Distributed Integrated Sliding Mode Control for Vehicle Platoons Based on Disturbance Observer and Multi Power Reaching Law

In this article, a coupled sliding mode control (CSMC) is developed for vehicular systems with nonlinear uncertainties by using the disturbance observer (DO) and multi power reaching law. The DO is designed to estimate the nonlinear uncertainties. It is worth mentioning for the DO that the uncertainties include not only parameter uncertainty but also external disturbance, and the bounds of the uncertainties are not required to be known. In addition, the multi power reaching law is constructed to avoid the chattering problem of the traditional sliding mode control (SMC) and to improve the convergence speed effectively. Firstly, the constant time headway policy (CTHP) based on multi power reaching law and SMC is proposed to achieve the string stability for vehicle platoons. Compared with constant spacing policy (CSP), CTHP is more feasible in practice, because the desired spacing between adjacent vehicles is dependent on vehicle speed. Then, a modified constant time headway policy (MCTHP) is proposed for the vehicular systems to decrease the intervehicle spacing and increase the traffic density effectively. Finally, the numerical simulation and experiment are performed to demonstrate the effectiveness and advantage of the developed strategy.