Aerodynamically Alleviated Marine Vehicle (AAMV): Bridging the Maritime-to-Air Domain

2015 ◽  
Author(s):  
Daniel James ◽  
Maurizio Collu
Keyword(s):  
High Speed ◽  
High Performance ◽  
Ground Effect ◽  
Full Potential ◽  
Conceptual Approach ◽  
Aerodynamic Properties ◽  
Improved Performance ◽  
Lifting Surfaces ◽  
The Stability ◽  
Marine Vehicle

As high performance marine vessels with improved performance characteristics are being requested by governments (DARPA 2015) and commercial operators, the Aerodynamically Alleviated Marine Vehicle (AAMV) provides a solution that combines speeds typical of rotary-wing and light fixed-wing aircraft with payload and loitering ability found in current high speed craft. The innovative AAMV hybrid aero-marine platform utilizes an alternative implementation of wing-in-ground effect (WIG), a proven technology with a fascinating history of high speed marine operation. This paper outlines some challenges and the work completed towards the development of a hybrid class of vessel that is able to bridge the maritime-to-air domain, comfortably operating in the water surface yet still delivering the speed of aircraft during an airborne cruise phase. An overview of current WIG design is briefly presented, leading to the conceptual approach for the AAMV. Development and assessment of the aerodynamic properties of the lifting surfaces are shown, with analysis of several wing profiles and their effect on the total lift force, drag force, and pitching moment that directly influence the stability characteristics of the vehicle. A methodology for sizing an appropriate platform is summarized, along with experimental results of a high speed hullform with characteristics suitable for this intended application. Finally, particulars of a potential AAMV are derived using an iterative numerical method and briefly compared to current craft. For close to a century, the influence of ground effect has promised economy for low-skimming flight over smooth water (Raymond 1921), a promise that has yet to reach its full potential.

Sensorless Grey Prediction Fuzzy Direct Torque Control for High-Speed Permanent Magnet Synchronous Motor

2012 ◽  
Vol 220-223 ◽  
pp. 1040-1043
Author(s):  
Hong Cui ◽  
You Qing Gao
Keyword(s):  
Permanent Magnet ◽  
High Speed ◽  
High Performance ◽  
Permanent Magnet Synchronous Motor ◽  
Direct Torque Control ◽  
Synchronous Motor ◽  
Torque Control ◽  
Adjustment Process ◽  
Grey Prediction ◽  
The Stability

High-speed permanent magnet synchronous motor (PMSM) is more and more widely applied in high precision processing and high-performance machines. It is very important to research practical control strategy for the stability operation of the high-speed PMSM. The strategy of sensorless grey prediction fuzzy direct torque control (DTC) is proposed which is suitable for high-speed PMSM control system. The method of prediction fuzzy control based on DTC is used to gain the flux, torque and flux oriented angle through the prediction model of the motor parameters. The best control scheme is gained by fuzzy reasoning to overcome the lag on the system making the adjustment process stable and realizing accurate predictive control. Thereby, the dynamic response of the system, anti-disturbance capability and control accuracy can be improved.

Real-Time Validation and Control Environment for Parallel Robot Control Design

2011 ◽  
Author(s):  
A. Zubizarreta ◽  
E. Portillo ◽  
I. Cabanes ◽  
M. Marcos ◽  
Ch. Pinto
Keyword(s):  
High Speed ◽  
High Performance ◽  
Experimental Testing ◽  
Control Design ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Full Potential ◽  
Control Environment ◽  
High Level ◽  
And Control

Due to their high performance when executing high-speed and accurate tasks, parallel robots have became the focus of many researchers and companies. However, exploiting the full potential of these robots requires a correct mechatronic design, in which the designed mechanism has to be controlled by a suitable control law in order to achieve the maximum performance. In this paper a novel Validation and Control Environment (VALIDBOT) is proposed as a support for the control design and experimental testing stages of these robots. The proposed open and flexible environment is designed to meet rapid prototyping requirements, offering a high level framework for both students and researchers. The capabilities of the environment are illustrated with an application case based on a 5R parallel robot prototype in which a modified CTC controller is tested.

scholarly journals Robust state dependent Riccati equation variable impedance control for robotic force-tracking tasks

2020 ◽  
Vol 4 (4) ◽  
pp. 507-519
Author(s):  
Loris Roveda ◽  
Dario Piga
Keyword(s):  
Riccati Equation ◽  
High Performance ◽  
Impedance Control ◽  
Industrial Robots ◽  
Intrinsic Variability ◽  
State Dependent ◽  
Force Tracking ◽  
Lqr Controller ◽  
Improved Performance ◽  
The Stability

