Kinematic and Curvature Analysis of the McPherson Eight-Bar Suspension System

Abstract This paper deals with the kinematic and curvature analysis of the McPherson eight-bar suspension system that is developed by referring to a suitable planar car model, where both front wheels are supposed as rotating about their fixed revolute joints. In particular, the position analysis of the eight-bar mechanism, with an internal six-bar loop, is formulated to analyze the chassis roll motion by devoting particular attention to the roll center and its fixed and moving centrodes. Consequently, the curvature analysis is also carried out by using the Euler-Savary equation and the inflection circle, in order to determine the center of curvature of the mass center trajectory for the chassis roll motion. Finally, the proposed formulation has been implemented in a Matlab program and several examples allowed its validation in different mechanism configurations.