[sci.military] Power Armor

nanis@llex.ll.mit.edu ( Jeff Nanis) (05/24/91)

From: nanis@llex.ll.mit.edu ( Jeff Nanis)


camelsho@matt.ksu.ksu.edu (James Seymour) writes:
>When queried, he ran off a whole list of stuff:  5 lbs 
>personal airconditioners (7 lbs if you want filtration), 
>layered Kevlar armors, reactive armors, heads up displays,
>integrated circuits, modular systems, power augmentation
>for hadicapped that run on neural inputs that funcion much
>like orginal limbs, hand/shoulder held/fired antitank weapons,
>etc.  

>	[Who's going to do the maintenaince on all that? --CDR]

	Contractors, like the 4000+ who maintained all the high-tech
toys in Desert Shindig. How else do you think things like the Apache
were able to achieve >98% availability rates? It's interesting to
look at the growth of contractor support during operational/combat
employment over the last 50 years. Much of the early days of EW
(up through Vietnam), the "electronic warriors" were civilans -
DoD employees or contractors. Although that particular function has
been hard-wired into the system a little bit, things like depot-level
maintenance are still handled by civilian professionals with many more
years experience than an E-6 whose been rotated around two or three
times in his 8 years of service.

	Currently CVs have more than a hundred contractors for support 
at all times. Does the future hold an increase in this trend? 

--
Jeff Nanis                               Radars 'r' us.  
nanis@ll.mit.edu                         An official opinion? Not on my life. 

henry@zoo.toronto.edu (Henry Spencer) (05/25/91)

From: henry@zoo.toronto.edu (Henry Spencer)


>From: camelsho@matt.ksu.ksu.edu (James Seymour)
>...contention that we are near the tech level needed for [Powered Armor]

There are a couple of crucial shortfalls in our current technology, I think.

One is the need for force-feedback technology for effective control.
We will see powered armor after, not before, we have high-quality
"waldos", robot arms that follow the motions of a separate human
operator.  Current waldos are decidedly crude, and in particular do not
give the operator any tactile feedback on what's going on at the other
end.  Worse, there is little work being done on improving them.

Second is the sheer mass of both the necessary motors and the necessary
power source.  Portable energy-storage systems have pitifully small
energy capacities for their mass.  I'd guess you would end up with some
sort of fuel-burning engine (baby gas turbine?) driving a hydraulic
pump.  Batteries are hopeless; don't expect battery-operated powered
armor until electric cars are plentiful and perform well.  The motor
situation is improving, but energy storage isn't, much.

>What real use would PA have in combat? 

I think this is the real question.  Its advantages will be minimal
unless it's good enough armor to make it just about invulnerable to
well-equipped infantry.  Otherwise it is cheaper and simpler to just
field more infantry.  Considering rifles, heavy machine guns, grenades,
and the smaller shoulder- launched missiles, that level of protection
is a tall order.  You can't assume that the armored soldier has
superior weapons, because it will be easy to equip infantry with the
same weapons -- the infantry won't find them as easy to carry, but
there will be lots more infantrymen to carry them, and the infantry is
used to doing pack-mule duty :-).  One possible exception is if the
armored soldiers make heavy use of chemical and biological weaponry,
since they'll have a much easier time carrying full life support and
adequate cooling.

-- 
And the bean-counter replied,           | Henry Spencer @ U of Toronto Zoology
"beans are more important".             |  henry@zoo.toronto.edu  utzoo!henry

abennett@athena.mit.edu (Andrew Bennett) (05/25/91)

From: abennett@athena.mit.edu (Andrew Bennett)


> If we really wanted to, could we actually produce effective
> PA?  If not, what advances still have to be made and what is
> the estimated time frame for developement of the respecive
> technologies to arrive?
> 
> What real use would PA have in combat?  Would they be a cost
> effective alternative to convential weapons?  

A quickie estimate (backgrtound - I've had about a year of
robotice/man-amplifier systems experience, as well as about 3 years of
weapons design).

PA requires three main features:  a dense, long-lasting power supply, a
robust control/feedback system to manuver it, and a reason to build it.

