Project Updated PEG algorithm

[kwan3217]

I have posted on OrbitHangar a Java program which performs the multi-stage PEG algorithm, and contains other improvements which should make it more accurate and efficient, even for a single stage. It is a more-complete, but still not complete, implementation of the original PEG document.

This one, if you tell it how long a lower stage will burn, and what the initial acceleration and Isp of the upper stage are, will use both stages in an optimum-ish manner to achieve the target.

It is also capable of targeting the moon, for Ranger or Surveyor direct ascent missions. It is capable of flying one or two stages.

The original document contains a program for yaw steering, and an extension to an unlimited number of stages. I have not implemented these, but they should be pretty easy.

I have been working on this now for four years and have become sick of it. I can't even bring myself to update PEGAutopilot to use it. So, I'm putting it out there in the hopes that the Launch MFD guys will run with it. Anyone else can too, subject to the Library GPL.

 

[tblaxland]

Hey, thanks for the hard work getting it this far

 

[Enjo]

Oh, thanks for that. PEG's been a crucial addition to Launch MFD.

I have been working on this now for four years and have become sick of it.

I understand you. I've become sick of Launch MFD's direct ascent programme myself, and I think I'll have to stick a failure flag on it.

To all:
Right now I'm working on some games which I'd like to finish first. Meanwhile I'll contact Agentgonzo, just to let him know.

 

[agentgonzo]

I'm relatively busy at the moment with work and private life commitments. There were various things that I have tried over the past few months with LaunchMFD (improvements to the LAN-correction algorithm) but all were fruitless and didn't yield an improvement. I haven't even had the time to make some minor fixes to TransX. I will have time to start coding for Orbiter again, but it won't be for a few months I'm afraid, so hold tight (or hopefully Enjo will be able to take the upgrade over)

 

[T.Neo]

Will the next Launch MFD work without setting the atmosphere to 10km?

 

[agentgonzo]

Will the next Launch MFD work without setting the atmosphere to 10km?

It depends what you are talking about. If it's the Direct Ascent, then I'm not sure, but I think that from what Enjo has said, the Direct AScent method will get canned anyway.

For the normal ascent, the current version works fine (though not optimally) without setting the atmosphere to 10km as it's closed-loop guidance and all errors generated by the atmosphere on the initial ascent are fed-back into the guidance algorithm and your target pitch/yaw is calculated from there.

 

[Zachstar]

.....

This one, if you tell it how long a lower stage will burn, and what the initial acceleration and Isp of the upper stage are, will use both stages in an optimum-ish manner to achieve the target.
....

This is BIG!

The weakness of any adaptive Orbiter autopilot over the years have been the inability to "feel" That the upper stage above you isn't the same as the first stage.

You've cracked this riddle! Bravo!