SpaceAMPL

This open source projects contains the AMPL models for a number of optimal control problems (OCP) of relevance to space engineering. All models are converging using the default parameters provided and using the default solver provided.

To run the models the following external (commercial) dependencies are needed:

1 - AMPL (also the edition limited to 100 variables is enough) 2 - SNOPT (in its AMPL version). Alternatively one could try other solvers (open source) by changing the relative line in the model file.

Most models output the result in a text file whose format is controlled by printf statments.

As an alternative, on-line free services such as the NEOS server can be used (in which case the .mod files could need some small modification to be adapted to the web interface)

The following folder/files are included in this distribution:

lander/: Folder containing OCP transcription for a planetary lander dynamics lander/impulsive/: Folder containing OCP impulsive transcription for a planetary lander dynamics lander/impulsive/main_thrusters.mod: Model for the OCP of a planetary descent (attitude dynamics actuated by thrusters) lander/impulsive/main_reaction_wheel.mod: Model for the OCP of a planetary descent (attitude dynamics actuated by a reaction wheel) lander/impulsive/main_simple_model.mod: Model for the OCP of a planetary descent (attitude dynamics excluded) lander/hs/: Folder containing OCP Hermite-Simpson (HS) transcription for a planetary lander dynamics lander/hs/main_thrusters.mod: Model for the OCP of a planetary descent (attitude dynamics actuated by thrusters)

dock/: Folder containing OCP transcription for docking type of problems (essentially those based on Hill-Clohessey-Wiltshire equations) dock/main.mod Model for the OCP of a simple two dimensional docking problem with a basic attitude actuation.

misc/: Miscellanea problems that could be used as tutorials misc/lambert_problem/main.mod: Model transcribing a simple lambert problem (i.e. a two point boundary value problem) misc/dubins_car: Folder containing different transcriptions for the classical Dubins Car Optimal Control Problem misc/dubins_car/tr/main.mod: Model transribing the OCP for the Dubins Car using a Trapezoidal collocation method misc/dubins_car/hs/main.mod: Model transcribing the OCP for the Dubins Car using an Hermite-Simpson collocation method
misc/dubins_car/impulsive/main.mod: Model transcribing the OCP for the Dubins Car using an impulsive collocation method