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Harmonization of systems and components leads to platform strategies within the truck industry as already known from the automotive industry. With respect to the Electrical- and Electronic Distribution System (EEDS) the investigations are focusing on common electrical systems and components, i.e. ECUs, sensors, actors, switches and connectors, to be used as carry-over parts in order to increase the volume and the quality and to reduce the cost. This investigation shows the different aspects and requirements on electronics and the Electrical Distribution System (EDS) within a communized electrical power supply. Finally a recommendation for best practices based on a currently available technology is given.

In this study, the air suspension is newly applied to the engine mounting layout for getting the significant vibration isolation effect. In this case, the genetic algorithm so called GA is also applied for the optimization of many parameters, calculations of stiffness matrix and inverse stiffness matrix to prevent the coupled vibration of lateral and rolling modes and to obtain the displacement of each mounting point. As a result, inexperienced engineers can easily obtain the optimum engine mounting layout in a minute. By the confirmation test of FEM, the engine lateral vibration level at 25Hz dropped below 1/10 and its effect was significant.

Dual clutch based transmissions (DCT) have been developed for passenger vehicles in Europe. Compared to a single clutch based transmission (SCT), DCT eliminates torque interrupts during gear-shifting so that the vehicles can run as smooth as one using an automatic transmission (AT). Traditionally AT needs to use torque converters to transmit engine torque to drivelines. However, a torque converter is complicated and expensive, and offers lower driveline efficiency than SCT and DCT. DCT technology is a cost-effective avenue to achieve smooth shifting while taking advantage of the some beneficial features of both AT and SCT. This paper presents the results of an analysis of the application of DCT on medium duty (MD) trucks. First, we set up a 6-speed DCT with two groups of three gear ratios in correspondence to two ceramic dry clutches. Clutch dampers are included in the DCT model. For simplicity but without loss of generality, the synchronizers are not included for this study.

Real-time theory is introduced to analyze reliability and robustness for ECU (Electronically Controlled Unit) of vehicle AMT (Automatic Mechanical Transmission). Real time analysis architecture is proposed. Analysis and simulation for the four working stages of AMT are illustrated. The results show, the real time system model with 9 tasks working on 4 processors is reasonable, and the designed Blended Timer-Triggered Scheduler is feasible as well as robust, which provide the system more extendibility and reliability.

Carbon based friction materials continue to gain increasing acceptance in many friction applications. One unique class of carbon based friction materials is Chemical Vapor Deposited carbon fabric (CVD Fabric™) Since 1991, CVD Fabric™ has been used in production automotive wet friction applications including limited slip differentials and heavy and medium duty truck transmission synchronizers. It offers stable friction levels, low wear rates and is readily wetted by transmission oils. Because CVD Fabric does not soften with temperature and is unaffected by solvents, this high energy absorption, high abuse tolerant material may provide significant performance advantages in off-highway wet brake and clutch applications. This paper will explore the Physical, mechanical and tribological properties of CVD Fabric wet friction materials.

The on-road lateral stability of an articulated steer vehicle is investigated for both small and high deviations. First, for small deviations, a linear model of the vehicle is devised and analyzed. This planar model is generated based on some simplifying assumptions. For instance, the equations describing the tire forces and moments are linearized, and the tire rolling resistance is neglected. A linear stability analysis of the straight line motion of the vehicle with constant forward speed is conducted by using this simplified model for different values of the torsional stiffness and damping at the articulation joint. To investigate the lateral stability of the vehicle at higher deviations, the motion of a virtual prototype of the vehicle in ADAMS/View is simulated for different conditions. Finally, the results from the simulations and the linear stability analyses are compared.

The present article looks into possibilities for using drive axle semiactive suspension systems of a tractor in a tractor-semitrailer combination. The problem has been studied by means of computer-aided simulation, with ADAMS/Car MSC software. The shock absorbers of the semiactive suspension are provided with closed-loop preview control. Thus, the steering front axle of the tractor functions as a sensor to register road irregularities that the wheels of the drive axle should overcome. There has been suggested a simplified control logic for the semiactive suspension, being based on the outcomes of the study of the closed-loop preview control algorithm. When used for the drive axle of the tractor in the tractor-trailer combination, the semiactive suspension has been demonstrated to reduce the coefficient of variation of dynamic vertical forces on road pavement by 5,5 to 7%, in comparison with the conventional suspension types.

