Martin-Marietta Aerospace Simulation & Test Laboratory
I
.
Martin- Harietta Aerospace Simulation & Test Laboratory
General
In Martin-Marietta ' s Simulation & Test Laboratory (STL) , a wide variety
of missile guidance and aircraft fi re control systems are simulated, tested
and evaluated . The STL consists of the following areas: 1) Han-in-the-Loop
Simula tion System. 2) Rada r Guidance Simulation System , 3) Heliport Flight
Opera ti ons , 4) Outdoor Lab & Range Operations. and 5) Radar Antenna Test
Chambe rs. The STL is a separate comple~ and is shown in Figure 1 . Only
t he Man-in-the-Loop Simul ation System
(~ULS)
will be described and consists
of the simulation of: 1) the Advanced Attack Helicopter (AAR), 2) the A- lO
aircrafe. and 3) the F- 16 aircraft. Basically, thr ee different cockpits
are used in conjunction with other common simulation elements. The purpose
of the simulation system is to provide the same complex interaction as
the aircraft between the crew. the aircraft and the avionics systems . Large
dynamic. closed - loop. real- time . 6 degree-of-freedom systems are used which
enab le ~rnA to demonstrate the feasibility of the pilot or crew to efficiently
and effectively perform target acquisition and air-to-surface weapon delivery
us ing stabilized sensors with automatic tracking capability. various controls
and displays, cueing informati.on 'and assorted weapons. This is accomp lished
by experimental stud i es of equipment utilization, operating techniques. co ntrol
fl ' rlctions and display symbology tha t can be performed during simula ted mission
flights against t ypical targets on a three-dimensional terrain model .
Th e s imulation enables the pilot Dr crew seated in a cockpit to fly
missions over a 80 ' by 40' terrain mod el usi ng visual cockp it displays whose
scenes are provided by sensors on the simulated aircraft. Figure 2 shows the
simulation element s . The aircraft flight over the t e rrain model (furopean
environment) is simulated by a 6 degree-of - freedom motion system that in cl udes
th e terrain model. A large gantry containing two (2) television systems is
suspended over the terrain mod el. The windscreen probe and TV r epresents the
aircraft and can reproduce aircraft rotations, an gular velo cities and angular
accelerations fo r three degrees of angu l ar f r eedom . The sensor probe and TV
r ep r esents the fire contro l system and provides a magnified sma ll field - of-view
scene.
The three degrees of translational freedom are obtained by moving the
terrain model along a stra igh t line horizontal path and by moving the probes
and television systems both in a vertical direction and in a horizontal
direction . The translations, velocities and acc el erations are scaled acco rding
to the terrain model scale whi c h is scaled at 225 :1 for helicopter operations
and 1200:1 for fixed-wing aircraft operation .
The simulation is controlled by a hybrid computer arrangeme nt composed
of three (3) Sigma 5 digital compute rs, six (6) EAI 231-RV analog computers
and appropriate ins trumentation, interface and peripheral equipment. A typical
mission would have the aircraft as represented by the windscreen probe and
TV located at some i.nitial position with respect to a target area on the
terrain model . The mission would be started and the pilo t would fly the aircraft
against the target (tanks , trucks, br idges, et c . ) using the cockpit visual and
instrument displays. As the flight progresses, the compu ters are used to
co n trol the aerodynamics and to process commands to the sensor probe and TV
-2and to determine where it is looking, to handle operational mod e logic and
switching fun ctions , to perform weapon delivery calcula tions, and to generate
commands to position symbology on the visual displays.
The mission is terminated
when a weapon is released and breakaway is completed.
The cockpits can be located either on the 6 degree-of-freedom motion base or
operated from 2 separate rooms which contain identical interface consoles. The
MTLS system is designed for less than 1 hour changeover from one aircra ft system
to another..
The follow ing paragraphs describe tbe simulation elements.
Terrain Hod el
The terrain model (Figures 3 and 4) is 80 ' by 40 ' with a fiber glass
surface which can be walked on for target changes. Three foot mirrors ring
the terrain model for te rrai n extensiorL. The terrain model has scales oE 1200 : 1
and 225 : 1 . Simula tion parameters for 1200 : 1 are :
Slant range
Altitude
Lateral range
Long j tudinal velocity
Vertical veloci t y
La teral velocity
100,000 ft.
