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Taking a good longitudinal braking performance on flat and level road of tractor and semi-trailer combination as a target, in order to achieve an ideal braking force distribution among axles, while the vehicle deceleration is just depend on the driver's intention, not affected by the variation of semi-trailer mass, the paper proposes a model based vehicle mass identification and braking force distribution strategy. The strategy identifies the driver's braking intention via braking pedal, estimates semi-trailer's mass during the building process of braking pressure in brake chamber, distributes braking force among axles by using the estimated mass. And a double closed-loop regulation of the vehicle deceleration and utilization adhesion coefficient of each axle is presented, in order to eliminate the bad effect of mass estimation error, and enhance the robustness of the whole algorithm. A simulation is conducted by utilizing MATLAB/Simulink and TruckSim.

Platooning is a key research area where increased focus and interest is shown in order to maximize the transport efficiency of road vehicles. Although the key benefits are projected as increased fuel efficiency especially when it comes to commercial vehicles, allied benefits such as convoy pack efficiency, traffic throughput rate, increased life cycle of components and a source of monetary benefit when using a subscription model are areas which need to be explored. Existing literature points to control strategies predominantly focused on longitudinal control and traffic management in bottlenecks.

The commercial vehicle industry is evolving faster with the rise in multifarious aspects deciding a company's progress. In the current scenario, vehicle performance and its reliability in the areas of payload, fuel economy, etc. play vital roles in determining its sustenance in the industry, in addition to reducing driver fatigue and improving comfort levels. Test quality and time is the key to assure and affirm, smooth and quick launch of the product into the market. This paper details on the design of Multi-Axis road data simulator which entails realistic loads onto the components for capturing meaningful information on behavior of the product and recreate the field failure modes. The design was conceptualized keeping in mind both cost (for initial installation and running cost) and time for testing without loss in the convergence factor.

An organic Rankine Bottoming cycle added to Diesel engines used for long-haul trucks has the potential of improving their peak fuel economy by up to 15% over a typical duty cycle. General Electric has developed a multi-vane rotary expander which has a measured isentropic brake efficiency of 80+% over a wide range of speed and power levels with organic working fluids. High cycle efficiency for design and off-design conditions is achieved with the multi-vane expander. The potential advantages of the multi-vane expander for the Diesel engine bottoming cycle include the elimination of a high speed gear box and the potential for over 80% isentropic engine efficiency. The multi-vane expander is a ruggedly built component running at Diesel engine speed. This paper describes the design and evaluation of a nominal 40 HP multi-vane expander for this application.

This study was undertaken to identify methods of unique identification of commercial vehicles at the roadside for slow and high-speed electronic screening purposes. It is a comprehensive look at available and emerging technologies, focusing on the needs of the Federal Highway Administration’s Office of Motor Carrier and Highway Safety (OMCHS) and the States. The study included both a needs assessment and a technology evaluation. A preliminary list of 22 technologies was developed that appeared to have some applicability to the task of roadside identification of commercial vehicles. As the technology evaluation progressed, five of these technologies (optical character recognition, radio frequency identification, barcode, image capture, and voice recognition) emerged as demonstrating the greatest potential for roadside identification of commercial vehicles. These five technologies were evaluated in some detail, and recommendations were developed.

The internal combustion engines emit combustion gases which contain nano and micrometric particles that are harmful to human health, causing deleterious damages to the human's respiratory system. In Brazil, heavy vehicles, such as buses and trucks, have diesel engines that work under high loads and run through metropolitan areas or in intense traffic flow roads. They are considered, nowadays, the main solid particles emitter in several World's areas. There are already standard systems to analyze these particles quantitative and qualitatively at high prices collected from vehicle gases emissions in places such as bus stops. This paper presents a new method which retains solid micrometric particulate matter emitted by diesel engine. It is simple and has a relatively low cost. A sheet of textile element was encapsulated in a system for gripping micrometric particles emitted by diesel single-cylinder engine operating in a bench and coupled with a electrical generator.

