Error Analysis And Compensation System Of The Absolute Encoder

Optical encoder is a position measuring instruments, which is widely used in control technology. In order to monitor the position of the target more quickly and accurately, we need to propose the resolutions about precision measurement and compensation of the encoder. Optical encoder error mainly includes manufacturing error code disc, shaft shaking, code disk eccentricity, interpolation error, quantization error and detection errors. These errors come from the encoder disk characterization, mechanical alignment, electronics processing process, and these factors will affect measurement accuracy. Therefore, analysising the accuracy of the encoder error compensation is the key to the encoder manufacturing problem.Nowadays, detecting the precision of optical encoder mainly uses static detection. But it does not reflect the actual working conditions in the precision, which can not compensate error comprehensively. Some devices reference dynamic measurement but they just arm at subdivision error. In this paper, due to practical applications for requirements of the absolute encoder dynamic accuracy system, error detection and compensation system should contain measurement of the accuracy and fault information about the encoder. The driver of the precision detection device is a motor and it regards high resolution encoder as the measurement reference value. when the motor is driving the device precision, measurements are executed in real time angle measurements between the two encoders at different locations. At the same time, the system calculates subdivision error and fault analysis of raster signal. Combining the results of precision detection and error analysis, I propose error compensation measurements.The issue of this paper is about resolution method for detection and error compensation issues about the encoder. Analysised causes of the encoder error and impact of various factors on the accuracy; proposed method to calculate parametric and subdivision phase error signal by the harmonic spectrum analysis; designed interpolation error compensation system, which is made up of a DSP chip as the core of data acquisition systems and PC as the core of the optical encoder software; proposed error correction solution to improve the accuracy; simulated subdivision precision detection and compensation scheme for tangent subdivision method and verificated that the compensation algorithm is effective.