连续回转马达电液伺服系统辨识及控制

System identification and control of the electro-hydraulic servo system of a continuous rotary motor

针对连续回转电液伺服马达摩擦力矩和泄漏量的周期性变化对整个系统产生周期性干扰的问题,建立了连续回转马达电液位置伺服系统的数学模型,采用正弦扫频信号作为激励信号,根据连续回转马达自身结构特点,每间隔10°对连续回转马达进行整周的闭环参数辨识.对采集的每组输入、输出数据对序列,采用基于高斯-牛顿优化算法的预报误差法进行系统模型参数辨识,得到了在整周内系统模型参数的变化范围.针对马达系统参数时变及非线性不确定性因素,依据连续回转电液伺服马达设计指标要求,结合系统模型参数辨识结果,利用定量反馈理论设计了一种基于输入信号微分前馈的二自由度QFT(quantitative feedback theory)鲁棒控制器,实验证明连续回转马达符合性能指标要求,证明了该辨识及控制方法的可行性.

Due to the periodic interference problems caused by periodic changes of the friction torque as well as by leakage in the entire system of a continuous rotary electro-hydraulic servo motor,the mathematical model of a continuous rotary motor electro-hydraulic position servo system was established.The model was constructed using sine sweep signals as excitation signals.A closed-loop parameter identification experiment of the entire cycle of the continuous rotary motor was carried out by each interval of 10° according to its own structural characteristics.Each of the collected input and output data series and prediction error methods based on a Gauss-Newton optimization algorithm were adopted to identify the parameters of the system model.The changing range of the system model parameters in the whole cycle was also obtained.According to the time-varying of motor system parameters and nonlinear uncertainties,and based on design requirements of a continuous rotary electro-hydraulic servo motor,a QFT（quantitative feedback theory）robust controller with two degrees of freedom was designed.The controller was also based on the differential feed-forward of the input signal,and it adopted the quantitative feedback theory,combining the system model parameter identification results.The controller＇s value was proven through an experiment which showed that the motor meets the performance demand,indicating that this identification and control method is feasible.