Research on magnetic encoder based on temperature compensation

Abstract

As a type of sensor intended for the real-time feedback and dynamic monitoring of angular velocity and angular displacement, encoder is widely used in electric vehicles, servo closed-loop control systems, household appliances, cameras and many other fields. In order to reduce the temperature drift caused by ambient temperature to the magnetic encoder, a self-tuning temperature compensation algorithm is proposed in this paper based on the calibration principle. The rationale of this algorithm is that error function is designed to calculate the error at different temperature and room temperature, and the partial derivative is calculated to update the weight coefficient. Finally, the least square model is applied to establish the relationship between Hall output amplitude and temperature coefficient, thus correcting the temperature drift of the encoder. According to the experimental results, the self-tuning temperature compensation algorithm is applicable to compensate for and correct the temperature drift caused by the amplitude of Hall signal at different ambient temperatures. The ultimate accuracy of temperature drift is improved by 0.2° for the encoder.