Bug #27028

Hellfire AGM-114K issues with moving vehicles

Added by admin about 3 years ago. Updated about 2 years ago.

Status:Closed Start date:12/13/2011
Priority:High Due date:01/07/2012
Assignee:Nou % Done:

100%

Category:-
Target version:1.13
Component:sys_missileguidance Affected Version:
Close Reason:

Description

 Updated by HyperU2 about 5 hours ago

The targeting and flight seems to be fixed but they are useless against moving targets, is that intended?

#87 Updated by Nou about 2 hours ago

HyperU2 wrote:

The targeting and flight seems to be fixed but they are useless against moving targets, is that intended?

Sadly this is an issue that is for the most part out of our hands (though probably there could be some improvements for LOBL modes... maybe) because of how laser targets are updated in ACE to overcome limitations of network issues in Arma2 itself.

The lasers do not track smoothly in ACE, their postions only update every quarter second or so.

In the old code there was compensation that caused the missile to lock on to the vehicle that it was seeing the designator on, but the network issues would partially remain and it would be less realistic.

#88 Updated by HyperU2 about 1 hour ago

Bummer. Yeah I know it used to work. I tried to take on a convoy today and went 0 for 6. Hopefully that's not realistic either. lol Thanks.

ace_sys_missileguidance.pbo (234.9 kB) Sickboy, 01/03/2012 12:33

ace_sys_missileguidance.pbo (235 kB) Sickboy, 01/03/2012 22:02

Associated revisions

Revision b7222f84
Added by Sickboy about 3 years ago

~ CHANGED: Improved Laser Tracking reliability for local LaserMarkers. refs #27028

Revision 990ddc3a
Added by Sickboy about 3 years ago

~ CHANGED: Improved Laser Tracking reliability for remote LaserMarkers. refs #27028

Revision 859ce638
Added by Sickboy about 3 years ago

CHANGED: Increased Laser marker update frequency 2 times or more (depending on distance). refs #27028

Revision 6814693e
Added by Sickboy about 3 years ago

CHANGED: Do not broadcast position if not changed. refs #27028

Revision 977be9a4
Added by Sickboy about 3 years ago

~ Improved: Laser accuracy. refs #27028

Revision 87df8c3f
Added by Sickboy about 3 years ago

Improved: Laser accuracy, frequency is now every 2 frames. refs #27028

History

Updated by Sickboy about 3 years ago

  • Description updated (diff)
  • Status changed from New to Assigned
  • Assignee set to Nou
  • Target version set to 1.14
  • % Done changed from 0 to 10

Make them reliable please, asap if possible - so it can be included in Stable.

E.g if it would help, you can change the getPos function to use getPos instead of broadcasted getPos when the laser is local (at least useful for LOBL, and for LOAL with laser on the same computer).
For LOAL far distance the broadcasted getPos should be much more reliable than getPos when laser and gunship are on different machines.
Although for v1.60, the improved network simulation might have improved it, while also far distance can be tweaked separately from close distance.

Updated by Sickboy about 3 years ago

  • Status changed from Assigned to In progress
  • % Done changed from 10 to 30

Applied the change to ACE_fnc_getPosASL.

Anything else possible Nou?

Updated by Sickboy about 3 years ago

  • % Done changed from 30 to 40

Slightly raised the frequency of remote laser marker position updates to 5x per second instead of 4x.

Updated by Sickboy about 3 years ago

  • File ace_sys_missileguidance.pbo added

Attached improved version, please give it a spin HyperU2.

Updated by cyrilator about 3 years ago

Tested with improved version :

When trying to aim at a mobile target passing at 1500m in front of me from left to right (Stryker running at 40km/h) the missile hit 20-30 meters too late behind the target.

Updated by Sickboy about 3 years ago

Are you sure the improved pbo is properly installed etc (not like last time?)

Updated by Sickboy about 3 years ago

  • File ace_main.pbo added

Actually this time it's probably my fault :-p
Should use this ace_main.pbo for the updated function.

