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Article

C. McCORKELL and B.H. SWANICK

A structurally constrained discrete state space model is employed as the basis in the development of an identification and control procedure. System excitation is…

Abstract

A structurally constrained discrete state space model is employed as the basis in the development of an identification and control procedure. System excitation is conditioned in accordance with a restricted minimization of a composite cost functional embodying a compromise legitimizing simultaneous identification and control. Alternative scalar measures of the system identified parametric transition matrices are combined with a state quadratic control measure in the composite cost, and an investigation of the effect of a scalar weighting in the functional (offsetting identification with control) considered. Tabular and graphical results are presented covering the likely range of the proposed systems applicability.

Details

Kybernetes, vol. 4 no. 2
Type: Research Article
ISSN: 0368-492X

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Article

Bahram Tarvirdizadeh, Esmaeel Khanmirza, Morteza Ebrahimi, Ahmad Kalhor and Shidvash Vakilipour

The purpose of this paper is to propose an efficient and straightforward approach for system identification of a rotating single link flexible manipulator (RSLFM). Also…

Abstract

Purpose

The purpose of this paper is to propose an efficient and straightforward approach for system identification of a rotating single link flexible manipulator (RSLFM). Also, the achieved results are experimentally validated through identification procedure.

Design/methodology/approach

The proposed system identification approach is applied to a RSLFM with a tip mass. At first, the dynamic model of the system is derived using Lagrange method. Then, an efficient method is developed for identification of such a system. This method facilitates the nonlinear complicated identification problem of the RSLFM to a simplified root finding problem.

Findings

The main advantage of the developed method is to convert a complicated system identification process to a simple nonlinear equation solution. This approach uses small-size input/output data set and requires a short-time interval of data acquisition, which gives important advantages in lower computational load and lower execution time. The investigated approach is studied on experimental system identification of a single link flexible manipulator. To demonstrate this fact, the developed method is successfully applied in identification of two other mechanical systems; the inverted pendulum on a cart and the ball and beam apparatus.

Originality/value

In this work, the proposed identification approach has been originally applied to a RSLFM and two other mechanical examples. All obtained identification results show the performance and applicability of the developed method clearly. This approach is not restricted in using state space or transfer function. It has significant superiority in comparison with other known approaches including autoregressive with exogenous input (ARX) and Box-Jenkins (BJ).

Details

Engineering Computations, vol. 32 no. 8
Type: Research Article
ISSN: 0264-4401

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Article

Khawaja Shafiq Haider, Aamina Bintul Huda, Akhtar Rasool and Syed Hashim Raza Bukhari

The purpose of this paper is to identify the fault modes of a nonlinear twin-rotor system (TRS) using the subspace technique to facilitate fault identification, diagnosis…

Abstract

Purpose

The purpose of this paper is to identify the fault modes of a nonlinear twin-rotor system (TRS) using the subspace technique to facilitate fault identification, diagnosis and control applications.

Design/methodology/approach

For identification of fault modes, three types of system malfunctions are introduced. First malfunction resembles actuator, second internal system dynamics and third represents sensor malfunction or offset. For each fault scenario, the resulting TRS model is applied with persistently exciting inputs and corresponding outputs are recorded. The collected input–output data are invoked in NS4SID subspace system identification algorithm to obtain the unknown fault model. The identified actuator fault modes of the TRS can be used for fault diagnostics, fault isolation or fault correction applications.

Findings

The identified models obtained through system identification are validated for correctness by comparing the response of the actual model under the fault condition and identified model. The results certify that the identified fault modes correctly resemble the respective fault conditions in the actual system.

Originality/value

The utilization of proposed work for current research emphasized the area of fault detection, diagnosis and correction applications that makes its value significantly. These modes when used for diagnosis purposes allow users to timely get intimated and rectify the performance degradation of the plant before it gets totally malfunctioned. Moreover, the slight performance degradation is also indicated when fault diagnosis is performed.

Details

International Journal of Intelligent Unmanned Systems, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2049-6427

Keywords

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Article

Li‐An Ho, Tsung‐Hsien Kuo and Binshan Lin

The purpose of this study is to propose a conceptual structural equation model to, first, investigate the relationships among knowledge management (KM) system quality…

Abstract

Purpose

The purpose of this study is to propose a conceptual structural equation model to, first, investigate the relationships among knowledge management (KM) system quality, employees' self‐perceived social identification, trust at workplace as well as online knowledge sharing behaviors, and, second, demonstrate the direct and indirect effect of social identification and trust at workplace on online knowledge sharing from the perspective of KM system quality.

