Hello guys,
I just noticed a weird thing happening on my arducopter. I was doing some tethered testing and the quadrotor seemed to work fine. Then suddenly I could see motor 4 stall and therefore the quadrotor flip. I thought it might be the calibrations so I redid all of that. Then I tied it up again and tested. This time again the motor did it. So I pulled up the logs:
MOT: 1329, 1363, 1306, 1342
ATT, -234, 165, 1768, 407, -157, 20
MOT: 1298, 1378, 1319, 1349
ATT, -143, 276, 1803, 74, -475, 26
MOT: 1332, 1346, 1288, 1382
ATT, -91, 354, 1815, 50, -147, -64
MOT: 1326, 1336, 1329, 1357
ATT, -145, 273, 1811, 307, -247, 45
MOT: 1312, 1372, 1310, 1358
ATT, -229, 169, 1784, 200, -332, 80
MOT: 1327, 1367, 1298, 1364
ATT, -182, 143, 1765, -149, -571, 49
MOT: 1364, 1336, 1285, 1399
ATT, 140, 806, 1939, -653, -1809, -678
MOT: 1351, 1221, 1240, 1600
ATT, 785, 2273, 2584, -1507, -2500, -1057
MOT: 1420, 1207, 1230, 1730
ATT, 1558, 4025, 3207, -1582, -2500, -1369
MOT: 1440, 1207, 1304, 1804
ATT, 2293, 5338, 3825, -2066, -2500, -1686
MOT: 1506, 1207, 1332, 1832
ATT, 3322, 6135, 4695, -2042, -2500, -2103
MOT: 1477, 1207, 1332, 1832
ATT, 4654, 6104, 5832, -2448, -1828, -2500
MOT: 1363, 1207, 1437, 1801
ATT, 7245, 5642, 7332, -2500, -2500, -1355
MOT: 1077, 1077, 1077, 1077
ATT, 10786, 4339, 9601, -2500, -2500, -2005
MOT: 1077, 1077, 1077, 1077
ATT, 14532, 1867, 10747, -2500, -2500, -657
If you noticed the last few 'Motor' values suddenly shot up for motor 4 and reached 1800+ which is the max. In reality the motor had stalled... I then stopped the throttle and therefore you see the 1077 values. I need someone better than me to advise on what could be going on here.. Just a history that I didnt really observe this quite frequently. It happens every so often.
Any ideas?
Thank you
Ammar
Replies
Thanks Ellison! I ll try switching them around now and see where the problem lies..
BTW, does anyone know where I can find details on the different logs that I can collect. For example: I am not sure what each of the 8 values PM means. I looked up in the code and it says imu.adc_constraints or dcm.get_health.. However what do these convey??
Similarly for the Atiitude readings, I understand from the code that the first three are roll, pitch and yaw. However I do not know what rc.servo_out is??
Those are the PPM values sent to the motor. It goes up to max because the motor is stalled, and the APM increases the PPM to that motor thinking that side needs more power. Is the motor or esc that's stalling getting hotter than the others, after this happens?
The same thing happened again.... Here are the logs:
MOT: 1337, 1349, 1381, 1313
ATT, -61, 156, 1566, 38, -636, 132
MOT: 1356, 1362, 1270, 1396
ATT, -113, 181, 1564, 293, 202, -30
MOT: 1315, 1373, 1370, 1330
ATT, -164, 173, 1565, 72, -338, 0
MOT: 1340, 1354, 1314, 1380
ATT, -125, 224, 1577, -63, -230, 26
MOT: 1356, 1344, 1323, 1369
ATT, -78, 328, 1628, -152, -1024, -270
MOT: 1337, 1307, 1274, 1478
ATT, 467, 1406, 1981, -1513, -2500, -857
MOT: 1438, 1207, 1207, 1707
ATT, 1236, 3081, 2690, -1441, -2500, -1215
MOT: 1424, 1207, 1272, 1772
ATT, 2054, 4734, 3406, -1986, -2500, -1653
MOT: 1485, 1207, 1332, 1832
ATT, 2891, 5809, 4167, -1733, -2500, -1966
MOT: 1476, 1207, 1332, 1832
ATT, 4127, 6120, 5200, -2040, -1944, -2488
MOT: 1454, 1207, 1444, 1832
ATT, 5896, 5836, 6439, -2500, -2500, -1079
MOT: 1383, 1207, 1207, 1597
ATT, 9294, 4896, 8227, -2500, -2500, -1942
MOT: 1077, 1077, 1077, 1077
ATT, 12795, 2901, 9978, -2500, -2500, -1676
MOT: 1077, 1077, 1077, 1077
ATT, 16241, 817, 10885, -2500, -2500, 364
Motor 4 gets a really high PWM when it stalls.. What could this be ?