Updated by Sickboy about 3 years ago

  • File deleted (ace_main.pbo)

Updated by Sickboy about 3 years ago

  • File deleted (ace_sys_missileguidance.pbo)

Updated by Sickboy about 3 years ago

  • File ace_sys_missileguidance+ace_main-#27028-improved.7z added

Updated by cyrilator about 3 years ago

retested. it's more accurate now. I would say the missile now have precision of impact of 3-4 meters compared to the same target i previously tested (Stryker running at 30-40 km/h).

Updated by Sickboy about 3 years ago

  • % Done changed from 40 to 60
  • Component set to sys_missileguidance

Much better then, glad to hear ;-)
The rest is up to Nou. As workaround I suppose you can somewhat take it into account already.

Updated by Nou about 3 years ago

Yes, using the local getPos would be good for LOBL or whenever its local, but I am afraid of network issue if using the setPos command for it because its broadcasting those setPos actions as well as the broadcasted setVar position.

I'd also like to investigate in the future handing off projectiles and their guidance to the local laser owner if they are further away.

Updated by zGuba about 3 years ago

What about 1.60 visiblePos?

Updated by Nou about 3 years ago

Does that work when the target isn't visible?

Updated by HyperU2 about 3 years ago

Thanks for the ticket, I was questioning the worthiness of creating one in the other topic. Went to bed though. I'll give this one a try.

Updated by Sickboy about 3 years ago

  • % Done changed from 60 to 70

The Improvements are available as hotfix on Six Updater. Please run Verify and Repair on the @ACE, @ACEX and @CBA modfolder (or simply on the ACE Preset).
Will also be included with 1.13 stable.

Hopefully Nou can further improve reliability.

Updated by HyperU2 about 3 years ago

They do hit closer now, it's not perfect but it's easier to get a hit by leading the vehicle with the designator.

Updated by maturin about 3 years ago

I can observe laser designator lag with the TOW AH-1z, but the TOW is quite effective regardless. Is this just down to the direct trajectory of the missile or could there be some other reason.

Not using any updated .pbos.

Updated by maturin about 3 years ago

It appears that there are two issues.

1) Laser designator lagging a meter or two behind the aiming reticule. You can see this in FLIR. This happens with the TOW and Hellfire.
2) Missile lagging behind the laser designator and hitting where it was a few seconds ago. This only happens to the Hellfire. The TOW updates its trajectory more often or something.

Remember that SACLOS missiles got a different kind of scheduling (or whatever you call it) because of low-FPS problems.

Updated by Nou about 3 years ago

TOW is not laser guided, so the TOW has nothing to do with the updating of the laser.

Updated by cyrilator about 3 years ago

Sickboy wrote:

Slightly raised the frequency of remote laser marker position updates to 5x per second instead of 4x.

with 5x per second laser refreshing rate, the missile have a 2-3 meters radius precision of impact on a moving target (30km/h)

is it enough to have a realistic precision of impact ?
What would be the results with 6x per second laser refreshing rate ? (just to compare results)

would it be too accurate or still realistic enough ?

I just watched some videos showing Apache Hellfire missiles fired on moving targets and the missile seems to have a very high rate of impact.

Updated by Sickboy about 3 years ago

The frequency is low for REMOTE (not 'local') laser objects ONLY. Not because of simulating the laser designation system, but to reduce network traffic.
Which is a workaround for: #14191

This is not relevant when you are playing Single Player or when you are the one who is both lasing and firing missiles.

So it's up to Nou to improve the actual laser designator / hellfire reliability.

Updated by cyrilator about 3 years ago

remote lasering only ? you mean it would just increase accuracy when another player is using hand-held laser designator like SOFLAM ?

strangely it also has a repercussion on local lasering precision (when player lasering and shot missile himself).

the missile accuracy increase was abvious when you released the misisleguidance.pbo compared to the previous results. (I made both tests from apache gunner seat on moving Stryker)

before the new pbo : 20m radius accuracy
after the new pbo : 3m radius accuracy.

Updated by Sickboy about 3 years ago

No there were 2 changes at once. Local lasers used the same frequency as remote. Since the change, local uses full frequency instead of remote.
And Remote frequency was upped from 4 to 5x per second.

