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Heavy trucks are produced with a great variety of vehicle configurations, operate over a wide range of gross vehicle weight and sometimes function in extreme duty environments. Frontal crashes of heavy trucks can pose a threat to truck occupants when the vehicle strikes another large object such as bridge works, large natural features or another heavy-duty vehicle. Investigations of heavy truck frontal crashes indicate that the factors listed above all affect the outcome for the driver and the resulting damage to the truck Recently, a new chassis was introduced for on-highway heavy truck models that feature frontal airbag occupant protection. This introduction presented an opportunity to incorporate the knowledge gained from crash investigation into the process for developing the crash sensor's parameter settings.

This paper describes some basic aspects of designing a medium and heavy-duty truck cab shell. Since the North American market has been dominated for the last several years by conventional, cab-behind-engine trucks and tractors, only cab shells for this type of vehicle will be discussed. The challenges in designing a medium and heavy-duty truck cab are different from those for a car or light truck body. This paper will highlight some of the differences and describe in detail part of the unique design criteria of truck cabs. Unless otherwise stated, the further use of the word truck will only refer to medium and heavy-duty vehicles.

Sound Ergonomics is an important attribute and differentiator among trucks, because professional truck drivers spend many hours of their work time on the road driving. Ergonomics affects areas of driver safety, comfort, accommodation and performance. The purpose of this paper is to showcase the ergonomic principles, tools and process that were applied throughout the development cycle of Freightliner's new Medium Duty Truck: Business Class M2. An important centerpiece of the ergonomic process at Freightliner is RAMSIS, a 3-D Digital Human Modeling software. It allows effective evaluation of ergonomic issues in the CAD environment early on in the development cycle, thus reducing the risk of expensive re-designs at later stages in the vehicle development process. Several examples with RAMSIS will highlight the benefits of applying 3-D human modeling to the design process.

A liquid fuelled, fuel cell auxiliary power unit (APU) can provide efficient, quiet and low pollution power for a variety of applications including commercial and military vehicles. Truck idling regulation, customer comfort or military “stealth” operation by using electrical power, require a device disconnected from the main diesel engine. The power can be utilized for air conditioning as well as other auxiliary systems found on board commercial trucks for driver comfort. In a military vehicle, this regulated power could be supplied to telecommunication and other computer equipment required for military operations. A system designed to be an add-on or retrofit solution using alternative fuel can have the potential to meet these requirements on the hundreds of thousands of existing vehicles currently in service or as optional equipment on a newly procured vehicle.

Understanding external vehicle aerodynamics is an integral step in reducing overall vehicle fuel consumption. This is particularly true for long-haul commercial vehicles where an incremental decrease in drag can translate into significant fuel savings based on the number of miles traveled over the course of a truck's working life. The ability to critically analyze the air motion adjacent to commercial vehicles is a step toward understanding the overall affects of external aerodynamics on the entire vehicle. To achieve this understanding, the aerodynamics problem must be divided into manageable tasks that can each yield qualitative and quantitative results. A two-dimensional (2D) External Aerodynamics Tool (EAT) has been developed that enables computational fluid dynamics (CFD) simulations of commercial vehicles to be performed quickly and easily.

Recently public agencies have been promulgating idling bans in an effort to mitigate the environmental effects of heavy-duty truck idling. In order to make rational choices, regulators, manufacturers, and consumers will need to compare idling reduction strategies, such as truck stop electrification and auxiliary power units. Truck driver behaviors, such as idling time, idling location, and accessory use will significantly influence the cost-effectiveness of the various technology options. Truck driver attitudes toward idling and idling alternatives will influence adoption of the technologies. A pilot survey of 233 line-haul truck drivers was administered in Northern California as the first step in assessing truck driver behaviors and attitudes related to idling. Initial findings reveal that line-haul truck drivers idle primarily to power climate control.

Late in 1999, Freightliner LLC commissioned a group to design and assemble a Sterling heavy truck for the 2000 Pike's Peak International Hillclimb. Many design and engineering innovations were necessary in order to optimize the total package for vehicle performance. Addressed will be the design and analysis used in optimizing the chassis/roll cage assembly for maximum torsional stiffness. Overall vehicle packaging for obtaining the vehicle weight and center-of-gravity location will be presented. Design details will be discussed for the truck-based front and rear suspensions, the special tire characteristics, the high performance powertrain, the rear axles, the cooling module and the rack and pinion steering.

This paper discusses one method for reducing heavy-duty truck rollover accidents, the Freightliner/MeritorWABCO Roll Advisor and Control (RA&C) System. It describes the operation of this system and the unique way in which RA&C trains drivers to avoid high-risk rollover and braking conditions. In addition, the rationale for this approach is discussed in terms of Behavioral Based Safety (BBS), and the means employed to communicate with drivers is described. A technical description of the RA&C system is presented including a discussion of the challenges of designing and developing this product to be a cost-effective system readily implemented in today's commercial vehicles. Resolution of these challenges leads to the choice of the ABS platform to house and operate the necessary electronics and software along with the Freightliner Driver Message Center for displaying driver information.

Sterling, a new brand name in the trucking industry, wanted to develop a competitive medium duty product. The Sterling cab is versatile and can be adapted to meet target market needs. However, the Sterling chassis is heavy and expensive for medium and light-heavy applications. Freightliner chassis components provide a more versatile platform. The Sterling cab and Freightliner chassis provided the starting point for development of a new product called ACTERRA. Sterling's need for this product required an aggressive development plan. Although timing was critical, other major project targets were desired, including low cab height, good visibility, maneuverability, low cost, product flexibility, and attractive appearance with strong ties to a Sterling family identity. The result is an attractive and competitive package delivered to the market in minimum time. This paper summarizes the product content and project approach taken to launch ACTERRA.