SuccessiveConvexification

Implementation of Successive Convexification for 6-DoF Mars Rocket Powered Landing with Free-Final-Time

Reqires python3, matplotlib, numpy, scipy, sympy and cvxpy 1.0.0.

Since cvxpy 1.0.0 only supports Mac and Linux, Windows users are reccomended to use the Windows Subsystem for Linux (WSL) and Ubuntu. This is confirmed to work with reasonable speed (this is my development environment).

This branch:

• Erases MATLAB (.m) code for symbolic dynamics code generation

  • Replaced with sympy symbolic code generation

• Erases visualization code - for no reason other than I haven't yet used it really :)

  • Replaced with simple matplotlib plots

• Adds a tremendous amount of documentation and pythonic operations

• Mostly conforms to PEP8

• Due to intense hatred of variables ending with _, replaced all cvx variables ending with _ with proper names

  • v instead of _ denotes a cvx Variable
  • parm instead of _ denotes a cvx Parameter

• Replaced a great number of () with [] to clarify definitions of arrays versus function calls

• Replaced all dynamics functions in parameters with the sympy generated ones in dynamics_functions.py

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How to Run

Solve dynamics matrices and generate all functions : python dynamics_generation.py

Solve successive convex optimization problems : python main.py

Plot solution variables : python ./trajectory/plot.py

Short Video Visualization by Sven Niederberger - from the master branch

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Roadmap:

• Lift and Drag Dynamics With Aerodynamic Controls, in the spirit of this paper by Liu

• Automatic scaling of inputs from real-world dimensional scenarios to dimensionless solution inputs, and the reverse for the output

• C++ implementation likely to be forked from EmbersArc / Sven Niederberger's WIP C++ implementation

• Real-time performance evaluation in a realistic spaceflight simulation

History of this project:

• After the paper came out, I immediately started working on a python implementation. I worked for about 2 weeks until I came across Sven Niederberger's implementation on github! I ditched my implementation although it was nearly convergent.