Browse Topic: Flight control systems

Items (835)
The development of low-altitude economy driven by aircraft has garnered significant attention from both academia and industry. The hexacopter unmanned aerial vehicle (UAV) is an important component of low-altitude aircraft. Although it has not been as widely used as the quadcopter UAV, the greater delivery capacity and enhanced fault tolerance sustain its promising development prospects. However, the trajectory tracking control, a fundamental task of hexacopter UAV, remains challenging if the control algorithm is required to work on the dynamics level with theoretical performance guarantees, since its position control has to be realized by its attitude control. This study proposes a novel trajectory tracking control with prescribed performance for the hexacopter UAV that works on the dynamic model. The proposed approach is established by a dual-loop constraint-following control with the state-transformation technique, where equality and inequality constraints are used to describe the
Wang, NingningLi, XiangYin, Hui
This document (AIR6005) provides the framework for the specifications of a WDM OBN within the SAE AS5659 WDM LAN Specification document family, in particular, the Transparent Optical Backbone Network Specification. This framework includes potential requirements, technical background, investigation and context to support the writing of SAE’s WDM LAN specifications documents. The SAE’s AS6005 WDM OBN document describes a transparent optical network which contains optical components and optical interfaces to perform optical transport, optical add/drop, optical amplification, optical routing, and optical switching functions. The conforming optical signal interfaces for the data plane of the WDM OBN are defined. The conforming signal interfaces for the control and management planes of this network are also defined. The control and management plane signals may be either electrical or optical. If successful, a WDM LAN standard is anticipated to include multiple variants that may get created
AS-3 Fiber Optics and Applied Photonics Committee
Paris, June 18, 1914: Crowds gathered at the “Concours de la Sécurité en Aéroplane” to witness 21-year-old Lawrence Sperry demonstrate his newly invented gyroscopic stabilizer. With his hands in the air, the device flew his Curtiss C-2 flying boat. Only a decade after the Wright brothers’ initial flight, the first n “autopilot” made its public debut. As impressive as this public demonstration was, it was merely a humble, although spectacular moment of foreshadowing. Even today—110 years later—the process of automating aspects of flight has not yet fully concluded, leading to deteriorating insight into the automatic behavior of aircraft systems, and even the waning of human instincts and intuition. Controlling Aircraft—From Humans to Autonomous Systems: Rise of the Machines covers the distancing of humans from their flying machines through more than a century-long process of “assisting” systems introduction, the positive and negative consequences of this process, and mitigation
David, Aharon
The intent of this AIR is twofold: (1) to present descriptive summary of aircraft nosewheel steering and centering systems, and (2) to provide a discussion of problems encountered and “lessons learned” by various airplane manufacturers and users. This document covers both military aircraft (land-based and ship-based) and commercial aircraft. It is intended that the document be continually updated as new aircraft and/or new “lessons learned” become available
A-5B Gears, Struts and Couplings Committee
This SAE Aerospace Information Report (AIR) provides the hydraulic and flight-control system designer with the various design options and techniques that are currently available to enhance the survivability of military aircraft. The AIR addresses the following major topics: a Design concepts and architecture (see 3.2, 3.5, and 3.6) b Design implementation (see 3.3, 3.6, and 3.7) c Means to control external leakage (see 3.4) d Component design (see 3.8
A-6A2 Military Aircraft Committee
This Technical Governance is part of the SAE UCS Architecture Library and is primarily concerned with the UCS Architecture Model (AS6518) starting at Revision A and its user extensions. Users of the Model may extend it in accordance with AS6513 to meet the needs of their UCS Products. UCS Products include software components, software configurations and systems that provide or consume UCS services. For further information, refer to AS6513 Revision A or later. Technical Governance is part of the UCS Architecture Framework. This framework governs the UCS views expressed as Packages and Diagrams in the UCS Architecture Model
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This aerospace recommended practice provides a framework and suggested procedures or values for requirements for the design, performance, and test of hydraulically powered servoactuators for use in aircraft flight control systems. The original version of this document was intended for military usage: consequently, the requirements still often reflect such use. However, the basic requirements of this ARP may and should be applicable to commercial usage as well, provided that appropriate considerations are given for the applicable FAR/JAR 25 regulations, hydraulic fluids, and environmental conditions
A-6B1 Hydraulic Servo Actuation Committee
In autonomous technology, uncrewed aircraft systems have already become the preferred platform for the research and development of flight control systems. Although they are subjected to following and satisfying complicated scenarios of control stations, this high dependency on a specific control framework limits them in their application process and reduces the flight self-organizing network. In this article, we present a developed multilayer control system protocol with the additional supportive manned aircraft layer (Tender). The novelty of the introduced model is that uncrewed aircraft systems are monitored and navigated by the tender, and then based on the suggested scheme, data flows are controlled and transferred across the network by the developed cloud–robotics approach in the ground station layer. Therefore, it has been tried to design a semi-autonomous control network to gather data that combines human observation and the automotive nature of uncrewed aircraft systems. To
