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This paper presented a brief derivation of the energy dissipation by vehicle shock absorbers. Analysis between energy dissipation and damping coefficient, the road displacement power spectral density, the vehicle speed and the tire stiffness was carried out. Then an energy recovery scheme was put forward, and the bench test proved that the energy harvest scheme is feasible. In the end, this paper provided detailed derivation of the characteristics of the hydraulic electromagnetic energy-regenerative shock absorber, which increases its feasibility and practicability.

The consumption of fossil fuels is one of the largest problems facing humankind. One of the heaviest users of non-renewable energy sources is the transport industry. Tightening worldwide legislation aims to place restrictions on the transport industry to reduce its use of fossil fuels and reduce the levels of pollution being released to the atmosphere. Although several different alternatives to the vehicles only powered by internal combustion engine (ICEs) have been investigated, none have as yet become equally widespread. Alternative research into development of hybrid vehicles was specifically concerned with electric hybrids especially for passenger vehicles. Currently there is a resurgence of interest in the Hybrid Hydraulic Vehicle (HHV) in application to commercial and to a lesser degree to passenger vehicles. This paper gives an overview of hydraulic hybrid technology.

The advancement of computer systems and simulation modeling tools have enabled control systems designers to reduce the development time and bring active safety system products to market faster. Modern tractor-trailers are becoming increasingly equipped with such active safety systems. More often than not, these tractor-trailers are designed to pull either a single trailer or multiple trailers in operation. One of such multiple trailer combinations are the B-Doubles combination, in which the fifth wheel coupling is located at the rear of the lead, trailer, which is mounted on the rear section located immediately above the lead trailer axles. Although this combination is less susceptible to lateral instability compared with an A-Train combination, it can still have exposure to roll instability. Hence, the application of a trailer roll stability system on the combination vehicle may prove beneficial to the roll stability.

The thermal systems of commercial vehicles are changing to reduce operational costs and tailpipe CO₂ emissions and to address anti-idling legislation. As these systems transition they must recognize that waste heat from the internal combustion engine can longer be the only means of providing hot coolant for heating. The Unitary HPAC (Heat Pump Air Conditioner) provides the hot coolant needed for heating in addition to cold coolant that can be used for cooling. The Unitary HPAC is a refrigerant system that is coupled with a coolant system. It produces hot and cold coolant that is used to manage the vehicles thermal needs. It has the ability to scavenge heat from unused sources, which allows it to provide heating with COP's (Coefficient of Performance) greater than 1. The Unitary HPAC can be applied to any vehicle that does not have enough hot coolant available for heating purposes.

The quality of the brake system is a significant safety factor in commercial vehicles on the roads. With the development of automobile technology, the single function ABS system didn't meet active safety requirements of the user. The Electronically Controlled Brake System (EBS) system will replace the ABS system to become the standard safety equipment of commercial vehicles in the near future. EBS can be said an enhanced ABS system, it contains load sensor, brake valve sensor and pressure sensor of chamber, etc, and it is more advantages than ABS. This paper describes a flexible integrated test bench for ABS/EBS Electronic Control Unit (ECU) based on Hardware-In-the-Loop (HIL) simulation technique. It consists of most commercial vehicle pneumatic braking system components (from brake pedal valve, brake caliper to brake chambers), and uses the dSPACE real-time simulation system to communicate to the hardware I/O interface.

The heavy-duty diesel industry continues to expand the use of sophisticated electronic controls to reduce greenhouse gas emissions and improve fuel economy in the transportation sector. This inevitably leads to a need for increased knowhow in all aspects of embedded software development, e.g. in writing model-based specifications, rapid controls prototyping, automatic code generation, and hardware-in-the-loop (HiL) testing. In addition, the software development organization has to recognize the need to establish maturity in its verification and validation test framework, which includes, among other things, a proper definition of testing process and workflow, greater organizational focus, and a robust tool architecture for software testing. Navistar has already undertaken a model-based approach to software development and continues to improve their processes, technology, and tooling in this area.

The introduction of stringent EPA 2015 regulations for locomotive / marine engines and IMO 2016 Tier III marine engines initiates the need to develop large diesel engine aftertreatment systems to drastically reduce emissions such as SOx, PM, NOx, unburned HC and CO. In essence, the aftertreatment systems must satisfy a comprehensive set of performance criteria with respect to back pressure, emission reduction efficiency, mixing, urea deposits, packaging, durability, cost and others. Given multiple development objectives, a systematic approach must be adopted with top-down structure that addresses top-level technical directions, mid-level subsystem layouts, and bottom-level component designs and implementations. This paper sets the objective to provide an overview of system development philosophy, and at the same time touch specific development scenarios as illustrations.

