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Hybrid electric vehicles (HEVs) are worldwide recognized as one of the best and most immediate opportunities to solve the problems of fuel consumption, pollutant emissions and fossil fuels depletion, thanks to the high reliability of engines and the high efficiencies of motors. Moreover, as transport policy is becoming day by day stricter all over the world, moving people or goods efficiently and cheaply is the goal that all the main automobile manufacturers are trying to reach. In this context, the municipalities are performing their own action plans for public transport and the efforts in realizing high efficiency hybrid electric buses, could be supported by the local policies. For these reasons, the authors intend to propose an efficient control strategy for a hybrid electric bus, with a series architecture for the power-train.

A Microprocessor Data Acquisition System has been designed to be cab-mounted in vehicles or used in laboratories to acquire up to 16 channels of test data. This data may be acquired as time-at-level histograms in one or two dimensions with min-max-mean data recovery, time histories, or peaks and valleys stored on digital tape. The system includes a microcomputer-based Playback/Support Box that simplifies playback of data tapes for computer analysis or stand-alone data plotting using a graphics terminal.

The University of Maryland team converted a model year 2000 Chevrolet Suburban to an ethanol-fueled hybrid-electric vehicle (HEV) and tied for first place overall in the 2000 FutureTruck competition. Competition goals include a two-thirds reduction of greenhouse gas (GHG) emissions, a reduction of exhaust emissions to meet California ultra-low emissions vehicle (ULEV) Tier II standards, and an increase in fuel economy. These goals must be met without compromising the performance, amenities, safety, or ease of manufacture of the stock Suburban. The University of Maryland FutureTruck, Proteus, addresses the competition goals with a powertrain consisting of a General Motors 3.8-L V6 engine, a 75-kW (100 hp) SatCon electric motor, and a 336-V battery pack. Additionally, Proteus incorporates several emissions-reducing and energy-saving modifications; an advanced control strategy that is implemented through use of an on-board computer and an innovative hybrid-electric drive train.

The 14/42V Electrical System Architectures have been the subject of discussions in many technical meetings. Some of the major challenges are: system cost, mixed load handling flexibility, jump start issue, battery service life, and transient voltage under load dump situation. In this paper, a patented, bi-directional, charge-transfer circuit is evaluated against these criteria. Circuit performance is discussed in details. It covers circuit efficiency, battery voltage ripple, and transfer-current ripple, and the effectiveness of balancing the battery voltages under various mixed 12/36V loads. The energy transfer principle between a 14V system and a 42V system is presented to demonstrate the cross jumping and surge-load handling capability. The bi-directional energy transfer capability of the circuit easily keeps the load-dump transient-voltage under the 58V limit with either the 14V or the 28V batteries are disconnected.

This paper addresses challenges in current Fuel Cell Stack Buses and presents a novel Fuel Cell Electric Vehicle Bus (FCEV-Bus) powertrain that combines fuel cells, ultra-capacitors, and batteries to enhance performance and reliability. Existing Fuel Cell Stack Buses struggle with responsiveness, power fluctuations, and cost-efficiency. The FCEV-Bus powertrain uses a Fuel Cell stack as the primary power source, ultra-capacitors for quick power response, and batteries for addressing power variations. Batteries also save costs in certain cases. This combination optimizes power management, improves system efficiency, and extends the FCEV-Bus's operational life. In conclusion, this paper offers an innovative solution to overcome traditional fuel cell system limitations, making FCEV-Buses more efficient and reliable for potential wider adoption.

Batteries are widely used as storage devices and they have recently gained popularity due to their increasing smaller sizes, lighter weights and greater energy densities. These characteristics also render them suitable for powering electric vehicles. However, a key gap exists in that batteries are solely used as storage devices with a lack of information flow. Next-generation battery technologies will constitute the enabling tools that would lead to information-rich batteries, thus allowing the transparent assessment of a battery's health as well as the prediction of a battery's remaining-useful-life (RUL) and its subsequent impact on vehicle mobility. Various methods and techniques have been employed to predict battery RUL in order to improve the accuracy of the State of Charge (SoC) estimation.

In order to reduce fuel consumption, companies have been looking at hybridizing vehicles. So far, two main hybridization options have been considered: electric and hydraulic hybrids. Because of light duty vehicle operating conditions and the high energy density of batteries, electric hybrids are being widely used for cars. However, companies are still evaluating both hybridization options for medium and heavy duty vehicles. Trucks generally demand very large regenerative power and frequent stop-and-go. In that situation, hydraulic systems could offer an advantage over electric drive systems because the hydraulic motor and accumulator can handle high power with small volume capacity. This study compares the fuel displacement of class 6 trucks using a hydraulic system compared to conventional and hybrid electric vehicles. The paper will describe the component technology and sizes of each powertrain as well as their overall vehicle level control strategies.

