Fiber Optics for Propulsion Control Systems

1985 ◽  
Vol 107 (4) ◽  
pp. 851-855
Author(s):  
R. J. Baumbick
Keyword(s):  
Full Advantage ◽  
Control Systems ◽  
Fiber Optics ◽  
Optical Fibers ◽  
Optical Sensors ◽  
Optical Waveguides ◽  
Dielectric Waveguides ◽  
Sensors And Actuators ◽  
Propulsion Systems ◽  
Propulsion Control

The term “fiber optics” means the use of dielectric waveguides to transfer information. In aircraft systems with digital controls, fiber optics has advantages over wire systems because of its inherent immunity to electromagnetic noise (EMI) and electromagnetic pulses (EMP). It also offers a weight benefit when metallic conductors are replaced by optical fibers. To take full advantage of the benefits of optical waveguides, passive optical sensors are also being developed to eliminate the need for electrical power to the sensor. Fiber optics may also be used for controlling actuators on engine and airframe. In this application, the optical fibers, connectors, etc., will be subjected to high temperatures and vibrations. This paper discusses the use of fiber optics in aircraft propulsion systems, together with the optical sensors and optically controlled actuators being developed to take full advantage of the benefits which fiber optics offers. The requirements for sensors and actuators in advanced propulsion systems are identified. The benefits of using fiber optics in place of conventional wire systems are discussed as well as the environmental conditions under which the optical components must operate. Work being done under contract to NASA Lewis on optical and optically activated actuators sensors for propulsion control systems is presented.

Adaptive Model Based Control of Aircraft Propulsion Systems: Status and Outlook for Naval Aviation Applications

2006 ◽  
Author(s):  
James W. Fuller ◽  
Aditya Kumar ◽  
Richard C. Millar
Keyword(s):  
Control Systems ◽  
Gas Turbine ◽  
Multiple Goals ◽  
Military Aircraft ◽  
Propulsion Systems ◽  
Model Based Control ◽  
Aircraft Systems ◽  
Model Based ◽  
Propulsion Control ◽  
Aircraft Propulsion

The control of military aircraft propulsion and associated aircraft systems continue to become more demanding, in response to the operational needs of new and existing aircraft and missions. High performance aircraft operate in multiple modes. They are complex and require complex propulsion systems that provide precise and repeatable performance: safely, dependably, and cost effectively. To support these requirements, propulsion control systems must manage multiple effectors based on multiple operating parameters through interactive processes. The scopes of control extends beyond the gas turbine engine to the inlet, exhaust, power and bleed extraction, electrical power systems, thermal & environmental management, fuel systems, starting, accessories, and often propellers, rotors or lift fans. Modern propulsion control systems are increasingly integrated with the aircraft flight controls and the distinction is becoming less & less meaningful. Within the gas turbine, variable geometry and active control of turbo-machinery and auxiliary systems proliferate to relax mechanical design constraints and enable designs with increased thrust to weight ratios, reduced fuel burn and increased durability. Digital controls provide crisp and repeatable responses and improve aircraft reliability and availability, but further enhancements are needed as military aircraft become more capable and versatile (e.g., V-22 and F35). The control system must be aware and appropriately respond to component degradation and damage, optimally managing conflicting constraints and goals. Modern propulsion systems are becoming more profoundly multivariable and include multiple effectors to meet multiple goals. They are multivariable because they are cross-coupled, where each effector can affect multiple goals. In addition, these multiple goals, (e.g., performance, life, operating margin) may be conflicting and need to be traded off, and the best trade off will vary with mission. With predictable and rapid increases in computational capability in Full Authority Digital Electronic Controls, the industry is moving forward to address these needs through model based control, control that manages propulsion and aircraft systems with optimal control responses derived from detailed real time models of component behavior. Since the component characteristics change significantly during a service interval, and yet longer time on wing is necessary, these control systems must sense degradation and damage to multiple components and adapt to it. This paper describes current approaches and NAVAIR plans to develop, mature and deploy this technology, while touching on other potential applications.

