Display:

Results

Viewing 1 to 30 of 2896
Technical Paper
2014-10-13
Chunshan Li, Guoying Chen, Changfu Zong
This paper presents a fault-tolerant control (FTC) approach for four-wheel independently driven and steered (4WID/4WIS) electric vehicles. An adaptive control-based passive fault-tolerant controller is designed to improve vehicle safety, performance and maneuverability when an actuator fault happens. The proposed fault tolerant control method consists of the following three parts: 1) a fault detection and diagnosis (FDD) module that monitors vehicle driving condition, detects and diagnoses actuator failures with the inequality constraints ; 2) a motion controller that computes the generalized forces/moments to track the desired vehicle motion using Model Predictive Control (MPC); 3) a reconfigurable control allocator that redistributes the generalized forces/moments to four wheels with equality constrained optimization. The FTC approach is based on the reconfigurable control allocation which reallocates the generalized forces/moments among healthy actuators once the actuator failures is detected.
Technical Paper
2014-09-30
Alexander Sappok, Leslie Bromberg
Abstract Diesel Particulate Filters (DPF) are a key component in many on- and off-road aftertreatment systems to meet increasingly stringent particle emissions limits. Efficient thermal management and regeneration control is critical for reliable and cost-effective operation of the combined engine and aftertreatment system. Conventional DPF control systems predominantly rely on a combination of filter pressure drop measurements and predictive models to indirectly estimate the soot loading state of the filter. Over time, the build-up of incombustible ash, primarily derived from metal-containing lubricant additives, accumulates in the filter to levels far exceeding the DPF's soot storage limit. The combined effects of soot and ash build-up dynamically impact the filter's pressure drop response, service life, and fuel consumption, and must be accurately accounted for in order to optimize engine and aftertreatment system performance. This work applied a radio frequency (RF) sensor to directly monitor diesel particulate filter soot and ash levels, thereby enabling direct feedback control of the filter based on its actual loading state.
Technical Paper
2014-09-16
Joseph Dygert, Melissa Morris, Patrick Browning
Abstract The high demand for traditional air traffic as well as increased use of unmanned aerial systems (UAS) has resulted in researchers examining alternative technologies which would result in safer, more reliable, and better performing aircraft. Active methods of aerodynamic flow control may be the most promising approach to this problem. Research in the area of aerodynamic control is transitioning from traditional mechanical flow control devices to, among other methods, plasma actuators. Plasma actuators offer an inexpensive and energy efficient method of flow control. Dielectric Barrier Discharge (DBD), one of the most widely studied forms of plasma actuation, employs an electrohydrodynamic (EHD) device which uses dominant electric fields for actuation. Unlike traditional flow control methods, a DBD device operates without moving components or mass injection methods. Publications discussing the optimization of DBD flow control versus a single variable such as gap width, voltage, dielectric constant, etc., have been widely published, and instigated a 2003 paper published by the IEEE-DEIS-EHD Technical Committee titled “Recommended International Standard for Dimensionless Parameters Used in Electrohydrodynamics.”
Technical Paper
2014-09-16
Prashant Vadgaonkar, Ullas Janardhan, Adishesha Sivaramasastry
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. Fuel quantity is a direct function of weight.
Technical Paper
2014-09-16
Ralf D. Pechstedt
Abstract Recently, there has been an increasing interest in Fiber Optic Sensors (FOS) for aircraft applications. Many of the FOS are based on different transducer mechanisms and hence, employ sensor-specific readout systems. However, for ease of maintenance and cost saving purposes, a ‘universal interrogator’ that can be used with at least a large sub-group of sensors is the preferred option for deployment in aircraft. Oxsensis has been developing sensors for harsh environments with focus on land based gas-turbine monitoring and combustion control and more recently is also looking at applying its technology to other areas such as Aerospace and Oil & Gas. In this paper we report on recent progress on the development of a number of FOS and how these could find application in aircraft with a ‘universal interrogator’ concept in mind.
Technical Paper
2014-09-16
Mario Luca Fravolini, Matthew Rhudy, Srikanth Gururajan, Silvia Cascianelli, Marcello Napolitano
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. The LS method is based on explicit knowledge of the aircraft model and has the advantage of on-line computation of the airspeed estimate, with minimal computational effort.
