Effect of Non-linear Suspension on the Recognition of the Road Disturbance

The road excitation is one of the major forces which act on the vehicle and affect the passenger’s comfort so it constitutes a crucial field of interest when suspension systems are designed. Hence, identifying this type of excitation remains very benefiting since it contributes to study the dynamic behavior of the vehicle and to apply a controller law in order to ensure the passenger comfort. Direct recognition techniques (longitudinal profile analyser or laser sensors…) of the road profile are costly, thus, it is necessary to find other methods such as numeric ones to recover the road disturbance. In this paper, the inverse problem theory is employed to pick out the road profile disturbance applied to vehicle. This proposed technique, known as the Independent Component Analysis (ICA), can recreate initial excitation sources by using physically measurable signals named observed signals of the system under study. These signals are obtained numerically in this study by using the Newmark approach. Starting from these dynamic responses, the ICA algorithm is applied to a non-linear vehicle model to identify the road excitations. The performance of this technique is studied using some criteria which are the relative error and the MAC number. The obtained results show a good relevance between the original signals and the estimated ones.