电容式触觉传感器信号检测系统的设计

Design of Signal Detection System of Capacitive Tactile Sensor Array

信号检测系统对电容式触觉传感器的分辨力、稳定性和信噪比都有重要影响.设计了一种基于PCap01电容数字转换芯片的电容式触觉传感器的信号检测系统,采用FPGA控制多路开关选通电容式触觉传感器的触觉单元并进行阵列式扫描,通过SPI通信读取PCap01的测量结果后通过USB通信将数据传输给上位机,在上位机中以三维柱状图和曲面图动态显示电容式触觉传感器表面的受力情况,系统的采样速率可达15帧/秒.实验结果表明,设计的信号检测系统可以满足电容式触觉传感器的需求,通过采集的数据可以获取电容式触觉传感器表面的受力信息.

The resolution , stability , and signal noise ratio （ SNR ） of the capacitive tactile sensor array are influenced by the corresponding signal detection system .The signal detection system of a capacitive tactile sensor array is designed based on the commercial capacitance digital convertor （ CDC ） named PCap01 .The system proposed is mainly composed of a field-programmable gate array （ FPGA ） , a PCap01 and 6 multiplexers .After switching the row and column multiplexers sequentially by FPGA , the capacitance of each element of the tactile sensor is measured by PCap 01 .After all elements of the tactile sensor array are measured , FPGA transmits the data to host computer by frame .The result is displayed in 3D bar graph and surface graph in the host computer dynamically .The sampling frequency is up to 15 frames/s.Experiments show that the force distribution is obtained by the capacitive tactile sensor array and that the signal detection system meets the need of the tactile sensor .