Hello,
I need to develop an auto heading feature for a small underwater vehicle (ROV). On board there are a rate-gyro and a flux-gate compass. I was able to use the rate-gyro for short-term heading stabilization, that is it tries to maintain the current heading in presence of external or internal disturbances.
Now I need to add the long-term heading stabilization, in other words an auto heading capability. The user sets the desired heading and the vehicle should reach and maintain that.
I tried with a standard PID using the compass signal as feedback but it's too slow and noisy for a fast recovery of the bow direction. After some tests I ended up with a trade off: with a weak control loop I have a smooth but inaccurate behavior, with a strong one a more accurate but instable behavior.
I'm sure I could improve the whole thing if I use the rate-gyro in conjunction with the compass. But I don't know how to mix both data.
In summary:
- the set point is a magnetic direction
- the inputs of the system are the current magnetic direction and the current rate of turn
- the output is a value proportional to the rate of turn needed to reach the set point.
May you suggest me a way to follow?
Thanks Marco