12 , 000 ft . (max) 8, Et. (min)
to
to
to
to
48 , 000 ft.
12 , 000 ft/s
7 , 200 Etls
4 , BOO ftls
The terrain model consists of mountains , plains , harbors , streams , ridges ,
forests, dams , tunnels, highways. railroads , bridges , airports, bu ildings,
doc ks, etc. Topography is rol l ing hills modeled after West Germany . Choic e
of materials used in the manufacture of the ter.rain model was based on weather
aod 5un resistance and , at the same time, a presentation of realistic targets
to the sensors .
LightinS
The environments c ontrolled in the terrain model r oom are lighting and
temperature . The lighting is a combination of low ripple (1 percent maximum),
fluorescent , and metal halide lighting. The low ripple system is provided
by 750 watt incandescent lamps giving approximately 200 footca ndles 36 inches
above the floor. Tbe fluorescent system provides 500 footca nd les and may
be reduced by increments of 50 footcandles. The metal halide system provid es
2000 footcandles. Condit ione.d air is provided to maintain a temperature of
75°F + 5°.
Longitudinal Transport Mechanism
The 3- D terrain model is mounted on 30 trucks , and 10 central trucks with
compound bearings prov id e lateral guidance in addition to vertical guida nce .
The trucks allow trans l ation of the assembl y in a longi t udinal direction on
three tracks . The characterist i cs of the terrain model longitudinal drive
assembly are l isted below :
I
-)-
+80 feet
Displacement
Acceleration
Ac c uracy at min +1.0 per cent at 0 . 01 It/s
Accuracy at max + . 05 percent at 10 ftls
2
:!:.lO . O ft/sec
Positioning
Accuracy ~.l in ch
Velocity
Repeatability .02 inch max.
Small signal frequency
response
Weight of lungit udina l
drive system
3 . 0 cps
24.000 Ihs. static and rolling f ri ction
l ess than 250 Ibs.
The 3-D terrain model is mechanized t o simulate the longitudinal movement
of the air craft in flight ; and, t herefore , ac co unts fo r one degree of freedom .
Vertical and Lateral Trans port Mechanisms
The remaining two degrees of translational freedom to simulate ve r tica l
and lateral movement of the aircraft are provided by a lateral carriage and a
horizontal beam. The latera l carriage is free to translate laterally and is
attached to a horizontal beam which is free to move in the vert i ca l dir ection
between t ..... o supporting columns . The operating characteristics of the lateral
and vertical drive systems are :
Displacement
Lateral and Vert i cal Drive Characteristics
Ve rtical
Lateral
25 Et 7 in
38 ft
Velocity
Accurac y a t minimum
Accuracy at maximum
Accelerations
+1. 0 percent at 0 . 004
±,l.O percent at 0.006 ftls
. 05 percent at 4 . 0 Et/s . 05 percent at 6.0 itls
2
2
4 Et/s
6.0 ftls
Positioning
Accura cy
Repeatability
+ .02 inch
-.-005 in max
+.02 in ch
.005 in max
Small Signal f requency
response
3 . 0 cps
3.0 cps
Winds creen Probe
Thi s i s 8n opti cal probe (Figure 5) to provide the pi l ot with an
out-the- ..... lndow presentation . It is a Schelmpflug cor rect ed pr obe wh i ch has
essentially an infinit e depth of field. I t also will alLow low I.eve l «100 ft)
operation over the ter rain model . The specifications are:
1.
Fields of View
50" circular
33 . 3" circ ular
12.5 " ci r cular
-1
"
-42.
Minimum altitude
10 mm
"-
40 feet (1200,1)
3.
Nea r focus
25 mat
"-
laO feet (1200, 1)
4.
Resolution
2.3 arc min at 25% HTF
5.
Servo Performance
Roll
Displacement
Continuous
Velocity
Pit ch
+ 25° . -90"
Yaw
Continuous
lOaD/sec
360 o /sec
360 o /sec
This probe and the sensor probe are mounted on the lateral carr iage above the
terrain mod el.
