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Technical Paper

04Road Feel Feedback Design for Vehicle Steer-by-Wire via Electric Power Steering

A new road feel feedback control design of steer-by-wire (SBW) is proposed, which is produce the steering feel of conventional vehicle with equipped electronic power steering (EPS) system, due to SBW system removes mechanical linkages between steering system and front wheels. A dynamic model is established to study the road feel generation and deal with the need of computed rack force of steer system. Based on the analysis of the assisting characteristic and the active damping control strategy of the EPS system, an integrated road feel algorithm is proposed. For rack force is difficult to measure, an estimator is presented to estimate rack force by Kalman filter (KF). The hardware-in-the-loop simulation (HILS) test bench results show that the proposed road feel control design make drivers get road feel information and SBW system can improve the vehicle maneuverability and comfortably.
Technical Paper

10 KWe Dual-Mode Space Nuclear Power System for Military and Scientific Applications

A 10 KWe dual-mode space power system concept has been identified which is based on INEL's Small Externally-fueled Heat Pipe Thermionic Reactor (SEHPTR) concept. This power system will enhance user capabilities by providing reliable electric power and by providing two propulsion systems; electric power for an arc-jet electric propulsion system and direct thrust by heating hydrogen propellant inside the reactor. The low thrust electric thrusters allow efficient station keeping and long-term maneuvering. The direct thrust capability can provide tens of pounds of thrust at a specific impulse of around 730 seconds for maneuvers that must be performed more rapidly. The direct thrust allows the nuclear power system to move a payload from Low Earth Orbit (LEO) to Geosynchronous Earth Orbit (GEO) in less than one month using approximately half the propellant of a cryogenic chemical stage.
Technical Paper

120VAC Power Inverters

Inverters are solid state devices which change DC to 120VAC electricity. They are sufficiently rugged and reliable to make them practical for use on utility vehicles for operating thumpers, tools, lights and induction motor loads. The SCR type rather than the transistor type inverter is generally required for inductive and reactive loads. Static inverters operate from battery input. They provide power without running an engine, but are limited by battery capacity so work best in intermittent load applications. Dynamic inverters operate from alternator input and will handle continuous loads to 7200 watts with truck engine running.
Technical Paper

12V/14V to 36V/42V Automotive System Supply Voltage Change and the New Technologies

This paper shows some aspects of the automotive voltage energy system level shift from 14 to 42 Volts. New features and prospective emissions/fuel economy requirements are creating electrical power needs in future automobiles, which today's conventional system cannot adequately supply at 14 Vdc (nominal, with a 12 Volt battery). It will be necessary to provide electric motors, DC/DC converters, inverters, battery management, and other electronic controls to meet higher voltage requirements. Suppliers must now include 42 Volt components and systems within their product range and make these new components as light, small, and cost efficient as possible. This paper is a compilation of several published works aiming to offer a synthesis to introduce this subject to the Brazilian Automotive Market.
Technical Paper

14/42V - Electrical Power Supply Systems Consequences for Electrical Interconnections and Switches

This paper provides an overview about the consequences of a 14/42 V - Electrical Power Supply System for the Electrical Interconnection and Switching Technology. It presents design guidelines and solutions for connector systems including advanced applications like fuse and relay boxes and gives an overview of those existing connectors already suited for 42 V and even higher voltages. The problem of arcing due to the increased voltage is discussed for the case that mating and unmating under load has to be taken into consideration. Arcing also has a tremendous impact on the design of 42 V proof relays. Therefore, some basic results be presented along with proposals how these problems can be overcome by appropriate designs. Another part of the paper looks at the electrical power supply system itself. Here interconnection techniques for new battery systems are discussed. Finally, the chances for new technologies are highlighted.
Journal Article

2-Drive Motor Control Unit for Electric Power Steering

The electric power steering (EPS) is increasing its number since there are many advantages compared to hydraulic power steering. The EPS saves fuel and eliminates hydraulic fluid. Also, it is more suitable to the cooperation control with the other vehicle components. The EPS is now expanding to the heavier vehicle with the advance in the power electronics. In order to meet customer's needs, such as down-sizing, lower failure rate and lower price, we have developed the new motor control unit (MCU) for the EPS. The motor and the electric control unit (ECU) were integrated for the better installation. We adopted new technologies of redundant 2-drive design for more safe EPS. “2-drive Motor Control technology” which consists of dual winding, two torque sensors and two inverter drive units. In our developed MCU, even if there is a failure in one of the drive unit, the assistance of the EPS can be maintained with the other drive unit.
Technical Paper

