Sensors for Distance Measurement and Their Applications in Automobiles

Distance measurement under difficult environmental conditions is essential for automotive systems. Vehicles in the near future are intended to drive autonomously or at least to give the driver as much assistance as possible to increase safety and comfort. Distance measurement systems already exist that allow the implementation of systems such as collision warning and autonomous intelligent cruise control. The radar distance measurement used for this purpose works under arbitrary weather conditions, where other measurement principles such as laser, optical, infrared or ultrasonic systems may fail. Microwave radar is the most important measurement method for automotives. Ultrasonic systems serve as a parking aid. Other systems such as video-based systems are under development for autonomous driving within a lane. This chapter describes several distance measurement systems and their implementation in automobiles.