SYSTEME EN SALLE POUR LA SIMULATION DU TIR DE PROJECTILES BALISTIQUES

TOW INDOOR SIMULATOR

Abrégé anglais

ABSTRACT OF THE DISCLOSURE
An optical system adapted to be used in a guided weapon
training system having an effective live range and operative for exercising
a gunner. The weapon training system includes a conventional tracking head
and an instructor's console electrically connectible to a missile guidance
set. The latter is operative to generate an error signal which drives a
scoring mechanism to indicate a trainee's ability to track a target. The
optical system functions to reduce the effective range optically to a dis-
tance accommodated within a drill hall, building classroom or the like.
The optical system includes a lens assembly sightable on a miniaturized
live target along a visual line of sight, the optical system being remov-
ably securable to the tracking head of the weapon training system, enabling
conversion of the same for use indoors. An infrared source is used to
generate an IR signal from the target, with the optical system including
a corrective lens to remove parallax between the visual line of sight and
the IR signal path. In another embodiment, the IR source is a laser mounted
in close proximity to the weapon's system and operable to project a symbolic
target onto a target board, there being an adjustably movable reflecting
means also provided for moving the symbolic target across the target board.

Revendications

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An optical system for use in association with a guided weapon train-
ing set having a live range which optically reduces the live range to a
distance accommodated within a classroom or the like, said training set having
a tracking head including an IR detector and a telescopic sight, and an elec-
trically powered instructor's console connectible to a missile guidance set
for generating an error signal to drive a scoring mechanism indicative of a
trainee's ability to track a target, said optical system comprising,
a correcting lens aligned with said telescopic sight to remove
parallax between two parts of an incident light beam;
a beam splitter arranged between said correcting lens and said
telescopic sight to direct a first portion of an incident light beam transmit-
ted through said correcting lens and to transmit a second portion of said
incident light beam to said telescopic sight, said incident light beam inclu-
ding a visual and an IR component; and
a reflecting surface arranged in the path of said directed first
portion of the incident light beam to reflect said first portion to said IR
detector to generate said error signal.
2. An optical system according to claim 1, wherein said optical system
includes a box frame for mounting said correcting lens in alignment with an
eyepiece on the telescopic sight, said box frame including an aperture for
transmitting light and said box frame being fixedly secured to a base plate
that is itself removably attachable to the tracking head.
3. An optical system according to claim 2, wherein said beam splitter
is also supported by said box frame.
4. An optical system according to claim 1, 2 or 3, comprising bracket
means for supporting said reflecting surface in alignment with said IR detector,
including an aperture for transmitting the reflected first portion of the
incident light beam to said IR detector.

5. An optical system according to claim 1, 2 or 3, wherein target
means is provided having an IR source thereon, said target means being selec-
ted from a real miniature target and a projected image on a suitable screen.
6. An optical system adapted to be removably mounted on a tracking
head of a guided weapon training set having a live range which optically
reduces the live range to a distance accommodated within a classroom or the
like, said training set also including an IR detector and a telescopic sight
as part of said tracking head, an electrically powered instructor's console
connectible to a missile guidance set for generating an error signal to drive
a scoring mechanism indicating a trainee's ability to track a target; said
optical system comprising;
a base plate having means thereon for releasably attaching the
optical system to said tracking head,
a box frame having sides, a front side having an opening therein
for mounting a correcting lens to remove parallax between two parts of an
incident light beam and a rear side having an opening to mount a beam splitter
for directing a first portion of an incident light beam transmitted through
said correcting lens, and to transmit a second portion of said incident light
beam to said telescopic sight, said incident light beam including a visual
and an IR component, the correcting lens and beam splitter being in alignment
with the telescopic sight; and
bracket means for supporting a reflecting surface, said reflecting
surface being arranged in the path of said directed first portion of said inci-
dent light beam to reflect said portion to said IR detector to generate said
error signal.