AbstractIndustrial robots are increasingly used in highly flexible interaction tasks, where the intrinsic variability makes difficult to pre-program the manipulator for all the different scenarios. In such applications, interaction environments are commonly (partially) unknown to the robot, requiring the implemented controllers to take in charge for the stability of the interaction. While standard controllers are sensor-based, there is a growing need to make sensorless robots (i.e., most of the commercial robots are not equipped with force/torque sensors) able to sense the environment, properly reacting to the established interaction. This paper proposes a new methodology to sensorless force control manipulators. On the basis of sensorless Cartesian impedance control, an Extended Kalman Filter (EKF) is designed to estimate the interaction exchanged between the robot and the environment. Such an estimation is then used in order to close a robust high-performance force loop, designed exploiting a variable impedance control and a State Dependent Riccati Equation (SDRE) force controller. The described approach has been validated in simulations. A Franka EMIKA panda robot has been considered as a test platform. A probing task involving different materials (i.e., with different stiffness properties) has been considered to show the capabilities of the developed EKF (able to converge with limited errors) and controller (preserving stability and avoiding overshoots). The proposed controller has been compared with an LQR controller to show its improved performance.

Propellers for High-Performance Craft

1978 ◽  
Vol 15 (04) ◽  
pp. 335-380 ◽  
Author(s):  
John L. Allison
Keyword(s):  
High Speed ◽  
High Performance ◽  
Surface Effect ◽  
Historical Review ◽  
Full Scale ◽  
Design Procedures ◽  
Surface Effect Ship ◽  
Design Selection ◽  
Improved Performance ◽  
Model Versus

This paper presents a brief historical review of marine propeller development leading to modern design, selection, and matching methods for high-performance craft such as planing hulls, hydrofoils and surface effect ships. Subcavitating propeller theory is summarized, and some limitations are discussed with regard to high-speed applications. An outline of supercavitating propeller theory is provided together with brief details of design procedures and the limitations of available data. The special problems of application of supercavitating propellers to surface effect ships are discussed briefly. Topics include sidehull installations, matching for hump and cruise, need for partial submergence and controllable pitch, strength considerations, and model versus full-scale performance. A review of recent progress in the application of supercavitating propellers to surface effect ships is presented, including comparisons of predicted full-scale blade pressures and stresses with actual full-scale measurements of speeds up to 80 knots. Future trends and goals are discussed, including development of improved performance prediction methods, rational structural design procedures, and new types of installation configuration. Much of the new information contained in this paper arises out of work performed under contract for the U. S. Navy Surface Effect Ship Program Office (PMS304) by Bell Aerospace Textron.

Vacuum System to Minimize the Specimen Contamination of High-Performance EM

1977 ◽  
Vol 35 ◽  
pp. 68-69
Author(s):  
N. Yoshimura ◽  
K. Shirota ◽  
T. Etoh
Keyword(s):  
Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
High Vacuum ◽  
Vacuum System ◽  
Pump System ◽  
Pumping System ◽  
Diffusion Pump ◽  
Almost All ◽  
Cascade Type

One of the most important requirements for a high-performance EM, especially an analytical EM using a fine beam probe, is to prevent specimen contamination by providing a clean high vacuum in the vicinity of the specimen. However, in almost all commercial EMs, the pressure in the vicinity of the specimen under observation is usually more than ten times higher than the pressure measured at the punping line. The EM column inevitably requires the use of greased Viton O-rings for fine movement, and specimens and films need to be exchanged frequently and several attachments may also be exchanged. For these reasons, a high speed pumping system, as well as a clean vacuum system, is now required. A newly developed electron microscope, the JEM-100CX features clean high vacuum in the vicinity of the specimen, realized by the use of a CASCADE type diffusion pump system which has been essentially improved over its predeces- sorD employed on the JEM-100C.

