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Journal Article

Wavelet Analysis for Frequency Disturbance Characterization in an Electric Vehicle

Reduction of CO2 emission is a mandatory objective for every actor in the field of automotive transport, and electric vehicles (EV's) are increasingly becoming an effective option for both OEMs and customers. However, components development and vehicle integration for EV's present new challenges that must be faced and new issues which need to be solved. In particular electric motor control systems are developed to achieve the same comfort conditions as in conventional vehicles. IDIADA developed a prototype electric commercial vehicle in which both the motor and driveline were integrated. The electric motor output shaft delivers the torque to the transmission under a certain level of load variation and with torque irregularities that must be smoothed out in the transmission components. This paper studies the results of the testing of the prototype vehicle carried out to improve the overall NVH behavior of the powertrain.
Technical Paper

Wavelet-based Fouling Diagnosis of the Heat Exchanger in the Aircraft Environmental Control System

The Environmental Control System (ECS) of an aircraft provides thermal and pressure control of the engine bleed air for comfort of the crew members and passengers onboard. For safe and reliable operation of the ECS under complex operating environments, it is critical to detect and diagnose performance degradations in the system during early phases of fault evolution. One of the critical components of the ECS is the heat exchanger, which ensures proper cooling of the engine bleed air. This paper presents a wavelet-based fouling diagnosis approach for the heat exchanger.

Ways of Dealing with Power Regeneration onto an Aircraft Electrical Power System Bus

This SAE Aerospace Information Report (AIR) considers the issue of power regeneration into the EPS of an aircraft. A series of options for dealing with this regenerative power are considered and arranged in categories. Advantages and disadvantages of each solution, including the existing solution, are included. Validated simulation results from representative Electrical Power systems are presented in order to demonstrate how some of the solutions may operate in practice and how power quality can be maintained during regeneration. The impact on changes to the electrical generation system are also highlighted in this AIR, as these changes may have an impact on the solution deployed and the wider impact on the design of engines and auxiliaries. This AIR reviews concepts and excludes detailed discussions on power system design. These concepts relate to the More Electric Aircraft, cover both AC and DC systems and can be applied to both normal operating conditions or as fault mitigation.
Technical Paper

Weight and Dimensional Parameters of a Power Drive for Electrical Vehicle

The electric drive with the synchronous electrical machine of independent excitation differs by high specific parameters, adaptability to manufacture, simplicity of a design, and reliability. These properties of the electric drive allow using it in heavy conditions of operation. In particular, it can be recommended to use in electrical vehicles. The electric motor for this electric drive can be executed with two separate stator windings. Therefore, there are additional benefits connected to an opportunity of change of geometry of an iron stator stamp of the given type motor. In this report, the principle of operation of the electric drive with control system is considered. The different variants of a stator design of the electrical machine are discussed. The stator design allows improve of the mass and weight parameters of the electric machine. For the offered stator designs, the comparison of specific parameters (relationship of the nominal torque to load current) is carried out.
Technical Paper

What's Next in Commercial Aircraft Environmental Control Systems?

Before considering the future of aircraft environmental control systems (ECS's), a review of the relatively short history of this field would be valuable in understanding the present situation. Therefore, this paper notes many of the significant developments in commercial aircraft air-cycle refrigeration and in cabin environmental control. The evolution leading to the great variety of air-cycle systems now in production, or under development, is discussed along with a generic comparison of the merits of the various system types and some reasons for their selection. Constraints on air conditioning system development imposed by the airline operators, aircraft manufacturers, and regulatory agencies are touched upon as significant to charting the future direction of air conditioning system design. Finally, several directions that could be taken in future design are briefly commented upon.
Technical Paper

Wheel Lock Control Braking System

Automobile and truck manufacturers have given increasing attention to electronic wheel lock control brake systems during the last few years. These systems prevent continuous wheel lock-up during maximum braking stops, thus aiding the driver in retaining lateral stability and generally improving stopping distances. This presentation discusses a system for preventing continuous rear wheel lock-up of an automobile during maximum braking stops. Included is a description of the control system components, tire and road characteristics, brake and vehicle dynamics, and an analysis leading to the requirements for optimum control.
Technical Paper

Who Needs Avionics Performance Minimums - The Government or You?

