Abstract: “A novel quadruped robot with special hybrid mechanism and hydraulic actuator is proposed in this paper. The feature of the robot is high power density and high reliability. It promotes the possibility of practical application of robots. The advantage of the hybrid mechanism is that it makes hydraulic actuators mounted on the torso intensively. This is benefit for adopting protective measures to prevent robots from nuclear, water and fire. The aim of this paper is to analyze the motion characteristics of the hybrid mechanism and to find out the inherent law of actuator designation with robot mechanism. The analysis results indicate that in a certain range the changes of step length have nothing to do with the maximum flow rate of actuators as long as the travel speed of robot remains constant, but the stroke of actuator changes with the step length. The Swing angle of actuator is very small, which is useful for extending hydraulic hose service life and improving robot reliability and sa”

Keywords: hydraulic, actuator, quadruped robot