Slewing problem with IRMV in Harrier

[Magnate]

I'm having a very specific problem with slewing the IRMV cursor.

 

A couple of  years ago I put the excellent DeltaSim ministick into my Thrustmaster Warthog throttle and it works very well. I'm currently flying Harrier, Apache and FA18 and the slew works fine in all modes.

However, I've recently had problems specific to slewing the IRMV seeker head on the right MFD in the Harrier. It slews perfectly up, left and right but doesn't want to move downwards. Or, it will stay stationary and then suddenly move down way past the desired point. There's no problem at all in the TPOD.

I'd read somewhere that unplugging the throttle might help, but that didn't work, and I've also changed to a different mission in case it was something specific to the mission I was flying.

Also, on a related note - the appearance of the Maverick seeker box on the HUD is a bit hit and miss. Sometimes it's there, and sometimes not.

Any ideas?

[Magnate]

Further to that post, here's a track file which demonstrates the unrestricted slewing in the TPOD and limited slew in IRMV mode. Some downwards movement is visible but there are repeated inputs which don't show any downwards response.

Mav seeker slew.trk

[scuba82]

Same Situation here, any news in this topic?

[scuba82]

I did some more investigations on this topic and I think, now I know what's happening and maybe have found a workaround...

First at all, it seems to be a general issue which not only effects the deltasim ministick but is more obviouse with it.

What I've found:

The IRMAV cursor slews perfectly in horizontal directions but wont move at all in vertical direction, if there is no input on the horizontal axis at the same time.

I've tested this with TDC horizontal/vertical inputs beeing bound to two sperate analog axis on potentiometers. While having the horizontal axis centered, the vertical doesn't move. (Maybe you could also reproduce it with the TDC horizontal input not bound to any physical device?). Giving just a slight input on the horizontal axis allows the vertical one to move freely.

That seems to be, why the issue is not that obviouse with the default TM throttle slew sensor, since it's really hard to move only one axis there, without interfering the other one. While  with the deltasim stick you can move one axis while the other one stayes still in center position. This may also explains the "jumping" of the cursor... If you try to move in vertical direction (nothing moves) and suddenly give a small pulses on the horizontal axis, the cursor seems to jump.

With this hypothesis, I tested again with the original TM slew sensor and yes, the vertical axis is also is behaving the same, but it's harder to reporduce because of the above mentioned reason.

 

My workaround(?):

I've slightly modified the TDC horizontal axis curve, to be much more aggressive in the center spot. (see screenshot) Now the slightest touch on the deltasim ministick results in a minimal  output on the horizontal axis. The output is not big enough to move the cursor (internal deadzone?) but allows the vertical axis to move.

 

 

I would highly appriciate if someone, effected by this issue, could test my workaround and give a short feedback, so we could push RAZBAM in the right direction on how to solve this.

 

[Ramsay]

2 hours ago, scuba82 said:

What I've found:

The IRMAV cursor slews perfectly in horizontal directions but wont move at all in vertical direction, if there is no input on the horizontal axis at the same time.

I've tested this with TDC horizontal/vertical inputs beeing bound to two sperate analog axis on potentiometers. While having the horizontal axis centered, the vertical doesn't move. (Maybe you could also reproduce it with the TDC horizontal input not bound to any physical device?). Giving just a slight input on the horizontal axis allows the vertical one to move freely.

Testing using a Xbox controller, I saw similar issues using TDC axis assignments, though the sticking axis was perhaps different to yours.

I had no issues with the axis when slewing over the sea.

Note that after using a TDC axis to slew the IRMAV, keyboard assignments for TDC slew (i.e. arrow keys Up, Down, Left and Right) didn't work until TDC Depress (action) was depressed and released.

 

Tested using DCS Open Beta 2.7.18.30765

Edited October 17, 2022 by Ramsay

[scuba82]

Thanks for testing and sharing the video ramsay. Gonna investigate further on this and maybe also try some other input sources.

