一种圆形受限三体问题中小推力轨迹的直接转录求解器（可行估计器和优化器附matlab代码.zip

# CR3BP Low-Thrust Direct Transcription Solver A direct transcription solver (feasible estimator and optimizer) for low-thrust trajectories in circular restricted three-body problem. Optimized Trajectory | Mass and Thrust functions :-------------------------:|:-------------------------:  |  ## Features * Direct transcription solver for CR3BP+low-thrust trajectories * LGL node placement with user defined order * Two different solvers for different stages of trajectory design * Uses analytical jacobians for fast computation. * Uses sparse matrices to handle very large problems. * Feasible trajectory solver (**feasibleTranscription()**) * Estimate closest feasible trajectory from an initial guess * Levenberg-Marquardt with MATLAB fsolve solver * Optimizer (**optimalTranscription()**) * Optimize input trajectory with various objectives (thrust, propellant and time optimal) * Allows robust feasible trajectory estimation with dummy zero objective * Interior-Point with IPOPT optimizer ## Requirements * ## Installation * Download CR3BP Low-Thrust Direct Transcription Solver. * Download and install IPOPT optimizer. * Download LGL nodes-and-weights and copy to **external\\** folder. ## Usage / Manual * Use ```help feasibleTranscription``` for brief information on feasible solver. * Use ```help optimalTranscription``` for brief information on optimizer. * Examples of solver usage can be found in **examples\\** folder. ## Limitation / Issues * No automated mesh refinment strategy is implemented. * No direct access to LGL interpolation outside solver. * No easy way to add user-defined constraints (eg: periodicity). * Optimization issues with some sparse matrix operations. * Time fixed flag is buggy. * No inequality constraints for feasible transcription solver. * Small part of the code is built with modularity in mind, others are tailored for CR3BP+low-thrust. ## References - "Low-Thrust Trajectory Design for Tours of the Martian Moons", Beom Park - "A Collocation Approach for Computing Solar Sail Lunar Pole-Sitter Orbits", Martin T. Ozimek, Daniel J. Grebow, and Kathleen C. Howell - "MColl - Monte Collocation Trajectory Design Tool", Daniel J. Grebow and Thomas A. Pavlak - "Strategies for Low-Thrust Transfer Design Based on Direct Collocation Techniques", Robert E. Pritchett - "Survey of Direct Transcription for Low-Thrust Space Trajectory Optimization with Applications", Francesco Topputo and Chen Zhang - "Trajectory Design in the. Earth-Moon System and Lunar South Pole Coverage", Daniel J. Grebow - "Design of low-thrust transfers. from an NRHO to low lunar orbits-applications for small spacecraft", Beom Park, Kathleen C. Howell, and David C. Folta