String-stable automated steering in cooperative driving applications

The automation of vehicle steering is necessary in order to guarantee safe vehicle following in short-distance vehicle following applications. A necessary (safety) requirement for such automation strategy is lateral string stability. In this paper, a design for cooperative lateral controllers is proposed that yields a laterally string-stable platoon. The dynamics of the vehicles in the platoon are described using the dynamic bicycle model. The proposed controller is designed using the H_∞ control framework which achieves firstly, lateral string stability and, secondly, path-following, where the path is induced by the preceding vehicle in the platoon. Such control design approach is taken since it allows for the inclusion of the string-stability requirement as an a-priori design specification. The properties of the designed controller are evaluated by means of frequency domain analysis and numerical simulations and compared with a benchmark controller.