 

[Ramsay]

21 hours ago, scuba82 said:

Gonna investigate further on this and maybe also try some other input sources.

A workaround is to have a bigger deadzone on the axis that doesn't "stick".

Detail

When there's a slew input on one of the axis (i.e. x-axis) the other axis won't slew (i.e. y-axis).

Increasing the deadzone on the TDC axis that never sticks fixes this, however the IRMav seems to "jump" a little bit more (as if the deadzone isn't taken into account when actioning the slew).

With the larger axis deadzone - switching to the keyboard, to slew the TDC, no longer requires TDC depress (action) before working after using analogue slews.

I'm not sure of the exact logic of this because clearly the IRMav will slew diagonally (i.e. inputs on both axis) but it looks likes there's a check/other logic going on when there are objects the IR sensor can lock onto.

 

Edited October 18, 2022 by Ramsay
Wording

[scuba82]

Funny...  you seem to have discovered the same thing but come up with an inverse solution to mine...   That seems to partially negate my hypothesis...

I have to test the bigger deadzone with my setup as well to see it also does the trick...

I've also noticed the "stickiness" of the cursor when it's locked to an IR source but guess that has nothing to do with initial issue of not beeing able to slew in one direction.

 

[Roastie]

Thanks Scuba82 for making me aware of this thread. I had a play around with both settings, And they both work for me. If I leave both horizontal and vertical standard with no deadzone or curve on the horizontal, the vertical will almost never move. With a deadzone or curve discribed by scuba82 the vertical does work.

I also expirience the stickiness scuba discribes, but I have no opinion on that yet.

I find it a super weird bug that slewing (tpod / tv) works except Mavs. I also fly a lot of F16, no problems there either.

I'm following this topic with interest

[shagrat]

Theory, here. Neither tested, nor sure it's the root cause, so you will need to check if it is valid: could the problem be the slew in relation to the distance?

Let me explain, what I mean. If the slew would move the seeker over the actual ground with a speed of say 0.5 - 2m per sec, instead of a certain degree change per sec, it would affect the perceived "speed". If the seeker looks at a far distant point, it would seem to not move "at all" while the closer to the aircraft (higher angle, off bore sight) the angle would change faster, with the same speed over ground. If the vertical movement happens to move over near hills/mountains and "jump" to the horizon or another mountain in the distance, it could make the seeker jerk between fast and slow change in angles, as it tries moving over the ground?

I think there was a similar issue with one of the Targeting Pod implementations in the past, where it did not use angles per second to move the seeker, but distance over ground at a speed defined by the axis.

I can't test myself at the moment.

[scuba82]

Yesterday evening a tested the deadzone on the "not sticking axis" and can confirm that even that solves the issue for me on the warthog throttle along with the deltasim slew stick upgrade.

So to summarize the issue, we have no clue why this is happening but have come up with two possible workarounds:

1) Set a small deadzone on the non sticking axis

2)Set a cure >=9 on the center position of the non sticking axis

@Roastie@Ramsay thank you for your tests

[Magnate]

Hi All,

I'm the original poster on this topic, but for some reason didn't get notifications about the replies.

So, let me start by saying thanks for engaging.

And thanks for resolving it - for me at least. Setting a small deadzone - value 2 - in the non-sticking axis seems to have done the trick.

I stumbled on this post while looking for a solution to another occasional Maverick problem. Sometimes I can't get a Laser Maverick to uncage. Earlier today, for instance, I attacked a group of four tanks with laser Mavericks and the first 3 all worked perfectly. When I came back for a fourth pass I couldn't get the Maverick to uncage. I tried deselecting and reselecting the Maverick, reset both the Master Arm and Master Modes but had no joy.

In the mission I just flew to test the IR Maverick slew workaround I also carried a pair of Laser Mavericks and had the same issue. First missile worked perfectly, but I couldn't get the second one to uncage.

I'm going to continue searching for a topic covering this, but if I can't find one I'll upload a trk file.