Publications

Open-source, object-oriented, multi-phase pseudospectral optimization using pyomo

Schlossman, Rachel S.; Williams, Kyle R.; Kozlowski, David M.; Parish, Julie M.

Multi-phase, pseudospectral optimization is employed in a variety of applications, but many of the world-class optimization libraries are closed-source. In this paper we formulate an open-source, object-oriented framework for dynamic optimization using the Pyomo modeling language. This strategy supports the reuse of common code for rapid, error-free model development. Flexibility of our framework is demonstrated on a series of dynamic optimization problems, including multi-phase trajectory optimization using highly accurate pseudospectral methods and controller gain optimization in the presence of stability margin constraints. We employ numerical procedures to improve convergence rates and solution accuracy. We validate our framework using GPOPS-II, a commercial, MATLAB-based optimization program, for a vehicle ascent problem. The trajectory results show close alignment with this state-of-the-art optimization suite.