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Article
Publication date: 1 January 2006

N. Mahalik, C. Xie, J. Pu and P.R. Moore

This paper presents work on design and development of a software platform in terms of virtual distributed control system (DCS) for the design of machine control systems. A…

Abstract

Purpose

This paper presents work on design and development of a software platform in terms of virtual distributed control system (DCS) for the design of machine control systems. A component‐based framework has been adopted within the design avenue, due to the fact that machines or mechatronic systems are built from components: objects as in software engineering. Since machine control systems are distributed conformant, the main focus is given on DCS‐based approach. DCS inherits local intelligence to be incorporated at the field level (sensor and actuator level), unlike its centralised counterpart. The developed platform has been validated through a case study. The virtual platform can be useful for many kinds of event driven target platforms such as assembly lines, conveyor‐based material handling systems, production cells, and so on.

Design/methodology/approach

Components‐based approach virtual design and validation method computer assisted design.

Findings

Specification requirements for virtual design of mechatronic systems.

Originality/value

Prototype tool/approach with a case study example.

Details

Assembly Automation, vol. 26 no. 1
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 1 September 1999

A. Bazezew, J.C. Bruch and J.M. Sloss

Distributed control is an effective method for controlling and suppressing excessive vibrations of continuous systems. Optimal distributed control for a plate problem is…

Abstract

Distributed control is an effective method for controlling and suppressing excessive vibrations of continuous systems. Optimal distributed control for a plate problem is solved utilizing a maximum principle after the introduction of a quadratic index of performance in terms of displacement, velocity and a control force as well as an adjoint variable. The problem is reduced to solving a system of partial differential equations for the state variable and the adjoint variable subjected to boundary, initial and terminal conditions. A numerical algorithm is presented to solve the optimal distributed control problem in the space‐time domain which reduces the computational effort required to solve the initial‐terminal‐boundary value problem. Results obtained for a simply supported, rectangular, thin plate are also presented.

Details

Engineering Computations, vol. 16 no. 6
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 3 April 2009

U.M. Mbanaso, G.S. Cooper, David Chadwick and Anne Anderson

This paper aims to describe a bilateral symmetric approach to authorization, privacy protection and obligation enforcement in distributed transactions. The authors…

Abstract

Purpose

This paper aims to describe a bilateral symmetric approach to authorization, privacy protection and obligation enforcement in distributed transactions. The authors introduce the concept of the obligation of trust (OoT) protocol as a privacy assurance and authorization mechanism that is built upon the XACML standard. The OoT allows two communicating parties to dynamically exchange their privacy and authorization requirements and capabilities, which the authors term a notification of obligation (NoB), as well as their commitments to fulfilling each other's requirements, which the authors term signed acceptance of obligations (SAO). The authors seek to describe some applicability of these concepts and to show how they can be integrated into distributed authorization systems for stricter privacy and confidentiality control.

Design/methodology/approach

Existing access control and privacy protection systems are typically unilateral and provider‐centric, in that the enterprise service provider assigns the access rights, makes the access control decisions, and determines the privacy policy. There is no negotiation between the client and the service provider about which access control or privacy policy to use. The authors adopt a symmetric, more user‐centric approach to privacy protection and authorization, which treats the client and service provider as peers, in which both can stipulate their requirements and capabilities, and hence negotiate terms which are equally acceptable to both parties.

Findings

The authors demonstrate how the obligation of trust protocol can be used in a number of different scenarios to improve upon the mechanisms that are currently available today.

Practical implications

This approach will serve to increase trust in distributed transactions since each communicating party receives a difficult to repudiate digitally signed acceptance of obligations, in a standard language (XACML), which can be automatically enforced by their respective computing machinery.

Originality/value

The paper adds to current research in trust negotiation, privacy protection and authorization by combining all three together into one set of standardized protocols. Furthermore, by providing hard to repudiate signed acceptance of obligations messages, this strengthens the legal case of the injured party should a dispute arise.

Details

Internet Research, vol. 19 no. 2
Type: Research Article
ISSN: 1066-2243

Keywords

Article
Publication date: 23 January 2009

Erol Uzal and Banu Korbahti

The purpose of this paper is to analyse analytically a control scheme in which the resonance frequencies of a rectangular plate is modified by applying a discrete lateral…

Abstract

Purpose

The purpose of this paper is to analyse analytically a control scheme in which the resonance frequencies of a rectangular plate is modified by applying a discrete lateral force proportional to the displacement of the plate measured at a single point.