1) Power supply - you need enough power to keep the systems running for
a few hours if you want to make it worthwhile (a suit that only runs
for an hour or two between refuelings isn't going to be able to range
very far afield).  Figuring that it has to propel the user quickly (to
avoid being a target), carry a considerable weight in weapons, air
conditioning/purifying systems, radiation hardening (optional),
shock-proofing (otherwise a near miss is as good as a hit), and
supplies (water is probably the most important), it is going to need a
very dense, relatively light power source.  That means some form of
combustion like an internal combustion engine or turbine system
(possibly, some new form of fuel cell might work, too).  All of these
tend to get large quickly.

2) Control system - It has to be able to balance as well as a human, or
at least offer feedback good enough for the human's sense of balance to
work.  Either way, that's a lot of real-time processing and sensing
going on.  So, figure each suit requires a processor in the 10-100's of
mflops, maybe more.  Add to that the threat sensing, target acquisition
systems and whatever other targeting/weapons goodies you want, and the
total processor is definitely not a trivial device.

3) Reason to build it - What does PA offer to make it worthwhile?  It
will definitely be an expensive proposition to build it.  You'll need
the latest in strong, light technologies for it, and those aren't cheap
(see: B-2).  You'll also need state of the art computer and sensing
systems, their accompanying software, and all of it has to be robust
and *very* reliable.  In return, the PA offers a smaller, more nimble
target than a tank.  That, unfortunately, is about it.  The economics
tend to point away from such a device.  Think of it this way:  you
generally don't use a weapons system against a target unless the return
on your efforts is greater than the loss if you lose your weapon.
i.e.  you don't attack individual tanks with cruise missiles (unless
it's one **** of a dangerous tank), since the effort to produce the
missile is much greater to you than the loss of the tank would be to
the other side.  So, you'd only employ PA against very valuable
targets.

BUT, if they're valuable, then they're probably well defended.  In that
case, why risk trained soldiers when an automaton (smart bomb, cruise
missile, etc.) may do the job just as well (and cheaper)?

3a) Tactical consideration - PA has one operator, so he/she has to do
*everything*: maneuver, targeting, threat monitoring, etc.  This can quickly
become overwhelming.  So, you'll have to develop even *better* sensing/warning
systems to help.  More cost, sigh.

Finally, for the cost of the PA, the other side may deploy a swarm of
infantry with small missiles.  They can afford more losses then the PA
side can (much like your PA vs. tank scenario in the original
posting).

Summary:  I don't think it's worth the $$.  Sorry.

--
Andrew Bennett             MIT Network Services                 abennett@mit.edu
MIT Room 11-124H                                   abennett%athena@mitvma.bitnet
77 Massachusetts Ave.                                      Phone: (617) 253-7174
Cambridge, MA  02139                                <Standard disclaimers apply>

fcrary@headcrash.Berkeley.EDU (Frank Crary) (05/25/91)

From: fcrary@headcrash.Berkeley.EDU (Frank Crary)


camelsho@matt.ksu.ksu.edu (James Seymour) writes:
>When queried, he ran off a whole list of stuff:  5 lbs 
>personal airconditioners (7 lbs if you want filtration), 
>layered Kevlar armors, reactive armors, heads up displays,
>integrated circuits, modular systems, power augmentation
>for hadicapped that run on neural inputs that funcion much
>like orginal limbs, hand/shoulder held/fired antitank weapons, etc. 

I think you friend's numbers are somewhat low. I know the all the
required systems except "power augmentation" can be built today. In
fact, there is a guy at NASA/Ames building one right now (he calls it a
"Hard Space Suit" and has not considered any military applications...)
From the numbers I have seen, a closed-loop air supply (e.g. full CBW
gear) and cooling systems, together with the armor itself, would weigh
about 75 to 150 kg. Most of it could, as I suggested above, be taken
from space suit design, including the armor. The Hard Space Suit I
mentioned above has been tested to withstand damage from micrometeors.
They fired 0.1mm projectiles at the suit at up to 10,000 m/s. What sort
of armor this is equivilent to, I'm not exactly sure.

>Royal even postulized that it might be possible to field
>20 or more PA equiped troops for the cost of normal armored
>vehicles.

I rather doubt these cost figures.

>What real use would PA have in combat?  Would they be a cost
>effective alternative to convential weapons?  