Transient fluid slosh within a partly-filled tank could impose high stresses on the tank structure and affect the directional performance in an adverse manner. A three-dimensional nonlinear model of a partly filled circular cylindrical tank with and without baffles is formulated and analyzed to derive the pressure distribution over the wetted tank surface. The baffles and end caps are modeled with curved shapes in accordance with the current standard. The analyses are performed for 40% and 60% fill volumes and different types of baffles, including single-nozzle and multiple-orifice baffles, using the FLUENT software under time varying acceleration fields representing simultaneous braking and turning maneuvers. The pressure data are further analyzed to evaluate steady-state and transient slosh forces, load shifts along the longitudinal and lateral axes, and the roll, pitch and yaw moments imposed on the tank structure.

Two different concepts in hydro-pneumatic suspension struts are formulated to conveniently realize either hydraulic or pneumatic interconnections between the struts within different wheel suspensions. The formulation employs a compact strut design that integrates a gas chamber and damping valves within the same unit, and provides considerably enhanced working area to appreciably reduce the operating pressure. A transverse interconnection between the hydro-pneumatic struts in the roll plane is analyzed to investigate its static and dynamic heave and roll properties, and relative potential benefits in enhancing the roll properties, while retaining the soft heave ride. Different hydraulically and pneumatically interconnected strut configurations are analyzed for a heavy vehicle, with appropriate considerations of the fluid compressibility, while the feedback effects associated with the interconnections are emphasized.

As regulations for on-board diagnostics head toward the heavy-duty trucking industry, there are a variety of new communication concepts that will directly impact J1939 systems. ECUs on J1939 networks must support new standard diagnostic protocols and data. Vehicles must provide single-point access for concise OBD data sets that represent multiple ECUs. New technologies, such as wireless communication links, present completely new and different scenarios for diagnostic testing. Understanding these concepts and their implications is essential to designing a J1939 system that will integrate into the coming global OBD infrastructure.

Heavy-duty diesel on-board diagnostics (OBD) regulations are being phased in around the world with varying degrees of similarity. This is occurring at a time when heavy-duty diesel emission regulations are driving complex and elaborate emission control strategies. Unique circumstances led the European heavy-duty diesel market to adopt selective catalytic reduction (SCR) as the primary solution for meeting strict Euro 4 emission levels. This paper is a review of the challenges of diagnosing an SCR system based on the Euro 4 OBD regulation and considers the future challenges of SCR diagnostics that lie ahead in the North American market.

With the increase of operating temperatures and equipment availability, the need is emerging for hydraulic and lubricating equipment manufacturing companies to include new proactive parameters in their maintenance specifications. Not only will these parameters result in a better balance between equipment and oil health monitoring, but also increase the availability of the equipment. The first part of this paper will present principles of working for this innovative technique, (off-line as well on-line oil analysis information) to monitor the antioxidant concentration or oxidative health of the oil, as a complementary parameter to contamination analysis. The second part of the paper will highlight the capability of the RULER™, as a portable field technique for different case studies. By monitoring the antioxidant depletion end-users will avoid excessive base-oil degradation and/or varnish and lacquer formation as well abnormally operating systems.

Regulatory authorities are actively revising and updating the rules for on board diagnostics of diesel powertrains. Diesel oxidation catalysts are among the parts that will have to be monitored. This paper discusses some of the issues related to the feasibility of monitoring these catalysts. We concentrate on the effect of real world noise factors on the ability to distinguish marginal from threshold catalysts and demonstrate that with current sensor and catalyst technology the separation between the two is poor.

