应用于压电快反镜的高性能角度传感器设计

High-performance angle sensor design for piezoelectric fast steering mirror

压电快反镜系统中,反射镜的偏角测量精度是影响系统执行精度的关键。设计了一种基于直流电桥的电阻式角度传感器,采用低通滤波器和高精密仪表放大电路对微弱的电信号进行精准放大;采用单端—差分放大器构成AD驱动电路,将单端信号做进一步差分放大处理,从而为A/D转换提供低噪声精准模拟输入,最后搭建电路系统进行性能测试。实验结果表明,角度传感器能实现1.59μrad的角度分辨率,非线性误差小于0.06%,且波动小,满足压电快反镜系统对角度传感器的性能指标要求。

In the piezoelectric fast steering mirror system,the declination measurement accuracy of the mirror is the key to the execution accuracy of the system.A resistive angle sensor based on a DC bridge was designed.A low-pass filter and a high-precision instrumentation amplifier circuit were used to precisely amplify the weak electrical signal;a single-ended-differential amplifier was used as the AD driver circuit which can further differentially amplify the single-ended signal,so as to provide a low-noise and accurate analog input for A/D conversion.Finally,a circuit system was built for performance test.The experimental results show that the angle sensor can achieve an angle resolution of 1.59μrad,the stability is as high as 1/7827,and the nonlinear error is less than 0.06%,which meets the performance index requirements of the angle sensor for the piezoelectric fast steering mirror system.