面向足式机器人的P-Q阀控非对称液压缸位置闭环刚度特性研究

Research on the Stiffness of Closed Location Loop of Single-rod Cylinder with the P-Q Valve Used on the Legged-robot

大负载足式机器人一般选用液压驱动单元作为系统的驱动机构。考虑到机器人结构紧凑性及控制性能等原因,研究了一种基于P-Q阀控非对称液压缸系统的位置闭环刚度特性。通过建立并利用系统的非线性方程,结合P-Q阀的特性,研究了P-Q阀在位置闭环时等效刚度动静态特性。研究表明,在位置闭环时,系统特性与弹簧等效且等效刚度与系统的增益成正比,这为机器人基于位置闭环的阻抗控制提供了理论基础。

Robots that work in the wild environment with heavy load usually use a hydraulic system as its actuator.Considering the structure and control characteristic of the robot,the characteristic of single-rod hydraulic system on P-Q valve is studied.By establishing and using the system＇s nonlinear model and with the characteristic of the P-Q valve in mind,this paper analyzes the closed position loop stiffness of the system.The result shows that the equivalent stiffness is proportional to the gain of the system when the system is in closed loop condition with external force disturbance and this provides a theoretical basis for the control of the legged robot and the analysis of the characteristic of the robot.