How well a single-track linear model captures the lateral dynamics of long combination vehicles

The effect of centre-of-gravity heights on the high-speed performance measures of long combination vehicles including truck with double centre-axle trailers, Nordic, and A-double combination vehicles is investigated. The high fidelity three-dimensional models, used in this research, are validated against physical test data. These models are often effcient to the reality in terms of the actual dynamic behaviours of the vehicle systems. On the other hand, the simple yaw-plane single-track models with linear tires are very easy to construct and require less number of vehicle parameters. In this paper, it is investigated how accurate the estimations of performance measures are at high forward speeds by such single-track linear models which are incapable to differentiate between the different heights of payloads. The high-speed performance-based standard or PBS measures considered are rearward amplifications of both lateral acceleration and yaw velocity; lateral load transfer; yaw damping; and high-speed transient offtracking.