A sufficient condition for robust internal stability of closed-loop systems with disturbance observer

For a class of uncertain generalized discrete linear system with norm-bounded parameter uncertainties, the state feedback robust control problem is studied. One sufficient condition for the solvability of the problem and the state feedback robust controller are obtained in terms of linear matrix inequalities. The designed controller guarantees that the closed-loop systems is regular, causal, stable and satisfies a prescribed norm bounded constraint for all admissible uncertain parameters under some conditions. The result of the normal discrete system can be regarded as a particular form of our conclusion. A simulation example is given to demonstrate the effectiveness of the proposed method.

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Optimal Disturbance Observer Design for High Tracking Performance in Motion Control Systems

Mathematics ◽

10.3390/math8091633 ◽

2020 ◽

Vol 8 (9) ◽

pp. 1633

Author(s):

Wonhee Kim ◽

Sangmin Suh

Keyword(s):

Disturbance Observer ◽

Closed Loop ◽

Inverse Dynamics ◽

Hard Disk Drives ◽

Observer Design ◽

Disk Drives ◽

Closed Loop Systems ◽

Baseline Weight ◽

The Stability ◽

Target Plant

In this paper, a stability-driven optimal disturbance observer (DO) is proposed. The proposed method does not require any plant inverse dynamics to detect introduced disturbances or a stabilizing Q filter. It does not require additional compensators to resolve causality problems, due to the relative degree, or filters to solve instability problems of non-minimum phase plants. Using this method enables wideband and narrowband disturbances to be attenuated by simply multiplying the corresponding peak filters by the baseline weight function. Furthermore, the proposed DO guarantees the stability of closed-loop systems because the already designed outer-loop systems are considered as a target plant to be stabilized and because of the Lyapunov stability-based H∞ control. In the application example, it was confirmed that the proposed method is effective, and the position error signals were improved by 20.9% in commercial hard disk drives and 36.6% in optical image stabilization systems.

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Estimation Error Based Disturbance Observer Design for Flexible Loop Shaping

Electronics ◽

10.3390/electronics7120358 ◽

2018 ◽

Vol 7 (12) ◽

pp. 358 ◽

Cited By ~ 2

Author(s):

Sangmin Suh

Keyword(s):

Disturbance Observer ◽

Closed Loop ◽

Control Structure ◽

Storage Systems ◽

Estimation Error ◽

Observer Design ◽

Experimental Results ◽

External Disturbances ◽

Flexible Loop ◽

Closed Loop Systems

This note presents an estimation error based disturbance observer (EEDOB) to reduce the effects of external disturbances. In the proposed control structure, a difference between an estimator output and a plant output is considered as an equivalent disturbance. Therefore, when a disturbance appears, the proposed disturbance observer (DOB) is activated. Unlike conventional DOB, this method does not require the plant inverse model or additional stabilizing filters. In addition, the proposed method always satisfies closed loop systems stability, which is definitely different from conventional DOB. To verify the effectiveness, this method was applied to commercial storage systems. From the experimental results, it is confirmed that tracking performance is improved by 23.5%.

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Resilient anti-disturbance H∞ control for turbofan systems

Transactions of the Institute of Measurement and Control ◽

10.1177/0142331220924145 ◽

2020 ◽

Vol 42 (14) ◽

pp. 2686-2697

Author(s):

Yankai Li ◽

Mou Chen ◽

Tao Li ◽

Huijiao Wang ◽

Yu Kang

Keyword(s):

Disturbance Observer ◽

Closed Loop ◽

Control Method ◽

Sufficient Conditions ◽

Lyapunov Stability Theory ◽

Control Technique ◽

Linear Matrix ◽

Asymptotically Stable ◽

Matrix Inequality ◽

Closed Loop Systems

The problem of [Formula: see text] control is investigated for turbofan systems with uncertain parameters and multiple disturbances in this paper. Some disturbances with partly known information are described via an external system, and other disturbances are assumed to be [Formula: see text] norm bounded. According to the disturbance-observer-based-control (DOBC) method and resilient [Formula: see text] control technique, a robust resilient controller is designed to reject and attenuate the influence of these disturbances, and guarantees that closed-loop systems are asymptotically stable with [Formula: see text] performance. Some solvable sufficient conditions are obtained based on the linear matrix inequality (LMI) technique and Lyapunov stability theory. Finally, a simulation is presented to show the robustness and effectiveness of the developed resilient anti-disturbance [Formula: see text] control method.

