摘  要：高分辨率磁编码器设计方案采用霍尔器件感应随转子旋转的两极磁环产生的磁场得到一对正交的电压信号，经A/D变换后通过CORDIC算法对该信号进行解码，从而获得转子的位置信息。磁编码器的分辨率及测速范围可根据要求自行定制，能够提供增量式输出（正交A/B、z信号；最小有效位信号、无刷直流电机换向所需的U、V、W信号）和绝对式输出（脉宽调制信号、模拟信号）等多种模式的转角位置信号。实验结果证明磁编码器可以提供精确的绝对角度位置信息，在一定转速下每旋转一周可以输出1024个位置信息，即分辨率达到0.35°。磁编码器提供的多种增量式输出信号能够在一定的精度范围内代替多种光电编码器，从而降低了系统成本，有实际应用价值。
关键词：磁编码器;CORDIC;单片机；无刷直流电机；实验

Abstract: This paper presented a new high resolution magnetic encoder based on an 8 bits microprocessor.The Hall devices deteced the magnetic field which had generated by a two poles magnetic ring rotating with the rotor,and then output a pair of quadrature voltages.After analog to digital converter，the position of the rotor can be obtained by decoding the quadrature voltages with the CORDIC algorithm.The resolution and rotational speed measurement range of the magnetic encoder can be customized according to the demands.The signals of velocity and position are provided with incremental modes(quadrature A/B signal;least significant bit signal;3-phase commutation signals for brushless DC motor)and absolute modes(pulse width modulated signal;analog signal)at the same time.The experiment results showed that the magnetic encoder can provide accurate absolute angular position information,and the absolute angle measurement provided instant indication of the angular position with 1024 positions per revolution,namely a resolution of 0.35°. The incremental output makes the encoder suitable for replacement of various optical encoder in some resolution range with a low cost.
Key Words: Magnetic encoder;CORDIC;Microprocessor;Brushless DC motor;Experiment