scholarly journals Propulsion Control Considerations for V/STOL Aircraft

1972 ◽  
Author(s):  
T. G. Lenox
Keyword(s):  
Control Systems ◽  
Power Management ◽  
Minimum Weight ◽  
Commercial Aircraft ◽  
Propulsion Systems ◽  
Potential Control ◽  
Propulsion Control ◽  
Thrust Control ◽  
Aircraft System ◽  
Maximum Reliability

Potential control requirements of various propulsion systems are currently being studied for V/STOL aircraft applications. This paper identifies the considerations which will affect the design of propulsion control systems for both military and commercial aircraft. Of the requirements common to all configurations, the need for improved thrust control is emphasized as requiring total aircraft system trades to establish an approach which provides the desired power management performance with minimum weight and with maximum reliability and maintainability.

Optical microfibers and nanofibers

Nanophotonics ◽  
2013 ◽  
Vol 2 (5-6) ◽  
pp. 407-428 ◽  
Author(s):  
Xiaoqin Wu ◽  
Limin Tong
Keyword(s):  
Nonlinear Optics ◽  
Fiber Optics ◽  
Optical Fibers ◽  
Optical Sensors ◽  
Near Field ◽  
Field Enhancement ◽  
Atom Optics ◽  
Near Field Optics ◽  
Wavelength Scale ◽  
Sub Wavelength

AbstractAs a combination of fiber optics and nanotechnology, optical microfibers and nanofibers (MNFs) have been emerging as a novel platform for exploring fiber-optic technology on the micro/nanoscale. Typically, MNFs taper drawn from glass optical fibers or bulk glasses show excellent surface smoothness, high homogeneity in diameter and integrity, which bestows these tiny optical fibers with low waveguiding losses and outstanding mechanical properties. Benefitting from their wavelength- or sub-wavelength-scale transverse dimensions, waveguiding MNFs exhibit a number of interesting properties, including tight optical confinement, strong evanescent fields, evident surface field enhancement and large and abnormal waveguide dispersion, which makes them ideal nanowaveguides for coherently manipulating light, and connecting fiber optics with near-field optics, nonlinear optics, plasmonics, quantum optics and optomechanics on the wavelength- or sub-wavelength scale. Based on optical MNFs, a variety of technological applications, ranging from passive micro-couplers and resonators, to active devices such as lasers and optical sensors, have been reported in recent years. This review is intended to provide an up-to-date introduction to the fabrication, characterization and applications of optical MNFs, with emphasis on recent progress in our research group. Starting from a brief introduction of fabrication techniques for physical drawing glass MNFs in Section 2, we summarize MNF optics including waveguiding modes, evanescent coupling, and bending loss of MNFs in Section 3. In Section 4, starting from a “MNF tree” that summarizes the applications of MNFs into 5 categories (waveguide & near field optics, nonlinear optics, plasmonics, quantum & atom optics, optomechanics), we go to details of typical technological applications of MNFs, including optical couplers, interferometers, gratings, resonators, lasers and sensors. Finally in Section 5 we present a brief summary of optical MNFs regarding their current challenges and future opportunities.

High-voltage monitoring by the fiber-optic recirculating measuring system

2020 ◽  
pp. 38-44
Author(s):  
A. V. Polyakov ◽  
M. A. Ksenofontov
Keyword(s):  
Optical Fibers ◽  
High Voltage ◽  
Optical Sensors ◽  
Electromagnetic Interference ◽  
Fiber Optic ◽  
Electric Power Industry ◽  
Measuring System ◽  
Voltage Range ◽  
External Electromagnetic Fields ◽  
Optic Communication

