Robust Control of Robot Manipulator based on QFT and H∞

Robust controllers have been developed by both control techniques QFT and H∞ applied in the waist, shoulder and elbow of a manipulator of 6 degrees of freedom. The design is based on the identification of a linear model of the robot dynamics which represents the non-linearity of the system using parametric uncertainty. QFT control methodology is used to tune the robust PID-controller and pre-filters of the system, and H∞ controllers are obtained by designing the weighting functions and using the MATLAB hinfopt tool. Finally the performance of robust controllers is compared designed based on the calculation and analysis of some behavioral indices.

Reliable Centralized Control of PMSM

In this paper, we introduce the development methodology of a reliable centralized control applied to a synchronous permanent magnet machine. The proposed system is nonlinear, we linearize around a point of application. The resulting model will then be used to reproduce the dynamic behavior of the machine for a reliable control. The controller is based on the standard h infinite to increase performance, reduce measurement noise, and to tolerate the outage of certain sensors. To illustrate the results, we made a comparison between a standard state feedback control and reliable h infinite robust control. The simulation results shows, that the system in case of technical placements poles loses classic performance in the presence of an outage, that the reliable centralized robust control remain satisfactory performance even in the presence of outage.

Ascertaining Important Features of the JAPROSIM Simulation Library

This paper describes important features of JAPROSIM, a free and open source simulation library implemented in Java programming language. It provides a framework for building discrete event simulation models. The process interaction world view adopted by JAPROSIM is discussed. We present the architecture and major components of the simulation library. In order to ascertain important features of JAPROSIM, examples are given. Further motivations are discussed and suggestions for improving our work are given.

A Model for Anomaly Detection Using the Metaheuristic Methods

Today detection of new threats has become a need for secured communication to provide complete data confidentiality, integrity and availability. Design and development of such an intrusion detection system in the communication world, should not only be new, accurate and fast but also effective in an environment encompassing the surrounding network. In this paper, a new approach is proposed for network anomaly detection by combining neural network and clustering algorithms. We propose a modified Self Organizing Map algorithm which initially starts with null network and grows with the original data space as initial weight vector, updating neighborhood rules and learning rate dynamically in order to overcome the fixed architecture and random weight vector assignment of simple SOM. New nodes are created using distance threshold parameter and their neighborhood is identified using connection strength and its learning rule and the weight vector updating is carried out for neighborhood nodes. The Fuzzy k-means clustering algorithm is employed for grouping similar nodes of Modified SOM into k clusters using similarity measures. Performance of the new approach is evaluated with standard bench mark dataset. The new approach is evaluated using performance metrics such as detection rate and false alarm rate. The result is compared with other individual neural network methods, which shows considerable increase in the detection rate and 1.5% false alarm rate.

A Graph Retrieval Architecture and System for Online Sign Language Dictionary- with an application to Taiwanese Sign Language

Emerging applications for an online sign language dictionary require that retrieval systems retrieve a target vocabulary through visual symbols. However, when people encounter an unknown vocabulary in sign language during communication, they require the online dictionary to retrieve the vocabulary with higher recall-rate and smaller-sized graph through a mobile device. Still, three situations show that the current online dictionary needs an extension. First, previous works lack of retrieving the target graph of a vocabulary through its complete visual symbol-portfolio. Secondly, they often respond a large number of possible images; however, their precisions and recall rates remain very low. Thirdly, previous works of sign language gloves can convert the visual symbols into the graphic features, but only part of the symbols, ignoring the symbols of expression and relative direction. Therefore, the aim of this study is, based on Taiwanese Sign Language, to design a new graph retrieval architecture for sign-language (GRAS), and to implement a new graph retrieval system for sign-language (GRSS) based on this architecture. Finally, we invite users to evaluate GRSS. The experimental results show that GRSS gets convincing performance. And, GRSS adopting RDF technology can improve the performance of GRSS without adopting RDF technology.

