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A neuro-observer-based optimal control for nonaffine nonlinear systems with control input saturations

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Abstract

In this study, an adaptive neuro-observer-based optimal control (ANOPC) policy is introduced for unknown nonaffine nonlinear systems with control input constraints. Hamilton–Jacobi–Bellman (HJB) framework is employed to minimize a non-quadratic cost function corresponding to the constrained control input. ANOPC consists of both analytical and algebraic parts. In the analytical part, first, an observer-based neural network (NN) approximates uncertain system dynamics, and then another NN structure solves the HJB equation. In the algebraic part, the optimal control input that does not exceed the saturation bounds is generated. The weights of two NNs associated with observer and controller are simultaneously updated in an online manner. The ultimately uniformly boundedness (UUB) of all signals of the whole closed-loop system is ensured through Lyapunov’s direct method. Finally, two numerical examples are provided to confirm the effectiveness of the proposed control strategy.

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References

  1. Abu-Khalaf, M., & Lewis, F. L. (2005). Nearly optimal control laws for nonlinear systems with saturating actuators using a neural network HJB approach. Automatica, 41(5), 779–791.

    Article  MathSciNet  Google Scholar 

  2. Modares, H., Lewis, F. L., & Naghibi-Sistani, M.-B. (2013). Adaptive optimal control of unknown constrained-input systems using policy iteration and neural networks. IEEE Transactions on Neural Networks and Learning Systems, 24(10), 1513–1525.

    Article  Google Scholar 

  3. Huang, Y., & Jiang, H. (2015). Neural network observer-based optimal control for unknown nonlinear systems with control constraints. In International Joint Conference on Neural Networks (IJCNN). Killarney. https://doi.org/10.1109/IJCNN.2015.7280596.

  4. Esfandiari, K., Abdollahi, F., & Talebi, H. A. (2017). Adaptive near-optimal neuro controller for continuous-time nonaffine nonlinear systems with constrained input. Neural Networks, 93(195–204), 2017.

    MATH  Google Scholar 

  5. Esmailian, E., Farzanegan, B., Bagher Menhaj, M., & Ghassemi, H. (2018). A robust neuro-based adaptive control system design for a surface effect ship with uncertain dynamics and input saturation to cargo transfer at sea. Applied Ocean Research, 74, 59–68.

    Article  Google Scholar 

  6. Liu, D., Huang, Y., Wang, D., & Wei, Q. (2013). Neural-network-observer-based optimal control for unknown nonlinear systems using adaptive dynamic programming. International Journal of Control, 86(9), 1554–1566.

    Article  MathSciNet  Google Scholar 

  7. Bian, T., Jiang, Yu., & Jiang, Z.-P. (2014). Adaptive dynamic programming and optimal control of nonlinear nonaffine systems. Automatica, 50(10), 2624–2632.

    Article  MathSciNet  Google Scholar 

  8. Vrabie, D., & Lewis, F. L. (2009). Neural network approach to continuous-time direct adaptive optimal control for partially unknown nonlinear systems. Neural Networks, 22(3), 237–246.

    Article  Google Scholar 

  9. Werbos, P.J. (1992). Approximate dynamic programming for real-time control and neural modeling. In Handbook of Intelligent Control (pp. 493–526). New York: Van Nostrand Reinhold.

  10. Vamvoudakis, K. G., & Lewis, F. L. (2010). Online actor-critic algorithm to solve the continuous-time infinite horizon optimal control problem. Automatica, 46(5), 878–888.

    Article  MathSciNet  Google Scholar 

  11. Dierks, T., & Jagannathan, S. (2012). Online optimal control of affine nonlinear discrete-time systems with unknown internal dynamics by using time-based policy update. IEEE Transactions on Neural Networks and Learning Systems, 23(7), 1118–1129.

    Article  Google Scholar 

  12. Vrabie, D., Pastravanu, O., Abu-Khalaf, M., & Lewis, F. L. (2009). Adaptive optimal control for continuous-time linear systems based on policy iteration. Automatica, 45(2), 477–484.

    Article  MathSciNet  Google Scholar 

  13. Dierks, T., & Jagannathan, S. (2011). Online optimal control of nonlinear discrete-time systems using approximate dynamic programming. Journal of Control Theory and Applications, 9(3), 361–369.

