An Investigation on Dynamic Signals of MFC and PVDF Sensors: Experimental Work

In the present paper, identification of dynamic sensing characteristics of macrofiber composite (MFC) and polyvinylidene fluoride (PVDF) is carried out via experimental investigation. As a first step, basic characteristics and operating principles of MFC and PVDF are briefly reviewed. Then, a clamped aluminum beam structure is prepared and experimental setup for vibration signal test is established with shaker system. Both MFC and PVDF are attached on the top and bottom surface of the beam structure, respectively, and connected to data acquisition system. In order to verify the operating bandwidth, frequency responses of the smart beam structure are obtained from 0 Hz to 5 kHz under sine sweep excitation. For the identification of dynamic sensing characteristics, experiments for linearity, durability, and robustness are conducted. It is observed that both MFC and PVDF have excellent sensing performance in measuring dynamic response and monitoring structural vibration

Reduction of the Radiating Sound of a Submerged Finite Cylindrical Shell Structure by Active Vibration Control

sensor

Wheel Slip Control of Vehicle ABS Using Piezoactuator-Based Valve System

This paper presents a novel piezoactuator-based valve for vehicle ABS. The piezoactuator located in one side of a rigid beam makes a displacement required to control the pressure at a flapper-nozzle of the pneumatic valve. In order to obtain the wide control range of the pressure, a pressure modulator comprised of dual-type cylinder and piston is proposed. The governing equation of the piezovalve system which consists of the proposed piezoactuator-based valve and the pressure modulator is obtained. The longitudinal vehicle dynamics and the wheel slip condition are then formulated. In order to evaluate the performance of the proposed piezovalve system from the viewpoint of the vehicle ABS, a sliding mode controller is designed for wheel slip control. The tracking control performances for the desired wheel slip rate are evaluated and the braking performances in terms of braking distance are then presented on different road conditions (dry asphalt, wet asphalt, and wet jennite). It is clearly shown that the desired wheel slip rate is well achieved and the braking distance and braking time can be significantly reduced by using the proposed piezovalve system associated with the slip rate controller