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Unstabilized Sights And Motion Sickness


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I been playing around in Steel Beasts, especially with the older AFV's modeled in the game. One thing I quickly noticed is when moving across country in older AFV's with no stabilization for the gunnery sights, start feeling motion sickness pretty rapidly. How did / do gunners utilize non stabilized sights to minimize motion sickness? Is it even an issue in real life?

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During most of my unit's training we would run with stab off. Motion sickness was never an issue for me.

 

When I got to my first unit my crew mates insisted that I be the gunner. I agreed so long as they understood that's where I would be during gunnery.

They never complained.

 

The only guy, an E-5, that I had to deal with that claimed motion sickness did it less than five minutes into a road march around Bergen-Hohne. I ignored him as he was a complete douche.

Edited by Tim Sielbeck
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Rule number one during tactical training and exercise: full stab ON. Always, always... As principle.

 

Motion sickness was not really a problem. Yea, I was as platoon and company leader also tank commander. And the russian sights for T-55/72 tc's are not stabilized. No problem yet.

 

Best LOS stabilization - eye/brain connection...

Edited by Stefan Kotsch
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I been playing around in Steel Beasts, especially with the older AFV's modeled in the game. One thing I quickly noticed is when moving across country in older AFV's with no stabilization for the gunnery sights, start feeling motion sickness pretty rapidly. How did / do gunners utilize non stabilized sights to minimize motion sickness? Is it even an issue in real life?

 

Some people had it in real life too (we had rubber boots as the sole therapy for that). I'm not suffering from it in SB, nor did I ever had the issue more than a slight whiff of nausea back in the days. I suppose, if you had it severely, you'd seek transfer out of the tank corps, or got promoted to commander or loader, at which point you get both fresh air and a much larger field of view.

 

In short, it's somewhat realistic but not everybody suffers from it in a similar degree. You may be one of the unlucky ones.

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I been playing around in Steel Beasts, especially with the older AFV's modeled in the game. One thing I quickly noticed is when moving across country in older AFV's with no stabilization for the gunnery sights, start feeling motion sickness pretty rapidly. How did / do gunners utilize non stabilized sights to minimize motion sickness? Is it even an issue in real life?

Much like sailors on the seas, and astronauts floating around in space, your brain gets used to the disconnect between the signals from your inner ear and your eyes.

On a related note, the M1 tank driver simulators came equipped with AC, fans, and a pocket for barf bags. The AC and fans were to keep the student driver cooled down to help alleviate the onset of motion sickness. The barf bags were available if the AC and fans weren't enough.

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Rule number one during tactical training and exercise: full stab ON. Always, always... As principle.

 

Wouldn't that wear out the stabilizer unnecessarily?

 

You might be interested to learn that for the M1 stabilization is the default "Normal" mode. A crew has to decide not to use stabilization by selecting "Emergency" mode. I'd be surprised if there are modern tanks with modern fire control systems that don't follow a similar pattern.

Edited by DKTanker
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Rule number one during tactical training and exercise: full stab ON. Always, always... As principle.

 

Wouldn't that wear out the stabilizer unnecessarily?

You might be interested to learn that for the M1 stabilization is the default "Normal" mode. A crew has to decide not to use stabilization by selecting "Emergency" mode. I'd be surprised if there are modern tanks with modern fire control systems that don't follow a similar pattern.

Well yeah, since turning on the stabilizer on the T-72 takes 2 minutes (mainly just waiting for the gyros to spin up), it should always be in full stabilization mode unless you're completely sure that you won't be shooting at anything in the near future. But *always* having them on seems a bit excessive.

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Rule number one during tactical training and exercise: full stab ON. Always, always... As principle.

 

Wouldn't that wear out the stabilizer unnecessarily?

You might be interested to learn that for the M1 stabilization is the default "Normal" mode. A crew has to decide not to use stabilization by selecting "Emergency" mode. I'd be surprised if there are modern tanks with modern fire control systems that don't follow a similar pattern.

Well yeah, since turning on the stabilizer on the T-72 takes 2 minutes (mainly just waiting for the gyros to spin up), it should always be in full stabilization mode unless you're completely sure that you won't be shooting at anything in the near future. But *always* having them on seems a bit excessive.

 

I know very little about the T-72, but I am surprised to learn it takes so long to get the gyros up to speed. I'm surprised because the M1 has no gyroscopes, and never did. The sight is stabilized through the use of resolvers, the gun is then electronically connected to the sights using resolvers in the hull, on the gun trunnions, and on the turret ring, to keep the gun aligned with the sight.

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Does the sight do edge analysis of the target in the sight once it's been acquired? Otherwise the gun and turret would just stay fixed and not stable relative to motion of the tank?

Edited by rmgill
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Does the sight do edge analysis of the target in the sight once it's been acquired? Otherwise the gun and turret would just stay fixed and not stable relative to motion of the tank?

Well, things have changed in the last 25 years since last I tanked, evidently the thermal system can now track targets, but I digress. As it was when I did tank, the gunner would simply keep the reticle on the object/target and the resolvers would note the point in space and keep the reticle, turret, and gun aligned with that point in space. Caveat, this only happened when the gunner or TC engaged the control handles. If one or the other wasn't actively using the control handles the stabilization was off. Depress the palm switches, stab on. Release the palm switches, stab off. Note, it was the gunner that kept the reticle on target, not the stab system.