270-Vdc/Hybrid 115-Vac Electric Power Generating System Technology Demonstrator

Sundstrand is investigating 270-Vdc/hybrid 115-Vac electrical power generating and distribution systems technology so as to be well prepared to offer such systems for future aircraft applications. The approach taken has been to design, build, and test a representative system that meets or exceeds the tightest of the performance standards as defined by miliary standards. This paper describes a single-channel, 120-kW hybrid system and presents some typical performance data. The dc bus supplies a 30-kVA, 400-Hz, 115-Vac inverter; constant power load banks of up to 150 kW; and a resistive load bank of up to 90 kW. System simulation studies indicated the potential for unstable operation due to the negative impedance of the constant power load in conjunction with the source ripple filter and the load EMI filters. Unstable voltage and current were observed in system testing when the magnitude of the source impedance was not sufficiently below that of the load impedance.
Technical Paper

270-Vdc/Hybrid 115-Vac Electric Power Generating System Technology Demonstrator Evolution to a Dual-Channel, More Electric Aircraft Technology Development Testbed

Sundstrand has been investigating 270-Vdc/hybrid 115-Vac electrical power generating systems (EPGS) technology in preparation for meeting the electrical power generating system (EPGS) requirements for future aircraft (1). Systems such as the one being investigated are likely to be suitable for the More-Electric Aircraft (MEA) concepts presently under industry and military study. The present Sundstrand single-channel testbed is being further expanded to better understand the electrical system performance characteristics and power quality requirements of an MEA in which traditional mechanical subsystems are replaced by those of a “more-electric” nature. This paper presents the most recent Sundstrand 270-Vdc system transient performance data, and describes the modifications being made to the 270-Vdc/hybrid 115-Vac testbed.


This SAE Aerospace Information Report (AIR) describes field-level procedures to determine if 400 Hz electrical connections for external power may have been subjected to excessive wear, which may result in inadequate disengagement forces.

400 Hz Connection Aircraft Electrical Maintenance Procedures

This SAE Aerospace Information Report (AIR) describes field-level procedures to determine if 400 Hz electrical connections for external power may have been subjected to excessive wear, which may result in inadequate disengagement forces.
Journal Article

400Hz High Speed Static Transfer Switch

The objective of this project was to replace electromechanical power line contactors with a Static Transfer Switch (STS) to improve the transfer of electrical power between aircraft generators and decrease required maintenance. The switch requirements include high reliability, lightweight, and high speed (less than 15mS) power transfer. An STS can shorten the bus transfer time to less than the “ride-through” of aircraft electronic loads and therefore have the ability to control and transfer electrical power while maintaining critical mission requirements. The content of this paper and presentation will discuss the initial problem, the research and development approach, design, and initial testing of the STS.
Technical Paper

42 Volt System

The growing electrical power demands on bus electrical systems, such as the electric door operator, power steering, braking, air conditioning, windshield wipers, seat heating, and the need to improve emissions and fuel economy, are making current 12/24-volt electrical systems inadequate. For buses to continue to meet growing customer needs, electrical power must be increased. The industry is currently pursuing a 42-volt system as standard. In the U.S., that number (42 volts) was selected by an industry-wide research consortium led by the Massachusetts Institute of Technology. The switch to a 42-volt system would revolutionize the automotive industry. This would enable more electronic components and new technologies to be added to the vehicle. At the present time, the discussion and implementation of the 42-volt system is largely on luxury vehicles. The potential benefit of the system on heavy duty vehicles has not been fully explored.
Technical Paper

42 Volts - The View from Today

A few years ago, the automobile industry agreed to adopt standards for a new voltage for the production and use of electrical power. The perception was near universal that 14 Volts was at the limits of its capability, and that 42 Volts would be adopted in a rush. The universal perception was wrong. Since then, much of the auto industry has encountered hard financial times. In a totally separate development, parts suppliers introduced innovations at 14 Volts, some of which a few years ago were thought to require 42 Volts. Today, there are 42-Volt cars and trucks for sale, but only at numbers far lower than necessary to begin to achieve economies of scale. But the factor which caused the industry to develop the 42 Volt standard, the growth of electricity use on motor vehicles, continues with no sign of letup. Further, the true technical obstacles to adoption of 42 Volts have been discovered and at least provisionally solved.
Technical Paper

