Xidong Tang's Page

Xidong Tang, Ph.D
Electrical & Controls Integration Lab
GM R&D and Planning
Mail Code 480-106-390
Warren MI 48090
Tel: 586-986-5016
Fax: 586-986-3003
Email: xidong.tang@gm.com

o        Publications

o        Ph.D. Dissertation Abstract and Outline     (Advisor: Dr. Gang Tao)

o        Honors/Affiliations

o        Links

o        Book

Adaptive Control of Systems with Actuator Failures

Gang Tao, Shuhao Chen, Xidong Tang, and Suresh M. Joshi

315 pages, hardcover, ISBN: 1-85233-788-5, March 2004
Publisher: Springer-Verlag

Available on Amazon - Click here

Book Description: When an actuator fails, chaos or calamity can often ensue. It is because the actuator is the final step in the control chain, when the control system’s instructions are made physically real that failure can be so important and hard to compensate for. When the nature or location of the failure is unknown, the offsetting of consequent system uncertainties becomes even more awkward. Adaptive Control of Systems with Actuator Failures centers on counteracting situations in which unknown control inputs become indeterminately unresponsive over an uncertain period of time by adapting the responses of remaining functional control systems. Both “lock-in-place” and varying-value failures are dealt with. The results presented demonstrate: the existence of nominal plant-model matching controller structures with associated matching conditions for all possible failure patterns; the choice of a desirable adaptive controller structure; derivation of novel error models in the presence of failures; the design of adaptive laws allowing controllers to respond to combinations of uncertainties stemming from activator failures and system parameters. Adaptive Control of Systems with Actuator Failures will be of significance to control engineers generally and especially to both academics and industrial practitioners working on safety-critical systems or those in which full-blown fault identification and diagnosis is either too time consuming or too expensive.

This book presents our recent research results in designing and analyzing adaptive control schemes for systems with unknown actuator failures and unknown parameters. The main feature of the adaptive actuator failure compensation approach developed in this book is that no explicit fault detection and diagnosis procedure is used for failure compensation. An adaptive law automatically adjusts the controller parameters based on system response errors, so that the remaining functional actuators can be used to accommodate the actuator failures and systems parameter uncertainties.

o        Journal Papers

1.      X. D. Tang and G. Tao, “An adaptive output feedback controller using dynamic bounding with an aircraft control application,” International Journal of Adaptive Control and Signal Processing, 2009.

2.      Y. Liu, X. D. Tang, G. Tao, and S. M. Joshi, “Adaptive compensation of aircraft actuation failures using an engine differential model,” IEEE Transactions on Control Systems Technology , 2008.

3.      X. D. Tang, G. Tao, and S. M. Joshi, “Adaptive multivariable control of nonlinear systems with actuator failures and an application to flight control,” Automatica , 2007.

4.      G. Tao, X. D. Tang, S. H. Chen, J. T. Fei, and S. M. Joshi, “Adaptive failure compensation of two-state actuators for a morphing aircraft lateral model,” IEEE Transactions on Control Systems Technology , 2006.

5.      X. D. Tang, G. Tao, and S. M. Joshi, “Virtual grouping based adaptive actuator failure compensation for MIMO nonlinear systems,” IEEE Transactions on Automatic Control, 2005.

6.      X. D. Tang, G. Tao, and S. M. Joshi, “Adaptive output feedback actuator failure compensation for a class of nonlinear systems,” International Journal of Adaptive Control and Signal Processing, vol. 19, pp. 419444, 2005.

7.      X. D. Tang, G. Tao, L. F. Wang, and J. A. Stankovic, “Robust and adaptive actuator failure compensation designs for a rocket fairing structural-acoustic model,” IEEE Transactions on Aerospace and Electronic Systems, vol. 40, no. 4, pp. 13591366, 2004.

8.      X. D. Tang, G. Tao, and S. M. Joshi, “Adaptive actuator failure compensation for parametric strict feedback systems and an aircraft application,” Automatica, vol. 39, no. 11, pp. 19751982, 2003.

9.      G. Tao, X. D. Tang, and S. M. Joshi, “Adaptive output rejection of unmatched input disturbances,” Systems and Control Letters, vol. 47, no. 1, pp. 2535, September 2002.

o        Conference Papers

1.      X. D. Tang, G. Tao, and S. M. Joshi, “Adaptive Output Feedback Design for Actuator Failure Compensation Using Dynamic Bounding: Output Tracking and An Application,” Proceedings of the 2005 American Control Conference, pp. 31863191, Portland, Oregon, 2005.

2.      X. D. Tang, G. Tao, and S. M. Joshi, “Adaptive Output Feedback Design for Actuator Failure Compensation Using Dynamic Bounding: Output Regulation,” Proceedings of the 2005 American Control Conference, pp. 33153320, Portland, Oregon, 2005.

