Discussions

Problem: Quad copter spins around itself

Posted by Hoang Cong Anh on September 1, 2015 at 12:48am

Dear all,

My name is Anh

I am assembling a new quadcopter using 3DR PX4 micro controller,on this morning I have tested my Drone and I saw that it flied and spins around itself, so I have to turn it off and, my quadcopter crashed

3691239918?profile=original

This is log info I get from Mission planner:

Size (kb) 10070.0341796875
No of lines 136430
Duration 2 days, 1:09:52
Vehicletype ArduCopter
Firmware Version V3.2.1
Firmware Hash 36b405fb
Hardware Type
Free Mem 0
Skipped Lines 0

Test: Autotune = UNKNOWN - No ATUN log data
Test: Balance/Twist = GOOD -
Test: Brownout = GOOD -
Test: Compass = FAIL - Large change in mag_field (429.15%)
Max mag field length (1346.02) > recommended (550.00)

Test: Dupe Log Data = GOOD -
Test: Empty = GOOD -
Test: Event/Failsafe = FAIL - ERRs found: CRASH FLT_MODE GPS FENCE
Test: GPS = FAIL - Min satellites: 0, Max HDop: 99.99
Test: IMU Mismatch = WARN - Check vibration or accelerometer calibration. (Mismatch: 1.16, WARN: 0.75, FAIL: 1.50)
Test: Parameters = GOOD -
Test: PM = FAIL - 55 slow loop lines found, max 9.98% on line 85540
Test: Pitch/Roll = FAIL - Roll (165.26, line 135281) > maximum lean angle (45.00)
Test: Thrust = GOOD -
Test: VCC = GOOD -

And, I also attached kmz log, if anyone know about my problem, please explain what happened with my drone and give me some advice

Thank you very much,

Anh

2015-09-01 11-02-00 113.bin.kmz

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –
Follow

Replies

            • Hoang Cong Anh > Bill Bonney September 7, 2015 at 6:11pm

              Dear,

              I also check the log file. I want to ask you 2 problems:

              - The mag filed value:

              3702885705?profile=originalDuring flight, this value is quite normal, it's only over the recommended value(550) after it felt

              So, that why I think the compass maybe still stabilize

              - The Yaw value:

              3702885536?profile=original

              I did not use yaw stick, but in the log you can see, the yaw and desired yaw look very similar. It changed from 0 to 360, it seems likely that I controlled it

              I also attached the log file, if you have time please help me to analyze it

              Thank you very much.

              Anh

              • Luc Maximilien > Hoang Cong Anh September 7, 2015 at 11:27pm

                Did you read what I wrote you ?

                I wrote to test your copter in stabilize mode disabling your compass and see how it flies.

                Look at the above graph.

                Do you see that in stabilize mode you do not have the compass and yaw variations ?

                If you have a GPS with integrated compass Neo7 bought from HK it is a defect of the unit.

                I have one and it is impossible to have the compass to work.

                You have to mount another external compass to solve your problem.

                • Hoang Cong Anh > Luc Maximilien September 21, 2015 at 7:41pm

                  Hi guys,

                  Sorry for late response,

                  After destroying so many propellers, I finally found the reason

                  My radio transmitter is not calibrated correctly, so it sent unwanted yaw signals to my drone. 

                  Phillip Schmidt  is right about effect of PID, it is not relevant to spiral flight

                  I can not fix the magfield value at my drone (~426 < 550 recommended), but it's problem is fixed and I learn so many things from you guys.

                  Thank you all of you for helping a newbie, like me.

                  Best regard,

                  Anh

              • Hoang Cong Anh > Hoang Cong Anh September 7, 2015 at 6:13pm

                Attached log

                2015-09-01 11-02-00 113.bin.rar

    • Hoang Cong Anh > Phillip Schmidt September 2, 2015 at 7:54am

      Thanks Phillip,

      Can I ask you a question.

      Do you think PID values can be a reason for my problem

      Because today I tested with different PID values and I saw that my quadcopter can take off vertically, although it still spins a little bit

      • Phillip Schmidt > Hoang Cong Anh September 2, 2015 at 5:19pm

        Spiral flight paths are almost always caused by a bad magnetometer calibration, so that combined with the fact that your log above clearly shows that your magnetometer is out of calibration, it is the obvious problem.

        Bad PID might cause the copter to oscillate or wander slightly, but it is extremely unlikely they will cause spin unless nonsensical numbers are used.

        • Hoang Cong Anh > Phillip Schmidt September 5, 2015 at 8:05am

          Hello,

          As you see in the log: 

          Test: Compass = FAIL - Large change in mag_field (429.15%)
          Max mag field length (1346.02) > recommended (550.00)

          This could be the reason lead to spiral flight path of my drone, so I refer this link: (http://copter.ardupilot.com/wiki/prearm_safety_check/) -> the recommended magfield is 530 for PX4

          Recently, I have tried many times to calibrate compass again,and also do compassMot, but this magfield value only changes from 426 to 430, it cannot reach to ~530

          Besides, after calibration, I receive different values of compass offset (you can see in attached files)

          They are the value of COMPASS_OFS_X/Y/Z and COMPASS_OFS2_X/Y/Z, I don't understand, I only use an external compass+GPS module for my drone, so what is COMPASS_OFS2_X/Y/Z?

          Could you show me how to correct the magnetometer?

          Thank you very much

          Anh

This reply was deleted.

Activity

Neville Rodrigues liked Neville Rodrigues's profile
Jun 30
Santiago Perez liked Santiago Perez's profile
Jun 21
More…