Millar, Richard C.Laliberté, JeremyMahmoodi, ArminHashemi, LeilaMeyer, Robert Walter
Over the past few decades, aircraft automation has progressively increased. Advances in digital computing during the 1980s eliminated the need for onboard flight engineers. Avionics systems, exemplified by FADEC for engine control and Fly-By-Wire, handle lower-level functions, reducing human error. This shift allows pilots to focus on higher-level tasks like navigation and decision-making, enhancing overall safety. Full automation and autonomous flight operations are a logical continuation of this trend. Thanks to aerospace pioneers, most functions for full autonomy are achievable with legacy technologies. Machine learning (ML), especially neural networks (NNs), will enable what Daedalean terms Situational Intelligence: the ability to understand and make sense of the current environment and situation but also anticipate and react to a future situation, including a future problem. By automating tasks traditionally limited to human pilots - like detecting airborne traffic and identifying
Electrical Vertical Takeoff and Landing (eVTOL) vehicles hold great promises for revolutionizing urban mobility. Their emergences as a transformative transportation technology has led multiple Original Equipment Manufacturers (OEM) competing for market share, with important variety of technical solutions, all necessitating to demonstrate the compliance to safety requirements and regulations. Model Based Safety Analysis (MBSA), newly introduced in ARP4761A and based on compositional and modular representation of failure propagation paths within one system, provides a unique opportunity to increase efficiency by maximizing the possible reuse of safety analyses elements across multiple architectures (“product line” philosophy). Generic library of safety models for elements of variant architectures can be efficiently constructed using MBSA techniques that can then support safety analyses on variant architectures or architectures trade-off. This approach can facilitate a safety process that
Adeline, RomainWang, JiaHua, Angelina
Advanced flight control system, aviation battery and motor technologies are driving the rapid development of eVTOL to offer possibilities for Urban Air Mobility. The safety and airworthiness of eVTOL aircraft and systems are the critical issues to be considered in eVTOL design process. Regarding to the flight control system, its complexity of design and interfaces with other airborne systems require detailed safety assessment through the development process. Based on SAE ARP4754A, a forward architecture design process with comprehensive safety assessment is introduced to achieve complete safety and hazard analysis. The new features of flight control system for eVTOL are described to start function capture and architecture design. Model-based system engineering method is applied to establish the functional architecture in a traceable way. SFHA and STPA methods are applied in a complementary way to identify the potential safety risk caused by failure and unsafe control action. PSSA with
Ning, ChengweiZhang, HaoWeng, HaiminMa, Ran
The presence of a slung-load during the flight of a quadrotor generates swing effects that can greatly influence the dynamics of the quadrotor. These effects have the potential to threaten the stability of the system’s attitude. This study presents a disturbance compensation strategy that is designed based on the utilization of an adaptive harmonic extended state observer (AHESO) in order to solve this problem and achieve precise attitude control. To derive the aforementioned algorithm, a comprehensive mathematical model for the quadrotor-slung-load system is built. The periodic features of disturbance are derived by considering the movement of the slung-load. Subsequently, by taking the periodic features of the disturbances into account, the AHESO for accurate disturbance estimation is designed. In this observer, an online frequency estimator for the harmonic disturbances is introduced. Lyapunov theory is introduced to examine the stability of the AHESO. In addition, backstepping
He, TongfuSong, GuangyiSong, DaleiLv, JiahuiZhou, Liqin
Increasing the degree of individuality of the autopilot and adapting it to the habits of drivers with different driving styles will help to increase occupant acceptance of the autopilot function. Inspired by the Twin Delayed Deep Deterministic policy gradient algorithm(TD3) algorithm to increase action spontaneity, this paper proposes a Soft Actor-Critic(SAC) based personalized following control strategy to increase the degree of strategy personalization through driver data. In order to obtain real driver data, this paper collected driving data based on driver-in-the-loop experiments conducted on a simulated driving platform, and selected data from three drivers with distinctive driving characteristics for model training. A continuous action space model was developed by vehicle following kinematics. A temporal Gate Recurrent Unit (GRU) based reference model is trained to receive temporal state signals and output acceleration actions according to the current state. In this paper, we
Wu, MingzhiYu, QinHu, YimingLiu, Xuegao
