Real-time Gait Planning And Control Algorithm Design Of Quadruped Robot Based On Foot-touch Driving

Taking MIT Cheetah Mini quadruped robot as the reference object,this paper makes a quadruped robot with full knee series leg structure,designs a real-time gait planning and control algorithm based on foot-touch driving,and establishes the foot touch finite state machine of quadruped robot,which effectively improves the stability of the quadruped robot when it passes through uneven terrain.According to the mechanical structure of the quadruped robot,the kinematics forward and inverse solution equations are solved,and then the description method and several typical gait forms of the quadruped robot in the flat environment are analyzed,and focusing on the walk and trot gait;the polynomial curve fitting method is used to fit the foot end trajectory of the quadruped robot to meet the requirements of stable walking;the motion characteristics of the quadruped robot walking in Walk and Trot gait and the stability of the robot walking in the flat environment are verified by simulation experiments.Through the motion analysis of the quadruped robot in the uneven terrain,the leg states of the robot are divided into three cases: early contact,delayed contact and normal contact,and the finite state machine of foot contact is established.According to the situation of early contact and delayed contact,the method of re-planning the swing phase trajectory by Bezier curve is adopted.According to the change of terrain,the gait of quadruped robot is planned in real time,which reduces the impact force at the moment when the quadruped robot touches the ground and improves the stability of the body.Finally,the visual simulation of the algorithm is carried out by programming in MATLAB and Vrep simulation platform.The simulation results show that the motion control algorithm can effectively reduce the impact force at the moment when the robot's foot touches the ground and improve the stability of the body when the quadruped robot passes through the uneven terrain with obstacles in Walk and Trot gait.In addition,the quadruped robot can re-plan the new swing phase trajectory with the different position of the obstacle block,which shows good adaptability to the uncertainty of the terrain.