There are two big advantages I could see. First, with some sort of
"power agumentation" an infantryman could carry more and better weapons.
Second, he would be much more survivable in combat. HE and anti-personel 
weapons would be as deadly. Infantry Fighting Vehicles (such as the M-2
Bradley) are intended to do this, but as long as the infantry is safe,
they are also much less effective (e.g. they can't fight well from a
IFV). This would not be a problem for infantry in "power armor"

Frank Crary

nak%archie@att.att.com (Neil A Kirby) (05/30/91)

From: nak%archie@att.att.com (Neil A Kirby)


fcrary@headcrash.Berkeley.EDU (Frank Crary) writes:
>I think you friend's numbers are somewhat low. I know the all the
>required systems except "power augmentation" can be built today. In
>fact, there is a guy at NASA/Ames building one right now (he calls it a
>"Hard Space Suit" and has not considered any military applications...)
[rest deleted]

Power augmentation is required for a 1G environ.  It's the one thing you
cite as lacking, and on earth it's the most important (possibly tied with
feedback/control to go with it).  Space suits live in 0g.  Walking a 75-150
kg (your numbers, deleted above) suit around would be too taxing for a
human powered suit.

Neil Kirby

gary@gatech.edu (Gary Coffman) (05/31/91)

From: ke4zv!gary@gatech.edu (Gary Coffman)


camelsho@matt.ksu.ksu.edu (James Seymour) writes:
>If we really wanted to, could we actually produce effective
>[Power Armor]?  If not, what advances still have to be made and what is
>the estimated time frame for developement of the respecive
>technologies to arrive?

The two major blocking technologies keeping PA from deployment are
power packs and neural/force actuator technology.

Current laboratory experiments with neural control still result in
shakey control after elaborate training/tuning and must be custom fit
to the individual and retuned if the individual's emotional state changes.

Force sensor/amplifier/actuator technology is closer to reality, but
still requires elaborate custom fitting and training to be effective.

Application of DSP and AI techniques may make both control methods
feasible in the fairly near term (<20 years). Considerable
training/conditioning will likely still be required. This training
would be akin to athletic training for complex neuro-motor sports.

There are no current power pack designs that can supply the necessary
power for reasonable amounts of time and still be carried, even by an
augmented man. New battery and fuel cell designs are in the lab that
might work for fairly short missions, but cracking the 24 hr unrefueled
barrier is going to be tough.

>What real use would PA have in combat?  Would they be a cost
>effective alternative to convential weapons?  

If the refueling problem can be licked, they'd make ideal long range
patrol forces. With current sensor technology, they'd be good jungle
warfare troops. Their uses on urban battlefields should be obvious.
Use in an open enviornment where tank killers have field days wouldn't
be so good. They'd still be slower, less well armed, and less well
armored than real tanks. The primary advantages of PA are the enchanced
sensors (nearly real today), body armor against light weapons (again
nearly real), heavier weapons (nearly real), and the ability to quickly
move that load anywhere a man can walk or crawl on the battlefield
(this isn't real yet).

>Hey, is someone already working on PA?  What is the progress so far?

I'm only aware of some Army experiments nearly 20 years ago with
powered exoskeletons. The control technologies weren't up to the task
then. They may be soon. The design goal was a man who could run, climb,
and crawl at least as well as an unagumented man while carrying the
heavy armor, armaments, and sensors envisioned. Ideally, a top burst
speed of 35 mph was desired. What was achieved was a slow walking pace
of 3 mph and poor agility. Control technology has advanced dramatically
since then, I have no information on current attempts to build PA.

Gary

fcrary@lightning.Berkeley.EDU (Frank Crary) (06/10/91)

From: fcrary@lightning.Berkeley.EDU (Frank Crary)


ke4zv!gary@gatech.edu (Gary Coffman) writes:
>There are no current power pack designs that can supply the necessary
>power for reasonable amounts of time and still be carried, even by an
>augmented man. New battery and fuel cell designs are in the lab that
>might work for fairly short missions, but cracking the 24 hr unrefueled
>barrier is going to be tough.

This is not the case. Moving around a 100-kg suit should be roughly the
maximum power output of a human (E.g. doing this by your self would be
the most one could do, but not impossible. Note I said power NOT
force.) Using this as a guess as to power requirments, this implies a 2
kW, or roughly 3 horsepower output. Allowing for efficiencies, I can't
see such a suit requiring more than 10 hp. Are you saying that a 10 hp
motor is too big?

