GPOPS-II (pronounced "GPOPS 2") is a general-purpose MATLAB software for solving continuous optimal control problems using hp-adaptive Gaussian quadrature collocation and sparse nonlinear programming. The acronym GPOPS stands for "General Purpose OPtimal Control Software", and the Roman numeral "II" refers to the fact that GPOPS-II is the second software of its type (that employs Gaussian quadrature integration).

GPOPS-II
Developer(s)Michael Patterson[1] and Anil V. Rao[2]
Initial releaseJanuary 2013; 11 years ago (2013-01)
Stable release
2.0 / 1 September 2015; 8 years ago (2015-09-01)
Written inMATLAB
Operating systemMac OS X, Linux, Windows
Available inEnglish
TypeNumerical optimization software
LicenseProprietary, Free-of-charge for K - 12 or classroom use. Licensing fees apply for all academic, not-for profit, and commercial use (outside of classroom use)
Websitegpops2.com

Problem Formulation edit

GPOPS-II[3] is designed to solve multiple-phase optimal control problems of the following mathematical form (where   is the number of phases):

 
subject to the dynamic constraints
 
the event constraints
 
the inequality path constraints
 
the static parameter constraints
 
and the integral constraints
 
where
 
and the integrals in each phase are defined as
 

It is important to note that the event constraints can contain any functions that relate information at the start and/or terminus of any phase (including relationships that include both static parameters and integrals) and that the phases themselves need not be sequential. It is noted that the approach to linking phases is based on well-known formulations in the literature.[4]

Method Employed by GPOPS-II edit

GPOPS-II uses a class of methods referred to as  -adaptive Gaussian quadrature collocation where the collocation points are the nodes of a Gauss quadrature (in this case, the Legendre-Gauss-Radau [LGR] points). The mesh consists of intervals into which the total time interval   in each phase is divided, and LGR collocation is performed in each interval. Because the mesh can be adapted such that both the degree of the polynomial used to approximate the state   and the width of each mesh interval can be different from interval to interval, the method is referred to as an  -adaptive method (where " " refers to the width of each mesh interval, while " " refers to the polynomial degree in each mesh interval). The LGR collocation method has been developed rigorously in Refs.,[5][6][7] while  -adaptive mesh refinement methods based on the LGR collocation method can be found in Refs., .[8][9][10][11]

Development edit

The development of GPOPS-II began in 2007. The code development name for the software was OptimalPrime, but was changed to GPOPS-II in late 2012 in order to keep with the lineage of the original version of GPOPS [12] which implemented global collocation using the Gauss pseudospectral method. The development of GPOPS-II continues today, with improvements that include the open-source algorithmic differentiation package ADiGator [13] and continued development of  -adaptive mesh refinement methods for optimal control.

Applications of GPOPS-II edit

GPOPS-II has been used extensively throughout the world both in academia and industry. Published academic research where GPOPS-II has been used includes Refs.[14][15][16] where the software has been used in applications such as performance optimization of Formula One race cars, Ref.[17] where the software has been used for minimum-time optimization of low-thrust orbital transfers, Ref.[18] where the software has been used for human performance in cycling, Ref.[19] where the software has been used for soft lunar landing, and Ref.[20] where the software has been used to optimize the motion of a bipedal robot.

