Trajectory Tracking Control of a Tracked Mobile Robot with a Passive Bio-Inspired Suspension

Abstract

A tracked mobile robot with a novel passive suspension system has been developed. The novel passive suspension system is constructed by using a bio-inspired animal-limb-like structure. A double layer nonlinear model predictive control (NMPC) architecture is adopted for the optimization of trajectory tracking. The upper layer NMPC is performed at a low frequency to optimize the global trajectory tracking performance, and the lower layer NMPC is performed at a high frequency to capture the local dynamics, like slippage and obstacle negotiation. An indoor environment experiment demonstrates that the novel passive suspension can efficiently absorb the strong shock induced by the process of obstacle crossing and hence guarantee the smooth motion and the double layer NMPC can effectively improve the trajectory tracking accuracy.