新型接近式柔性电涡流阵列传感器系统

NOVEL FLEXIBLE EDDY CURRENT ARRAY SENSOR SYSTEM FOR PROXIMITY SENSING

介绍了一种采用柔性印刷电路板工艺制作的新型接近式电涡流传感器阵列及其测试系统,以实现大面积曲面间微小间隙的实时监测。基于时分多路的扫描测试方法,对传感器阵列的设计方法、加工工艺及基底材料进行研究,设计了分叉式结构的线圈阵列及细长扁平引线电缆的柔性传感器探头。对传统的调频式振荡电路进行改进,解决线圈品质因数小的问题,提高了传感器系统的测试性能。试验结果表明,在2mm的量程范围内,传感器系统的测量精度优于±0.5％,适用于曲面间隙的在线监测。

Novel proximity eddy current sensor array and its testing system are developed to realize the real-time inspection of the small gaps between large curved surfaces. The flexible sensor probe, manufactured by the flexible printed circuit board （FPCB） process, is designed to consist of a forked coils array with a long flat cable by the investigations to the design, process and substrate materials for the eddy current array. The time division multiplexing （TDM） technology is introduced for the eddy current array to scan and sample all the sensor coils. Some reforms are implemented to the conventional oscillator to solve the problem of the coils having a low Q-factor and improve the performance of the sensor system. Experimental results show that the measurement accuracy of the sensor system can reach ±0.5% for a 2 mm full scale and the sensor system is suitable for online gap measurements.