Newbie : Pixhawk, ArduRover, Throttle-Server very slow

ArduRover Rover 3.5
1

Hi folks,
I’m new with Ardupilot (and in general with FC) - and I do not found any similar forum entries for my current issue -

Behaviour:
MacOS, APM Planner 2.0.27, Pixhawk 2.4.8, installed firmware ArduRover 3.4.2., radio Taranis x9d+, receiver: FrSky X8R.
Taranis configured without any special things - no expo on channels a.s.o. Via switch arming/disarming configured and via 3-point switch changing flight modes.

Only for testing issues (first step), I installed two servos on my Pixhawk (ch1 Steering, ch3 throttle).

If I arm the system, it is possible with the steering stick to “move” the servo at normal speed - but if I do the same for throttle, the servo is extremely slow. I changed MIN/MAX values inside configuration and I tried to change SERVO_RATE - but without fixing my issue.

I have no idea what I’m doing wrong. If I check inside APM planner my radio (radio calibration), it seems every thing is ok. If I move sticks and switches I get response and see it inside this calibration screen.

As we say in german “Ich bin am Ende meines Lateins” :wink:
Hope somebody can help me - and as I said - I’m an ArduPilot-Newbie :smile: Cheers
Bernd

2

Have you checked the throttle slew rate?
http://ardupilot.org/rover/docs/parameters.html#mot-slewrate-throttle-slew-rate

1 Like
3

ahhh - YES - that was the kick :slight_smile: - it was set to 40, to understand the background logic, I changed to 1 and 100 - and than to 1000 - with 1000 it works as assumed.

Jeff - thanks a lot for this tip.
Any other pitfalls :wink: - which I have to know?

BTW: why and in which behavior this slew rate should be used?

1 Like
4

Good, glad it was that simple to fix!

Not sure of any other pitfalls just yet… we’ll address them as you encounter them.

The slew rate is useful if sudden changes in throttle can result in really harsh movements from the vehicle. It will basically smooth out the throttle commands. I use ardurover on boats, and that parameter is also useful for reducing something like cavitation on the propellers.

Once you get everything working, I suggest you play with that parameter to see how it effects performance.