From 7e39fd5d597c3052d4751900c776bc6fad373ecd Mon Sep 17 00:00:00 2001 From: Mikhail Grushinskiy Date: Tue, 14 May 2024 13:57:54 -0400 Subject: [PATCH] upd --- docs/bareboat-math.adoc | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/docs/bareboat-math.adoc b/docs/bareboat-math.adoc index 73ce958b..2eaee19b 100644 --- a/docs/bareboat-math.adoc +++ b/docs/bareboat-math.adoc @@ -414,6 +414,25 @@ sos = signal.butter(2, freq_in_hertz * 8, 'low', fs=SAMPLE_RATE, output='sos') low_pass_filtered = signal.sosfilt(sos, accZ_val) ---- +=== Aranovskiy on-line frequency estimator + +Instead of FFT method for finding main wave frequency we could use Aranovskiy frequency estimator which is +a simple on-line filter. + +Ref: + +Alexey A. Bobtsov, Nikolay A. Nikolaev, Olga V. Slita, Alexander S. Borgul, Stanislav V. Aranovskiy + +The New Algorithm of Sinusoidal Signal Frequency Estimation. + +11th IFAC International Workshop on +Adaptation and Learning in Control and Signal Processing +July 3-5, 2013. Caen, France + +https://www.sciencedirect.com/science/article/pii/S1474667016329421[The New Algorithm of Sinusoidal Signal Frequency Estimation] + + + == Measuring wave height from a moving boat @@ -522,6 +541,9 @@ Vertical velocity and heel are correlated. It would be interesting to study thei . Sharkh S. M., Hendijanizadeh2 M., Moshrefi-Torbati3 M., Abusara M. A.: A Novel Kalman Filter Based Technique for Calculating the Time History of Vertical Displacement of a Boat from Measured Acceleration, https://www.researchgate.net/profile/Mehdi-Hendijanizadeh/publication/264713649_A_Novel_Kalman_Filter_Based_Technique_for_Calculating_the_Time_History_of_Vertical_Displacement_of_a_Boat_from_Measured_Acceleration/links/53ec88db0cf24f241f1584c5/A-Novel-Kalman-Filter-Based-Technique-for-Calculating-the-Time-History-of-Vertical-Displacement-of-a-Boat-from-Measured-Acceleration.pdf[Marine Engineering Frontiers (MEF) Volume 2, 2014] . https://en.wikipedia.org/wiki/Trochoidal_wave[Trochoidal Wave Wikipedia] +. Alexey A. Bobtsov, Nikolay A. Nikolaev, Olga V. Slita, Alexander S. Borgul, Stanislav V. Aranovskiy: The New Algorithm of Sinusoidal Signal Frequency Estimation. 11th IFAC International Workshop on +Adaptation and Learning in Control and Signal Processing +July 3-5, 2013. Caen, France: https://www.sciencedirect.com/science/article/pii/S1474667016329421[The New Algorithm of Sinusoidal Signal Frequency Estimation] . https://en.wikipedia.org/wiki/Wind_wave[Wind Wave Wikipedia] . https://wikiwaves.org/[Wiki Waves] . https://github.com/seandepagnier/RTIMULib2[RTIMULib2 IMU library]