Technical Paper
2014-09-16
Michael Usrey, Kevin Harsh, Alexander Brand, R. Steve McKown, Alireza Behbahani
Abstract Air Force Research Laboratory (AFRL) is pursuing development of advanced, distributed, intelligent, adaptive engine controls and engine health monitoring systems. The goals this pursuit are enhancing engine performance, safety, affordability, operability, and reliability while reducing obsolescence risk. The development of smart, high-bandwidth, high-temperature-operable, wide-range, pressure/temperature multi-sensors, which addresses these goals, is discussed. The resulting sensors and packaging can be manufactured at low cost and operate in corrosive environments, while measuring temperatures up to 2,552 °F (1,400 °C) with simultaneous pressure measurements up to 1,000 psi (68 atm). Such a sensor suite provides unprecedented monitoring of propulsion, energy generation, and industrial systems. The multi-sensor approach reduces control system weight and wiring complexity, design time, and cost, while increasing accuracy and fault tolerance. In situ pressure sensors reduce size and weight while eliminating failures associated with hypo-tube fouling.
WIP Standard
2014-07-31
This SAE Aerospace Standard (AS) defines the testing methods for all aerospace optic cables. The application of the test methods are defined in the slant sheets. Technical, dimensional, mechanical and operating performance requirements for the associated aerospace fiber optic cables are detailed in the applicable specification slant sheet. In the event of conflict between this standard and the slant sheet, the slant sheet shall take precedence.
WIP Standard
2014-07-09
To provide cross reference between test methods across the fiber optics industry.
Standard
2014-07-07
This ARP provides insights on how to perform a cost benefit analysis (CBA) to determine the return on investment that would result from implementing an integrated Health Management (HM) system on an air vehicle. The word “integrated” refers to the combination or “roll up” of sub-systems health management tools to create a platform centric system. The document describes the complexity of features that can be considered in the analysis, the different tools and approaches for conducting a CBA and differentiates between military and commercial applications. This document is intended to help those who might not necessarily have a deep technical understanding or familiarity with HM systems but want to either quantify or understand the economic benefits (i.e., the value proposition) that a HM system could provide. Prognostics is a capability within some HM systems that provides an estimation of remaining useful life (RUL) or time to failure and so Prognostic Health Management (PHM) is used where this predictive element exists.
Standard
2014-07-01
This SAE Aerospace Recommended Practice (ARP) is an application guide for fixed and variable displacement hydraulic motors. It provides details of the characteristics of fixed and variable displacement hydraulic motors, architectures, circuit designs, controls, and typical applications. The applications include airborne and defense vehicles with emphasis on high performance applications.
Magazine
2014-07-01
Global Viewpoints The latest strategies are investigated for vehicle development by automakers and major suppliers. Sports cars embrace array of green technology IMSA Tudor United SportsCar Championship promotes a variety of green technologies to link racing to the road. More gears, more challenges Many strategies, as well as key software and hardware aspects related to controllers, networks, sensors, and actuators, must be considered to keep automatic transmissions shifting smoothly as more gears are added to improve fuel economy. Advancing structural composites Industry experts address the opportunities and challenges involved with moving toward composite-intensive vehicles, including Nissan's effort to produce a high-volume, fully recyclable composite liftgate with low metal content.
Magazine
2014-06-05
Watching for ways to stand above the crowd Sensors monitor a broad range of parameters to help powertrain design teams add features and improve performance.
WIP Standard
2014-05-27
No scope available.
Technical Paper
2014-05-09
John O. Manyala, Todd W. Fritz
Electro-hydraulic actuated systems are widely used in industrial applications due to high torque density, higher speeds and wide bandwidth operation. However, the complexities and the parametric uncertainties of the hydraulic actuated systems pose challenges in establishing analytical mathematical models. Unlike electro-mechanical and pneumatic systems, the nonlinear dynamics due to dead band, hysteresis, nonlinear pressure flow relations, leakages and friction affects the pressure sensitivity and flow gain by altering the system's transient response, which can introduce asymmetric oscillatory behavior and a lag in the system response. The parametric uncertainties make it imperative to have condition monitoring with in-built diagnostics capability. Timely faults detection and isolation can help mitigate catastrophic failures. This paper presents a signal-based fault diagnostic scheme for a gearbox hydraulic actuator leakage detection using the wavelet transform. The novelty of the work is the development of a high fidelity leakage fault detection as low as 0.128 lit/min.
Standard
2014-04-24
This SAE Aerospace Recommended Practice (ARP) establishes software capability guidelines for computer controlled test equipment, hereinafter referred to as automatic test equipment (ATE), for testing hydraulic components. A typical ATE system is shown. The items herein have been selected as potential features which may or may not be applicable to a particular application. This document does not address software development requirements, qualification procedures, or hardware design requirements, but encourages users to refer to existing documents for guidance on such issues.
WIP Standard
2014-04-23
Generate an accompanying document to AS-6129 to define the verification method and criteria for all the requirements contained in AS-6129.
WIP Standard
2014-04-22
This standard defines a generic set of electrical interfaces between a host aircraft (“platform”) and an electro-optic/infrared (EO/IR) sensor. This includes connectors, cabling, fiber optics, signals, and power.
