Ultrasonic sensors form the principle of ultrasonic waves

     Ultrasonic sensor is a device that can transmit and receive ultrasonic waves to achieve ranging, detecting object placement and detecting object properties. It mainly measures the distance of the target object by transmitting and receiving ultrasonic waves.

     The principle of the generation of ultrasonic waves is based on the piezoelectric effect, that is, the piezoelectric material will deform and generate electric charges when subjected to external forces. Ultrasonic sensors usually use piezoelectric materials (such as quartz crystals or ceramic materials) as sound sources. When an alternating voltage is applied to a piezoelectric material, the material contracts and expands periodically, resulting in high-frequency vibrations.

     The periodic vibrations generated by the CD4042BE piezoelectric crystal or ceramic sheet in the sensor propagate through the medium, forming an ultrasonic wave. The ultrasonic frequency is usually between 20kHz and 200kHz, and the ultrasonic sensor can choose the appropriate operating frequency according to different application requirements.

     Ultrasonic sensors have both transmitting and receiving functions. When the ultrasonic sensor emits the ultrasonic wave, the ultrasonic wave will spread around and reflect when it encounters an obstacle. The reflected ultrasonic waves are picked up by the sensor's receiver and converted into electrical signals.

     Piezoelectric materials are also commonly used as the base in the receiver, and when the ultrasonic wave reaches a low vertex, it creates a mechanical strain, which excites the piezoelectric material to produce an electric charge. After these electrical signals are amplified and filtered, they are converted into digital signals and sent to the control system for analysis and processing.

     Based on the speed of the ultrasonic wave propagating through the air and the time difference required for the ultrasonic wave from transmission to reception, the distance between the target object and the sensor can be calculated. Through multiple measurements and tracking, it is possible to detect and track the placement of target objects.

     It should be noted that the ultrasonic sensor has a certain impact on the nature of the target object. Different materials have different absorption, reflection and propagation rates of ultrasonic waves, so it is necessary to select the appropriate ultrasonic sensor according to the needs of the application and the characteristics of the target object.

     In short, ultrasonic sensors generate ultrasonic waves through piezoelectric materials and use the propagation characteristics of ultrasonic waves in the air to achieve the function of measuring the distance of the target object. The principle has been widely used in industrial automation, unmanned vehicles, medical equipment and other fields.