Abstract
Model Predictive Control (MPC) techniques often need to be deployed on a nonlinear dynamic model of the system to be controlled. This type of application of MPC is usually referred to as Nonlinear MPC (NMPC). Explicit approaches for NMPC are difficult to deploy, and one typically resorts to computing the solutions to the NMPC scheme on-line, i.e. implicitly. The difficulty then becomes one of performing the fairly heavy computations required to compute the NMPC solutions within the allotted time budget. In this chapter, we will present a summarized overview of the most commonly used techniques to approach this problem. We will focus on the main aspects of these approaches that are arguably keys to deploying real-time NMPC, namely: the problem discretization, path-following methods, and the structure of the underlying linear algebra. Our focus here will be on offering the reader an accessible overview of these crucial aspects.
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References
Albersmeyer, J., Diehl, M.: The lifted Newton method and its application in optimization. SIAM J. Optim. 20(3), 1655–1684 (2010)
Albersmeyer, J.: Adjoint-based algorithms and numerical methods for sensitivity generation and optimization of large scale dynamic systems. PhD thesis, Ruprecht-Karls-Universitität Heidelberg (2010)
Andersson, J., Åkesson, J., Diehl, M.: CasADi – a symbolic package for automatic differentiation and optimal control. In: Forth, S., Hovland, P., Phipps, E., Utke, J., Walther, A. (eds.) Recent Advances in Algorithmic Differentiation, Lecture Notes in Computational Science and Engineering, pp. 297–307. Springer, Berlin (2012)
Biegler, L.T.: An overview of simultaneous strategies for dynamic optimization. Chem. Eng. Process. 46, 1043–1053 (2007)
Biegler, L.T.: Nonlinear Programming. MOS-SIAM Series on Optimization. SIAM, Philadelphia (2010)
Bock, H.G., Plitt, K.J.: A multiple shooting algorithm for direct solution of optimal control problems. In: Proceedings of the IFAC World Congress, pp. 242–247. Pergamon Press, Oxford (1984)
Bock, H.G., Diehl, M., Leineweber, D.B., Schlöder, J.P.: Efficient direct multiple shooting in nonlinear model predictive control. In: Keil, F., Mackens, W., Voß, H., Werther, J. (eds.), Scientific Computing in Chemical Engineering II, vol. 2, pp. 218–227. Springer, Berlin (1999)
Bock, H.G., Diehl, M., Leineweber, D.B., Schlöder, J.P.: A direct multiple shooting method for real-time optimization of nonlinear DAE processes. In: Allgöwer, F., Zheng, A. (eds.) Nonlinear Predictive Control. Progress in Systems Theory, vol. 26, pp. 246–267. Birkhäuser, Basel (2000)
Bock, H.G., Diehl, M., Kostina, E.: SQP methods with inexact Jacobians for inequality constrained optimization. IWR-Preprint 04-XX, Universität Heidelberg, Heidelberg (2004)
Bücker, H.M., Petera, M., Vehreschild, A.: Chapter code optimization techniques in source transformations for interpreted languages. In: Advances in Automatic Differentiation, pp. 223–233. Springer, Berlin (2008)
Büskens, C., Maurer, H.: SQP-methods for solving optimal control problems with control and state constraints: adjoint variables, sensitivity analysis and real-time control. J. Comput. Appl. Math. 120, 85–108 (2000)
Diehl, M., Bock, H.G., Schlöder, J.P.: Newton-type methods for the approximate solution of nonlinear programming problems in real-time. In: Di Pillo, G., Murli, A. (eds.) High Performance Algorithms and Software for Nonlinear Optimization, pp. 177–200. Kluwer Academic Publishers, Norwell (2002)
