Pvdf Low-frequency Ultra-low Frequency Accelerometer-based Study

Low-frequency and ultra-low frequency is a common physical phenomenon, widely exist in a variety of mechanical device, processing process and large construction structures. This vibration has a low frequency, the complex components below 1Hz frequency, and undermining strong characteristics. So caused great damage to the production and life, while the ultra-low-frequency and low frequency measurements do not success at internal and abroad. Therefore, in this paper according with this situation, a new type of piezoelectric accelerometer design concepts and methods based on PVDF has put up after studying the existing piezoelectric acceleration sensor.PVDF (polyvinylidene fluoride) is a new type of high polymer-based sensor material. The sensor based on the PVDF has the advantages of a piezoelectric properties, high sensibility, low acoustic impedance, wide frequency response, ability of being easily placed and resistance of corrosion,and so on.In this paper, according to the PVDF sensitive element, the equivalent model sensing equations for PVDF piezoelectric films are explored and a theoretical basis for the design of the sensor sensitive element are provided.Analysis and established a mathematical model of the accelerometer and transfer function. And its frequency response characteristics are analyzed. Study the structural features of traditional sensors, proposed a new sensor structure, and the various parts of its structure, including sensitive components, flexible components and inertial components, are detailed model and analysis of their characteristics.In addition, design the sensor size of various parts of the specific parameters, discuss the sensor constraints between natural frequency and sensitivity and produce the sensor in-kind. Compared with the standard sensor to study the characteristics of the tested sensor, including: voltage sensitivity, frequency response characteristics and the voltage sensitivity of the non-linear characteristics and so on, and determine the frequency of the sensor scope of work.Finally, further research directions with it are briefly discussed.