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The fuel consumption is an important factor in the vehicle development due the fact that it has a direct effect on its trade aims. Besides that, it is known that the petrol is a scarce fuel. In this paper it is presented a procedure of fuel consumption calculation for a vehicle traveling in driving schedule. In such calculation it has been taken into account the operational conditions (load, pavement, climbing road, among others) and the building characteristics (map engine, transmission, frontal area, tire, among others) of road vehicles. There has also been an application of the theoretical model developed in a sample Mercedes-Benz do Brasil vehicle which has been compared with the values of experimental tests.

As the automotive industries join the Global environment, the component suppliers need to adapt to this reality. This brings new challenges to be accommodated. Conflicting objectives, as seen from a traditional point of view, must be harmonized: Centralization of core development and simultaneous presence in the customer's sites are difficult to manage. A network of technical centers has to be wisely distributed around the world in order to allow for optimum coverage with all potential customers. Also the new tendency of modularity imposes leaving from a pure component design to modules and subsystems integration. This paper gives, based on a real case experience, some insights on best ways to meet these challenges and focus mainly in the task of designing for globally managed car programs. The most common scenario nowadays for a new car program development is to have a central platform design which allows for local market exception needs, These needs will vary from region to region.

This article has as objective the demonstration of a methodology to create component test rigs using numerical simulation techniques (FEM - Finite Element Modelling) as an aiding tool. It also emphasises the interaction between modern design procedures and experimental testing, regarding their consequences to product development. The case study was the development of a prototype chassis components durability test rig. The target was to reproduce a failure occurring at a crossbeam subframe on the assembly with the leaf spring mounting in order to test possible proposed solutions. An initial rig concept was created using experimental data. This conception failed to reproduce the crack at the point where it occurred in the prototype. A new rig was virtually designed and simulated. As the simulation showed proper results, it encouraged the construction of this new rig, which reproduced the failure as expected.

It is well known that the temperature and its variation have a great effect on the observed deceleration and on the braking system efficiency. The temperature and its variation between brake disk and pads or braking lining and drums can change significantly the braking factor which in other hand affect the performance of the system in a emergency braking process. In this work the braking system and the braking dynamics of a standard road vehicle (a bus ) were analytically simulated in a computer programme. The computer programme can simulate the vehicle in a emergency braking taking in account the temperature variation between braking lining and drums in order to predict the deceleration variation due to the temperature in a standard road test. It is also possible to predict the braking process efficiency for various operational conditions of the vehicle.

This article describes the advantages of in-vehicle control networking over traditional distributed control systems with a central processor. A suitable standard protocol. CAN this is a communication bus for message transaction in small-scale control network system, is presented and its current and future uses are discussed.

This paper presents a weld process improvement, where it was obtained quality and productivity gains, through full productive process control. Using Design of experiments methodology (D.O.E), a pilot project was developed that consist of porous minimization at the welded joints of McPherson's shock absorbers struts, that could result in efficiency loss in the shock absorber struts with products image deterioration. This work is part of the D.O.E. methodology application at COFAP, that has the target to develop this ability looking for to attend APQP Handbook - Advanced Product Quality Planning and Control Plan of QS-9000. Together with an consultant company a work group was created in order to disseminate the D.O.E. methodology in the COFAP - Suspension System Business Unity technical personnel. The job phases are as follows: 1. Problem definition; 2. Planning; 3. Logistic and structuring; 4. DOE practical implementation; 5. Results Collection; 6. Results grouping; 7. Analyzing; 8.

In business today, the threat of competition has become devastating to many established organizations. The balance and optimization of cost, schedule, and quality in part defines the struggle of many competitive organizations. Entire organizations are being aligned and focused on cost, growth, customer service and profitability even if they are the market leader. Maintaining the status quo can be fatal. Of course Just-in-Time (JIT) Manufacturing is not all you need to remain competitive, but without its innovative techniques one will be at a strong disadvantage. When one thinks about what drives any reaction, informational input comes to mind. Information in the form of the human five senses stimulates all reactions by humans. The same can be said for manufacturing. Information causes a manufacturing reaction. If this information is used properly, and supported with other JIT techniques, significant cost can be reduced.

This paper shows the performance, the braking distribution and the compatibility of heavy vehicles during braking process. including some ECE-R13 [1] requirements to brake systems of these vehicles. Also, it will be shown satisfactory results reached on comparisons between theoretical and experimental values of braking performance of the example vehicle. For the achievement of this work, a mathematical model and a computer program developed for the commercial vehicles braking process study were used, that permits the obtainment of performance and of braking and vertical forces distribution charts to the example tractor-semi-trailer during braking process.

Rear underride crashes are responsible for thousands of deaths every year in Brazil. To support the fight against this calamity, it was design and tested an articulated guard able to avoid car underride. Because of its articulation capability, this guard can be placed as low as necessary without impairing the truck maneuverability. Crash tests were carried out with the new guard and with another one constructed according to Brazilian standards. The articulated guard was able to avoid underride of a vehicle GM Corsa colliding at 50 km/h in offset of 50%. The other guard could not avoid underride under the same test conditions.

