CV-9040 stabilisation is perfect on direct front and doesn't exist on 90 degree angle

[Lumituisku]

CV9040  has weird stabilisation that is nearly flawles to direct "Precice" front of vehicle... but doesn't seem to have no difference at all to unstabilized when 90 degree to side. 

 

 

[Ssnake]

At least as far as the weapon itself is concerned, that is correct (because, no cant correction).

[Lumituisku]

 

And I am sorry for poking busy bees nest with such "trivial" thing.  You guys have much more important things to do, I understand and agree with that. However this how CV9040 currently behaves is so mind boggling and makes little sense that id like to get to either understand why this is so.  Or in case that my hunch is correct to get it eventually fixed.

 

Currently hitting anything when moving is just as likely as it would be without stabilization unless firing direct front along where hull is pointing. 

 

On 2/7/2021 at 7:20 PM, Ssnake said:

At least as far as the weapon itself is concerned, that is correct (because, no cant correction).

 

I am sorry, but I do not fully understand what that means.

 

I understand "CANT" as Incline / Slant.   

 

I have been explained and illustrated in past how lacking "CANT" correction on FCS makes your shots fall off to one side when looking at target, because fire trajectory is usually mostly downwards due to gravity and vehicle FCS firing from side slope may expect shots to fall on similar angle, because it doesn't understand cant correction?   Or that is how I understood and remembered it.  

 

But this how CV9040 has stabilization so that gun is only stabilized to vehicle hull front doesn't make any sense at all.   Aren't gyros located to turret near gun?  Why would anyone locate those to hull?  What is point of having gun fully stabilized and only stabilized only when on fixed position aligned with HULL FRONT?  And any turning of turret to side makes ones aim even worse than on  much older tech such as T-55  or BMP-2?   Do old soviet tanks and AFVs have CANT correction? and much never.. 90s tech combat vehicle doesn't?   

 

More over..  I happened to look at the PDF manual of cv9040  that comes with steelbeast and saw this on page 4

 

Also.. I was wondering if something had changed since vehicle was introduced...  maybe new terrain or something made a past shortcoming more obvious? So I went to look at how video of cv9040 looked like and stumbled at this where in video is said  "Fully stabilized gun with first round hit cabability"   

 

 

 

 

 

Currently... this is not so CV9040 doesn't have first round hit capabily on the move.  Especially not so especially if trying to fire on the left or right side of AFV like what can be seen on the video.  I suppose, it could be that Esimgames has changed CV9040 later based on new information?  But I do hope that it isn't the case.

 

Also.. looking for more information of the matter..  I went to wikipedia and found this from - https://en.wikipedia.org/wiki/Combat_Vehicle_90  from list "Variants, 5.1 domestic"  

 

Especially interesting are 9040 A and B       On A  it mentiones that stabilization was added to "FRONT of the TURRET"     So stabilization point is in the turret not in the HULL as in currently on Steelbeast.

Atleast that is how I see it behaving when using CV9040.  Please try it and see what I mean and please explain if I am mistaken and what I have understood wrong.  

 

I understand that Wikipedia isn't most reliable source of information, even I gringe sometimes to some things I read from it. But these things seem that those would likely be correct and less likely exxaggerated bullshit. 

 

 

Thank you for reading this. You guys are awesome and do great work, your product, customer service and priorities of focus have won my heart even when I don't always fully agree with everything.  

 

 

 

Edited March 27, 2021 by Lumituisku

[Jartsev]

Certain properties of  CV9040's  FCS and stabilisation system were not obvious to the users  before introduction  of New Terrain and procedural bumps, because terrain was too smooth, and current rather surprising behavior is actually more-or-less correct(within software limitations).

[Lumituisku]

1 hour ago, Jartsev said:

Certain properties of  CV9040's  FCS and stabilisation system were not obvious to the users  before introduction  of New Terrain and procedural bumps, because terrain was too smooth, and current rather surprising behavior is actually more-or-less correct(within software limitations).

