CN-122015737-A - Automatic positioning accuracy testing system for servo motor and servo joint

CN122015737ACN 122015737 ACN122015737 ACN 122015737ACN-122015737-A

Abstract

The invention belongs to the technical field of servo system performance testing methods, in particular to an automatic positioning accuracy testing system for a servo motor and a servo joint, wherein a whole set of system hardware main body is mounted on a high-rigidity opposite-support testing bench and comprises a reference positioning module, a time grating signal acquisition module, a servo driving control module, a load simulation module, a multi-dimensional sensing module, a main control and data processing module and a man-machine interaction module; according to the invention, the high-precision time grating encoder is used as a position measurement reference, the time grating encoder based on the principle of 'using time to measure space' is used as a measurement reference, the ultra-high measurement precision, the strong anti-interference capability and the high cost performance are achieved, the stable measurement performance can be maintained under the low-speed heavy-load working condition, the equipment cost and the environment use requirement are greatly reduced, the scene limit of high-precision test equipment is broken, and the full-scene application requirements of laboratory precision test and production line batch test can be simultaneously met.

Inventors

SUN ZEJU
LI ZHANMENG
ZHU WANG
LI YALONG
XIONG XIAOMING

Assignees

江苏意优机器人科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260330

Claims (10)

1. The automatic test system for the positioning accuracy of the servo motor and the servo joint is characterized in that a whole set of system hardware main body is mounted on a high-rigidity opposite-support test bench and comprises a reference positioning module, a time grating signal acquisition module, a servo driving control module, a load simulation module, a multi-dimensional sensing module, a main control and data processing module and a man-machine interaction module; The reference positioning module takes a high-precision time grating encoder as a core and is used for providing an absolute position reference for a servo motor to be measured, a servo joint or a frameless moment servo system, a measuring shaft of the time grating encoder is coaxially and rigidly connected with an output shaft of a measured piece, the time grating encoder adopts an absolute time grating displacement sensor, and displacement measurement is realized in a 'time' measuring 'space' based on a space-time coordinate conversion principle; The time grating signal acquisition module is connected with the reference positioning module and is used for acquiring the position signal output by the time grating encoder in real time and finishing signal decoding, filtering and preprocessing; the servo drive control module is connected with the servo motor/servo joint to be tested and is used for transmitting a motion control instruction to the tested piece and synchronously collecting real-time feedback data of the encoder of the tested piece; the load simulation module is connected with an output shaft of the tested piece and is used for providing an adjustable simulation load for the tested piece and reproducing different working conditions such as no-load, rated load, variable load and the like; the multi-dimensional sensing module is used for collecting torque, vibration, temperature and noise data in the test process of the tested piece and providing multi-dimensional data support for positioning accuracy error analysis; The main control and data processing module is respectively in bidirectional communication with the time grating signal acquisition module, the servo drive control module, the load simulation module and the multi-dimensional sensing module, is provided with an upper computer management and control system based on LABVIEW development, and is used for realizing full-automatic control of a test flow, synchronous acquisition and fusion analysis of multi-source data and simultaneously completing calculation of related indexes of positioning accuracy and error tracing; the man-machine interaction module is connected with the main control and data processing module and is used for testing parameter configuration, starting and stopping of a testing process, real-time display of testing data and automatic generation of a testing report.
2. The automatic test system for the positioning accuracy of the servo motor and the servo joint according to claim 1 is characterized in that the reference positioning module comprises a high-accuracy time grating encoder, a coaxial switching assembly and a fixed rack, wherein the time grating encoder adopts an absolute time grating displacement sensor, the resolution ratio of the time grating encoder is better than +/-0.5 angular seconds, the measurement accuracy of the time grating encoder is better than +/-1 angular second, the coaxial switching assembly comprises a corresponding shape switching disc, a corresponding shape switching shaft and a high-rigidity diaphragm coupler, the coaxial switching assembly is used for eliminating coaxiality errors between an output shaft of a tested piece and a measuring shaft of the time grating encoder, the fixed rack is arranged on a butt test rack, and a positioning reference surface and an adjustable mounting position are arranged on the fixed rack, so that the servo motor, the servo joint and a frameless moment servo system with different flange sizes are adapted.
3. The automatic test system of positioning accuracy of a servo motor and a servo joint as set forth in claim 1, wherein said time grating signal acquisition module and said servo drive control module are of a dual-core coordinated architecture of FPGA+STM32, wherein said FPGA chip is used for realizing synchronous parallel acquisition of time grating encoder signals and encoder signals of a tested piece, and sampling synchronization error of the two signals is less than 1 And the STM32 chip is used as a main control core for realizing interaction of motion control logic, load regulation logic and data.
4. The automatic test system for positioning accuracy of a servo motor and a servo joint according to claim 3, wherein the servo drive control module comprises a sine wave servo driver, a high-speed communication unit and an encoder signal branching unit, wherein the encoder signal branching unit divides an output signal of a tested piece with an encoder into two paths, one path is connected with the servo driver for servo closed-loop control, the other path is connected with an FPGA chip for synchronous acquisition of position data, and sampling delay and data distortion caused by communication speed limitation of a traditional driver are avoided.
5. The automatic positioning accuracy testing system for the servo motor and the servo joint according to claim 1, wherein the load simulation module comprises a hysteresis dynamometer, a servo electric cylinder, a torque rotation speed sensor and a loading controller, wherein the hysteresis dynamometer is used for providing continuously adjustable resistance torque for the servo motor/the servo joint to be tested and simulating a load under a rotating working condition, the servo electric cylinder is matched with the force sensor to provide an axial load for the linear motion type servo joint and simulate an actual working condition, and the loading controller receives an instruction of a main control and data processing module and automatically adjusts the load and keeps the load stable.
