Design of Key Modules in An Electromagnetic Coupling Integrated Angle Sensor.

An integrated angle sensor based on electromagnetic induction is proposed. The sensor consists of a specific signal processing chip and two external printed circuit boards. The design of on-board excitation coil, receiver coil and feedback coil were realized and the conversion of angles was completed through electromagnetic coupling between alternating electromagnetic fields. Gain-programming mode was set up in the sensor chip to eliminate errors caused by producing and assembling process, while zero-calibration program was executed to implement zero calibration. Angle decoding circuit was designed using CORDIC algorithm, including the {unction of error compensation to increase the precision in computing arcsine. Experimental results indicate that the critical digital circuit block could work correctly. The decoding scope of the block ranges from 0° to 120° with the error less than 0.05°, which can meet the 0.5° precision demand of the sensor. [ABSTRACT FROM AUTHOR]