APM Autopilot problems

Hi there,

Nowadays I am working on APM and autopilot. I can fly stabilze mode almost well. The problem is heli’s tail aims to torn right and it increase when I increase throttle. I try to control with radio’s trim. But it is changing with throttle. In addition heli aims to shift left, right before takeoff. It seems that yaw sensitivity should be increased like rate_yaw_p, right? or maybe Magnetometer problem I dont know.

On the other hand, I tried RTL and auto mode but I couldnt succeed. In auto mode heli rolled right unexpectedly but hold the altitude and didnt go first waypoint and I switched on stab mode swiftly. It maybe caused because of a little shaking that I omit because of rate_roll. Afterwards, I tried RTL and at first 10 seconds, it looked everything was right and heli started to turn me slowly. But then it rolled left and crashed before I took control.

So after a few experience like above, I decided to make a fly in stab mode extensively. Today I did and there was no shaking though rate_roll and pitch values were 0,75. But the problem was heli tail’s aim to turn right was increasing when I increased throttle.

Totally, I have 2 questions.

First, Which is the best way to prevent heli tail’s aim to turn right and also prevent shifting to left.

The other question is What are the main points and necessary parameters to succeed auto mode, RTL and hover modes. LEfevbre recommended me to use external compass but it cost me lots of time. I would rather to succeed that with APM’s internal compass if it is possible? which points should I check primarily? IS INS offsets are critical too much?

Thanks for your patients in advance.

What is your rate_raw_P at? Yes I would adjust that if it feels like the tail is not responding, I tend to think of that like a gyro gain.

Have you tuned alt-hold yet? I would start by tuning alt-hold since that logic is used in loiter. Once alt-hold is working great, move on and tune loiter. You shouldn’t have much in the way of simple stability problems with compass interference, it normally presents as a toilet bowl effect while in your loiter.

Hi netflow,

Thanks for reply. I attached all my settings. I am not well about them because I couldnt test extensively. Now I can fly almost well in stab mode But I know little about loiter. I just tried altHold and tried auto mode by defining waypoint that resulted crash :slight_smile:

Now I am concerning about I should need some external magnetometer or compass that I am not well about their settings and I have limited time. So I wish to find a way to make internal sensor settings well and can make a small auto flight. I mean I hope it is possible to fly with internal sensors(magnetometer, compass, accelometer) that will earn me time. I suppose I made all sensor settings well. I also checked from the videos and forums on internet. LEfevbre suggest me to buy an external compass and if it is must, I need to give an order immediately. Do you think it is easy to make it with internal sensors?

Thanks, best wishes.

Your Rate Yaw I and Imax are almost certainly too low. And your Rate Pitch and Roll Imax are probably too low as well.

Hi Lefevbre,

So I will increase them. Do you have a suggestion? and is that one of the primary factor to fly in althold or other auto flyings?

On the other hand I gave order as you recommend: store.3drobotics.com/products/3d … th-compass

I hope it will help me to fly in auto mode shortly :slight_smile: One more thing, could you please check my params above if something is wrong for you ?

thanks, have a nice day.

It’s really hard to make any recommendations without any log data. So I was just pointing out a few things based on what little info you have provided. The yawing is almost certainly due to problems with the yaw Rate tuning.

@Lefebvre, Thanks.

Is there anyone that can say me what is wrong with my settings. I can fly in stab mode well but I know little about automode, alt_hold and loiter. Is there any critical change to succeed loiter or mission with 3 waypoint? Thanks.