Sensor Probe
The sensor probe (Figure 5) is used to simu l ate a fire control system.
It is a Scheimpflug correc ted probe which has essentially an infinite dep'th
of field a llowing low level «100 ft) operation over the terrain model .
speci f i c ations are:
1.
Field of View
01 Snout
112 Snout
6° circular
20 0 c ircular
4° circular
1] . 3° circular
1. 5° circular
5° ci rcular
84 ft (1200:1)
20 mm
1200 ft (1200:1)
300 mm
2.
Minimum Altitude:
20 mm
3.
Near focus:
300 rom ~
4.
Resolution
17 arc seconds at
~
25% MTF
5.
The
50 arc seconds at
25. HTF
Servo Performance
Displacement
Velocity
Roll
Continuous
360 0 /sec
Pitch
+25 °, _90 0
IOOo /sec
Yaw
Continuous
360 o /sec
When the windscreen and sensor probes ar e mounted on the lateral carriage,
the longitudinal separation between entrance pupils of the two probes w111 be
12 inches.
High Resolution TV
Two 1200 line, 60 MHz high resolution TV systems (Figure 5) are used
with these probes. Both systems have a variable line rate and bandwidth
so that they can be used to simulate a ~ystem with aoy resolution up to
-51200 lines with a li nearity of less thon 0.1%.
A set of dis tri bution
amplifiers is included in the TV cont rol console, and distribution
amplifiers are included in" each cockp i t interface co nsol e . These distribution
amplifiers are all differential to minimize 60 Hz interference.
can be used with Martin Marietta TV trackers .
These systems
When used with the optical
pro bes , these TV systems yield resolutions of 4.4 arc minutes for the windscreen probe at 50° field of view, and 17 arc seconds for the sensor pr obe
at 1.5 degree field of view.
The TV systems can also be electronically zoomed
at a r atio of 4:1 i n conjunction with the probes to provide a variety of f ields
of v i ew.
Visual Display Systems_
Two black and white. high resolution, high accuracy , infinity focus
visual display systems provide a 50 0 field of view of the terrain model to the
pilot through the windscreen of the co ckpit . The op tics for ea c h system cons ist
of lt large diameter (up to ltO") plastic refractive len ses . The scene is provided
by a 25 " Cathode Ray tu be which can provide up to 1200 lin es with linearity and
geometric accuracy of less than 1% of picture height. The overall resolution
is 4 Arc Minute S/Line Pair and a brightness of up to 25 footlamberts.
Spec i al Effects Generator
A special effec t s gene rat or provides low c eiling and limited visibility
e f fects and provides a horizon and sky.
Computer Laboratory
The computers pr ovide the means of ca lculat ing the equat ions of the
mathematical imp l ementation of missi le or aircraft aerodynamic. kinematics.
and autopilot. The computer laboratory (Figure 6) is the central control room
where all data is normally gathered . The computers contain the computational
elements li sted be low:
GDC Hybrid Computer Complement
Digital Comput er
S igma 5 - Tripl e CPU
t-l emory size
Word length
Memor y c ycl e time
Arithmetic
160K words
32 bits
1. 0).Js
Fixed point and floating
point.
Analog Comput ers
231R-V's
Number of consoles
Total number of amplifiers
Quarter-square multipliers
Resolvers
Potentiometers - Servo Set
Potentiometers - Hand Set
Function generato rs
6
1496
276
30
900
140
120
-6Hybrid Interface
(digital computer/231R- V)
Multiplying Digital to
analog converters
Analog to digital
converter c hannels
56
48
Pe ripheral devices - Sigma 5
2 card readers
4 mag tapes
2 line printers
2 (heed head disk memories
1 disk pack
& 1500 car/min
75 inches per sec
800 bits/in~ h
800 & 1000 lines/min
132 char/line
6. 0 Mbyt~s
400
48 Mbytes
Control Conso l es
Control consoles are used for translational and rotational drive co ntrol
as well 3S lighting and closed c ir cui t TV cont rol.
In general , the consoles
provide mode of operation (veloci ty or position and manual or computer cont rol).
manage the general signa l routing. and provide the outlets for availability of
sel ected parameters to be measu r ed . The cont rol console has provisions for
manually inlroducing a position or rate command for each of the six degrees of
f r eedom , independently or simultaneously.
