Wheel-terrain-obstacle interaction in vehicle mobility analysis

The currently undertaken study is to design an advanced wheel-leg system that provides optimal normal and traction force distributions among the drive wheels and improves vehicle dynamics/performance and provides mission fulfilment of an autonomous vehicle. This paper is a part of that study and deals with mathematical modelling initially of a wheel for both direct and oblique travel over an obstacle and proposes an analytical tool for (i) determining the obstacle height the wheel can overcome based on wheel-terrain-obstacle interaction, (ii) choosing the wheel radius to overcome the obstacle of given size, and later on the work is extended for (iii) determining the leg force in a wheel-leg combination, (iv) researching and proving a power mode of the wheel that has the ability to overcome the obstacle in a larger range for given wheel-terrain parameters and finally (v) determining the wheel torque in a bicycle model of a wheel-leg vehicle which can be incorporated in the control strategy for the distribution of wheel (motor) torque of an autonomous vehicle for its improved mobility.