基于AD7746的同面电极电容检测系统设计

Design of Uniplanar Electrode Capacitance Detection System Based on AD7746

同面多电极技术是一种新型的飞机复合材料构件异常检测技术,而实现同面电极电容的精确、稳定的测量是实现该技术的关键问题之一。本文以FPGA为核心,采用ADI公司推出24位高精度电容数字转换器AD7746,设计了同面电极电容检测系统,并给出系统的软硬件设计。实验结果表明:系统能够稳定测量出微小电容,可检测到复合材料实验样板0.2 mm厚度变化和8.6 mm检测深度。

Uniplanar multi-electrode technique is a novel detection technique of anomaly of composite components on aircraft,and accurate measurement of the uniplanar electrode capacitance is one of the key issues to implement the technique.In this paper,based on the 24 high-precision capacitance-to-digital converter AD7746 of ADI and FPGA,a uniplanar electrode capacitance detection system was designed.The design of software and hardware are presented.The experimental results show that the system can stably measure tiny capacitance accurately and detect 0.2mm thickness variation and 8.6mm depth range of the composite material experiment model.