几何参数设计对相邻电容传感器性能的影响

Influence of Geometric Parameter Design on Performance of Capacitive Proximity Sensors

针对相邻电容传感器存在的测量信号微弱的问题,研究了相邻电容传感器的几何参数设计对传感器性能的具体影响,并通过几何参数的优化大幅度提高传感器测量性能.提出包括穿透深度、信号强度与噪声抑制、测量灵敏度与动态测量范围的相邻电容传感器性能综合评价细则.针对环形相邻电容传感器进行了极板几何面积变化对传感器性能影响的研究分析;设计了矩形、环形、交叉指形和螺旋盘形4种结构的相邻电容传感器,在等参数同测量环境下,对各相邻电容传感器分别进行电场仿真和边缘电容测量值比较,确定传感器几何形状对传感器性能的具体影响.实验结果表明,相邻电容传感器几何参数对传感器测量信号强度与测量灵敏度影响明显,复杂交叉指形与螺旋盘形的电容传感器测量区域的总体测量灵敏度比单结构的环形、矩形传感器的分别提高了66.8%与33.5%.

To deal with the weak signal strength in the measurement of capacitive proximity sensors, the effects of geometric parameter design were investigated,and the sensor measurement performance was greatly improved by the geometric parameter optimization. The comprehensive evaluation standards of sensor performance were presented, including penetration depth, signal strength and noise tolerance,measurement sensitivity and dynamic range. For round capacitive proximity sensors,the effects of the surface area on sensor performance were analyzed. Four different structures including rectangular,round,interdigital and spiral-shaped sensors were designed. In the same conditions,the electric field distributions of the sensors with four structures were simulated and the measured fringe capacitance was compared. The results indicate that the geometric parameters have remarkable influence on the measured signal strength and measurement sensitivity;comparing with rectangular and round sensors,the measurement sensitivity of interdigital and spiral-shaped sesnros was increased by 66 . 8% and 33 . 5%.