Intelligent energy-saving control strategy for electric vehicle based on preceding vehicle movement

In the existing driver assistance systems of electric vehicle, the vehicular forward radar is mainly used for active safety control and seldom for energy-saving control. In order to improve the energy efficiency of electric vehicle, this paper proposes a novel energy-saving control strategy for electric vehicle based on movement of the preceding vehicle detected by forward radar. A hierarchical control architecture, which consists of three layers, is adopted in the proposed strategy. In the upper layer, the vehicles' relative motion state is classified into four different scenarios based on the assessment of driving safety. In the middle layer, the energy-saving mode decision and transition control strategy are designed according to the scenario classification. In the bottom layer, the motor's torque optimization and coordination control strategy are proposed to improve energy efficiency, while ensuring both driving safety and ride comfort. An optimized control algorithm based on Model Predictive Control (MPC) theory, is designed to optimize the motor's torque for each mode in real-time. Finally, our proposed energy-saving control strategy is applied to an electric bus. Simulation and experiment tests are carried out to verify the effectiveness of the designed energy-saving control strategy. The results show that the proposed strategy can significantly reduce the energy consumption of electric vehicle under urban road conditions. (C) 2019 Elsevier Ltd. All rights reserved.