Trajectory Planning of Tracked Vehicles

This paper presents a method for computing the track forces and track speeds of planar tracked vehicles, required to follow a given path at specified speeds on horizontal and inclined planes. It is shown that the motions of a planar tracked vehicle are constrained by a velocity dependent nonholonomic constraint, derived from the force equation perpendicular to the tracks. This reduces the trajectory planning problem to determining the slip angle between the vehicle and the path tangent that satisfies the nonholonomic constraint along the entire path. Once the slip angle has been determined, the track forces are computed from the remaining equations of motion. Computing the slip angle is shown to be an initial boundary-value problem, formulated as a parameter optimization. This computational scheme is demonstrated numerically for a planar vehicle moving along circular paths on horizontal and inclined planes.