Design and Validation of Differential Braking Controllers for Sport Utility Vehicles Considering the Interactions of Driver and Control System

This paper introduces the design and validation of a differential braking controller for sport utility vehicles (SUVs) with driver-in-the-loop real-time simulations. SUVs are designed with high ground clearance, which is a main reason for their high rollover rate. A nonlinear 3 degrees-of-freedom (DOF) SUV model is generated to design a differential braking controller. The desired states are determined using a 2-DOF bicycle model and the lane-keeping control results derived from vehicle velocity and road curvature. The actual vehicle states of the 3-DOF model may deviate from the desired ones. A sliding model controller (SMC) is designed to minimize the state error to improve the performance measures, e.g., yaw stability. The SMC controller designed in LabVIEW is integrated with a virtual SUV generated in CarSim for cosimulations. The controller is first examined in the emulated sine-with-dwell maneuver specified in FMVSS 126. The SUV performance depends not only on the control strategy, but also on its interaction with the human driver. To study the interaction of the driver and the controller, the overall system is simulated using driver-software-in-the-loop (DSIL) realtime simulations under a double-line-change (DLC) maneuver. The simulations show that, even equipped with the electronic stability control (ESC) system, the driver still plays an important role in the vehicle dynamics. The simulations demonstrate the effectiveness of the proposed differential braking controller, and the research discloses important interactions of driver and ESC system.