scholarly journals Stability and Control of Biomolecular Circuits through Structure

2020 ◽  
Author(s):  
Fangzhou Xiao ◽  
Mustafa Khammash ◽  
John C. Doyle
Keyword(s):  
Disturbance Rejection ◽  
Environmental Disturbances ◽  
Analysis And Design ◽  
Stability And Control ◽  
Perfect Adaptation ◽  
Degradation Rates ◽  
Functional Forms ◽  
And Control ◽  
Step Disturbance ◽  
Biological Organisms

AbstractDue to omnipresent uncertainties and environmental disturbances, natural and engineered biological organisms face the challenging control problem of achieving robust performance using unreliable parts. The key to overcoming this challenge rests in identifying structures of biomolecular circuits that are largely invariant despite uncertainties, and building feedback control through such structures. In this work, we develop the tool of log derivatives to capture structures in how the production and degradation rates of molecules depend on concentrations of reactants. We show that log derivatives could establish stability of fixed points based on structure, despite large variations in rates and functional forms of models. Furthermore, we demonstrate how control objectives, such as robust perfect adaptation (i.e. step disturbance rejection), could be implemented through the structures captured. Due to the method’s simplicity, structural properties for analysis and design of biomolecular circuits can often be determined by a glance at the equations.

Design and Analysis of High-Gain Switched-Capacitor-Inductor-Based Inverter for Step-Up DC-AC Conversion

2017 ◽  
Vol 27 (02) ◽  
pp. 1850030 ◽  
Author(s):  
Yuen-Haw Chang ◽  
Yu-Kai Lin
Keyword(s):  
Power Efficiency ◽  
Pulse Width Modulation ◽  
High Gain ◽  
Switched Capacitor ◽  
Analysis And Design ◽  
Stability And Control ◽  
Power Part ◽  
Resonant Inductor ◽  
And Control ◽  
Sinusoidal Pulse Width Modulation

This paper presents the analysis, design and implementation of a closed-loop high-gain switched-capacitor-inductor-based inverter (SCII) by combining a sinusoidal pulse-width-modulation (SPWM) controller and phase generator for realizing the step-up inversion and regulation. The power part is composed of two cascaded sub-circuits from source [Formula: see text] to output voltage [Formula: see text]: (i) SCI booster (one resonant inductor, 4 pumping capacitors and 7 switches regulated by phase generator) and (ii) DC-link inverter (one filter capacitor and 4 switches controlled by SPWM), in order to provide a wide step-up output range of [Formula: see text] as: [Formula: see text] for DC-AC conversion, where [Formula: see text] ([Formula: see text]) is the ratio cycle of charging the inductor (e.g., the maximum of [Formula: see text] reaches 13.8 times voltage of [Formula: see text] while [Formula: see text]). Here, by using the phase generator, the maximum of step-up gain can be regulated for fitting the need of AC load. Further, the SPWM controller is employed to enhance regulation capability for the different amplitude and frequency of output, as well as robustness to loading variation. Some theoretical analysis and design are included: formulation, steady-state analysis, conversion ratio, power efficiency, inductance and capacitance selection, circuit stability and control design. Finally, the performance of SCII is simulated, and verified experimentally on the implemented prototype circuit, and the results are illustrated to show the efficacy of this scheme.

scholarly journals Antithetic Integral Feedback: A new motif for robust perfect adaptation in noisy biomolecular networks

2015 ◽  
Author(s):  
Corentin Briat ◽  
Ankit Gupta ◽  
Mustafa Khammash
Keyword(s):  
Feedback Regulation ◽  
Reaction Rates ◽  
Living Cells ◽  
Regulatory Function ◽  
Regulatory Motif ◽  
Analysis And Design ◽  
Perfect Adaptation ◽  
Integral Feedback ◽  
The Stability ◽  
And Control

Homeostasis is a running theme in biology. Often achieved through feedback regulation strategies, homeostasis allows living cells to control their internal environment as a means for surviving changing and unfavourable environments. While many endogenous homeostatic motifs have been studied in living cells, some other motifs may remain under-explored or even undiscovered. At the same time, known regulatory motifs have been mostly analyzed at the deterministic level, and the effect of noise on their regulatory function has received low attention. Here we lay the foundation for a regulation theory at the molecular level that explicitly takes into account the noisy nature of biochemical reactions and provides novel tools for the analysis and design of robust homeostatic circuits. Using these ideas, we propose a new regulation motif, which we refer to as antithetic integral feedback, and demonstrate its effectiveness as a strategy for generically regulating a wide class of reaction networks. By combining tools from probability and control theory, we show that the proposed motif preserves the stability of the overall network, steers the population of any regulated species to a desired set point, and achieves robust perfect adaptation -- all with low prior knowledge of reaction rates. Moreover, our proposed regulatory motif can be implemented using a very small number of molecules and hence has a negligible metabolic load. Strikingly, the regulatory motif exploits stochastic noise, leading to enhanced regulation in scenarios where noise-free implementations result in dysregulation. Finally, we discuss the possible manifestation of the proposed antithetic integral feedback motif in endogenous biological circuits and its realization in synthetic circuits.

Nonlinear analysis of stability and control for an F-16 configuration

1997 ◽  
Author(s):  
Zhongjun Wang ◽  
Zhidai He ◽  
C. Lan ◽  
Zhongjun Wang ◽  
Zhidai He ◽  
...  
Keyword(s):  
Nonlinear Analysis ◽  
Stability And Control ◽  
Analysis Of Stability ◽  
And Control

Designing Stability and Control Augmentation Systems Using Genetic Algorithms

2009 ◽  
Author(s):  
Ashraf Omran ◽  
Mohamed Elshabasy ◽  
Wael Mokhtar ◽  
Brett Newman ◽  
Mohamed Gharib
Keyword(s):  
Genetic Algorithms ◽  
Stability And Control ◽  
And Control

scholarly journals Method for designing multi-input system identification signals using a compact time-frequency representation

2021 ◽  
Author(s):  
Mathias Stefan Roeser ◽  
Nicolas Fezans
Keyword(s):  
System Identification ◽  
Design Method ◽  
Flight Test ◽  
Compact Representation ◽  
Time Frequency ◽  
Stability And Control ◽  
Frequency Representation ◽  
Aerodynamic Parameters ◽  
Definition Of ◽  
And Control

AbstractA flight test campaign for system identification is a costly and time-consuming task. Models derived from wind tunnel experiments and CFD calculations must be validated and/or updated with flight data to match the real aircraft stability and control characteristics. Classical maneuvers for system identification are mostly one-surface-at-a-time inputs and need to be performed several times at each flight condition. Various methods for defining very rich multi-axis maneuvers, for instance based on multisine/sum of sines signals, already exist. A new design method based on the wavelet transform allowing the definition of multi-axis inputs in the time-frequency domain has been developed. The compact representation chosen allows the user to define fairly complex maneuvers with very few parameters. This method is demonstrated using simulated flight test data from a high-quality Airbus A320 dynamic model. System identification is then performed with this data, and the results show that aerodynamic parameters can still be accurately estimated from these fairly simple multi-axis maneuvers.

On Time-Synchronized Stability and Control

2021 ◽  
pp. 1-14
Author(s):  
Dongyu Li ◽  
Haoyong Yu ◽  
Keng Peng Tee ◽  
Yan Wu ◽  
Shuzhi Sam Ge ◽  
...  
Keyword(s):  
Stability And Control ◽  
And Control
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