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Title of Thesis

Sampled Data Regulation Based On Realizable Reconstruction Filter

Author(s)

Muwahida Liaquat

Institute/University/Department Details
College of Electrical And Mechanical Engineering / National University of Sciences and Technology, Islamabad
Session
2013
Subject
Electrical Engineering
Number of Pages
212
Keywords (Extracted from title, table of contents and abstract of thesis)
Realizable, Sampled, Reconstruction, Data, Filter, Based, Regulation

Abstract
This dissertation deals with the output feedback sampled-data regulation of a continuous system usually referred to as the plant.The output of the plant is required to asymptotically track a continuous reference signal, which in turn is assumed to be generated by an exogenous system. Only the samples of both the output of the plant as well as the reference signal are available for measurement.The problem is to design discrete observers for state estimation of both the plant and the exogenous system followed by a discrete controller.The discrete control signal generated by the controller is to be connected to the input of the plant by using some generalized hold device (GHD).The conventional zero order hold device is not a suitable candidate for tracking applications in general.A GHD incorporates required signal dynamics and hence captures the inter-sampling behavior through its impulsive nature.The result is an augmented system incorporating dynamics of the plant, exogenous system and GHD.The customary methods of designing a GHD may result in a higher order solution that could possibly compromise the stabilizability of the overall system. On the other hand, the classical reconstruction filter that recovers a continuous signal from its samples is not an option due to its non-causal nature.The commonly used approximations to the ideal reconstruction filter introduce a delay and hence are not suitable for closed-loop applications. A realizable reconstruction filter (RRF) is introduced in this dissertation that addresses the aforementioned limitations. RRF is essentially a specialized GHD that has its utility in both closed-loop and signal processing applications.The application of RRF for sampled-data regulation is explored for three important classes of systems.To begin with, a control scheme is developed for linear time invariant (LTI) systems.A couple of examples of its application on physical systems along with stability analysis demonstrate the effectiveness of the proposed scheme.Next, single input single output feedback linearizable systems are investigated in the framework of the suggested theory.An impulsive observer estimates the states and disturbances using samples of the plant output. Batch processed least square estimation for initialization results in improved transient behavior.Subsequently, a linearizing control enables to utilize the theory developed for LTI systems on this problem.The overall control scheme is demonstrated by examples.The proposed method is then extended to the sampled-data regulation of feedback linearizable MIMO systems with focus on n-link robotic manipulators.An example of PUMA 560 robotic manipulator is included in the discussion.A class of linear time varying systems can be transformed into LTI systems (usually though sinusoidal transformation).The consequence is that constant references get converted into sinusoidal signals.Active control of gyroscopic systems is one such example.This problem is also presented in the dissertation.Simulation of impulsive systems requires special considerations that are not handled by commonly available simulators.A simulation method is specifically developed for impulsive systems to facilitate closed-loop simulations.

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1,965 KB
S. No. ChapterTitle of the ChaptersPageSize (KB)
10CONTENTSvii
89 KB
21INTRODUCTION

1.1 Output Regulation
1.2 Output Regulation for Continuous Linear Systems
1.3 Output Regulation for Non-linear Systems
1.4 Sampled-data Control
1.5 Output Regulation for Sampled-data Systems
1.6 Impulsive Systems
1.7 Generalized Hold Devices (GHD)
1.8 Requirement of New Developments
1.9 Overview of the Thesis

1
269 KB
32DISCRETE TIME OUTPUT REGULATION ON SAMPLE-DATA SYSTEMS

2.1 Problem Formulation
2.2 Linear Exosystem
2.3 Discrete Controller / Observer
2.4 Example: Magnetic Levitation System

24
254 KB
43REALIZABLE RECONSTRUCTION FILTER

3.1 Ideal Reconstruction Filter
3.2 Zero-order Hold
3.3 First-order Hold
3.4 Realizable Reconstruction filter (RRF)
3.5 Reconstruction in the Presence of Noise
3.6 Reconstruction of Uncertain systems
3.7 Remarks

37
433 KB
54OUTPUT REGULATION FOR LINEAR SAMPLED-DATA SYSTEMS USING RRF

4.1 Sampled data Output Regulation with RRF
4.2 Stability Analysis
4.3 Examples
4.4 Remarks

70
440 KB
65SAMPLED DATA OUTPUT REGULATION OF FEEDBACK LINEARIZABLE SYSTEMS

5.1 Feedback Linearizable Systems
5.2 Impulsive Feedback Linearization
5.3 Stability Analysis
5.4 Initializing Non-linear Impulsive Observer
5.5 Example: Impulsive Linearization
5.6 Impulsive System Representation
5.7 Sampled-data Output Regulation via Discrete Observer
5.8 Sampled-data Output Regulation via Impulsive Observer
5.9 Remarks

97
429 KB
76SAMPLE DATA OUTPUT REGULATION OF N-LINK ROBOTIC MANIPULATOR

6.1 The Vector Normal Form
6.2 Problem Formulation
6.3 Linear Exosystem
6.4 Impulsive Feedback Linearization
6.5 Stability Analysis
6.6 Disturbance Estimation and Initialization of Impulsive Observer
6.7 Higher order RRF
6.8 Sampled-data Output Regulation Using RRF
6.9 Example
6.10 Remarks

130
308 KB
87SAMPLED DATA OUTPUT REGULATION OF TIME VARYING SYSTEMS

7.1 Problem Formulation
7.2 Sampled data Output Regulation with RRF
7.3 Example Tracking Control of Gyroscope
7.4 Remarks

149
269 KB
98CONCLUSIONS AND FUTURE SUGGESTIONS

8.1 Conclusions
8.2 Future Suggestions

164
115 KB
109REFERENCES AND APPENDIX168
469 KB