Gait analysis and motion control of quadruped robot

LU Wei-li， BIAN Xin-gao， JIAO Jian， ZHU Deng-lin
（College of Mechanical & Electrical Engineering， Hohai University， Changzhou 213022， China）

Abstract： In order to achieve the stable walking of hydraulic pressure actuated quadruped walking robot，straight gait of the quadruped robot was planned by the principle of motion stability margin，and the stability margin was guaranteed for 100 millimeters when the robot's body was sustained by three legs. Aiming at the impact and shock of robot's body which were caused by the motion acceleration mutation of hydraulic cylinder，S-curve was presented and used as motion displacement control law of every degree of freedom. The virtual prototype model of JQRI00 quadruped walking robot was constructed by the structure. The simulation of the designed gait，the analysis of the gait's kinematics and dynamics characteristics and the displacement control method's motion characteristics were done using simulation software. The results of experiments which were done on the prototype of quadruped walking robot were compared with the simulations'. The results indicate that the designed gait is feasible， and it guarantees a good walking stability. Moreover，S-curve used as displacement control eliminates the acceleration mutation of hydraulic cylinder and makes the body more stable.
Key words： quadruped robot；gait planning；kinematics and dynamics analysis；S-curve