    Article  MathSciNet  Google Scholar 

  14. Liu, D., Yang, X., & Li, H. (2013). Adaptive optimal control for a class of continuous-time affine nonlinear systems with unknown internal dynamics. Neural Computing and Applications, 23(7–8), 1843–1850.

    Article  Google Scholar 

  15. Yang, X., Liu, D., & Wei, Q. (2014). Online approximate optimal control for affine non-linear systems with unknown internal dynamics using adaptive dynamic programming. IET Control Theory & Applications, 8(16), 1676–1688.

    Article  MathSciNet  Google Scholar 

  16. Yang, X., & He, H. (2018). Self-learning robust optimal control for continuous-time nonlinear systems with mismatched disturbances. Neural Networks, 99, 19–30.

    Article  Google Scholar 

  17. Bhasin, S., Kamalapurkar, R., Johnson, M., Vamvoudakis, K. G., Lewis, F. L., & Dixon, W. E. (2013). A novel actor-critic-identifier architecture for approximate optimal control of uncertain nonlinear systems. Automatica, 49(1), 82–92.

    Article  MathSciNet  Google Scholar 

  18. Na, J., & Herrmann, G. (2014). Online adaptive approximate optimal tracking control with simplified dual approximation structure for continuous-time unknown nonlinear systems. IEEE/CAA Journal of Automatica Sinica, 1(4), 412–422.

    Article  Google Scholar 

  19. Liu, D., Wang, D., Wang, F.-Y., Li, H., & Yang, X. (2014). Neural-network-based online HJB solution for optimal robust guaranteed cost control of continuous-time uncertain nonlinear systems. IEEE Transactions on Cybernetics, 44(12), 2834–2847.

    Article  Google Scholar 

  20. Liu, D., Wei, Q., Wang, Di., Yang, X., & Li, H. (2017). Adaptive Dynamic Programming with Applications in Optimal Control. Springer.

  21. Modares, H., Lewis, F. L., & Sistani, M.-B. N. (2014). Online solution of nonquadratic two-player zero-sum games arising in the \({\rm H}_\infty\) control of constrained input systems. International Journal of Adaptive Control and Signal Processing, 28(3–5), 232–254.

    Article  MathSciNet  Google Scholar 

  22. Yang, X., Liu, D., & Huang, Y. (2013). Neural-network-based online optimal control for uncertain non-linear continuous-time systems with control constraints. IET Control Theory & Applications, 7(17), 2037–2047.

    Article  MathSciNet  Google Scholar 

  23. Yang, X., Liu, D., Wang, D., & Wei, Q. (2014). Discrete-time online learning control for a class of unknown nonaffine nonlinear systems using reinforcement learning. Neural Networks, 55, 30–41.

    Article  Google Scholar 

  24. Cybenko, G. (1989). Approximation by superpositions of a sigmoidal function. Mathematics of Control, Signals and Systems, 2(4), 303–314.

    Article  MathSciNet  Google Scholar 

  25. Hecht-Nielsen, R. (1992). Theory of the backpropagation neural network. In Neural Networks for Perception (pp. 65–93). Academic Press, Inc.

  26. Khalil, H.K. (2002). Nonlinear Systems (pp. 111–174). 3rd edn. Prentice Hall.

  27. Abdollahi, F., Talebi, H. A., & Patel, R. V. (2006). A stable neural network-based observer with application to flexible-joint manipulators. IEEE Transactions on Neural Networks, 17(1), 118–129.

    Article  Google Scholar 

  28. Tamura, S., & Tateishi, M. (1997). Capabilities of a four-layered feedforward neural network: four layers versus three. IEEE Transactions on Neural Networks, 8(2), 251–255.

    Article  Google Scholar 

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Correspondence to Amir Abolfazl Suratgar.

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Farzanegan, B., Zamani, M., Suratgar, A.A. et al. A neuro-observer-based optimal control for nonaffine nonlinear systems with control input saturations. Control Theory Technol. 19, 283–294 (2021). https://doi.org/10.1007/s11768-021-00045-z

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  • DOI: https://doi.org/10.1007/s11768-021-00045-z

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