Recently most of the Japanese tractors (10 - 40kw) have been equipped with an electro-hydraulic system for automatic depth and tilt control for the rotary tiller. This is a typical implement for the Japanese rice farming. The improved performance was needed to deal in the following areas. 1. In the muddy and rough soil pan condition, the tillage depth has to be kept at the satisfactory level while the engine speed stays within the operating range. 2. An automatic depth control must apply to rough tillage without using the conventional depth sensor (i.e. rotary tiller rear cover angle sensor). To meet these requirements, an automatic depth and tilt control system was developed. The two control modes (called MC-AUTO and E-AUTO) for the automatic depth control were developed by combining the conventional control method plus a load control method based on the fuzzy control theory.

Liquid Crystal Display is in the process of achieving the supreme position as an automotive instrument panel; it will replace all other existing automotive displays on dashboards. However, a number of problems on technical support remain to be solved. Focused the most among them is the strong demand of a highly reliable connection method. The new connection technique by soldering was presented in the previous paper. This paper describes the reliability and fabrication process of the new connection and its application to Driver IC on flexible P.C.B. and Chip on Glass instrument panels.

A new transparent type electrochromic device (ECD) has been developed. It consists of two electrochromic thin films facing each other, one of “prussian blue” (PB) and the other of tungsten trioxide (WO3). PB exhibits a high intensity of coloration and is blue in the oxidized state and transparent in the reduced state. By electrodeposition, the PB layer can be formed on large substrates at low cost. This ECD has been applied to large, curved automotive glass. It reversibly turns from dark blue to transparent at low operating voltage and maintains the same intensity of coloration without the aid of an external power supply. Compared with photochromic glass, it achieves a greater color change in a shorter time and its light absorption can be changed at will. It shields passengers from the discomfort of glare and heat flow through glass.

A new concept in conventional truck cab vibration isolation has been developed by Holland Neway International. The system provides a significant improvement in ride comfort for the truck cab occupants in the truck of the twenty-first century. The single point isolator incorporates inclined sleeve type air springs to achieve a very low natural frequency, typically 0.9 - 1.1 hertz. A unique variable geometry damping system is used in conjunction with the sleeve springs to allow the configuration to achieve significant improvements in vibration isolation. The passive variable geometry control operates essentially undamped until large displacement disturbances are encountered allowing maximum possible isolation performance. Since the isolator natural frequency occurs in a region where the human physiology is most tolerant of vibratory motion, a high level of ride comfort is achieved.

Spicer has developed a new family of transmissions for the class 8 series truck. This paper describes the specifications, design features and thought processes that generated this new transmission design.

Transport vehicles consume a large amount of fuel with low efficiency, which is significantly affected by drivers' behaviors. An assessment system of eco-driving pattern for buses could identify the deficiencies of driver operation as well as assist transportation enterprises in driver management. This paper proposes an assessment method regarding drivers' economic efficiency, considering driving conditions. To this end, assessment indexes are extracted from driving economy theories and ranked according to their effect on fuel consumption, derived from a database of 135 buses using multiple regression. A layered structure of assessment indexes is developed with application of AHP, and the weight of each index is estimated. The driving pattern score could be calculated with these weights.

As long as a tire steers about a titled kingpin pivot, the point coming in contact with the road moves along its perimeter. This movement affects the determination of kingpin moments caused by the tire forces, especially for large steering angles. The movement, however, has been neglected in the literature on the steerable-tire-kinematics-related topics. In this investigation, the homogeneous transformation is employed to develop a kinematic model of a steering tire in which the instantaneous ground-contact point on the tire is considered. The moments about the kingpin axis caused by tire forces are then computed based on the kinematics. A four-wheel-car model is constructed for determining the kingpin moment of steering system during the low-speed cornering maneuver. The result shows that the displacement of the ground-contact point along the tire perimeter is significant for large steering angles.

Tracked vehicles are widely used for agriculture, construction and many other areas. Due to high emissions, hybrid electric driveline has been applied to tracked vehicles. The hybrid powertrain design for the tracked vehicle has been researched for years. Different from wheeled vehicles, the tracked vehicle not only requires high mobility while straight driving, but also pursues strong steering performance. The paper takes the hybrid track-type dozers (TTDs) as an example and proposes an optimal design of a novel power-split powertrain for TTDs. The commercial hybrid TTD usually adopts the series hybrid powertrain, and sometimes with an extra steering mechanism, which has led to low efficiency and made the structure more complicated. The proposed three-planetary-gear power-split hybrid powertrain can overcome the problems above by utilizing the characteristics of planetary gear sets.

