Multi-solution problem for track-terrain interaction dynamics and lumped soil parameter identification

A technique for identifying lumped soil parameters on-line while traversing with a tracked unmanned ground vehicle (UGV) on an unknown terrain is presented. This paper shows the multi-solution problem when identification of soil parameters - cohesion (c), shear deformation modulus (φ), and shear deformation modulus (K) are to be attempted using the track-terrain interaction dynamics model. The initiation of the idea of lumping the cohesion and internal friction angle terms and treating them as a single parameter to solve this problem is presented. The technique used for lumped soil parameter identification is based on the Newton Raphson method. This method is proved to be very effective in terms of prediction accuracy, computational speed, and robustness to initial conditions and noise. These identified lumped soil parameters can be used to increase the autonomy of a tracked UGV. The technique presented in this paper is general and can be applied to any tracked UGV.