Position/Altitude Hold not working

ArduCopter
1

Hi, my drone is running pixhawk 6c mini on mission planner and I have been able to successfully fly the drone around manually, however whenever I switch to both altitude hold and position hold. The drone shoots up. I have not let it continue up so I do not know how high it will go.

I tried to decrease the fence of the drone to 0 meters minimum and 25 meters max, this did not work.
I added vibration pads under the flight controller to prevent vibration interference and this helped to control the drone better but I am still having the same issue.

I am assuming its either vibration interference or a simple parameter setting that I have not figured out yet. Any advice would be appreciated.

Thank you.

2

10_11_25_Parameters.param (18.3 KB)

Here is my parameters file.

3

Post a link to a .bin flight log where this was witnessed.

4

Under which flight mode?

7

stabilize mode, then i try to switch to alt hold.

8

Access request needed.

9

just gave you access

10

What is your Pixhawk 6C drone’s weight?
I think your drone may be overpowered.
You can try to secure a dummy weight to see if it improves.
Take note of your drone’s centre of gravity when adding dummy weight.
Thrust auto learn will not happen if the learned value is below 0.125.

By the way, your drone is fitted with a 9" or a 7" propeller?
If 7", change MOT_THST_EXPO = 0.54.
The rest of the initial parameters look like a 7" drone.
Please do not disable any arming check.

EK3_SRC1_POSXY,3
EK3_SRC1_POSZ,1 # try default first.
EK3_SRC1_VELXY,3
EK3_SRC1_VELZ,3
EK3_SRC1_YAW,1

image
image1279×868 12.7 KB

11

This craft will never fly with default Rate PID’s and vertical acceleration controller gains. MOT_SPIN_MIN at default is a problem also. The outputs are nothing but oscillation.

RCout
RCout1202×353 88.6 KB

And, you would have an easier time tuning it if you used a higher capacity battery for additional weight. From this log it’s difficult to determine hover thrust but it could be as low as 0.02.

No argument there key parameters are at default:
Tuning Process Instructions

12

Thank you for the input.

I have MOT_THST_EXPO = 0.54. What should this value be changed to? Decrease it to .45?

Updated EK3_SRC1_POSZ to 1.

Updated MOT_SPIN_MIN to 0.20 from 0.15

I cant fly it today but I can add some weight to the drone and try to edit the PIDs. Ive never tuned a drone before but ill reference the tuning process instructions link to give it a try.

13

Use Mission Planners Initial Tune Parameters screen.

Based on what?

14

I tuned the initial parameters again and i helped a little bit. I also started to look into the extended tuning metrics but haven’t changed anything yet - haven’t had much time. Switching the MOT_SPIN_MIN to .25 helped a lot with being able to rotate the drone.

This morning I added weight to the drone and flew it up around 20 ft and for some reason I lost control and it kept on ascending up. This has only happened once before. Any idea what could be causing this?

Here is the link to the .bin file.

It reacted the same as when I switch the drone into Althold mode. Just a incontrollable climb.

Thank you

15

Again why? The Hover thrust is more like .06 This answers your question “any idea what is causing this”.

Anyway you have massive outputs oscillation from default Rate PID’s and Vertical Acceleration Controller gains.

RCout
RCout3351×1030 376 KB

With your limited level of knowledge I think the best approach for you is to reset to default and use the Methodic Configurator
Or start here and get into it: Tuning Process Instructions