Abstract: For the vehicle’s low efficiency,high emissions and high fuel consumption problem by idling operation at low vehicle speed in city driving,adopting idling start-stop system to save the fuel and reduce the emission of the city vehicle were studied.The controlling principle,electronic control unit and control strategy of engine idle start/stop system are elaborated,the dynamic model during engine starting process is constructed.Then the control strategy model for carrying out engine idle start/stop is built with Matlab/Simulink,and a co-simulation with Cruise software is carried out to conduct comparative analysis on the fuel consumption and emissions between the vehicle adopted by start/stop technology before and after in NEDC and Japan-mode urban driving-cycles.The simulation results show that the HC,CO and NO_x emissions of vehicle adopted by start/stop technology are declined obviously,fuel consumption adopted by start/stop technology is reduced significantly.The simulation results prove that the designed co-simulation platform and control strategy are feasibility and useful.It will have important theoretical significance for the development of vehicle start-stop control system.

Key words: vehicle, start/stop technology, cycling condition, co-simulation