舰载光电伺服设备的系统辨识研究

Shipboard photoelectric equipment servo system identification

系统辩识即获取电机机械时间常数Tm和对应的固有放大倍数K。舰载光电系统由于受到横摇、纵摇、艏摇的扰动,其系统辩识的可信度及精度直接影响到调节器参数的设定,从而对稳态和动态精度会有很大的影响。常规公式法求电机机械时间常数在实际应用中非常不便,并且大多数场合不能求得Tm。本文以PC104硬件平台为依托,推导出的近似逼近e指数函数作为阶跃法获取系统辨识的理论依据,并设计了友好的人机交互界面可以方便的显示、修改系统辩识的结果。试验分析表明,应用Origin拟合e指数函数使阶跃法得到的Tm和K拟合可信度达到96%以上,其拟合误差小于0.1,精度完全满足使用要求。解决了实际工程中获取Tm和K精度低、可信度不高的难题。此方法成功地应用在项目中,并对求得电机机械时间常数有很好的通用性和借鉴性。

Obtaining the motor mechanical time constant Tm and inherent magnification K is knowed as system identify. Ship-borne photoelectric system was disturbed due to the roll, pitch, bow wave disturbance,and the reliability and accuracy of the system discerniblile directly affect the regulator parameter setting. Thereby, the steady state and dynamic accuracy will confront serious influence. Conventional formula method for motor mechanical time constant in the practical application is very incon- venient, and most of the occasions for Tm can＇t be gotten. Based on PC104 hardware platform, this paper deduced the approximate approach e exponential function as step method for system identification that is the theoretical basis, designed a friendly human-computer interaction interface to display and modify the result of the system on discerniblile easily. By test ana exponential function can make the step method of Tm and K fitting cred ysis. applying Origin fitting e bility more than 96%, the fitting error is less than 0.1, accuracy can meet the needs completely. The problem of low accuracy and credibility has been solved for getting Tm and K in the practical engineering. This method is successfully used in some projects, and the results show that the method is feasible and practical.