So as said; It's up to Nou to further improve precision of the actual hellfire/laser code.

Updated by Sickboy about 3 years ago

  • File ace_sys_missileguidance.pbo added
  • % Done changed from 70 to 90

Might've nipped it in the bud by improving LaserMarker update frequency, which was delayed as much as 10 frames due to the Pulse not dying / becoming objNull directly upon impact.

Please confirm :)

The workaround can (should!) be further improved, but only if confirmed to improve the behavior.

Updated by Sickboy about 3 years ago

  • File deleted (ace_sys_missileguidance+ace_main-#27028-improved.7z)

Updated by Sickboy about 3 years ago

  • File deleted (ace_sys_missileguidance.pbo)

Updated by Sickboy about 3 years ago

  • File ace_sys_missileguidance+ace_main-#27028-improved3.7z added

Improved the workaround further.

Also available on SU.

Updated by Sickboy about 3 years ago

Still seem to need some lead, wondering if something in the HF scripts (Final moment just before hit) can be improved, laser should be fine now :) Nou?

Updated by Nou about 3 years ago

I am not sure, maybe it can maneuver more quickly? There is no terminal leading code in the real Hellfire's autopilot.

Updated by cyrilator about 3 years ago

I tested again today, and when fired from Apache the missile can still have some trouble to hit targets who are moving at moderate speed (40km/h). Some hits had 15-20m gap.

I also tested with Cobra, and the missile was maneuvering very anarchically, hitting randomly on map even at a correct distance (1000m) and with a correct shooting angle (less than 20°).

Nou wrote:

I am not sure, maybe it can maneuver more quickly?

this could be helpful. Because during the last 100m of the flight, the missile need increased responsiveness, to match with the last laser dot position.

Updated by mr.g-c about 3 years ago

Someone did a research what RL behavior is? Is a Hellfire supposed to always hit moving vehicles? Any Numbers on Hit rates?
Personally i find 40km/h speed when the vehicle passes at longer ranges from left->right or vice versa pretty fast. I can imagine, tracking it with the little stick in the Helos Cockpit might be a PITA.

Updated by Sickboy about 3 years ago

  • Due date set to 01/07/2012
  • Priority changed from Normal to High

Nou - what is the status? Have you made any progress? When are you planning to?

Updated by rocko about 3 years ago

mr.g-c wrote:

Someone did a research what RL behavior is? Is a Hellfire supposed to always hit moving vehicles? Any Numbers on Hit rates?
Personally i find 40km/h speed when the vehicle passes at longer ranges from left->right or vice versa pretty fast. I can imagine, tracking it with the little stick in the Helos Cockpit might be a PITA.

Sounds reasonable to me.

Updated by UGLY58 about 3 years ago

Guys,

I am the source of RL data on this one, no more detail than that.

Take it from me that the emulation that Nou is building is as close to the real world performance that security and most importantly the game engine can manage.

The biggest factors that affect hiting the target with any guided weapon system are as follows.

1. Movement of Firing Platform
2. The ability of the sighting system on the platform to stabilize itself to over come point 1.
3. The skill of the operator combined with the use of the tracking systems build into the sight and its ability to maintain the cross hairs/laser on the target.
4. Movement of the target and the ability of the operator to maintain the right aim point. Leading target went out in the 80`s that is overcome by technology.
5. The accuracy of the missile itself - this has improved endlessly over the last 20 years. Swingfire was all luck, TOW was not bad, Hellfire is damn accurate. However points 1 -4 still apply to both and have equally improved.

So hovering Apache at 6 km on a static large target 100%

Maneuvering Apache firing at a motorcycle doing 70 - good luck.

In both cases the missile should hit where the laser is pointed - points 1-4 apply.

Game Engine - Lets not forget that your frame rate as a client and the servers frame rate are also a massive impact on the accuracy in game.

Updated by rocko about 3 years ago

Perhaps we should reduce the slew rate?

IMO gunning in a helicopter is like some kind of vehicle shooter, move crosshair around quick and wild.

Updated by cyrilator about 3 years ago

.

