摘要:

Conic provides a set of tools for building flexible distributed systems for embedded applications such as factory automation, telecommunications, process monitoring and control. The Conic programming language is used to program individual software modules which communicate by naming only local entry and exit ports. This gives configuration independence and allows reuse of the modules in various situations. A separate configuration language is used to specify a system by creating instances of modules and interconnecting exit and entry ports. The configuration language is also used to specify changes which can be performed dynamically without shutting down the complete system. These features of a Conic system provide the flexibility for adapting to changing requirements. The paper describes the Conic programming and configuration languages, as well as the run-time support needed for dynamic configuration. The paper also gives an overview of the Unix-based tools available for building and testing software for distributed target computers. Finally, we discuss experiences of using these tools and future work planned on the project.

DOI:10.1049/ip-d.1987.0014

出版商:IEE    

年代:1987

数据来源: IET

摘要:

The paper describes work performed in collaboration with the British Gas Corporation, in relation to the development of algorithms for monitoring the condition of high-pressure gas pipelines. The practical problem considered is that of reconstructing the pressure profile along a single length of pipe from pressure measurements at the end points and a further measurement at an intermediate point along the pipe. The approach adopted is based on the implementation of a finite-dimensional asymptotic state observer derived from consideration of the distributed-parameter properties of the system. The paper includes the results of a computational study in which the observer was evaluated against experimental data corresponding to an 80 km section of pipe. These results indicate that the dynamic observer is capable of providing an accurate estimate of the pressure profile over a complete 24 h demand cycle.

DOI:10.1049/ip-d.1987.0015

出版商:IEE    

年代:1987

数据来源: IET

摘要:

The identification of a variable linear system with coefficients depending on an assumed measurable parameter is considered. A direct approach leads to a least-squares estimation computed with the input and output sequences filtered through a variable linear filter, to obtain an unbiased estimation.

DOI:10.1049/ip-d.1987.0016

出版商:IEE    

年代:1987

数据来源: IET

摘要:

This paper presents a non-Luré type Lyapunov function for the transient stability analysis of multimachine power systems. A systematic procedure for constructing the Lyapunov function which includes a new term which does not appear in the Luré type function is shown. The procedure is essentially based on the generalised Popov criterion developed by Moore and Anderson. The power system model used in this paper consists of synchronous machines interconnected by a lossless transmission system. It is shown that the conventional Luré type functions and energy functions constructed for this model are regarded as particular cases of the result obtained in this paper. The superiority of the proposed Lyapunov function is illustrated by numerical examples.

DOI:10.1049/ip-d.1987.0017

出版商:IEE    

年代:1987

数据来源: IET

摘要:

A direct approach to the analysis of systems with single, or commensurate delays is presented, and compared with other recently proposed methods. The finite polynomials arising in this direct method are shown to have useful sensitivity properties. Remarks are given concerning systems stable independent of delay.

DOI:10.1049/ip-d.1987.0018

出版商:IEE    

年代:1987

数据来源: IET

摘要:

A direct method, i.e. not involving infinite summations, for the evaluation of TDS cost functionals in closed form is extended to cases involving two or more commensurate delays.

DOI:10.1049/ip-d.1987.0019

出版商:IEE    

年代:1987

数据来源: IET

摘要:

Earlier work on sector bounded nonlinear multivariable systems has provided dynamic performance bounds on system response, via an element-by-elementL∞treatment. However, this approach relies on a stability criterion which is potentially very conservative, since it ignores both frequency dependence and phase interrelationships. In the paper, we useL2vector norms in conjunction with nonsimilarity scaling to retrieve this information, and hence to derive a significantly improved stability condition. By the introduction of exponential weighting, it is then shown that theL2stability result may be used to establish absolute bounds on system performance.

DOI:10.1049/ip-d.1987.0020

出版商:IEE    

年代:1987

数据来源: IET

摘要:

In a recent article, the performance of six established techniques for designing continuous controllers for time-delayed processes was compared with the Zakian's method of inequalities. Based on his simulation results, the author claimed superiority of his approach over the classical methods. Using the same examples, it is shown here that such claims are not fully justified and additional little known techniques of comparable performance are presented.

DOI:10.1049/ip-d.1987.0021

出版商:IEE    

年代:1987

数据来源: IET

摘要:

Coefficient assignment of the characteristic polynomial corresponding to a generalised linear system using state feedback laws is discussed. The equivalence of a method using Sylvester's equation to the methods of Ackermann and Bass-Gura is derived. The single-input case follows directly from the nonpolynomial case, but for multi-input it is demonstrated that a more stringent condition on the controllability matrix is required.

DOI:10.1049/ip-d.1987.0022

出版商:IEE    

年代:1987

数据来源: IET