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Four application specific integrated circuits (ASICs) which provide sensing, actuation, and power conversion capabilities for distributed control in a high-temperature (over 200°C) environment are presented. Patented circuit design techniques facilitate fabrication in a conventional, low-cost, 0.5 micron bulk Complimentary Metal Oxide Semiconductor (CMOS) foundry process. The four ASICs are combined with a Digital Signal Processor (DSP) to create a distributed control node. The design and performance over temperature of the control system is discussed. Various applications of the control system are proposed. The authors also discuss various design techniques used to achieve high reliability and long life.

NASA has compiled a set of research goals for five year periods starting 2015, 2020 and 2025 for three classes of future subsonic aircraft, N+1 (2015), N+2 (2020) and N+3 (2025). With the intention of progressively making reductions in noise emissions, greenhouse gas emissions, fuel burn and energy consumption at each of these points to achieve Technology Readiness Levels (TRL's) of between 4 and 6. In the last few years much progress has been made towards achieving these goals through the development of new technologies and designs. This paper assesses how the current More Electric Aircraft (MEA) design concepts are advancing to allow the near term, N+1 goals of reducing 32 dB of noise emissions, 60% of the landing and take-off (LTO) NOx emissions, 55% of cruise emissions and 33% saving of fuel burn and energy consumption, relative to single aisle B737-800, could be met and eventually surpassed.

Electric actuation on aerospace platforms has significant advantages compared to its hydraulic counterparts, particularly in terms of enhanced reliability, reduced maintenance, advanced diagnostic/performance capabilities, and possibly reduced weight and cost. It is thus not surprising that military and commercial aerospace sectors are introducing more electrical actuation architectures. A logical continuation of this trend is the replacement of hydraulic utility actuators in applications with harsh environments such as wide-range ambient temperatures and high vibration, where hydraulic actuation is still dominating. Such environments provide new challenges to the design of electric actuators, particularly considering that performance, weight, volume, and cost should be competitive with the equivalent hydraulic systems.

In this paper, a basic aeronautical electrical network will be modeled in average sense and equipped with a supervisory control strategy for Intelligent Load Power Management (I-LPM) concept implementation. The average modeling process will be first presented, in order to obtain electrical models more suitable for simulations, with respect to traditional switching models, especially in term of simulation time reduction. Specifically, a new average model for SSPC, key components for I-LPM strategy application, will be presented and discussed, where textbook generator and rectifier models will be shortly recalled. Next, the supervisory control strategy will be introduced and briefly discussed, mainly intended as a partial example of energy management strategy where the usage of average models is mandatory, due to required extensive simulation times.

High power levels and high power densities associated with directed energy weapon systems, electronic warfare systems, and high thrust-to-weight aircraft propulsion systems require the development of effective and efficient thermal management solutions. As the objective for many high-power electronic systems is integration onto mobile platforms, strict requirements are also placed on the size, weight, and power draw of the corresponding thermal management system. High peak waste heat loads cannot be efficiently rejected to ambient air in a package integrated onto a mobile platform, leading to the need to store large amounts of energy in a compact, lightweight package. Thermal storage devices must not only be able to store energy rapidly at high power levels but they must also reject energy efficiently, allowing the thermal storage device to recharge for multiple uses.

The Air Force Research Laboratory (AFRL), in cooperation with the University of Dayton Research Institute (UDRI) and Fairchild Controls Corporation, is operating an in-house advanced vapor compression refrigeration cycle system (VCS) test rig known as ToTEMS (Two-Phase Thermal Energy Management System). This test rig is dedicated to the study and development of VCS control and operation in support of the Energy Optimized Aircraft (EOA) initiative and the Integrated Vehicle ENergy Technology (INVENT) program. Previous papers on ToTEMS have discussed the hardware setup and some of the preliminary data collected from the system, as well as the first steps towards developing an optimum-seeking control scheme. A key goal of the ToTEMS program is to reduce the risk associated with operating VCS in the dynamic aircraft environment.

Today's civil airliners integrate electrical power capability properly sized to supply the growing demands of modern aircraft systems, that are more electrical than ever. The conversion of civil aircraft into a military derivative aircraft faces the challenge of rearranging the available generation capability to feed the new power-hungry military systems while at the same time minimizing the impact on certification of the base aircraft for use on civil operations. This challenge is particularly difficult when the new military systems demand high peak power consumption, as in the case of the conversion of a civil airliner into a military Multi-Role Transport Tanker aircraft with high performance multipoint refueling capabilities. In fact the selection of the type of actuation (either electrical or hydraulic) for the refueling systems is heavily conditioned by the excess of either electrical or hydraulic power available in the base aircraft.

