reported Extreme oscillations in motion after shuttle hook-up

[BrassEm]

There is an intermittent problem with Super Carrier launch motion output. While the motion is now so superior to the old carrier, this problem does happen occassionally and is a real deal breaker, literally!!! I have only tested with the F-18C so cannot confirm other aircraft yet. See my website for my motion rig details. www.brass-em.com

 

When the launch bar is going over the catapult shuttle there is some large motion surges which I assume is normal. However once the bar has dropped over the shuttle and after brakes have been applied the motion is still there in a continous hunting oscillation which cannot be stopped. (Esc key and start the mission again!!!!)

 

The normal catapult surge is around 2.5

 

 

 

Starting on the catapult and launching, after several traps and launches the oscillation hit.

 

 

 

A close up of the oscillations when they start...

 

 

 

Hopefully we will see this addressed in a change log soon. No carrier ops for me until then.

(Track and Log files too large to upload even zipped.)

 

 

 

.

[BrassEm]

Motion on Super Carrier has been vastly improved to 2.5.6.55960. Unfortunately the bizarre runaway shudder is still there when the alignment algorithm goes into hunting lining up the launch bar/aircraft over the shuttle.

 

This time I have a .trk!!!!! Apologies for the shagging around in the track. (Was testing out my new wing folding key assignments and was NOT expecting the runaway.) Obviously the problem occurs right at the end of the track with the cat lineup.

 

Pitch (green) spikes when braking has been applied. (Good!)

The braking prior to moving into launch line up shows that surge has gone into oscillation but died off. (Wasnt noticed in seat.)

 

Sway (orange) looked as though it might also go into oscillation in the lead up to the shuttle coupling.

 

Surge (red) breaks into oscillation when the bar goes over the shuttle.

User3 (blue) is just an amplification of Surge

 

 

f18 Syria 20201025.trk

dcs Jumpy.log

[BrassEm]

NO FIX - RELEASE OPEN BETA: 2.5.6.57264

 

Expect your motion rig to shake violently on shuttle hook up. Timeline is in Seconds.

 

http://www.brass-em.com/portal/g-seat-ii

 

 

 

f18 Syria 20201109 Jumpy.trk

dcs Jumpy 20201109.log

[Roller25]

Any fix inbound for this issue? Also really bad in the F-14.

[BIGNEWY]

I have mentioned it to the team, I dont have a motion rig to test this myself. 

[Bojanglez]

Hey guys,

confirming the issue BRASS addressed.

 

I am sitting on Motion Systems PS-3TM-350. Stuck in that oscillation he describes on any super carrier hook up.

No way to proceed through it. That's where the simulation ends for me.

Confirmed for T-45 mod and A-4E mod. Literally makes spawning "parking hot" useless.

First I thought it was the carriers movement that would mess it up but no. Did some testing with different setups in mission editor and can say that I was not able to eliminate the issue.

 

Please fix!!! Interaction with deck staff is half the experience. Especially in VR!

 

On another note. Man are we spoiled. Thanks ED for what you have created here. DCS, VR, Motion Platform, some additional gear = dream come true!

[Bojanglez]

Am 18.3.2021 um 11:14 schrieb BIGNEWY:

I have mentioned it to the team, I dont have a motion rig to test this myself. 

Any news on this newy? Im sure you guys have a lot on your plate and thank you for everything... But... maybe this is a quick fix(?). Sure would have a huge impact for motion platform users. Could you follow up on this? Thank you in advance!!! 

[BIGNEWY]

Sorry I have no news, I have asked the team to take another look. 

 

thanks

[Bojanglez]

Am 7.8.2021 um 18:06 schrieb BIGNEWY:

Sorry I have no news, I have asked the team to take another look. 

 

thanks

I would love to push this up again.

With Yaw shipping more and more rigs out to VR aviators this will become increasingly important.

By now I can confirm this problem for Yaw2 Pro hooking the F-14 into any super carrier. I believe Brass has brought forward enough data to be able to find the root of the issue but I would now be able (and of course willing) to provide additional documentation. Like Video of the platform or the YAW Platform input/output data.

Maybe we can go step by step. Do you see any way to push this subject a step further @BIGNEWY?

 

Best. And thank all of you ED heroes so much!

[BIGNEWY]

I have asked the team on my report again, if I do get any news I will share it. thanks

[BrassEm]

Many thanks BIGNEWY. The problem still exists. @Bojanglez Thank you for the follow up too! - After 2 years!

