System and method for testing transmission precision of driving joint for space manipulator

Abstract

The invention discloses a driving joint transmission precision test system and method for a space manipulator, and belongs to the technical field of space manipulators. The multi-stage speed reduction driving joint is divided into single-stage speed reduction, the transmission precision of each stage is tested at a time, and then the transmission precision of the whole machine is summarized according to the transmission ratio. Required measurement equipment, namely the rotation angle measurement device, is simple to operate and has relatively good universality; laser is used for measuring the transmission precision of a planetary reducer, a 24-face prism and a cross light standard collimator are used for measuring the transmission precision of a harmonic reducer, and then high-precision and high-efficiency testing of the transmission precision of the driving joint for the space manipulator is achieved.

Description

Technical Field

[0001] The invention relates to a driving joint transmission accuracy testing system and method for a space robot arm, belonging to the technical field of space robot arms. Background Art

[0002] With the increasing number of multi-field missions such as deep space exploration, communication navigation, and earth observation, the number of space manipulator motion drive joint mechanisms in various payload subsystems of spacecraft has increased dramatically. This type of drive joint mechanism has high positioning accuracy, large transmission ratio, and strong load-bearing capacity. Its technical indicators have high requirements on the accuracy and efficiency of assembly and performance test methods. Among them, the transmission accuracy characteristic is an important technical indicator of high-precision and high-transmission ratio multi-stage reducer drive joint mechanism. Accurate and efficient measurement and calibration can improve the output accuracy of the drive joint itself and the positioning accuracy of the end load of the manipulator. At present, the transmission accuracy index of the drive joint can be obtained by establishing the part size deviation and reducer transmission error model, and using simulation and calculation methods to obtain the transmission accuracy of the joint. However, due to factors such as component machining size measurement error, assembly clearance, and deviation of the transmission accuracy theoretical model, the transmission accuracy obtained by the theoretical calculation method deviates from the actual value. Therefore, it is necessary to take the multi-stage reducer drive joint as the test object and propose a drive joint transmission accuracy test method for space manipulators.

[0003] The driving joint mechanism for space manipulators has the characteristics of high precision and large load, and is usually composed of a multi-stage reducer and an output shaft system. The reducers of this type of driving joint are mostly planetary reducers or spur gear pairs and harmonic reducers in series in a multi-stage series structure: the planetary reducer / spur gear pair has a relatively small number of teeth, a small transmission ratio, a large tooth gap, and poor transmission accuracy; the harmonic reducer has a relatively large number of teeth, a large transmission ratio, a small tooth gap, and a high transmission accuracy. The transmission accuracy of the above two types of reducers requires measuring the actual rotation angle of the input and output ends of the reducer, and calculating the transmission accuracy of the corresponding measuring points with the theoretical rotation angle. Based on a high-precision drive mechanism test bench, supplemented by a new output angle measurement module, a driving joint transmission accuracy test system for space manipulators was constructed, and a driving joint transmission accuracy test method for space manipulators was proposed, which has become an effective means to solve the problem of efficient and accurate measurement of the transmission accuracy of the above driving joints. Summary of the invention

[0004] The technical problem solved by the present invention is: to overcome the deficiencies of the prior art and provide a system and method for testing the transmission accuracy of a driving joint for a space manipulator, thereby achieving high-precision and high-efficiency testing of the transmission accuracy of a driving joint for a space manipulator.

[0005] The technical solution of the present invention is: a driving joint transmission accuracy test system for a space manipulator, comprising:

[0006] The planetary reducer test module comprises a first-stage driving joint mechanism precision test bench, a planetary reducer assembly of the driving joint, and an output angle measurement module of the planetary reducer assembly; a guide rail is fixedly installed on the first-stage driving joint mechanism precision test bench, and a servo motor, a coupling, a circular grating, and a product bracket are sequentially installed on the guide rail; the planetary reducer assembly is connected to the product bracket through its own mounting stop; the circular grating is used to measure the input end angle of the planetary reducer assembly, the servo motor is used to drive the planetary reducer assembly of the driving joint to rotate to each transmission precision measurement point, and the coupling is used to connect the servo motor and the circular grating; the planetary reducer output angle measurement module is a laser tracker angle measurement system, which is placed on the side of the first-stage driving joint mechanism precision test bench, and is used to convert the point position information of the laser target ball at different measuring points into the actual output angle of each measuring point of the planetary reducer assembly through homogeneous transformation;

