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The development of larger more productive innovative heavy vehicle combinations for public road operations relies heavily on proving new vehicle concepts to both government and local authorities. In a number of cases simulation modelling has proved to be a useful tool in showing that proposed innovative heavy vehicle concepts are safer and more efficient alternative to conventional equipment. This paper provides examples of the use of AUTOSIM™ in developing custom yaw/roll and yaw/roll/pitch models for investigating the dynamic performance of combination vehicles. Models are described for large innovative road trains which incorporate B-doubles units. Consideration is given to the modeling of the trailing fidelity of these vehicles on non-planar surfaces and examples of model outputs for combination vehicles operating on various three-dimensional features are presented.

The variation in the decoupling effect of exhaust flexible couplings under a vertical preload caused by changes in the direction of the exhaust pipe routing was investigated. Both self-supporting and underbody flexible couplings were tested. The results indicate that, in general, a preload decreases the decoupling efficiency of both types of flexible couplings. In addition, the results indicate that the efficiency of the flexible coupling is effected by the following three conditions: the direction of preload with respect to gravity, the location of the preload relative to the coupling, and the stiffness of the various components of the flexible coupling.

Many design philosophies have been used to design engine mount systems. One is to place the stiffness roll axis coincidental to the torque axis (crankshaft), to produce pure roll under static torque. Another is to focus the mount system to align with the inertial roll axis and uncouple dynamic roll. Recent trends have been to abandon mount system focusing as a criterion, in favor of controlling the six natural frequencies of the powertrain on the mount system. This paper discusses a technique to focus the mounts to uncouple the dynamic matrix, as much as possible within design constraints, while also maintaining control of the powertrain rigid body natural frequencies. Using engine mount system focusing to uncouple the dynamic matrix reduced lateral shake in an experimental vehicle. This reduction in vehicle shake was substantiated by total vehicle system models, experimental measurement, and subjective evaluation.

Navistar International has developed and launched a new model for local and regional vocations, meeting customer expectations while reducing complexity. This was accomplished by listening to customers and delivering a product in a short period of time. This vocationally focused vehicle proves that features associated with a line haul premium conventional can be incorporated in a value driven local / regional day cab tractor. The swift time to market was brought about by a developing climate for performance that includes living values which support success.

Technologies and incremental costs for meeting the proposed 2004 US emissions standards for heavy-duty diesel engines are discussed in this paper. Manufacturers will most likely use a combination of technologies including reoptimized combustion chambers, fuel systems, air handling systems, electronic controls and aftertreatment. First year production incremental costs are estimated to range from between $257 and $467 to meet the new standards.

Road unevenness induces longitudinal as well as vertical forces in the suspension. The variation of vertical and longitudinal wheel forces can be of the same magnitude. Much work on vertical loads has been accomplished in heavy vehicle development, but less on longitudinal forces. Wheel forces have been measured on a semi-trailer tractor driven over a test track obstacle. The consistency of test results inspires confidence in the measured loads. Measured forces are compared with results from a simple simulation model. The influence of road-induced longitudinal forces on ride and chassis loads is demonstrated through simulations. The importance of longitudinal suspension compliance is discussed.

Meritor Heavy Vehicle Systems in conjunction with Detroit Diesel Corporation has developed an advanced patented shift system. The system monitors input and output speeds of the transmission, the neutral position of the shift lever, and the position of a ‘shift intent’ switch on the shift knob. The electronic controller processes this information and adjusts engine torque and speed to effect a shift of the manual transmission. This feature significantly reduces the driver workload while shifting.

Eaton has been working on technologies for cost effective, reliable and safe Automated Mechanical Transmissions (AMTs) since the mid 1970's. The company has introduced three different systems since the late 1980's, but all three systems were constrained by the lack of precise engine speed control during shifting. With the advent of electronic engine controls the constraint has been removed and precise engine speed control during shifting can be easily accomplished. The result is a simplified system that is powerfully intelligent and fully capable of automatic shifting i.e., the transmission system determines when to shift and executes the shift without any driver inducement across the broad spectrum of truck usage. This paper discusses some of the AMTs available to the truck market, showing how the system benefits both the OEM and the end user.

Basic lead-acid battery technology has remained virtually unchanged for almost 100 years. Although improvements have been made in chemistry and construction, the common causes that promote battery failure have remained the same. These causes are the result of sulfation buildup (crystallized sulfur molecules) on the battery plates. The most effective solution to this problem is pulse technology. Pulse technology helps eliminate battery failure by maintaining a higher active material processing area while creating a more consistent charge acceptance environment within the battery. As a result, productivity is improved, replacement and other battery-related expenses are avoided, and unnecessary negative environmental impact is averted.

An innovative Power Line Carrier (PLC) Communication system for video and digitally signal processed data distribution using the existing DC copper wire is presented. The major contribution consists of a new signal coupler that achieves a stable transmission bandwidth on the DC electrical lines. Several weeks of continuous beta tests achieved video transmission on the trucks +12V wiring (from the back of the truck to the driver's cabinet) and product manufacturing and delivery has started. Benefits include: simplicity of application; ease of implementation; effectiveness with video and data; applicability to all application types; elimination of coax and twisted pair wiring and its maintenance.

