Research On PVDF Intelligent Structure For Sensing Object Shape Characteristic Curve

Polyvinylidene Fluoride(PVDF)is a semi-crystalline homopolymer with piezoelectric effect and is a key component for making smart structures.PVDF film has the characteristics of high sensitivity,fast dynamic response,soft and easy to make into a suitable shape,which meets the requirements of intelligent structure production.Research on the development of the current shape sensing technology,the detection of the depth information of the object is particularly important for the reconstruction of the object shape curve.In this paper,the PVDF smart structure is designed for the sensing of the object’s topography curve,so as to realize the acquisition of the reconstructed coordinate points of the object’s topography curve.Based on the piezoelectric effect of PVDF materials,PVDF smart structure arrays with and without elastomer components were designed in the paper.I simulate the PVDF smart structure without elastomer components to obtain the error between the actual detection point coordinates and the theoretical point coordinates by simulation software.Due to its lack of depth information detection,the PVDF smart structure with elastomer components was modeled,fabricated and assembled,and the working principle of the smart structure was analyzed to establish the quantitative relationship between the voltage and the displacement of the sensing contact,and realize the acquisition of depth information.Under the condition of moving coordinate and global coordinate conversion,the NURBS curve method is used to reconstruct the shape curve of the obtained model value point coordinates,and the sine curve model is used to obtain the error generated by the curve reconstruction algorithm under the condition of different sampling numbers.Research has shown that there is an obvious quantitative relationship between the number of samples and the error of curve reconstruction,which provides a theoretical basis for selecting the best number of samples and reducing the reconstruction error.The experimental verification process first performs repeated pressing tests on a single PVDF smart structure,which verifies that the smart structure has good repeatability and dynamic response characteristics.Then the direct contact detection and sliding contact detection experiments were carried out on the PVDF smart structure array,and the acquisition program was designed by Lab VIEW software to obtain voltage information and MATLAB was used for curve reconstruction.Analyzing the goodness of agreement between the sensing curve and the original curve,it verified the feasibility of the designed intelligent structure for sensing the object shape curve.