Relationship between tuning and Noisy Sensor Data

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Scott H
Posts: 119
Joined: Wed 24. Jun 2015 4:03:28

The manual states: RPM Sensor data are too noisy:

RPM readout is very unstable and are oscilating more than +/- 100 RPM. Data from the sensor are unusable for the Governor. Use additional shielding and mount a ferite rings. Increase value of the RPM Sensor filter parameter in the Expert settings

If the "rpm sensor data are too noisy" message in the log is when the RPM's oscillate +/- 100 rpm's does that mean we should tune the governor first before trying to reduce noise?
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jasc
Posts: 61
Joined: Fri 20. Aug 2021 6:12:26

It's always best to reduce electrical/mechanical noise first. More filtering adds more delay and reduces effectivness of PID controllers
Scott H
Posts: 119
Joined: Wed 24. Jun 2015 4:03:28

Hey jasc,
While I agree it's always better to reduce noise to minimize efforts of filtering downstream. The "Noisy Sensor Data" actually means something more than just noise and this is what I want to understand. As mentioned above, according to the manual, any variation of over or under 100 rpms will create a record in the log of "noisy Sensor Data".

So there are three meaning to this "noisy sensor data": an abundance of noise, as well there is a potential for bad governor settings, as well as poor engine tuning. All of these conditions will result in "noisy sensor data" in the log.

Another natural conclusion then is that the log record of "noisy sensor data" may in fact not have anything to do with EMF noise or any kind of electrical interference.

Just looking for clarity if there is any.
ZeXx86
Site Admin
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Joined: Mon 29. Apr 2013 16:06:44
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Hello,

noisy sensor data mean that the reading is unstable.
This can be also caused by too high gains of the Governor.
In other words, if sensor is working well but governor is tuned badly, you can get the same message.

If you are uncertain, it can be helpful to hover the model with the lowest possible gains or at least with default governor gains.

Usually when sensor is working incorrectly there are problems with Governor engaging. So that it will engage, not engage or maintain wrong RPM. Each flight you will get different results.
Spirit System developer
Scott H
Posts: 119
Joined: Wed 24. Jun 2015 4:03:28

Tomas,
Will a noisy rod end inside the engine also cause an unstable rpm sensor? as in a log record of Noisy Sensor Data.

Scott
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