Optical technologies for measuring electrical quantities attract great attention due to their unique properties and significant advantages over other technologies used in high-voltage electric power industry: the use of optical fibers ensures high stability of measuring equipment to electromagnetic interference and galvanic isolation of high-voltage sensors; external electromagnetic fields do not influence the data transmitted from optical sensors via fiber-optic communication lines; problems associated with ground loops are eliminated, there are no side electromagnetic radiation and crosstalk between the channels. The structure and operation principle of a quasi-distributed fiber-optic high-voltage monitoring system is presented. The sensitive element is a combination of a piezo-ceramic tube with an optical fiber wound around it. The device uses reverse transverse piezoelectric effect. The measurement principle is based on recording the change in the recirculation frequency under the applied voltage influence. When the measuring sections are arranged in ascending order of the measured effective voltages relative to the receiving-transmitting unit, a relative resolution of 0,3–0,45 % is achieved for the PZT-5H and 0,8–1,2 % for the PZT-4 in the voltage range 20–150 kV.

scholarly journals Challenges in the Fabrication of Biodegradable and Implantable Optical Fibers for Biomedical Applications

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1972
Author(s):  
Agnieszka Gierej ◽  
Thomas Geernaert ◽  
Sandra Van Vlierberghe ◽  
Peter Dubruel ◽  
Hugo Thienpont ◽  
...  
Keyword(s):  
Systematic Review ◽  
Optical Fibers ◽  
Optical Waveguides ◽  
Biomedical Applications ◽  
State Of The Art ◽  
Chemical Properties ◽  
Biological Tissues ◽  
Biodegradable Materials ◽  
Essential Properties ◽  
Optically Transparent

The limited penetration depth of visible light in biological tissues has encouraged researchers to develop novel implantable light-guiding devices. Optical fibers and waveguides that are made from biocompatible and biodegradable materials offer a straightforward but effective approach to overcome this issue. In the last decade, various optically transparent biomaterials, as well as different fabrication techniques, have been investigated for this purpose, and in view of obtaining fully fledged optical fibers. This article reviews the state-of-the-art in the development of biocompatible and biodegradable optical fibers. Whilst several reviews that focus on the chemical properties of the biomaterials from which these optical waveguides can be made have been published, a systematic review about the actual optical fibers made from these materials and the different fabrication processes is not available yet. This prompted us to investigate the essential properties of these biomaterials, in view of fabricating optical fibers, and in particular to look into the issues related to fabrication techniques, and also to discuss the challenges in the use and operation of these optical fibers. We close our review with a summary and an outline of the applications that may benefit from these novel optical waveguides.

scholarly journals Shaping Beam Profiles Using Plastic Optical Fiber Tapers with Application to Ice Sensors

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2503
Author(s):  
Kostas Amoiropoulos ◽  
Georgia Kioselaki ◽  
Nikolaos Kourkoumelis ◽  
Aris Ikiades
Keyword(s):  
Fiber Optics ◽  
Optical Fibers ◽  
Laser Cooling ◽  
Detection Efficiency ◽  
Numerical Aperture ◽  
Beam Profile ◽  
Hollow Beam ◽  
Enhanced Sensitivity ◽  
Surface Irregularities ◽  
Plastic Optical Fibers

Using either bulk or fiber optics the profile of laser beams can be altered from Gaussian to top-hat or hollow beams allowing enhanced performance in applications like laser cooling, optical trapping, and fiber sensing. Here, we report a method based on multimode Plastic Optical Fibers (POF) long-tapers, to tweak the beam profile from near Gaussian to a hollow beam, by generating surface irregularities on the conical sections of the taper with a heat-and-pull technique. Furthermore, a cutback technique applied on long tapers expanded the output beam profile by more than twice the numerical aperture (NA) of the fiber. The enhanced sensitivity and detection efficiency of the extended profile was tested on a fiber optical ice sensor related to aviation safety.

