A capacitive tactile probing system and the corresponding capacitance detecting system are developed to meet different measuring requirements. The principle of the probe and the capacitance sensor are illustrated. According to the measuring principle,the capacitance detecting circuit is the crucial component of the capacitive detecting system. Capacitance/digital converter(CDC) AD7747 chip is used in this circuit. The I C communication procedure between MCU and AD7747 and the serial communication between MCU and host computer are compiled to realize the detecting and handle the data. The performance of Z-axis is test simply. Through analysis of the experiment data, the resolution of the capacitive sensing probe system achieves 0. 02 μm and has a good repeatability. The possibility of the system is proved.%针对纳米尺寸测量领域的不同测量要求,尝试开发一种基于电容传感器的微触觉测头及其电容检测系统.阐述了测头的结构原理和电容传感器的工作原理,研制了基于电容传感器的微触觉测头.测头的测量原理表明:微小电容检测电路是整个电容检测系统的关键部分.该微小电容检测电路选用电容/数字转换器(CDC) AD7747芯片,分别编写了单片机与该芯片的I2C通信程序和单片机与上位机间的串行通信程序,实现了微小电容的采集和处理,简单进行了电容式传感测头的轴向性能的测试实验.实验表明:电容式微触觉测头的分辨率为0.02 μm,重复性较好,证实了此电容式微触觉测头的可行性.
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