This work introduces a practical approach to external synchronization for flight control computers (FCCs) deployed in a decentralized fashion. The internal synchronization among the FCCs in distributed flight control systems needs to be extended for specific applications, necessitating an urgent need for an external synchronization mechanism. For instance, when the air data and attitude reference system (ADAHRS) and the flight control computer (FCC) are not synchronized, a dead time or time offset occurs between the time the ADAHRS transmits data and the time the FCC begins executing its control functions, which can impair flight control system performance or even cause system instability, particularly for the system with incremental control approaches, such as incremental nonlinear dynamic inversion (INDI). Therefore, an external synchronization technique that does not rely on establishing a global view of time that is accurately synchronized with an external reference device has been
Khozin, MokhamadHolzapfel, Florian
Artificial intelligence (AI) has become prevalent in many fields in the modern world, ranging from vacuum cleaners to lawn mowers and commercial automobiles. These capabilities are continuing to evolve and become a part of more products and systems every day, with numerous potential benefits to humans. AI is of particular interest in autonomous vehicles (AVs), where the benefits include reduced cognitive workload, increased efficiency, and improved safety for human operators. Numerous investments from academia and industry have been made recently with the intent of improving the enabling technologies for AVs. Google and Tesla are two of the more well-known examples in industry, with Google developing a self-driving car and Tesla providing its Full Self-Driving (FSD) autopilot system. Ford and BMW are also working on their own AVs
This Aerospace Standard covers all automatic pressure altitude code generating equipment manufactured under this standard and complying with the requirements specified herein up to the maximum range of pressure altitude as indicated on the equipment nameplate. In those cases where the code generating equipment forms part of an aircraft system, such as a pressure altimeter, an air data computer or an ATC Transponder, this standard applies only to the code generating equipment as defined in paragraph 1.2
A-4ADWG Air Data Subcommittee
This AS covers subsonic and supersonic Mach meter instruments which, when connected to sources of static (Ps), and total (Pt), or impact (Pt-Ps), pressure provide indication of Mach number. These instruments are known as Type A. This AS also covers servo-operated repeater or digital display instruments which indicate Mach number when connected to the appropriate electrical output of a Mach transducer of Air Data Computer. These instruments are known as Type B
A-4ADWG Air Data Subcommittee
This AS defines instruments which use inputs of static and pitot pressure equal to those which are utilized to establish the pressure altitude and speed of that aircraft. These pressures are applied to the instrument ports to provide means for generation of an aural warning whenever the aircraft reaches or exceeds the maximum operating limit speed. This Over Speed Warning Instrument function may be incorporated as part of an Air Data Computer, or an Air Speed Indicator, or an Air Speed/Mach Number Indicator, or other instruments. In those cases where the Over Speed Warning Instrument is part of another instrument, the standards contained herein apply only to the Over Speed Warning Instrument function. Each aircraft type and model has a defined maximum operating limit speed curve or curves which are a part of the airframe manufacturer's type certification approval data; this limit speed data shall be available from the subject airframe manufacturer as published in the operating manual
A-4ADWG Air Data Subcommittee
This document provides recommended practices regarding how System Theoretic Process Analysis (STPA) may be applied to safety-critical systems in any industry
Functional Safety Committee
This SAE Aerospace Information Report (AIR) has been compiled to provide information on hydraulic systems fitted to the following categories of military vehicles. Attack Airplanes Fighter Airplanes Bombers Anti-Sub, Fixed Wing Airplanes Transport Airplanes Helicopters Boats
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This Aerospace Information Report (AIR) provides information on systems integration rigs, commonly referred to as “Iron Birds” for aerospace applications. a It includes background historical information including descriptions of Iron Birds produced to date, important component elements and selection rationale, hydraulic system design and operational modes and illustrates the design approaches to be considered. b It provides illustrations of the various systems that should be considered for Iron Bird testing in the development phase and utilization during the production program. c It includes recommendations for simulation, component development tests, system integration and lessons learned
A-6A3 Flight Control and Vehicle Management Systems Cmt
Recent Tesla models contain four integrated onboard cameras that serve the Autopilot and Self-Driving Capabilities of the vehicle and act as a dashcam by recording footage to a local USB drive. The purpose of this study is to analyze the footage recorded by the integrated cameras and determine its suitability for speed determinations of both the host vehicle and surrounding vehicles through photogrammetry analyses. The front and rear cameras of the test vehicle (2019 Tesla Model 3) were calibrated for focal length and lens distortion characteristics. Two types of tests were performed to determine host vehicle speed: constant-speed and acceleration. Several frames from each test were analyzed. The distance between camera locations was used to gather vehicle speed through a time distance analysis. These speeds were compared to those gathered via the onboard GPS instrumentation. Two additional types of tests were performed to determine surrounding vehicle speeds: a vehicle approaching
Molnar, Benjamin T.Peck, Louis R.
