Single hydraulic actuator actively-compliant research based on the hydraulic quadruped robot

Abstract

When the robot appears, various researches on it have been coming out one after the other and changing rapidly. The robotics is refined day after day. Especially in the recent decades, with the emergence and developments of internet and the computers, it makes a remarkable progress and reaches an unprecedented level. The robot is of wide applications because of the rapid developments of robotics. Thus we make more requirements in all aspects of the robots. Compared to the wheeled robots, though the legged robot is lacking in speed efficiency, it's more suitable for practical applications for its high adaptability to environment as well as excellent flexibility in exercise. The overall performance of the quadruped robots is more outstanding that makes it a hot spot in the researches of every country. Then how to maintain the stability of the quadruped robot motion and adaptability to complex terrain, and improve the flexibility of the whole motion process at the same time? This has important significance to its design. For this reason, this paper designs a single drive unit of motion control system, which is based on hydraulic quadruped robot. This paper extracts a driver element from a robot with kinematics and dynamics of the strong coupling complex system and simplifies the analysis of the kinematics and dynamics. In addition, this paper introduces a force control unit and combines position and force control for a single driver element to solve the shortcoming of the existing pure position control stiffness is too large. The active compliance control introduced by this paper can guarantee position servo under the idle condition. This system can move compliantly according to impact size passivity, which is equivalent to reduce the stiffness of the system. Finally, this paper introduce the active compliance control method which is based on the original force and position hybrid control. Compared with the original force and position hybrid control, this method has better controllability and can achieve the ideal effect of flexible.