Design/methodology/approach

A questionnaire was distributed to 437 full‐time employees (n=437) from three technology companies in Taiwan. These companies have had years of experience in implementing KM systems. Data were analyzed by employing structural equation modeling.

Findings

The results show that: social identification and trust at workplace have a mediating effect on online knowledge sharing within organizations; trust at workplace is the stronger mediator than social identification; social identification has a positive and significant impact on trust at workplace; and there is significant correlation between KM system quality and social identification as well as trust.

Practical implications

Based on these findings, organizations in Taiwan that aim to maximize the effectiveness and efficiency of KM systems should find ways to enhance employees' self‐awareness on social identification and trust in the workplace.

Originality/value

The conceptual model provides useful information for managers to enhance knowledge sharing through the formation of social identification and promotion of trust at workplaces.

Details

Internet Research, vol. 22 no. 1
Type: Research Article
ISSN: 1066-2243

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Article

Yamna Ghoul

An identification scheme to identify interconnected discrete-time (DT) varying systems.

Abstract

Purpose

An identification scheme to identify interconnected discrete-time (DT) varying systems.

Design/methodology/approach

The purpose of this paper is the identification of interconnected discrete time varying systems. The proposed technique permits the division of global system to many subsystems by building a vector observation of each subsystem and then using the gradient method to identify the time-varying parameters of each subsystem. The convergence of the presented algorithm is proven under a given condition.

Findings

The effectiveness of the proposed technique is then shown with application to a simulation example.

Originality/value

In the past decade, there has been a renewed interest in interconnected systems that are multidimensional and composed of similar subsystems, which interact with their closest neighbors. In this context, the concept of parametric identification of interconnected systems becomes relevant, as it considers the estimation problem of such systems. Therefore, the identification of interconnected systems is a challenging problem in which it is crucial to exploit the available knowledge about the interconnection structure. For time-varying systems, the identification problem is much more difficult. To cope with this issue, this paper addresses the identification of DT dynamical models, composed by the interconnection of time-varying systems.

Details

Engineering Computations, vol. 37 no. 3
Type: Research Article
ISSN: 0264-4401

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Article

Yong Xie, Pan Liu and Guoping Cai

The purpose of this paper is to present an on-orbit frequency identification method for spacecraft directly using attitude maneuver data. Natural frequency of flexible…

Abstract

Purpose

The purpose of this paper is to present an on-orbit frequency identification method for spacecraft directly using attitude maneuver data. Natural frequency of flexible solar arrays plays an important role in attitude control design of spacecraft with solar arrays, and its precision will directly affect the accuracy of attitude maneuver. However, when the flexibility of the solar arrays is large, because of air damping, gravity effect etc., the frequency obtained by ground test shows great error compared with the on-orbit real value. One solution to this problem is to conduct on-orbit identification during which proper identification methods are used to obtain the parameters of interest based on the real on-orbit data of spacecraft.

Design/methodology/approach

The observer/Kalman filter identification and eigensystem realization algorithm are used as identification methods, and the attitude maneuver controller is designed using the rigid-body dynamics method.

Findings

Two conclusions are drawn in this paper according to results of numerical simulations. The first one is that the attitude controller based on the rigid-body dynamics method is effective in attitude maneuver of the spacecraft. The second one is that the on-orbit parameter identification can be directly achieved by using attitude maneuver data of spacecraft without adding additional missions.

Practical implications

Based on the methods proposed in this paper, it is convenient to obtain the natural frequencies of the spacecraft using the data of the attitude maneuver, which may greatly reduce the cost of on-orbit identification test.

Originality/value

The way of obtaining natural frequencies based on attitude maneuver data of spacecraft provides high originality and value for practical application.

Details

Aircraft Engineering and Aerospace Technology, vol. 90 no. 1
Type: Research Article
ISSN: 1748-8842

Keywords

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Article

Zhiyu Ni, Yewei Zhang, Xinhui Shen, Shunan Wu and Zhigang Wu

When a manipulator captures an unknown space object, inertia parameters of endpoint payload should be timely obtained to handle possible unexpected parameter variations…

Abstract

Purpose

When a manipulator captures an unknown space object, inertia parameters of endpoint payload should be timely obtained to handle possible unexpected parameter variations and monitor the system’s operating conditions. Therefore, this study aims to present an identification method for estimating the inertia parameter of the payload carried by a flexible two-link space manipulator.

Design/methodology/approach

The original nonlinear dynamics model of the manipulator is linearized at a selected working point. Subsequently, the system modal frequencies with and without payload are determined using the subspace identification algorithm, and the difference of these frequencies is computed. Furthermore, by adjusting the structural configuration of the manipulator, multiple sets of frequency differences are obtained. Therefore, the inertia parameters of the payload, i.e. the mass and the moment of inertia, can be derived from the frequency differences by solving a least-squares problem.

