Abstract
This paper considers a class of delay fractional optimal control problems with free terminal time. The fractional derivatives in this class of problems are described in the Caputo sense and they can be of different orders. We first show that for this class of problems, the well-known time-scaling transformation for mapping the free time horizon into a fixed time interval yields a new fractional-order system with variable time-delay. Then, we propose an explicit numerical scheme for solving the resulting fractional time-delay system, which gives rise to a discrete-time optimal control problem. Furthermore, we derive gradient formulas of the cost and constraint functions with respect to decision variables. On this basis, a gradient-based optimization approach is developed to solve the resulting discrete-time optimal control problem. Finally, an example problems is solved to demonstrate the effectiveness of our proposed solution approach.


Similar content being viewed by others
References
Agrawal, O.: A general formulation and solution scheme for fractional optimal control problems. Nonlinear Dyn. 38, 323–337 (2004)
Boccia, A., Falugi, P., Maurer, H., Vinter, R.B.: Free time optimal control problems with time delays. In: Proceedings of the 52nd IEEE CDC. pp. 520–525, Florence, Italy (2013)
Caponetto, R., Dongola, G., Fortuna, L.: Fractional Order Systems: Modeling and Control Applications. World Scientific, London (2010)
Chai, Q., Wang, W.: A computational method for free terminal time optimal control problem governed by nonlinear time delayed systems. Appl. Math. Model. 53, 242–250 (2018)
Cong, N., Tuan, H.: Existence, uniqueness, and exponential boundedness of global solution to delay fractional differential equations. Mediter. J. Math. 14, 193 (2017)
Debeljković, D.: Time-Delay Systems. InTech, Rijeka (2011)
Gong, Z., Liu, C., Teo, K., Wang, S., Wu, Y.: Numerical solution of free final time fractional optimal control problems. Appl. Math. Comput. 405, 126270 (2021)
Hosseinpour, S., Nazemi, A., Tohidi, E.: Müntz-Legendre spectral collocation method for solving delay fractional optimal control problems. J. Comput. Appl. Math. 351, 344–363 (2019)
Hull, D.: Sufficient conditions for a minimum of the free-final-time optimal control problem. J. Optim. Theory Appl. 68, 275–286 (1991)
Kibass, A., Srivastava, A., Trujillo, I.: Theory and Application of Fractional Differential Equations. Elseveier, New York (2006)
Kumar, M.: Optimal design of fractional delay FIR filter using cuckoo search algorithm. Int. J. Circuit Theory Appl. 46, 2364–2379 (2018)
Liu, C., Gong, Z., Teo, K., Sun, J., Caccetta, L.: Robust multi-objective optimal switching control arising in 1,3-propanediol microbial fed-batch process. Nonlinear Anal. Hybrid Syst. 25, 1–20 (2017)
Liu, C., Gong, Z., Yu, C., Wang, S., Teo, K.: Optimal control computation for nonlinear fractional time-delay systems with state inequality constraints. J. Optim. Theory Appl. 191, 83–117 (2021)
Liu, C., Loxton, R., Teo, K.: A computational method for solving time-delay optimal control problems with free terminal time. Syst. Control Lett. 72, 53–60 (2014)
Marzban, H., Malakoutikhah, F.: Solution of delay fractional optimal control problems using a hybrid of block-pulse functions and orthonormal Taylor polynomials. J. Frankl. Inst. 356, 8182–8251 (2019)
Maurer, H.: Second order sufficient conditions for optimal control problems with free final time: the Ricati approach. SIAM J. Control Optim. 41, 380–403 (2002)
Maurer, H., Osmolovskii, N.: Second order sufficient conditions for time-optimal bang-bang control. SIAM J. Control Optim. 42, 2239–2263 (2004)
Monje, C., Chen, Y., Vinagre, B., Xue, D., Feliu, V.: Fractional-order Systems and Controls. Springer-Verlag, London (2010)
Nocedal, J., Wright, S.J.: Numerical Optimization. Springer-Verlag, New York (2006)
Pooseh, S., Almeida, R., Torres, D.: Fractional order optimal control problems with free terminal time. J. Ind. Manag. Optim. 10, 363–381 (2014)
Safaie, E., Farahi, M., Ardehaie, M.: An approximate method for numerically solving multi-dimensional delay fractional optimal control problems by Bernstein polynomials. Comput. Appl. Math. 34, 831–846 (2015)
Salati, A., Shamsi, M., Torres, D.: Direct transcription methods based on fractional integral approximation formulas for solving nonlinear fractional optimal control problems. Commun. Nonlinear Sci. Numer. Simul. 67, 334–350 (2019)
Sweilam, N., AL-Mekhlafi, S.: Optimal control for a time delay multi-strain tuberculosis fractional model: a numerical approach. IMA J. Math. Control Inform. 36, 317–340 (2019)
Teo, K., Goh, C., Lim, C.: A computational method for a class of dynamical optimization problems in which the terminal time is conditionally free. IMA J. Math. Control Inform. 6, 81–95 (1989)
Teo, K., Li, B., Yu, C., Rehbock, V.: Applied and Computational Optimal Control: A Control Parametrization Approach. Springer, Cham (2021)
Wang, Z., Hong, X., Shi, G.: Analysis of nonlinear dynamics and chaos in a fractional order financial system with time delay. Comput. Math. Appl. 62, 1531–1539 (2011)
Yu, Y.: Optimal control of a nonlinear time-Delay system in batch fermentation process. Math. Probl. Eng. (2014). https://doi.org/10.1155/2014/478081
Acknowledgements
This work was supported by the National Natural Science Foundation of China (Nos. 12271307 and 11771008), the Australian Research Council (No. DP190103361), the China Scholarship Council (No. 201902575002), and the Natural Science Foundation of Shandong Province, China (Nos. ZR2017MA005 and ZR2019MA031).
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
Springer Nature or its licensor holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Liu, C., Gong, Z., Wang, S. et al. Numerical solution of delay fractional optimal control problems with free terminal time. Optim Lett 17, 1359–1378 (2023). https://doi.org/10.1007/s11590-022-01926-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11590-022-01926-1