Research On Control Strategy Of Differential-braking-based Bus Dynamics Stability

With the rapid development of highway transportation and infrastructure，people onbus driving safety and handling stability have higher requirements. ESP(Electronic stabilityprogram) as a new active safety devices, is considered the most advanced form of anti-skiddevice. ESP can according to the operating conditions, road conditions and the driver actionsto control the vehicle, prevent the vehicle into an unstable condition, comprehensivelyimprove the driving safety and handing stability.This paper mainly studies the brake wheel selection and brake force distribution strategywhen the ESP controlling the bus. Firstly, the bus simulink model has been built for theresearch requirements, including the reference model, vehicle model, tire model and brakeforce distribution model. Then, through the analysis of different control strategies, threecontroller have been built. When the bus in the process of oversteer and understeer conditions,ESP can through controlling differential braking to choose right wheels, to generatingadditional yaw moment for balancing vehicle stability. Therefore, in order to maximizeexpansion of the stability of the vehicle wheel braking force control effect, this paperestablished single wheel brake and side wheel brake strategy with Stateflow software.Combined with the controllers in two kinds of typical operating conditions, to analysis thecontrol results, with single wheel brake strategy and side wheel brake strategy.The results show that the designed controllers in two different brake-selection strategiescan effectively lower the sideslip angle and yaw rate, ensuring a stable traveling state.However, with the increase of vehicle speed and the change of road conditions, the sidewheel brake strategy has higher efficiency and response rate.