Identification of terrain mechanical parameters for a six-wheeled lunar rover

In future planetary exploration missions, the lunar rovers will be working in the incompletely known and uncultured environment, wheel-terrain interaction plays a critical role in rough-terrain mobility. In this paper an on-line estimation method that identifies wheel-ground contact angle and wheel slip from trajectory data using an extended Kalman filter is firstly presented. Secondly, the use of a suitable soil model can then allow key soil parameters to be estimated as the rover passes over the soil. Knowledge of the soil parameters may in turn be used to allow reference trajectories and control algorithms to be adjusted to suit the soil condition. Simulation and experiment results show that the terrain and control parameters algorithms can accurately and efficiently be identified for loose sand.