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Servo Trim - pendulum rudder

I use the Pypilot to control a pendulum rudder system, which then moves the ship's rudder.
The whole thing runs on a geared motor and has no rudder position sensor.

Basically the hardware works, but there are still a few tuning problems.
The positioning time of the system is quite short (approx. 3-4 seconds on BB to SB).
Do not adjust the rudder very sensitively.

In my opinion, the steering impulses should be much shorter in order to be able to steer more precisely.

I still have a few problems understanding the necessary adjustments.
What means e.g:


Does anyone perhaps have experience with such a combination?
You might want to reduce servo.speed.min or servo.speed.max to make the motor move slower if needed. You can reduce the period also to get shorter impulses, but the stable autopilot only uses 10hz, so you can only really use periods of 0.2 0.3 0.4 etc... The next version I bumped to 20hz. You might want to make the slew speed and slow higher so the motor starts and stops faster. Usually leave servo gain to 1 and adjust the other gains, but you could also reduce this to a value like 0.5 (equal to making all the gains half what they are)

You will never get the same precision of steering using a pendulum like this, because of lag and play in linkages, but it will use significantly less power of course.
Hi Sean,
thank you for your answer.

I have already tried to reduce servo.speed.min/max. Unfortunately the torque is not enough then. There I will
probably have to use a gear with a higher reduction.

The pure steering time for such a configuration is very short (from hard starboard to hard port) but there are
there is a slight delay in the reaction time.

I could imagine that it helps to give a short control impulse, and then wait a moment to see the reaction of
the boat. Is there a setting with which such a delay could be achieved?

That the steering behaviour will not be like with direct rudder control, I think so too. But I could imagine,
that it should work better than with the wind vane.

Besides the low power consumption, the much lower noise emission of such a system would also have to be considered.
Could you try increasing the slew speeds? This might give you the quicker movement you are looking for. You might have to increase the max current as well as this creates a higher current spike.

It sounds like you might want to try a higher gear reduction if possible especially if the torque isn't enough when reducing the min speed. 3-4 seconds is really fast, you could even double this and be ok in most conditions.

The alpha image maybe works better since it uses 20hz, so you could then try nd use a lower servo.period of 0.2. There are a lot of variables to play with.

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