Integral Sliding Mode Control Using a Disturbance Observer for Vehicle Platoons

A novel integral sliding mode control (ISMC) strategy, combining with a disturbance observer (DO) for vehicle-following systems, is presented in this article. The vehicle platoon includes a leading vehicle and multiple following vehicles subjected to unknown acceleration uncertainties. First, the ISMC based on DO and the constant time headway policy is constructed to realize the string stability of the whole vehicle platoon in a finite time, under the condition of zero initial spacing errors. The uncertainties of the vehicular system can be well estimated by extending DO even if the bounds of the uncertainties are not known exactly. In order to alleviate the chattering problem of the traditional ISMC, a continuous sliding surface including sign function is designed for the proposed ISMC strategy. Then, a modified constant time headway (MCTH) policy is proposed to overcome the requirement of zero initial spacing errors. In addition, the developed MCTH policy can effectively improve the string stability and safety of the vehicle platoon system. Finally, the effectiveness and advantages of the proposed algorithm are verified by the simulations and experiments.