The aerodynamic characteristics of automobiles have received substantial interest recently. Detailed knowledge of vehicle aerodynamics is essential to improve fuel efficiency and enhance stability at high-speed cruising. In this study, a numerical simulation has been carried out for three-dimensional turbulent flows around a commercial bus body. Also, the effect of a rear-spoiler attached at the rear end of the bus body was investigated. The Navier-Stokes equation is solved with the SIMPLE method in a general curvilinear coordinates system. RNG k- ε turbulence model with the MARS scheme was used for evaluating aerodynamic forces, velocity and pressure distribution. The results show that complex wake structure in the immediate rear of the bus body has been confirmed. The rear-spoiler modifies the near wake structure and decreases aerodynamic drag and improvement in lift force was achieved.

A Department of Energy funded research project currently in the final stages of completion has resulted in a web-based tool that gives non-expert users the ability to add aerodynamic devices to a CFD model of a single bogie trailer and generalized tractor model. This model was used to assess the aerodynamic performance of skirt geometries. The skirts were defined using 5 independent geometric parameters and 2 installation parameters. These parameters allow enough freedom in the geometry definition to capture the shape and installation position and angle of a wide number of commercially available skirts on the market today. Using a Design of Experiments approach, the aerodynamic drag response of the truck and trailer to any parametric change in the skirt geometry has been determined across a range of yaw angles.

Abstract To solve the problem that it is difficult for drivers to control the vehicle at low speed, a new setting scheme of pedal map is proposed to ensure that the vehicle has the speed controllability in the full speed range. In this scheme, based on obtaining the maximum and minimum driving characteristics of the vehicle and the driving resistance characteristics of the vehicle, the pedal map is divided into a sensitive area and insensitive area. In the insensitive area, acceleration hysteresis is formed, which ensures that the throttle is slightly fluctuated and has good speed stability. At the same time, the sensitive area of the accelerator pedal is formed far away from the driving resistance curve to ensure that the vehicle has a great acceleration ability. To verify the effectiveness of the proposed scheme, the data of a commercial vehicle is selected for the design of the pedal map, and the driver-vehicle closed-loop test based on the driving simulator is conducted.

Braking energy recovery can significantly contribute to fuel economy and emission reduction, particularly for commercial vehicles driving in urban environment. By using the compressed air storage, rather than expensive and vulnerable batteries, this paper proposes a pneumatic hybrid system with an integrated compressor/expander unit (CEU) for commercial vehicles, in order to achieve stop/start function and braking energy recovery. During braking, the compressed air is recovered by CEU working in compressor mode and is charged to the air tanks. When the vehicle starts from stop, the CEU works as an expander to crank the engine with compressed air. The compressed air can also be used to supply the air tank of brake boost system, thus reducing its energy consumption. The mathematical models of energy conversion units, including the two modes of CEU and the air brake system, are established and analyzed.

By coupling a Personal Computer to process 1/0 hardware and adding realtime multitasking software, a low cost automated data acquisition and control system can be assembled. This paper describes such a system built in a 19 inch rack on wheels which has been used for diesel engine testing. The system is readily reprogrammable to customize the function of the system to the job at hand.

Fuel cell engines are expected to deliver greater efficiency and lower emissions than conventional transit bus powertrains in the near future. Although experimental vehicles have demonstrated the emission and efficiency benefits of fuel cell power, the next step toward implementation is widespread fleet demonstrations to prove the technology in the field. In order to aid in the start of new demonstrations and speed fuel cell technology towards the fleet vehicle marketplace, an assessment of the needs, risks, and advantages of using fuel cell power must be obtained from a consumer perspective. It has been assumed that the increased fuel efficiency that is inherent to fuel cell systems will lower operating costs as compared with conventional diesel powertrains. A comparison of two fuel cell buses and a diesel bus was completed in order to quantify the operational cost benefits and identify potential cost deterrents to fuel cell bus implementation.