Diehl, M., Findeisen, R., Allgöwer, F., Bock, H.G., Schlöder, J.P.: Nominal stability of the real-time iteration scheme for nonlinear model predictive control. Technical Report #1910, IMA, University of Minnesota (2003)
Diehl, M., Findeisen, R., Allgöwer, F., Schlöder, J.P., Bock, H.G.: Stability of nonlinear model predictive control in the presence of errors due to numerical online optimization. In: Proceedings of the IEEE Conference on Decision and Control (CDC), Maui, pp. 1419–1424 (2003)
Diehl, M., Findeisen, R., Allgöwer, F., Bock, H.G., Schlöder, J.P.: Nominal stability of the real-time iteration scheme for nonlinear model predictive control. IEE Proc. Control Theory Appl. 152(3), 296–308 (2005)
Diehl, M., Findeisen, R., Allgöwer, F.: A stabilizing real-time implementation of nonlinear model predictive control. In: Biegler, L., Ghattas, O., Heinkenschloss, M., Keyes, D., van Bloemen Waanders, B. (eds.) Real-Time and Online PDE-Constrained Optimization, pp. 23–52. SIAM, Philadelphia (2007)
Domahidi, A., Zgraggen, A., Zeilinger, M.N., Morari, M., Jones, C.N.: Efficient interior point methods for multistage problems arising in receding horizon control. In: Proceedings of the IEEE Conference on Decision and Control (CDC), Maui, December 2012, pp. 668–674
Ferreau, H.J., Bock, H.G., Diehl, M.: An online active set strategy for fast parametric quadratic programming in MPC applications. In: Proceedings of the IFAC Workshop on Nonlinear Model Predictive Control for Fast Systems, Grenoble, pp. 21–30 (2006). It is found on the official website of IFAC but without official version
Ferreau, H.J., Houska, B., Kraus, T., Diehl, M.: Numerical methods for embedded optimisation and their implementation within the ACADO toolkit. In: Mitkowski, W., Tadeusiewicz, R., Ligeza, A., Szymkat, M. (eds.) Proceedings of the 7th Conference Computer Methods and Systems, Krakow, November 2009, pp. 13–29. Oprogramowanie Naukowo-Techniczne
Ferreau, H.J., Kozma, A., Diehl, M.: A parallel active-set strategy to solve sparse parametric quadratic programs arising in MPC. In: Proceedings of the 4th IFAC Nonlinear Model Predictive Control Conference, Noordwijkerhout (2012)
Forsgren, A., Gill, P.E.: Primal-dual interior methods for nonconvex nonlinear programming. SIAM J. Optim. 8(4), 1132–1152 (1998)
Forsgren, A., Gill, P.E., Wright, M.H.: Interior point methods for nonlinear optimization. SIAM Rev. 44, 525–597 (2002)
Frasch, J.V., Wirsching, L., Sager, S., Bock, H.G.: Mixed-level iteration schemes for nonlinear model predictive control. In: Proceedings of the IFAC Conference on Nonlinear Model Predictive Control (2012)
Frasch, J.V., Vukov, M., Ferreau, H.J., Diehl, M.: A dual Newton strategy for the efficient solution of sparse quadratic programs arising in SQP-based nonlinear MPC (2013). Optimization Online 3972
Frison, G.: Algorithms and methods for fast model predictive control. PhD thesis, Technical University of Denmark (DTU) (2015)
Frison, G., Jørgensen, J.B.: A fast condensing method for solution of linear-quadratic control problems. In: Proceedings of the IEEE Conference on Decision and Control (CDC) (2013)
Frison, G., Sorensen, H.B., Dammann, B., Jørgensen, J.B.: High-performance small-scale solvers for linear model predictive control. In: Proceedings of the European Control Conference (ECC), June 2014, pp. 128–133
Garg, D., Patterson, M.A., Hager, W.W., Rao, A.V., Benson, D.A., Huntington, G.T.: A unified framework for the numerical solution of optimal control problems using pseudospectral methods. Automatica 46(11), 1843–1851 (2010)
Gay, D.M.: Automatic differentiation of nonlinear AMPL models. In: In Automatic Differentiation of Algorithms: Theory, Implementation and Application, pp. 61–73. SIAM, Philadelphia (1991)
