Performance enhancement for a class saturating systems

This paper presents a systematic procedure for adapting a nominal controller, designed while ignoring control saturation, to higher-performance nonlinear controller that explicitly accounts for the saturating nonlinearities while guaranteeing stability. In particular, the error governor scheme proposed by Kapasouris, Athans, and Stein (1988) is extended for the class of controllers modeled with feedforward terms. The unity of this procedure is demonstrated on the vehicle platooning system introduces by Sheikholeslam and Desoer (1993), which uses a nonlinear vehicle model and allows for non-identical vehicles in the platoon. The nominal controller presented for this system is nonlinear and inherently decentralized, thus posing a significant test on the practicality of the proposed method. Performance of the nominal compensator without the saturations, nominal compensator with saturation, error governor, and extended error governor is compared for the platoon of 15 cars.