Terrain Compliance Control And Trajectory Tracking Of A Wheel-Legged Planetary Rover

Lunar/planetary exploration missions require the rover to be able to travel in challenging terrain.Intelligent,all terrain,large-scale inspection robot is the development trend of extraterrestrial planet exploration robot.The surface topography of extraterrestrial planets has the characteristics of irregularity,randomness of terrain strength,and soft soil.These unique environments bring challenges to the stability,security and trajectory tracking accuracy of planetary rover.It is necessary to solve the technical problems of high stability,low slip rate terrain compliance and high precision trajectory tracking of planetary rover in rough terrain.In this paper,the four-wheel-legged planetary rover is taken as the research object.Theoretical research and experimental verification have been carried out on the compliance control of the leg suspension system of the planetary rover,the wheel drive coordination and the three-dimensional trajectory tracking.In this paper,the motion control of a four wheel-legged planetary rover in irregular terrain is studied.The terrain compliance algorithm of the leg suspension system is proposed,based on the attitude adjustment kinematics and the leg suspension system impedance model,which can realize the compliance of the planetary rover to the geometric and mechanical characteristics of the terrain.A velocity mapping model between the driving wheel speed and the motion of the vehicle body and the leg suspension system is established.Based on Ackerman steering principle,a coordinated control algorithm of wheel speed under complex traveling mode in irregular terrain is proposed to realize the compliance of wheel speed to terrain.Based on the model predictive algorithm and PID control,a three-dimensional trajectory tracking controller for planetary rover is established,which can track the reference trajectory with high precision in irregular terrain.A joint simulation model of UG and Matlab/Simulink is established to verify the control algorithm.The software and hardware control system of wheellegged planetary rover is developed,and the control experiment is carried out to verify the effectiveness of terrain compliance control algorithm...