New video of Shudder.

@ 1:37 The whole Aircraft is shuffled across to align up. There is some shudder then. Once the launch bar goes over the shuttle, that is when the major 7g shudder occurs. See the graphs. Surge being the offender shown in red. The ground motion is usually amplified to give it some better fidelity but with this intermittent high g shudder, that is not feasible.

 

dcs.log Export.log Export.lua

Edited October 21, 2023 by BrassEm

[BrassEm]

I got excited... Wrong shake.

Still there....

 

 

 

DCS f-18 Problem 20231119.zip

[Bojanglez]

Thanks @BrassEm for keeping this alive.

I ran a little test again, because I also got excited with the patch notes. Confirming no change. I watched your video of your motion platform (looks cool). To me that almost looks like you could sit through it. My Yaw2 is giving me soooo much more back and forth on pitch that you feel like its trying to throw you out of the seat. I will make a video asap. It sooo rough.

I would really love to see ED fix the surge issue. Anyone flying Naval Ops in VR on any kind of motion rig will be very much turned off by this issue. I wonder why it would even happen to me because I programmed pitch and acc only to translate to pitch on my yaw2. Where in there is surge? So weird.

And thanks @BIGNEWYfor being so available. I find you guys are doing an amazing job connecting with the community. If I can support in any way please let me know.
PS. My issue with the yaw not getting any data (reddit post) seems to have resolved itself. Have only gotten it once more since. I'll keep an eye on it and keep recording telemetry just in case.

Edited December 27, 2023 by Bojanglez

[Bojanglez]

@BrassEm
Maybe a noob question: The tool you are using to display the data "DCS Export Grapher Variable Header v0.4.1" (I guess). Can't find it. How can I get it to get comparable graphs to yours?

[Swson]

During the small phase duration between being hooked by the holdback, launch bar pushed up, engines at idle and before post combustion is applied when ordered on a CVN with supercarrier, I noticed disturbing oscillations of the exported telemetry longitudinal acceleration value. This was observed on the raw input signal of FlyPTmover software that drives my MotionXP 6DOF motion platform and leads to very disturbing motion sickness effects while in VR. This effect is not existing as soon as PC is applied nor before being hooked to holdback or even before starting the acceleration phase on a ground runway and can’t be filtered in FlyPT whatever being the applied process to the value. This effect is not present, in same CVN configuration, engines at idle, if the flight begins directly linked to the catapult with the holdback installed as it is possible to find in test missions but it appears as soon as you have passed over the catapult shuttle  if you make a mission where you roll then make all ordered phases of the launch procedure. Of course this problem is not perceived if you are not using a motion platform managing the surge DOF as surge acceleration in m/s2 and mixed surged in pitch DOF so I am conscient it is a problem for few peoples. Anyway, any idea to fix that? 

Edited December 28, 2023 by Swson

[BIGNEWY]

We have a report open internally, but I have no news to share. 

if you have any video of this happening and what it looks like on the platform please attach it 

thank you

[Bojanglez]

Am 28.12.2023 um 09:33 schrieb Swson:

During the small phase duration between being hooked by the holdback, launch bar pushed up, engines at idle and before post combustion is applied when ordered on a CVN with supercarrier, I noticed disturbing oscillations of the exported telemetry longitudinal acceleration value. This was observed on the raw input signal of FlyPTmover software that drives my MotionXP 6DOF motion platform and leads to very disturbing motion sickness effects while in VR. This effect is not existing as soon as PC is applied nor before being hooked to holdback or even before starting the acceleration phase on a ground runway and can’t be filtered in FlyPT whatever being the applied process to the value. This effect is not present, in same CVN configuration, engines at idle, if the flight begins directly linked to the catapult with the holdback installed as it is possible to find in test missions but it appears as soon as you have passed over the catapult shuttle  if you make a mission where you roll then make all ordered phases of the launch procedure. Of course this problem is not perceived if you are not using a motion platform managing the surge DOF as surge acceleration in m/s2 and mixed surged in pitch DOF so I am conscient it is a problem for few peoples. Anyway, any idea to fix that? 

 

Perfectly in line with the problem described by @BrassEmand myself above. 
 

will try and take a video tomorrow.
 

I am kind of hesitant tho because for me its so violent and uncontrolled that I am scared it might damage my yaw2‘s gears.