The problem with traditional drive cycle fuel economy analysis is that kinematic (backward looking) models do not account for transient differences in charge air handling systems. Therefore, dynamic (forward looking) 1D performance simulation models were created to predict drive cycle fuel economy which encompass all the transient elements of fully detailed engine and vehicle models. The transient-capable technology of primary interest was mechanical supercharging which has the benefit of improved boost response and "time to torque." The benefits of a supercharger clutch have also been evaluated. The current US class 6-8 commercial vehicle market exclusively uses turbocharged diesel engines. Three vehicles and baseline powertrains were selected based on a high-level review of vehicle sales and the used truck marketplace. Fuel economy over drive cycles was the principal output of the simulation work. All powertrains are based on EPA 2010 emission regulations.

Selective catalytic reduction (SCR) technology is capable to deliver significant reduction of NOx emissions from diesel engines. This system relies on the use of urea as a reductant that is sprayed into the exhaust flow before reaching the ceramic substrate containing the SCR catalyst. This study describes the effect of urea exposure on substrate support mats when installed in full scale SCR units. Individual systems were aged to 500, 1000, 2000 and 3500 hours. After the aging was completed the devices were torn down and testing was completed on the mat and substrate. Tests were performed to search for the presence of crystalline urea inside the support mat fiber matrix and several analytical tests were performed to determine whether urea exposure and built up caused deterioration of mat pressure and its long term durability.

With the emission norms becoming more and more stringent along with the focus on reducing ownership and operating costs, the need to optimize the aftertreatment system becomes much more evident. Thus, the well monitored, optimized usage of urea or ammonia (NH₃) for the NOx reduction in an SCR system is critical to reduce the operating cost of the vehicles and to comply with emission regulations. In Ammonia Storage and Delivery System (ASDS), pure gaseous NH₃ from the NH₃ cartridges is being used for the reduction of the engine-out NOx in the exhaust stream over the NPF (NOx Particulate Filter). In almost all NOx reduction systems, NOx sensors play an important role in determining the amount of urea or NH₃ to be dosed for efficient NOx reduction with minimal NH₃ consumption and slippage for best possible fluid economy.

As emissions regulations around the world become more stringent, emerging markets are seeking alternative strategies that align with local infrastructures and conditions. A Lean NOx Catalyst (LNC) is developed that achieves up to 60% NOx reduction with ULSD as its reductant and ≻95% with ethanol-based fuel reductants. Opportunities exist in countries that already have an ethanol-based fuel infrastructure, such as Brazil, improving emissions reduction penetration rates without costs and complexities of establishing urea infrastructures. The LNC performance competes with urea SCR NOx reduction, catalyst volume, reductant consumption, and cost, plus it is proven to be durable, passing stationary test cycles and adequately recovering from sulfur poisoning. Controls are developed and applied on a 7.2L engine, an inline 6-cylinder non-EGR turbo diesel.

The Urea-SCR system has been widely used for the after-treatment of NOx to meet tighter regulations for the heavy-duty diesel engine. In addition, the long useful life time of heavy duty engines requires the highly durable components of urea-SCR system such as the catalyst and urea-dosing unit. This paper focused on the deactivation of the SCR catalyst for the EURO4 engine. The NOx conversion of field-aged catalysts was monitored with certain mileage accumulation at the engine bench and laboratory reactors. The postmortem analysis of the catalysts has been carried out to investigate the possible deactivation routes of SCR catalysts in the real driving condition. The analysis showed that the SCR catalyst was durable enough to meet the legislations over the useful lifetime of the engine and found that the non-thermal mechanisms such as poisoning were major routes for the deactivation of catalysts while the thermal sintering was shown to be marginal.

The current legislation for industrial applications and construction equipment including earthmoving machines and crane engines allows different strategies to fulfill the corresponding exhaust emission limits. Liebherr Machines Bulle SA developed their engines to accomplish these limits using SCRonly technology. IAV supported this development, carrying out engine as well as SCR aftertreatment system and vehicle calibration work including the OBD and NOx Control System (NCS) calibration, as well as executing the homologation procedures at the IAV development center. The engines are used in various Liebherr applications certified for EU Stage IIIb, EPA TIER 4i, China GB4 and IMO MARPOL Tier II according to the regulations “97/68/EC”, “40 CFR Part 1039”, “GB17691-2005” and “40 CFR Parts 9, 85, et al.” using the same SCR hardware for all engine power variants of the corresponding I6 and V8 engine families.

