Multiple applications of ultrasonic distance measuring sensor

Ultrasonic waves have beam and reflection characteristics, which can basically travel along a straight line, and their energy is much larger than the low frequency sound waves of the same amplitude. The non-contact ultrasonic ranging sensor is made by using this characteristic of ultrasonic waves. In air media, the performance of ultrasonic distance measuring sensors is almost independent of light, dust, smoke, electromagnetic interference and toxic gases, and is inexpensive and easy to use. Therefore, ultrasonic ranging sensors have been widely used in many fields such as level measurement, vehicle safety driving assistance system, robotic automatic navigation, combat platform, terrain detection, and even river level monitoring. In addition, since ultrasonic waves are farther away than electromagnetic waves and ultrasonic waves .which are widely used as information carriers in the underwater target detection, identification, positioning, communication and navigation, and offshore oil development. in this end, in the depth study of the generation and propagation of ultrasonic waves, the development of high performance ultrasonic transducer, and the exploration of new ultrasonic signal processing methods are of great practical significance for promoting the development of ultrasonic transducer technology and ultrasonic technology.

With the increasing number of cars in the world, vehicle collision accidents have been increased, especially in urban roads and traffic accidents on the expressway are increasing day by day. Adaptive vehicle anti-collision technology and automotive anti-collision warning system is related for ranging technology , and ultrasonic transducer distance sensor circuit has become a hot research topic in the field of vehicle engineering and measurement control technology.

In the past ten years, the anti-collision devices developed by European and American automobile companies have been tend to use millimeter wave radar as the vehicle front-facing distance measuring sensor.because the millimeter-wave radar can detect distant objects, so that the on-board controller has enough time to process and utilize the sensing information to prevent the vehicle from colliding with the obstacle . However, more collision accidents occur at the moment when the vehicle changes lanes, turns or reverses, and ultrasonic distance range transducer is not limited to the vehicle moving forward at high speed. This requires the car's active anti-collision system to have the basic function of identifying objects surrounding the vehicle, predicting danger in advance, or automatically maintaining a safe driving distance. 

Since the common ultrasonic ranging sensor has a short acting distance, it can only be used to detect close range targets (such as ultrasonic probes in the parking or reverse collision warning devices), and is not suitable for detecting surrounding objects close to the vehicle (greater than 15m).To this end, some well-known car companies are planning to install a short-range radar on the car, which can detect up to 8 objects within 20m of the vehicle. This additional acquiring condition can be used to activate the vehicle anti-collision system, estimating the relative distance and speed of the vehicle and surrounding objects in real time to determine whether there is a traffic accident risk, and issue a warning or take necessary emergency measurement in time to avoid vehicle collisions or mitigate the consequences of vehicle collisions. However, the price of short-range radar is expensive, which limits its promotion and application in ordinary cars. Therefore, the development of cost-effective ultrasonic transducer sensor and target detection systems must promote the development and universal application of automotive anti-collision systems with all-round detection. At the same time, this technology can also be applied to the automatic target recognition system for combat platforms or field robots.