Motor issues when running ESC calibration
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@Alex-Kushleyev Good morning,
Started trouble shooting this issue again with no change.
Under 4s battery power, all motors respond well to motor test, using slider in QGC, min to full throttle in Actuator tab.
Still no response other than "slow ramp up" when throttle is increased on RC Tx.
RDJ
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@rdjarvis , i wonder if you should try to load params for one of modalai standard vehicles and change the min/max rpm to match your setup (4000min, 40000 max, or you can be a bit more conservative, say 30k max for this test). Then try with manual control but with propellers OFF. The issue you are seeing is coming from Flight Controller so it should not matter of props are on or off for this test. But you should keep them off if using params from a completely different vehicle / tune. But at least you could then see if FC lets you raise the thrust normally..
Basically, no change to esc, props off, choose our standard vehicle params for 4s and try to raise thrust, check the px4 log.
If you see strange behavior like strong oscillations, you should stop the test.
If the thrust control is ok, then you can compare your params more carefully with our standard params and see what causes this behavior.
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@Alex-Kushleyev I am going to upload FPV_REVB. unless you recommend another.
RDJ
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@rdjarvis , yes but change the vbatt since fpv revb is 6s. That is probably closest to your config
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What effect does the aO,a1, and a2 (pwm_vs_rpm curve) have on overall throttle response for FPV 4n1 ESC? in the FPV_RevB the a0 value is -161.0826?
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Also, sinusodial value is 0 in FBV_RevB, I will change this to 1.
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@rdjarvis , please do not change ESC params that you tuned for your motors. I meant use px4 params from another vehicle.
The a0.,1,2 are params for feed forward term in rpm control. The esc seems to be working fine in your case (rpm tracking is good).
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copy all, will do.
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@rdjarvis , sorry for confusion, please do not change esc params but find px4 tuning params for our fpv vehicle and try to load it to your vehicle (change 6s vbatt to 4s in px4 params since fpv vehicle uses 6s).
Test without props because attitude control is going tonbe much different for fpv vehicles vs yours. But you should still be able yo see thrust response in plots.
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you can find our FPV params here :
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We kept the custom ESC config for the 2203.5, and uploaded px4 FPV_RevB_v4.
Motors are more responsive in all channels, Throttle channel still conducts a "ramp up", but more aggresively when RC Tx input is applied.
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@Alex-Kushleyev No actionable response from throttle.
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Throttle input is being "ignored" regardless of RC Channel input, same response (slow ramp up) when armed in any flight mode (Manual/Stab/Pos etc..) and throttle is increased, even when RC Channel is changed (1,2,3,4).
Motors respond correctly with pitch, yaw, and roll inputs.
PX4 FPV_RevBv4 params are uploaded, switched to 4S and put min/max RPM to 3000/40000.
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From the GCS, executed "take-off" command in "Position Mode" with props off. Motors smoothly increase. I "hand-flew" it up to 1m and UAV was adjusting for small movements correctly.
Executed "Land" and "hand-flew" it to the deck, landing detected and disarmed.
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@rdjarvis , interesting. Can you please share a px4 log from that position mode test?
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@rdjarvis , yes in this mode, the vehicle seems to be responding to thrust commands and motors are tracking rpm well (even though without props)
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@Alex-Kushleyev I agree, what do you think the next troubleshooting step is for this issue?
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Also another observation.. remember in manual flight, it seemed like instead of responding to the throttle stick, the actuator outputs were going up slowly in a ramp -- i just double check that seems to be a response to small rill/pitch deviations that happened, so it seems that the thrust stick is COMPLETELY ignored, which is what you have suggested.
Now, the position mode goes through the same control pipeline except the hight is controlled using a high controller, as opposed to your radio. However, the commands are still going through the mixer that converts and thrust, roll, pitch, yaw commands to motor outputs , so that seems to be working correctly.
Based on that, it seems the issue is somewhere between the Actuator controls and motor outputs, which is the mixer, right? Actuator controls data shows the desired thrust (up) goes up, but motor output does not reflect this. Maybe we can look at the px4 source code for the mixer which maps the actuator controls to motor outputs.
I just noticed that you have parameters
CA_ROTORx_AZ(for x =0,1,2,3) set to 1, but default is -1, which would mean that you are saying that thrust from this motor goes up, not down? -
@Alex-Kushleyev Thanks Alex, We will test it out. In the meantime my team will be sending the first FPV 4n1 ESC back, so you can investigate onsite.
Thank you,
RDJ
