Design Of Angle-measuring System For High-precision And Comprehensive Performance Test Bench For Precision Reducer

Precision reducer is the key component of industrial robot,the performance and quality of reducer are restricted by measuring instruments.This paper designs a measurement system in the high precision comprehensive performance tester of precision reducer,which can realize the accurate measurement of angle,angular velocity and angular position.The angle measurement system uses high precision absolute circular grating and two diametrically mounted reading heads as the basic components.Based on the principle of sensor pre-position and rigid connection mode,the measuring point is set near the measured angular displacement to approximate the true rotation of the reducer.The mechanical structure of the angle measurement system is designed to reduce the influence of eccentricity and inclination on the measurement of circular grating.The software is designed to collect the measurement data of the reading head and convert the angular position into angular displacement and angular velocity.The multi-faceted prism combined with the photoelectric autocollimator is used to discretely calibrate the angle measuring system of the high and low speed ends,and the multi-faceted prism mounting device is designed.The multi-faceted prism is connected with the high-speed measuring shaft system by means of the expansion structure.The multi-faceted prism and the circular grating in the detector can be rotated coaxially and synchronously.The upper computer program controls the motor in the instrument to drive the measurement shaft rotation,realizes the calibration data collection,and obtains the angle error by using the data processing program.The error compensation model is established by cubic spline fitting and harmonic analysis.The method of using the model is studied to realize the compensation of the diagonal position.The angle measurement accuracy of the whole instrument after compensation is verified by experiment,and the error compensation effect of the model is analyzed.The experimental results show that the final measurement accuracy of the angle measurement system is 2 seconds,which meets the accuracy requirements of the high-precision comprehensive performance detector for the angle measurement system.