小角度摆动扫描控制系统的分析与实现

激光测距仪对摆动扫描控制系统提出了特殊的要求(摆动幅度为±0.125°，摆动频率为2～8 Hz)。在对系统进行建模与仿真分析的基础上，针对其中存在光栅码盘位置检测精度低、电机驱动电流小、易受外界干扰等问题，提出了一种新的工程实现方法。首先采用有限转角无刷直流力矩电机作为执行元件和挠性枢轴连接，可以减小力矩波动和机械摩擦；然后通过电学细分的方法提高光栅的分辨率；最后采用电流反馈和速度反馈相结合的PID控制策略提高系统的性能。试验结果表明：此方法可以满足摆动扫描控制系统对低转速、小角度、高精度控制的要求。

Analysis and implementation of limited angle swing scanning control system

The laser rangefinder brings forward special requirement (swing amplitude ±0.125°,swing frequency 2-8 Hz) to the swing scanning control system. Through modeling and simulating, the limited angle swing scanning control system has some problems, such as low precision of optical grating, small drive current of motor, easily interfered by the environment. In order to solve these problems in laser rangefinder, a kind of new project realization method is proposed. First, the limited angle brushless DC torque motor and flexibility pivot are adopted. So the torque ripple and mechanical friction are decreased. Then, the electron-subdivision is adopted to improve the resolution of optical grating. At last, the system uses current feedback and velocity feedback control, so that the whole performance is improved a lot. The experimental result indicates that the method can resolve the difficult problem of low speed, small angle and high precision control.