DOI: 10.17586/2226-1494-2018-18-1-32-42


SMITH SCHEME APPLICATION IN THE SERVO SYSTEM WITH DELAY IN THE MAIN FEEDBACK

S. V. Bystrov, N. A. Vunder, A. S. Pavlov, M. M. Sinetova, A. V. Ushakov


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For citation: Bystrov S.V., Vunder N.A., Pavlov A.S., Sinetova M.M., Ushakov A.V. Smith scheme application in the servo system with delay in the main feedback. Scientific and Technical Journal of Information Technologies, Mechanics and Optics, 2018, vol. 18, no. 1, pp. 32–42 (in Russian). doi: 10.17586/2226-1494-2018-18-1-32-42

Abstract
 Subject of Research.The subject of the study is the system situation that arises when a continuous plant is included in the system, the main feedback in which contains the link of pure delay. It is shown that for this system situation it is advisable to design a control device for continuous plant in the form of a consecutive compensator. It is found that if the consecutive compensator is included in the structure of the system according to the Smith scheme, then the transfer function of the input-output ratio of such system will not contain the transfer function of the pure delay link neither in the numerator, nor in the denominator, therefore the delay in the main feedback does not affect the system behavior. This property of the system with a consecutive compensator included in the Smith scheme enables the developer to use an algorithm of its synthesis created for plant control systems without delay. Method. The algorithmic basis is based on the use of the Mason method of non-tangential circuits for the transformation of signal structures and the procedure for the synthesis of a consecutive compensator, as a device for controlling continuous plants without delay. The method is based on the properties of typical polynomial models. Main Results. The developer of continuous systems with main feedback with delay obtains a simple algorithm for the synthesis of a consecutive compensator included in the Smith scheme, which completely excludes the effect of the pure delay link on the system behavior. Practical Relevance. The obtained results are of practical value for cases when a plant is included in the system with main feedback containing a pure delay. This is especially important for real technological processes. Practical application of the obtained results is illustrated by computer experiment.

Keywords: continuous plant, servo system, consecutive compensator, pure delay link in the main feedback, Smith scheme, Mason rule, consecutive compensator synthesis algorithm

Acknowledgements. This work was supported by the Government of the Russian Federation, Grant 074-U01; the Ministry of Education and Science of the Russian Federation, Project 14.Z50.31.0031; the Russian Federation President Grant No.14.Y31.16.9281-НШ.

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