 

In matter of terrain, I suspected that to be the case.

 

But the way stabilization works still doesn't make sense to me. Especially when Esims own PDF, and Video reads and says cv9040 to have "fully stabilized gun with first round hit capability"

 

Ill try to explain myself that I will feel that I have been understood, for one last time.

 

Okay. So do I understand correctly that cv9040 has gyro or something similar located to hull and sensors on "gyro" detect movements on direction of hull front only?    That the "gyro" is not located to turret and sensors are not along axis of the gun to stabilize it?   

 

It just is so hard to understand this..  because  even if "gyro" was on the hull, there are many ways to make it so that it / sensors or "gyro" would be able to rotate as turret does.  

 

-

 

It sounds that CV9040-A model with external "gyro" on turret would have much better gun stabilization than Cv9040 B or C that we have in steelbeast.  because on those "gyro" would follow the gun and be on most responsive position where ever turret is turned.

 

Currently how it behaves on steelbeast is as if "gyro" would be located to hull  and sensors locked to hull front.   So that (without cant correction)  sensors do not not pick anything Aka do not stabilize gun when turret is on 90 degree angle to hull front  and on 45 angle would pick only 50%  of "gyro" feedback  etc. 

 

So if you kept up with what I'am saying... when turret is rotated on 90 degree to side of the HULL  there is no stabilization at all..   on  45 degree there is just 50% prosent stabilization..    that doesn't sound like "Fully stabilized"   more like.. 50% stabilized    and  to make it worse..  it is soo bad that even on front  if moving even a slowly, and turning turret even a degree from direct front...  it becomes nearly impossible to hit target unless point blank.   Surely real vehicle cannot be that bad?  

 

Especially when pretty much anythingt that has any kind of stabilization of any era  is far superior

 

 

it just...   if it is so on real B and C model...   Whyyyy they ever changed "gyro" from turret to hull 😵?   As that to me as I understand it, makes A-model to have superior potential stability to all directions  (though vulnerable)  over B- and C-models.  

 

-

 

Maybe and problaby I have missunderstood something and do not know something essential.

 

 

Thank you for patience and replies. 

Edited March 27, 2021 by Lumituisku

[Lumituisku]

Not sure if this is.. worth anything but this seems to be cv9040-B   And it seems that it is much better stabilized than in Steelbeast currendly.  Though still slightly fiddly.. but not as we have now where currendly there is little stabilization to speack of.  

 

 

Edited March 27, 2021 by Lumituisku

[Ssnake]

I can't rule out that the current model of the CV9040 fire control system has undiscovered issues. But as far as I remember the system does NOT correct for turret/weapon roll angle (=cant correction).

It's something that I remember well even if it's been 15+ years since we made it because I had a hard time believing it. So we checked multiple times, but it was confirmed by the customer. So, there it is.

 

Whether the total system behavior is 100% spot on I can't say. A lot changed ober the last 15 years which may have had an influence on global simulation fidelity for this specific system.

But I'm pretty confident that the lack of cant correction is not a mistake.

[Lumituisku]

1 hour ago, Ssnake said:

I can't rule out that the current model of the CV9040 fire control system has undiscovered issues. But as far as I remember the system does NOT correct for turret/weapon roll angle (=cant correction).

It's something that I remember well even if it's been 15+ years since we made it because I had a hard time believing it. So we checked multiple times, but it was confirmed by the customer. So, there it is.

 

Whether the total system behavior is 100% spot on I can't say. A lot changed ober the last 15 years which may have had an influence on global simulation fidelity for this specific system.

But I'm pretty confident that the lack of cant correction is not a mistake.

 

 😲

 

Wait..  are we talking of same thing here?     

 

This sounds like you would be talking of Roll angle when I am concerned of Pitch angle

you talking of FCS (where shots fall)  when I am concerned of gun staying on target  recardles own vehicle movements 

 

 

Gun only needs to be stabilized on Pitch angle to gun to have good stabilization if the stabilization gyro is on turret?   Weapon roll would be like like  what is said in aviation to be aileron roll?   Or on picture below  ROLL axis.  While I am concerned of Weapons  Pitch axis  stabilization.