In this work we present our recent effort in developing a novel heat exchanger based on endothermic chemical reaction (HEX reactor). The proposed HEX reactor is designed to provide additional heat sink capability for aircraft thermal management systems. Ammonium carbamate (AC) which has a decomposition enthalpy of 1.8 MJ/kg is suspended in propylene glycol and used as the heat exchanger working fluid. The decomposition temperature of AC is pressure dependent (60°C at 1 atmosphere; lower temperatures at lower pressures) and as the heat load on the HEX increases and the glycol temperature reaches AC decomposition temperature, AC decomposes and isothermally absorbs energy from the glycol. The reaction, and therefore the heat transfer rate, is controlled by regulating the pressure within the reactor side of the heat exchanger. The experiment is designed to demonstrate continuous replenishment of AC.

The comparison between a proposed aircraft cabin and cargo heater control system and conventional control schemes is presented together with the key performance figures of the systems. An active AC/DC converter comprising a Phase-Locked Loop (PLL) is proposed to control the energy supplied by the AC Variable Frequency (VF) source to the heater loads instead of controlling the energy by means of a Pulse-Width Modulated (PWM) AC power flow. The proposed system eliminates problems associated with interharmonics generated in the AC VF PWM case - a material advantage. It draws a close to sinusoidal current from the VF source, features a near unity power factor, and operates within the VF range due to the use of PLL.

Modeling and analysis of a reduced order tracking 3-phase Phase-Locked Loop (PLL) based on a combined control principle (error + disturbance) to improve PLL locking performance is presented in this work. The principle is in synthesizing a feedforward control that is added to a Stationary/Floating Frame Transformation PLL or Synchronous (Delta Q) Frame Transformation PLL. The feedforward comprises a frequency-to-voltage converter based on a phase/frequency estimation using an algebraic summation while implementing an inverse feedforward control principle relative to the part of the feedback loop seen after the summing junction. The reduced order tracking PLL is shown to desensitize the system relative to the conventional part PI controller tuning parameters and is operated to lock on either linear or nonlinear load current waveform and for arbitrary frequency/phase profile while maintaining stability by minimizing system dynamics.

Full computational systems are needed at extreme environments (to 300°C) to increase functionality and reduce cost in the ever advancing aerospace, oil and gas, geothermal, and automotive industries. Some suppliers have developed components designed specifically for extreme environments only to find market volumes too small to support the development cost. Low volumes and high cost have limited the choices available to the system designer. Design paradigms for extreme environment suppliers must be altered to address the variety of industry requirements in a cost conscious manner. Designing with extreme environment technology restricts the complexity of a design, not the flexibility. A case study of memory and microcontroller components designed specifically for the extreme environments illustrating development tradeoffs favoring lowering cost and improved flexibility is presented.

In this paper, we study a problem of control system design for small-scale helicopter that has been applied to a robotic helicopter project. The structure of the mathematical models of single-rotor helicopter and the description of its constituent elements are presented. The general mathematical model of a helicopter is a complex multivariable system. This model consists of nonlinear differential equations of the helicopter dynamics, the kinematics and auxiliary equations. The control forces and moments, and also the external disturbances, that affecting on helicopter flight, are in the right side of the dynamic equations. It is necessary to have experimental data for helicopter flight parameters to get adequate auxiliary equations. Those equations have been applied to associate the control forces and moments, to control positions of actuators. In this paper we present the experimental results, estimation algorithms and data-processing.

More electric aircraft (MEA) architectures have increased in complexity leading to a demand for evaluating the dynamic stability of their advanced electrical power systems (EPS). The system interactions found therein are amplified due to the increasingly integrated subsystems and on-demand power requirements of the EPS. Specifically, dynamic electrical loads with high peak-to-average power ratings as well as regenerative power capabilities have created a major challenge in design, control, and integration of the EPS and its components. Therefore, there exists a need to develop a theoretical framework that is feasible and useful for the specification and analysis of the stability of complex, multi-source, multi-load, reconfigurable EPS applicable to modern architectures. This paper will review linear and nonlinear system stability analysis approaches applicable to a scalable representative EPS architecture with a focus on system stability evaluation during large-displacement events.

