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"Exception" warning on Open Rocket Plots

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John Feller

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Hello all,

I was working on a 2 stage rocket on Open Rocket software. While the booster reaches its apogee, OR gives "Exception" warning as you can see from the attached image. What could be the reason of this warning? Normally, it should be plotted as the booster deployed the parachute and starts to descend.

Thanks in advance!

John
 

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MadRocketer

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I also get something like that. I have a five cluster sim that flies like a staged rocket. Sort of a work-around for side boosters. The four motors In the “first stage” have four different apogee, and one of them generally has the exception.
 

John Feller

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I also get something like that. I have a five cluster sim that flies like a staged rocket. Sort of a work-around for side boosters. The four motors In the “first stage” have four different apogee, and one of them generally has the exception.
I will inform you when I found something :)
 

H. Craig Miller

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I was working on a 2 stage rocket on Open Rocket software. While the booster reaches its apogee, ORK gives "Exception" warning as you can see from the attached image. What could be the reason of this warning? Normally, it should be plotted as the booster deployed the parachute and starts to descend.
Here are two adjusted files... including resizing the parachutes for more appropriate decent rates. The first is charge separation and the second is ignition separation.

Charge.png

Needless to say, there are significant difficulties with staging in OpenRocket 15.03, among other issues that will be corrected in the next release. As you manipulate these files, please keep in mind that anything that affects total flight time may cause the exception to reappear, including changing the size of the parachutes.

I hope this is helpful.
 

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neil_w

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Ah well, Craig beat me to it.

I tried the rocket in the new OR build and the motors were not found... I see that sometimes and I'm not sure the reason. The motors are there; the metadata must have changed or something. Once I added them back, the sim ran correctly with no exceptions.

To echo what Craig said, multi-stage simulation in 15.03 is weirdly touchy sometimes.
 

JoePfeiffer

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Craig and Neil have already said what's going on, but more specifically it literally had an arithmetic exception in the JVM. Several of the variables involved in calculating pitch and yaw went nuts, and the result was some sort of out of range value.

You can see this if you go to the plot/export dialog, export the data for your booster, and import it into a spreadsheet. We've got some code trying to dampen that sort of thing in the upcoming version.

As for missing motors, that's Issue https://github.com/openrocket/openrocket/issues/627
which someone with, umm, my initials is supposed to be working on...



 
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