Gill, P., Murray, W., Saunders, M.: SNOPT: an SQP algorithm for large-scale constrained optimization. SIAM Rev. 47(1), 99–131 (2005)
Gros, S., Quirynen, R., Diehl, M.: An improved real-time NMPC scheme for wind turbine control using spline-interpolated aerodynamic coefficients. In: Proceedings of the IEEE Conference on Decision and Control (CDC) (2014)
Gros, S., Quirynen, R., Schild, A., Diehl, M.: Implicit integrators for linear dynamics coupled to a nonlinear static feedback and application to wind turbine control. In: IFAC Conference (2017)
Hindmarsh, A.C., Brown, P.N., Grant, K.E., Lee, S.L., Serban, R., Shumaker, D.E., Woodward, C.S.: SUNDIALS: suite of nonlinear and differential/algebraic equation solvers. ACM Trans. Math. Softw. 31, 363–396 (2005)
Houska, B., Ferreau, H.J., Diehl, M.: An auto-generated real-time iteration algorithm for nonlinear MPC in the microsecondrange. Automatica 47(10), 2279–2285 (2011)
Jongen, H.Th., Weber, G.W.: On parametric nonlinear programming. Ann. Oper. Res. 27, 253–283 (1990)
Kirches, C., Wirsching, L., Sager, S., Bock, H.G.: Efficient numerics for nonlinear model predictive control. In: Recent Advances in Optimization and Its Applications in Engineering, pp. 339–357. Springer, Berlin (2010)
Kirches, C., Wirsching, L., Bock, H.G., Schlöder, J.P.: Efficient direct multiple shooting for nonlinear model predictive control on long horizons. J. Process Control 22(3), 540–550 (2012)
Kouzoupis, D., Ferreau, H.J., Peyrl, H., Diehl, M.: First-order methods in embedded nonlinear model predictive control. In: Proceedings of the European Control Conference (ECC) (2015)
Kouzoupis, D., Quirynen, R., Frasch, J.V., Diehl, M.: Block condensing for fast nonlinear MPC with the dual Newton strategy. In: Proceedings of the IFAC Conference on Nonlinear Model Predictive Control (NMPC) (2015)
Kvasnica, M., Rauova, I., Miroslav, F.: Automatic code generation for real-time implementation of model predictive control. In: Proceedings of the IEEE International Symposium on Computer-Aided Control System Design, Yokohama (2010)
Leibfritz, F., Sachs, E.W.: Inexact SQP interior point methods and large scale optimal control problems. SIAM J. Control Optim. 38(1), 272–293 (2006)
Liu, X., Sun, J.: A robust primal-dual interior-point algorithm for nonlinear programs. SIAM J. Optim. 14(4), 1163–1186 (2004)
Mehrotra, S.: On the implementation of a primal-dual interior point method. SIAM J. Optim. 2(4), 575–601 (1992)
Nocedal, J., Wright, S.J.: Numerical Optimization. Springer Series in Operations Research and Financial Engineering, 2nd edn. Springer, Berlin (2006)
Pantoja, J.F.A.D., Mayne, D.Q.: Sequential quadratic programming algorithm for discrete optimal control problems with control inequality constraints. Int. J. Control 53, 823–836 (1991)
Potra, F.A., Wright, S.J.: Interior-point methods. J. Comput. Appl. Math. 124, 281–302 (2000)
Potschka, A.: A direct method for the numerical solution of optimization problems with time-periodic PDE constraints. PhD thesis, University of Heidelberg (2011)
Quirynen, R.: Automatic code generation of Implicit Runge-Kutta integrators with continuous output for fast embedded optimization. Master’s thesis, KU Leuven, 2012
Quirynen, R., Vukov, M., Diehl, M.: Auto generation of implicit integrators for embedded NMPC with microsecond sampling times. In: Lazar, M., Allgöwer, F. (eds.) Proceedings of the 4th IFAC Nonlinear Model Predictive Control Conference, pp. 175–180 (2012)