[0007] A harmonic reducer test module comprises a second-stage driving joint mechanism precision test bench, a harmonic reducer assembly of a driving joint, and an output angle measurement module of the harmonic reducer assembly; a guide rail is fixedly installed on the second-stage driving joint mechanism precision test bench, and a servo motor, a coupling, a circular grating, and a product bracket are sequentially installed on the guide rail; the harmonic reducer assembly is connected to the product bracket through its own mounting stop; the circular grating is used to measure the input end angle of the harmonic reducer assembly, the servo motor is used to drive the measured joint to rotate to each transmission precision measurement point, and the coupling is used to connect the servo motor and the circular grating; the harmonic reducer output angle measurement module comprises a prism and a collimator, the prism is installed on the output end test adapter shaft of the harmonic reducer assembly, the collimator is installed at the output end angle test bracket, the output end angle is a fixed value, the collimator captures the prism normal feedback signal until the servo motor stops rotating, and obtains the actual input end angle of the harmonic reducer assembly through the circular grating.

[0008] A method for testing the transmission accuracy of a driving joint of a space manipulator implemented by the driving joint transmission accuracy testing system for a space manipulator, comprising a planetary reducer assembly transmission accuracy test, a harmonic reducer assembly transmission accuracy test and calculation of the transmission accuracy of the driving joint as a whole;

[0009] The transmission accuracy test of the planetary reducer assembly includes:

[0010] S11, perform kinematic calibration of the coordinate system of the output shaft of the planetary reducer joint, and obtain the world coordinate system {i 世界} and the output coordinate system {i 输出端}'s pose relationship matrix T 输出端-世界 ;

[0011] S12, driving the input end of the planetary reducer assembly to rotate to each measuring point through the servo motor of the first-stage driving joint mechanism precision test bench;

[0012] S13, according to the posture relationship matrix T 输出端-世界 Calculate the difference between the theoretical rotation angle and the actual rotation angle of the output end of the planetary reducer at each measuring point as the transmission accuracy of the planetary reducer assembly;

[0013] The transmission accuracy test of the harmonic reducer assembly includes:

[0014] S21, driving the input end of the harmonic reducer assembly to rotate through the servo motor of the second-stage driving joint mechanism precision test bench;

[0015] S22, the input end rotation angle of the harmonic reducer assembly is reset to zero, and the prism normal of the output end of the harmonic reducer assembly is continued to rotate in the same direction until the prism normal of the output end of the harmonic reducer assembly is perpendicular to the collimator plane, and the servo motor of the second-stage driving joint mechanism precision test bench is fed back to stop rotating, and the actual input end rotation angle is obtained through the circular grating of the second-stage driving joint mechanism precision test bench;

[0016] S23, repeating S21 and S22, obtaining the actual rotation angle of the input end when the output end of the harmonic reducer assembly rotates until each surface of the prism is perpendicular to the collimator plane;

[0017] S24, calculating the difference between the theoretical rotation angle of the output end of each measuring point of the harmonic reducer assembly and the actual rotation angle of the output end as the transmission accuracy of the harmonic reducer assembly;

[0018] The calculation of the transmission accuracy of the driving joint includes:

[0019] The transmission accuracy of the driving joint for the space robot arm is calculated based on the transmission accuracy of the planetary reducer assembly and the transmission accuracy of the harmonic reducer assembly.

[0020] Furthermore, the transmission accuracy of the planetary reducer assembly is ε 行星 =θ 输入行星 / i 行星 -θ 输出行星 ; where θ 输入行星 The servo motor of the first-level driving joint mechanism precision test bench drives the input end of the planetary reducer assembly to rotate between adjacent measuring points, i 行星 is the transmission ratio of the planetary reducer assembly to be tested, θ 输出行星 It is the angle between the lines connecting adjacent points and the coordinate origin.

