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Modify solution heuristics. Do the cruise AoA and tail incidence only

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when the lift/drag are really solid.  And defer the approach trim until
the all four of the other variables are perfect.  I believe this should
fix the solution failures under gcc 2.95.2.
This commit is contained in:
andy 2002-05-29 08:41:13 +00:00
parent adeeed1a0e
commit 7e63c0f6e8
1 changed files with 33 additions and 21 deletions
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54
src/FDM/YASim/Airplane.cpp
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@ -8,6 +8,7 @@
#include "Thruster.hpp" #include "Thruster.hpp"
#include "Airplane.hpp" #include "Airplane.hpp"
namespace yasim { namespace yasim {
// gadgets // gadgets
@ -794,6 +795,16 @@ void Airplane::solve()
_solutionIterations = 0; _solutionIterations = 0;
_failureMsg = 0; _failureMsg = 0;
while(1) { while(1) {
#if 0
printf("%d %f %f %f %f %f\n", //DEBUG
_solutionIterations,
1000*_dragFactor,
_liftRatio,
_cruiseAoA,
_tailIncidence,
_approachElevator.val);
#endif
if(_solutionIterations++ > 10000) { if(_solutionIterations++ > 10000) {
_failureMsg = "Solution failed to converge after 10000 iterations"; _failureMsg = "Solution failed to converge after 10000 iterations";
return; return;
@ -816,7 +827,7 @@ void Airplane::solve()
runApproach(); runApproach();
_model.getBody()->getAngularAccel(tmp); _model.getBody()->getAngularAccel(tmp);
float apitch0 = tmp[1]; double apitch0 = tmp[1];
_model.getBody()->getAccel(tmp); _model.getBody()->getAccel(tmp);
float alift = _approachWeight * tmp[2]; float alift = _approachWeight * tmp[2];
@ -846,25 +857,20 @@ void Airplane::solve()
float tailDelta = -pitch0 * (ARCMIN/(pitch1-pitch0)); float tailDelta = -pitch0 * (ARCMIN/(pitch1-pitch0));
// Sanity: // Sanity:
if(dragFactor <= 0) { if(dragFactor <= 0 || liftFactor <= 0)
_failureMsg = "Zero or negative drag adjustment."; break;
return;
} else if(liftFactor <= 0) {
_failureMsg = "Zero or negative lift adjustment.";
return;
}
// And the elevator control in the approach. This works just // And the elevator control in the approach. This works just
// like the tail incidence computation (it's solving for the // like the tail incidence computation (it's solving for the
// same thing -- pitching moment -- by diddling a different // same thing -- pitching moment -- by diddling a different
// variable). // variable).
const float ELEVDIDDLE = 0.0001f; const float ELEVDIDDLE = 0.001f;
_approachElevator.val += ELEVDIDDLE; _approachElevator.val += ELEVDIDDLE;
runApproach(); runApproach();
_approachElevator.val -= ELEVDIDDLE; _approachElevator.val -= ELEVDIDDLE;
_model.getBody()->getAngularAccel(tmp); _model.getBody()->getAngularAccel(tmp);
float apitch1 = tmp[1]; double apitch1 = tmp[1];
float elevDelta = -apitch0 * (ELEVDIDDLE/(apitch1-apitch0)); float elevDelta = -apitch0 * (ELEVDIDDLE/(apitch1-apitch0));
// Now apply the values we just computed. Note that the // Now apply the values we just computed. Note that the
@ -875,8 +881,8 @@ void Airplane::solve()
applyLiftRatio(liftFactor); applyLiftRatio(liftFactor);
// DON'T do the following until the above are sane // DON'T do the following until the above are sane
if(normFactor(dragFactor) > 1.1 if(normFactor(dragFactor) > 1.0001
|| normFactor(liftFactor) > 1.1) || normFactor(liftFactor) > 1.0001)
{ {
continue; continue;
} }
@ -884,19 +890,25 @@ void Airplane::solve()
// OK, now we can adjust the minor variables: // OK, now we can adjust the minor variables:
_cruiseAoA += 0.5f*aoaDelta; _cruiseAoA += 0.5f*aoaDelta;
_tailIncidence += 0.5f*tailDelta; _tailIncidence += 0.5f*tailDelta;
_approachElevator.val += 0.5f*elevDelta;
_cruiseAoA = clamp(_cruiseAoA, -0.174f, 0.174f); _cruiseAoA = clamp(_cruiseAoA, -0.175f, 0.175f);
_tailIncidence = clamp(_tailIncidence, -0.174f, 0.174f); _tailIncidence = clamp(_tailIncidence, -0.175f, 0.175f);
_approachElevator.val = clamp(_approachElevator.val, -1.f, 1.f);
if(norm(dragFactor) < 1.00001 && if(norm(dragFactor) < 1.00001 &&
norm(liftFactor) < 1.00001 && norm(liftFactor) < 1.00001 &&
abs(aoaDelta) < .000017 && abs(aoaDelta) < .000017 &&
abs(tailDelta) < .000017 && abs(tailDelta) < .000017)
abs(elevDelta) < 0.00001)
{ {
break; // If this finaly value is OK, then we're all done
if(abs(elevDelta) < 0.0001)
break;
// Otherwise, adjust and do the next iteration
_approachElevator.val += 0.8 * elevDelta;
if(abs(_approachElevator.val) > 1) {
_failureMsg = "Insufficient elevator to trim for approach";
break;
}
} }
} }
@ -906,10 +918,10 @@ void Airplane::solve()
} else if(_liftRatio < 1e-04 || _liftRatio > 1e4) { } else if(_liftRatio < 1e-04 || _liftRatio > 1e4) {
_failureMsg = "Lift ratio beyond reasonable bounds."; _failureMsg = "Lift ratio beyond reasonable bounds.";
return; return;
} else if(Math::abs(_cruiseAoA) >= .174) { } else if(Math::abs(_cruiseAoA) >= .17453293) {
_failureMsg = "Cruise AoA > 10 degrees"; _failureMsg = "Cruise AoA > 10 degrees";
return; return;
} else if(Math::abs(_tailIncidence) >= .174) { } else if(Math::abs(_tailIncidence) >= .17453293) {
_failureMsg = "Tail incidence > 10 degrees"; _failureMsg = "Tail incidence > 10 degrees";
return; return;
} }