Quirynen, R., Gros, S., Diehl, M.: Efficient NMPC for nonlinear models with linear subsystems. In: Proceedings of the IEEE Conference on Decision and Control (CDC), pp. 5101–5106 (2013)
Quirynen, R., Gros, S., Diehl, M.: Inexact Newton based lifted implicit integrators for fast nonlinear MPC. In: Proceedings of the IFAC Conference on Nonlinear Model Predictive Control (NMPC), pp. 32–38 (2015)
Quirynen, R., Gros, S., Diehl, M.: Lifted implicit integrators for direct optimal control. In: Proceedings of the IEEE Conference on Decision and Control (CDC) (2015)
Quirynen, R., Gros, S., Diehl, M.: Inexact newton-type optimization with iterated sensitivities. SIAM J. Optim. (2017)
Quirynen, R., Gros, S., Houska, B., Diehl, M.: Lifted collocation integrators for direct optimal control in ACADO toolkit. Mathematical Programming Computation (2017)
Quirynen, R., Houska, B., Diehl, M.: Efficient symmetric hessian propagation for direct optimal control. J. Process Control (2017)
Rao, C.V., Wright, S.J., Rawlings, J.B.: Application of interior-point methods to model predictive control. J. Optim. Theory Appl. 99, 723–757 (1998)
Schäfer, A.A.S., Bock, H.G., Schlöder, J.P., Leineweber, D.B.: An exact Hessian SQP method for ill-conditioned optimal control problems. IWR-Preprint 01-XX, Universität Heidelberg (2001)
Schmid, C., Biegler, L.T.: Quadratic programming methods for reduced Hessian SQP. Comput. Chem. Eng. 18(9), 817–832 (1994)
Shahzad, A., Goulart, P.J.: A new hot-start interior-point method for model predictive control. In: Proceedings of the IFAC World Congress (2011)
Steinbach, M.C.: A structured interior point SQP method for nonlinear optimal control problems. In: Bulirsch, R., Kraft, D. (eds.) Computation Optimal Control, pp. 213–222. Birkhäuser, Basel (1994)
Steinbach, M.C.: Structured interior point SQP methods in optimal control. Z. Angew. Math. Mech. 76(S3), 59–62 (1996)
von Stryk, O.: Numerical solution of optimal control problems by direct collocation. In: Optimal Control: Calculus of Variations, Optimal Control Theory and Numerical Methods, vol. 129. Bulirsch et al., 1993
Wächter, A.: An Interior Point Algorithm for Large-Scale Nonlinear Optimization with Applications in Process Engineering. PhD thesis, Carnegie Mellon University (2002)
Walther, A.: Automatic differentiation of explicit Runge-Kutta methods for optimal control. Comput. Optim. Appl. 36(1), 83–108 (2006)
Wirsching, L.: An SQP Algorithm with inexact derivatives for a direct multiple shooting method for optimal control problems. Master’s thesis, University of Heidelberg (2006)
Zanelli, A., Quirynen, R., Diehl, M.: An efficient inexact NMPC scheme with stability and feasibility guarantees. In: Proceedings of 10th IFAC Symposium on Nonlinear Control Systems, Monterey, August 2016
Zanelli, A., Quirynen, R., Jerez, J., Diehl, M.: A homotopy-based nonlinear interior-point method for NMPC. In: Proceedings of 20th IFAC World Congress, Toulouse, July 2017
Zavala, V.M., Biegler, L.T.: Nonlinear programming sensitivity for nonlinear state estimation and model predictive control. In: International Workshop on Assessment and Future Directions of Nonlinear Model Predictive Control (2008)
Zavala, V.M., Biegler, L.T.: The advanced step NMPC controller: optimality, stability and robustness. Automatica 45, 86–93 (2009)
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Gros, S. (2019). Implicit Non-convex Model Predictive Control. In: Raković, S., Levine, W. (eds) Handbook of Model Predictive Control. Control Engineering. Birkhäuser, Cham. https://doi.org/10.1007/978-3-319-77489-3_14
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