Coordinated Control of Motor-Driven Power Steering Torque Overlay and Differential Braking for Emergency Driving Support

This paper describes a coordinated control of motor-driven power steering (MDPS) torque overlay and differential braking for emergency driving support (EDS). The coordinated control algorithm is designed to assist drivers to overcome hazardous situations. Electrically controllable MDPS and brake system are used as actuators, and a radar and a camera are used as a sensor system. Using environmental and vehicle information obtained from the sensor system, a risk of collision and driver´s intention are determined, and a collision avoidance trajectory is generated, incorporating the driver´s intention. Based on the generated collision avoidance trajectory, the MDPS overlay torque is determined to assist the driver´s speed of response, and differential braking is determined to maximize the minimum vehicle-to-vehicle distance to avoid collision. The performance of the proposed algorithm has been investigated via computer simulations and real-time (RT) human-in-the-loop simulations. The simulation studies show that the controlled vehicle can secure additional vehicle-to-vehicle distance in severe lane change maneuvering for collision avoidance. The success rate of collision avoidance has been investigated for eight test drivers using the human-in-the-loop simulations. It has been shown that most of the test drivers can benefit from the proposed support system.