The Influence of Vehicle Tyres Pressure on the Suspension System Response by Applying the Time-Frequency Approach

Maintaining correct inflation pressure in tires
helps to keep vehicle handling, passenger comfort and
braking at its best, as well as improving fuel efficiency and
tire life. Therefore it is very important that the tires are
correctly inflated. To address this problem, in the present
study experimental investigations have been carried out to
identify the effect of under-inflated tires on suspension
system performance by measuring vertical acceleration
(vibration) of the suspension system. The experimental work
has been conducted by driving a car on the road with range
of inflation pressure at four conditions (e.g. at standard
pressure (2.3bar) and at 1.5bar of passenger wheel, driver
wheel and front wheels). During the experiment the signals
of tire pressure, the suspension vibration and the car speed
were measured.
To analyze the signals, the Short-Time Fourier Transform
(STFT) method was used to detect the effects of tire inflation
on the performance of suspension. The STFT technique has
provided time-frequency information and the frequency
components of the signal with relative maximum energy
transmitted to the car body.
The results show that, when the tires were under-inflated by
approximately 35 percent, it was significantly increased the
vibration of the car body by up to 30 percent. The analysis
has also shown that STFT analysis is more accurate than the
spectrum analysis for distinguishing of the tire fault. These
effective measurements potentially will use to develop an online
condition monitoring system in future.