References edit

  1. ^ "People".
  2. ^ Website of Anil V. Rao
  3. ^ Patterson, M. A.; Rao, A. V. (2014). "GPOPS-II: A MATLAB Software for Solving Multiple-Phase Optimal Control Problems Using hp-Adaptive Gaussian Quadrature Collocation Methods and Sparse Nonlinear Programming". ACM Transactions on Mathematical Software. 41 (1): 1:1–1:37. doi:10.1145/2558904.
  4. ^ Betts, John T. (2010). Practical Methods for Optimal Control and Estimation Using Nonlinear Programming. Philadelphia: SIAM Press. doi:10.1137/1.9780898718577. ISBN 9780898718577.
  5. ^ Garg, D.; Patterson, M. A.; Hager, W. W.; Rao, A. V.; Benson, D. A.; Huntington, G. T. (2010). "A Unified Framework for the Numerical Solution of Optimal Control Problems Using Pseudospectral Methods". Automatica. 46 (11): 1843–1851. doi:10.1016/j.automatica.2010.06.048.
  6. ^ Garg, D.; Hager, W. W.; Rao, A. V.; et al. (2011). "Pseudospectral Methods for Solving Infinite-Horizon Optimal Control Problems". Automatica. 47 (4): 829–837. doi:10.1016/j.automatica.2011.01.085.
  7. ^ Garg, D.; Patterson, M. A.; Darby, C. L.; Francolin, C.; Huntington, G. T.; Hager, W. W.; Rao, A. V.; et al. (2011). "Direct Trajectory Optimization and Costate Estimation of Finite-Horizon and Infinite-Horizon Optimal Control Problems Using a Radau Pseudospectral Method". Computational Optimization and Applications. 49 (2): 335–358. CiteSeerX 10.1.1.663.4215. doi:10.1007/s10589-009-9291-0. S2CID 8817072.
  8. ^ Darby, C. L.; Hager, W. W.; Rao, A. V.; et al. (2011). "An hp-Adaptive Pseudospectral Method for Solving Optimal Control Problems". Optimal Control Applications and Methods. 32 (4): 476–502. doi:10.1002/oca.957. S2CID 16065706.
  9. ^ Darby, C. L.; Hager, W. W.; Rao, A. V.; et al. (2011). "Direct Trajectory Optimization Using a Variable Low-Order Adaptive Pseudospectral Method". Journal of Spacecraft and Rockets. 48 (3): 433–445. Bibcode:2011JSpRo..48..433D. CiteSeerX 10.1.1.367.7092. doi:10.2514/1.52136.
  10. ^ Patterson, M. A.; Hager, W. W.; Rao, A. V. (2011). "A ph Mesh Refinement Method for Optimal Control". Optimal Control Applications and Methods. 36 (4): 398–421. doi:10.1002/oca.2114. S2CID 6266472.
  11. ^ Liu, F.; Hager, W. W.; Rao, A. V. (2015). "Adaptive Mesh Refinement for Optimal Control Using Nonsmoothness Detection and Mesh Size Reduction". Journal of the Franklin Institute - Engineering and Applied Mathematics. 352 (10): 4081–4106. doi:10.1016/j.jfranklin.2015.05.028.
  12. ^ Rao, A. V.; Benson, D. A.; Darby, C. L.; Patterson, M. A.; Francolin, C.; Sanders, I.; Huntington, G. T. (2010). "GPOPS: A MATLAB Software for Solving Multiple-Phase Optimal Control Problems Using the Gauss Pseudospectral Method". ACM Transactions on Mathematical Software. 37 (2): 22:1–22:39. doi:10.1145/1731022.1731032. S2CID 15375549.
  13. ^ Weinstein, M. J.; Rao, A. V. "ADiGator: A MATLAB Toolbox for Algorithmic Differentiation Using Source Transformation via Operator Overloading". ADiGator.
  14. ^ Perantoni, G.; Limebeer, D. J. N. (2015). "Optimal Control of a Formula One Car on a Three-Dimensional Track—Part 1: Track Modeling and Identification". Journal of Dynamic Systems, Measurement, and Control. 137 (2): 021010. doi:10.1115/1.4028253. S2CID 121951098.
  15. ^ Limebeer, D. J. N.; Perantoni, G. (2015). "Optimal Control of a Formula One Car on a Three-Dimensional Track—Part 2: Optimal Control". Journal of Dynamic Systems, Measurement, and Control. 137 (5): 051019. doi:10.1115/1.4029466.
  16. ^ Limebeer, D. J. N.; Perantoni, G.; Rao, A. V. (2014). "Optimal Control of Formula One Car Energy Recovery Systems". International Journal of Control. 87 (10): 2065–2080. Bibcode:2014IJC....87.2065L. doi:10.1080/00207179.2014.900705. S2CID 41823239.
  17. ^ Graham, K. F.; Rao, A. V. (2015). "Minimum-Time Trajectory Optimization of Many Revolution Low-Thrust Earth-Orbit Transfers". Journal of Spacecraft and Rockets. 52 (3): 711–727. doi:10.2514/1.a33187. S2CID 43633680.
  18. ^ Dahmen, T.; Saupeand, D. (2014). "Optimal pacing strategy for a race of two competing cyclists". Journal of Science and Cycling. 3 (2).
  19. ^ Moon, Y; Kwon, S (2014). "Lunar Soft Landing with Minimum-Mass Propulsion System Using H2O2/Kerosene Bipropellant Rocket System". Acta Astronautica. 99 (May–June): 153–157. Bibcode:2014AcAau..99..153M. doi:10.1016/j.actaastro.2014.02.003.
  20. ^ Haberland, M.; McClelland, H.; Kim, S.; Hong, D. (2006). "The Effect of Mass Distribution on Bipedal Robot Efficiency". International Journal of Robotics Research. 25 (11): 1087–1098. doi:10.1177/0278364906072449. S2CID 18209459.

External links edit