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On Stability in Nonsequential MIMO QFT Designs

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.1870043 ◽

2004 ◽

Vol 127 (1) ◽

pp. 98-104 ◽

Cited By ~ 7

Author(s):

Murray L. Kerr ◽

Suhada Jayasuriya ◽

Samuel F. Asokanthan

Keyword(s):

Design Methodology ◽

Closed Loop ◽

Stability Theorem ◽

Loop System ◽

Sufficient Condition ◽

Necessary And Sufficient Condition ◽

Closed Loop System ◽

Closed Loop Systems ◽

The Stability ◽

Necessary And Sufficient

This paper reexamines the stability of uncertain closed-loop systems resulting from the nonsequential (NS) MIMO QFT design methodology. By combining the effect of satisfying both the robust stability and robust performance specifications in a NS MIMO QFT design, a proof for the stability of the uncertain closed-loop system is derived. The stability theorem proves that, subject to the satisfaction of a critical necessary and sufficient condition, the original NS MIMO QFT design methodology will provide a robustly stable closed-loop system. This necessary and sufficient condition provides a useful existence test for a successful NS MIMO QFT design. The results expose the salient features of the NS MIMO QFT design methodology. Two 2×2 MIMO design examples are presented to illustrate the key features of the stability theorem.

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Neural Computation in Embodied Closed-Loop Systems for the Generation of Complex Behavior: From Biology to Technology

10.3389/978-2-88945-605-5 ◽

2018 ◽

Keyword(s):

Closed Loop ◽

Neural Computation ◽

Complex Behavior ◽

Closed Loop Systems

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METHOD OF SYNTHESIS OF CLOSED-LOOP SYSTEMS OF ACTIVE SHIELDING MAGNETIC FIELD OF POWER TRANSMISSION LINES

Tekhnichna Elektrodynamika ◽

10.15407/techned2016.04.008 ◽

2016 ◽

Vol 2016 (4) ◽

pp. 8-10 ◽

Cited By ~ 1

Author(s):

B.I. Kuznetsov ◽

◽

A.N. Turenko ◽

T.B. Nikitina ◽

A.V. Voloshko ◽

...

Keyword(s):

Magnetic Field ◽

Transmission Lines ◽

Closed Loop ◽

Power Transmission ◽

Power Transmission Lines ◽

Closed Loop Systems ◽

Active Shielding

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102-LB: Cross-Study Comparisons Done Right: An Illustration Using Two Pivotal Trials of Closed-Loop Systems

Diabetes ◽

10.2337/db20-102-lb ◽

2020 ◽

Vol 69 (Supplement 1) ◽

pp. 102-LB

Author(s):

MARC D. BRETON ◽

ROY BECK ◽

RICHARD M. BERGENSTAL ◽

BORIS KOVATCHEV

Keyword(s):

Closed Loop ◽

Closed Loop Systems

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Time in range for multiple technologies in type 1 diabetes: a systematic review and network meta-analysis

10.2337/figshare.12116691 ◽

2020 ◽

Author(s):

Anthony Pease ◽

Clement Lo ◽

Arul Earnest ◽

Velislava Kiriakova ◽

Danny Liew ◽

...

Keyword(s):

Systematic Review ◽

Type 1 Diabetes ◽

Closed Loop ◽

Meta Analysis ◽

Management Strategies ◽

Glucose Testing ◽

Closed Loop Systems ◽

Percent Time ◽

Time In Range

Background: Time-in-range is a key glycaemic metric, and comparisons of management technologies for this outcome are critical to guide device selection. Purpose: We conducted a systematic review and network meta-analysis to compare and rank technologies for time in glycaemic ranges. Data sources: We searched All Evidenced Based Medicine Reviews, CINAHL, EMBASE, MEDLINE, MEDLINE In-Process and other non-indexed citations, PROSPERO, PsycINFO, PubMed, and Web of Science until 24 April, 2019. Study selection: We included randomised controlled trials >2 weeks duration comparing technologies for management of type 1 diabetes in adults (>18 years of age), excluding pregnant women. Data extraction: Data were extracted using a predefined template. Outcomes were percent time with sensor glucose levels 3.9–10.0mmol/l (70–180mg/dL), >10.0mmol/L (180mg/dL), and <3.9mmol/L (70mg/dL). Data synthesis: We identified 16,772 publications, of which 14 eligible studies compared eight technologies comprising 1,043 participants. Closed loop systems lead to greater percent time-in-range than any other management strategy and was 17.85 (95% predictive interval [PrI] 7.56–28.14) higher than usual care of multiple daily injections with capillary glucose testing. Closed loop systems ranked best for percent time-in-range or above range utilising surface under the cumulative ranking curve (SUCRA–98.5 and 93.5 respectively). Closed loop systems also ranked highly for time below range (SUCRA–62.2). Limitations: Overall risk of bias ratings were moderate for all outcomes. Certainty of evidence was very low. Conclusions: In the first integrated comparison of multiple management strategies considering time-in-range, we found that the efficacy of closed loop systems appeared better than all other approaches.

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