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| Line 13: |
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| Note that as the new 787 uses JSBSim, this tutorial will focus on implementing the FBW to an aircraft running with JSBSim. | | Note that as the new 787 uses JSBSim, this tutorial will focus on implementing the FBW to an aircraft running with JSBSim. |
| | |
| | == B787-8 Fly-By-Wire == |
| | |
| | Another feature in the Boeing 787-8's Fly By Wire is the automatic control of the trailing edge camber which affects lift and drag. The fly-by-wire automatically adjusts that to get maximum efficiency. Redneck and I am working on that but it's not included in the below nasal code as I don't think any other aircraft has that. And ofcourse, it's not yet completed. The rest of the Fly-By-Wire is stable at the moment and has been tested on the new Boeing 787-8. |
|
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|
| == Functions == | | == Functions == |
| Line 232: |
Line 236: |
| throttle0 -= 0.001 * fpsfix; | | throttle0 -= 0.001 * fpsfix; |
| throttle1 -= 0.001 * fpsfix; | | throttle1 -= 0.001 * fpsfix; |
| }
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|
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| }
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|
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| if ((roll > -5) and (roll <= 5) and (me.turnthrottlefix == 1)) {
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|
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| if (throttle0 <= me.throttleinit - 0.05) {
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| throttle0 += 0.001 * fpsfix;
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| throttle1 += 0.001 * fpsfix;
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| } elsif (throttle0 > me.throttleinit + 0.05) {
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| throttle0 -= 0.001 * fpsfix;
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| throttle1 -= 0.001 * fpsfix;
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| } else me.turnthrottlefix = 0;
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| }
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|
| |
| ### Reduce throttle if aircraft is faster than 250 KIAS under 10000 ft
| |
|
| |
| if ((airspeedkt >= 250) and (altitudemsl <= 10000) and (throttle0 != 0) and (throttle1 != 0)) {
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| throttle0 -= 0.001 * fpsfix;
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| throttle1 -= 0.001 * fpsfix;
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| me.throttlefix = 1;
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| }
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|
| |
| if ((me.throttlefix == 1) and (airspeedkt < 245) and (altitudemsl <= 10000) and (throttle0 != 1) and (throttle1 != 1)) {
| |
| throttle0 += 0.001 * fpsfix;
| |
| throttle1 += 0.001 * fpsfix;
| |
| }
| |
|
| |
| ### Adjust Throttle to stay under Vne
| |
|
| |
| if ((airspeedkt >= 350) and (altitudemsl > 10000) and (throttle0 != 0) and (throttle1 != 0)) {
| |
| throttle0 -= 0.001 * fpsfix;
| |
| throttle1 -= 0.001 * fpsfix;
| |
| me.throttlefix = 1;
| |
| }
| |
|
| |
| if ((me.throttlefix == 1) and (airspeedkt < 340) and (altitudemsl > 10000) and (throttle0 != 1) and (throttle1 != 1)) {
| |
| throttle0 += 0.001 * fpsfix;
| |
| throttle1 += 0.001 * fpsfix;
| |
| }
| |
|
| |
| ### Adjust Throttle to keep from stalling
| |
|
| |
| if ((airspeedkt < 125) and (altitudeagl > 250) and (throttle0 != 1) and (throttle1 != 1)) {
| |
| throttle0 += 0.001 * fpsfix;
| |
| throttle1 += 0.001 * fpsfix;
| |
|
| |
| ### Also help by pushing forward on the stick
| |
|
| |
| elevatorout += 0.02;
| |
|
| |
| }
| |
|
| |
| ## RUDDER CONTROLS
| |
|
| |
| if (getprop("/controls/fbw/rudder")) {