Description

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T~iS il\Ve~ll iOII nelf3teS ~',(n(~r'al Iy to a ~/e,lP(Jrl~-J SySterll t,r-lirlirl,.g
clid. More l)articnl~r]y, ll~is ir~v(r~tion rel~t(s ~o a guide(l ,/eal~orl silmllator
intended to be ~Is~d in(loors.
Modcrn weal)oll sy~stellls incln(le Inclrly which re(luire regular
trainirly, arl(l exercisLng of artillery merl an(l gllnllers Ml this respect, it
is naturally importallt for an instr~lctor to be ~IbLe to evaL~Iate e.lcll trainees
progress Eor acc(lracy. This i~s especially true of glJided weapons that, for
example, may be automatically commanded/controlled to foLlow a gunners optical
or visual line of Sigllt to a target until impact. The probability of a hit
is increased if tracking of the target is done both accurately and smoothly
during the flight time of the missile or other guided weapon.
One particu]ar guided weapon simulator of the type with which
the present invention is to be used is the M-70 Training Set of the Hughes
Aircraft Company. The M-70 Training Set consists of a target board which is
mountable on any suitable vehicle, and of an instructorls console which is
electrically connected to a tube-launched optically-tracked wire guided
missile ~TOW) weapon system, used as a scoring mechanism. During training
sessions, the target board is located some 450 meters from the TOW launcher
and moved about. The trainee gunner tracks the center of the target board
for a predetermined period of time. The accuracy and smoothness of tracking
is measured by detecting an infrared (IR) signal derived from an IR source
mounted on the target board, and by developing the error or deviation between
the gunner's visual line of sight and the true position of the center of
the target as error signals. These error signals drive the scoring mechanism
of the instructor~s console to indicate the gunner~s ability to track the
target. It will be evident that the M~70 training set is designed for out-
door use and operations that require open firing range facilities.
The present invention provides a specific improvement to the
M-70 Training Set. This invention comprises means in the form of an optical
system for adapting the M-70 Trainer for use indoors in a classroorn setting
or other controlled environment. By means of the optical system to be
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aescrihed helc)w, the conven~ional M-7() Training Set is rendered usable in-
ck)c)rs in aclclition to iLs stanci.lr(l use outdoors. Tllus, essential training
can be provided to a TOW llunnel, witll each trainee receiving a permanent
record of his tracking capabilities alld progress, while givirlg an instructor
a realistic indication of hits and misses. lt wiLl be evk]ent that further
simulation o~ a target obsc~lred by smoke, trees or had lighting can be
implemented fairly readily.
Thus, by one aspect of this invention there is provided in a
;~ guided weapon training system having an effective live range and operative
for exercising a gunner, the training system including a tracking head and
an instructor's coosole electrically connectible to a missile guidance set
for generating an error signal to drive a scoring mechanism which indicates
a trainee~s ability to track a target, the improvement comprising an optical
system operable for reducing the effective range optically to a distance
accommodated within a drill hall, building classroom or the like, said
optical system being removably securable to said tracking head of the weapon
training system and including a lens assembly sightable along a visual line
~ of sight to a movable, mlniaturized llve target.
;~ Thus one aspect of the present invention is based on a real-
` 20 miniatur~ed target range~ The prototype described below uses a 4 meter fixed
focus installation. A miniature tank -target is moved on a track or path
located at the fixed focal length of the weapon simulator The target's move-
ment simulates motion of a real target selectively on a level or hilly terrain.
A foreground and background panoramic scene adds to the realism of the
simulation~ The gunner tracks the target and his ability is measured by
detecting infrared radiation emitted at an aiming point drawn on th~ miniature
target. Realism is thus llmited only by the amount of effort devoted to
building a model and scenery.
Another aspect of this invention is based on a target projection
system which presents a gunner trainee with an image of a target on a screen.
This image is to be tracked by the trainee and his ability to perform the
task is measured by detecting the reflection of an infrared beam that has
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~J~ve l o~ cl ~ r~ L~. r fi~ l irl.Y ~ i ()rl r ~ i r i.~ (JIJL i-,~
adal)L~r of tl~at f~ ng~ll, toyetller wit~ curve(l flcreen. Sllch arJ arrtJngr
merlt ha~; a(lv.llltag~s ol por~al)il iLy, r~lpi(l erectk~rl all(l flexibili~y of targe-
movemel-l t .
Tllcse arl(l o~ er f ef~l.Ur'('S Or th1s invr nL10rl Wi,L I l)ec()me nlore tapparent from tlle clescril)tlon below. Thàt degcrLption i~ to he read in con-
junction witll the accompanying drawings tllat illustrate hy ~/ay of exarnple
