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TECS: remove logic which shifts or limits integrator during large transients 

- during large transients in pitch demand the pitch integrator value
was shifted such that the final demanded pitch did not violate given
limits. Since this strategy can cause large knock-backs of the pitch
integrator we remove this logic completely. We already have logic in place
which reduces the integrator at the pitch time constant in case the
pitch limits are exceeded so we don't need to limit it further. This
has the advantage that spikes in the specific energy balance error
signal does not lead to integrator knock-back.

Signed-off-by: Roman <bapstroman@gmail.com>
This commit is contained in:
Roman 2016-11-03 09:55:18 +01:00 committed by Paul Riseborough
parent 9221c74e46
commit 896118281c
1 changed files with 0 additions and 14 deletions
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14
src/lib/external_lgpl/tecs/tecs.cpp
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@ -475,20 +475,6 @@ void TECS::_update_pitch(void)
SEB_correction += _PITCHminf * gainInv;
}
// Apply max and min values for integrator state that will allow for no more than
// 10deg of saturation. This allows for some pitch variation due to gusts before the
// integrator is clipped. Otherwise the effectiveness of the integrator will be reduced in turbulence
float integ7_err_min = (gainInv * (_PITCHminf - math::radians(10.0f))) - SEB_correction;
float integ7_err_max = (gainInv * (_PITCHmaxf + math::radians(10.0f))) - SEB_correction;
_integ7_state = constrain(_integ7_state, integ7_err_min, integ7_err_max);
// if the specific engergy balance correction term produces a demanded pitch value which exceeds the aircraft pitch limits
// then zero the integrator. Not doing so can lead to the integrator value being shifted to large unwanted values due to the
// constraint right above this comment
if (SEB_correction / gainInv > (_PITCHmaxf + math::radians(10.0f)) || SEB_correction / gainInv < (_PITCHminf - math::radians(10.0f))) {
_integ7_state = 0.0f;
}
// Calculate pitch demand from specific energy balance signals
_pitch_dem_unc = (SEB_correction + _integ7_state) / gainInv;