6. The automatic test system for the positioning accuracy of the servo motor and the servo joint according to claim 1, wherein the multi-dimensional sensing module comprises a torque rotating speed sensor, a three-axis vibration sensor, an infrared temperature array sensor and a noise sensor, wherein the torque rotating speed sensor is coaxially arranged between an output shaft of a tested piece and a load simulation module and is used for collecting real-time output torque and rotating speed, the three-axis vibration sensor is fixed at a shell and an output end of the tested piece and is used for collecting vibration data, the infrared temperature array sensor is used for monitoring real-time temperature distribution of a stator, a bearing and a transmission part of the tested piece, and the noise sensor is used for collecting noise data in the test process.
7. The automatic test system for positioning accuracy of a servo motor and a servo joint according to claim 1, wherein a standardized test program library is built in the main control and data processing module, positioning accuracy test, repeated positioning accuracy test, reverse difference test and track tracking accuracy test processes can be automatically executed, standardized test programs of single-circle 36 point position uniform distribution and forward and reverse reciprocating circulation can be built in, full-process automatic operation of single-circle 36 stepping rotation and multi-cycle forward and reverse reciprocating test can be executed, a built-in accuracy index calculation unit can complete test data processing and accuracy index calculation through a preset statistical method, meanwhile, a built-in error tracing analysis unit can disassemble a test process into a motion planning link, a servo driving link, a motor body link and a mechanical transmission link, and the influence degree of each link on positioning accuracy is quantified by comparing position instruction data of each link, encoder feedback data and time grating encoder reference position data.
8. The automatic test system for positioning accuracy of a servo motor and a servo joint according to claim 1, wherein the main control and data processing module is further provided with a data preprocessing unit, the data preprocessing unit adopts an S-G filtering algorithm to conduct noise reduction processing on collected position signals and torque signals, interference of random errors and encoder line errors on test results is eliminated, and meanwhile time stamps of collected data of all channels are synchronously corrected through self-delay of a pre-calculated system, and time consistency of multi-source data is guaranteed.
9. The automatic test system for positioning accuracy of a servo motor and a servo joint according to claim 1, wherein the man-machine interaction module is internally provided with a parameter configuration template, and the parameter configuration template comprises a servo motor test template, a SCARA robot servo joint test template and a six-axis robot joint test template, wherein a standard test parameter, a test point position and a qualification threshold corresponding to a tested piece are preset in the template, and a self-defined test flow is supported, so that a multi-section test stroke, a multi-point position cycle test and a variable speed/variable load continuous test can be set, and a standardized test report can be automatically generated, wherein the report comprises test data, an accuracy index, an error analysis result and qualification judgment.
10. The automatic test method for the positioning accuracy of the servo motor and the servo joint based on the time grating encoder is characterized by adopting the test system as claimed in any one of claims 1-9, and comprising the following steps: The method comprises the following steps that 1, according to the type of a tested piece, the installation of a tested servo motor, a servo joint or a frameless moment servo system on a fixed rack of a butt-test rack is completed, an output shaft of the tested piece is coaxially connected with a time grating encoder and a load simulation module through a coaxial switching assembly, and the hardware wiring and communication connection of each module are completed; Step 2, selecting a corresponding test template or configuring test parameters in a self-defined mode through a LABVIEW upper computer interface of the man-machine interaction module, wherein the test parameters comprise test points, movement speed, cycle test times, load size and sampling frequency, and the main control and data processing module automatically generates a test flow according to the configuration parameters; Step 3, the system executes initialization self-checking, zero calibration of the grid encoder and the tested piece self-carried encoder, zero calibration of each sensing module, no-load debugging of the load simulation module, and enters a to-be-tested state after the self-checking is passed; Step 4, the main control and data processing module transmits a motion instruction to the tested piece through the servo drive control module, controls the tested piece to move to a target test point according to a preset flow, synchronously collects reference position data of a time grating encoder through the time grating signal collection module, collects feedback position data of the self encoder of the tested piece through the servo drive control module, and synchronously collects torque, vibration and temperature data through the multi-dimensional sensing module; Step 5, finishing the reciprocating cycle test of the appointed times at each test point, recording the actual position data, the motion response data and the multidimensional sensing data of each arrival point, controlling the measured piece to return to zero when the single-circle 36-point standardized test is executed, sequentially rotating with 1/36 circle as step distance, executing the reverse 36 cycle test after finishing 36 forward cycles when the grid reference position and the measured piece feedback position are synchronously read when the target point is rotated, accumulating the whole set of forward and reverse reciprocating flow to execute 5 full cycles, and automatically calculating the positioning precision, the repeated positioning precision and the reverse difference core index of the measured piece by a main control and data processing module after finishing all point tests; step6, the system executes error tracing analysis, and the influence of each link of motion planning, servo driving, a motor body and mechanical transmission on the positioning precision is separated by comparing the reference position data, the encoder feedback data, the motion planning instruction data and the multidimensional sensing data, so as to position the main error source; And 7, after all the test flows are completed, the system automatically stores the original test data, generates a standardized test report according to the test result, and displays and outputs the standardized test report in a man-machine interaction module.