[0021] Furthermore, the input end of the planetary reducer assembly rotates θ 输入行星 After the angle is measured, the laser tracker angle measurement system is used to measure the output end laser target ball in the world coordinate system {i 世界 Spatial position P 世界 =[P 1世界 P 2世界 … Pn世界 ] T ; Through the pose transformation matrix T 输出端-世界 Get the laser target ball in the coordinate system {i 输出端 The spatial position P of 输出端 =[P 1输出端 P 2输出端 … P n输出端 ] T ; Taking the coordinate system of the output end of the planetary reducer assembly {i 输出端} is used as a reference, and the angle between the adjacent points and the coordinate origin is the actual rotation angle θ at the output end of the planetary reducer assembly. 输出行星 =[θ 1输出 θ 2输出 … θ n输出 ] T ; Calculate the transmission accuracy of the planetary reducer assembly, which is the difference between the theoretical rotation angle and the actual rotation angle at the output end of the planetary reducer assembly.

[0022] Furthermore, the transmission accuracy of the harmonic reducer assembly is ε 谐波 =θ 输入谐波 / i 谐波 -θ 输出谐波 ; where θ 输入谐波 is the actual rotation angle of the input end when the output end of the harmonic reducer assembly is rotated to the point where the prism faces are perpendicular to the collimator plane, i 谐波 is the transmission ratio of the harmonic reducer, θ 输出谐波 It is the actual rotation angle of the input end when the output end of the harmonic reducer assembly rotates to each face of the prism.

[0023] Furthermore, the transmission accuracy of the driving joint of the space manipulator is ε 关节 =ε 行星 / i 谐波 +ε 谐波 ; Among them, ε 行星 is the transmission accuracy of the planetary reducer assembly, i 谐波 is the transmission ratio of the harmonic reducer assembly, ε 谐波 Transmission accuracy of harmonic reducer assembly.

[0024] Furthermore, the driving joint is a multi-stage reducer series structure.

[0025] Furthermore, the planetary reducer assembly and the harmonic reducer assembly are measured using a laser tracker, a collimator and a prism respectively.

[0026] The advantages of the present invention compared with the prior art are:

[0027] (1) The method of the present invention decomposes the multi-stage reduction structure drive joint into a single-stage reduction, and adopts a method of testing the transmission accuracy of the single-stage reducer separately. Compared with the direct test of the general assembly, the number of rotations of the drive joint is less, the operation is simple, and the test efficiency can be improved, and the scientific research and production efficiency can be improved. It has good general practicality; it can also reduce the loss of moving parts (such as bearings and gears), and can extend the on-orbit service life of the model product.

[0028] (2) The method of the present invention measures the transmission accuracy in stages. Since the transmission error of the planetary reducer is relatively large, it is difficult to measure the output angle with prism resolution. The measurement accuracy can be improved by using a laser tracker angle measurement system. At the same time, the staged measurement can intuitively reflect the assembly status of each stage and provide a reference for the adjustment of the drive joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0030] Figure 1 It is a schematic diagram of the structure of the driving joint for the space manipulator of the present invention;

[0031] Figure 2 It is a schematic flow chart of the testing method of the present invention;

[0032] Figure 3 This is a schematic diagram of the planetary reducer test module;

[0033] Figure 4 This is a schematic diagram of the harmonic reducer test module. DETAILED DESCRIPTION

[0034] In order to better understand the above technical scheme, the technical scheme of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical scheme of the present invention, rather than limitations on the technical scheme of the present invention. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0035] The following is a further detailed description of a driving joint transmission accuracy testing system and method for a space manipulator provided by an embodiment of the present invention in conjunction with the accompanying drawings of the specification. The specific implementation method may include:

[0036] The object to be tested in the present invention is a driving joint of a multi-stage reducer structure, and its structural form is as follows Figure 1The present invention takes the driving joint of a first-stage planetary reducer connected in series with a first-stage harmonic reducer as the object of explanation, and describes the transmission accuracy test method of the driving joint of the space manipulator. Figure 2 .

