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Journal Article

An Experimental Methodology for Measuring of Aerodynamic Resistances of Heavy Duty Vehicles in the Framework of European CO2 Emissions Monitoring Scheme

2014-04-01
2014-01-0595
Due to the diversity of Heavy Duty Vehicles (HDV), the European CO2 and fuel consumption monitoring methodology for HDVs will be based on a combination of component testing and vehicle simulation. In this context, one of the key input parameters that need to be accurately defined for achieving a representative and accurate fuel consumption simulation is the vehicle's aerodynamic drag. A highly repeatable, accurate and sensitive measurement methodology was needed, in order to capture small differences in the aerodynamic characteristics of different vehicle bodies. A measurement methodology is proposed which is based on constant speed measurements on a test track, the use of torque measurement systems and wind speed measurement. In order to support the development and evaluation of the proposed approach, a series of experiments were conducted on 2 different trucks, a Daimler 40 ton truck with a semi-trailer and a DAF 18 ton rigid truck.
Journal Article

Experimental and Numerical Investigation of the Under Hood Flow with Heat Transfer for a Scaled Tractor-Trailer

2012-04-16
2012-01-0107
Aerodynamic design and thermal management are some of the most important tasks when developing new concepts for the flow around tractor-trailers. Today, both experimental and numerical studies are an integral part of the aerodynamic and thermal design processes. A variety of studies have been conducted how the aerodynamic design reduces the drag coefficient for fuel efficiency as well as for the construction of radiators to provide cooling on tractor-trailers. However, only a few studies cover the combined effect of the aerodynamic and thermal design on the air temperature of the under hood flow [8, 13, 16, 17, 20]. The objective of this study is to analyze the heat transfer through forced convection for a scaled Cab-over-Engine (CoE) tractor-trailer model with under hood flow. Different design concepts are compared to provide low under hood air temperature and efficient cooling of the sub components.
Technical Paper

Enhanced Injector Dead Time Compensation by Current Feedback

2016-04-05
2016-01-0088
The constant motivation for lower fuel consumption and emission levels has always been in the minds of most auto makers. Therefore, it is important to have precise control of the fuel being delivered into the engine. Gasoline Port fuel injection has been a matured system for many years and cars sold in emerging markets still favor such system due to its less system complexity and cost. This paper will explain injection control strategy of today during development, and especially the injector dead-time compensation strategy in detail and how further improvements could still be made. The injector current profile behavior will be discussed, and with the use of minimum hardware electronics, this paper will show the way for a new compensation strategy to be adopted.
Technical Paper

Automotive MOSFETs Operating in the Safe Operating Area

2015-04-14
2015-01-0263
The modern day power MOSFET is constructed using the latest technology in order to minimize the drain source resistance. The latest MOSFET technologies are capable of achieving the same drain to source resistance with a smaller MOSFET die than previous generations which will directly lead to increased thermal resistance and limited energy handling capability. This paper will discuss the Safe Operating Area of power MOSFETs and how to assess new MOSFET technology.
Technical Paper

Smart 24 V Battery Switch for a Reliable Redundant Power Supply in Commercial, Construction, and Agriculture Vehicles (CAV)

2019-10-11
2019-01-5078
For highly automated driving, commercial vehicles require an Electric/Electronic (E/E) architecture, which - in addition to sensor fusion - ensures safety-critical processes such as steering and braking at all times. Among other things, a redundant 24 V supply with corresponding disconnection is required. The battery switch is a key component. Commercial, construction, and agricultural vehicles (CAV) need to operate at the highest possible availability and the lowest possible cost of ownership. This is why automated and autonomous driving has the potential to revolutionize the CAV sector. Driverless machines can be operated around the clock and almost non-stop. Platooning allows automated, interconnected trucks to drive in a convoy and very close to each other. Platooning saves fuel.
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