Findings

The proposed method can effectively estimate the payload parameters and has satisfactory identification accuracy.

Practical implications

The approach’s implementation provides a practical reference for determining inertia parameters of an unknown space target in the capture process.

Originality/value

The study proposes a novel method for identifying the inertia parameters of the payload of a flexible two-link space manipulator using the estimated system frequencies.

Details

Aircraft Engineering and Aerospace Technology, vol. 92 no. 6
Type: Research Article
ISSN: 1748-8842

Keywords

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Article

Bartlomiej Guzowski, Roman Gozdur, Mateusz Lakomski and Lukasz Bernacki

The purpose of this paper is to develop identification system for fiber optic connectors in passive distribution cabinets. The system should have alternative power supply…

Abstract

Purpose

The purpose of this paper is to develop identification system for fiber optic connectors in passive distribution cabinets. The system should have alternative power supply and wireless communication unlike the identification systems commercially available, which will make the system fully autonomous.

Design/methodology/approach

Detailed project and realization of real demonstrator of fully autonomous identification system. After the realization of the demonstrator, its optimization was performed.

Findings

It is possible to build fully autonomous identification system which requires 15.6 mJ energy to perform one cycle of identification process. Moreover, it is possible to use the alternative power method to supply this system.

Originality/value

Fully autonomous identification system of fiber optic connectors with alternative power supply and wireless communication.

Details

Circuit World, vol. 43 no. 1
Type: Research Article
ISSN: 0305-6120

Keywords

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Article

Paul Beynon‐Davies

The purpose of this paper is to unpack some of the socio‐technical relationships inherent in contemporary notions of personal identity management. For this purpose it…

Abstract

Purpose

The purpose of this paper is to unpack some of the socio‐technical relationships inherent in contemporary notions of personal identity management. For this purpose it considers the issue of personal identity management in terms of a framework, which distinguishes between the related processes of authentication, identification and enrolment.

Design/methodology/approach

The conceptual model described in this paper is reflected against an important recent case in which issues of personal identity management are being enacted: the introduction of a UK national identity card. Both this issue and case are particularly examined in the light of the growth of e‐Government in the UK.

Findings

The paper relates issues associated with the technical infrastructure of e‐Government with some of the costs and benefits associated with the social infrastructure of e‐Government. This device offers a useful framing for a whole range of issues surrounding individual‐organisation interaction in the Information Society that rely on elements of personal identity management.

Research limitations/implications

In the paper the issue of personal identity management is under‐represented in the Information Systems and Information Management literature. The conceptual approach adopted in the paper is used to identify areas of further research in terms of issues relevant to the technical infrastructure of e‐Government.

Practical implications

The paper identifies a number of personal identity management issues embedded in the technical infrastructure required for effective e‐Government.

Originality/value

This paper raises the importance of personal identity management to the success of the e‐Government agenda. It also links classic information management issues to the issue of personal identity management and identifies the challenges for e‐Government within this.

Details

Journal of Enterprise Information Management, vol. 20 no. 3
Type: Research Article
ISSN: 1741-0398

Keywords

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Article

Ismaila B. Tijani, Rini Akmeliawati, Ari Legowo, Agus Budiyono and Asan G. Abdul Muthalif

The purpose of this paper is to develop a hybrid algorithm using differential evolution (DE) and prediction error modeling (PEM) for identification of small-scale…

Abstract

Purpose

The purpose of this paper is to develop a hybrid algorithm using differential evolution (DE) and prediction error modeling (PEM) for identification of small-scale autonomous helicopter state-space model.

Design/methodology/approach

In this study, flight data were collected and analyzed; MATLAB-based system identification algorithm was developed using DE and PEM; parameterized state-space model parameters were estimated using the developed algorithm and model dynamic analysis.

Findings

The proposed hybrid algorithm improves the performance of the PEM algorithm in the identification of an autonomous helicopter model. It gives better results when compared with conventional PEM algorithm inside MATLAB toolboxes.

Research limitations/implications

This study is applicable to only linearized state-space model.

Practical implications

The identification algorithm is expected to facilitate the required model development for model-based control design for autonomous helicopter development.

Originality/value

This study presents a novel hybrid algorithm for system identification of an autonomous helicopter model.

Details

Aircraft Engineering and Aerospace Technology: An International Journal, vol. 86 no. 5
Type: Research Article
ISSN: 0002-2667

Keywords

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