Dynamic Modeling, Simulation and Velocity Control of Rocker-Bogie Rover for Space Exploration

Wheeled mobile rovers are being used in various missions for planetary surface exploration. In this paper a six-wheeled rover with rocker-bogie structure has been analyzed for planar case. The detailed kinematic model of the rover was built and the dynamic model was derived based on bond graph. The simulation studies were performed for obstacle climbing capability of the rover. It was observed from the study that rover can pass through plane surface, inclined surface, and inclined ditch without any control on the actuators of the rover. However, it fails to cross a vertical ditch so a velocity controller was designed. It consists of a proportional integral (PI) controller and reduced model of the rover. It is found from simulation and animation studies that with the proposed velocity controller the rover is able to cross the vertical ditch.