Abstract

In this study, a new integrated Nonlinear Tracking Control (NTC) is developed that includes the dynamic analysis of the hydraulic braking systems. In the developed algorithm, the desired set points for the slip values are iterated from a nonlinear tire model based on the Magic Formula. Simulations of hard braking and steering maneuvers are conducted using the nonlinear Yaw-plane Four-wheel steering vehicle model with Limited Roll motion (YFLR) incorporating the nonlinear Magic Formula tire model (MF). Similar maneuvers are applied to the same vehicle model that is equipped with the conventional PID controller. Braking and vehicle stability performances are compared for the two implemented control systems to verify the reliability of the proposed control. In this study, Four-wheel Steering Control (4WSC) and Variable Slip-ratio Control (VSC) are also developed along with the NTC in the YFLR model to assess the cornering characteristics of the vehicle during braking and turning. Three controllers are independent but are coupled through the states of the longitudinal and lateral tire forces. Considering the tire friction ellipse, the control systems are designed using model matching control method to impose the vehicle braking performances following a desired dynamic model even during large decelerations or lateral accelerations.