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The paper looks for the degree of linear correlation of some acoustic parameters when their results are compared taking into consideration the internal noise of a set of passengers cars and another set of commercial vehicles. The acoustic parameters dealing with the overall noise (Loudness, dB(A) and dB(B)) and those related to the high frequency portion of the spectrum (Articulation Index and Sharpness) are chosen. The sound pressure levels in the passenger compartment are measured according to ISO 5128. The parameters are calculated in some specific velocities. A least square fit to a straight line to each pair of the acoustic parameters is applied. The results are discussed taking into consideration the degree of correlation trying to investigate how dependent or independent the parameters are. In addition it is possible to see the fluctuation range of these parameters concerning each set of vehicles.

This paper intends to show how Telematics has started in Brazil and describe its impact in the traditional way of making Business with commercial vehicles. We want to make a brief comment about the main enabling technologies for the Telematics improvement: Telecom infrastructure: the investments after the privatisation of the sector, as well, trends for new services (WAP, SMS, Tracking, etc); Internet infrastructure: the growing of internet accesses and its impact in the industrial economy; The impact of these new technologies in the trucking Business and how Brazil is prepared for. New investments that are coming; The impact of IT technologies in the Brazilian GIP (Gross Internal Product) and in the Transportation market.

The conventional and fixed maintenance intervals planned according to the vehicle application group (rough operating condition, short haul and long haul) are substituted by computed intervals, which correspond to the real components wear. The system carries out the prognosis of different services for periodic maintenance, indicating in the instrument cluster the dates when the services should be carried out as well as the remaining distance for carrying out each service. The system allows to join all different maintenance dates to only one date, improving the vehicle programming. The FSS totally integrated with CAN (Controller Area Network) line through a telematic system can centralize all maintenance prognoses in the transport company. Using this system, the user can reduce all documents and maintenance vehicle controls.

Competition in Automotive Market is driving the need for more time - and cost - effective testing methods. In the fatigue life analysis of new passenger and commercial vehicle designs, laboratory testing through servohydraulic equipment plays a very important role. In DaimlerChrysler do Brasil, the Durability Test Laboratory represents an important basis to assure high endurance reliability for all kinds of our commercial vehicle applications. In order to respond to the above mentioned testing tasks, this paper will focuse what we call our “New Policy of Durability Tests for Commercial Vehicles”, based on development of simple and low cost Road Simulators, fully dedicated and customized to testing of vehicle components and chassis. Experimental results as well as other data related to consumption of laboratory's: area, utilityes, pressurized hoses and test time, will be used in order to illustrate advantages and disadvantages of the new testing resource.

With the increasing necessity of reducing the development time of new products, and also the need to evaluate product reliability levels, a trend to rationalize field tests through test benches has been noted. These tests have proved more and more representative and carried out in much lower times and with lower costs. In the automotive industry this trend has generated considerable effort towards making these bench tests more representative of actual conditions towards the increase of their reliability. The quantity of simulated parameters is growing and it becomes necessary to collect more data from ground measurements signal (acceleration, temperature, pressure, flow, etc.) in experimental vehicles.

During the last years, DaimlerChrysler do Brasil (DCBR) has been moving ahead in order to research and to develop an Automatic Vehicular Location System (AVL System) due to the increase of the security through blocking and tracking devices, monitoring and mainly, logistic solutions that includes maintenance and fleet management. DaimlerChrysler do Brasil faced the necessity to prepare a test that could reflect a real situation, not only to try the system's features regardless communication and management of transmitted data, also however, to ensure the durability and reliability of the on-board vehicles equipment focusing on Brazilian Infrastructure. The objective of this paper is to describe the methodology, used tools and acquired results obtained by DCBR improvement test of his AVL System, throughout the “9o Rally Internacional dos Sertões - 2001”.

Due to the growing need of reducing development time of new products and also to evaluate their reliability, a growing trend towards reduction of field tests has been noted. Bench tests, in contrast, are being more widely used because of the reduced time to carry them out, at much lower costs. In the automotive industry this trend has led to great efforts to make these bench tests as truthful as possible in order to increase their reliability. The quantity of simulated parameters is growing and this, or course, requires the collection of an ever increasing quantity of data from signal measurements (acceleration, temperature, pressure, flow, etc.) in experimental vehicles.

The paper describes the acoustic development effected in one middle-class commercial vehicle with the purpose of achieving the external sound pressure levels dictated by new Brazilian legislation. The philosophy adopted as well as the mandatory modifications of the truck to fulfill the noise limits are showed together with the non-acoustic characteristics. Besides the acoustic treatment of some specific sources, it was introduced an acoustic barrier, usually called capsule or shield to reduce the noise emission of the engine-transmission assembly working by the mass law principle and sound absorption.

A mathematical simulation model was developed to calculate the cooling loads in a cab. The cooling loads calculations are described: Solar irradiation through glasses, conduction through the body walls and glasses, conduction through motor compartment, fresh air intake/infiltrations, people and equipments. Fields experiments were conducted to evaluate the conduction through walls and glasses and the total cooling load models. Precision less than 5% was gotten between experimental measurements and model results. In the summer situation, studies about the effects of the cab orientation, the time, the external paint and the tint of the glasses in changing the conduction and solar radiation cooling loads, were conducted. Cab orientation and the time can change this cooling loads by 225%. Variation by 30% was gotten from different paints and glasses.

When a new commercial vehicle project begins or some changes are necessary in the current products, the development of clutch pedals has a strong dependence with the powertrain characteristics which generally affects the clutch behavior and its actuation system. Although theoretical analyses are always taken into consideration, experimental procedures in bench tests and vehicles play an important role in the determination of new configurations for the clutch actuation system. Nowadays cost reduction, unification and quality gains must be considered in the project and development process. The above considerations mean that the work in bench tests regarding clutch actuation systems must be emphasized to simulate their behavior in the vehicle.

The objective of this paper is to present the update procedures and the future tendencies for the diagnosis projects in commercial vehicles, specially buses and trucks. The constant increase in the number of components and electronic systems in commercial vehicles demands that the subject “Diagnosis” be treated and previously defined, while the vehicle is in the project phase. The final goal of this thought is to provide to the vehicle the best possible acting of all the electronics systems placed in vehicle, and, as a consequence, the best running of the On-Board and Off-Board diagnosis systems which should assist the customer needs directly. The tendency is to project the vehicles of the same brand in the same conceptual line facilitating the assembly work in production line and the after sales support.

The objective of this paper is to present the update procedures and the future tendencies for the diagnosis projects in commercial vehicles, specially buses and trucks. The constant increase in the number of components and electronic systems in commercial vehicles demands that the subject “Diagnosis” be treated and previously defined, while the vehicle is in the project phase. The final goal of this thought is to provide to the vehicle the best possible acting of all the electronics systems placed in vehicle, and, as a consequence, the best running of the On-Board and Off-Board diagnosis systems which should assist the customer needs directly. The tendency is to project the vehicles of the same brand in the same conceptual line facilitating the assembly work in production line and the after sales support.

Because of the increasing need to reduce the time of development of new products, or even to evaluate the reliability of products, one has been noticing a trend to rationalize field tests through essays in ever more representative test benches, within a shorter period of time at a lower cost. In the automotive industry, the trend is to increase the reliability of tests in benches. The quantity of simulated parameters is increasing, what demands an ever increasing survey of data based on measurements of signals of deformation of leaves of spring leaf and courses of suspension in experimental vehicles.