Research On Array-type Flexible Tactile Sensor Based On The Principle Of Capacitance

The tactile sensor is an important means to identify environmental information such as object characteristics and the surface information of the object.In recent years,its application in medical equipment,intelligent robots,health monitoring and other fields has become a research hotspot for scientific researchers in various countries.In this paper,it has analyzed the research status of tactile sensor at domestic and overseas.In view of the problems of poor flexibility,complex structure and processing technology and the difficulty in achieving large area application existing in flexible tactile sensor,a array-type flexible tactile sensor is designed to be used in the field of medical detection and intelligent robot on the basis of the polymer composite.The sensor has the advantages of low cost,easy processing,good flexibility,large array area and flexible folding.This paper introduces the structure and working principle of the array-type flexible tactile sensor,designs the array mode of sensor unit.The sensor array is composed of topelectrode layer,bottom-electrode layer and intermediate dielectric layer.Each electrode layer has a plurality of parallel strip electrodes.The top layer and bottom layer electrodes are perpendicular to each other,which crossing point form the sensor array cell.Conductive rubber is used as the electrode material.And the influence of different carbon black content on the conductive properties of conductive rubber was analyzed.Polyurethane foam is used as dielectric layer material.And the properties of polyurethane foam were analyzed.The effect of different polyurethane foam on the output performance of the sensor was studied.And the capacitance frequency characteristic of tactile sensor array cell was analyzed.According to the characteristics of the flexible tactile sensor array proposed in this paper,the signal collecting and processing system is designed.The principle of signal acquisition of tactile sensor was analyzed.In this paper,multi-line scanning method is proposed to improve rate of the signal collecting system.The signal acquisition hardware system of the array-type flexible tactile sensor is designed.And the software system of tactile sensor signal acquisition is developed,realizing the collection of tactile sensing information.Then,the data is presented graphically in the upper computer software interface after processed by the method of filtering and interpolation.After the performance test experiment of array-type flexible tactile sensor and human sleeping position detection experiment,the results show that the flexible tactile sensor array and its signal collecting system proposed in this paper has good sensitivity and accuracy.The multi-point scanning method improves the signal collection speed and makes it achieves the real-time display of the contour and pressure distribution of the measured object.The experimental results show that the sensor has good tactile sensing function,which can be used in the field of medical detection and intelligent robot.