What’s the multi-probe ultrasonic range finder

A multi-probe ultrasonic range finder for detecting traffic flow conditions, which not only provides information for traffic flow survey statistics and intersection traffic signal automatic control systems, but also applies to various automatic monitoring related to motor vehicle passing and arrival. In order to detect low-altitude flying targets, low-frequency remote active and passive sonar detection techniques have also been developed in the air, and the use of sound waves of several tens of Hertz can detect target signals thousands of kilometers. For example, there is now a newly developed anti-radiation missile that can track radar signals and destroy radar stations. In this case, low-altitude flight targets (armed helicopters) are measured to use passive sonar in the air. Positioning is appropriate. For another example, in order to prevent the radar from being discovered, the current cruise missiles are also flying very low. It may be about ten meters on the sea surface and may be several tens of meters on the land. At this time, the application of air sonar detection technology is also very effective. .In the field of ultrasonic technology, there are also some challenging frontier exploratory topics. Can I use two strong ultrasonic waves with slightly different frequencies 64KHz distance transducer sensor circuit, and use their nonlinear effects to make the low frequency different frequency signals propagate with the ultrasonic waves to obtain a difference frequency signal with strong directivity and slow decay. There is still a need for in-depth theoretical exploration and experimental verification. In order to develop ultrasonic ranging systems with low power consumption, small size, large range, wide frequency bandwidth and directivity, the physical properties of ultrasonic and piezoelectric materials, the mechanical structure of piezoelectric transducers, the mechanism and efficiency of electromechanical energy conversion , electromechanical impedance matching technology, ultrasonic transceiver circuit, ultrasonic ranging method and weak signal detection technology, etc., in the depth theoretical research and experimental verification. 

The main contents of each chapter in the thesis are briefly introduced as follows: The development status of automotive anti-collision system and vehicle ranging sensor in the past ten years is reviewed, and the development of large-range ultrasonic proximity sensors and large-range ultrasonic ranging systems are emphasized. Key technologies and application prospects briefly introduced the application of ultrasonic ranging and positioning technology in the automobile anti-collision warning system, mobile robot automatic navigation system and unmanned combat platform, and pointed out some frontiers in the field of acoustic theory and technology. The main task is to create a mathematical model of the cymbal transducer.The latest mathematical expressions of the radial-axial displacement transformation and the axial vibration mode of the cymbal transducer are derived. Theoretical calculations and test results show that although the model of the cymbal transducer is rough, the logic is correct and distinguishes the primary and secondary factors that affect the performance of the cymbal transducer.