Matrix

Table of contents

1. Dynamic Filter on Gyro
   1. Tuning
   2. Many options (0.3.X+)
   3. Variables and Values
2. Dynamic Filter on D-Term
   1. “Q” Example Graphic
   2. Dynamic Filter was formerly “Matrix”

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Dynamic Filter on Gyro

• The gyro Dynamic_Filter in EmuFlight 0.3.X (a.k.a. Matrix) is a per-axis dynamic gyro notch written by Paweł Spychalski.
• 0.4.0+ upgrades the dynamic_filter in part with code from KarateBrot and calculations from QuickFlash

Tuning

• EmuFlight stock defaults are fair for a 5” standard-frame quadcopter, but generally over-filter.
• Defaults have dynamic_filter enabled as well as 2 dTerm LPF’s, which again may be overfiltering. (Helio is disabled by default.)
• The goal of filter tuning is to have a quad-specific tune that is neither over-filtered nor under-filtered.

Many options (0.3.X+)

• dynamic_filter may placed over the motor-noise spikes to remove dTerm noise from gyro; However,
• dynamic_filter may also be placed above motor-noise spike to clean-up only high frequency noise.
• Often it is found that with dynamic_filter enabled, only one dTerm LPF is required.
• Prior to 0.4.0, it was found that with dynamic_filter disabled, two dTerm LPF’s were preferred if not required. (But this may vary with different aircraft, especially on Helio/Strix.)
• With 0.4.0+, dynamic dTerm notches may be enabled as the primary dTerm filter. It seems a single dTerm LPF still helps in this situation, but allows for a much higher cutoff.

Variables and Values

• Enable: feature dynamic_filter; Disable:feature -dynamic_filter
• Q (dynamic_gyro_notch_q) - Width of the dynamic per-axis notches. Higher value is a narrower notch, while smaller values are a wider notch. Smaller values (wider notches) are more latent than larger values (narrower notches). Range: 1-1000. Default: 350.
• dynamic_gyro_notch_count Range 1-5, Default 3. (0.4.0+)
• Min (dynamic_gyro_notch_min_hz) is the lowest value that a notch’s cutoff may exist. Range: 30-1000. Default: 150.
• Max (dynamic_gyro_notch_max_hz) [0.3.2+ / CLI only] is the highest value that a cutoff may exist. 0.4.0-Range is 400-1000. 0.3.0-Range is 600-1000. Default: 600.

Dynamic Filter on D-Term

• uses the analysis of the gyro dynamic filter to apply d-Term notches
• dterm_dyn_notch_enable Range ON, OFF. Default OFF.
• dterm_dyn_notch_q Range 1-1000, Default 400.

“Q” Example Graphic

Q (dynamic_gyro_notch_q) is a width. (note*: graphical representation only, not necessarily actual size.)

Dynamic Filter was formerly “Matrix”

• Matrix Introduction, by Paweł: https://youtu.be/7s8ZeP135uI
• How it Works, by Paweł: https://youtu.be/w0QsVIXYWCE

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