This SAE Aerospace Recommended Practice (ARP) defines all the relevant issues that affect the generation of an Interface Control Document for Mechanical Actuation Sub-Systems. It is intended to provide to all parties involved with the generation of Mechanical Actuation Sub-Systems, a definition of documentation, drawings, reports and design parameters required to assure a successful development of mechanical actuation sub-systems for Aerospace-Military and Commercial applications
A-6B3 Electro-Mechanical Actuation Committee
This SAE Aerospace Information Report (AIR) provides descriptions of aircraft flight control actuation system failure-detection methods. The fault-detection methods are those used for ground and in-flight detection of failures in electrohydraulic actuation systems for primary flight controls
A-6A3 Flight Control and Vehicle Management Systems Cmt
This SAE Aerospace Recommended Practice (ARP) provides design guidelines for aircraft mechanical control systems and components. Topics contained in this document include design requirements, system design and installation guidelines, and component design practices for primary flight controls, secondary flight controls, and utility controls
A-6A3 Flight Control and Vehicle Management Systems Cmt
This document is applicable to commercial and military aircraft fuel quantity indication systems. It is intended to give guidance for system design and installation. It describes key areas to be considered in the design of a modern fuel system and builds upon experiences gained in the industry in the last 10 years
AE-5A Aerospace Fuel, Inerting and Lubrication Sys Committee
Safety is always a crucial aspect of developing autonomous systems, and the motivation behind this project comes from the need to address the traffic crashes occurring globally on a daily basis. The present work studies the coexistence of the novel rule-based behavioral planning framework with the five key advanced driver assistance system (ADAS) features as proposed in this article to fulfill the safety requirements and enhance the comfort of the driver/passengers to achieve a receding-horizon autopilot. This architecture utilizes data from the sensor fusion and the prediction module for the prediction time horizon of 2 s iteratively, which is continuously moving forward (hence, the receding horizon), and helps the behavior planner understand the intent of other vehicles on the road in advance. Further, that information helps the behavior planner make an appropriate decision regarding the activation of specific ADAS features to drive safely on the highway, and that decision is being
Waghchoure, Mayur RajendraPatel, Jash KiritbhaiSanghai, NikunjKanoun, SaraJohn, Reuben ThomasGupta, GauravDeshpande, Bhargav NarsinhaDorle, Aniruddha
In large vehicles, controlled suspension systems play a vital role in balancing the trade-off between ride comfort and vehicle stability. This article attempts to improve the semi-active stability augmentation system (S-SAS) to provide enhanced passenger comfort and vehicle stability irrespective of the road terrain. A type-1 (T1) fuzzy attitude control strategy is developed to mitigate the loop interactions and limitations in optimizing control gains between the heave and pitch with roll motions. The inner loop called ride control uses a Mamdani interval type-2 (IT2) fuzzy logic control (FLC) to accommodate the system uncertainties and nonlinearities. Semi-active type voice-oil-actuated electrohydraulic (EH) dampers are used to provide controlled damping to suspension systems. The algorithm is deployed in a microcontroller-based hardware, and its performance is tested outdoor for bumpy road conditions at different speeds. A realistic model of the large van in CarSim is also used to
Rajasekharan Unnithan, Anand RajSubramaniam, Senthilkumar
This SAE Aerospace Standard (AS) covers the following basic types: Type I - Pitot pressure, straight and L-shaped, electrically heated. Type II - Pitot and static pressures, straight and L-shaped, electrically heated
A-4ADWG Air Data Subcommittee
This SAE Aerospace Standard (AS) specifies minimum performance requirements for pressure altimeter systems other than air data computers. This document covers altimeter systems that measure and display altitude as a function of atmospheric pressure. The pressure transducer may be contained within the instrument display case or located remotely. Requirements for air data computers are specified in AS8002. Some requirements for nontransducing servoed altitude indicators are included in AS791. This document does not address RVSM requirements because general RVSM requirements cannot be independently detailed at the component level. The instrument system specified herein does not include aircraft pressure lines. Unless otherwise specified, whenever the term “instrument” is used, it is to be understood to be the complete system of pressure transducer components, any auxiliary equipment, and display components. The test procedures specified herein apply specifically to mechanical type
A-4ADWG Air Data Subcommittee
General Atomics Aeronautical Systems, Inc., Poway, CA 858-312-2810
In the field of space technology, Centre Suisse d’Electronique et de Microtechnique (CSEM) has been a partner of the European Space Agency (ESA) for many years. One focus of their joint research is eliminating vibration emissions originating from components aboard satellites. In addition to limiting the precision of attitude control for satellites, these micro-vibrations lead to higher energy consumption and (in the case of imaging missions) cause deterioration of image quality