With introductions of stringent diesel engine emission regulations, the DOC and DPF systems have become the mainstream technology to eliminate soot particles through diesel combustion under various operation conditions. Urea-based SCR has been the mainstream technical direction to reduce NOx emissions. For both technologies, low-temperature conditions or cold start conditions pose challenges to activate DOC or SCR emission-reduction performance. To address this issue, mini or full flow burner systems may be used to increase exhaust temperature to reach DOC light-off or SCR initiation temperature by combustion of diesel fuel. In essence, the burner systems incorporate a fuel injector, spray atomization, proper fuel / air mixing mechanisms, and combustion control as independent heat sources.

Non-road machineries cover a large variety of platforms requiring aftertreatment strategies which are different from those utilized in on-road platforms. The right choice of an aftertreatment strategy is complex due to the consideration of engine power rating, duty cycle, durability and regulatory requirements as well as fuel economy concerns and total operating costs. Some powertrain systems utilize merely a DOC-SCR aftertreatment system, with or without EGR, depending upon engine-out versus targeted tailpipe NOx emission. This strategy necessitates integrating a urea (DEF/AdBlue®) injection system. When combined with moderate EGR, the requirements on NOx conversion efficiency can be reduced below 90%. Without EGR, a conversion efficiency about 95% is required. Some other platforms intend to use a DOC-DPF system, along with a "high PM" approach on the NOx/PM trade-off.

EGR coolers are widely used in reciprocating engines to reduce NOx emission. Thermophoresis-an important transport mechanism for submicron particles such as soot-drives gas-suspended particles from hot regions towards cool surfaces and is responsible for soot deposition and build-up in EGR coolers and related devices. Although much is known about thermophoresis in steady flow, little is known about soot deposition in flows with oscillatory heat and mass transfer. In this paper we present new results for the model problem of thermophoretic particle transport in a thin pulsatile shear layer above a flat, cold wall. The transport equations for this sublayer flow with oscillating shear have been solved numerically and, in the case of steady flow, are in excellent agreement with the exact solution for the steady wall shear.

Out of necessity, emission and fuel consumption test cycles are a simplified representation of the real-life use of a vehicle or component that is assumed to be most common. In reality, variations are introduced by both the driver and the environment - and to a lesser degree also by the vehicle itself through performance deviations because of tolerances in the components' characteristics. However, since such simplified test cycles exist and are accepted (or even required by law), OEMs tend to use them also in product development to benchmark their products against the competition, and to make decisions on how to optimize design. While this approach might give acceptable results for on-road vehicles, it fails to capture reality in the case of versatile working machines. Here, the variety of possible applications cannot be covered by one common application but rather demands a mix of several cycles.

An increase in global oil consumption, coupled with a peak in oil production, has seen the price of fuel escalate in recent years, and consequently the transport sector must take measures to reduce fuel consumption in vehicles. Similarly, ever-tightening emissions legislation is forcing automotive manufacturers to invest in technology to reduce toxic emissions. In response to these concerns, this project aims to address one of the fundamental issues with the Internal Combustion Engine - approximately one third of the fuel energy supplied to the engine is lost as heat through the exhaust system. The specific aim of this project is to reduce the fuel consumption of a diesel-electric hybrid bus by recovering some of this waste heat and converting it to useful power. This report details how turbocompounding can be applied to the engine, via the inclusion of a turbogenerator, and assesses its waste heat recovery performance.

Looking for fuel efficiency and improvement of the load capacity, new truck designs are targeting chassis weight reduction. As a consequence, the frame can become less stiff, and its higher flexibility can affect the vehicle handling and NVH performance. This paper presents a study of the effects of the frame compliance in regard to the vehicle dynamic behavior.

Gas-operated vehicles powered by natural gas (NG) or other gaseous fuels such as liquefied petroleum gas (LPG), are seen as a possible option for curbing CO₂ emissions, fuel consumption and operating costs of goods and passenger transport. Initiatives have been adopted by various public organizations in Europe and abroad in order to introduce gas-fueled vehicles in their fleets or use retrofit fueling systems in existing ones. In this study a retrofit dual fuel (diesel-gas) fuelling system was investigated as a potential candidate technology for city bus fleets. The system is marketed under the commercial name d-gid. It is a platform developed by the company Ecomotive Solutions for the control and management of a diesel engine fuelled with a mixture of gaseous fuels. In order to assess its environmental and cost effectiveness the system was tested on a Volvo city bus. The tests were performed on an HDV chassis dyno under various driving conditions.