Research on Fast Calibration of Rotary Encoder Based on Particle Swarm Optimization

In order to solve the problem that rotary encoder has high installation technology requirement in the use of large aperture and high precision radio telescope, professional calibration equipment is required, and the encoder accuracy needs to be further improved by establishing error correction model after a period of work. The fast calibration method of encoder is studied in this paper. A fast calibration method of rotary encoder based on Particle Swarm Optimization (PSO) is proposed. According to the principle that the angular displacement change rate is constant when the servo motor is running at a constant speed, the encoder installation error is obtained after the encoder sampling data is compared with the servo motor's constant speed reference value. Use the PSO algorithm to quickly fit the error and calibrate the encoder. A test platform is established, which is used to verify the encoder calibration method. According to the test results it is found that the encoder calibration method could restore the actual measurement accuracy of a high-resolution encoder with a high installation error to 3 to 4 digits. It provides a simple method to monitor and correct the encoder of large aperture radio telescope periodically.