Auto Height Fucntion

Today we had our first outside test session. We are working on batteries and strugling a bit with power so we only had about 30 minutes in the water but everything seemed to work quite good.

One of the things I don’t really understand is the althold mode. We have set buttons Y and B on our controller to change between mode 1 and 2. In the software this causes to go from manual to learning mission mode. In Manual mode we can go up and down using the throttle control and when we switch to learning at a certain depth it keeps that depth very well. However in Learning mode the throttle control doesn’t seem to have any effect. We can control the height.

Does this supose to work like this or should you be able to change depth in althold mode?

We would still like to limit the amount of power going to the thrusters. We have tried changing the ATC_RAT_YAW_… PID parameters but this doesn’t seem to have to much effect. Would it be possible lower the power output in another way?


I’m glad that everything is going pretty well so far.

The althold mode does allow you to change depth, but the controls for that are not great right now. Basically, the throttle joystick becomes a “depth” joystick. I’ve been meaning to look into it for a while because it does not change depth very well when you do that.

To limit the amount of power going to the thrusters you should be using the gain control. There are joystick button options for gain increase and gain decrease. The default gain is 50% meaning that the thrusters will only go to 50% power max. If you want less then there is a 25% option. The current gain value prints out on the “Info View” when it is changed.


In depth hold mode, the throttle stick changes the target depth. The rate at which the target depth is adjusted is proportional to the displacement of the throttle stick from center. Look at the parameters PILOT_VELZ_MAX and PILOT_ACCEL_Z, these will also determine how quickly that target depth changes.

Also, a note on the gain. These constrain the inputs to 50% maximum, the output to the motors will still increase to full power in an attempt to stabilize, if necessary (like if you push on it to disturb it). I think this is the case. Rusty, can you confirm?