42V PWM Conversion & Control Technologies and E/EDS Architecture

The automotive industry is transitioning from the present 14V electrical system to a 42V system. This voltage evolution is due to the number of new systems (safety, fuel economy and customer convenience) being developed which require increased electrical power that a 14V system cannot deliver. During this transition, it will be necessary to control 14V subsystems in a 42V architecture. This paper presents 42V PWM (Pulse Width Modulation) voltage conversion and control technologies as a solution to control these 14V subsystems.
Technical Paper

42V PowerNet: Providing the Vehicle Electrical Power for the 21st Century

The growth in electrical power demand in future vehicles is expected to significantly exceed the four to five percent annual increases experienced over the last two decades. Continued electrification of traditionally mechanical loads, such as power assist steering, as well as the introduction of new loads, such as AC power points, will overburden the conventional 14V power generation and distribution system. The cost of the electronics to control these new high power systems will add to the challenges associated with the transition. A higher electrical system voltage will be required to meet these ever increasing loads and will help to reduce the control electronics costs. This paper will provide projections of potential future electrical system loads and compare some approaches that could be employed to provide the electrical power to meet the needs.
Technical Paper

42V System for Future Passenger Cars

Fuel economy and emission reduction assume significant importance for automotive research activities and conversion of many mechanical / hydraulic loads to electrical loads helps in realizing this objective. As a result, many electrical power hungry loads are anticipated to be introduced soon in global market with average power requirement exceeding the practical limit of the present automotive electrical system implying the necessity of a suitable higher voltage system. Many OE and component manufacturers have come to a consensus to choose 42V as the system voltage for future passenger cars considering various aspects. This paper highlights the advantages of the high voltage system together with some of the issues associated with the new system.
Technical Paper

48V Mild-Hybrid Architecture Types, Fuels and Power Levels Needed to Achieve 75g CO2/km

48V mild hybrid powertrains are promising technologies for cost-effective compliance with future CO2 emissions standards. Current 48V powertrains with integrated belt starter generators (P0) with downsized engines achieve CO2 emissions of 95 g/km in the NEDC. However, to reach 75 g/km, it may be necessary to combine new 48V powertrain architectures with alternative fuels. Therefore, this paper compares CO2 emissions from different 48V powertrain architectures (P0, P1, P2, P3) with different electric power levels under various driving cycles (NEDC, WLTC, and RTS95). A numerical model of a compact class passenger car with a 48V powertrain was created and experimental fuel consumption maps for engines running on different fuels (gasoline, Diesel, E85, CNG) were used to simulate its CO2 emissions. The simulation results were analysed to determine why specific powertrain combinations were more efficient under certain driving conditions.
Technical Paper

75 Development of an Electronically Controlled Carburetion System to Reduce the Exhaust Emissions of Small IC Engines for Handheld Power Tools

In order to meet the new stringent emission limits for small handheld power tools technologies like methods to improve the scavenging process and after treatment devices are deployed. Additionally, professional machines such as chain saws add particular requirements to avoid mechanical failures. By precise control of the carburetion it is possible to yield the necessary reduction of the emission level yet to maintain the performance of the engine. Thus, the development of an Electronically Controlled Carburetion System to reduce the exhaust emissions of small IC engines for handheld power tools was initiated at the WHZ, Germany. Key requirements of such a system are: low cost, high reliability, low electrical power consumption, high accuracy in metering the fuel demand of the engine. First results are promising. A correlation between exhaust gas temperature and the fuel demand of the engine was confirmed for both, wide open throttle and part load operation.
Technical Paper

A 1,5 KW Electric Power Microcogeneration Unit Suitable for Domestic Applications

The paper discusses the concept, specification and overall performance of a small microcogeneration unit of about 1,5 kW of electric power and about 4,5 kW of thermal power, suitable for domestic applications, designed at Istituto Motori CNR of Italy. This unit has been conceived specifically as a energy conversion system for houses, having in durability, electric and thermal efficiency the most important goals to be achieved. The paper starts by defining the state of art of small power microcogeneration units and then the ratio which leaded to the adoption of a single cylinder internal combustion engine derived from a motorcycle unit, in order to produce the above mentioned electric and thermal power. This is followed by an explanation of the main design characteristics of the system, with a discussion over the modified elements, made to enhance electric efficiency, emissions and durability and reduce, at the same time, cost coming from new design and manufacture.