针对制导弹药激光目标模拟系统中对光斑尺度控制的需求进行研究。根据系统对光斑张角的变化范围、变化最大速率和控制精度的设计指标要求，对光斑尺度控制系统进行数学建模，给出了力矩电机与平台负载的传递函数，并利用ELMO 驱动控制器、直流力矩电机构成单向有限角位置伺服控制，内部实现电流反馈、速度反馈和位置反馈的闭环控制。系统测试实验结果表明，直流力矩电机闭环伺服带宽82.1 Hz，光斑张角从0.5 mrad 变化到5 mrad 的最大误差为112.1 μrad，小于设计要求的0.15 mrad；光斑张角从5 mrad 变化到90 mrad 的最大误差为326.1μrad，小于设计要求的0.5 mrad。光斑张角变化范围内，其误差均在设计误差范围内，从而验证了控制策略的可行性。

Size of laser facular control unit in laser target simulation system for guided munitions was studied. According to the design index that this system requires for variation range, the maximum rate of changes and control accuracy of the field angle of facular, mathematical model of size of laser facular control unit was established. Then, servo control system with unidirectional limited angular position was composed of an ELMO driver-controller and a DC torque motor，as a result, current feedback, velocity feedback and position feedback made the closed loop control be realized inside the system. Experimental results of the system testing indicate that closed loop servo bandwidth of the DC torque motor is 82.1 Hz，and field angle of facular changed from 0.5 mrad to 5 mrad is 112.1 μrad, which is less than 0.15mrad that the design requires. The maximum error of the field angle of facular changed from 5 mrad to 90 mrad is 326.1 μrad, which is also less than 0.5 mrad that the design requires. Within the variation range of the field angle of facular, its error is in the designed reasonable error range, which can ensure that the control strategy meets the performance requirement of system.