Selection of Ultrasonic Sensors for Distance Monitoring

This article analyzes the influence of the characteristics of ultrasonic transducers on the performance of a measuring system using ultrasonic sensors to monitor the position of the moving part of the equipment and control the whole process. The purpose of the analysis is to optimize the control protocol scheme. Ultrasonic transducers are used as a transmitter and receiver of ultrasonic vibrations, the main structural element of which are piezoelectric elements. The physical principle of the piezoelectric element action is stated. Selecting an ultrasonic transducer, the following pairs were tested, including a transmitter and a receiver: AW8R40-10OA00 / AW8T40-10OA00, AW8R40-12OA01 / AW8T40-12OA01 (manufacturer AUDIOWELL), TCT40-10R1 / TCT40-10T1 (manufacturer MEC) and UCE10T-40R-WA / UCE10T-40T-WA. All of them have a resonant frequency of 40 kHz. The transducer characteristics such as sound pressure level SPL, sensitivity, bandwidth, divergence angle, capacitance, maximum applied voltage, operating temperatures are considered. The methods of analysis are proposed and the study of the influence on the functional work of the circuit of the following factors is conducted: frequency; the number of pulses of the generator; distance from source to receiver; angular displacement transducers. The results obtained from the test make it possible to develop recommendations for the selection of ultrasonic transducers to be used as a part of a displacement sensor and optimize their operation. The displacement sensor based on ultrasonic transducers was tested in the PIKA-19 set of equipment for static sensing, manufactured by the PIKA-TECHNOSERVICE Scientific and Technical Center LLC.