Automotive Adaptive Cruise Control System Signal Processing

With the development of highway's building in our country, the car-collision on highway takes place frequently, which brings numerous losses to the property of the country and the people. To avoid car from collisions on highway, adaptive cruise-control system is introduced in this paper. The condition of the road in front of the car can be kept watch on by this system continuously. Before the dangerous circumstance happen, a warning signal will be sent to the driver by the system in time, which can make the driver have enough time to take effective measures and avoid collisions. To complete the task of distance measurement, speed measurement, display, and warning, the theory of laser-based distance measurement is used in this system, and the system is controlled by SCM (Single Chip Microprocessor). Asynchronous serial communication between semiconductor laser range finder and SCM has been realized. The 8279 programmable keyboard/indicator interface chip has been adopted to design display module and keyboard. So the occupating coefficient of SCM is reduced and the respondence time of the system is enhanced. The part of software includes four program modulars and three subprograms. Data receiving, signal processing, keyboard design, distance or speed displaying, and alarming have been completed in this paper. This system can measure and show the distance between a car and barrier automatically. The range of the distance measured by this system is from 5 to 225 meters, and the precision is ±1 meter. This system can measure the relative relocity between a car and barrier automatically too. The range of the relative speed is from 0 to 150 km per hour. According to the warning threshold value of the distance, speed and relative relocity, the warning signal is provided when the relative distance reach the dangerous threshold value. The audible and light alarm signal or automatic brake order is provided when the relative distance reach the critical threshold value. According to relevant conditions, weather, road and his driving skill, the driver can set the warning threshold value. Compared with the actual request of the subject, this system extends the range of the measured distance and increases the precision of distance measuring. The developments of vehicle anti-collision technology in the world, the main...