Design/methodology/approach

An isotropic, elastic, rectangular, thin plate which is simply supported along all sides is actuated at point (x2, y2) by applying a force, and the displacement is measured at (x1, y1).

Findings

The main outcome is the full analytical solution for the controlled eigenfrequencies and mode shapes which allows a detailed study of the efficiency of the control method proposed.

Originality/value

The present study was made in the form of an exact analytical solution and demonstrates that it is possible to affect the eigenfrequencies and mode shapes of a plate by measuring the displacement and applying a pressure at discrete points on the plate.

Details

Aircraft Engineering and Aerospace Technology, vol. 81 no. 2
Type: Research Article
ISSN: 0002-2667

Keywords

Article
Publication date: 15 June 2010

Yongzhong Huang and Yan Feng

The purpose of this paper is to investigate the Lp‐maximal regularity for the abstract incomplete second order problem.

102

Abstract

Purpose

The purpose of this paper is to investigate the Lp‐maximal regularity for the abstract incomplete second order problem.

Design/methodology/approach

First, the paper gives the definition of the Lp‐maximal regularity for incomplete second‐order Cauchy problems and lists their basic properties based on Chill and Srivastava's recent work for completing second order problem. Second, the paper establishes its characterization by means of Fourier multiplier and the operator‐sum theorem. Finally, it considers an application to quasilinear systems by the regularity and linearization techniques.

Findings

Two criteria of Lp‐maximal regularity are obtained, and the existence of the local solution for the second order quasilinear problem is given. In addition, the connection on maximal regularity between second order problems with initial values and that with periodic problems is investigated. A perturbation result is given.

Originality/value

The maximal regularity is an important tool in the theory of non‐linear differential equations. The results obtained in this paper are universal because the operator is not necessarily the generator of a cosine operator function. Using this unifying approach it is possible to clarify the Lp‐maximal regularity and the existence of the solution for some systems described by partial differential equations, such as wave equations.

Details

Kybernetes, vol. 39 no. 6
Type: Research Article
ISSN: 0368-492X

Keywords

Article
Publication date: 31 May 2013

Chao Guo, Huai‐Ning Wu, Biao Luo and Lei Guo

The air‐breathing hypersonic vehicle (AHV) includes intricate inherent coupling between the propulsion system and the airframe dynamics, which results in an intractable…

Abstract

Purpose

The air‐breathing hypersonic vehicle (AHV) includes intricate inherent coupling between the propulsion system and the airframe dynamics, which results in an intractable nonlinear system for the controller design. The purpose of this paper is to propose an H∞ control method for AHV based on the online simultaneous policy update algorithm (SPUA).

Design/methodology/approach

Initially, the H∞ state feedback control problem of the AHV is converted to the problem of solving the Hamilton‐Jacobi‐Isaacs (HJI) equation, which is notoriously difficult to solve both numerically and analytically. To overcome this difficulty, the online SPUA is introduced to solve the HJI equation without requiring the accurate knowledge of the internal system dynamics. Subsequently, the online SPUA is implemented on the basis of an actor‐critic structure, in which neural network (NN) is employed for approximating the cost function and a least‐square method is used to calculate the NN weight parameters.

Findings

Simulation study on the AHV demonstrates the effectiveness of the proposed H∞ control method.

Originality/value

The paper presents an interesting method for the H∞ state feedback control design problem of the AHV based on online SPUA.

Article
Publication date: 1 February 2004

Guangxing Tan and Jian Pan

This paper studies the stability properties of a class of nonlinear output‐feedback control system. By using a control transform and constructing Liapunov function, the…

307

Abstract

This paper studies the stability properties of a class of nonlinear output‐feedback control system. By using a control transform and constructing Liapunov function, the sufficient conditions of the asymptotic stability for the nonlinear control system are presented. The result in this paper includes some existing results.

Details

Kybernetes, vol. 33 no. 2
Type: Research Article
ISSN: 0368-492X

Keywords

Article
Publication date: 7 August 2019

Zhengyu Huang, Lingyu Chen, Lianchao Zhang, Shixun Fan and Dapeng Fan

This paper aims to analyze the key factors influencing the synchronization performance of distributed motion control system and to improve the synchronization performance…

Abstract

Purpose

This paper aims to analyze the key factors influencing the synchronization performance of distributed motion control system and to improve the synchronization performance for peripherals control of this system.

