In this paper, a parametric study of the pilot-vehicle closed-loop system is presented. The study is based on the heading and lateral stability region using a lead-lag compensator to represent the human driver. A two degrees of freedom model is used to describe the yaw and lateral velocity of the vehicle. The effects of the vehicle moment of inertia, C.G location and cornering stiffnesses on the maximum crossover frequencies of the system are investigated. The relationship between these parameters and the maximum crossover frequency is obtained using a multi-nonlinear regression analysis from which the optimum problem is formulated and solved using Lagrange multipliers. The optimum values are used to form hypothetical vehicle models which are compared with the typical vehicles. The obtained results suggest some fundamental changes in the tire cornering stiffnesses, C.G location and mass moment of inertia. Simulation results in the frequency and time domains illustrate the effectiveness and capabilities of the proposed vehicles over the typical ones. (A)
Abstract