Fault-tolerant control for automated highway systems

Increasing highway traffic congestion and real estate costs that limit the building of new highways has brought about a renewed interest in an automated highway system (AHS) where the vehicle steering task ("lateral control") and the braking/throttle tasks ("longitudinal control") are taken over by computers to increase the throughput of existing highways. Since safety plays a key role in the development of an AHS, fault-tolerant control is vital. In this paper, we develop a robust longitudinal sliding-mode control algorithm and prove that this control algorithm is stable for a certain class of faults. In addition, we show that intervehicle spacing errors will not become amplified along the AHS in the event of a loss of lead vehicle information. The performance of the sliding-mode controller is demonstrated through a series of simulations incorporating various vehicle and AHS faults.