一种电磁耦合集成角度传感器的关键模块设计
Design of Key Modules in An Electromagnetic Coupling Integrated Angle Sensor
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摘要: 设计了一种基于电磁耦合原理的集成角度传感器. 该传感器由两块电路板与一片专用信号处理芯片组成,在电路板上实现了激励线圈、接收线圈和反馈线圈的设计,通过交变电磁场之间的电磁耦合完成角度信息的转换. 传感器芯片设有增益编程模式、零度标定模式,可消除制作工艺与装配过程带来的误差,并实现零度标定;以CORDIC算法为核心设计了角度解码电路,经过误差补偿,大大减小了CORDIC算法在反正弦运算中的误差. 经实验测试,数字电路组成的关键模块工作正确,其角度解码范围为0°~120°,误差小于0.05°,满足传感器0.5°的整体设计要求.Abstract: 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 function 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.
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