scholarly journals REMOTE ATTITUDE SENSING BASED ON HIGH-SPEED MUELLER MATRIX ELLIPSOMETRY

2020 ◽  
Vol XLIII-B1-2020 ◽  
pp. 607-614
Author(s):  
S. Zhang ◽  
H. Jiang ◽  
H. Gu ◽  
X. Chen ◽  
S. Liu
Keyword(s):  
Real Time ◽  
High Speed ◽  
Angular Resolution ◽  
Mueller Matrix ◽  
Moving Object ◽  
High Angular Resolution ◽  
High Temporal Resolution ◽  
Theoretical Derivation ◽  
The Real ◽  
Attitude Tracking

Abstract. The attitude metrology of moving objects has always been a hot topic in engineering applications. In this article, a novel optical method based on the high-speed Mueller matrix ellipsometry (MME) is proposed for real-time remote attitude sensing. With the help of an electric level, all the attitude angles of a free-moving object with a birefringent waveplate attached can be simultaneously extracted in real time. Compared with existing ellipsometry-based attitude metrology that can only be used in the transmission mode, the proposed method with the advantages of the high-speed MME can expand the application to both the transmission and reflection modes while maintaining higher accuracy and robustness in an ultra-large measurement range. The basic principle is presented via theoretical derivation, and the change in the Mueller matrix of the birefringent waveplate versus the attitude angles is explored in the simulated experiments. In a series of the dynamic experiments, with the extremely high temporal resolution and accuracy of the high-speed MME, an angular resolution up to 0.00022° and an angular accuracy better than 0.01° are achieved in the real-time attitude tracking of the free-moving object. As an additional benefit, the real-time angular velocity and acceleration of all the attitude angles can be obtained simultaneously. These experimental results demonstrate that the proposed attitude metrology is ready to be applied to the real-time remote attitude sensing with high angular resolution and accuracy.

Application of the Real-Time EtherCAT Technology in Wind Power Control System

2012 ◽  
Vol 580 ◽  
pp. 155-159
Author(s):  
Xiang Ming Wang ◽  
Jin Chao Wang ◽  
Dong Hua Sun
Keyword(s):  
Control System ◽  
Real Time ◽  
Wind Power ◽  
High Speed ◽  
Communication Protocol ◽  
Data Communication ◽  
Data Acquisition System ◽  
Slave System ◽  
The Real ◽  
Wind Power System

In this paper, the real-time EtherCAT technology is introduced in detail, which including operating principle, communication protocol and the superiority performance of EtherCAT i.e. synchronicity, simultaneousness and high speed. To show how to design a slave system that considering the characteristics of application, the method of developing systems based no EtherCAT technology are proposed. Finally, a data acquisition system based on EtherCAT technology is designed. Application of EtherCAT technology can improve the real-time characteristics of data communication in wind power system.

scholarly journals Development of six-degree of freedom strapdown terrestrial INS algorithm

2005 ◽  
Vol 2 (1) ◽  
pp. 155-165
Author(s):  
Baghdad Science Journal
Keyword(s):  
Real Time ◽  
High Speed ◽  
Degree Of Freedom ◽  
The Real ◽  
Six Degree Of Freedom

Many of accurate inertial guided missilc systems need to use more complex mathematical calculations and require a high speed processing to ensure the real-time opreation. This will give rise to the need of developing an effcint

scholarly journals Review of Linked Array Instruments

1989 ◽  
Vol 8 ◽  
pp. 551-552
Author(s):  
R.D. Ekers
Keyword(s):  
High Resolution ◽  
Real Time ◽  
Angular Resolution ◽  
Research Tool ◽  
Aperture Synthesis ◽  
High Angular Resolution ◽  
Radio Telescopes ◽  
Astronomical Research ◽  
Full Operation ◽  
New Facilities

At cm wavelengths aperture synthesis radio-telescopes (arrays of linked antennas which synthesize an image of the sky with high angular resolution) are now becoming the dominant astronomical research tool. Major new facilities such as the VLA are in full operation, others such as the Australia Telescope are nearing completion and a number of telescopes designed to form images in real time have been converted to operate in the aperture synthesis mode (e.g. MOST, Bologna Cross). See Napier et al. (1983) for a review of modern synthesis telescopes. The high resolution, sensitivity and freedom from confusion have led the aperture synthesis telescopes into very diverse astronomical applications.

scholarly journals A Synthetic Algorithm for Tracking a Moving Object in a Multiple-Dynamic Obstacles Environment Based on Kinematically Planar Redundant Manipulators

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Hongzhe Jin ◽  
Hui Zhang ◽  
Zhangxing Liu ◽  
Decai Yang ◽  
Dongyang Bie ◽  
...  
Keyword(s):  
Real Time ◽  
Null Space ◽  
Inverse Kinematic ◽  
Moving Object ◽  
Redundant Manipulators ◽  
Joint Angles ◽  
The Real ◽  
Time Path ◽  
Planar Manipulators ◽  
Spline Filter

