为了提高电液伺服阀的静、动态性能,采用压电叠堆执行器作为电液伺服阀的前置驱动级,提出了一种新型高速精密压电型电液伺服阀.针对系统的非线性和不确定性,提出一种改进的自调整函数模糊控制方法,将系统偏差和偏差变化量在同一闭区间内分成若干等级完成归一模糊量化,将调整因子变为调整函数,并对比例因子进行自调整,从而避免迟滞非线性带来的系统振荡问题,提高模糊控制器精度.实验结果表明,新型压电型电液伺服阀的静态迟滞环〈0.1%,分辨率优于0.03%,闭环控制时,幅频宽〉700 Hz.
To improve the static and dynamic performance of electro-hydraulic servo valve, a new type of highspeed and precise piezoelectric electro-hydraulic servo valve is developed. Muhilayer piezoelectric actuator is adopted as the electricity-machine converter of the proposed piezoelectric electro-hydraulic servo valve. Aimed at the nonlinearity and uncertainty of the system, a modified fuzzy control method involving adjusted function is proposed. The fuzzy quantification of error and the change of error are normalized in one region, then the selfadjusted factor is transformed into self-adjusted function, and the scale factor is self-adjusted. The control method can avoid the oscillation caused by hysteresis and improve the precision of fuzzy controller. Experimental resuits show that the hysteresis loop of the new type piezoelectric electro-hydraulic servo valve is less than 0. 1%, its resolution is less than 0. 03%, and the amplitude bandwidth of close loop control is greater than 700 Hz.