电动静液作动器双惯性建模与高精度位置响应研究

Double inertia modeling and high precision position response of electro-hydrostatic actuator

非线性的摩擦会使电动静液作动器产生严重的谐振问题,为此,在对电动静液作动器进行双惯性系统建模的基础上,提出了一种电动静液作动器的谐振比控制方法。首先,分析了电动静液作动器的工作原理,并通过采用由一个低刚度轴连接的两个高刚度惯性体,对电动静液作动器进行了双惯性系统建模;然后,通过采用反馈调制器对作动器静摩擦进行了补偿,并在参数辨识的基础上设计了一种包含反馈控制器和干扰观测器的谐振比控制方法,有效抑制了作动器的振动;最后,在单连杆机械臂实验装置上进行了频率响应和位置响应测试。研究结果表明:电动静液作动器频率响应曲线中观测到的双谐振现象验证了双惯性系统建模的可行性;相比于其他两种常规的比例积分控制方法,该谐振比控制方法的最大超调量仅为0.035 rad,平均响应误差仅为0.005 rad,具有更高精度的位置响应控制性能,在液压传动研究领域中具有较好的参考价值和应用前景。

Aiming at the serious resonance problem of the electro-hydrostatic actuator caused by nonlinear friction,the electro-hydrostatic actuator was modeled as a dual inertial system and a resonance ratio control method was designed.Firstly,the working principle of the electro-hydrostatic actuator was studied,and the electro-hydrostatic actuator was modeled as a dual inertial system by using two high-stiffness inertial bodies connected by a low-stiffness shaft.Then,a feedback modulator was used to compensate the static friction of the actuator,and a resonance ratio control method including a feedback controller and an interference observer was designed based on parameter identification,which effectively suppressed the vibration of the actuator.Finally,the frequency response and position response were tested on a single-link manipulator experimental device.The results show that the double resonance phenomenon observed in the frequency response curve of electro-hydrostatic actuator verifies the feasibility of the proposed dual inertial system modeling.In addition,compared with the other two conventional proportional-integral control methods,the maximum overshoot of the proposed resonant ratio control method is only 0.035 rad,and the average response error is only 0.005 rad,thus obtaining high-precision position response control performance,which having good reference value and application prospect in the research field of hydraulic transmission.