| |
|
| |
| if ((roll < -5) or (roll > 5)) {
| |
| me.targetrudder = aileronout / 2;
| |
|
| |
| if (me.targetrudder < rudderout) rudderout -= 0.015;
| |
| if (me.targetrudder > rudderout) rudderout += 0.015;
| |
|
| |
| } }
| |
|
| |
| ## YAW DAMPER
| |
|
| |
| if (getprop("/controls/fbw/yaw-damper")) {
| |
|
| |
| if (rudderin > rudderout) rudderout += 0.05 * fpsfix;
| |
|
| |
| if (rudderin < rudderout) rudderout -= 0.05 * fpsfix;
| |
|
| |
| } else {
| |
|
| |
| rudderout = rudderin;
| |
|
| |
| }
| |
|
| |
| # Transmit output signals to surfaces
| |
|
| |
| setprop(fcs~"aileron-fbw-output", aileronout);
| |
| setprop(fcs~"elevator-fbw-output", elevatorout);
| |
| setprop(fcs~"rudder-fbw-output", rudderout);
| |
|
| |
| setprop("controls/engines/engine[0]/throttle", throttle0);
| |
| setprop("controls/engines/engine[1]/throttle", throttle1);
| |
|
| |
| me.throttle = throttle0; # This is to find out if the pilot moved the throttle
| |
|
| |
| } else {
| |
|
| |
| # Transmit input signals directly to surfaces
| |
|
| |
| setprop(fcs~"aileron-fbw-output", aileronin);
| |
| setprop(fcs~"elevator-fbw-output", elevatorin);
| |
| setprop(fcs~"rudder-fbw-output", rudderin);
| |
|
| |
| } | | } |
|
| |
| },
| |
| reset : func {
| |
| me.loopid += 1;
| |
| me._loop_(me.loopid);
| |
| },
| |
| _loop_ : func(id) {
| |
| id == me.loopid or return;
| |
| me.update();
| |
| settimer(func { me._loop_(id); }, me.UPDATE_INTERVAL);
| |
| }
| |
|
| |
| };
| |
|
| |
| fbw.init();
| |
| print("Fly-By-Wire ......... Initialized");
| |
|
| |
| # *Power-by-wire : corresponds to power steering in cars
| |
| </syntaxhighlight>
| |
|
| |
| === -set.xml ===
| |
|
| |
| Call the Nasal file in your aircraft's -set.xml file by adding the following code inside <nasal></nasal>
| |
|
| |
| <syntaxhighlight lang="xml">
| |
| <fbw>
| |
| <file>Aircraft/787-8/Nasal/fbw.nas</file>
| |
| </fbw>
| |
| </syntaxhighlight>
| |
|
| |
| Replace '787-8' with your aircraft folder name.
| |
|
| |
| === JSBSim FDM ===
| |
|
| |
| Replace 'aileron-cmd-norm' with 'aileron-fbw-output', replace 'elevator-cmd-norm' with 'elevator-fbw-output' and finally, replace 'rudder-cmd-norm' with 'rudder-fbw-output'.
| |
|
| |
| For example,
| |
|
| |
| <syntaxhighlight lang="xml">
| |
| <summer name="Pitch Trim Sum">
| |
| <input>fcs/elevator-cmd-norm</input>
| |
| <input>fcs/pitch-trim-cmd-norm</input>
| |
| <clipto>
| |
| <min> -1 </min>
| |
| <max> 1 </max>
| |
| </clipto>
| |
| </summer>
| |
| </syntaxhighlight>
| |
|
| |
| was changed to
| |
|
| |
| <syntaxhighlight lang="xml">
| |
| <summer name="Pitch Trim Sum">
| |
| <input>fcs/elevator-fbw-output</input>
| |
| <input>fcs/pitch-trim-cmd-norm</input>
| |
| <clipto>
| |
| <min> -1 </min>
| |
| <max> 1 </max>
| |
| </clipto>
| |
| </summer>
| |
| </syntaxhighlight>
| |
|
| |
| == Configuration ==
| |
|
| |
| Add the following switches anywhere (preferably the CDU) to be able to configure the CDU in FlightGear:
| |
| * /controls/fbw/active (controls whether the fly-by-wire system is active or not)
| |
| * /controls/fbw/yaw-damper (controls the yaw damper)
| |
| * /controls/fbw/rudder (controls whether the fly-by-wire controls rudder or not)
| |
| * /controls/fbw/bank-limit (controls the aircraft's bank limit)
| |
|
| |
| If you don't want any of the configurations to be edited in Flightgear, but configured generally, add the following under </sim> to your -set.xml for the appropriate properties you want to configure:
| |
|
| |
| <syntaxhighlight lang="xml">
| |
| <controls>
| |
| <fbw>
| |
| <yaw-damper type="int">1</yawdamper>
| |
| <rudder type="int">1</rudder>
| |
| <bank-limit type="int">30</bank-limit> <!-- 30 degrees bank permitted -->
| |
| </fbw>
| |
| </controls>
| |
| </syntaxhighlight>
| |
|
| |
|
| |
| [[Category:Howto]]
| |
| [[Category:Nasal]]
| |