电动静液作动器的高精度力反馈估计研究

High precision force feedback estimation on electro-hydrostatic actuator

静摩擦、齿隙和漏油会降低电动静液作动器反向驱动的性能,针对这一问题,对EHA模型进行了研究,提出了一种基于3种控制器组合的高精度力反馈估计方法。首先,通过使用反馈调制器来补偿静摩擦,并使用齿隙和漏油补偿器(不需要任何模型)来抑制电机侧和负载侧的相对速度;然后,提出了一种由压力传感器和编码器组成的力反馈观测器;最后,在由液压作动器和1自由度机械臂组成的实验装置上进行了实际测试。研究结果表明:相比于传统压力传感器,所提力反馈观测器获得的反作用扭矩均方根误差可降低3.34 N·m,可以十分精确地估计力反馈。

Aiming at the decrease of reverse drive performance caused by static friction,backlash and oil leakage on electro-hydrostatic actuator(EHA),a high-precision force feedback estimation method based on the combination of three controllers was proposed.Firstly,the static friction was compensated by a feedback modulator,and the relative speed between the motor side and the load side was suppressed by using a backlash and oil leakage compensator(without any model).Then,a force feedback observer composed of a pressure sensor and an encoder was proposed.Finally,the actual test was carried out on an experimental device composed of hydraulic actuator and 1-DOF mechanical arm.The research results show that comparing with the traditional pressure sensor,the RMS error of the reaction torque obtained by the force feedback observer of the traditional pressure sensor can be reduced by 3.31 N·m,and the force feedback can be estimated very accurately.