Automated Driving Systems (ADSs) for road vehicles will be capable of performing the entire Dynamic Driving Task (DDT) without the active involvement of a human driver. Further, many ADSs will use Machine Learning (ML) to progressively adapt their driving functionality during in-service operation. This presents challenges for traditional regulatory frameworks, which do not readily support automated driving without a human driver or support safety-critical systems using ML to modify driving functionality post-market entry. However, these challenges are not entirely unique to ADSs. A review was undertaken into approaches taken in other domains to assure safety-critical systems that enable automated operation and adaptive functionality. Other transport modes were reviewed, including adaptive flight control systems in aviation, autonomous ship control systems in maritime, and automated train operation in rail. Non-transport domains were also reviewed, including medical devices in
Ballingall, StuartSarvi, MajidSweatman, Peter
This SAE Aerospace Information Report (AIR) provides a review of real-time modeling methodologies for gas turbine engine performance. The application of real-time models and modeling methodologies are discussed. The modeling methodologies addressed in this AIR concentrate on the aerothermal portion of the gas turbine propulsion system. Characteristics of the models, the various algorithms used in them, and system integration issues are also reviewed. In addition, example cases of digital models in source code are provided for several methodologies
S-15 Gas Turbine Perf Simulation Nomenclature and Interfaces
This SAE Aerospace Information Report (AIR) provides data and general analysis methods for calculation of internal and external, pressurized and unpressurized airplane compartment pressures during rapid discharge of cabin pressure. References to the applicable current FAA and EASA rules and advisory material are provided. While rules and interpretations can be expected to evolve, numerous airplanes have been approved under current and past rules that will have a continuing need for analysis of production and field modifications, alterations and repairs. The data and basic principles provided by this report are adaptable to any compartment decompression analysis requirement
AC-9 Aircraft Environmental Systems Committee
This SAE Aerospace Recommended Practice (ARP) provides guidelines for the creation of specifications for the Motor Control Electronics (MCE) that are used for operating electrically powered actuators including: Electromechanical Actuators (EMAs) Electrohydrostatic Actuators (EHAs) Electric Back-Up Hydraulic Actuators (EBHAs
A-6B2 Electrohydrostatic Actuation Committee
While real-time positioning computed by standard GPS service is adequate for some onboard applications, inherent position discontinuities are not acceptable for high-precision instrument applications, such as view-period prediction and maneuver planning, both of which are computations that require a continuous prediction of the spacecraft state. Real-time positioning also requires simultaneous measurements from four GPS satellites, a mission-limiting factor that must be considered
SENER Aeroespacial Madrid, Spain (+34) 918077318
This document establishes the minimum requirements for ground-based aircraft deicing/anti-icing methods and procedures to ensure the safe operation of aircraft during icing conditions on the ground. This document does not specify the requirements for particular aircraft models. The application of the procedures specified in this document are intended to effectively remove and/or prevent the accumulation of frost, snow, slush, or ice contamination which can seriously affect the aerodynamic performance and/or the controllability of an aircraft. The principal method of treatment employed is the use of fluids qualified to AMS1424 (Type I fluid) and AMS1428 (Type II, III, and IV fluids). All guidelines referred to herein are applicable only in conjunction with the applicable documents. Due to aerodynamic and other concerns, the application of deicing/anti-icing fluids shall be carried out in compliance with engine and aircraft manufacturer’s recommendations
G-12M Methods Committee
This document collates the ways and means that existing sensors can identify the platform’s exposure to volcanic ash. The capabilities include real-time detection and estimation, and post flight determinations of exposure and intensity. The document includes results of initiatives with the Federal Aviation Administration (FAA), the European Aviation Safety Agency (EASA), the International Civil Aviation Organization (ICAO), Transport Canada, various research organizations, Industry and other subject matter experts. The document illustrates the ways that an aircraft can use existing sensors to act as health monitoring tools so as to assess the operational and maintenance effects related to volcanic ash incidents and possibly help determine what remedial action to take after encountering a volcanic ash (VA) event. Finally, the document provides insight into emerging technologies and capabilities that have been specifically pursued to detect volcanic ash encounters but are not yet a part
HM-1 Integrated Vehicle Health Management Committee
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