For several staged collisions, results obtained with closed form reconstruction calculations and with a computerized step-by-step procedure are compared with measured responses. A refined, closed-form reconstruction procedure is defined, derivations of the analytical relationships are outlined and detailed results of sample applications are presented. Closed form calculation procedures for estimating impact conditions became a topic of interest in relation to the development of an automatic starting routine for iterative applications of the Simulation Model of Automobile Collisions (SMAC) computer program. The accuracy of initial estimates of speeds determines the total number of iterative adjustments of SMAC that are required to achieve an acceptable overall match of the evidence. Since a high degree of success was achieved in the refinement of such calculation procedures, the end product, by itself, is considered to be a valuable aid to accident investigations.

Frequency domain testing has had limited use in the past for durability evaluations of automotive components. Recent advances and new perspectives now make it a viable option. Using frequency domain testing for components, test times can be greatly reduced, resulting in considerable savings of time, money, and resources. Quality can be built into the component, thus making real-time subsystem and full vehicle testing and development more meaningful. Time domain testing historically started with block cycle histogram tests. Improved capabilities of computers, controllers, math procedures, and algorithms have led to real time simulation in the laboratory. Real time simulation is a time domain technique for duplicating real world environments using computer controlled multi-axial load inputs. It contains all phase information as in the recorded proving ground data. However, normal equipment limitations prevent the operation at higher frequencies.

On January 10th, 1972, an S. A. E. Paper “Lighting System Performance and the Computer as a Maintenance Tool” (720087) was presented by Charles J. Owen. This was a paper presented on the causes, effects, corrections and a study in good and bad electrical wiring, presented pictorially as well as editorially. We recommend that paper to you for reading. On November 4th, 1974, S. A. E. Paper “A Case for Standardization” (741143) was presented by Charles J. Owen. The purpose of this paper was intent on “improving the breed”. The recommendations and specifications were very specific. In view of the two previous papers, this paper is presented specifically for the designer with back-up data involving recommendations that the industry have generally accepted as applied to the electrical wiring systems The practical data included, is a first in relating indexes of performance and indexes to cost comparisons. The usefulness of this paper in aiding a Designer is the target of the authors.

Diesel powered vehicles are characterized by two distinctives, of particulate, sensed by sight, and odor, sensed by smell. Dramatically reducing these distinctives would result in a “clean diesel”. A joint program of Yellow Freight System, Inc. (YFS) and the author's employer (DCI) has addressed one distinctive (particulate) and has resulted in an exhaust filtering system for the diesel forklift trucks YFS use to move freight at their terminals. This paper covers design, installation, and testing of the system to filter the particulate emissions emanating from these forklifts. The filters, designed to operate for one programmed maintenance (PM) cycle, are then cleaned in off-board equipment and returned to service for another cycle. All filter materials utilized are compatible with the 200°C normal maximum operating temperature, although short excursions to 260°C have not been detrimental.

A multi-year Power System R&D project was initiated with the objective of developing an off-road hybrid heavy-duty concept diesel engine with front end accessory drive-integrated energy storage. This off-road hybrid engine system is expected to deliver 15-20% reduction in fuel consumption over current Tier 4 Final-based diesel engines and consists of a downsized heavy-duty diesel engine containing advanced combustion technologies, capable of elevated peak cylinder pressures and thermal efficiencies, exhaust waste heat recovery via SuperTurbo™ turbocompounding, and hybrid energy recovery through both mechanical (high speed flywheel) and electrical systems. The first year of this project focused on the definition of the hybrid elements using extensive dynamic system simulation over transient work cycles, with hybrid supervisory controls development focusing on energy recovery and transient load assist, in Caterpillar’s DYNASTY™ software environment.

The paper proposes a method to analyze a trade-off between IC engine and electric battery sizes which is the essential issue of plugin hybrid and range extended electric vehicle design. This method implies a set of maps to be elaborated from batch simulations of hybrid vehicle running a driving cycle. Said maps establish relationships between ICE power, fuel consumption, electric energy consumption, and driving range of a vehicle. From these, one can choose a combination of ICE power and battery energy content meeting specific requirements for fuel economy and driving range. Mathematical model of the vehicle and the hybrid powertrain adopted for driving cycle simulations is described. Besides vehicle dynamics and drivetrain’s powerflows, it addresses battery’s current and voltage restrictions, which define performance of an electric drivetrain and have to be taken into account when selecting ICE power.