Optical Waveguides Embedded in PCBs - A Real World Application of 3D Structures Written by TPA

2007 ◽  
Vol 1054 ◽  
Author(s):  
Ruth Houbertz ◽  
Herbert Wolter ◽  
Volker Schmidt ◽  
Ladislav Kuna ◽  
Valentin Satzinger ◽  
...  
Keyword(s):  
Optical Fibers ◽  
Optical Waveguides ◽  
High Speed ◽  
Printed Circuit Boards ◽  
Data Transfer ◽  
Laser Pulses ◽  
Photon Absorption ◽  
Optical Data ◽  
Direct Laser ◽  
High Speed Data

ABSTRACTThe integration of optical interconnects in printed circuit boards (PCB) is a rapidly growing field worldwide due to a continuously increasing need for high-speed data transfer. There are any concepts discussed, among which are the integration of optical fibers or the generation of waveguides by UV lithography, embossing, or direct laser writing. The devices presented so far require many different materials and process steps, but particularly also highly-sophisticated assembly steps in order to couple the optoelectronic elements to the generated waveguides. In order to overcome these restrictions, an innovative approach is presented which allows the embedding of optoelectronic components and the generation of optical waveguides in only one optical material. This material is an inorganic-organic hybrid polymer, in which the waveguides are processed by two-photon absorption (TPA) processes, initiated by ultra-short laser pulses. In particular, due to this integration and the possibility ofin situpositioning the optical waveguides with respect to the optoelectronic components by the TPA process, no complex packaging or assembly is necessary. Thus, the number of necessary processing steps is significantly reduced, which also contributes to the saving of resources such as energy or solvents. The material properties and the underlying processes will be discussed with respect to optical data transfer in PCBs.

scholarly journals Analysis of Curvature in Fiber Optic Cable for Macrobending-Based Slope Sensor

2021 ◽  
Vol 3 (1) ◽  
pp. 45-56
Author(s):  
Imam Mulyanto
Keyword(s):  
Fiber Optics ◽  
Optical Fibers ◽  
Fiber Optic ◽  
Laser Light ◽  
Laser Intensity ◽  
Single Mode ◽  
Power Losses ◽  
Fiber Optic Cable ◽  
Power Meter ◽  
Working Principle

The analysis of fiber optics for macro bending-based slope sensors using SMF-28 single-mode optical fibers has been successfully conducted. Fiber optics were treated to silicon rubber molding and connected with laser light and power meters to measure the intensity of laser power generated. The working principle was carried out using the macrobending phenomenon on single-mode optical fibers. The intensity of laser light in fiber optic cables decreases in the event of indentation or bending of the fiber optic cable. Power losses resulting from the macrobending process can be seen in the result of the information sensitivity of fiber optics to the change of angle given. From the results of the study, the resulting fiber optic sensitivity value is -0.1534o/dBm. The larger the angle given, the lower the laser intensity received by the power meter.

scholarly journals Fabrication of Polyimide Optical Waveguide on Silicon Dioxide Layer Stacked Silicon Substrate

2017 ◽  
Vol 17 (2) ◽  
pp. 36
Author(s):  
Dadin Mahmudin ◽  
Shobih ◽  
Pamungkas Daud ◽  
Yusuf Nur Wijayanto
Keyword(s):  
Silicon Dioxide ◽  
Optical Fibers ◽  
Silicon Substrate ◽  
Optical Waveguides ◽  
Ultra Violet ◽  
Long Distance ◽  
Distance Communication ◽  
Paper Fabrication ◽  
Insertion Losses ◽  
Planar Optical Waveguides

Optical waveguides are important for guiding lightwave from a place to other places. Propagation and insertion losses of the optical waveguides should be considered to be in low values. Recently, optical waveguides with circular structures, which are optical fibers, are used widely for guiding lightwave in long-distance optical communication with very low propagation and insertion losses. Simultaneously, optical waveguides with planar structure are also developed for short distance communication in optical devices. We have reported design and analysis of the planar optical waveguides. In this paper, fabrication of planar optical waveguides using a polyimide material on thin silicon dioxide combined with the silicon substrate is reported. The polyimide material is used for the core of the optical waveguides. The silicon dioxide located on the silicon substrate and the air is used for cladding of the optical waveguides. Fabrication of the optical waveguides such as oxidation, photoresist coating, masking, ultra-violet exposure, and etching was done. The fabricated optical waveguides were characterized physically using a standard microscope and scanning electron microscope (SEM). The fabrication processes and characterization results are reported and discussed in detail.

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