Use of power line technology is desirable for communication on vehicles, since it allows communication without adding wiring complexity beyond that provided by the electrical system, and furthermore allows easy retrofits. In some cases, mixed media systems may be optimal.

Multiplexed buses are necessary to add new electronic control systems on-board vehicles. With roughly 50% of these systems expected to be installed or modified after the vehicle rolls off the assembly line, plug-and-play retrofits are important. Using a network protocol that runs on the electrical wiring in a vehicle reduces wiring for new vehicles. In allowing use of wiring already installed on the vehicle, such a scheme also pays excellent dividends for retrofits. Over the life of a vehicle, networked electronic devices and sub-systems will be obtained from several different suppliers. Standard device profiles and a common network operating system are essential for their easy integration, whether on the assembly line or in the aftermarket.

A technique to compute vehicle weight (GVW or GCW) solely from measurements of force and acceleration taken onboard the tractor is described. A means to measure both variables by a single inexpensive sensor is disclosed, and algorithms are presented. Methods to compensate for real-world variables such as wind and grade are discussed, as are results obtained during 20,000 Km of testing. A potential means to determine GCW onboard the tractor without any additional hardware is presented. Applications, including ITS, are discussed, as are methods for instantaneous calibration.

The sounds traditionally used as auditory displays and warnings in truck cabs have no meaning outside the context of the particular environment in which they are used. If an operator changes equipment, often an entirely new set of warnings and the associations between the various sounds and the situations to which they refer must be learned, while at the same time long-standing associations learned from previous experience must be overcome. Furthermore, research has shown that people operating complex systems can effectively differentiate only five or six different alarm or warning sounds. In an attempt to overcome these shortcomings, a new class of auditory display, referred to as auditory icons, is being investigated. Whereas conventional auditory displays are defined by their particular acoustic parameters, auditory icons are caricatures of naturally occurring sounds. Such sounds are representational in that they have stereotypical meanings across large portions of the population.

Radar based collision warning systems (CWS) for heavy trucks have been in production and on the road in the United States for approximately two years. A short description of these systems is presented with actual driver performance data and accident reduction data as experienced by various U.S. national fleets using these systems. The next application of radar sensors is for Intelligent Cruise Control (ICC) or also known as Adaptive Cruise Control (ACC). This paper describes the operation of adaptive cruise control and presents the associated benefits to the driver The radar technology has been enhanced and the application has been extended to include radar controlled adaptive cruise control for heavy trucks This has been made possible by 1) technology improvements in radar systems, plus 2) the addition of the standard SAE J1939 data bus for engine controllers on most U.S diesel engines.

Caterpillar Fuel Systems is developing a family of next generation electronic unit injectors that provide the fundamental injection characteristics necessary for emissions and performance improvements for future direct-injection diesel engines. This paper describes the development and design of the mechanically actuated version of Caterpillar's advanced electronic unit injector fuel system to meet the engine customer driven requirements for enhanced injection characteristics with reliability and durability improvements.

The conventional diesel engine retarder is an add-on system that converts the power producing diesel engine into a power absorber by altering engine valve timing when vehicle retarding is desired. The retarding effect is achieved by releasing the compressed air charge near TDC compression to prevent energy from returning to the engine during expansion. Retarding performance is optimized only at one engine speed and the increased height due to the add-on approach is a disadvantage for some vehicle applications. This study introduces an integrated Variable Valve Timing (VVT) engine retarder (Figure 1) by applying the lost motion principle. The integrated retarding system has significant dimensional advantage over the conventional add-on engine retarder. The lost motion VVT retarder also provides optimized retarding performance over the entire engine operating range.

Although Hydrostatic Transmission System (HTS) had been used in many places, such as machine tools, agriculture machinery, construction machinery, and vehicles, it had not been used in good performance. Twenty years ago many people began to design new hydrostatic transmission with higher efficiency. Hydrostatic Energy Storage Transmission System (HESTS) is one of new hydrostatic transmission system with higher efficiency. HESTS is more fit for being used in vehicle that is always running in undulating ground or starting and braking frequently. Construction of vehicular HESTS was analyzed, mathematical model of vehicular HESTS was established. The needed control strategies of vehicular HESTS were analyzed because there are many variables would be controlled in the new transmission system.

A new method for detecting the low power conditions on electronically-controlled diesel engines used in on-road vehicles has been developed. The advantage of this method is that it uses readily available diagnostic tools and engine installed sensors with no necessity for a dynamometer test. Without removing the engine, it gives an estimate of the real engine power which is accurate to 5%.

A radically new approach to the design of bearings demonstrated feasibility in a U.S. Army SBIR1 program. It was first applied to universal joints on the HMMWV (High Mobility Multipurpose Wheeled Vehicle) in order to maximize the concept's performance benefits and optimize vehicle cost savings. The program2 was one of five recipients of the U.S. Army's 1995 SBIR Phase II Quality Awards. The concept has been issued three patents3. This paper presents the theory and documents HMMWV field test results in the successful development of a new universal joint with bearings that eliminate field lubrication and provide a major reduction in maintenance.