only certain features of the preferred embodiment of this invention.
In the drawings
FIGURE 1 is a schematic drawing showing in perspective one
form of the present invention as adapted for use with an M-70 Training Set;
FIGUR~ 2 is also a schematic drawing showing certain details
of an optical system adapted for use in the M-70 Training Set of Figure l;
and
FIGURE 3 is also a schematic view showing other details of
the optical systern of Figure 2.
In turning to Figure 1, a conventional M-70 Training Set is
shown overall at 10. The M-70 weapon is for delivery of a tube-launched
optically-tracked wired-guided(ToW) missile. The M-70 Training Set 10 is
itself manufactured by Hughes Aircraft Company and is described in detail
in U.S. Technical Manual TM 9-6920-470-12, as published by the United States
Deportment of the Army. Specific detail of the M-70 Training Set is beyond
the scope of this application and is not required for an understanding of
the present invention~ Very briefly, the M-70 Training Set cornprises a
tripod base 12, a traversing unit 14, a sighting and traclcing unit 16, a
launcher 18, an instructor~s console 20 and a power supply modulator 22.
Previously, i.e., in the prior art sense, the M-70 Training Set provided
hands-on experience with the weapon, giving realistic practice and training
experience, but requiring an outdoor range with a target located severaL
hundred meters away.
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T(~ ',rl"i!; nlOlll('rl~ar i Iy afld (~ r i b(' tllf' I)r ior "rL f llrlst iOflirig
of L11e M-7() Tr1ining 'i~t 1() in Lbe prior arl se~1se, Llle Lo11Owlr1g f~bo1l1(l be
consideredO A taruet normally Inourl~i(i on a vehicle pro~/i(Jed ;1 defi,lit( aiming
point ror the Lrairlee gul~ cr. 'I'l~i.s LargeL also provi(lec: an infrare(l ~;ignal
for c1etenni1li1lg Lhe ~rair1ee'u Lrackirlg ac(ur1cy~ Ll~ ra(li.1Li()r1 from the Il~
source is detected ancl ~)roceused to deterr(lLIle Llle dev:Lc/ti.orl bf tweerl ttle true
target position and t1-1e trainec's point of aim 3S ~I function c,f time. In the
M-70 Training Set lO, the signals generated are used to drLve a line-of-
sight indicator and the scoring mechanism in the instructor~s console 20.
lhe score obtained by a trainee gunner during a sirnulated
flight time can be tabulated to provide a permanent record of his accuracy
and progress. A score of lO0 would indicate perfect tracking. Typically,
a score of 90 will be obtained for a test of a predetermined time period if
the mean square tracking errors in both a~imuth and elevation are less than
.05 milliradians.
In accordance with the present invention, there is provided
an optical system 30 adapted to be removably secured to the sighting and
tracking unit 16 that forms part of the M-70 Training Set lO. This is best
shown in Figures l and 2. It should be noted here that the sighting and
tracking unit 16 includes a conventionall eyepiece and a fixed focal length
lens system providing 13 power magnification. The objective lens of this
lens system produces a real image at the reticle plane for distant objects.
That lens system is contained within a housing shown generally at 34. Such
a lens system allows a trainee gunner to focus on a target as close as 65
meters within the adjustability normally accommodated by the trainee's own
eye. However, at this range the sight will have some parallax due to dis-
placement of the real image from the reticle plane. In that instance, lateral
motion of the trainee's eye with respect to the eyepiece will cause apparent
motion of the target with respect to crosshairs provided in that optical
system. This parallax is unimportant in service, since a typical target at
65 meters will fill the entire field-of-view.
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In indoor adaptation o~ the M-70 Tralning Set 10, any ~uch internal
parallax in viewing the target is unacceptable. The scoring syst~m of the M-70
Training Set 10 demands very hlgh precLsion frr~n anyone operating the unit.
Accordingly, a correcting lens 36 is provLde(l ln frorlt of the objective lens of
the telescopic sight of sighting and tracking unit 16. This correcting lens 36
is removably mounted by fasteners 38 in a suitable opening provided in a front
plate 40 of a box frame 42. The box frame 42 is secured to a mounting plate or
base 44~ Clearly, the base 44 and any rear-plate that may be provided in the
box frame 42 will contain apertures in alignment with the correcting lens 36
and the objective lens of the telescopic sight of the Gighting and tracking
unit 16.
~lso in accordance with this invention, the box frame 42 is used to
support a beam-splitter 46. This beam-splitter 46 is of conventional design
being generally rectangular in shape and supported in a correspondingly shaped
opening in a diagonal plate 48. Opposite edges of the plate 48 are conveniently
spot welded to the side or end plates of the box frame 42. Beam-splitter 46
functions to direct a first portion of an incident beam transmitted through the
correcting lens 36 and to transmit a second portion to the telescopic sight.
The first portion of the incident beam is reilected from a reflecting surface 50
