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Hybrid Electric Drive (HED) provides the potential to improve military vehicle capabilities beyond the well understood fuel economy benefits. Additional HED benefits for military operations can be realized in the areas of mobility, survivability, lethality, power generation and maintainability. General Dynamics Land Systems (GDLS) continues to demonstrate significant advantages that HED can offer to military vehicle platforms. This presentation will focus on the advanced military capabilities provided by HED utilizing in-hub wheel motors and include a summary of GDLS demonstrator vehicles with integrated HED. Presenter Andrew Silveri, GENERAL DYNAMICS LAND SYST

Abstract This article investigates the fuel savings potential of a series hybrid military truck using a simultaneous battery pack design and powertrain supervisory control optimization algorithm. The design optimization refers to the sizing of the lithium-ion battery pack in the hybrid configuration. The powertrain supervisory control optimization determines the most efficient way to split the power demand between the battery pack and the engine. Despite the available design and control optimization techniques, a generalized mathematical formulation and solution approach for combined design and control optimization is still missing in the literature. This article intends to fill that void by proposing a unified framework to simultaneously optimize both the battery pack size and power split control sequence. This is achieved through a combination of genetic algorithm (GA) and Pontryagin’s minimum principle (PMP) where the design parameters are integrated into the Hamiltonian function.

This standard applies to the interconnection of data terminal equipment and numerical control equipment at the tape reader interface. The data terminal would typically be connected to a remote data source/sink such as a computer. This standard defines: This standard is applicable for the interchange of signals when used in conjunction with electronic equipment, each interchange circuit of which has a single return (signal ground) that can be interconnected at the interface point. Figure 1.1, typical installation, shows how this standard should be applied to a typical tape reader interface of numerical control equipment.

This document is intended to explain, in detail, the rationale behind the features and functions of the AS4074, Linear, Token-passing, Bus (LTPB). The discussions also address the considerations which a system designer should take into account when designing a system using this bus. Other information can be found in these related documents: AIR4271 - Handbook of System Data Communication AS4290 - Validation Test Plan for AS4074

This document is intended to explain, in detail, the rationale behind the features and functions of the AS4074, Linear, Token-passing, Bus (LTPB). The discussions also address the considerations which a system designer should take into account when designing a system using this bus. Other information can be found in these related documents:

This section defines the scope of the document, provides a brief history of the Pi-Bus, discusses key features of the Pi-Bus, and provides an overview of the operation of the Pi-Bus. This document is a handbook intended to accompany AS4710 Pi-Bus standard. The purpose of this document is to provide information to aid users of the Pi-Bus, whether they be implementors of Pi-Bus controllers, architects of systems considering using the Pi-Bus, or programmers who must develop applications in a system which uses the Pi-Bus as the backplane communications bus. This document also provides rationale for many of the Pi-Bus requirements as defined in AS4710 and a discussion of potential enhancements that are being considered for the Pi-Bus.

This section defines the scope of the document, provides a brief history of the Pi-Bus, discusses key features of the Pi-Bus, and provides an overview of the operation of the Pi-Bus. This document is a handbook intended to accompany AS4710 Pi-Bus standard. The purpose of this document is to provide information to aid users of the Pi-Bus, whether they be implementors of Pi-Bus controllers, architects of systems considering using the Pi-Bus, or programmers who must develop applications in a system which uses the Pi-Bus as the backplane communications bus. This document also provides rationale for many of the Pi-Bus requirements as defined in AS4710 and a discussion of potential enhancements that are being considered for the Pi-Bus.

The continual reduction of diesel engine heavy-duty nitrous oxides and particulate matter emissions due to Environmental Protection Agency (EPA) regulations has resulted in significant changes to engine hardware since 1998. Such changes have included use of cooled exhaust gas recirculation, clean gas induction, oxidation catalysts, variable geometry turbochargers, lean nitrous oxide traps, urea selective catalytic reduction, passive and catalyzed particulate matter filters, and engine design changes to reduce oil consumption while allowing use of low sulfur diesel fuel (DF-2) and maintaining oil change intervals and subsystem durability levels of previous model years. The net result from a propulsion system perspective is increased heat rejection, additional induction and exhaust system volume, increased system weight, and less tolerance to military fuels and lubricants.

Modern heavy duty Commercial Off The Shelf (COTS) diesel engines represent the state of the art in engine performance and design features, control architecture, and the use of light weight high strength materials. These engines, with appropriate adaptation for operation on military fuels, make excellent choices for defense applications. This paper reviews the selection and modification of a COTS engine suitable for potential defense applications. Considerations for robust operation of the engine on JP8, engine system modifications appropriate for military vehicle emission requirements, reduction of engine system heat rejection, and optimization of engine efficiency will be discussed using example data from converting a 2011 model year COTS engine for defense applications. This work was funded by the Tank Automotive Research, Development and Engineering Center (TARDEC) from Broad Agency Announcement (BAA) Topic 15, awarded in 2009.

