Road disturbances introduce a combination of vertical and angular motions of pitch and roll that affect the stability and ride comfort of a military vehicle. This study focuses on the enhancement of stability and ride comfort. A half car model with 4 Degree of freedom (DOF), whose vehicle chassis can pitch and bounce, is modeled in Simulink with the objective of attitude control using Stability Augmentation System (SAS). Control is implemented at two levels, one at the suspension level which is an open loop control for improving the ride and the other is closed loop for controlling the body motion by sensing pitch and bounce displacement. The inner loop is utilised to reject the effect of road disturbances and outer loop is to stabilize heave and pitch response. In other words, inner loop provides ride control and the outer loop provides the attitude control. The control force is obtained by using an active damper.
This SAE Aerospace Information Report (AIR) has been prepared to provide information regarding options for optical control of fluid power actuation devices. It is not intended to establish standards for optical fluid power control, but rather is intended to provide a baseline or foundation from which standards can be developed. It presents and discusses approaches for command and communication with the actuation device via electro-optic means. The development of standards will require industry wide participation and cooperation to ensure interface commonality, reliability, and early reduction to practice. To facilitate such participation, this document provides potential users of the technology a balanced consensus on its present state of development, the prospects for demonstration of production readiness, and a discussion of problem areas within this technology.
Aerospace Qualified Electronic Component (AQEC) Requirements, Volume 1 - Integrated Circuits and Semiconductors
This Standard applies to integrated circuits and semiconductors exhibiting the following attributes: a. A minimum set of requirements, or information provided by the part manufacturer, which will allow a standard COTS component to be designated AQEC by the manufacturer. b. As a minimum, each COTS component (designated AQEC) will have been designed, fabricated, assembled, and tested in accordance with the component manufacturer's requirements for standard data book components. c. Qualification of, and quality systems for, the COTS components to be designated as AQEC shall include the manufacturer's standards, operating procedures, and technical specifications. d. Components manufactured before the manufacturer has addressed AQEC requirements, but utilizing the same processes, are also considered AQEC compliant. e. Additional desired attributes of a device designated AQEC (that will support AQEC users) are found in Appendix B of this standard.
This SAE Aerospace Information Report (AIR) contains Lessons Learned from aerospace actuation, control and fluid power systems technologies. The lessons were prepared by engineers from the aerospace industry and government services as part of the work of SAE Committee A-6, Aerospace Actuation, Control and Fluid Power Systems.
Establish minimum requirements for procedures, materials and systems for protecting electronic components and assemblies from adverse environments in commercial and government applications.
Materials Infusing Lightweight Composite Structures Business Jets Business Jets Bounce Back
This Aerospace Information Report (AIR) provides information on the thrust vectoring flight control systems incorporated on various aircraft development programs and production military aircraft. This report includes V/STOL aircraft thrust vector applications in addition to recommendations for use of thrust vectoring for the improvement of low speed maneuverability in conventional aircraft. Descriptions of each aircraft are provided along with a summary of the thrust vector control system, and, mechanical design methodologies used. Block diagrams, system schematics, and, several system level components are presented.
This specification provides guidance for the physical layer of optical networks which use Wavelength Division Multiplexing (WDM), within the SAE AS5659 WDM LAN specifications document family. The physical layer consists of cabling and connectors which provide the optical interconnections between the components and portions of the network. Performance requirements for general link connections- called the physical layer- are described. Specific sets of documents are identified, corresponding to each of several environments, which describe physical layer design, installation, maintenance, and training.
This document describes the Client Adaptation Element (CAE), the set of functions that provides access and aggregation capability for the WDM LAN, within the SAE AS5659 WDM LAN specifications document family. In the WDM LAN, the CAE fits in between the Optical Backbone, which provides transmission of data over the transparent network, and the clients which the network serves. The complexity of the CAE depends on the types and number of clients.
This document describes network management and control facilities for the WDM LAN, within the SAE AS5659 WDM LAN specifications document family. Unlike like point-to-point solutions, networks require a control plane to allocate the shared network resources and a management plane which provides a disciplined approach to configuring and monitoring the network. Within a Wavelength Division Multiplexed (WDM) environment, management and control provides wavelength selection and routing for traffic that is processed. The extent of network management and control depends on the design of the network, and can range from hardwired wavelengths to dynamic wavelength allocation with damage recovery.