Design/methodology/approach

This paper deals with the software synchronization problems of distributed motion control system based on real-time Ethernet. First, combined with communication and control tasks, the key factors affecting synchronization performance of system are analyzed. Then, aiming at key factors and considering the synchronization of system bus, protocol conversion and task scheduling, a software synchronization method based on CANopen protocol and real-time Ethernet is proposed. Finally, the feasibility of this method is verified by establishing distributed motion control system and testing the synchronization performance of terminal control signals of slaves.

Findings

Based on this method, the results show that the synchronization accuracy for peripherals control of all slaves could be about 100 ns.

Practical implications

This research provides high-precision synchronization method, which could lay a foundation for the application of distributed motion control system in the field of assembly automation, such as multi-axis assembly robots control.

Originality/value

In distributed motion control system, many factors affect the synchronization performance. At present, there is no synchronization method that could comprehensively consider these factors. This paper not only analyzes the key factors influencing the synchronization performance of system but also proposes a synchronization method. Therefore, the method proposed in this paper has certain theoretical value and engineering significance.

Details

Assembly Automation, vol. 39 no. 5
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 20 March 2019

Yanchao Sun, Liangliang Chen and Hongde Qin

This paper aims to investigate the distributed coordinated fuzzy tracking problems for multiple mechanical systems with nonlinear model uncertainties under a directed…

Abstract

Purpose

This paper aims to investigate the distributed coordinated fuzzy tracking problems for multiple mechanical systems with nonlinear model uncertainties under a directed communication topology.

Design/methodology/approach

The dynamic leader case is considered while only a subset of the follower mechanical systems can obtain the leader information. First, this paper approximates the system uncertainties with finite fuzzy rules and proposes a distributed adaptive tracking control scheme. Then, this paper makes a detailed classification of the system uncertainties and uses different fuzzy systems to approximate different kinds of uncertainties. Further, an improved distributed tracking strategy is proposed. Closed-loop systems are investigated using graph theory and Lyapunov theory. Numerical simulations are performed to verify the effectiveness of the proposed methods.

Findings

Based on fuzzy control and adaptive control theories, the desired distributed coordinated tracking control strategies for multiple uncertain mechanical systems are developed.

Originality/value

Compared with most existing literature, the proposed distributed tracking algorithms use fuzzy control and adaptive control techniques to cope with system nonlinear uncertainties of multiple mechanical systems. Moreover, the improved control strategy not only reduces fuzzy rules but also has higher control accuracy.

Details

Assembly Automation, vol. 39 no. 1
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 22 November 2010

Hen‐I Yang, Chao Chen, Bessam Abdulrazak and Sumi Helal

A decade and a half after the debut of pervasive computing, a large number of prototypes, applications, and interaction interfaces have emerged. However, there is a lack…

Abstract

Purpose

A decade and a half after the debut of pervasive computing, a large number of prototypes, applications, and interaction interfaces have emerged. However, there is a lack of consensus about the best approaches to create such systems or how to evaluate them. To address these issues, this paper aims to develop a performance evaluation framework for pervasive computing systems.

Design/methodology/approach

Based on the authors' experience in the Gator Tech Smart House – an assistive environment for the elderly, they established a reference scenario that was used to guide the analysis of the large number of systems they studied. An extensive survey of the literature was conducted, and through a thorough analysis, the authors derived and arrived at a broad taxonomy that could form a basic framework for evaluating existing and future pervasive computing systems.

Findings

A taxonomy of pervasive systems is instrumental to their successful evaluation and assessment. The process of creating such taxonomy is cumbersome, and as pervasive systems evolve with new technological advances, such taxonomy is bound to change by way of refinement or extension. This paper found that a taxonomy for something so broad as pervasive systems is very complex. It overcomes the complexity by focusing the classifications on key aspects of pervasive systems, decided purely empirically and based on the authors own experience in a real‐life, large‐scale pervasive system project.

Originality/value

There are currently no methods or frameworks for comparing, classifying, or evaluating pervasive systems. The paper establishes a taxonomy – a first step toward a larger evaluation methodology. It also provides a wealth of information, derived from a survey of a broad collection of pervasive systems.

Details

International Journal of Pervasive Computing and Communications, vol. 6 no. 4
Type: Research Article
ISSN: 1742-7371

Keywords

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