Longitudinal vehicle dynamics using Simulink/Matlab

This paper examines the longitudinal dynamic model of a vehicle with automatic transmission. The modeling has been done in two stages: in the first stage the dynamics of power train consisting of the engine, the torque converter, the gear box, the final drive and the wheels are considered and in the second stage the effects of external forces exerted on the vehicle are added and overall effect is investigated, the external forces included in the model are: aerodynamic drag, gravitational effects, rolling resistance and longitudinal tire effects. The objective of this paper is to present the integrated Simulink model including the dynamic of powertrain and vehicle while considering the effect of the road on the longitudinal performance of the vehicle. Simulations are conducted using a set of traffic scenarios which are likely to occur in reality, the results obtained from the simulated cases and their effects on the performance of the vehicle are examined and reported. The results reported in this paper are part of an ongoing research investigation in the design of adaptive cruise control system.