柔性压力传感器阵列及其信号采集系统研究

Investigation on Flexible Pressure Sensor Array and Signal Acquisition System

为提高机器人人机交互的安全性,选用新型智能材料——电活性聚合物材料(Electroactive polymer,EAP)作为传感器阵列单元的敏感材料,设计一种4×4柔性压力传感器阵列及其信号采集系统。建立压力传感器输入输出数学模型,给出采用双三次插值法提高力觉信息量的方法,并制作了传感器试验样机,最后利用标定试验和应用试验验证了该传感器阵列的可行性、准确性和实用性。试验结果表明,设计的传感器电容理论值与测量值相差约0.01 pF,测量结果与理论结果吻合。在量程0~6 N内,最大灵敏度为0.1343 pF/N,重复性指标为28.73%。

In order to improve the safety of robot-human interaction,a new type of intelligent material named electroactive polymer(EAP)was chosen as the sensitive material of the sensor array unit,and a flexible pressure sensor array and its signal acquisition system were designed.The mathematical model of the input and output of the pressure sensor was presented and a method of increasing the force sensory information by using bicubic interpolation method was proposed.Furthermore,a prototype of the sensor based on VHB4910 was fabricated.Finally,the feasibility,accuracy and practicality of the sensor array were validated by calibration experiments and application experiments.The experimental results showed that the difference between the theoretical value and the measured value of the developed sensor capacitance was about 0.01 pF,the experimental results agreed well with the theoretical one.The maximum sensitivity was 0.1343 pF/N and in the range of 0~6 N,and the repeatability index was 28.73%.This tactile sensing display was flexible prone to stretch and had other excellent performance such as simple structure,good flexibility,easy to carry,and abrasion resistance.The tactile display had great application potential in case of safety of robot interaction,which can be used to test the surface contact force when the robot grasped some vulnerable objects such as eggs and strawberries.