Crew Station Labo ratory
The motiol] base building houses a 6 OOF motion base (Figure
for 2 fixed base operational cockpits .
specifieations.
Pay load
Ven:ica 1 travel
Lateral travel
Longitudinal travel
Roll travel
Pit ch travel
Yaw travel
7) and space
The motion base has the following
18,000 lbs .
+33. -38 inches
+58 inches
+53 inches
±.J2 degrees
+36 , - 31 degrees
+32 degrees
AAH Cockpit
A tandem helicopter cockpit (Figure 7) has been configured as a YAH-64
Advan ced Attack Helicopte r. The cockpit consists of two sec tions, the rear
be ing the pilot's posi tion and the forward configured for the co- pilotl
gunner position. The interior of both cockpi.t sect.ions represent.s the proposed
layout o f the production version of the YAH-64 as of July 77.
The pilot ' s section is configured wit.h a fu ll complement of operational
flight and engine instruments (engine instruments to be installed by Feb. 78).
The primary f"ire co ntrol and visionics panels are operational with the balance
of the panels c.onfigured as phnto mockups .
-7The pilot's flight controls consist of cyclic, pedals , and collective
assembly. The artificial feel system is programmable and has the capability
to simulate any helicopter control system . The pilot ' s grip is identical to
that for the YAH-64.
The cockpit interior is painted black , for compatibility with night vision
goggles .
The interior lighting is red and all instruments and panels are integ-
rally lighted and dimmable.
In addition, complete provisions have been made for
installation of a Helmet Display and Sight System.
The co- pilot/gunner section is configured with a fully operational (simulated)
Target Acquisition and Designation System (TAOS) . In addition, the primary fire
contro l and visionics panels are operational wi t h the remainder of the panels
and instruments configured as photo mockups .
An aural simu.latiOll is also prOVided for the MH.
It simulates rotor and
tail rotor sounds. tu_rbine whine, weapon firing , and wind cues. The system is
programmable and is driven by the aero-model software .
A-IO Cockpit
An A-IO coc kpit (Figure 8) is available which can be installed on the
motion ba se . This cockpit is a representation of A-lO aircraft number 11
(Tail No . 7500262) with all trainer applicable ECP ' s uo to May 9 . 1977 incorpot:ated.
The approximate size of this cockpit is 11 feet long, 6 feet high and 5 feet wide.
The cockpit int e ri.or represents the basic design of the A-IDA aircraft. All
instruments, indicators. gages , controls are located in the same position as
in the A-IDA .
A 20° FOV Helmet Mounted Display system and an A-lO Airborne Head - Up Display
are installed in the cockpi t. The A-IO cockpit has the same type of artific i al
control feel and aural simulation as the AAH . One of the visual display systems
will be mounted on the A-IO cockpit.
F-16 Cockpit
A 2-seat F-16 cockpit is available and is scheduled to be modified to
be installed on the motion base. Adequate instruments , displays and controls
are provided for air-to- ground weapon delivery missions. An airborne F-16
Head-Up Display is installed for symbology cues . The F-16 uses the same
aural simulation equ~pment as the A-IO cockpit with differences in drive
signals . A visual display system will be mounted on the F-16 cockpit.
The F-16 cockpit is shown in Figure 9 .
Figure 1.
Simulation and Test Laboratory
'B/W VISUAL
AAH,A-IO , FI6
'DISPLAYS
,&IMUl."TIO~
CONrROl CO~50lf
EADUP
DISPLAY
TARGET IMAGE
G'Et-IERA10R
COCKPllS F-16 -AID
AAH
TERRAIN MODEL SCALE 1200! flXED·W1WG
225 1 "RorAR""' WING
Figure 2.
Simulation Elements
Figure 3.
80 x 40 ft Terrain Model
Figure 4.
Terrain Model Closeup
Figure 5 .
Optical Probes and Televisions
•
• •
--
~
Figure 6.
Computer Complex
-
Figure 7 .
6 OOF Motion Base and Cockpit
,."
Figure 8 .
A-lO Cockpi t