[BrassEm]

I am sure that if more motion users were to try this shuttle hookup setup, they would feel this intermittent abnormality and report it if they knew that it is not being introduced by a fault with their motion rig.

After trying to come to terms with this problem, I believe that there is certain out of field parameters, or a combination, that trigger this feedback problem. And I am sure there are many mass, velocity, inertia and position parameters being tested for. There is obviously a software routine that ensures that the aircraft is lined up to suitable parameters for a successful cat shot. This software routine will, and does move the aircraft to realign it for the cat shot if the aircraft is out of position. I have seen the aircraft slide into position. However the oscillations do not always occur, so the parameters tested for in this routine that are being corrected for, are met most of the time, and only a specific set of parameter conditions will induce the oscillations.

Just throwing this out there. If for example the stationary aircraft is a large distance away from the correct shuttle hookup position, it has gone forward and past the correct position. The shuttle hookup routine moves the aircraft backwards into position, but mass and inertia is being calculated in the shuttle hookup routine. The move is so great that the calculated inertia of the aircraft overshoots the position of the aircraft nosewheel away past the desired shuttle hookup position. The routine should test to see if its move is satisfactory, which it is not, it has overshot backwards. So it does another calculation to correct the overshoot and move it forward. Inertia calculations do their thing and the aircraft overshoots in the forward direction. So the routine hunts backwards and forwards to try and put the aircraft into the right position. Now imagine if the aircraft had some added inertia by moving forward into the shuttle position when the routine is started. If friction is being calculated then it eventually may dampen the overshooting. A fix may be not to calculate inertia to influence the aircraft positioning in the shuttle hookup routine.

 

@Bojanglez The "Export Grapher" is a program I am writing in Visual Studio C# to help with understanding the DCS export values, as using Excel spreadsheets was way too clunky. Unfortunately it is not ready for distribution just yet and has not been beta tested also. I can understand your reluctance to test this problem as some motion rigs may not be that robust. Does ED really want to visually see our motion rigs being damaged before they fix this problem? We are talking about a raw high frequency, full amplitude swing 7.5g motion. What would that do to a real plane? Anyways, just make sure your values are turned way down, (but then it wouldn't look as drastic as it is, would it?).

 

@Swson Thanks for helping by reporting your valuable observations!

Edited January 6 by BrassEm
grammar

[Bojanglez]

@BrassEm I feel like you might have nailed it with this analysis. I lay awake at night thinking what might cause this to be able to create a shortcut for ED to fix it but totally lack the understanding whats actually calculated there. What you proposed feels like it might be it and is in line perfectly with my observations. I will try to record a video today… will turn my power settings way down just to be safe. 

Edited January 6 by Bojanglez

[Bojanglez]

@BIGNEWY

In this video you can clearly see the problem!

You can see a brief twitch when the launchbar goes ->onto<- the shuttle. Then I throttle up again to get it over the shuttle for hook up.

once over the shuttle and hooked up the show begins. Terrible!

After about 2 sec I pull the emergency cut off of the platform because I don’t want to damage my rig. 

This violent oscillation wont stop!! It will keep going. You can see clearly how this doesnt belong here.

Please tell me if I can support fixing this in any way. 
 

thanks  

[BIGNEWY]

1 hour ago, Bojanglez said:

@BIGNEWY

In this video you can clearly see the problem!

You can see a brief twitch when the launchbar goes ->onto<- the shuttle. Then I throttle up again to get it over the shuttle for hook up.

once over the shuttle and hooked up the show begins. Terrible!

After about 2 sec I pull the emergency cut off of the platform because I don’t want to damage my rig. 

This violent oscillation wont stop!! It will keep going. You can see clearly how this doesnt belong here.

Please tell me if I can support fixing this in any way. 
 

thanks  

IMG_4495.mov

thank you sir, I will share with the team 

[Bojanglez]

@BIGNEWY

any word from the team?

maybe an idea if this could be a qiuck fix or rather complicated?

In multiplayer spawning “take off from runway” is not ideal!

I get that motion platform owners are only a fraction of your audience. But we are certainly dedicated !

Thanks for all you guys are pulling off!

Edited March 23 by Bojanglez

[Nealius]

This may have extended beyond just motion platform issues, as I see extreme visual oscillations in motion while under tension. Sometimes even when simply taxiing up to the shuttle.