Vehicle Road Profile Estimation using Measured Acceleration Data

In automotive engineering, one of the most significant parameters that affects a vehicle’s dynamics is the road profile a vehicle travels over. The road profile refers to the longitudinal shape of the road surface. In other words, it refers to the modelling of the various vertical deviations in a road’s surface such as bumps and holes. When modelling a vehicle and analyzing its dynamical behavior, the road profile is considered as a primary source of excitation that has important implications in ride comfort and vehicle stability. To represent the road profile mathematically, various methods are employed with various degrees of accuracy. Some of these methods include assuming the road profile is a sinusoidal function or white noise. This project will focus on searching for an accurate method to estimate the road profile by measuring the vertical acceleration of a vehicle. An experimental setup containing an IEPE accelerometer and appropriate data acquisition system will be used to measure a vehicle’s vertical acceleration and then a four degree of freedom vehicle model will be used to obtain the road profile mathematically. After that, this project will use the estimated road profile to focus on two main areas: estimating the life of a vehicle suspension system and estimating the amount of energy loss in the vehicle’s suspension. A vehicle’s suspension system is primarily responsible for isolating the vehicle from the vibrations caused by the varying shape of the road profile. However, in doing so, large amounts of energy are lost and the suspension system’s durability can be greatly affected. Thus, estimating the road profile accurately can greatly aid in calculating the accurate life of a suspension system and how to increase it, along with accurately estimating how much of the lost energy can actually be recovered.