3.      Y. Liu, X. D. Tang, G. Tao, and S. M. Joshi, “Adaptive failure compensation control of autonomous robotic systems: application to a precision pointing hexapod, Proceedings of the 2005 AIAA Infotech@Aerospace, Washington, DC, September 2005.

4.      Y. Liu, X. D. Tang, G. Tao, and S. M. Joshi, “Adaptive failure compensation for aircraft flight control using engine differentials: regulation, Proceedings of the 2005 AIAA Infotech@Aerospace, Washington, DC, September 2005.

5.      X. D. Tang, G. Tao, and S. M. Joshi, “Adaptive output feedback actuator failure compensation for a class of state-dependent nonlinear systems,” Proceedings of the 42nd IEEE Conference on Decision and Control, pp. 16811686, Maui, Hawaii, USA, December 2003.

6.      X. D. Tang, G. Tao, and S. M. Joshi, “Adaptive compensation of actuator failures for nonlinear MIMO systems under relaxed design conditions,” Proceedings of the 2003 American Control Conference, pp. 51235128, Denver, CO, USA, June 2003.

7.      L. F. Wang, G. Tao, J. A. Stankovic, and X. D. Tang, “Real-time design and simulation of actuator failure compensation for rocket fairing vibration reduction,” Proceedings of the 2003 American Control Conference, pp. 515520, Denver, CO, USA, June 2003.

8.      E. F. Kececi, X. D. Tang, and G. Tao, “Adaptive actuator failure compensation for concurrently actuated manipulators,” Proceedings of the 5th IFAC Symposium on Fault Detection, Supervision and Safety of Technical Processes, pp. 411416, Washington, D.C., USA, June 2003.

9.      E. F. Kececi, X. D. Tang, and G. Tao, “Adaptive actuator failure compensation for cooperating multiple manipulator systems,” Proceedings of the 5th IFAC Symposium on Fault Detection, Supervision and Safety of Technical Processes, pp. 417422, Washington, D.C., USA, June 2003.

10. L. F. Wang, X. D. Tang, G. Tao, and J. A. Stankovic, “Actuator failure compensation schemes for vibration control of a rocket fairing model,” Proceedings of the 5th IFAC Symposium on Fault Detection, Supervision and Safety of Technical Processes, pp. 175180, Washington, D.C., USA, June, 2003.

11. X. D. Tang, G. Tao, and S. M. Joshi, “Compensation of nonlinear MIMO systems for uncertain actuator failures with an application to aircraft control,” Proceedings of the 41st IEEE Conference on Decision and Control, pp. 12451250, Las Vegas, NV, USA, December 2002.

12. X. D. Tang, G. Tao, and S. M. Joshi, “Adaptive actuator failure compensation for parametric-strict-feedback systems and an aircraft application,” Proceedings of the 2002 AIAA Guidance, Navigation, and Control Conference, Monterey, CA, USA, August 2002.

13. X. D. Tang, G. Tao, and S. M. Joshi, “An adaptive control scheme for output feedback nonlinear systems with actuator failures,” Proceedings of the 15th International Federation of Automatic Control World Congress, T-Tu-A03, Barcelona, Spain, July 2002.

14. X. D. Tang and G. Tao, “Adaptive actuator failure compensation for feedback linearizable systems,” Proceedings of the 4th World Congress on Intelligent Control and Automation (WCICA'02), Shanghai, China, June, 2002.

15. X. D. Tang, G. Tao, and S. M. Joshi, “Adaptive control of parametric-strict-feedback nonlinear systems with actuator failures,” Proceedings of the 40th IEEE Conference on Decision and Control, pp. 16131614, Orlando, FL, USA, December 2001.

16. X. D. Tang, G. Tao, and S. M. Joshi, “Adaptive actuator failure compensation control of parametric-strict-feedback systems with zero dynamics,” Proceedings of the 40th IEEE Conference on Decision and Control, pp. 20312036, Orlando, FL, USA, Dec. 2001.

17. X. D. Tang, G. Tao, and S. M. Joshi, “Adaptive actuator failure compensation for nonlinear systems,” Proceedings of the 2001 International Symposium on Adaptive and Intelligent Systems and Control, Charlottesville, VA, USA, June, 2001.

18. G. Tao, X. D. Tang, and S. M. Joshi, “Output tracking actuator failure compensation control,” Proceedings of the 2001 American Control Conference, pp. 18211826, Arlington, VA, USA, June 2001.

19. X. D. Tang, G. Tao, and S. M. Joshi, “Adaptive actuator failure compensation: nonlinear dynamics,” Proceedings of the 35th Annual Conference on Information Sciences and Systems, vol. II, pp. TP6: 685690, Baltimore, MD, USA, March 2001.

o        Reports

“Robust adaptive control in the presence of uncertainties and failures,” quarterly reports for the National Aeronautics and Space Administration, September 2000 August 2005.

