基于动态理论模型的电液伺服加载前馈补偿复合控制系统

Feedforward compensation composite control for electro-hydraulic servo loading based on dynamic theoretical model

针对一般电液伺服系统存在的非预期负载扰动和非线性干扰等问题,为了提高系统的自适应能力和动态响应的品质,减小系统跟踪和输出响应的误差,提出了一种基于动态理论模型的电液伺服加载前馈补偿复合控制方法。首先,阐释了电液伺服试验台的结构组成及其数学模型,分析了系统力矩控制和位置控制的结构关系;然后,论证了自适应前馈补偿复合控制的伺服原理,阐述了以调速理论模型和实际模型的误差函数作为调速依据的前馈补偿和复合控制的原理和方法;最后,进行了系统仿真,同时为了验证基于动态理论模型的自适应前馈补偿复合控制策略的合理性和有效性,对伺服系统进行了加载试验。研究结果表明:采用该复合控制策略可以精确算出对伺服马达进行转速补偿的基准值和调整参数,系统动态响应速度比采用传统闭环控制算法提高了8%以上;系统控制器自适应能力和抗扰动性能也明显优于采用传统PI闭环控制及模糊PI闭环控制算法的系统;通过对比分析0.2 Hz和0.5 Hz的正弦响应曲线可知,该系统的位置跟踪曲线性能最优,控制精度最高,实际输出值的误差也最小。

In response to unexpected load disturbances and nonlinear disturbances in general electro-hydraulic servo systems,in order to improve the adaptive ability and dynamic response quality of the system,and reduce tracking and output response errors,a scheme for feedforward compensation composite control of electro-hydraulic servo loading based on dynamic theoretical model was proposed.Firstly,the composition structure and mathematical model of the electro-hydraulic servo test bench were explained,and the structural relationship between system torque control and position control was analyzed.After that,the servo principle of adaptive feedforward compensation composite control was demonstrated,and the principles and methods of feedforward compensation and composite control based on the error function of the theoretical and practical models of speed regulation were elaborated.Finally,the system simulation was carried out,and at the same time,in order to verify the rationality and effectiveness of the adaptive feedforward compensation compound control strategy based on the dynamic theoretical model,the loading test was carried out on the servo system.The research results indicate that the proposed composite control strategy can accurately calculate the reference value and adjustment parameters for speed compensation of the servo motor,and the dynamic response speed of the system is improved by more than 78%compared to traditional closed-loop control algorithms.The adaptive ability and anti-interference performance of the system controller are also significantly superior to systems using traditional PI closed-loop control and fuzzy PI closed-loop control algorithms.By comparing and analyzing the sinusoidal response curves of 0.2 Hz and 0.5 Hz,it is found that the position tracking curve of this system has the best performance,the highest control accuracy,and the smallest error in the actual output value.