 

 

So yeah if there is no cant correction that would affect FCS system when firing on unlevel surfaces, but not affect on stabilization of gun staying on target right?   Because from this picture above.. 

 

So If we assume turret / weapon as centerpoint..   

- Yaw axis is basically one that keeps turret stabilized as happens already.   what clearly works.  

- Roll axis, as I understand is what you mean with =  CANT control?  "turret/weapon roll angle (=cant correction)."   would be like this in picture - relation to weapon right?    So missing that wouldn't really affect weapon stabilization? It would affect where your shots land, if you fire enemies when you have some roll angle, because your system wouldn't know direction of gravity.

- Pitch axis is what I am concerned about..     because currently pitch axis...   well if you imagine this plane (hull) having a turret..   pitch axis on cv9040 is on  that plane (hull)  not on it's turret.. so when you turn that imaginary turret of plane (hull) to side... you have rabitly dimishing if any weapon / or turret pitch axis stabilization anymore because location of pitch axis detector is not in turret but in plane (hull).     

 

 

 

[Ssnake]

If the turret is off 90°, hull pitch == turret roll.

If the gun is not stabilized against roll, driving on a bumpy road or on a strong incline will make for very difficult gunnry, just what you observe.

 

Now, it's perfectly possible that our simulated hull is too sensitive to pitch because of the simplified hull suspension simulation combined with high-res terrain and the procedural bumps, and that the Swedish Army mostly utilizes service roads - especially in live gunnery training on firing ranges - so that the problem doesn't manifest so dramatically in observable live conditions.

[Assassin 7]

2 hours ago, Lumituisku said:

 

 😲

 

Wait..  are we talking of same thing here?     

 

This sounds like you would be talking of Roll angle when I am concerned of Pitch angle

you talking of FCS (where shots fall)  when I am concerned of gun staying on target  recardles own vehicle movements 

 

 

Gun only needs to be stabilized on Pitch angle to gun to have good stabilization if the stabilization gyro is on turret?   Weapon roll would be like like  what is said in aviation to be aileron roll?   Or on picture below  ROLL axis.  While I am concerned of Weapons  Pitch axis  stabilization.

 

 

So yeah if there is no cant correction that would affect FCS system when firing on unlevel surfaces, but not affect on stabilization of gun staying on target right?   Because from this picture above.. 

 

So If we assume turret / weapon as centerpoint..   

- Yaw axis is basically one that keeps turret stabilized as happens already.   what clearly works.  

- Roll axis, as I understand is what you mean with =  CANT control?  "turret/weapon roll angle (=cant correction)."   would be like this in picture - relation to weapon right?    So missing that wouldn't really affect weapon stabilization? It would affect where your shots land, if you fire enemies when you have some roll angle, because your system wouldn't know direction of gravity.

- Pitch axis is what I am concerned about..     because currently pitch axis...   well if you imagine this plane (hull) having a turret..   pitch axis on cv9040 is on  that plane (hull)  not on it's turret.. so when you turn that imaginary turret of plane (hull) to side... you have rabitly dimishing if any weapon / or turret pitch axis stabilization anymore because location of pitch axis detector is not in turret but in plane (hull).     

 

 

 

So not sure about the CV-90's but these are in reference to the Abrams Tank which the Cant is located in the Turret:

 

-Cant function is to detect any lateral tilt in the turret. It consists of a pendulum device. The upper end of the pendulum is attached to the wiper of a potentiometer which is connected as a voltage divider between a +15 and -15 VDC power supply. When the tank is level, the wiper is centered and the output is at ground potential. Any tilt to the turret causes the wiper to be displaced along the resistive element, varying the output voltage. It is powered and provides an input all the time in both series, in the M1A1 series the input is used when the tank is not in motion. In the M1A2 SEP the unit is a back-up to the POS/NAV unit and still only provides input when the tank is not in motion.

