Facilitating Fast Response of the Heterogeneous Vehicle Platoon Based on the Multi-Delay Proportional-Retarded Controller

For heterogeneous vehicle platoons, delays often severely impact the internal stability and string stability and reduce the response speed. To fully leverage the delays to improve platoon stability and facilitate fast response, this paper designs a proportional-retarded (PR) controller for the heterogeneous vehicle platoon by intentionally introducing multiple delays. Based on this, a feasible rightmost pole assignment method is proposed. Accordingly, the assignable range of the rightmost pole is determined by using the Cauchy-Riemann equation, and it is revealed that the assignable range is independent of the communication topology. Meanwhile, the guidelines for designing the controller parameters and delays are provided to facilitate fast response of the vehicle platoon. Moreover, to enhance the string stability progressively upstream along the platoon, the rightmost poles for each subsystem are reasonably separated by tuning multiple delays, and then the string stability conditions are derived. Finally, simulation results demonstrate the effectiveness and feasibility of the proposed method. Compared to the single-delay PR controller and traditional proportional-derivative (PD) controller, the heterogeneous vehicle platoon under the multi-delay PR controller exhibits a fast response, strong disturbance suppression capability, and significantly improved ride comfort and fuel economy.