Application Of Laser Ranging Sensor In Automotive Radar System

Application of Laser Ranging Sensor in Automotive Radar System

At present, the ranging methods used in automobiles mainly include ultrasonic short-distance ranging, millimeter-wave radar long-distance ranging, laser ranging, and camera system ranging. 1 Ultrasonic distance measurement It uses the principle of ultrasonic detection to correctly understand the distance between the tail of the car and the obstacle when the driver reverses the vehicle. When the distance display is smaller than the alarm distance, it can also accurately alarm and prompt the driver to brake. Ultrasonic generally refers to mechanical waves with a frequency above 20 kHz. It has the characteristics of strong penetrability, small attenuation and strong reflection ability. Ultrasonic ranging instruments generally consist of a transmitter, a receiver and a signal processing device. In operation, the ultrasonic transmitter continuously emits a series of continuous pulses and provides a short pulse to the measurement logic. The ultrasonic receiver also provides a short pulse to the measurement logic after receiving the reflected wave reflected by the obstacle. The received signal is processed by the signal processing device according to the time difference, and the distance between the vehicle and the obstacle is automatically calculated. The principle of ultrasonic ranging is simple, the cost is low, and the production is convenient. However, its application in high-speed vehicles has certain limitations. This is because the transmission speed of ultrasonic waves is greatly affected by the weather, and the propagation speed is different under different weather conditions. On the other hand, for obstacles at a long distance, since the reflected wave is too weak, the sensitivity is lowered. Therefore, ultrasonic ranging is generally applied to short-distance ranging, with a distance of 4 to 5 meters, and is generally applied to a car reversing collision avoidance system. 2mm Wave Radar Long-Range Ranging In order to better adapt to road traffic conditions and solve the blind spot vision problem, a lot of work has been done in Japan and the United States. For example, the millimeter-wave radar CCD camera is used to detect the traffic condition, and the tone, color and position of the intuitive signal are changed according to the degree of danger, and displayed in the display. Achieve high intelligence and greatly improve the safety of vehicles.