Exploration of Vibration Signal Measurement Method of Automobile Parts Utilizing FPGA/Photoelectric Sensor

Abstract

According to the current situation of the sensor, a vibration signal monitoring system is proposed of automobile parts based on Field Programmable Gate Array (FPGA) and photoelectric sensor. FPGA controls the peripheral circuit and sets instructions to process the acquired vibration signal. The Serial Port Interface (SPI) is utilized for the data transmission and communication between the instruction set and FPGA. FPGA transmits the acquired data to the Digital Signal Processing (DSP) through the SPI and then backs up to the Secure Digital (SD) card for in-depth analysis. The Fiber Bragg Grating (FBG) is selected for the monitoring system. The sensor presents many characteristics: anti-interference, high sensitivity, lightweight, and small volume. Afterward, the FBG is used for vibration signal acquisition, and the corresponding sensor module circuit is designed. Subsequently, an Analog to Digital (A/D) conversion circuit is designed on the acquisition circuit together with the vibration conditioning circuit and FPGA peripheral circuit. In the experiment, the vibration signal is monitored in real-time through the designed monitoring system, and the changes in the Center Wavelength (CWL) of the FBG from vibration are recorded. The data are screened, and more reasonable data are produced for vibration signal processing. The vibration signal is processed through Time-Domain (TD) linear fitting and time-frequency transformation, to assess the FBG vibration sensor’s vibration response in the monitoring system.