[0037] First, the multi-stage reducer structure drive joint is split into a single-stage reducer transmission structure, that is, it is disconnected from the planetary carrier and the harmonic wave generator, and is divided into a planetary reducer assembly and a harmonic reducer assembly. The input end of the planetary reducer assembly is assembled with a simulated motor for testing, the input end of the simulated motor is a test bench interface, and the output end of the simulated motor is connected to the sun gear of the planetary reducer; the output end of the planetary reducer assembly is assembled with a precision test flange for testing the actual rotation angle of the output end. The input end of the harmonic reducer assembly is assembled with a simulated motor for testing, the input end of the simulated motor is a test bench interface, and the output end of the simulated motor is connected to the wave generator of the harmonic reducer assembly; the output end of the harmonic reducer assembly is assembled with a precision test adapter shaft for testing the actual rotation angle of the output end.

[0038] Secondly, build a drive joint transmission accuracy test system for space manipulators, such as Figure 3 , Figure 4 . It includes a planetary reducer assembly transmission accuracy test module and a harmonic reducer assembly transmission accuracy test module. The planetary reducer assembly transmission accuracy test module consists of a planetary reducer assembly accuracy test bench, a planetary reducer assembly, and a planetary reducer output angle measurement module. The servo motor, coupling, circular grating, and product bracket are installed on the guide rail of the planetary reducer assembly accuracy test bench in sequence; the planetary reducer assembly is connected to the product bracket of the accuracy test bench through the mounting stop of the product itself; the planetary reducer assembly output angle measurement module is a laser tracker angle measurement system, which can convert the position information of the laser target ball at different measuring points into the actual angle of the output end of each measuring point through homogeneous transformation. The harmonic reducer assembly transmission accuracy test module consists of a harmonic reducer assembly accuracy test bench, a harmonic reducer assembly, and a harmonic reducer output angle measurement module. The composition and layout of the harmonic reducer assembly precision test bench are the same as those of the planetary reducer assembly precision test bench. The harmonic reducer assembly output angle measurement module consists of a prism and a collimator. The prism is installed on the test adapter shaft at the output end of the harmonic reducer assembly, and the collimator is installed on the precision test bench to feedback the rotation angle of the output end of the harmonic reducer assembly.

[0039] Next, perform the transmission accuracy test of the planetary reducer assembly. The output angle coordinate system needs to be kinematically calibrated to establish the world coordinate system of the laser tracker angle measurement system {i 世界} and the coordinate system of the output end of the planetary reducer {i 输出端}, the purpose is to obtain the posture transformation matrix T 输出端-世界 , T 输出端-世界 is a 4x4 square matrix, formula (1):

[0040]

[0041] Among them, R 3×3 H represents the rotation matrix. 3×1 Represents the translation vector. The servo motor of the precision test bench rotates the reducer input end multiple times, and the circular grating is used to measure the rotation angle θ of the planetary reducer input end 输入行星 =[θ 1输入 θ 2输入 … θ n输入 ] T The laser target ball of the laser tracker angle measurement system is installed on the output end precision test flange to measure the spatial position P of the output end laser target ball in the world coordinate system corresponding to each input angle. 世界 =[P 1世界 P 2世界 … P n世界 ] T , through the pose transformation matrix T 输出端-世界 The target ball can be placed in the coordinate system {i 世界} is converted into the coordinate system {i 输出端 The spatial position P of 输出端 =[P 1输出端 P 2输出端 … P n输出端 ] T , that is, to obtain the output angle θ corresponding to each input angle 输出行星 =[θ 1输出 θ 2输出 … θ n输出 ] T Therefore, the transmission accuracy of the planetary reducer assembly is the theoretical rotation angle θ at the output end of the planetary reducer assembly. 输出行星理论 The actual rotation angle θ at the output 输出行星实际 The difference:

[0042] ε 行星 =θ 输出行星理论 -θ 输出行星实际 =θ 输入行星 / i 行星 -θ 输出行星 (2)

[0043] Among them, i 行星 is the transmission ratio of the planetary reducer assembly.

