TY  - JOUR
AU  - Assassa, Fady
AU  - Marquardt, Wolfgang
TI  - Optimality-based grid adaptation for input-affine optimal control problems
JO  - Computers & chemical engineering
VL  - 92
SN  - 0098-1354
CY  - Amsterdam [u.a.]
PB  - Elsevier Science
M1  - FZJ-2017-00535
SP  - 189 - 203
PY  - 2016
AB  - This paper studies the solution accuracy of direct single-shooting in comparision to the solution of the continuous optimal control problem (OCP). First, a convergence relation between the solution of the nonlinear program and that of continuous OCP is analyzed by means of an exemplary problem. This example reveals that Pontryagin's Minimum Principle cannot be used as a stopping criterion for optimality-based control grid adaptation. Consequently, a novel grid refinement strategy is introduced, which is rather based on the switching function and thus limited to the class of input-affine OCPs. Grid points are eliminated and inserted such that the approximation of the optimality condition of the OCP, elucidated by the switching function, is improved. The suggested methodology is illustrated and compared to a previously published wavelet-based adaptation approach by means of two reactor optimization problems with different solution characteristics.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000380513500015
DO  - DOI:10.1016/j.compchemeng.2016.04.041
UR  - https://juser.fz-juelich.de/record/826302
ER  -