Signal Model and Parameter Estimation for Colocated Mimo Radar

In this paper, we consider the signal model and parameter estimation for multiple-input multiple-output (MIMO) radar with colocated antennas on stationary platforms. Considering internal clutter motion, a closed form of the covariance matrix of the clutter signal is derived. Based on the proposed closed form and low rank property of the clutter covariance matrix and by using the singular value decomposition, we have proposed a subspace model for the clutter signal. Following the proposed signal model, we have provided maximum likelihood (ML) estimation for its unknown parameters. Finally, the application of the proposed ML estimation in space time adaptive processing (STAP) is investigated in simulation results. Our ML estimation needs no secondary training data and it can be used in scenarios with nonhomogeneous clutter in range.

An Innovative Security Screening Architecture for Detecting Illicit Goods and Threats

Every year, millions of letters/parcels containing illicit goods are detected by customs authorities, which use traditional security screening equipment. However this equipment cannot detect all kinds of illicit goods and the detection procedure heavily depends on the attention of the customs officer. In order to achieve sufficiently fast intelligent screening of the large volumes of letters/parcels and detect all common kinds of threats, this paper proposes a highly innovative architecture well-beyond the state-of–art. In particular the proposed architecture monitors every letter/parcel by incorporating: (a) terahertz/X-ray sensors, (b) chemical, biological, radiological and nuclear (CBNR) sensors, (c) artificial robot-noses for narcotics, explosives etc., (d) magnetometers for weapons, firearms, banknotes etc., (e) acoustic sensors for liquids/gases/solids, (f) weight/pressure sensors to measure weight distribution, size and shape. Sensory information can be: (a) used to create a “Spectral Signatures Dictionary of Illicit Goods and Threats”, (b) fused to segment/isolate illicit goods and (c) visualized in the form of annotated high-resolution tensor-structured (3D/4D) multisensory image data. The proposed solution also gathers available information for the sender/recipient from various resources, while it also analyzes data from the dark web. All information is forwarded to an AI-based knowledge infrastructure.

Pid Controller Design for Multiple Time Delays System

This paper presents an approach of stabilization and control of time invariant linear system of an arbitrary order that include several time delays. In this work, the stability is ensured by PI, PD and PID controller. The method is analytical and needs the knowledge of transfer function parameters of the plant. It permits to find stability region by the determination of p K , i K and d K gains.

Development of a System for Measurement on Asymmetric Sitting Posture

Sitting posture measurement system using the unstable board with accelerometer was developed. And, postural balance was assessed to determine the effect of asymmetry on sitting posture between patients with pelvic asymmetry and healthy subjects. 10 subjects (pelvic asymmetry patients:5, healthy controls:5) were participated in this study. We performed experiment under static and dynamic sitting condition. Angular variation in the anterior-posterior and left-right direction was measured in both two conditions. Also, intra class correlation coefficient was used to evaluate the reliability of the system. The value of angle of pelvic asymmetry patients was more tilted significantly to the left side than right side during static and dynamic sitting. The reliability of the system was excellent. This paper suggested that a system for measurement on asymmetric sitting posture can be utilized to provide useful information about patients with pelvic asymmetry in rehabilitation medicine. Furthermore, results from this study can be used to develop the new clinical quantitative measurement system.

Reconstruction of High-Resolution Computed Tomography Image in Sinogram Space

An important part of any computed tomography (CT) system is the reconstruction method, which transforms the measured data into images. Reconstruction methods for CT can be either analytical or iterative. The analytical methods can be exact, by exact projector inversion, or non-exact based on Back projection (BP). The BP methods are attractive because of thier simplicity and low computational cost. But they produce suboptimal images with respect to artifacts, resolution, and noise. This paper deals with improve of the image quality of BP by using super-resolution technique. Super-resolution can be beneficial in improving the image quality of many medical imaging systems without the need for significant hardware alternation. In this paper, we propose to reconstruct a high-resolution image from the measured signals in Sinogram space instead of reconstructing low-resolution images and then post-process these images to get higher resolution image.