TY  - JOUR
AU  - Assassa, Fady
AU  - Marquardt, Wolfgang
TI  - Dynamic optimization using adaptive direct multiple shooting
JO  - Computers & chemical engineering
VL  - 60
SN  - 0098-1354
CY  - Amsterdam [u.a.]
PB  - Elsevier Science
M1  - FZJ-2017-00546
SP  - 242 - 259
PY  - 2014
AB  - We present a wavelet-based grid refinement approach for direct multiple shooting applied to dynamic optimization problems. The algorithm, named adaptive multiple shooting, automatically generates a problem-dependent parameterization of the control profiles: Starting from an initially coarse parameterization, the control grid is refined iteratively using a wavelet analysis of the previously obtained optimal solution. Additional grid points are only inserted where required and redundant grid points are eliminated. Hence, the algorithm minimizes the number of grid points required to obtain accurate optimal control trajectories.First, we demonstrate the superiority of adaptive grid refinement over an equidistant discretization for the Williams–Otto semi-batch reactor employing multiple and single shooting. Here, the accuracy is checked using an optimal solution obtained by an indirect optimization approach. Second, we successfully demonstrate the efficiency of adaptive grid refinement compared to an equidistant discretization employing multiple shooting to a dynamically unstable HIPS (high impact polystyrene) polymerization reactor.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000327885100018
DO  - DOI:10.1016/j.compchemeng.2013.09.017
UR  - https://juser.fz-juelich.de/record/826313
ER  -