[0044] Next, perform the transmission accuracy test of the harmonic reducer assembly. The servo motor of the harmonic reducer assembly accuracy test bench drives the input end of the harmonic reducer assembly to rotate at a low speed near each measuring point, and the output end of the harmonic reducer assembly is fixedly connected to the prism. When the output end rotates until the normal of the prism plane is perpendicular to the collimator plane (that is, the prism cross cursor coincides with the collimator cross cursor), the servo motor of the accuracy test bench stops rotating, and the actual rotation angle θ of the input end is read through the circular grating at the reducer input end. 输入1 The servo motor at the input end continues to rotate until the normals of the remaining prism surfaces of the output prism are perpendicular to the collimator plane, and the actual rotation angle θ of the input end is read in sequence through the circular grating at the input end 输入谐波 =[θ 输入1 θ 输入2 … θ 输入n ] T Therefore, the transmission accuracy of the harmonic reducer assembly is the theoretical rotation angle θ at the output end of the harmonic reducer assembly. 输出谐波理论 The actual rotation angle θ at the output 输出谐波实际 The difference:

[0045] ε 谐波 =θ 输出谐波理论 -θ 输出谐波实际 =θ 输入谐波 / i 谐波 -θ 输出谐波 (3)

[0046] Among them, i 谐波 is the transmission ratio of the harmonic reducer assembly.

[0047] Finally, a calculation model for the transmission accuracy of the driving joint of the space manipulator is established, and the transmission accuracy of the first-stage planetary reducer assembly is converted to the input end of the second-stage harmonic reducer assembly, ε 关节 =ε 行星 / i 谐波 +ε 谐波 , calculate and obtain the transmission accuracy of each measuring point of the driving joint.

[0048] In the solution provided in the embodiment of the present invention, combined with Figure 2 , a detailed application description of a method for testing the transmission accuracy of a driving joint for a space manipulator is given:

[0049] The first step is to disassemble the multi-stage transmission reduction drive joint of the space robot arm to be tested into a single-stage transmission reduction reducer mechanism. The present invention takes the driving joint of the first-stage planetary reducer assembly and the second-stage harmonic reducer assembly in series as an example to illustrate its structural form. Figure 1As shown. The output end of the first-stage transmission planetary reducer assembly is the planet carrier, and the input end of the second-stage transmission harmonic reducer assembly is the harmonic wave generator. Remove the connecting fasteners between the planet carrier and the wave generator; install a test simulation motor at the input end of the first-stage planetary reducer assembly, and install a precision test flange at the output end of the planet carrier; install a test simulation motor at the input end of the second-stage harmonic reducer assembly, and install a precision test adapter shaft at the output end.

[0050] The second step is to build a drive joint transmission accuracy test system for space manipulators. The joint transmission system is divided into a planetary reducer assembly transmission accuracy test module and a harmonic reducer assembly transmission accuracy test module, such as Figure 3 As shown. Both are composed of a precision test bench, a reducer assembly, and an output angle measurement module. The drive joint mechanism precision test bench is a marble platform, on which a linear guide rail is fixedly installed. The drive joint mounting bracket is fixedly installed on the guide rail by screws, and the planetary reducer assembly / harmonic reducer assembly is installed to the bracket through the mounting stop; the input end of the planetary reducer assembly / harmonic reducer assembly is connected to the circular grating and the servo motor in turn. The circular grating is used to measure the input end angle, and the servo motor is used to drive the measured joint to rotate to each transmission precision measurement point. The output angle measurement module of the transmission accuracy test module of the planetary reducer assembly is a laser tracker measurement system. A laser target ball is pasted on the accuracy test flange at the output end of the planetary reducer assembly, and a laser tracker is used to measure the actual output angle corresponding to each measuring point; the output angle measurement module of the harmonic reducer assembly transmission accuracy test module is a prism and collimator system. The joint output end is directly connected to the prism, and the collimator is fixed to the output end angle test bracket. The output end angle is a fixed value. The collimator captures the prism normal feedback signal until the servo motor stops rotating, and the actual input end angle is obtained through the circular grating.

