Speed control for automated highway vehicle under road gradient conditions

摘要

To increase the availability of automated highway vehicles with ACC systems in complex road conditions, such as gradient, curve, and some adverse weather like rain, fog and snow, this paper proposed a new intelligent speed control approach which considers the gradient road when a vehicle cruises. The vehicle longitudinal control system mainly incorporates throttle angle and brake torque as inputs and velocity of the vehicle as output. By regulating the velocity fitting in with the slopes of the road, several unnecessary actions of acceleration and brakes will be reduced, which improves driving safety and comfort. The vehicle longitudinal dynamics model is established, which contains traction force, aerodynamic force, rolling resistance and road slope. According to the desired slope of the road, it is considered the implementation of velocity tracking and reference velocity. The nonlinear properties of vehicle parameter uncertainties are considered together with road slopes. The vehicle control system is designed by using a Backstepping control method. The simulation results in a Matlab indication of the proposed speed control approach considering road gradients have good performance in speed tracking.