A Design Method for Modified Smith Predictors for Non-Minimum-Phase Time-Delay Plants with Feedback Connected Multiple Time-Delays

Author(s):  
Kou Yamada ◽  
Yoshinori Ando ◽  
Hideharu Yamamoto ◽  
Iwanori Murakami
2010 ◽  
Vol 36 ◽  
pp. 253-262 ◽  
Author(s):  
Iwanori Murakami ◽  
Nghia Thi Mai ◽  
Kou Yamada ◽  
Takaaki Hagiwara ◽  
Yoshinori Ando ◽  
...  

In this paper, we examine a design method for modified Smith predictors for non-minimum-phase time-delay plants with multiple feedback-connected time-delays. The Smith predictor is proposed by Smith to overcome time-delay and known as an effective time-delay compensator for a plant with large time-delay. The Smith predictor by Smith cannot be used for plants having an integral mode, because a step disturbance will result in a steady state error. Several papers considered the problem to design modified Smith predictors for unstable plants. However, no paper examines a design method for modified Smith predictors for non-minimum-phase time-delay plants with multiple feedback-connected time-delays. In this paper, we examine a design method for modified Smith predictors for non-minimum-phase time-delay plants with multiple feedback-connected time-delays.


Author(s):  
Kou Yamada ◽  
Nobuaki Matsushima

In this paper, we examine a design method for a modified Smith predictor for minimum-phase timedelay plants. The modified Smith predictor is well known as an effective time-delay compensator for a plant with large time delays, and several papers on the modified Smith predictor have been published. However, the parameterization of all stabilizing modified Smith predictors has not been obtained. If this can be obtained, we can express existing proposals for modified Smith predictors in a uniform manner, and the modified Smith predictor can be designed systematically. The purpose of this paper is to propose the parameterization of all stabilizing modified Smith predictors for minimum-phase time-delay plants. The control characteristics of the control system using the parameterization of all stabilizing modified Smith predictors are also given. Finally, numerical examples for stable plants and unstable plants are illustrated to show the effectiveness of the proposed parameterization of all stabilizing modified Smith predictors.


Author(s):  
Joseph D. Hart ◽  
Laurent Larger ◽  
Thomas E. Murphy ◽  
Rajarshi Roy

We present a systematic approach to reveal the correspondence between time delay dynamics and networks of coupled oscillators. After early demonstrations of the usefulness of spatio-temporal representations of time-delay system dynamics, extensive research on optoelectronic feedback loops has revealed their immense potential for realizing complex system dynamics such as chimeras in rings of coupled oscillators and applications to reservoir computing. Delayed dynamical systems have been enriched in recent years through the application of digital signal processing techniques. Very recently, we have showed that one can significantly extend the capabilities and implement networks with arbitrary topologies through the use of field programmable gate arrays. This architecture allows the design of appropriate filters and multiple time delays, and greatly extends the possibilities for exploring synchronization patterns in arbitrary network topologies. This has enabled us to explore complex dynamics on networks with nodes that can be perfectly identical, introduce parameter heterogeneities and multiple time delays, as well as change network topologies to control the formation and evolution of patterns of synchrony. This article is part of the theme issue ‘Nonlinear dynamics of delay systems’.


2021 ◽  
Vol 31 (15) ◽  
Author(s):  
Yuanhong Bi ◽  
Yanan Li ◽  
Jianmin Hou ◽  
Quansheng Liu

p53 dynamics plays an important role in determining cell arrest or apoptosis upon DNA damage response. In this paper, based on a p53 gene regulatory network composed of its core regulator ATM, Mdm2 and Wip1, the effect of multiple time delays in transcription and translation of Mdm2 and Wip1 gene expression on p53 dynamics are investigated through theoretical and numerical analyses. The stability of the positive equilibrium point and the existence of Hopf bifurcation are demonstrated through analyzing the associated characteristic equation of the corresponding linearized system in five cases. Detailed numerical simulations and bifurcation analyses are performed to support the theoretical results. The results show that with the increase of a time delay, the positive equilibrium point becomes unstable, and the p53 dynamics presents an oscillating state. These results reveal that time delay has a significant impact on p53 dynamics and may provide a useful insight into developing anti-cancer therapy.


2018 ◽  
Vol 65 ◽  
pp. 84-90 ◽  
Author(s):  
Xiaoli Luan ◽  
Qiang Chen ◽  
Pedro Albertos ◽  
Fei Liu

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Bo Li ◽  
Xiaobing Zhou ◽  
Yun Wang

Time delay is a frequently encountered phenomenon in some practical engineering systems and introducing time delay into a system can enrich its dynamic characteristics. There has been a plenty of interesting results on fractional-order chaotic systems or integer-order delayed chaotic systems, but the problem of synchronization of fractional-order chaotic systems with time delays is in the primary stage. Combination synchronization of three different fractional-order delayed chaotic systems is investigated in this paper. It is an extension of combination synchronization of delayed chaotic systems or combination synchronization of fractional-order chaotic systems. With the help of stability theory of linear fractional-order systems with multiple time delays, we design controllers to achieve combination synchronization of three different fractional-order delayed chaotic systems. In addition, numerical simulations have been performed to demonstrate and verify the theoretical analysis.


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