[0051] The third step is to perform the transmission accuracy test of the planetary reducer assembly. First, the kinematic calibration of the output shaft coordinate system of the planetary reducer assembly is carried out. The purpose is to calibrate the output shaft laser target ball point of each measuring point in the laser tracker world coordinate system {i 世界}, the output angle is measured in the output end coordinate system {i 输出端} to solve, so it is necessary to obtain the laser tracker world coordinate system {i 世界} and the output coordinate system {i 输出端}'s pose relationship matrix T 输出端-世界 The laser target ball is bonded to the precision test flange at the output end of the joint. There is no unique method for defining the output shaft coordinate system. The coordinate system definition rule in the present invention is: the output shaft rotates one circle, and the circular plane is fitted using the laser target ball point information. The normal direction of this plane is the z direction of the output shaft coordinate system, the center of the circular plane is the origin of the coordinate system, the y direction of the coordinate system is defined as the normal direction of the precision test bench, and the x-axis direction of the coordinate system is determined according to the right-hand rule; according to the above method, the coordinate system {i 输出端} kinematic calibration, the pose relationship matrix T can be obtained in the Spatial Analyzer software 输出端-世界 .

[0052] Secondly, the servo motor of the precision test bench drives the input end of the planetary reducer assembly to rotate to each measuring point. Generally, the transmission accuracy measuring points of the planetary reducer assembly are divided into n equal parts of the output end circumference. Therefore, the input end servo motor needs to drive the input end of the planetary reducer assembly to rotate by an angle θ between adjacent measuring points. 输入行星 for:

[0053]

[0054] Again, the input terminal rotates θ 输入行星 After the angle is measured, the laser tracker measurement system is used to measure the output end laser target ball in the world coordinate system {i 世界 Spatial position P 世界 =[P 1世界 P 2世界 … P n世界 ] T ; Through the pose transformation matrix T 输出端-世界 The laser target ball can be obtained in the coordinate system {i 输出端 The spatial position P of 输出端 =[P 1输出端 P 2输出端 … P n输出端 ] T ; Based on the output coordinate system {i 输出端} is used as a reference, and the angle between the adjacent points and the coordinate origin is the actual rotation angle θ of the output end. 输出行星 =[θ 1输出 θ 2输出 … θ n输出 ] T Finally, the transmission accuracy of the planetary reducer is calculated as the theoretical rotation angle θ at the output end of the planetary reducer assembly. 输出行星理论 The actual rotation angle θ at the output 输出行星实际 The difference:

[0055] ε 行星 =θ 输出行星理论 -θ 输出行星实际 =θ 输入行星 / i 行星 -θ 输出行星 (2)

[0056] Among them, i 行星 is the transmission ratio of the planetary reducer assembly.

[0057] The fourth step is to perform the transmission accuracy test of the harmonic reducer assembly. Compared with the transmission accuracy test method of the planetary reducer assembly, the input end of the harmonic reducer assembly is connected in series with a circular grating and a servo motor in sequence, and the output angle measurement module uses a prism and a collimator. First, the servo motor of the precision test bench drives the input end of the joint under test to rotate, in order to eliminate the idle clearance of the reducer; secondly, the input angle is reset to zero, and continues to rotate in the same direction until the prism normal at the output end is perpendicular to the collimator plane (that is, the prism cross cursor coincides with the collimator cross cursor), and the servo motor at the input end is fed back to stop rotating, and the actual angle θ of the input end is obtained through the circular grating at the input end. 输入1 ; Again, repeat the above steps to obtain the actual rotation angle θ of the input end when the output end rotates to each face of the prism 输入谐波 =[θ 输入1 θ 输入2 … θ 输入n ] T Finally, the transmission accuracy of the harmonic reducer assembly is calculated as the theoretical rotation angle θ at the output end. 输出谐波理论 The actual rotation angle θ at the output 输出谐波实际 The difference:

[0058] ε 谐波 =θ 输出谐波理论 -θ 输出谐波实际 =θ 输入谐波 / i 谐波 -θ 输出谐波 (3)

[0059] Among them, i 谐波 is the transmission ratio of the harmonic reducer assembly.

