Portable Design Of Detecting System For Magnetoelastic Resonance Sensors

Magnetoelastic(ME) sensor is a novel resonant sensor formed by the Fe-based amorphous alloy material. At an external alternating magnetic field, due to the magnetostrictive effect the sensor happen vibration,when the natural frequency of the sensor is consistent with the frequency of the alternating magnetic field, the resonance is produced, and the amplitude reached the maximum. The resonance frequency will change with the surrounding environment changes; such as the quality load, stress, viscosity etc. so by measuring the change of detection coil induced electromotive force to detect resonance characteristic of ME sensor. In the detection process, there is no electrical connection between the sensor and the detection device, therefore it is a wireless passive sensor, at the same time, the sensor also has the characteristics of low energy consumption, low cost, high sensitivity etc. Due to these advantages, the ME sensor has been widely used research of the fields of physics, biochemistry, biomedicine and so on. However, the current conventional ME sensor detection system is expensive, bulky, poor portability, high power consumption and Not long-term monitoring etc defects,which limits the application prospect of ME sensor.In view of the above problems, this paper presents a set of portable magnetoelastic sensor detection system design, Firstly, by analyzing the resonance model and detection principle of the ME sensor, The design idea of the detection method for the detection of the scan frequency was established, the portable design scheme which includes the power management unit, the micro controller unit, the AC drive unit, the data acquisition unit, the data storage and transmission unit, was designed. Meanwhile detection system specific design index was proposed.Then according to the design index, the low-power hardware design based on STM32 and the low-power control software design based on UCOS-II operating system was completed. Finally, the host computer software design of detection system was completed.After the completion of the detection system designs, then using Fe-based amorphous alloy strip 1k101 ME sensor completes system function, performance and practical test. which mainly includes the sensor response test experiment in the air, the sensor repeated test experiment, testing experiment of different media, system power consumption comparison test and detection system long-term monitoring usability testing, which includes the experiment of mass load test and the long time test of tap water corrosion sensor. The experimental results show that the detection system can realize the accurate detection of the resonance characteristics of the ME sensor, and it has good repeatability and reliability; the system can meet the test experiment in different environments. Compared with the traditional magneto elastic sensor detection system, the system has lower power consumption and smaller size. A portable low power ME sensor detection system design reference scheme is provided for the researchers.