This document provides a specification for the WDM Optical Backbone Network (OBN) within the SAE AS5659 WDM LAN specifications document family. The specification applies to any optical network which uses Wavelength Division Multiplexing (WDM) in any optical media, and describes a transparent optical network that contains optical components (i.e. without Optical-to-Electrical conversion). The specification describes optical network elements (ONE) that perform optical transport, optical add/drop, optical amplification, optical routing, and optical switching functions. Performance limits are given for conforming optical signal interfaces and transfer functions for the ONEs, as well as architectures comprising combinations of them. This specification will enable network and systems engineers to design and use scalable and upgradable WDM based optical networks aboard mobile platforms.
This SAE Aerospace Information Report (AIR) is devoted to the challenges of applying optics to new advanced RF analog systems only; digital data link applications are covered elsewhere in protocol/architecture specific documents like Fibre Channel, ATM, Ethernet, Sonet, etc.
The ARP shall cover the objectives and activities of Verification & Vallidation Processes required to assure high quality and/or criticality level of an IVHM Systems and Software.
This specification covers constant displacement hydraulic motors, generally remotely mounted, using hydraulic fluid under pressure as the energy transfer medium for driving various accessories. Hydraulic motors shall be suitable for use in aircraft hydraulic systems conforming to and as defined in MIL-H-5440 and MIL-H-8891 as applicable.
This document recommends design and performance criteria for aircraft lighting systems used to illuminate flight deck controls, luminous visual displays used for transfer of information, and flight deck background and instrument surfaces that form the flight deck visual environment. This document is for commercial transport aircraft except for applications requiring night vision compatibility.
Most of the Trimmable Horizontal Stabilizer Actuators (THSA) feature a dual structural load path, the primary load path being loaded, the secondary load path being normally unloaded, or both load paths sharing in parallel the Horizontal Stabilizer load. This document describes existing methods for detecting rupture or disconnection of loaded load paths as an overview for those specifying or designing Horizontal Stabilizer Trim Actuators in order to compare existing solutions as reference for implementation in new aircraft programs.
This document defines methods to exchange data about the health of a fiber optic network.
This document defines performance standards which fiber optic cable splices must meet in order to be accepted for use in aerospace platforms and environments.
Propulsion: Energy Sources Flying on vegetation Avionics/Electronics Avionics heat up, in a good way Unmanned Vehicles Reaching the benchmark in secure unmanned vehicle software Thermal Management Submersion and directed flow cooling technology for military applications RF & Microwave Technology Airborne antenna considerations for C-Band telemetry systems Software-designed system improves wireless test speed and coverage
This SAE Aerospace Information Report (AIR) examines the need for and the application of a power train usage metric that can be used to more accurately determine the TBO for helicopter transmissions. It provides a formula for the translation of the recorded torque history into mechanical usage. It provides examples of this process and recommends a way forward. This document of the SAE HM-1 IVHM Committee is not intended as a legal document and does not provide detailed implementation steps, but does address general implementation concerns and potential benefits.
This is the electronic format of the Journal.
Abstract Performance of Avionics systems is dictated by the timely availability and usage of critical health parameters. Various sensors are extensively used to acquire and communicate the desired parameters. In today's scenario, sensors are hardwired. The number of sensors is growing due to automation which increases the accuracy of intended Aircraft functions. Sensors are distributed all over the Aircraft and they are connected through wired network for signal processing and communication. LRUs (Line Replaceable Unit) which are integrating various sensors also use a wired approach for communication. The use of a wired network approach poses challenges in terms of cable routing, stray capacitances, noise, mechanical structure and added weight to the structure. The weight of cables contributes significantly to the overall weight of the aircraft. As the weight of Aircraft increases, the required fuel quantity also increases. The Key driver for Airline operational cost is fuel.
Abstract Airship designers research application versions of systems with several ballonets for adjustment of airship roll and/or pitch as a whole. This requires effective automatic status management of each separate ballonet. But multi-ballonet system control issue encounters the absence of industrially measurable variables of each separate ballonet status. Thus status control issue of the system becomes uncertain. The fact requires the issue studying and shaping new scientific and technical solutions. This publication represents research results implying that fairly simple implementation and effective result can be achieved by application of fuzzy control concept. Its application is built on generating the representative quantity of fuzzy production rules. They are based on present set evaluation of known parameters and measured variables. This results in fuzzy but meaningful image of ballonet system status and airship as a whole.