[0060] The fifth step is to calculate the transmission accuracy of the drive joint. According to the drive joint transmission accuracy calculation model for space manipulators, the transmission accuracy of the first-stage planetary reducer assembly is converted to the input end of the second-stage harmonic reducer assembly, ε 关节 =ε 行星 / i 谐波 +ε 谐波 , calculate and obtain the transmission accuracy of the driving joints used in the space robot arm.

[0061] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

[0062] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A driving joint transmission accuracy test system for a space manipulator, characterized in that: include: The planetary reducer test module comprises a first-stage driving joint mechanism precision test bench, a planetary reducer assembly of the driving joint, and an output angle measurement module of the planetary reducer assembly; a guide rail is fixedly installed on the first-stage driving joint mechanism precision test bench, and a servo motor, a coupling, a circular grating, and a product bracket are sequentially installed on the guide rail; the planetary reducer assembly is connected to the product bracket through its own mounting stop; the circular grating is used to measure the input end angle of the planetary reducer assembly, the servo motor is used to drive the planetary reducer assembly of the driving joint to rotate to each transmission precision measurement point, and the coupling is used to connect the servo motor and the circular grating; the planetary reducer output angle measurement module is a laser tracker angle measurement system, which is placed on the side of the first-stage driving joint mechanism precision test bench, and is used to convert the point position information of the laser target ball at different measuring points into the actual output angle of each measuring point of the planetary reducer assembly through homogeneous transformation; A harmonic reducer test module comprises a second-stage driving joint mechanism precision test bench, a harmonic reducer assembly of a driving joint, and an output angle measurement module of the harmonic reducer assembly; a guide rail is fixedly installed on the second-stage driving joint mechanism precision test bench, and a servo motor, a coupling, a circular grating, and a product bracket are sequentially installed on the guide rail; the harmonic reducer assembly is connected to the product bracket through its own mounting stop; the circular grating is used to measure the input end angle of the harmonic reducer assembly, the servo motor is used to drive the measured joint to rotate to each transmission precision measurement point, and the coupling is used to connect the servo motor and the circular grating; the harmonic reducer output angle measurement module comprises a prism and a collimator, the prism is installed on the output end test adapter shaft of the harmonic reducer assembly, the collimator is installed at the output end angle test bracket, the output end angle is a fixed value, the collimator captures the prism normal feedback signal until the servo motor stops rotating, and obtains the actual input end angle of the harmonic reducer assembly through the circular grating.

2. A method for testing the transmission accuracy of a driving joint of a space manipulator implemented by a system for testing the transmission accuracy of a driving joint of a space manipulator according to claim 1, characterized in that: Including transmission accuracy test of planetary reducer assembly, transmission accuracy test of harmonic reducer assembly and calculation of transmission accuracy of drive joint; The transmission accuracy test of the planetary reducer assembly includes: S11, perform kinematic calibration of the coordinate system of the output shaft of the planetary reducer joint, and obtain the world coordinate system {i 世界 } and the output coordinate system {i 输出端 }'s pose relationship matrix T 输出端-世界 ; S12, driving the input end of the planetary reducer assembly to rotate to each measuring point through the servo motor of the first-stage driving joint mechanism precision test bench; S13, according to the posture relationship matrix T 输出端-世界 Calculate the difference between the theoretical rotation angle and the actual rotation angle of the output end of the planetary reducer at each measuring point as the transmission accuracy of the planetary reducer assembly; The transmission accuracy test of the harmonic reducer assembly includes: S21, driving the input end of the harmonic reducer assembly to rotate through the servo motor of the second-stage driving joint mechanism precision test bench; S22, the input end rotation angle of the harmonic reducer assembly is reset to zero, and the prism normal of the output end of the harmonic reducer assembly is continued to rotate in the same direction until the prism normal of the output end of the harmonic reducer assembly is perpendicular to the collimator plane, and the servo motor of the second-stage driving joint mechanism precision test bench is fed back to stop rotating, and the actual input end rotation angle is obtained through the circular grating of the second-stage driving joint mechanism precision test bench; S23, repeating S21 and S22, obtaining the actual rotation angle of the input end when the output end of the harmonic reducer assembly rotates until each surface of the prism is perpendicular to the collimator plane; S24, calculating the difference between the theoretical rotation angle of the output end of each measuring point of the harmonic reducer assembly and the actual rotation angle of the output end as the transmission accuracy of the harmonic reducer assembly; The calculation of the transmission accuracy of the driving joint includes: The transmission accuracy of the driving joint for the space robot arm is calculated based on the transmission accuracy of the planetary reducer assembly and the transmission accuracy of the harmonic reducer assembly.

