Ultrasonic sensors are mainly developed based on the characteristics of ultrasonic waves. Ultrasonic waves are sent to the object through a wave transmitter, and the reflected wave is received by the wave receiver to detect the presence or absence of the object and the distance from the object. Calculate the distance between the sensor and the object by calculating the relationship between the time required from ultrasonic transmission to reception and the speed of sound. In addition, some machines detect the presence or absence of an object by detecting the attenuation or interruption of the ultrasonic waves generated by the object between the wave transmitter and the wave receiver. It can be seen that ultrasonic sensors can usually work when other types of sensors are insufficient, and ultrasonic sensors can detect objects that frustrate other types of sensors, and can work in some very clever situations.
Ultrasound is ideal for certain automotive applications. It is now used for blind spot detection and automatic parking in modern advanced driver assistance systems (ADAS). It has found its place in the open trunk/tailgate function of many new SUVs. These sensors are small enough and affordable, making them a good choice for new users.
Accurate measurement of liquid level is an important guarantee for realizing production process detection and real-time control, and it is also an important link in realizing safe production. In many places in my country, remote water level monitoring is required, such as factory reservoirs, reservoirs for farmland irrigation, water towers for water supply, and river water levels. It is very important to do a good job in remote monitoring of water level in these areas. The wide application of ultrasonic liquid level sensors benefits from simple structure, small size, low cost, simple and reliable information processing, easy miniaturization and integration, and real-time control. For the monitoring of remote water level monitoring system.
Many major automakers and technology companies are testing fully autonomous self-driving cars. Nissan and General Motors even stated that by 2020, they will test-run autonomous vehicles on the road. Both autonomous vehicles (and human-driving cars that incorporate driver assistance technology) extensively use sensors to monitor the road and surroundings. surroundings. For example, ultrasonic sensors can detect cars in adjacent lanes for "blind spot detection" and alert the driver when someone is in the blind spot.
Nowadays, microelectronic films, optical films, anti-oxidation films, giant magnetoresistance films, high-temperature superconducting films, etc. are continuously used in industrial production and human life. In the industrial production of films, the thickness is a very important parameter. It is related to whether the film material can work normally. Under normal circumstances, the thickness of the film refers to the distance between the surface of the substrate and the surface of the film, but in fact, the surface of the film is uneven and discontinuous, and there are pinholes, microcracks, filaments, impurities, and impurities in the film. Lattice defects and surface adsorption molecules, etc.
For example, various thin films in the production process of large-scale integrated circuits, due to the continuous improvement of the degree of circuit integration, any slight change in the thickness of the film will have a direct impact on the performance of the integrated circuit. In addition, the mechanical properties, light transmittance, magnetic properties, thermal conductivity, and surface structure of thin film materials are closely related to the thickness. Therefore, online accurate detection of film thickness in the production process is an important means to ensure product quality and improve production efficiency. At present, the film thickness measuring instrument has developed towards high precision and automation, and has reached a very high level. Its measurement accuracy is ±2%～±5% of the measured film thickness for general films, and ±2nm for relatively thin films. Micro area measurement function, fast measurement speed and high degree of automation. Especially with the advancement of science and technology and the application of precision instruments, in addition to the above-mentioned detection techniques, the method of measuring film thickness can also use ultrasonic sensors to detect film thickness.