A Novel Position-Based Impedance Control Method for Bionic Legged Robots’ HDU

IEEE Access

Zheng-Jie Gao¹  Xiang-Dong Kong¹  Guo-Liang Ma¹  Qi-Xin Zhu¹  Kai-Xian Ba²  Bin Yu² 

[1] Sch. of Mech. Eng., Yanshan Univ., Qinhuangdao, China;School of Mechanical Engineering, Yanshan University, Qinhuangdao, China;

关键词: Bionic legged robot;    hydraulic drive unit (HDU);    position-based impedance control;    active compliance control;    feedforward compensation control;   

DOI  :  10.1109/ACCESS.2018.2871244

来源: DOAJ

【 摘 要 】

In this paper, a novel impedance control method is designed for the hydraulic drive unit (HDU) equipped on the hydraulic driven legged robot. First, the position control mathematical model of HDU is built. Next, the HDU performance test platform is introduced and the performance requirements are given. Second, the system load pressure observer is designed and an accurate stiffness control method is proposed by combining the external load force feed forward control with the load force feedback control. Third, the damping control method based on the velocity feedback is designed. Finally, a novel impedance control method is proposed through combining the stiffness control and the damping control. The effects of all techniques listed above have been verified experimentally. Especially, the impedance control effects are verified by comparing the impedance characteristics with the natural characteristics of the secondorder mass-spring-damper system. This research indicates that the system characteristics of HDU with the novel impedance control method is well equivalent to that of the second-order mass-spring-damper system, which can solve the stall problem of the robot joint movement process caused by the load force vanish instantaneously and the switch between position control and force control. The above research can provide references for the active compliance control of bionic legged robots.

【 授权许可】

Unknown