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Code Issues Releases Activity

OP-1317 Changed filtering method of IMU airspeed calculation into a Butterworth second order filter

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Andres 2014-05-21 19:32:02 +02:00
parent 41dd85b741
commit 423645392b
1 changed files with 0 additions and 8 deletions
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8
flight/modules/Airspeed/imu_airspeed.c
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@ -169,14 +169,6 @@ void imu_airspeedInitialize()
*
* See OP-1317 imu_wind_estimation.pdf for details on the adaptation
* Need a low pass filter to filter out spikes in non coordinated maneuvers
* Note: filtering of xB and gpsV is more effective than of the airspeed itself. Reason: derivative of oscillating part is scaled
* by 1/period, i.e. fast oscillation => small period => large oscillation in derivative => large oscillation in airspeed
* Idea: treat gpsV and xB as noisy time series with trend and
* apply Holt-Winters double exponential smoothing to avoid smoothing out of trend (=derivative)
* s1 = x1
* b1 = x1 - x0
* s_{k+1} = alpha*x_{k+1} + (1-alpha)*(s_k + b_k)
* b_{k+1} = beta*(s_{k+1} - s_k) + (1-beta)b_k
*/
void imu_airspeedGet(AirspeedSensorData *airspeedData, AirspeedSettingsData *airspeedSettings)
{