基于内环补偿的旋转液压弹性驱动器扭矩控制研究

Study of Torque Control of Rotating Hydro-elastic Actuator Based on Robust Internal-loop Compensator

液压驱动系统具有较高的功率质量比和耐久性特点,但由于系统非线性和高输出刚度,无法应用于交互式控制系统中,尤其是在机器人领域。提出一种力/力矩控制策略,设计了液压驱动器鲁棒内环补偿器(RIC),通过将内环补偿器与外环控制器解耦,将力/力矩控制问题简化为运动控制问题。提出连杆端运动反馈策略,采用扭转弹簧的交叉并联连接方式,建立了驱动器输出扭矩反馈控制器。对液压驱动器转角控制性能和HEA扭矩控制性能进行了试验验证,结果表明所设计的基于非线性鲁棒内环补偿器的HEA具有扭矩可控性、可反向驱动性和强鲁棒性。

Hydraulic drive system has high power-weight ratio and durability,but it cannot be used in interactive control system because of its non-linearity and high output stiffness,especially in the field of robots.A force/moment control strategy was proposed,and a robust internal-loop compensator(RIC)for hydraulic actuators was designed.By decoupling the internal-loop compensator and the outer-loop controller,the force/moment control problem was simplified to a motion control problem.A motion feedback strategy for the connecting rod end was proposed.The output torque feedback controller of the actuator was established by means of the cross-parallel connection of torsion springs.The experimental results show that the designed HEA based on the nonlinear robust inner loop compensator has the characteristics of torque controllability,reversible drive and strong robustness.