Abstract
Rotational-speed measurement in harsh environments is an important topic. However, the high rotation results in rapid frequency variations in the signals of a sensor and changes in physical properties under extreme thermal circumstances cause significant difficulties in reading signals. To address this problem, we adopt wireless passive measurement methods to design a special characteristic signal circuit module that achieves precise measurement of rotational speed at high temperatures. The sensor and the readout system include a variable frequency source, a readout antenna, and a radio frequency demodulation circuit. Herein, a demodulation detector of the signal conversion circuit is designed and used in the envelope detection module of the single sideband demodulation method. In addition, a conversion circuit test platform for high-temperature environment sensor signal is developed. From the testing, the output signal demodulation of the sensor was observed under a maximum temperature of 700°C with error less than 0.12%. The new sensor and measurement method do not require physical leads and achieve wireless noncontact accurate measurement of rotational speed at high temperature.
Highlights
Rotational-speed sensors are widely used in aerospace, industrial control, traffic, and other fields, and the speed parameters in high-temperature environments are key for evaluating the working conditions of aero engines, space rocket engines, and ultra-high-speed turbo pumps [1,2,3,4,5]
Giebeler et al proposed a magnetic rotational sensors based on giant magnetoresistance (GMR) effect that were reliable at temperatures exceeding 170°C [6]
Magnetic materials degauss at high temperatures; GMR sensor is not suitable for high-temperature application
Summary
Rotational-speed sensors are widely used in aerospace, industrial control, traffic, and other fields, and the speed parameters in high-temperature environments are key for evaluating the working conditions of aero engines, space rocket engines, and ultra-high-speed turbo pumps [1,2,3,4,5]. Lin and Ding proposed a method that measures the rotational speed of the engine from the lowest harmonic frequency component of its vibration signals [10] This measurement method is simple and accurate, its high-temperature application is restricted. Autocorrelation algorithms can calculate the rotational speed based the image without a marker on the rotor; the measurement method has advantages such as noncontact measurement and high accuracy, its stability in harsh environments is limited. To accurately measure the rotational speed in a hightemperature environment whereas ensuring a significant response speed and stability of the sensor, we propose a wireless passive sensor with square coils and parallel capacitors manufactured using thick film integration technology and corresponding data readout system. The fabricated rotational-speed sensor is suitable for hightemperature applications, and the readout system fulfils the requirement of responding to rapidly changing signals in high rotational speed sensing applications, such as rotational speed detection
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
