洞穴滴水传感器及其相关电路的研究与设计

Design and development of the cave dripping water sensor and its related circuit

精准了解洞穴滴水水文特征是研究喀斯特包气带地下水渗透过程的基础。为了连续准确获取滴水信息,本文研究设计了一个喀斯特溶洞洞顶滴水传感器以满足喀斯特水文地质研究中的需要。研究选择压电感应方式及PVDF压电薄膜作为感应材料,心音传感器作为感应元件。通过对扩充感应面的结构设计进行响应性原理分析,验证了三层设计会相互干涉,产生叠加信号并取得较好的感应效果。确定了顶层感应面材料和中间层材料。经过实验室模拟和洞穴实地观测,设计了传感器内部精准尺寸。信号处理电路和嵌入式系统软硬件的研发,实现了对传感器的长时间监测和记录。洞穴实地数据记录分析表明该传感器感应高度≥20 cm,最快速率10滴/s,具精准、稳定、防水的优点适用于洞穴高湿度环境中并满足相关研究工作的需要。

The accurate understanding of the hydrological characteristics of cave dripping water is the basis of studying the groundwater infiltration process in the karst vadose zone. To continuously and accurately obtain dripping water information, this paper designs a dripping water sensor of karst cave to meet the needs of karst hydrogeological study. The piezoelectric induction mode and PVDF piezoelectric film are selected as the induction material, and the heart sound sensor is used as the induction element. Through the analysis of the response principle of the structure design of the extended induction surface, it is verified that the three-layer design could interfere with each other, produce superposition signal and obtain good induction effect. The inductive surface materials of the top layer and the intermediate layer are determined. By simulation in the laboratory and field observation in cave, the precision size of the sensor is designed. The signal processing circuit, software and hardware of embedded system of the sensor are developed to realize the long time monitoring and recording. Cave field data analysis indicates that the induction height of sensor is ≥20 cm, the fastest rate of dripping water is 10 drops per second. It has advantages of precision, stability and waterproof. The sensor is suitable to high humidity cave environment and meets the needs of the related research works.