Adaptive Robust Control for a Heterogeneous Vehicular Platoon

This paper presents an adaptive robust control approach for heterogeneous vehicular platoons subject to nonlinear and (possibly fast) time-varying uncertainty. The uncertainty is unknown and bounded. The vehicles in the platoon are modeled as nonlinear uncertain dynamic systems. To keep compact formation and guarantee collision avoidance, two-side inequality constraints are introduced for the spacing error between adjacent vehicles. A mathematical transformation scheme is proposed to convert the bounded state into an unbounded one. Based on backstepping method and Lyapunov stability theory, an adaptive robust controller is designed. A leakage type adaptive law is utilized to identify the bound of uncertainty. Furthermore, the controller renders the uniform boundedness and uniform ultimate boundedness performance for the unbounded state, which in turn guarantees the two-side restrictions for the spacing error. Finally, simulations are performed to illustrate the efficiency of the proposed algorithm.