A lengthy effort to develop the minimum operational requirements of avionics systems needed for participation in the air traffic control system has not yet yielded standards or a means of administration acceptable to all segments of aviation. A new, more palatable approach by which users of the airspace can provide certain minimum operational characteristics in their airborne electronic systems shows promise. In order to make it work, FAA must clearly describe its electronic systems, how they work, and what their limitations are, so that willing participants may find out what they need to do in order to be right. Based on these system standards, minimum operational characteristics of airborne avionics can be developed and implemented. These may then meet with the approval of most of those affected, since the requirements will merely represent their own self-interest.
Technical Paper

Why Companies Use Air Freight — A Basic Consideration in Air Freight Systems Planning and Traffic Forecasting

Use of air freight depends not on the commodity or industry, as such, but on the combinations of characteristics that enable company to benefit from air shipment in any particular situation. Air freight handling and control systems should augment, not decrease, these benefits. Future air freight traffic must be forecast in terms of the different benefits sought in shipping by air. Research is required to determine the relative importance of different benefits in future traffic generation. Research areas are defined and cooperative research efforts urged.
Technical Paper

Wind Tunnel and Flight Development of Spoilers for General Aviation Aircraft

Wind tunnel tests have been carried out to develop a spoiler lateral control system for use with the GA(W)-1 airfoil with a 30% Fowler flap. Tests show that unfavorable aerodynamic interactions can occur between spoiler and flap for large flap deflections. Providing venting of lower surface air through the spoiler opening substantially improves performance. Results of tests with a number of spoiler and cavity shapes are presented and discussed. Applications of two-dimensional wind tunnel results to the design of satisfactory manual lateral control systems are discussed.

Wire Fed Plasma Arc Directed Energy Deposition Additive Manufacturing Process

This specification establishes process controls for the repeatable production of preforms by Wire Fed Plasma Arc Directed Energy Deposition (PA-DED). It is intended to be used for aerospace parts manufactured using Additive Manufacturing (AM) metal alloys, but usage is not limited to such applications.

Wireless Power Transfer for Light-Duty Plug-In/ Electric Vehicles and Alignment Methodology

SAE TIR J2954 establishes an industry-wide specification guideline that defines acceptable criteria for interoperability, electromagnetic compatibility, minimum performance, safety and testing for wireless charging of light duty electric and plug-in electric vehicles. The current version addresses unidirectional charging, from grid to vehicle, but bidirectional energy transfer may be evaluated for a future standard. The specification defines various charging levels that are based on the levels defined for SAE J1772 conductive AC charge levels 1, 2 and 3, with some variations. A standard for wireless power transfer (WPT) based on these charge levels will enable selection of a charging rate based on vehicle requirements, thus allowing for better vehicle packaging, and ease of customer use. The specification supports home (private) charging and public wireless charging.

Wireless Power Transfer for Light-Duty Plug-In/Electric Vehicles and Alignment Methodology

The SAE Recommended Practice J2954 establishes an industry-wide specification that defines acceptable criteria for interoperability, electromagnetic compatibility, EMF, minimum performance, safety and testing for wireless charging of light duty electric and plug-in electric vehicles. The current version addresses unidirectional charging, from grid to vehicle, but bidirectional energy transfer may be evaluated for a future standard. The specification defines various charging levels that are based on the levels defined for SAE J1772 conductive AC charge levels 1, 2, and 3 with some variations. A standard for wireless power transfer (WPT) based on these charge levels will enable selection of a charging rate based on vehicle requirements, thus allowing for better vehicle packaging, and ease of customer use. The specification supports home (private) charging and public wireless charging.
Technical Paper