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I been playing around in Steel Beasts, especially with the older AFV's modeled in the game. One thing I quickly noticed is when moving across country in older AFV's with no stabilization for the gunnery sights, start feeling motion sickness pretty rapidly. How did / do gunners utilize non stabilized sights to minimize motion sickness? Is it even an issue in real life?

Much like sailors on the seas, and astronauts floating around in space, your brain gets used to the disconnect between the signals from your inner ear and your eyes.

On a related note, the M1 tank driver simulators came equipped with AC, fans, and a pocket for barf bags. The AC and fans were to keep the student driver cooled down to help alleviate the onset of motion sickness. The barf bags were available if the AC and fans weren't enough.

 

I'm glad you mentioned that, I was going to post that during the Ft Knox I&I I did get nauseous in the driving simulator.

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I know very little about the T-72, but I am surprised to learn it takes so long to get the gyros up to speed. I'm surprised because the M1 has no gyroscopes, and never did. The sight is stabilized through the use of resolvers, the gun is then electronically connected to the sights using resolvers in the hull, on the gun trunnions, and on the turret ring, to keep the gun aligned with the sight.

Sorry but that is literally not possible.

 

Edit: to elaborate, the resolvers must be using a gyroscope as a reference point to detect deviations.

Edited by Interlinked
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The very first time I rode in an M60A3 gunner's seat at Fort Knox, I felt a little queasy for a few minutes but it quickly passed. It reminded me of getting nauseous the first time I flew in an airplane.

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Well, things have changed in the last 25 years since last I tanked, evidently the thermal system can now track targets, but I digress. As it was when I did tank, the gunner would simply keep the reticle on the object/target and the resolvers would note the point in space and keep the reticle, turret, and gun aligned with that point in space. Caveat, this only happened when the gunner or TC engaged the control handles. If one or the other wasn't actively using the control handles the stabilization was off. Depress the palm switches, stab on. Release the palm switches, stab off. Note, it was the gunner that kept the reticle on target, not the stab system.

So absent corrections by the gunner (or commander) to keep the cross hairs on the target the system will not adjust elevation/traverse of the gun (or of the reticle) to keep it aligned with what the gunner is seeing vis a vis a target.

 

In essence the gunner is steering the reticle and the stab system is aligning the gun to that?

 

Edit: to elaborate, the resolvers must be using a gyroscope as a reference point to detect deviations.

If the key thing is angular differences between where the reticle is pointing and where the gun is pointing, there's just a relative difference between rotary encoders, no need for the gyro to measure relative earth position, angle position sensors do probably factor in as part of the math for the gunnery though.

Edited by rmgill
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Gyro's must come up to speed and stabilize onto a direction. On a ship gyrocompasses are not considered reliable for at least an hour.

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Edit: to elaborate, the resolvers must be using a gyroscope as a reference point to detect deviations.

If the key thing is angular differences between where the reticle is pointing and where the gun is pointing, there's just a relative difference between rotary encoders, no need for the gyro to measure relative earth position, angle position sensors do probably factor in as part of the math for the gunnery though.

Stefan wrote quite a bit about the stabilizer of the Abrams: http://www.kotsch88.de/stabi-m1a1.htm

 

It uses multiple gyros for the independent stabilization of the gun and the sights.

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So absent corrections by the gunner (or commander) to keep the cross hairs on the target the system will not adjust elevation/traverse of the gun (or of the reticle) to keep it aligned with what the gunner is seeing vis a vis a target.

 

In essence the gunner is steering the reticle and the stab system is aligning the gun to that?

 

Most FCS have movement correction to fire on the move and fire on moving target. To enable it gunner is required to keep reticle on target for some time, then angular speeds are noted and taken to automation. Modern ones have digital visual target tracking, which is obviously better cuz not affected by change of speed and direction.

If that's what you meant.

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I would be surprised if the Abrams uses actual spinning gyros. Laser ring gyros have been around for more than 30 years, and MEMS "gyros" for quite a while, too.

Problem is M1 appeared quite a bit more than 30 years ago... So I wouldn't bet for early versions to be too sassy in that regard.
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I'm not sure why you think this is a pissing contest. I merely pointed out that alternatives were possible. Not to mention that the Abrams is notably not the machine it was when it had a 105mm.

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A bit of a search finds that the currently selected gyro is a G-2000 series from Northrop Grumman. Its design appears to be fairly traditional. It's a rate sensor with low drift rate and spins up in 1.4 to 3 seconds.

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In essence the gunner is steering the reticle and the stab system is aligning the gun to that?

Gunnerys primary sight has the primary stabilization. And turret and gun follow with their secondary stabilization "afterwards". Yes, the gunner leads the sight, the weapons follow.

And primary and secondary stabilization measure the deviation from the zero position with gyros - and the resolvers thereof generate an electrical signal for the stabilization electronics.

 

(Maybe the cause of the misunderstanding. The mirror head of the M1A1 has been gyro-stabilized only vertically.)

Edited by Stefan Kotsch
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A bit of a search finds that the currently selected gyro is a G-2000 series from Northrop Grumman. Its design appears to be fairly traditional. It's a rate sensor with low drift rate and spins up in 1.4 to 3 seconds.

Perhaps hidden away from the crew and 1st level maintainers insofar as interface and usability is concerned?

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