Modelling the longitudinal braking dynamics for heavy-duty vehicles

This paper establishes a reliable heavy-duty braking system model that can be used for response time prediction and for vehicle braking calculations regarding the legislative requirements. For the response time prediction, a pneumatic system model of a heavy-duty vehicle is constructed by Matlab Simulink in consideration of service brake layout. To ensure the accuracy of system parameters related with pneumatic system response time experiments are conducted on two different 4 x 4 heavy-duty vehicles. The numerically calculated response time results are validated with experimental data. To improve the response time of the vehicle, design modifications are conducted on the pneumatic brake system properties. To check the compliance of the pneumatic brake system design with legislative requirements of UN Regulation 13, heavy-duty vehicle brake system (HVBS) model is developed by using Matlab Simulink. HVBS model is composed of longitudinal vehicle and wheel dynamics, Magic Formula tyre model, wheel slip and the experimentally verified heavy-duty pneumatic system model. The braking performance analyses are conducted by using HVBS model to compare the design alternatives in accordance with the legal requirements in terms of service braking and secondary braking conditions