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o        Ph.D. Dissertation

Abstract: Actuator failures have damaging effect on the performance of control systems, leading to undesired system behavior or even instability. Actuator failures are unknown in terms of failure time instants, failure patterns, and failure parameters. For system safety and reliability, the compensation of actuator failures is of both theoretical and practical significance. This dissertation is to further the study of adaptive designs for actuator failure compensation to nonlinear systems. In this dissertation a theoretical framework for adaptive control of nonlinear systems with actuator failures and system uncertainties is established. The contributions are the development of new adaptive nonlinear control schemes to handle unknown actuator failures for convergent tracking performance, the specification of conditions as a guideline for applications and system designs, and the extension of the adaptive nonlinear control theory. In the dissertation, adaptive actuator failure compensation is studied for several classes of nonlinear systems. In particular, adaptive state feedback schemes are developed for feedback linearizable systems and parametric strict-feedback systems. Adaptive output feedback schemes are deigned for output-feedback systems and a class of systems with unknown state-dependent nonlinearities. Furthermore, adaptive designs are addressed for MIMO systems with actuator failures, based on two grouping techniques: fixed grouping and virtual grouping. Theoretical issues such as controller structures, actuation schemes, zero dynamics, observation, grouping conditions, closed-loop stability, and tracking performance are extensively investigated. For each scheme, design conditions are clarified and detailed stability and performance analysis is presented. A variety of applications including a wing-rock model, twin otter aircraft, hypersonic aircraft, and cooperative multiple manipulators are addressed with simulation results showing the effectiveness of the proposed adaptive compensation schemes.

Outline:

Abstract

1.      Introduction

1.1.  Research Motivation

1.2.  Literature Overview

1.3.  Dissertation Outline

2.      Problem Formulation and Background

2.1.  Control Problem

2.2.  Background

2.2.1.     Adaptive Control

2.2.2.     Related Work in the Linear Case

2.2.3.     Nonlinear Control

2.2.4.     Feedback Linearizable Systems

2.2.5.     Parametric Strict-Feedback Systems

2.2.6.     Output-Feedback Systems

3.      Designs for Feedback Linearizable Systems

3.1.  Problem Statement

3.2.  An Adaptive Compensation Design

3.3.  A Design with Relaxed Conditions

4.      Designs for Parametric Strict-Feedback Systems without Zero Dynamics

4.1.  Problem Statement

4.1.1.     Actuation Model I

4.1.2.     Actuation Model II

4.2.  Design for Actuation Model I

4.2.1.     Output Matching Design

4.2.2.     Adaptive Design

4.3.  Design for Actuation Model II

4.3.1.     Output Matching Design

4.3.2.     Adaptive Design

4.4.  Simulation Study

5.      Designs for Parametric Strict-Feedback Systems with Zero Dynamics

5.1.  Problem Statement

5.2.  Adaptive Compensation Designs

5.2.1.     An Adaptive Compensation Design

5.2.2.     A Design with Relaxed Conditions

5.3.  An Application to A Twin Otter Aircraft

5.4.  Simulation Results

6.      Design for Output-Feedback Systems

6.1.  Problem Statement

6.2.  Adaptive Compensation Design

6.2.1.     Observer Design

6.2.2.     Backstepping Design

6.3.  Stability Analysis

7.      Design for Systems with State-Dependent Nonlinearities

7.1.  Problem Statement

7.2.  Adaptive Compensation Design

7.2.1.     State Observation Scheme

7.2.2.     Adaptive Backstepping Design

7.2.3.     Stability Analysis

7.3.  An Application to A Hypersonic Aircraft

7.3.1.     Aircraft Dynamic Model

7.3.2.     Adaptive Design

7.3.3.     Stability Analysis

7.3.4.     Simulation Results

8.      Designs for MIMO Systems

8.1.  Problem Statement

8.2.  Fixed-Grouping-Based Design

8.3.  An Application to A Nonlinear Aircraft Model

8.4.  Virtual-Grouping-Based Design

8.4.1.     Virtual Grouping

8.4.2.     Main Result

8.4.3.     Simulation Study

8.5.  An Application of Virtual Grouping to Cooperating Multiple Manipulators

9.      Conclusions

References


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o        Honors/Affiliations

o        Louis T. Rader Graduate Research Award, University of Virginia, 2005.

o        Full Member, Sigma Xi, The Scientific Research Society.

o        Student Member, IEEE.

o        Active Reviewer for IEEE and IFAC, Journals and conferences.

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o        Links

Electrical and Computer Engineering at UVA

General Motors R&D and Planning

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