Search Results

Regulated emissions, CO2-values, comfort, good driveability, high reliability and costs, this is the main frame for all future powertrain developments. In this frame, the diesel powertrain, not only for passenger cars, but also for commercial vehicle applications, faces some challenges in order to fulfil the future European and current US emission legislations while keeping the fuel consumption benefit, good driveability and an acceptable cost frame. One of these challenges is the varying fuel qualities of diesel fuel in different countries including different cetane number, volatility, sulphur content and different molecular composition. In addition to that in the future, more and more alternative fuels with various fuel qualities and properties will be launched into the market for economical and environmental reasons. At present, the control algorithms of the injection system applied in most diesel engines is open loop control.

During the past years, there has been an increasing tendency to seriously question and break up old and ingrained structures in combustion engine testing. The reason for this is the continuously increasing number of engine and vehicle variants and a variety of applications resulting from it, which significantly push up development costs and times when carrying out the classical testing patterns. The following article by FEV Motorentechnik GmbH introduces a comprehensive test methodology for purposeful endurance testing of modern drive units (in particular from the fields of passenger cars and commercial vehicles). The procedure and the testing philosophy are explained in detail, illustrated by a concrete development example.

A study to determine whether performance-based brake testing technologies can improve the safety of our highways and roadways through more effective or efficient inspections of brakes of on-the-road commercial vehicles is being sponsored by FHWA/DOT-OMC. A key objective of the study is to determine how the results from performance-based “inspections” compare with results obtained through traditional visual methods, such as those recommended by the Commercial Vehicle Safety Alliance (CVSA). Data from joint inspections (i.e., CVSA and performance-based inspections on the same vehicle), obtained over approximately a one year period, have been analyzed. Description of three of the performance-based technologies and preliminary results from approximately 1,400 joint inspections are covered in this paper.

There is recent interest in examining whether performance-based brake tests are advantageous compared to presently used visual inspections for safety checks of on-the-road commercial vehicles. In this first of a series of two papers, the basic features of visual inspections and performance-based brake tests are presented and discussed. It is shown that the visual inspection method is inherently “predictive” in nature and therefore conservative. A performance-based brake test is objective but not predictive. The performance based test may reveal safety-related defects only for the specific vehicle load configuration and operating condition. The presentation is concluded with a discussion of what may be required for future enforceable use of performance-based brake testing devices for “on the road” inspections of commercial vehicles. In the short term, use of performance based testing will depend on correlation of test results with presently enforceable visual methods or standards.

Dry dust testing of vehicles on unpaved dust roads plays a crucial role in the development process of automotive manufacturers. One of the central aspects of the test procedure is ensuring the functionality of locking systems in the case of dust ingress and keeping the dust below a certain concentration level inside the vehicle. Another aspect is the customer comfort because of dust deposited on the surface of the car body. This also poses a safety risk to customers when the dust settles on safety-critical parts such as windshields and obstructs the driver’s view. Dust deposition on sensors is also safety critical and is becoming more important because of the increasing amount of sensors for autonomous driving. Nowadays, dust tests are conducted experimentally at dust proving grounds. To gain early insights and avoid costly physical testing, numerical simulations are considered a promising approach. Simulations of vehicle contamination by dry dust have been studied in the past.

Dust testing of vehicles on unpaved roads is crucial in the development process for automotive manufacturers. These tests aim to ensure the functionality of locking systems in dusty conditions, minimize dust concentration inside the vehicle, and enhance customer comfort by preventing dust accumulation on the car body. Additionally, deposition on safety-critical parts, such as windshields and sensors, can pose threats to driver vision and autonomous driving capabilities. Currently, dust tests are primarily conducted experimentally at proving grounds. In order to gain early insights and reduce the need for costly physical tests, numerical simulations are becoming a promising alternative. Although simulations of vehicle contamination by dry dust have been studied in the past, they have often lacked detailed models for tire dust resuspension. In addition, few publications address the specifics of dust deposition on vehicles, especially in areas such as door gaps and locks.