How to adjust Speed Throttle auto mode, Arduplane 3.9.4

ArduPlane
1

Hi,

Please advise to adjust airplane speed in “Auto” Flight mode ? Currently I’m using Arduplane V3.9.4 and Pixhawk Flight Controller.

Currently I only adjust the cruising speed with change Throttle parameter in basic tunning.

Could i adjust the aircraft speed with set “Do_Change_Speed” value in Waypoint without air speed sensor ?

I’m using Zeta Phantom FX-61 right now :slight_smile:

Thanks

2

Yes it’s described here :
http://ardupilot.org/plane/docs/common-mavlink-mission-command-messages-mav_cmd.html#mav-cmd-do-change-speed

|Command Field |Mission Planner Field |Description|
|param1 |Type (0=as 1=gs) |Speed type (0=Airspeed, 1=Ground Speed).|

Also consider using throttle nudge in params if you have no airspeed :

THROTTLE_NUDGE: Throttle nudge enable

When enabled, this uses the throttle input in auto-throttle modes to ‘nudge’ the throttle or airspeed to higher or lower values. When you have an airspeed sensor the nudge affects the target airspeed, so that throttle inputs above 50% will increase the target airspeed from TRIM_ARSPD_CM up to a maximum of ARSPD_FBW_MAX. When no airspeed sensor is enabled the throttle nudge will push up the target throttle for throttle inputs above 50%.

Values
Value Meaning

0 Disabled
1 Enabled

http://ardupilot.org/plane/docs/parameters.html#throttle-nudge-throttle-nudge-enable

3

Many thanks for your advise bro.

I’m still confusing about the Throttle_Nudge mean:

This mode, will use “Throttle Input” in auto-throttle mode to nudge.

Does it mean, that the Flight Controller will use Throttle Input (Ch-3) from RX Receiver as a speed reference ? So we could adjust the speed manually from Remote Transmitter while the mission (auto mode) running ?

Please advise if i’m have miss perception. Thanks

Regards,
AndriaG

4

Yes. 50% throttle will demand TRIM_ARSPD_CM, and 100% throttle will demand ARSPD_FBW_MAX.

5

Thanks Nathan,

Seems I have to try to deeply understand these parameters.

One question again, so to use this parameter, Throttle_Nudge should be enabled then start to fly the plane. When the plane fly and ready to do mission, we switch to “Auto Mode” to tell flight controller to execute the mission.

At this time should, I cut off the throttle or let it 50% ? If the plane fly slower that speed that i want, then should I slide up the Throttle stick to increase the speed and vise versa if the speed too fast.

Does my statement true ?

Thanks

6

If you move thr to the lowest you calibrate, it will use ARSPD_FBW_MIN

7

Ok, it’s clear now. I will do experiment with it :slight_smile:

Thanks all

8

Hello guys!
I am using herelink remote (central throttle stick) with plane running ardupitlot 4.0.4 using an airspeed sensor. I set Trim_arspd_cm at 13 m/s and Throttle_nudge is enable (1). Ardupilot describe that below: “When enabled, this uses the throttle input in auto-throttle modes to ‘nudge’ the throttle or airspeed to higher or lower values. When you have an airspeed sensor the nudge affects the target airspeed, so that throttle inputs above 50% will increase the target airspeed from TRIM_ARSPD_CM up to a maximum of ARSPD_FBW_MAX. When no airspeed sensor is enabled the throttle nudge will push up the target throttle for throttle inputs above 50%”
But whenever I enter cruise mode with herelink stick in neutrel, the plane does not fly right with target speed (it fly faster!) So what was wrong? Pls help me. Thanks!
P/S: I set Arspd_FBW_Min at 12 m/s and Arspd_FBW_Max at 25 m/s, Trim_arspd_cm at 13 m/s.