Description

Automatic positioning accuracy testing system for servo motor and servo joint Technical Field The invention belongs to the technical field of servo system performance testing methods, and particularly relates to an automatic positioning accuracy testing system for a servo motor and a servo joint. Background The servo motor and the servo joint are used as core execution components of industrial robots, precision machining equipment and automatic production lines, and the positioning accuracy directly determines the operation accuracy and the operation stability of the terminal equipment. Along with the rapid development of the precision manufacturing industry, higher requirements are put forward on the positioning precision and repeated positioning precision of the servo system, and correspondingly, a high-precision and high-automation test system is required to comprehensively detect and evaluate the positioning precision of the servo motor and the servo joint. The existing servo motor and servo joint positioning precision test system still has the difficult-to-solve industrial pain points, the core is represented by two large dimensions, firstly, the measurement standard cannot be considered in terms of measurement precision, use cost and scene suitability, the laser interferometer type high-precision scheme is high in equipment cost, severe in requirements on conditions such as environment temperature and humidity, vibration and air flow, operation and debugging thresholds are high, the conventional photoelectric encoder type scheme is difficult to deploy in batches on a production site, the conventional photoelectric encoder type scheme is limited by a grating dividing process, the problems of insufficient precision and weak anti-interference capability are easily caused under the working condition of low speed and heavy load, two types of main flow schemes cannot be simultaneously matched with the requirements of a laboratory precision test and an industrial site batch test for a plurality of scenes, meanwhile, the conventional test scheme has obvious defects in terms of test performance and functional integrity, the problem that the system errors are easily acquired in synchronization due to the mode of data communication of a driver, the error of a control command, the feedback of a tested piece and the reference position data are not easy to be introduced, the problem that the automatic degree is low, the precision value measurement is only can not be completed, and the final error source is difficult to be realized due to the fact that the error quantization of the test result is severely limited by the conventional scheme and the test result is severely limited in terms. Disclosure of Invention In order to overcome the defects of the prior art, the embodiment of the invention provides an automatic test system for positioning precision of a servo motor and a servo joint, which uses a time grating encoder as a high-precision position reference, builds a full-automatic test platform compatible with multiple types of tested pieces and multiple working conditions for testing, realizes accurate measurement and error tracing analysis of related indexes of positioning precision, and solves the problems of insufficient precision, low degree of automation, poor compatibility and difficult error tracing of the traditional test system. In order to achieve the above purpose, the present invention provides the following technical solutions: a servo motor and servo joint positioning accuracy automatic test system is characterized in that a whole set of system hardware main body is loaded on a high-rigidity opposite support test bench and comprises a reference positioning module, a time grating signal acquisition module, a servo drive control module, a load simulation module, a multi-dimensional sensing module, a main control and data processing module and a man-machine interaction module. The invention further provides a measurement reference core of the system, the reference positioning module is composed of a high-precision time grating encoder serving as a core component, a coaxial switching assembly and a fixed rack, the time grating encoder adopts an absolute time grating displacement sensor, the core realizes displacement measurement by using a space-time coordinate conversion principle and measuring space in time, compared with a traditional photoelectric encoder, the reference positioning module has higher resolution, stronger anti-interference capability and lower low-speed measurement error, the resolution is better than +/-0.5 corner seconds, the measurement precision is better than +/-1 corner seconds, the test reference requirement of an ultrahigh-precision servo system can be met, the coaxial switching assembly comprises a correspondingly-shaped switching disc, a correspondingly-shaped switching shaft and a high-rigidity diaphragm coupler, the coaxiality error between an output shaft of a measured p