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After the anti-skid brake system (ABS) introduction, mandatory for all vehicles in the Brazilian market, manufacturers have given increasing attention to optimized systems which meet legal and safety requirements. For commercial vehicles, an alternative for the ABS, which presents feasibility, is the configuration 4S/3M (4 wheel-speed sensors and 3 modulator valves) in substitution to the configuration 4S/4M. In other words, application of just one modulator valve to control the brakes of the same axle, front or rear, instead of independent control per each brake of the vehicle. The aim of this paper is to present a performance comparison between a brake system fitted with ABS configuration 4S/3M and an ABS configuration 4S/4M. To this end, both configurations were tested on the same vehicle application in accordance with the Brazilian legislation, CONTRAN 519/15.

With the constant evolution of vehicle systems becomes increasingly challenging the Components project. The demand for mass and cost optimization in a challenging project schedule scenario generates a great challenge to the engineering teams, who look for design and development methods more assertive. In order to reduce the risk of failure, testing time and design cost, simulation tools are being increasingly used. A major challenge in the component project for trucks and buses is the knowledge of the real loads that the components are subjected. In the case of propeller shaft bearings several factors should influence the magnitude of the efforts. The biggest influent factors that has been studied and discussed widely for many years are the torque and joints angles.

The higher is the volume of automated transmissions for high load capacity commercial vehicles in the market, the higher is the necessity to develop auxiliary systems capable to reduce the wear of the clutch disc during start-ability performance in slopped plans. The Hill Start Assist System, HSA, is compounded by a set of components in the brake system, disposed in such a way that provides to the driver the possibility of starting to run with comfort and safety by the actuation of the service brakes, without overheating the clutch system and simultaneously avoiding the undesirable effect of composition roll-back. For this, it is only necessary that the vehicle be equipped, besides automated transmission, Anti-lock Braking System, ABS, and an active traction control in, at least, one of the drive axles.

In engineering development, simulation methods are frequently used to perform thermal and mechanical stress components analysis. In brake systems, where the components are exposed to mechanical and thermal loads, the numerical analysis is very helpful. Once a numerical model for brake assembly is available, it will be possible to understand the effects of successive brake applications on the temperature distribution in drum brake's friction materials. This is a fundamental aspect to determine, for instance, the thermal stress distribution which is related to the warming and cooling of the brakes. In this work, an analytical solution to calculate stabilized temperature was used to establish a heat flux through a pneumatic S cam drum brake's friction material applied to a numerical model in a finite element analysis.

Simulations tools like AVL Cruise and Vehicle Dynamics where used to carry on a comparative study between two trucks equipped with automated manual transmissions in two configurations: the original with 12 gears, and a proposal with 16 gears. The original configuration is world-wide used and in this way, the present study was fundamental to decide whether choosing the new proposal would bring the Brazilian option any advantages. In order to evaluate the whole vehicle behavior fuel consumption evaluation and vehicle performance were analyzed. From the present study, it was showed that the 16 gears transmission was the best alternative for the Brazilian application.

Evaluation of vehicle performance is one of the most important phases of the new vehicle development. Start Ability and Top Speed are factors that are noticed by users, therefore are very important to the final product. Vehicle performance evaluation has been largely benefited from the use of simulation tools. In fact, MAN Latin America (ML) employs simulation programs to evaluate the performance of its vehicles (trucks and buses) achieving good results. However, those programs are normally “closed codes” which makes difficult the physical comprehension of results. Altogether, this article presents Vehicle Dynamics, a macro developed by ML engineering team. The aim of this macro is the automatic calculation of Start Ability, Grade Ability, Top Speed, among other performance parameters.