 

-Position/Navigation Unit - the POS/NAV system is a self-contained, three-Axis, navigation system which computes vehicle heading, velocity. The computed information is based on data from an odometer input and two inertial sensors assemblies contained within the POS/NAV. This data is used to calculate distance, direction and for Far Target Location. Pitch and Roll data is used to provide dynamic cant input in the fire control system. 

 

So not sure if the CV-90's Cant system is similar. But if so then it would have to use another subsystem to take over during the vehicle movement as the M1A2 SEP does. 

Edited March 28, 2021 by Assassin 7

[Ssnake]

4 hours ago, Assassin 7 said:

So not sure if the CV-90's Cant system is similar.

It's most decidedly not, because there is none.

[Lumituisku]

57 minutes ago, Ssnake said:

It's most decidedly not, because there is none.

 

@Ssnake Is there any other vehicles in the Steelbeast that do not have Cant system? Or that would be similar to CV-9040?

 

Leopard AS1, 

T-55,

T-62,

BMP-2,

Bradley M2A2 ODS,

Pirantha FUS with Arrows weaponstation,

Aslaw 25.

 

Maybe one of these listed above or all of these?     I wonder, what sets these apart from the rest, and CV9040 apart from these?    Could it be that those in list lack CANT correction?   

Edited March 28, 2021 by Lumituisku

[Lumituisku]

I am starting to feel quite sure... that  

 

1 hour ago, Lumituisku said:

Leopard AS1, 

T-55,

T-62,

BMP-2,

Bradley M2A2 ODS,

Pirantha FUS with Arrows weaponstation,

Aslaw 25.  

 

Those vehicles listed above... don't have CANT correction, and hence bumpy terrain makes it very difficult gunnery for these vehicles listed.  

 

 

6 hours ago, Ssnake said:

If the gun is not stabilized against roll, driving on a bumpy road or on a strong incline will make for very difficult gunnry, just what you observe.

 

However point of this topic is that case with CV9040 is that unlike it, Vehicles above do have stabilisation regardless direction of where turret is pointing regarding to hull.  CV9040  is different... and much worse. 

 

I can see now how my topic naming has probably miss lead you to think this to be about cant correction, when it is not about that.   I think I can see now what you mean with cant correction and how you have implemented that on vehicles I listed above.  I may be wrong but I suspect that vehicles on that list do not have CANT correction and hence.. on those vehicles it seems that stabilization isn't always able to keep up on difficult terrain.   

 

If this is so, I think that how things are done on vehicles listed above is good, and such would indeed be more than satisfactory for cv9040  in my opinion.  

 

If you have not already checked how cv9040 differs from vehicles listed above when turret is turned to 90 degree right/ left   versus direct front you will find following.    

 

On a bumpy terrain

- Stabilization on vehicles listed above will behave same regardless of what direction turret is facing 

- Stabilization of CV9040 is far better on direct precice front, but extremely rabidly dimishes when turret is turned to right or left and on 90 degree if not soone stops existing.  There is no difference with or without stabilization on 90 degree angle.     

 

ALL THIS is easy to test.

On cv9040, just hold P key  when gun is pointing vehicle front, and you will notice difference.  Then turn turret to 90 degree side, and observe if there is any difference.  

On any of above vehicles... though I recommend T55 where  hitting dot  will turn stabilisation off.   Try looking at front with and without stabization and then to 90 degreee to side and observe difference. 

 

I did that same on the first video of this topic, and hence the tittle of this topic, that I though ough to have been clear enough.

 

For some reason... CV9040 behaves different to vehicles I listed.  Or maybe it should behave different?  I do not know...  but I am more than certain that the way how it behaves currently is so wrong that it ough to be corrected.  

 

 

I am sorry that this has been such a grinding discussion, I sincerely hope that we will be able to make sense of this one way or other.  