into a detector contained in housing 52 of the sighting and tracking unit 16.
This detector senses the presence of infrared radiation in the incident signal
reflected to it. In this instance, the IR source is a GaAs, continuous wave,
laser diode with a power output of between 5 and 10 milliwatts at .7 to 1.0 micro-
meters wavelength. One such laser diode that is commercially available is
Laser Diode Laboratory Inc. Model LCW lO.
The reflecting mirror 50 is adjustably and removably mounted on
a plate 54 that makes up one arm of a generally V-shaped bracket shown
overall at 56. This bracket 56 is secured by spot welding or the like to
the mounting plate 44. Suitable apertures are again provided in both the
mounting or base plate 44 and the other arrn of the bracket 56 to permit
the first portion of an incident beam to be reflected into the IR detector
within housing 520 The reflecting mirror 50 i9 adjustably positioned
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n a ~;u i L ~ cll~( r l~ rr~ t il~ ~,I (J ~ "~ r~ ;t~ J j t~ ir
PrO~/ jCIe(1 I,Y meCII19 Or V( rn j~r rII()nnI jn~!~ S~ r (WS 5~.
TO SUmrrlariZe t)rierly~ le ol)tlC;Jl adal)Ler 3() i8 de~;igtled
to be removab1y rnountable c,n t~lc sig~tillg al-l(J trackinK urlit 16 of an M-70
Trsining Set 10. rlhe cortecLirlg or collial.lL-irlg 1~ns 36 arld rnirrors 46 and
5() are mounted on accurflte1y al-lcllirled inlllrrlirmm l)1atts. ~lterllaLlvely~
another material such as stainless steel could be used, but at a weight
penalty, The mounting box 42 and V-shaped brackets 56 are attaclled to the raount-
ing plate 44. Attachment to unit 16 is by a "snap on" device similar to
that used with a M-70 Field TesL Set Collimator (not shown). Accordingly,
the optical adapter 30 is installed by pushing it in place and applying a
gentle pressure until locking occurs. Subsequently, only minimal optical
adjustments will be required to place the unit into operation. Reraoval
of the optical adapter 30 is virtually instantaneous, simply by giving it
a sharp pull away from the tracking unit 16.
In a preferred target simulation using the present invention,
a miniaturized replica of a battle tank, armour vehicle or other such target
is used. Such a miniaturiæed target is equiped with an infrared emitting
diode located at its center. This target is adapted to be driven by a
drive rnechanism along a curved track, and panorarnic scenery is mounted on a
supporting frame both behind and in the foreground of the movable target.
The miniature target is moved on the curved track at angular
speeds of from 5 to 25 milliradians per second, which simulates target
velocities of 5 to 25 mph at 450 meters range. Horizontal motion is either
clockwise or counter-clockwise, and remains without vibration over a distance
of 20 feet~ In this configuration, lirnited vertical rrlotion of the target-can
also be provided, but may be difficult to implement if the drive mechanism is
to remain hidden Erom the gunner trainee. The following descriptions relate
to the technical characteristics of two prototype M-70 indoor simulators of
which prototypes have been tested:
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Coll imating Lens
a. Focal Length 4 rneLers
b. ~ccuracy one~(ln~lrter wavelerlgt~
c. Type plano-corlvex, urlcollte(J
~eam-Splitter Mirrors
a. Form Rectangular, 3.5 X 5 in
b. Surface Accuracy one-4uarter wavelength
c. Type first surface
One of these mirrors has an elliptical hole, 1 in. by 1.41 in.
centered on the reflecting surface, and has its major axis parallel to the
5-inch dimension of the mirror. This hole i8 made by a one inch diaMeter
diamond drill with the mirror supported at 45 to the drill axis.
A two-axis adjustment of one of the beam-splitter mirror is
provided. The adjustments are located as to be readily accessible to an
instructor standing beside the weapon. The adjustment range does not exceed
~ 5 milliradians and the nominal centre position is indicated. The backlash
of the mechanism does not exceed .025 milliradians. The sensitivity is one
milliradian per turn of the adjustment knob.
~0 Adaptor Mounting Plate - A mounting plate similar to that used conventionally
with the collimator of the TCW Field Test Set.
Certain modifications and changes will become ~Ipparent. For
example, the collimating or correcting lens 36 of 4 meter focal length could
be changed, or replaced with a variable focus length collimating system
adjustable to provide a foca] length of from about 3 to about 10 meters.
Similarily, instead of a "push-pull" interconnection of the adapted unit 30
to the sighting and tracking unit 16, screw threaded fasteners could also
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be madt of a t;Lnr(ly polyrll(ri(: In;lL( rin:l ratiler tllan me~-fli ~ sub jecL orl~ LO
tlle desircll)ility Of m.3irltaillin~ c~ re(llJiretl dl~rer of accuracy to accomlrlo-
date 0l3tica] ].:ine~;-or-6i~llL, ar~ ellerfJI f;tlJrcllntf;t;. ()tl~er rr~odifications
will become a~l,arel" ~0 tl~ot:e skiL]e(J in tll:ifl llrt. 1l: is inLelldeci wit3~1irl
the scope of tl~i6 irlventiorl to erlcolnp~lt;~ /1l] ~ cll~lrl~es arlll modiflcf3ti(Jn
as would fall within tlle cla ims belo~,J.
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