Updated by Nou about 3 years ago

The missiles are lagging behind the target, but thats not the missiles fault. Continued testing shows the laser target spot is NOT where your reticle is. Its lagging behind it. The missile is hitting where the laser target is, but the laser target isn't where your reticle is. :(

Updated by cyrilator about 3 years ago

Nou wrote:

The missiles are lagging behind the target, but thats not the missiles fault. Continued testing shows the laser target spot is NOT where your reticle is. Its lagging behind it. The missile is hitting where the laser target is, but the laser target isn't where your reticle is. :(

you right. laser dot is laggy.

Updated by Sickboy about 3 years ago

So what's the fix Nou? ;-)

Updated by Nou about 3 years ago

Not sure... :( I'm going to experiment with it more later.

Updated by Sickboy about 3 years ago

  • File ace_sys_missileguidance.pbo added

Hows this? LaserMarker update frequency is now 3 frames. Might be able to do 2 frames if the logic is adjusted - but 3 frames means 20 times updated per second at 60 FPS, and 10 times updated per second at 30 FPS.
If reduced to 2 frames, it's 30 times and 15 times respectively.

Any math boy around who can calculate needed update frequency if a target moves at 40 km/hr ?

I did notice btw that the Hellfires don't find the laser even at times it should, especially at distances like 4km.
Perhaps its just that I can't see the impact, but i've lost a lot of missiles.
Wondering if the hellfire laser seeker code isn't too strict.

Updated by Sickboy about 3 years ago

  • File deleted (ace_sys_missileguidance.pbo)

Updated by Sickboy about 3 years ago

  • File deleted (ace_sys_missileguidance+ace_main-#27028-improved3.7z)

Updated by Sickboy about 3 years ago

Okay, i've refactored the code and now the frequency is 2 frames. It uses 1 frame to fire the pulse, and generally speaking 1 frame to catch the range.

So 30 times a second on 60 fps, and 15 times a second on 30 fps.

More importantly, the lasermarker always lagged at least 1 frame behind the actual position, this is not the case anymore.

If there is now still trouble to hit the targets, then either:
  • Hellfire code is not accurate enough, needs more Nou love
  • Perhaps interpolation plays tricks on us here.
  • Needed frequency cannot be achieved in game (with custom implementation of laser pulse currently as is)

On a side note; TOF is missing on AH1 (intended?), and TOF acts wonky on AH64 when switching weapons, i've also seen a TOF of: scalar.scalar.

Updated by cyrilator about 3 years ago

Sickboy wrote:

On a side note; TOF is missing on AH1 (intended?), and TOF acts wonky on AH64 when switching weapons, i've also seen a TOF of: scalar.scalar.

yes, same issues observed.

Updated by Sickboy about 3 years ago

Ty cyril.

Looking forward to testing results for laser accuracy with attached pbo ;-)

Updated by Nou about 3 years ago

I just increased the guidance run rate by twice as much. This should help in some terminal maneuver situations. Remember moving too fast is still going to cause issues, even if the laser tracked perfectly there is no way for the missile to make huge corrections when its only a couple dozen meters off the ground. Remember, nice smooth tracks (I suggest using a joystick if you have one).

Updated by Sickboy about 3 years ago

Awesome, hopefully that settles it for the most part.
Will put signed on SU as hotfix once confirmed.

Updated by cyrilator about 3 years ago

Nou wrote:

...even if the laser tracked perfectly there is no way for the missile to make huge corrections when its only a couple dozen meters off the ground.

you right. the missile seems to have a good enough hit ratio now for targets moving at moderate speed. (-30kmh)

for fast moving targets, the missile guidance should remain difficult anyway. the gunner must anticipate the target movement by aiming a bit forward. the hit ratio logically decrease like IRL.

Updated by Sickboy about 3 years ago

  • Status changed from In progress to Closed
  • % Done changed from 90 to 100

Thanks for confirmation cyril. Will close the ticket as resolved for now.

Updated by Sickboy about 3 years ago

  • Target version changed from 1.14 to 1.13

Available in the latest ACE 1.13 Stable hotfix2 packages http://ace.dev-heaven.net/wagn/ACE_1_13.
(Besides already available on Six Updater hotfixes).

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