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The height of a vehicle's center-of-gravity (CG) is one factor that influences its handling characteristics. A number of height methods are used to measure CG within the automotive industry. This research determined which method has the greatest potential to produce accurate CG height measurements, given anticipated measurement tolerances. Several techniques for measuring vehicle CG height were analyzed mathematically. The contributions of various parameters to total error were determined and the total error inherent in each method was then compared.

Tire marks left by the vehicle prior to impact, rollover, or other event, are important forensic evidence reconstruction of motor vehicle accidents. Often these tire marks have some curvature that is measured and used to calculate the speed of vehicles prior to the event. This calculation is based on the coefficient of friction of the tire/road interface and the radius of curvature of the vehicle center of gravity (c.g.) path. There is controversy about the validity of this approach. To explore this theory, a test vehicle was driven through a series of maneuvers that produced yaw marks for direct comparison of actual vehicle velocity to the velocity calculated by the critical speed formula. Test results show the critical speed formula is inaccurate for most circumstances and does not correctly describe vehicle limit performance behavior.

A vehicle may be loaded in varying configurations that affect its mass properties during normal use. These properties include total mass, center-of-gravity (Cg) location, and moments of inertia. The ranges of these parameters, which are determined by the varied load configurations, define the vehicle's mass property envelopes. These envelopes are useful for evaluating the effect of any load configuration relative to vehicle performance/design specifications. Mass property envelopes provide a clear visual representation of a range of key parameters that significantly affect motor vehicle control. Examples are provided in this paper that illustrate the usefulness of the vehicle mass property envelopes.

Using analysis of a mini-van test vehicle’s static load conditions as a guide, four different vehicle loading situation were constructed. The loading situations represent the corners of the vehicle’s center of gravity position envelope. For the testing described in this paper a single vehicle under conditions of varied load was subjected to a series of test maneuvers designed to elicit objective measure and comparison of vehicle steady-state and transient response. The purpose of this paper is to describe the test method and present the results of handling testing and limit stability testing of a 1991 Ford Aerostar mini-van/extended van under four different loading conditions. Differences observed in the plotted results of vehicle steady state response for different load condition are detectable, but small. The test results demonstrate differences in vehicle transient response for different loading configuration.