Ride control of military vehicles is challenging due to varied terrain and mission requirements such as operating weight. Achieving top speeds on rough terrain is typically considered a key performance parameter, which is always constrained by ride discomfort. Many military vehicles using passive suspensions suffer with compromised performance due to single tuning solution. To further stretch the performance domain to achieving higher speeds on rough roads, semi-active suspensions may offer a wide range of damping possibilities under varying conditions. In this paper, various semi-active control strategies are examined, and improvements have been made, particularly, to the acceleration-driven damper (ADD) strategy to make the approach more robust for varying operating conditions. A seven degrees of freedom ride model and a quarter-car model were developed that were excited by a random road process input modeled using an auto-regressive time series model.

In this paper we present a set of integrated circuits specifically designed for high temperature power applications such as isolated power transistor drivers and high efficiency power supplies. The XTR26010 is the key circuit for the isolated power gate drive application. The XTR26010 circuit has been designed with a high focus in offering a robust, reliable and efficient solution for driving a large variety of high-temperature, high-voltage, and high-efficiency power transistors (SiC, GaN, Si) existing in the market. The XTR40010 is used for isolated data communication between a microcontroller or a PWM controller and the power driver (XTR26010). The isolated power transistor driver features a dual turn-on channel, a turn-off channel and a Miller Clamp channel with more than 3A peak current drive strength for each channel. The dV/dt immunity between XTR26010 and XTR40010 exceeds 50kV/μs.

It is of considerable interest to developers of military vehicles, in early phases of the concept design process as well as in Analysis of Alternatives (AoA) phase, to quickly predict occupant injury risk due to under-body blast loading. The most common occupant injuries in these extremely short duration events arise out of the very high vertical acceleration of vehicle due to its close proximity to hot high pressure gases from the blast. In a prior study [16], an extensive parametric study was conducted in a systematic manner so as to create look-up tables or automated software tools that decision-makers can use to quickly estimate the different injury responses for both stroking and non-stroking seat systems in terms of a suitable blast load parameter. The primary objective of this paper is to quantitatively evaluate the accuracy of using such a tool in lieu of building a detailed model for simulation and occupant injury assessment.

The incorporation of hydrogen fuel cells into heavy duty tactical mobility vehicles can bring about great opportunities in reducing the pollutant emissions of this kind of platforms (GVW > 30,000 kg). Furthermore the transportation of fuel to operational areas has become a key aspect for any deployment therefore optimal use of this resource is of paramount importance. Finally, it is also quite common for such platforms to serve additional purposes, besides freight delivery, such as powering external equipment (i.e. field hospitals or mobile artillery pieces). This work will describe the intelligent energy management system for a PEM Fuel Cell-Battery-Ultracapacitor Hybrid 8×8 heavy truck of the aforementioned weight class which also contemplates an internal electric/traction power generation unit. It will describe how the system optimizes the use of battery and hydrogen fuel energy while keeping system efficiency and performance at a maximum.

In a competitive engineering business world, there is a constant demand to meet stringent emissions and on board diagnostic (OBD) regulations in a cost-effective manner. Engineers are tasked with the responsibility to innovate and design solutions around cost-cutting measures that involve reducing bill of material costs on the printed circuit board (PCB). Varied features in commercial application specific integrated circuits (ASIC) devices makes it more challenging to create consistent engineering design methods to provide critical inputs for controls and diagnostic strategies. In addition, continuous evolution of the emissions and OBD regulations in the different markets make it challenging for ASIC design manufacturers to evolve their hardware designs quickly. One such input is soak time. Soak time is typically defined as the amount of time the engine has been turned off. Emission controls and OBD algorithms use soak time to enable cold and hot start processing strategies.

Investigating the impact of Gasoline fuel on diesel engine performance and emission is very important for military heavy- duty combat vehicles. Gasoline has great potential as alternative fuel due to rapid depletion of petroleum reserves and stringent emission legislations, under multi fuel strategy program for military heavy- duty combat vehicle. There is a known torque, horsepower and fuel economy penalty associated with the operation of a diesel engine with Gasoline fuel. On the other hand, experimental studies have suggested that Gasoline fuel has the potential for lowering exhaust emissions, especially NOx, CO, CO2, HC and particulate matter as compared to diesel fuel. Recent emission legislations also restrict the total number of nano particles emitted in addition to particulate matter, which has adverse health impact.