oyster_catcher

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About oyster_catcher

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  1. I'm please to announce the release of my first KSP mod HopperGuidance. I initially wrote this 2 years ago in Python using kRPC. I've now re-written it completely in C#, so its closely integrated with KSP and its 10x better because of it. Extract from README at https://github.com/oyster-catcher/HopperGuidance HopperGuidance ============== A KSP mod which enables the calculation of a fuel efficient trajectory in-flight to make a soft landing at a designated location respecting the capabilities of the craft. The craft will be steered automonously to follow this trajectory. You can choose many parameters of the trajectory to make it safe or more exciting. Features - Choose a landing latitude, longitude and altitude - Shows the trajectory to landing and require thrust vectors - Lets you tune the parameters to the craft You can choose a particular latitude and longitude and altitude to land at, although currently this works best close to the landing site such as within 10km. It must take less than 5 minutes to land. It certainly can't handle descent from orbit and it treats the planet surface as flat and doesn't take into account atmospheric drag, though can correct for it while flying. It may waste quite a bit of fuel trying to keep to the pre-calculated trajectory too. You can give it a try though, its all good fun. The algorithm used is aimed to be an implementation of the G-FOLD algorithm for fuel optimal diverts reputably used by Lars Blackmore for landing the SpaceX Falcon-9 rocket. However my algorithm is a simplified version of it and I've added some of my own constraints. See later. Please see the video https://www.youtube.com/watch?v=Ekywp-P6EBQ&t=301 References - "G-FOLD: A Real-Time Implementable Fuel Optimal Large Divert Guidance Algorithm for Planetary Pinpoint Landing" https://www.researchgate.net/publication/258676350_G-FOLD_A_Real-Time_Implementable_Fuel_Optimal_Large_Divert_Guidance_Algorithm_for_Planetary_Pinpoint_Landing. - "Convex Programming Approach to Powered Descent Guidance for Mars Landing" https://arc.aiaa.org/doi/abs/10.2514/1.27553 - "Minimum-Landing-Error Powered-Descent Guidance for Mars Landing Using Convex Optimization" http://www.larsblackmore.com/BlackmoreEtAlJGCD10.pdf Prerequistes ============ Works with KSP versions 1.8.1 to 1.10 and possibly beyond. If you want to run the solver outside of KSP you need python and matplotlib to show the trajectories. Installing ========== Copy GameData on top of the existing GameData folder in your KSP installation. Licensed under GPL v2. Includes ALGLIB (ALGLIB.net) also licensed under GPL v2. Much for info in the README included with the mod. Adrian Skilling adrian.skilling@gmail.com Please try it out from https://github.com/oyster-catcher/HopperGuidance. Please let me know if any problems. I'll be happy to try and fix them, Adrian. Fly safe!
  2. I'd like to announce a project I've been working on for some time to implement a simplified version of the G-FOLD automated soft-landing algorithm using the KRPC plugin, and the cvxopt convex optimisation library, all pretty dry sounding, OK, so what does it do? Well take a smallish fairly manoeuvrable craft, steer around a bit wildly (near the landing) spot, activate the soft-landing algorithm and it calculates a trajectory (shown visually) and thrust directions with minimum fuel use, and then auto-pilots the craft along the trajectory to land it craft anywhere you specify. Its been a lot of fun tweaking it to work reliably, it can now do some pretty dramatic recoveries. Heres a video that explains it better. Automated soft-landing montage video I've a much more detailed description here plus more videos including the crashes, and the python code is available here.