Trajectory and Spline Generation for All-Wheel Steering Mobile Robots

Abstract

We present a method for trajectory generation for all-wheel steering mobile robots which can account for rough terrain and predictable vehicle dynamics and apply it to the problem of generating optimal motion splines. There has been little work in trajectory generation for vehicles with all-wheel steering capability compared to the Ackermann, differential-drive, or omnidirectional mobility system models. The presented method linearizes and inverts forward models of propulsion, suspension, and motion to minimize boundary state error given a parameterized set of controls. Our method for generating optimal motion splines between a set of state boundary constraints optimizes the free path heading boundary constraint while meeting position and orientation state constraints. We demonstrate this algorithm on the Rocky 8 rover platform, where parameterized linear velocity, curvature, and path heading controls are generated which satisfy position, orientation, and path heading constraints in rough terrain.