Anticollision system PRORETA with automatic braking and steering

Methods and experimental results of a collision-avoidance, driver-assistance system are described with automatic object detection, trajectory prediction, and track following, with controlled braking and steering. The objects are detected by a fusion of Light Detection and Ranging (LIDAR) scanning and video camera pictures that show the location, size and speed of objects in front of the car. A desired trajectory is calculated depending on the distance, the width of a swerving action and differential speed. For the trajectory control, different control methods were designed and tested experimentally, such as velocity-dependent linear feedback and feedforward control, nonlinear asymptotic output tracking and nonlinear flatness-based control, using extended one-track models with vehicle state estimation for the sideslip angle and cornering stiffness. Automatic braking is realised with an electrohydraulic brake and automatic steering with an active front steering. Various control systems are compared by simulations and real test drives showing the behaviour of a Volkswagen Golf with automatic braking and/or automatic swerving to a free lane, thus avoiding hitting a suddenly appearing obstacle. The research project PRORETA was a four-year cooperation between Continental Automotive Systems and Darmstadt University of Technology.