Functional and energetic issues of control of feeder-airship of MAAT system are considered in the paper. MAAT (Multibody Advanced Airship for Transport) [1,2] is an environmentally friendly system for transportation of passengers and cargos. It consists of cruiser and a few feeders. Cruiser flies in stratosphere at almost fixed altitude. Feeder acts like an elevator, it delivers passengers and cargos from airport to cruiser and in opposite direction. Paper shows, that wide altitude range feeder flies through, strong and dynamic wind loads at various tropospheric and stratospheric altitudes, makes definition of control strategies and energy requirements for control a nontrivial task. That is why this work pays much attention to assessment and mathematical description of feeder flight environment, existing and potential wind profiles, essentially influencing at feeder flight trajectory. Energy efficiency increase is considered in the paper.

Proposes adoption of an industry standard marking protocol to assure the authenticity of high-reliability electronics. The protocol is seen as a key ingredient in the industry's effort to control counterfeit electronic parts escapes. The specifications of the marking protocol have been informed by the experience of the authors, who are currently participating in a DNA marking program mandated by the Defense Logistics Agency. The protocol would set out these criteria for an effective marking program: Simplicity Proven uncopyability Reportability: transparency and ease of oversight Legal validity: empowering of law enforcement Quick ramp-up and seamless implementation Extreme fidelity and absolute character of results - reliability of the mark at a very high level Universal adoption

The operating environment of aircraft causes accumulation and build-up of contamination on both the narrowest passages of the ECS (Environmental Control System) i.e: the heat exchangers. Accumulated contamination may lead to reduction of performance over time, and in some case to failures causing AOG (Aircraft on Ground), customer dissatisfaction and elevated repair costs. Airframers/airlines eschew fixed maintenance cleaning intervals because of the high cost of removing and cleaning these devices preferring instead to rely on on-condition maintenance. In addition, on-wing cleaning is t impractical because of installation constrains. Hence, it is desirable to have a contamination monitoring that could alert the maintenance crew in advance to prepare and minimize disruption when contamination levels exceed acceptable thresholds. Two methods are proposed to achieve this task, The effectiveness of these methods are demonstrated using analytical and computational tools.

This paper describes how the MEE (More Electric Engine) system contributes toward an integrated propulsion control system, with a particular focus on commercial aircraft. Current aircraft systems control the engine rotational speed or pressure ratio to control propulsion, but in future aircraft systems, control of the engine thrust itself will be required. Because controlling engine thrust can be used as an effective method of changing the aircraft speed and/or attitude, various approaches to engine thrust control have been investigated and developed. In this investigation, key technical issues have emerged; one is which is the need for an enhanced engine thrust response for stable control of the aircraft. The other is accurate estimation of engine thrust in flight. Incremental data processing capability is also required due to the need for additional monitoring, evaluation and calculation of engine parameters to ensure safe engine operation.

The designers of heavy-duty off-road vehicles have been facing increasing pressure to reduce the cost and time required for assembly and maintenance. While the requirement to reduce assembly times is mainly an OEM driven objective, the requirement to reduce maintenance times is frequently driven by the customer. The design team is usually faced with the challenge of balancing functional requirements with what are often viewed as wish lists of easy assembly and maintenance, under the pressure of ever shorter development cycles. As a result, vehicle maintainability and ease of assembly are often overlooked early in the design cycle which can lead to less than desired results. This paper explores the design objectives and resultant solutions which were developed in the creation of the power-pack of a heavy-duty off-road vehicle.

The FAA and other Air Navigation Service Providers (ANSPs) plan to share the existing cockpit data radio for NextGen data communication applications. This radio is currently used for supporting airline operations. Sharing this radio, which operates in a relatively open network environment, with mission critical air traffic control communications creates a need to address air-ground security. Most of the data to be shared over air-ground communication is tactical and transient in nature. In addition, secure communication between the controller and the pilot provides situational awareness to all receivers listening on the voice radio channel. In this paper we provide a rationale for securing air-ground communication and explore some of the issues in implementing a secure air-ground communication channel between the controller and the pilot over the shared radio.

The EPS motor will be over-heated if large current lasts for a long time, which will decline the performance of EPS motor and even lead to irreparable damage. So the over-temperature protection control should be conducted in order to protect the components of EPS system, especially the durability of EPS motor. In this paper, the motor temperature was estimated according to the environmental temperature and the current of motor armature, and then the EPS assist current was limited based on the estimated temperature of motor to ensure that the EPS motor had a good working condition. So the over-temperature protection control for motor can be realized without increasing the EPS system components. Finally the control strategy for over-temperature protection was conducted in a vehicle with EPS system and its performance was verified.