 

I will try to get better at conveying messages so that those would be easier to understand.  These missunderstandings are really tiring and exhausting. 

 

Thank you for your replies and patience Esimgames

 

 

[Ssnake]

To the best of my knowledge, all the fire control systems you listed but the CV90/40's have cant correction implemented. Which explains why this one fares worse with the turret oriented off to one side while on the move. That's what I've been trying to say all along.

[Rotareneg]

Just to toss a wrench into the mess... I just tested the CV90/40 in 4.250 and it does automatically correct for cant, so something is definitely wrong if it's not supposed to do that. I'll get a video up in a moment.

[Rotareneg]

Here's a video comparing the CV90/40 vs a M60A3 with and without cant correction enabled:

 

 

[Lumituisku]

😵 -> 🤯

 

 

54 minutes ago, Rotareneg said:

Just to toss a wrench into the mess... I just tested the CV90/40 in 4.250 and it does automatically correct for cant, so something is definitely wrong if it's not supposed to do that. I'll get a video up in a moment.

 

 

I am curious. Is there any difference if turret is rotated 45 or 90 degree angle to hull when firing?   

 

 

1 hour ago, Ssnake said:

To the best of my knowledge, all the fire control systems you listed but the CV90/40's have cant correction implemented. Which explains why this one fares worse with the turret oriented off to one side while on the move. That's what I've been trying to say all along.

 

Okay, Thank you Sir.  -   I am sorry but I have feeling that something is still profoundly wrong in CV9040, it doesn't behave in a way that I would understand it to do even without CANT correction unless gun stabilization point on real vehicle is fixed on hull front instead of turret front.  

[Rotareneg]

Just checked and it works at any angle. Attached is the test scenario and map I was using, it's got a raised road to test cant correction and a strip of bumpy terrain for checking stabilization.

Stab-Cant test.7z

[Lumituisku]

6 minutes ago, Rotareneg said:

Just checked and it works at any angle. Attached is the test scenario and map I was using, it's got a raised road to test cant correction and a strip of bumpy terrain for checking stabization.

 

Thank you very much Rotar.   I would not have though to test this.   

 

 

 

 

[Ssnake]

Hmmmmmmmm...

 

 

 

There may be two different issues at play here; it's now registered as bug #9671.

[RomeoNovember12]

As I understand your post above Ssnake this is being looked into?

 

It is true that the sight is only stabilized in "pitch" and "yaw". The FCS handles "roll" through a magnetic sensor that measures the earth's magnetic field.

 

The behavior of the CV9040 in SB right now is very far from reality. "Yaw"-stabilization works just fine and "pitch" is fine straight ahead but gets worse as you approach 3 and 9 o'clock as has been pointed out in this thread. This is not correct.

 

What you seem to have gotten wrong is that when the turret is at 3 or 9 o'clock the "pitch" stabilization handles the "roll" of the vehicle. Think of it as you are looking through the barrel. Up and down and sideways-motion of the vehicle is always handled by the gyros. It does not matter where the turret or gun is pointed. (Actually, the sight is stabilized and the gun just tries to keep up!) Rotation, "roll" or "cant" as in tilting your head right or left is handled by the magnetic sensor.

[Ssnake]

It seems like the CV90/40 received a fire control system upgrade after we implemented it for the Swedish Army. So it may reflect how it was some 15 years ago.

[RomeoNovember12]

The only FCS mod worth mentioning for the CV9040B/C since their introduction around 2000 is which laser-return is displayed first, furthest or closest. I don’t remember when that changed but SB is wrong there also, but it’s no biggie. It’s nostalgia for me.

 

Right now the Bs are being modified to become Ds with more changes. But nothing in regards to actual gun-laying as I understand it. They will be capable to salvo APFSDS though.

 

However the stab of the A/B/C has never been like the implementation in SB. I know it being a user of all versions since 2002.

[Ssnake]

...which is why it's registered as a bug, #9671, since March 2021.

[RomeoNovember12]

Any progress on #9671?