/OCDES

OCDE Simulator

Primary LanguageMATLABGNU General Public License v3.0GPL-3.0

OCDES: OCDE Simulator

Xiao Zhao, Forschungszentrum Jülich, 07.2020

This code is an extension of my work at Forschungszentrum Jülich.

Overview

OCDES is a MATLAB-based tool that performs numerical integration to solve Optimization-Constrained Differential Equations (OCDE):
dx = f(x,v), x(0)=x_0, (1a)

v∈arg min_v ⁡g(x,v), (1b)

s.t.h_i(x,v)=0, i=1,…,M, (1c)

l_j(x,v)≥0, j=1,…,N. (1d)

x∈R^m and v∈R^n. f:R^m×R^n→R^m, g:R^m×R^n→R,h_i:R^m×R^n→R , l_j:R^m×R^n→R are at least second order continuously differentiable. OCDES provides efficient numerical solution of OCDE by using local optimality condition. A sequence of DAE systems are generated and classical index-1 DAE simulator is applied to solve the derived DAE systems.

Basic Requirements

Matlab, version 2014 or higher.

Matlab Symbolic Toolbox

Installation

The simulator needs Matlab environment.

How to use OCDES

Please refer to the example demo1.m. General steps of using OCDES are:

(1) Define state variables x and optimization variables v in symbolic format.

(2) Define functions f, g, h, l in symbolic format.

(3) Give initial condition x(0) and initial guess of v(0).

(4) Specify options for solving the inner NLP for initialization

opt_init.tol_act: tolerance to check active inequality constraints

opt_init.optimoptions: Optimization options, cf. MATLAB optimoptions

opt_sol.MaxNoUptActiveSet: maximum number of updating active set

opt_sol.tol_feasible: feasibility tolerance

(5) Specify options for integration

tstart: starting time of simulation

tfinal: ending time of simulation

opt_sol.integrator: Selected integration

opt_sol.opt_integrator: Integration options

(7) Call sOCDE_main.m to solve the OCDE.

Citation

Please cite [1], if you use the code.

License

Copyright (c) 2020: Forschungszentrum Jülich GmbH, Jülich, Germany.

Author: Xiao Zhao, Email: Xiao.Zhao@outlook.de

References

[1] Zhao, Ploch, Noack, Wiechert, Mitsos, von Lieres, Analysis of local well-posedness of optimization-constrained differential equations by local optimality conditions, AIChE J., DOI:10.1002/aic.16548.