In late 1996, Daimler-Benz together with WABCO and Scania together with Bosch presented the first electronically controlled brake systems (EBS) in their towing vehicles. Since then roughly 2000 ACTROS per month have been produced with EBS. Other vehicle manufacturers will introduce EBS in the near future [5]. The technical advantages of EBS combined with the increased application of disc brakes, are: improved safety through shortened stopping distance better vehicle stability and brake comfort optimized brake monitoring and higher profitability However, with this first step the technical possibilities are limited to towing vehicles combined with conventionally braked trailers. The overall braking performance of the combination unit can be further improved when the trailers are equipped with an electronically controlled brake system.

This paper presents the Vehicle Dynamics Control (VDC) for commercial vehicles developed by BOSCH. The underlying physical concept is discussed in the second section after a short introduction. The third section shows the computer simulation used in the development process. Section four describes the controller structure of the VDC system. In Section five the use and effectiveness of VDC for commercial vehicles is shown in different critical driving situations. This is done by using measured data collected during testing (lane change, circular track) and it demonstrates that the safety improvements achieved for passenger cars are also possible for commercial vehicles.

The European automotive EMC directive, 95/54/EC, provides the EMC approval regime for motor vehicles of 4 wheels or more and all equipment intended for fitment to them. The EMC Chapter of the European multi-directive for 2/3 wheeled vehicles, 97/24/EC, provides the approval regime for these vehicles and their equipment. Regulation 10 of the United Nations Economic Commission for Europe (ECE) is being updated to provide similar EMC requirements. ISO draft standards are available for forestry and agricultural tractors, and for earth-moving machinery. This paper explains the relationship of these different approvals to the general EMC directive, 89/336/EEC, and offers interpretations for vehicles and their components as well as the implications for the various types of aftermarket components.

Transmission shift lever jumpout is a truck system dynamics problem that is caused by engine/transmission pitching in response to rough road input. Severe rotational motion imposes inertial forces on the shift lever system, potentially causing the shift rail to move to neutral. Dynamic testing and analysis has led to suggestions for system design improvement including lever geometry optimization and engine mount stiffness and damping improvement. A counterweight addition to the lever system will also stabilize the dynamics.

Tests of class 2,3,and 5 straight trucks were made to determine the affect of aftermarket aerodynamic aids on fuel economy and handling. It was determined that the potential exists for significant improvement in the fuel efficiency of these classes of trucks.

Allison Transmission has developed a family of two new automatic transmission products, the 1000 Series and the 2000 Series, for the light and medium duty commercial markets. This technical paper will introduce these products by reviewing the early development efforts which helped define the transmission attributes that they should bring to market. This included the analysis of Allison's product portfolio and industry rating requirement trends, and the extensive market research which identified the key product attributes and led to the concept selection. There is also a review of the 1000 Series and 2000 Series product features as well as a discussion on the development of their respective vocational ratings. Future papers will provide greater detail on the various technical aspects of this new product family's design.

This paper is a discussion of the thermodynamic properties of typical heavy duty mechanical truck transmissions, including maximum operating oil temperature requirements and rationale, effect of synthetic oil, sources of heat generation, prediction of total heat generation, and cooling systems.

Based on analysis problems of vehicle with present automatic transmission, an Intelligent Shift Strategy(ITSS) is proposed for the first time. Three kinds of information, which are the driver intention, the vehicle dynamic characteristics and the outside environment, are included in it, and the humachine technology is applied to decide shift strategy.

The active safety of tractor / trailer-combinations plays an important role in regard to traffic safety in general. For improving the active safety of tractor / trailer-combinations, it is necessary to investigate the interactions between the towing vehicle and the trailer during braking maneuvers. This paper describes the ECE-regulations for the braking force distributions of tractor/full trailer- and tractor / semitrailer-combinations. The influence of different layouts of the braking systems within these regulations on the coupling forces between tractor and trailer and the driving performance of the units during braking is investigated. The dynamical behaviour of a tractor/full-trailer-combination and a tractor / semitrailer-combination are both discussed with the aid of simulations of the ISO-standard testing procedures “Braking in a turn” and “Braking straight ahead”.

Difficulty of the Automatic Transmission(AT) is to properly control its clutch while the vehicle starts. An intelligent hierarchical controller is proposed in this paper. The upper of it is an intelligent PID controller based on a driver's experience and an expert's knowledge. It gives real time signals to the lower controller and coordinates the control between engine and clutch. The lower Variable Structure Fuzzy Controller (VSFC) executes the upper controller's direction signal.

The cruise control as one of promising vehicle active control has been receiving a considerable attention in recent years, so the related problems are discussed in this paper. Mathematical model of the engine under the steady state and general dynamics equation of the Continuously Variable Transmission(CVT) are given, the regulating principle of the operating state of the engine is analyzed, and the conjugate gradient method employed to solve the optimal control problem of the vehicle in the cruise control is described, so the operating state of the engine could be controlled. At end of paper, some results are provided to verify the approach based on the vehicular powertrain with a hydromechanical CVT.