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This paper presents an on-board instrumentation to evaluate articulated vehicle maneuvers, using a system that combines a set of sensors and a GPS receiver with custom-made evaluation software. This system allows evaluating vehicle maneuverability and the performance of the truck's driver in real time. Also the performance measures and test maneuvers are briefly described.

One of the main concerns in road conservation and maintenance activities is the interaction between tire and road through the contact patch. The internal air pressure and the weight supported by the tire are factors that affect the force and pressure transmitted to road surface by the vehicle. An experimental study related with load distribution and pressure in the tire's contact patch is presented in this paper. For testing, a lab prototype was used to determine the static load distribution along and transversally to the tire's contact patch. Two types of tires, both for light trucks, were used: one single radial and the other bias-ply, this last type in dual configuration. Several combinations of vertically supported load and air pressure were applied to testing tires. Results showed that contact pressure is uneven in the contact patch and lower than air pressure for the radial tire, but in some cases higher for the bias-ply tires in dual configuration.

Heavy vehicles commonly use dual tires on their load and traction axles. As the only vehicle component involved in force transmission to the road, the tire is an important element in the road damage process. In this context, two factors involved are the tire's supported load and inflation pressure. Traditional practical assumptions are that each of the tires in dual arrangement supports the same load, and that the contact patch pressure is very similar to the tire's inflation pressure. To provide data about the load distribution and contact pressure in the tire's contact patch, a lab experimental study was carried out. For that, a lab device was used to determine the static load and pressure in the contact patch, using three different sets of heavy duty radial tires subjected to several combinations of supported load and inflation pressure.

Trucks with semi-trailers are widely used for transportation of goods due their low operation cost, but inherent to these vehicles are some problems such as a poor maneuverability. To minimize the effects of this disadvantage, among other solutions, the incorporation of steerable axles in the semi-trailers has been proposed. This paper presents a steering equation, and a fuzzy-logic controller for a semi-trailer automatic forced-steering system to minimize the off-tracking and the total swept path width, resulting in an improvement of vehicle's maneuverability at low speeds. To accomplish this, the suggested control algorithm considers the articulation angle, and parameters such as vehicle speed and direction. The system was tested on an instrumented experimental semi-trailer during various predetermined test maneuvers.

The tractor-trailer combination is one of the articulated vehicular configurations for road cargo transportation most widely used. Due to the length of these articulated vehicles and the coupling geometrical characteristics, they undergo poor maneuverability. In order to obtain a better understanding of the maneuverability, this paper deals with an experimental one-axle semi-trailer coupled to a light duty pick up truck being used to perform some low speed maneuvers. These test maneuvers include stationary and transient turns, as well as slalom type ones, performed while the semi-trailer axle is set directionally straight or steerable. During each maneuver condition, parameters as planar articulation angle, tractor and trailer yaw rates, and the correspondent steering angles were measured.

In this paper, the importance of determining the lateral acceleration to characterize terrestrial vehicle behavior and its performance is addressed. Also, the technical difficulties to measure such acceleration and its dependency with vehicle roll angle are described. In the analysis of the motion of the vehicle's center of gravity (CG) and regarding to transversal acceleration components, the acceleration of gravity is taken into account to determine the roll angle, the lateral acceleration and the behavior of vertical acceleration component. As a result, and based upon the principles of operation of accelerometers, a scheme for a simple instrumentation to estimate the roll angle and lateral acceleration in an experimental assessment, is suggested as well.

The effect of wheelbase variation on the rollover threshold for a three axles' unit heavy-duty vehicle, is presented in this work. For this, a vehicle dynamic behavior simulation model to analyze lateral stability is used. Also, the concept of load distribution on rear axles and the relationship with geometric definition of wheelbase is incorporated, and so, the effect on handling characteristics is analyzed. Besides, results of the combined effect considering stiffness suspension in front and rear axles on resulting handling is included, according wheelbase variation. Results suggest a wheelbase value in which the vehicle highest rollover threshold is obtained.

The dynamic behavior of heavy vehicles moving on roads depends on load magnitude and its distribution, and a special concern may be directed to tankers. Liquid cargo at partial filled levels exhibits sloshing during vehicle longitudinal displacement, generating some forces which might alter vehicle's directional response and traction control. To attenuate the sloshing dynamic effect, transversal plates (baffles) are placed inside the container but increasing the structural container mass, arising vehicle's mass center and decreasing vehicle's useful load capacity. An experimental study on the effects of fill level and number of baffles on the sloshing attenuation is presented. For doing so, an instrumented scaled experimental tank of elliptical transversal section is used with water as liquid cargo, and longitudinal sloshing force is measured.