To remove the snaking mode of an articulated steer vehicle, an active steering system is proposed. First, the existing steering systems of articulated steer vehicles, including hydraulic-mechanical and hydrostatic steering systems, are reviewed. Then, a combined linearized model of the vehicle with a hydraulic-mechanical steering system is developed. By using this model, two passive methods to decrease the snaking, including an increase in the friction at the articulation joint and leakage across the cylinders are detailed. To overcome the shortcomings of these solutions, an active steering system is also introduced. It is shown that the proposed steering system not only removes the instability, but also improves the steering response of the vehicle.

Hydraulic fluid (HF) specifications for mobile construction equipment called JCMAS HK and HKB have been established by the Fuels and Lubricants Committee of Japan Construction Mechanization Association (JCMA). The specifications are designated by two viscosity categories of single grade and multigrade. Each category has ISO viscosity grade (VG) 32 and 46. The JCMAS HK oils are recommended for use in hydraulic systems designed at pressure up to 34.3MPa(5000psi) and to heat hydraulic fluid up to 100 °C. These oils also provide wear control, friction performance, oxidation and rust protection, seal swell control and filterability performance. Two piston pump test procedures were developed to evaluate lubricating performance of these oils under high pressure conditions. The JACMAS HKB oils are classified as environmentally friendly oils due to the additional requirement for biodegradability.

On-road emission measurements of 23 VN-trucks on a randomly chosen driving cycle, consisting of 10 miles two-lane and 8 miles four-lane road, showed tailpipe NOx emissions on fleet average of 0.96 g/bhp-hr, or 1.06 g/bhp-hr when including the time the exhaust gas temperature was below 200°C. Complementary measurements in a SET-cycle (13 point OICA -cycle) on a chassis dynamometer showed a tailpipe emission of 0.008 g PM per bhp-hr. Moreover, cost analysis show that the diesel fuel consumption remains unchanged whether the truck running on ULSD is equipped with a Combined Exhaust gas AfterTreatment System (CEATS) installed or not.

The dynamic behavior of heavy vehicles moving on roads depends on load magnitude and its distribution, and a special concern may be directed to tankers. Liquid cargo at partial filled levels exhibits sloshing during vehicle longitudinal displacement, generating some forces which might alter vehicle's directional response and traction control. To attenuate the sloshing dynamic effect, transversal plates (baffles) are placed inside the container but increasing the structural container mass, arising vehicle's mass center and decreasing vehicle's useful load capacity. An experimental study on the effects of fill level and number of baffles on the sloshing attenuation is presented. For doing so, an instrumented scaled experimental tank of elliptical transversal section is used with water as liquid cargo, and longitudinal sloshing force is measured.

The future of vehicle safety will benefit greatly from precrash detection - the ability of a motor vehicle to predict the occurrence of an accident before it occurs. There are many different sensor technologies currently available for pre-crash detection. However no single sensor technology has demonstrated enough information gathering capability within the cost constraints of vehicle manufacturers to be used as a stand alone device. A proposed solution consists of combining information from multiple sensors in an intelligent computer algorithm to determine accurate precrash information. In this paper, a list of sensors currently available on motor vehicles and those that show promise for future development is presented. These sensors are then evaluated based on cost, information gathering capability and other factors.

Field testing of an extended life coolant technology in Class 8 trucks, equipped with Caterpillar C-12 engines revealed excellent coolant life with negligible inhibitor depletion to 400,000 miles with no refortification and no coolant top-off. In separate evaluations in Caterpillar 3406E equipped trucks, extended corrosion protection and component durability were established out to 700,000 miles, without the need for refortification other than top-off.

In this paper finite element model of porous materials is used to improve the acoustical behavior of vehicle sound absorbers. The equation of wave propagation in the porous materials with rigid frame is presented after explaining the physical properties of these materials. The finite element formulation of governing equation and boundary conditions is obtained based on Galerkin method. Simulation results are compared with the corresponding results of the other validated papers and also verified by analytical results. Finally, effects of physical and geometrical parameters on the acoustical behavior of absorbers are studied. In addition, the influence of an air gap on the back of the material and also multilayer absorbers are investigated. It is shown that the acoustical behavior of these materials, particularly in the low frequency range, can be improved.