Frank Crary

bsercomb@gara.une.oz.au (Katani) (06/12/91)

From: bsercomb@gara.une.oz.au (Katani)


> maximum power output of a human (E.g. doing this by your self would be
> the most one could do, but not impossible. Note I said power NOT
> force.) Using this as a guess as to power requirments, this implies a 2
> kW, or roughly 3 horsepower output. Allowing for efficiencies, I can't
> see such a suit requiring more than 10 hp. Are you saying that a 10 hp
> motor is too big?

the original idea was for the suit to be completely self powered,
carrying a fuel payload for about 1week+, having optical/detection
enhancement and weapons. The weapons can be carried on the body or in
the hands.

Integrating such a piece of technology is a tough chore. The optics
have to be independant of the movement processing hence 2 computers.
Next, how big are the assisting units [which supply power to the
skeleton]??

gary@gatech.edu (Gary Coffman) (06/13/91)

From: ke4zv!gary@gatech.edu (Gary Coffman)


fcrary@lightning.Berkeley.EDU (Frank Crary) writes:
>kW, or roughly 3 horsepower output. Allowing for efficiencies, I can't
>see such a suit requiring more than 10 hp. Are you saying that a 10 hp
>motor is too big?

No, the motors, or force actuators, are really quite small and light
nowadays. Supplying more than 6 kw for 24 hours to run the motors is
the problem. Note that your power estimates are based on a human just
barely carrying a suit. What is required is a suit that can exhibit the
speed and agility of an unencumbered man or better while carrying
relatively heavy weapons and perhaps even having the strength to bash
heavy doors or tip a jeep. In addition to power for movement, power is
needed to operate the sensor and control system and to supply
enviornmental conditioning for the occupant. Some weapon systems, for
example an electrically operated minigun, would require power as well.
That implies higher power figures than you quote. I'd guess more like
15 to 20 kw peak. Even a 6 kw peak system that can supply 144 kwh
without refueling is not small or light.  A further constraint is that
the power generation be quiet and have a low IR signature.  A screaming
gas turbine would negate much of the stealth advantage of PA.  Nearly
all the technologies to build PA are available or expected in the near
term. The power supply problem is the major stumbling block.

Whether PA is really militarily useful is another question. With the
occupant buttoned up for NBC protection, with a sensor system capable
of working in low light, low sound level, low olifactory level, radar,
lidar, and god knows what else, with protection against most light
weapons, with fairly heavy offensive weapons, and the agility of an
unencumbered man to walk, run, crawl, crouch, or fight, PA would be
a formidable tool on the urban battlefield. Slipping through the
jungle with the enhanced senses provided by PA, it would be a formidable
jungle fighting tool. Sauntering across an open tank killing ground,
it would be suicide.

Gary

phil@brahms.AMD.COM (Phil Ngai) (06/15/91)

From: phil@brahms.AMD.COM (Phil Ngai)


ke4zv!gary@gatech.edu (Gary Coffman) writes:
>Whether PA is really militarily useful is another question. With the
>occupant buttoned up for NBC protection, with a sensor system capable
>of working in low light, low sound level, low olifactory level, radar,
>lidar, and god knows what else, with protection against most light
>weapons, with fairly heavy offensive weapons, and the agility of an
>unencumbered man to walk, run, crawl, crouch, or fight, PA would be
>a formidable tool on the urban battlefield. Slipping through the
>jungle with the enhanced senses provided by PA, it would be a formidable
>jungle fighting tool.

Hm, I wonder how much this thing would weigh and how big its feet would
be. Could it swim? Cross a rice paddy? What if you spent the money
instead on rifles and cheap drafted soldiers? I'm not sure how this
thing could really be economic.

Or even more effective, a squad of soldiers with radios calling in
air dropped smart weapons. This idea of armor seems of limited value.
A dozen soldiers with machine guns ought to be able to hose up the
PA's sensors pretty well. The only value I see to PA is the ability
to carry more than a human can. Well, airplanes can do that too.

gary@gatech.edu (Gary Coffman) (06/24/91)

From: ke4zv!gary@gatech.edu (Gary Coffman)

In article <1991Jun18.074541.15334@amd.com> phil@brahms.AMD.COM (Phil Ngai) writes:
>
>Hm, I wonder how much this thing would weigh and how big its feet would
>be. Could it swim? Cross a rice paddy? What if you spent the money
>instead on rifles and cheap drafted soldiers? I'm not sure how this
>thing could really be economic.