This paper presents a synthetic algorithm for tracking a moving object in a multiple-dynamic obstacles environment based on kinematically planar manipulators. By observing the motions of the object and obstacles, Spline filter associated with polynomial fitting is utilized to predict their moving paths for a period of time in the future. Several feasible paths for the manipulator in Cartesian space can be planned according to the predicted moving paths and the defined feasibility criterion. The shortest one among these feasible paths is selected as the optimized path. Then the real-time path along the optimized path is planned for the manipulator to track the moving object in real-time. To improve the convergence rate of tracking, a virtual controller based on PD controller is designed to adaptively adjust the real-time path. In the process of tracking, the null space of inverse kinematic and the local rotation coordinate method (LRCM) are utilized for the arms and the end-effector to avoid obstacles, respectively. Finally, the moving object in a multiple-dynamic obstacles environment is thus tracked via real-time updating the joint angles of manipulator according to the iterative method. Simulation results show that the proposed algorithm is feasible to track a moving object in a multiple-dynamic obstacles environment.

A Real-Time Hard X-Ray Tomographic System Designed for HL-2A Fast Electron Bremsstrahlung Radiation

2020 ◽  
Author(s):  
Chen Yuan ◽  
Jun Wu
Keyword(s):  
Real Time ◽  
Fast Electron ◽  
High Speed ◽  
Lower Hybrid ◽  
Processing Unit ◽  
Bremsstrahlung Radiation ◽  
X Ray ◽  
The Real ◽  
Electron Bremsstrahlung ◽  
Plasma State

Abstract A real-time hard X-ray (HXR) tomographic system is designed for HL-2A tokamak, which is dedicated to the real-time tomography of fast electron bremsstrahlung radiation during the lower hybrid (LH) driven mode within the energy range of 20keV to 200keV. This system has realized the investigation of HXR energy from 12 different chords on the equatorial plane of the reaction region. The spatial and temporal resolutions of the system are 2cm and 10ms, separately. HXR detection is accomplished by a self-designed detector array, with a structure of 12 arc arranged cadmium telluride (CdTe) semiconductors and their corresponding collimators. The real-time HXR acquisition and processing is achieved by the main electronic system, which is comprised of a high speed analog-to-digital module and a high performance signal processing unit. Due to high HXR flux and the real-time demand in measurement, the HXR tomography is accomplished by several customized digital processing algorithms based on FPGA logic resources, such as the digital real-time spectrum measurement, the trapezoidal shaper, the pile up filter, and the baseline restorer, etc. This system has been proved to be qualified as a dependable platform of fast electron bremsstrahlung radiation research during LH mode on HL-2A, which provides indispensable parameters for plasma state during fusion reaction.

Near Infrared High Angular Resolution Observations of Stars and Circumstellar Regions by the Technique of Lunar Occultations

1994 ◽  
Vol 158 ◽  
pp. 376-378
Author(s):  
T. Chandrasekhar ◽  
N. M. Ashok ◽  
Sam Ragland
Keyword(s):  
High Speed ◽  
Near Infrared ◽  
Angular Resolution ◽  
Infrared Region ◽  
High Angular Resolution ◽  
Filter Bandwidth ◽  
One Dimensional ◽  
Near Infrared Region ◽  
System Frequency ◽  
Source Structure

A program of High Angular Resolution observations of stars and their circumstellar regions using the technique of lunar occultations has been initiated at the 1.2 m telescope at Gurushikhar (24°39′ N, 72°47′ E), India. A liquid nitrogen cooled InSb detector based high speed Infrared photometer with millisecond data acquisition capabilities has been developed for the near Infrared region (1–5 μm) and eight occultations have been successfully observed in the K band (2.2 μm). The sources are (IRC No. -10578, +10013, +20034, +30094, +20190, +20200, +20073 and +00198. The diffraction pattern is clearly seen in all the observations. A convolution analysis involving the system frequency response, filter bandwidth and one dimensional source structure has been carried out to fit the data. System capability has been determined to be ~ 6 milliarcseconds.

scholarly journals RT-SAD: Real-Time Sketch-Based Adaptive DDoS Detection for ISP Network

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Haibin Shi ◽  
Guang Cheng ◽  
Ying Hu ◽  
Fuzhou Wang ◽  
Haoxuan Ding
Keyword(s):  
Real Time ◽  
High Speed ◽  
Attack Detection ◽  
Detection Accuracy ◽  
Network Environment ◽  
The Real ◽  
Feature Extraction Method ◽  
Ddos Attack ◽  
High Speed Network ◽  
Ddos Attack Detection

With the great changes in network scale and network topology, the difficulty of DDoS attack detection increases significantly. Most of the methods proposed in the past rarely considered the real-time, adaptive ability, and other practical issues in the real-world network attack detection environment. In this paper, we proposed a real-time adaptive DDoS attack detection method RT-SAD, based on the response to the external network when attacked. We designed a feature extraction method based on sketch and an adaptive updating algorithm, which makes the method suitable for the high-speed network environment. Experiment results show that our method can detect DDoS attacks using sampled Netflowunder high-speed network environment, with good real-time performance, low resource consumption, and high detection accuracy.

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