PHAX-SCAN: Functional integration of a Scanning Electron Microscope and an energy-dispersive x-ray analyser

1989 ◽  
Vol 47 ◽  
pp. 56-57
Author(s):  
Marc H. Peeters ◽  
Max T. Otten
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
Functional Integration ◽  
Energy Dispersive ◽  
X Rays ◽  
X Ray ◽  
High Speed Analysis ◽  
Scanning Electron

Over the past decades, the combination of energy-dispersive analysis of X-rays and scanning electron microscopy has proved to be a powerful tool for fast and reliable elemental characterization of a large variety of specimens. The technique has evolved rapidly from a purely qualitative characterization method to a reliable quantitative way of analysis. In the last 5 years, an increasing need for automation is observed, whereby energy-dispersive analysers control the beam and stage movement of the scanning electron microscope in order to collect digital X-ray images and perform unattended point analysis over multiple locations.The Philips High-speed Analysis of X-rays system (PHAX-Scan) makes use of the high performance dual-processor structure of the EDAX PV9900 analyser and the databus structure of the Philips series 500 scanning electron microscope to provide a highly automated, user-friendly and extremely fast microanalysis system. The software that runs on the hardware described above was specifically designed to provide the ultimate attainable speed on the system.

The bright future of digital imaging in scanning electron microscopy

1993 ◽  
Vol 51 ◽  
pp. 768-769
Author(s):  
M. T. Postek ◽  
A. E. Vladar
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Digital Imaging ◽  
High Speed ◽  
High Performance ◽  
Mass Storage ◽  
Analog To Digital ◽  
Central Processing ◽  
Digital Imaging Technology ◽  
Scanning Electron

One of the major advancements applied to scanning electron microscopy (SEM) during the past 10 years has been the development and application of digital imaging technology. Advancements in technology, notably the availability of less expensive, high-density memory chips and the development of high speed analog-to-digital converters, mass storage and high performance central processing units have fostered this revolution. Today, most modern SEM instruments have digital electronics as a standard feature. These instruments, generally have 8 bit or 256 gray levels with, at least, 512 × 512 pixel density operating at TV rate. In addition, current slow-scan commercial frame-grabber cards, directly applicable to the SEM, can have upwards of 12-14 bit lateral resolution permitting image acquisition at 4096 × 4096 resolution or greater. The two major categories of SEM systems to which digital technology have been applied are:In the analog SEM system the scan generator is normally operated in an analog manner and the image is displayed in an analog or "slow scan" mode.

Dietary Vitamin and Stability of Oral Anticoagulation: Proposal of a Diet with Constant Vitamin K1 Content

1997 ◽  
Vol 77 (03) ◽  
pp. 504-509 ◽  
Author(s):  
Sarah L Booth ◽  
Jacqueline M Charnley ◽  
James A Sadowski ◽  
Edward Saltzman ◽  
Edwin G Bovill ◽  
...  
Keyword(s):  
Dietary Intake ◽  
Vitamin K ◽  
High Performance ◽  
Case Reports ◽  
Food Composition ◽  
Dietary Guidelines ◽  
Dietary Vitamin ◽  
Vitamin K1 ◽  
The Stability ◽  
The Impact

SummaryCase reports cited in Medline or Biological Abstracts (1966-1996) were reviewed to evaluate the impact of vitamin K1 dietary intake on the stability of anticoagulant control in patients using coumarin derivatives. Reported nutrient-drug interactions cannot always be explained by the vitamin K1 content of the food items. However, metabolic data indicate that a consistent dietary intake of vitamin K is important to attain a daily equilibrium in vitamin K status. We report a diet that provides a stable intake of vitamin K1, equivalent to the current U.S. Recommended Dietary Allowance, using food composition data derived from high-performance liquid chromatography. Inconsistencies in the published literature indicate that prospective clinical studies should be undertaken to clarify the putative dietary vitamin K1-coumarin interaction. The dietary guidelines reported here may be used in such studies.

A Statistical Study of Process Variables to Optimize a High Speed Curtain Coater: Part I

TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 20-26 ◽  
Author(s):  
PEEYUSH TRIPATHI ◽  
MARGARET JOYCE ◽  
PAUL D. FLEMING ◽  
MASAHIRO SUGIHARA
Keyword(s):  
Boundary Layer ◽  
Experimental Design ◽  
High Speed ◽  
Statistical Study ◽  
Process Variables ◽  
High Speeds ◽  
The Stability ◽  
Air Removal ◽  
Removal System

Using an experimental design approach, researchers altered process parameters and material prop-erties to stabilize the curtain of a pilot curtain coater at high speeds. Part I of this paper identifies the four significant variables that influence curtain stability. The boundary layer air removal system was critical to the stability of the curtain and base sheet roughness was found to be very important. A shear thinning coating rheology and higher curtain heights improved the curtain stability at high speeds. The sizing of the base sheet affected coverage and cur-tain stability because of its effect on base sheet wettability. The role of surfactant was inconclusive. Part II of this paper will report on further optimization of curtain stability with these four variables using a D-optimal partial-facto-rial design.

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