Working Fluid De-freezing in Radiator on Base of LHP

Selection of working fluid is one of the main criterions for designing of heat pipes thermal control systems (TCS) for space application. In this paper we will describe how we solved the task of development of the TCS with working fluid of high thermal physical properties. In 2004-2006 we developed the Engineering model of Deployable Radiator based on Loop Heat Pipe by CAST purchase order. It was developed for qualification tests. Ammonia application as LHP working fluid is stipulated by its high thermal physical properties. However Ammonia freezing temperature is of minus 77ºC. Such fact impedes Ammonia application when operation temperatures of LHP Radiator are lower than this value, for example, It takes several tens of hours to orbit a spacecraft and prepare it for work (at that moment the spacecraft is out of power supply) and the working fluid can be frozen in a condenser-radiator when the spacecraft being in the shadow over a long period of time.
Technical Paper

X-29A Subsystems Integration - An Example for Future Aircraft

The X-29A is the first X-series experimental aircraft developed in the United States since the mid-sixties. The X-29A is a technology demonstrator aircraft that integrates several different-technologies into one airframe. Among the technologies demonstrated are the aeroservoelastically tailored composite forward swept wings, close coupled canards, discrete variable camber wing, triplex digital flight control system with analog backup, thin supercritical wing, three surface pitch control, large negative static margin and the integration of these technologies into the X-29 airframe. This paper deals with the issue of technology integration of five of the X-29A subsystems and the early design decision to use existing aircraft, components whenever and wherever possible. The subsystems described are the X-29 aircraft Hydraulics System, the Electrical Power System, the Emergency Power System, the Aircraft Mounted Accessory Drive and the Environmental Control System.
Technical Paper

Xerox's Distributed Real Time Control System

XEROX has developed and implemented a network architecture for a real time control system which has expansion flexibility, high reliability, noise immunity, and low cost. This two level multiplex system with a single wire system bus at one level for distributed processors connected to local serial buses at the second level for remote functions and loads is described. The XEROX Microelectronics Center has developed a set of custom VLSI chips to implement the multiplexing architecture. Control software was developed using both assemblers and high level language tools. The software and chip set have been designed, built and integrated into XEROX'S latest generation of products.
Technical Paper

Xtreme Make-Over In 24 Hours

Our conference chairman told me that this special technical section was structured to provide “some words of wisdom from the old guys” or something to that effect. I know I can meet most of his requirements. I am a pensioner and an oak tree. However, “words of wisdom” maybe a challenge. Solving noise problems, setting acoustical performance targets and guidelines, and developing noise control systems for new and carry-over vehicles can be very challenging and time consuming particularly in today's culture. In the 1970's and 80's, and 90's we had the same challenges. Our customers demanded and appreciated a quiet vehicle. They want to talk to each other without shouting or to enjoy a favorite music selection regardless of weather, road conditions, or vehicle speed. The use of ear plugs or cotton is not acceptable! Noise Gremlins (Figure 1) can ruin a good day!
Technical Paper

Yaw Rate Sensor for Vehicle Dynamics Control System

From the beginning of 1995 on, RB will start the production of the Vehicle Dynamics Control System. A key part of this system is the Yaw Rate Sensor described in this paper. The basic requirements for this sensor for automotive applications are: mass producibility, low cost, resistance against environmental influences (such as temperature, vibrations, EMI), stability of all characteristics over life time, high reliability and designed-in safety. Bosch developed a sensor on the basis of the “Vibrating Cylinder”. The sensor will be introduced into mass production in beginning of 1995.
Technical Paper

Zinc-Chloride Electric EngineTM Unit for Four-Passenger Electric Vehicle

Energy Development Associates, a division of Gulf+Western Industries, Inc., has undertaken the design and fabrication of a four-passenger electric car incorporating state-of-the art zinc-chloride battery technology. The purpose of the project is to demonstrate the viability of the zinc-chloride energy storage system as a practical alternative to cars powered by internal combustion engines. Significant among the project goals to be achieved is the attainment of a vehicle range three to four times that of current lead-acid battery-powered vehicles on a single battery charge. Progress to date on the project is discussed. It includes the design, specification, and fabrication of the battery, vehicle and its components, motor control system, and battery control microprocessor.