仿真转台伺服系统动态模型辨识与计算

Dynamic model identification and computation of servo system for simulation turntable

仿真转台广泛应用于光电制导导引头及其对抗的仿真,对某型仿真转台进行高精度模型辨识可以有效提高系统的动态控制精度和设计效率。基于此,提出了一种转台伺服系统频率特性自动测试方法,根据测试数据采用参数递阶辨识方法分段拟合得到了被控对象的高精度传递函数模型。辨识结果与实测数据相比:在体现伺服系统重要特征的中低频段,幅度绝对误差<1 d B,相位绝对误差<2°;在高频段,得到了复杂的机械谐振环节特性,验证了被控对象传递函数模型的准确性。对于转台的动态精度计算,采用频率设计分析建模方法,结合被控对象高精度传递函数和实际校正环节模型得到了转台的动态精度计算模型,通过比较同一输入情况下实测动态误差与模型输出误差数据验证了模型准确性,结果表明了该方法的有效性。建立的动态精度计算模型能够反映实际系统的动态过程和动态误差变化规律,也为同类设备伺服系统的模型辨识和动态精度分析计算提供了方法。

Simulation turntable is widely used in the simulation on electro-optical guided seeker and its countermeasure. Dynamic control precision and design efficiency of the servo system could be effectively improved by means of using parameter identification to obtain the high precision transfer function model of the simulation turntable for laser guided seeker. Based on this, a frequency response auto-testing method was proposed according to the servo system configuration of the simulation turntable, and the high precision transfer function model of the controlled object was obtained by adopting the parameter hierarchical identification. The comparison with actual data shows that the absolute magnitude error of the identification result was less than 1 d B, the absolute phase error was less than 2° in low frequency, and the mechanical syntony characteristic was also gained in high frequency of the servo system. Then the computation method on dynamic control precision for tracking servo system was analyzed, the closed-loop dynamic precision model was set up by frequency design modeling method combined with the adjustable control model and the high precision transfer function model of the controlled object. The simulation analysis, by contrasting actual tested dynamic control error data with simulation error data, shows that the dynamic control precision computation model can accurately show the variety rule of the dynamic error and dynamic process of the servo control system. The research results provide a model identification method to support and analyze the dynamic control precision modeling of the servo control system for the same type of devices.