vector q2 is the same. Finally, due to Therefore, v1, v2 and v3 can be expressed by their components in Φ (1) ,Φ (2) and Φ (3) to calculate the value of .

[0118] In summary, the detection method of the monocular camera can be used according to the above algorithm to complete the kinematic parameter identification of the five-axis motion platform, including the direction parameters ω of the two rotation axes. a ,ω c and position parameter q a ,q c And the direction parameters v of the three translation axesx 、v y and v z .

[0119] In this embodiment, an electronic device is provided, including a memory and a processor. The memory stores a computer program, and the processor is configured to run the computer program to execute the method in the above embodiment.

[0120] The above program can be run in a processor, or can also be stored in a memory (or referred to as a computer-readable medium), which includes permanent and non-permanent, removable and non-removable media, and can be implemented by any method or technology to store information. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, read-only compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. According to the definition in this embodiment, computer-readable media does not include temporary computer-readable media (transitory media), such as modulated data signals and carriers.

[0121] These computer programs can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps of the functions specified in one or more blocks can be implemented by different modules corresponding to different steps.

[0122] Such a device or system is provided in this embodiment. The system is called a kinematic parameter identification system for a five-axis motion platform, and includes: an acquisition module for acquiring multiple photos taken by taking pictures of a calibration plate located at different spatial positions, wherein the camera taking the multiple photos is set on the first axis of the five axes, and the calibration plate is set on the second axis of the five axes; a calibration module for calibrating the internal parameters of the camera using the multiple photos; an establishment module for establishing a secondary coordinate relationship between an execution coordinate system and a workbench coordinate system, wherein the execution coordinate system is a camera coordinate system fixed on the first axis, and the workbench coordinate system is a calibration plate coordinate system on the second axis; an identification module for solving the secondary coordinate pose matrix in the secondary coordinate relationship according to multiple photos taken by the camera at different positions after calibrating the internal parameters, and identifying the kinematic parameters of the five-axis motion platform.

[0123] The system or device is used to implement the functions of the method in the above-mentioned embodiment. Each module in the system or device corresponds to each step in the method, which has been explained in the method and will not be repeated here.

[0124] For example, the identification module is used to solve the coordinate pose matrix and first identify the direction parameters ω of the rotation axis. a ,ω c , and then identify the position parameter q of the rotation axis a ,q c and the direction parameter v of the translation axis x 、v y 、v z .

[0125] For another example, the establishment module is used to establish a forward kinematic model of the workbench coordinate system and the execution coordinate system based on an exponential product model, wherein the forward kinematic model is used to represent a secondary coordinate relationship between the execution coordinate system and the workbench coordinate system.

[0126] The solution provided by the above embodiment is based on spiral theory and monocular vision, and realizes low-cost and high-efficiency kinematic parameter identification.

[0127] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A kinematic parameter identification method for a five-axis motion platform, characterized in that: include: Acquire a plurality of photos obtained by taking photos of the calibration plate located at different spatial positions, wherein a camera for taking the plurality of photos is arranged on a first axis among the five axes, and the calibration plate is arranged on a second axis among the five axes; Using the multiple photos to calibrate the internal parameters of the camera; Establishing a secondary coordinate relationship between an execution coordinate system and a workbench coordinate system, wherein the execution coordinate system is a camera coordinate system fixed on the first axis, and the workbench coordinate system is a calibration plate coordinate system on the second axis; The secondary coordinate pose matrix in the secondary coordinate relationship is solved based on a plurality of photos taken by the camera at different positions after the internal parameters are calibrated, and the kinematic parameters of the five-axis motion platform are identified.

2. The method according to claim 1, characterized in that The five axes are X-axis, Y-axis, Z-axis, A-axis and C-axis, wherein the A-axis and C-axis are rotation axes, the X-axis, Y-axis and Z-axis move in three-dimensional directions, the camera is set on the Z-axis, the calibration plate is set on the C-axis, the rotation axis of the A-axis is parallel to the Z-axis, and the rotation axis of the C-axis is parallel to the Z-axis.

3. The method according to claim 2, characterized in that Solving the secondary coordinate pose matrix in the secondary coordinate relationship and identifying the kinematic parameters of the five-axis motion platform include: To solve the coordinate pose matrix, first identify the direction parameters ω of the rotation axis. a ,ω c , and then identify the position parameter q of the rotation axis a ,q c and the direction parameter v of the translation axis x 、v y 、v z .

4. The method according to claim 2, characterized in that: The secondary coordinate relationship between the execution coordinate system and the workbench coordinate system is established including: Based on the exponential product model, a forward kinematics model of the workbench coordinate system and the execution coordinate system is established, wherein the forward kinematics model is used to represent the secondary coordinate relationship between the execution coordinate system and the workbench coordinate system.

5. The method according to any one of claims 1 to 4, characterized in that The camera is a monocular camera.

6. A kinematic parameter identification system for a five-axis motion platform, characterized in that: include: an acquisition module, used to acquire a plurality of photos obtained by taking photos of the calibration plate located at different spatial positions, wherein the camera for taking the plurality of photos is arranged on a first axis among the five axes, and the calibration plate is arranged on a second axis among the five axes; A calibration module, used to calibrate the internal parameters of the camera using the multiple photos; An establishing module, used to establish a secondary coordinate relationship between an execution coordinate system and a workbench coordinate system, wherein the execution coordinate system is a camera coordinate system fixed on the first axis, and the workbench coordinate system is a calibration plate coordinate system on the second axis; The identification module is used to solve the secondary coordinate pose matrix in the secondary coordinate relationship according to a plurality of photos taken by the camera at different positions after the internal parameters are calibrated, and identify the kinematic parameters of the five-axis motion platform.

7. The system according to claim 6, characterized in that The five axes are X-axis, Y-axis, Z-axis, A-axis and C-axis, wherein the A-axis and C-axis are rotation axes, the X-axis, Y-axis and Z-axis move in three-dimensional directions, the camera is set on the Z-axis, the calibration plate is set on the C-axis, the rotation axis of the A-axis is parallel to the Z-axis, and the rotation axis of the C-axis is parallel to the Z-axis.

8. The system according to claim 7, characterized in that The identification module is used for: To solve the coordinate pose matrix, first identify the direction parameters ω of the rotation axis. a ,ω c , and then identify the position parameter q of the rotation axis a ,q c and the direction parameter v of the translation axis x 、v y 、v z .

9. The system according to claim 7, characterized in that The establishment module is used to: Based on the exponential product model, a forward kinematics model of the workbench coordinate system and the execution coordinate system is established, wherein the forward kinematics model is used to represent the secondary coordinate relationship between the execution coordinate system and the workbench coordinate system.

10. The system according to any one of claims 6 to 9, characterized in that The camera is a monocular camera.

Images