There are several existing and emerging alternatives to lead acid batteries to provide backup energy storage for remote powering applications. These alternatives include generator sets, flywheel systems, turbine alternators, fuel cells, and superconducting magnetic energy storage (SMES). Flywheels offer dramatic improvements in performance, require little maintainance, are environmentally friendly in reliability, maintenance, lifetime, and cost over these energy storage technologies. High strength fiber composites, high efficiency electric drives, and frictionless magnetic bearings along with the declining size and cost of electronics have made these advanced flywheels.

Low temperature Diesel exhaust operations such as during low-load cycles are some of the most difficult conditions for SCR of NOx. This, along with newer regulations targeting substantial reduction of the tailpipe NOx such as California-2024/2027 NOx regulations, adds to challenges of high efficiency SCR of NOx in low temperature operations. A novel design, low-cost, low-energy Electrically Heated Mixer (EHM™), energized via the 12, 24 or 48 V vehicle electrical system, is used to accelerate formation of reductants (ammonia, isocyanic acid) in low temperature exhaust (low load cycles), so to enable high efficiency SCR of NOx in most challenging SCR conditions, while also mitigating urea deposit formation. EHM™ is also used to heat the cooler exhaust flow during engine cold-start. It easily fits common exhaust configurations and can be utilized on light, medium or heavy duty Diesel aftertreatment systems, on- or non-road or in stationary systems.

It is apparent that a new generator and regulator design is needed to supply the additional electrical loads and meet the requirements for durability, reliability, and environmental protection on earthmoving equipment. The author discusses the d-c and alternator type systems which have been used to supply electrical needs. A detailed analysis of the integral charging system is presented. This system overcomes many of the shortcomings of the present electrical systems and, because it has a minimum number of moving parts, it is potentially the most reliable charging system in use on heavy duty equipment.

In today's vehicle, the electrical power distribution panel becomes the circuit protection, relay, and wire management center for the entire electrical system. This paper describes a new 3-D electrical distribution concept and presents a supporting design. The proposed design establishes circuits for connecting power inputs, outputs, and top loaded pluggable components by modifying a standardized flat conductive grid. The grid includes a repeating pattern of connecting rings and radial spokes. These spokes define circuit paths extending from and interconnecting each ring. At the final stages of manufacturing, the required circuit paths are created on a single sheet by selectively removing certain spokes. Multiple sheets are stacked with insulating barriers located between each layer. An interconnection between layers is realized by selectively positioning connecting pins through the ring nodes and interconnecting circuits defined on successive layers.

In order to improve the fuel economy of the heavy duty trucks at a highway driving condition, the heavy duty hybrid trucks with new type of hybrid electric assist engine system were proposed at the previous report. The new system consists of a downsizing diesel engine with a two-stage charging structure, which has an electric supercharger with bypass circuit and a conventional turbocharger, the hybrid electric motor and the small-capacity battery. The electric power consumption of an electric supercharger is equivalent to the amount of the regeneration power produced during high-speed driving where the opportunity of the regeneration is small. In this report, an electric supercharger for the heavy duty hybrid truck was produced experimentally. First, the engine performance and exhaust emissions were investigated using the 4 cylinder diesel engine equipped with an electric supercharger.

Adaption of EV powertrains in existing vehicle architecture has created many unique challenges in meeting performance, reliability, safety, ease of manufacturing & serviceability at optimum cost. Mounting of large size battery packs in existing vehicle architecture is one of them. Specific energy & the energy density of Lithium ion batteries are very lower compared to Diesel & Petrol, which requires high volume & weight for equivalent energy storage. For movement of many passengers and to ensure sufficient range EV buses typically needs large amount of energy and for storage of same bigger size battery packs are required. These large size batteries directly affect vehicle architecture, seating layout, ease of assembly & serviceability. Moreover the heavy mass of batteries directly influences vehicle dynamics & performance characteristics such as vehicle handling, roll & NVH. The most important consideration in design of EV vehicles in general and buses in specific is safety.

This paper presents a technical, financial and environmental analysis of four different hybrid buses operated under Buenos Aires driving conditions. A conventional diesel bus is used as reference and three electric hybrids equipped with different energy storage technologies, Li-Ion, NiMH batteries and double layer capacitors (ultracapacitors), are evaluated, along with a hydraulic hybrid platform which uses high-pressure accumulators as its energy buffer. The operating conditions of the buses are set using real driving GPS data collected from various bus routes within the city. The different vehicle platforms are modeled on AUTONOMIE SA and validated by comparing the obtained fuel consumption results to those reported by local transport authorities and values found in the literature. The embedded energy and CO2 emissions of each platform are estimated using GREET and the total cost of ownership of each vehicle is calculated and compared to that of the conventional bus.