Analytical description and optimization of the dynamic behaviour of passively suspended road vehicles

A simple two-degree-of-freedom linear model is used to derive a number of analytical formulae describing the dynamic behaviour of passively suspended vehicles running on randomly profiled roads. Two different power spectral densities are considered for modelling the road irregularity. The derived analytical formulae can be used either during preliminary design or for other special purposes, especially when approximated results are acceptable. An optimization method, based on Multi-Objective Programming and Monotonicity analysis, is introduced and applied for the symbolic derivation of analytical formulae featuring the best compromise among conflicting performance indices pertaining to the vehicle suspension system, i.e., discomfort, road holding and working space. The optimal settings of the relevant vehicle suspension parameters (i.e., tyre radial stiffness, spring stiffness and damping) are derived either symbolically and/or numerically. (C) 2001 Academic Press.