Design and Development of High Precision Magnetic Encoder Based on TMR MEMS Device

The MEMS magneto-sensitive chip based on the TMR principle is used as the sensitive element of the magnetic encoder. In terms of hardware development, after optimizing the design of the magnetic circuit, developing a precise rotating structure, designing a stabilized power supply circuit and a low-noise signal conditioning circuit, and digitally converting the analog voltage signal with high signal-to-noise ratio through analog-to-digital conversion and then entering the microprocessor. A high-precision magnetoelectric rotary encoder was designed and developed, and an automatic acquisition system was used to collect and store the encoder data. In terms of program design, a data processing, correction, and calibration algorithm was designed and written for the original output data of sensitive components, and MATLAB software was used to simulate, calculate and verify the angle data calculated by the encoder for further verification. The developed encoder has an angle measurement accuracy under actual working conditions. The encoder is installed on a high-precision time grid turntable system for testing, and the encoder's testing accuracy has reached a good level of 0.0469°.