Study of the Step Climbing Ability of a Rover with Rocker Bogie Mechanism

While the locomotion mechanisms of rovers have been widely studied, an attempt to find an optimum one has been hampered by the lack of standardization of a performance metric. This work studies the most commonly used rover locomotion mechanism, namely the rocker bogie, for its step climbing ability. Two modes of analysis were done, one in which the coefficient of friction between all wheels and the ground were same and another in which they were allowed to be different. Different optimum designs were obtained for different step heights. An analysis of these results showed that link lengths and wheel radii have a strong correlation with step height but the angles between the links have very little correlation. Overall, a rocker bogie based rover was found to be capable of climbing step heights between two and three times the wheel radius. The results give valuable insights into the relative importance of different design parameters of the rocker bogie for its step climbing ability and would aid in the evolution of its innovative variants.