Abstract The paper provides an introduction into IEEE-1394, AS5643 and related documents. It then explores the I/O Technology Suitability Study criteria used to originally select IEEE-1394b (Beta) as the Vehicle System Data Bus for the F-35 Joint Strike Fighter and update each criterion with new information based on more than a decade of experience and use in not only the F-35 but several other programs. Based on the suitability study criteria, the reader gains insight into how and why programs like the F-35, which implements dozens of AS5643/IEEE-1394 devices per plane, utilize AS5643/IEEE-1394 for its vehicle system network. This unprecedented use of a high speed (491.52Mb/s) serial interface on an aircraft proves the capability of AS5643/1394, and opens the door for higher bandwidth communication between the Control Computer and remote nodes.
Experimental Evaluation of Two Pitot Free Analytical Redundancy Techniques for the Estimation of the Airspeed of an UAV
Abstract A measurement device that is extremely important for Unmanned Aerial Vehicle (UAV) guidance and control purposes is the airspeed sensor. As the parameters of feedback control laws are conventionally scheduled as a function of airspeed, an incorrect reading (e.g. due to a sensor fault) of the Pitot-static tube could induce an incorrect feedback control action, potentially leading to the loss of control of the UAV. The objective of this study is to establish the accuracy and reliability of the two airspeed estimation techniques for eventual use as the basis for real-time fault detection of anomalies occurring on the Pitot-static tube sensor. The first approach is based on an Extended Kalman Filter (EKF) and the second approach is based on Least Squares (LS) modeling. The EKF technique utilizes nonlinear kinematic relations between GPS, Inertial Measurement Unit and Air Data System signals and has the advantage of independence from knowledge of the aircraft model.
Evaluation of Sensor Failure Detection, Identification and Accommodation (SFDIA) Performance Following Common-Mode Failures of Pitot Tubes
Abstract Recent catastrophic air crashes have shown that physical redundancy is not a foolproof option for failures on Air Data Systems (ADS) on an aircraft providing airspeed measurements. Since all the redundant sensors are subjected to the same environmental conditions in flight, a failure on one sensor could occur on the other sensors under certain conditions such as extreme weather; this class of failure is known in the literature as “common mode” failure. In this paper, different approaches to the problem of detection, identification and accommodation of failures on the Air Data System (ADS) of an aircraft are evaluated. This task can be divided into component tasks of equal criticality as Sensor Failure Detection and Identification (SFDI) and Sensor Failure Accommodation (SFA). Data from flight test experiments conducted using the WVU YF-22 unmanned research aircraft are used.
Abstract This paper summarizes the Power, Avionics and Software (PAS) 1.0 subsystem integration testing and test results that occurred in August and September of 2013. This paper covers the capabilities of each PAS assembly to meet integration test objectives for non-safety critical, non-flight, non-human-rated hardware and software development. This test report is the outcome of the first integration of the PAS subsystem and is meant to provide data for subsequent designs, development and testing of the future PAS subsystems. The two main objectives were to assess the ability of the PAS assemblies' to exchange messages and to perform audio tests of both inbound and outbound channels. This paper describes each test performed, defines the test, the data, and provides conclusions and recommendations.
A Hybrid Projectile (HP) is a ballistically launched round that transforms into an Unmanned Aerial Vehicle (UAV) at a designated point during flight. Aerodynamic control surfaces and associated control laws were sought that would extend the projectile's range using body lift and include guidance for a selected point of impact. Several challenges were encountered during the modification of an existing projectile, in this case a 40mm round, to achieve range extension and controllability. The control surfaces must be designed to allow for de-spin, controllability, and natural static stability. Also, a control system with laws and guidance relationships between heading, pitch or glide rate, and the associated aerodynamic surface movements needed to be developed. The designed aerodynamic surfaces, external ballistics, and control methods developed were modeled in a projectile flight simulator built in MATLAB.
Energy Analysis of Electromechanical Actuator under Simulated Aircraft Primary Flight Control Surface Load
Abstract The purpose of this study is to set up a laboratory test apparatus to analyze aircraft flight control EMAS' electrical and thermal energy flow under transient and dynamic flight profiles. A hydraulic load frame was used to exert load to the EMA. The actuator was placed within an environmental chamber which simulates ambient temperature as function of altitude. The simulated movement or stroke was carried out by the EMA. The under test EMA's dynamic load, stroke, and ambient temperature were synchronized through a real time Labview DAQ system. Motor drive voltage, current, regenerative current, and motor drive and motor winding temperature were recorded for energy analysis. The EMA under test was subjected to both transient and holding load laid out in a test matrix.