Fixed-Time Sliding-Mode Lateral-Longitudinal Control for Vehicle Platoon With Strict Lane Constraints and Recoverable Spacing Policy

This paper investigates the lateral and longitudinal platoon control problem under user-specified lane and inter-vehicle spacing constraints. By modeling in the Frenét Frame, the lateral and longitudinal movements of the vehicles are decomposed. A novel lateral control strategy is proposed to strictly enforce a preset lane departure accuracy by transforming lane constraints into heading angle constraints. In the longitudinal control, considering the presence of a non-ideal leading vehicle, a prescribed performance controller is designed to regulate its velocity. Additionally, a longitudinal control strategy based on a double-ended smooth transition function is proposed to mitigate the effects of non-zero initial errors and restore the standard constant time headway policy after a preset time. To guarantee practical fixed-time stability, a continuous variable exponent coefficient fixed-time sliding surface is constructed, and adaptive sliding mode controllers are designed. The effectiveness of the proposed method is validated through both simulations and experiments. The source code is available on GitHub (https://github.com/Mudianrui/FSC-VPuLLC.git) to support further research on lateral-longitudinal platoon control.