Influence of wheel-terrain parameters and multi-objective optimisation of wheel slippage for wheeled robots in rough terrain

Abstract

With the rapidly increasing applications of wheeled mobile robots in both planetary and terrestrial missions, more attention is being paid to autonomous navigation in rough and deformable terrain. Development of effective traction and motion control algorithms require good knowledge of the wheel-terrain parameters. This paper presents an analytical model and numerical simulation showing the influence of rotation angle ( θ ), sinkage ( z ) and wheel radius ( r ) on wheel slippage ( S ). It is found that as radius increases, slippage decreases until a certain optimum range 0.08 m to 0.18 m, after which increase in radius indicated no significant change in slippage. Sinkage and rotation angle increases as slippage increases. A multi-objective optimisation problem with slippage as the utility function is formulated and solved in MATLAB; the results reveal the optimal values of wheel radius, width, velocity, sinkage and rotation angle required to maintain optimum slippage and hence optimum traction in a dry sandy terrain.