Design and Evaluation of Emergency Driving Support Using Motor Driven Power Steering and Differential Braking on a Virtual Test Track

This paper presents the design and evaluation of an emergency driving support (EDS) algorithm. The control objective is to assist driver's collision avoidance maneuver to overcome a hazardous situation. To support driver, electrically controllable chassis components such as motor driven power steering (MDPS) and differential braking and surrounding sensor systems such as radar and camera are used. The EDS algorithm is designed for 3 parts: monitoring, decision, and control. The proposed EDS algorithm recognizes a collision danger using minimum lateral acceleration to avoid collision and time-to-collision (TTC) and driver's intention using sensor systems. The control mode is determined using the indices from monitoring process and the collision avoidance trajectory is derived with trapezoidal acceleration profile (TAP). Using the collision avoidance trajectory, the MDPS overlay torque is determined to support the driver's response of collision avoidance and differential braking is determined to maximize minimum vehicle-to-vehicle distance. Vehicle behavior and the interactions between the vehicle, the controller, and the human driver are investigated through a full-scale driving simulator on the virtual test track (VTT) which consists of a real-time vehicle simulator, a visual animation engine, a visual display, and suitable human-vehicle interfaces. The success rate of collision avoidance is investigated with test drivers and it has been increased for all test drivers.