Cessna172 :
# thrust weight max_rpm climb takeoff land stall
# dist dist
info 150 2300 2700 645 865 520 41
# mode speed power turn flaps gear attitude
cruise 109 75 std 0 up 0
<10K 109 75 std 0 up 0
C&D 109 75 std 0 up 0
downwnd 85 50 std 0 up 0
apch 80 30 30deg 20 down 0
final 65 20 30deg 30 down 0
climb 80 100 30deg 0 up 0
takeoff 55 100 30deg 0 down 5
tchdown 51 20 30deg 0 down 7
accel 0 100 30deg 0 down 0
brake 0 20 30deg 0 down 0
The tables are combined to fill missing values and minor computations are done.
Result of running the PERL script is the file aimodel.dat.
There is no 1:1 relation between the tabulation inside the PERL script and the final data in aimodel.dat.
The stall value is not stored, but just used to compute the attitude.
If you define more than 28 plane types you will not get more than 28 plane type entries in aimodel.dat.
Best way to modify AI parameters is to work directly using aimodel.dat. This file contains binary packet data and is not suitable for a texteditor. Working with hex data is very tricky but using AIModelViewer is
simple and quick.
You can download AIModelViewer v3.0 288KB right here.
You are using this freeware tool at your own responsibility !
Backup your aimodel.dat file before using this tool !
All load and save operations are using a file dialog box. You can work outside of the fu3 area also.
First select the aimodel.dat to open, then you can view all values of the 28 plane types as treeview.
There are 2 main sections for each plane type:
1. the info line
2. the mode matrix.
For each plane, the following information is tabulated in the info line:
1. max thrust, given in pounds.
2. gross weight (lbs)
3. the engine rpms at full power
4. the engine rpms at min. power = 0.2 * (rpms at full power)
5. the max climb rate, in feet per minute
6. the distance the plane takes to takeoff, (the time it's moving on the ground)
7. the distance the plane takes to land
caution the tabulated value for stall is not retained in aimodel.dat !
In addition, each of the following is tabulated for each plane type and each "mode":
1. speed (knots)
2. power, as a percentage of max power
3. turn type
0 halfstd for half-standard-rate turns
1 std for standard-rate turns, 360 degrees in 2 minutes
2 30deg for turns with 30 degrees of bank
3 ground for ground-reference turns
4. flaps (0, 10, 20, 30)
5. gear status (up=0 or down=1)
6. attitude computed by the PERL script from -31 to +31
if not entered in the PERL tabulation the script will compute attitude as
attitude = 15 * (stall / speed)^2 * ( 1.5 / (1 + 0.5*flaps/30.0)) - flaps/10.0 - correction;
rather wired, so better select a value inside the range to make a good looking plane.
See the possible range for the attitude here applied to the Cessna 172 in the Final mode with the values +31 and -31.
In both cases the transition to touchdown was smooth with a perfect landing - try it !.
the following modes are used:
1. cruise:
used for level flight over long distances.
For the airliners, this will be flight in the stratosphere
at speeds near that of sound.
2. cruise below 10000ft:
like cruise, except below 10,000 feet above sea level.
for the jets, this is much slower than cruise.
For other planes, it's identical or nearly so.
3. C&D:
used for flight in class C and D airspaces (also for B).
the speed limit here is even slower.
4. ground;
used for ground-reference turns near or in the pattern
5. downwind:
used for the downwind leg.
like C&D, except that the gear should be down.
6. approach:
used for the base leg, and for the end of the downwind leg.
7. final:
used for the final leg.
8. climb:
9. takeoff:
where the plane is when its wheels begin to leave the ground
10. touchdown:
where the plane is when its wheels touch the ground on landing
11. accelerate:
12. brake:
|
Address |
The Structure of the aimodel.dat file |
| 0x0000 |
Info part: 28 blocks of 28 bytes as 7 integer values (784 bytes total)
part(0) thrust
part(1) weight
part(2) max_rpm
part(3) max_rpm * 0.2
part(4) climb
part(5) takeoff distance
part(6) landing distance
|
|
0x0310 |
The second part contains the mode tabulation in compressed form
as 12 integer at 4 bytes = 48 bytes total for each plane entry.
One mode line is stored in 4 bytes ( X for used bits for the value )
speed 0000 0000 0000 0000 0000 00XX XXXX XXXX
power 0000 0000 0000 000X XXXX XX00 0000 0000
turn 0000 0000 0000 0XX0 0000 0000 0000 0000
flaps 0000 000X XXXX X000 0000 0000 0000 0000
gear 0000 00X0 0000 0000 0000 0000 0000 0000
attitude sXXX XX00 0000 0000 0000 0000 0000 0000
s = sign bit for attitude
The second part has a total of 28 * 48 = 1344 bytes
|
Information: André Meystre
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