3. The method for testing transmission accuracy of driving joints for a space manipulator according to claim 2, characterized in that: The transmission accuracy of the planetary reducer assembly is ε 行星 =θ 输入行星 / i 行星 -θ 输出行星 ; where θ 输入行星 The servo motor of the first-level driving joint mechanism precision test bench drives the input end of the planetary reducer assembly to rotate between adjacent measuring points, i 行星 is the transmission ratio of the planetary reducer assembly to be tested, θ 输出行星 It is the angle between the lines connecting adjacent points and the coordinate origin.

4. The method for testing transmission accuracy of driving joints for a space manipulator according to claim 3, characterized in that: The input end of the planetary reducer assembly rotates θ in sequence 输入行星 After the angle is measured, the laser tracker angle measurement system is used to measure the output end laser target ball in the world coordinate system {i 世界 Spatial position P 世界 =[P 1世界 P 2世界 … P n世界 ] T ; Through the pose transformation matrix T 输出端-世界 Get the laser target ball in the coordinate system {i 输出端 The spatial position P of 输出端 =[P 1输出端 P 2输出端 … P n输出端 ] T ; The coordinate system of the output end of the planetary reducer assembly {i 输出端 } is used as a reference, and the angle between the adjacent points and the coordinate origin is the actual rotation angle θ at the output end of the planetary reducer assembly. 输出行星 =[θ 1输出 θ 2输出 … θ n输出 ] T ; Calculate the transmission accuracy of the planetary reducer assembly, which is the difference between the theoretical rotation angle and the actual rotation angle at the output end of the planetary reducer assembly.

5. The method for testing transmission accuracy of driving joints for a space manipulator according to claim 2, characterized in that: The transmission accuracy of the harmonic reducer assembly is ε 谐波 =θ 输入谐波 / i 谐波 -θ 输出谐波 ; where θ 输入谐波 is the actual rotation angle of the input end when the output end of the harmonic reducer assembly is rotated to the point where the prism faces are perpendicular to the collimator plane, i 谐波 is the transmission ratio of the harmonic reducer, θ 输出谐波 It is the actual rotation angle of the input end when the output end of the harmonic reducer assembly rotates to each face of the prism.

6. The method for testing transmission accuracy of driving joints for a space manipulator according to claim 2, characterized in that: The transmission accuracy of the driving joint of the space manipulator is ε 关节 =ε 行星 / i 谐波 +ε 谐波 ; where ε 行星 is the transmission accuracy of the planetary reducer assembly, i 谐波 is the transmission ratio of the harmonic reducer assembly, ε 谐波 Transmission accuracy of harmonic reducer assembly.

7. The method for testing transmission accuracy of driving joints for a space manipulator according to claim 2, characterized in that: The driving joint is a multi-stage reducer series structure.

8. The method for testing transmission accuracy of driving joints for a space manipulator according to claim 2, characterized in that: The planetary reducer assembly and the harmonic reducer assembly are measured respectively by using a laser tracker, a collimator and a prism.

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