WIP Standard
2014-04-22
This SAE Aerospace Standard (AS) defines the editorial format and policies necessary for the publication of platform/subsystem Interface Control documents. The Common Interface Control Document Format Standard defines a common format for platform to subsystem interface documents to facilitate subsystem integration. This aerospace standard specifies the common technical data sections for the Common Interface Control Document Format down to the third header level for the majority of sub-sections. The Common Interface Control Document Format Aerospace Standard provides a structured document format in appendixes supported by example paragraphs, drawings, etc.
WIP Standard
2014-04-15
This document establishes training guidelines applicable to fiber optic safety training, technical training and fiber awareness for individuals involved in the manufacturing, installation, support, integration and testing of fiber optic systems.
WIP Standard
2014-04-15
This document establishes training guidelines applicable to fiber optic safety training, technical training and fiber awareness for individuals involved in the manufacturing, installation, support, integration and testing of fiber optic systems.
WIP Standard
2014-04-15
This document establishes training guidelines applicable to fiber optic quality assurance technical training for individuals involved in the manufacturing, installation, support, integration and testing of fiber optic systems. Applicable personnel include: Managers Engineers Technicians Trainers/Instructors Third Party Maintenance Agencies Quality Assurance Production
WIP Standard
2014-04-15
This document establishes training guidelines applicable to fiber optic technician technical training for individuals involved in the manufacturing, installation, support, integration and testing of fiber optic systems. Applicable personnel include: Managers Engineers Technicians Trainers/Instructors Third Party Maintenance Agencies Quality Assurance Production
WIP Standard
2014-04-15
This document establishes training guidelines applicable to fiber optic technician, quality assurance, or engineer technical training for individuals involved in the manufacturing, installation, support, integration and testing of fiber optic systems. Applicable personnel include: Managers Engineers Technicians Trainers/Instructors Third Party Maintenance Agencies Quality Assurance Production
WIP Standard
2014-04-15
This document establishes training guidelines applicable to fiber optic installer technical training for individuals involved in the manufacturing, installation, support, integration and testing of fiber optic systems. Applicable personnel include: Managers Engineers Technicians Trainers/Instructors Third Party Maintenance Agencies Quality Assurance Production
WIP Standard
2014-04-15
This document establishes training guidelines applicable to fiber optic installer technical training for individuals involved in the manufacturing, installation, support, integration and testing of fiber optic systems. Applicable personnel include: Managers Engineers Technicians Logisticians Trainers/Instructors Third Party Maintenance Agencies Quality Assurance Shipping Receiving Production Purchasing
Technical Paper
2014-04-01
Stavros Amanatidis, Leonidas Ntziachristos, Zissis Samaras, Chariton Kouridis, Kauko Janka, Juha Tikkanen
Abstract The effect of “Start & Stop” and “Gear Shift Indicator” - two widespread fuel saving technologies - on fuel consumption and particle emissions of a Euro 5 passenger car is evaluated in this paper. The vehicle was subjected to a series of different driving cycles, including the current (NEDC) and future (WLTC) cycles implemented in the European type approval procedure at cold and hot start condition and particle number was measured with an AVL Particle Counter. In addition, we have utilized two Pegasor Particle Sensor units positioned in different locations along the sampling line to assess the impact of the sampling location on the particle characteristics measured during highly transient events. The results showed that the particle number emission levels over the WLTC were comparable to the NEDC ones, whereas NOx emissions were more than twofold higher. Both fuel saving technologies can lead to reduced fuel consumption and, subsequently CO2 emissions, in the order of 5%. However, their impact on particle emissions was not straightforward, as the impact of the DPF loading was found much more significant than the effect of these technologies.
Technical Paper
2014-04-01
Michael Delbaere, Didier Frachon, Gerald Masson
Abstract Many synchronous electric motors require a very accurate position sensor compatible with a sinusoidal control. The purpose of such a control is to enable an efficient and smooth operation enhancing the comfort by limiting vibrations. In some cases related to mechanical constraints, we have to deal with through-shaft design. One can quote for examples power drives for Electric or Hybrid Electric Vehicles as well as for Electric Power Steering motor. More generally, these sensors need to keep a simple and robust design and a restricted number of parts as they are submitted to high vibration levels, a wide temperature range and speeds of several krpm. In order to meet such requirements, MMT has developed a magnetic sensor principle offering a competitive alternative to the conventional inductive resolver type sensors. The basics of this solution is a through shaft angular position sensor using one or two Hall-effect probes. These Hall IC measure the angle of the magnetic field generated by a ring or a disc magnet.
Viewing 1 to 30 of 2896

Filter

  • Book
    28
  • Collection
    1
  • Magazine
    91
  • Technical Paper
    2537
  • Standard
    239
  • Article
    0
  • Article
    0