高分辨率电容式触觉传感器微电容检测系统设计

Design of a High-Resolution Capacitive Tactile Sensor Micro-Capacitor Detection System

摘要: 为了解决电容式触觉传感器在检测皮法至飞法级微小动态电容时，极易受长排线及环境寄生电容干扰而难以实现高精度信号捕获的问题，设计了一种基于FDC2214电容数字转换芯片的高分辨率微电容检测系统。该系统采用LC谐振原理将微小电容变化直接转换为数字信号，以抑制宽带噪声；同时在软件层引入静态基线差分校准算法与滑动平均滤波机制，剔除了系统固有寄生偏置与高频瞬态干扰。实验测试表明，在0.1~7.5 pF量程内，该系统示值波动稳定在0.004 pF以内，实现了柔性电容阵列的高精度信号提取。

Abstract: To solve the problem that capacitive tactile sensors are susceptible to parasitic capacitance from cables and environment when detecting minute dynamic capacitance at the picofarad to femtofarad level, making it difficult to capture signals with high precision, a high-resolution micro-capacitance detection system based on the FDC2214 capacitance-to-digital conversion chip is designed. The system adopts the LC resonance principle to directly convert minute capacitance changes into digital signals to suppress broadband noise. Meanwhile, a static baseline difference calibration algorithm and a sliding average filtering mechanism are introduced in the software layer to eliminate the inherent parasitic bias of the system and high-frequency transient interference. Experimental tests show that within the range of 0.1 to 7.5 pF, the measurement indication fluctuation of the system is stabilized within 0.004 pF, realizing high-precision signal extraction for flexible capacitive arrays.