Research On PVDF Displacement Sensor And Its Application

This paper presents choice,manufacturing,installation,modeling of Polyvinylidene Fluoride(PVDF) displacement sensor using on Ionic Exchange Polymer Metal Composites(IPMC) actuator of bionic robot fish and intelligent measurement and control system integrated PVDF sensor/IPMC actuator.This paper is based on the application of bionic robot fish.A stable sensor is selected and used to monitor the driving state of actuator real-timely for conquering the uncertainties existing in actual engineering systems and the possibly problems of IPMC instability,such as easy to become fatigue caused by the long time use.Besides,appropriate control algorithm is also adopted to achieve closed-loop control that is the ideal way.PVDF piezoelectric films are the most potential organic polymer material that are soft,thin light,and have advantages of high toughness,high sensitivity,fast response,wide frequency range and high chemical stability.These good performances make them extensive promotion as new intelligent sensors and be also the optimum flexible sensors for using on the IPMC actuators.This paper presents the manufacture of PVDF sensors,and adopts a kind of convenient packaging technology that can ensure the inherent flexibility and sensitivity of PVDF sensors,and greatly improve the waterproof and insulated performance.What's more,this kind of packaging technology can also avoid short circuit and electric leakage.In this paper,the installation method is an innovative point.In most applications based on PVDF sensors,PVDF sensors are often pasted on the surface of object or embedded in the tested object.In this paper,through a large number of comparative experiments,a new parallel installation is given that can effectively avoid the effects caused by some limitations of IPMC actuators and make the sensor and the actuator play the best performances.The feasibility of PVDF sensors is analysed by a large number of experiments.The comparative analysis between PVDF sensitivity and IPMC own sensitivity is presented which shows the advantages of using PVDF sensor in this research.Then,the theoretical model of PVDF sensors with cantilever structure is given which provides an important basis for determining the final size of the sensor,and solves the problem of big error caused by large deformation.What's more,it is the necessary function of the final closed-loop control.Finally,combining with the PI control algorithm and LabVIEW software,the closed-loop control is achieved.The PI controller can control and adjust the driving state of the actuator real-timely in the range of allowed error.Long-term stable operation of the bionic robot fish can be ensured.