Application of FBG sensor for vibration measurement in wheel bench test of automobile

Abstract

Vibration measurements of a road-wheel were demonstrated using a fiber Bragg grating sensor (FBG sensor) and a flat-belt test machinery. Davis and Kersey's method to measure Bragg wavelength of an FBG sensor was applied in the tests. An assembled wheel of a tire and a road-wheel for an automobile was set on the machinery. When the flat-belt ran at the velocities of 10～200 km/h, the belt rotated the wheel at the velocities of the belt. The vertical load between the wheel and the belt was loaded by weights of 400 kg. An FBG sensor was attached to the back surface of the road wheel to measure radial vibrations of the wheel. The Bragg wavelength changes without the 0-Hz elements possessed almost the same waveforms against the non-dimensional time by the 1-cycle period under different velocity conditions of the flat-belt running. The waveforms show two peaks in the longer wavelength side and one peak in the shorter wavelength side in one-periods. The waveforms seem to be general in radial vibrations of wheels. The spectra of Bragg wavelength changes show the two major peak frequencies. One is the rotational first-order frequency and the other is the rotational second-order frequency. The powers of the two frequencies are almost same. The spectra also show that the FBG sensor detected wide frequency-range vibrations from 1 Hz to 1.3 kHz. These results reveal that FBG sensors are effective to measure vibrations of wheels. Moreover, the testing and evaluating techniques in the test using an FBG sensor facilitate to measure vibrations of rotating wheels.

Keywords

• fbg sensor
• strain measurement
• vibraion measurement
• road wheel
• wheel bench test
• rotating object