A guestimate on weight would be around 150 kilos depending on the
weight of the problematic power supply and it's fuel. Since the
suit would be capable of operating totally buttoned up for NBC
protection, it could simply walk across the bottom of rivers, and
need not be able to swim. I doubt it would float, but it might
be able to swim if necessary. A number 12 shoe should be big
enough to have about the same ground loading as a normal man.

As to it's value versus cannon fodder, US doctrine has lately
been to expend money on high tech rather than accept high
casualty rates. The Chinese might have a different perspective.

>Or even more effective, a squad of soldiers with radios calling in
>air dropped smart weapons. This idea of armor seems of limited value.
>A dozen soldiers with machine guns ought to be able to hose up the
>PA's sensors pretty well. The only value I see to PA is the ability
>to carry more than a human can. Well, airplanes can do that too.

Airplanes aren't very good at house to house fighting in civilian
neighborhoods. And you never seem to be able to find air support
when you need it. The fly boys always seem to want to go off
chasing other airplanes, or somebody with more rank wants *their*
anthill smashed first. The advantage granted by the sensor net
is that you would know about those dozen soldiers before they
knew about you granting you the advantage of surprise or evasion.
In most cases in Vietnam, jungle ambushes were over long before
air power could be brought into play.

Gary

kash1@cs.aukuni.ac.nz (Kemp Ashby) (06/27/91)

From: kash1@cs.aukuni.ac.nz(Kemp Ashby)
In <1991Jun18.074541.15334@amd.com> phil@brahms.AMD.COM (Phil Ngai) writes:

>Hm, I wonder how much this thing would weigh and how big its feet would
>be. Could it swim? Cross a rice paddy? What if you spent the money
>instead on rifles and cheap drafted soldiers? I'm not sure how this
>thing could really be economic.

Generally, I agree. However, don't forget that the 'Quantity beats Quality'
argument was somewhat disproved in the gulf, though I appreciate that the
scales are different. Also PA would obviously be more effective in some
settings than others.

>Or even more effective, a squad of soldiers with radios calling in
>air dropped smart weapons. This idea of armor seems of limited value.

Yes, but that means that you need to have at your disposal a large number
of aircraft to target a possibly highly mobile enemy - this doesn't sound
very economic either.

>A dozen soldiers with machine guns ought to be able to hose up the
>PA's sensors pretty well.

Assuming you can hit the target that accurately. How often in modern combat
would it be the case that a man-sized target can be hit often enough to be able
to hose off all of the (probably highly redundant) sensors? What if the range to
the PA is over a couple of hundred yards? Assuming you can even hit the target,
you'll need more powerful weapons than current assault rifles to have any
effect that far out, ie the 12 soldiers you speak of will have to carry
M60s or something - very tiring.
And its not very good for morale to know that you are facing a superior enemy,
even though there may be less of them.

sysmgr@KING.ENG.UMD.EDU (Doug Mohney) (06/29/91)

From: sysmgr@KING.ENG.UMD.EDU (Doug Mohney)
In article <1991Jun27.020204.3941@cbnews.cb.att.com>, kash1@cs.aukuni.ac.nz (Kemp Ashby) writes:
>>Or even more effective, a squad of soldiers with radios calling in
>>air dropped smart weapons. This idea of armor seems of limited value.
>
>Yes, but that means that you need to have at your disposal a large number
>of aircraft to target a possibly highly mobile enemy - this doesn't sound
>very economic either.

Why bother with that? SADARM munitions (Search And Destroy ARMor) are 
currently being fielded. Launchable by 155mm shell now, but the form factor is
such that you could fit it down a mortar tube. 

SADARM is about the size of a tomato can and fires a self-forging fragment
down into the engine compartment of a vehicle. Given current processor
advances, it would be easy enough to design a smart munition to find a PA-sized
target and punch a SFF through it.

The Merlin 81mm (?) mortar shell also is a smart weapon which could be reworked
to counter the PA threat should it evolve.


     Signature envy: quality of some people to put 24+ lines in their .sigs
  -- >                  SYSMGR@CADLAB.ENG.UMD.EDU                        < --