LibrePilot Forum
Users => Vehicles - MultiRotors => Topic started by: Aung Ko on October 22, 2018, 08:20:51 pm
-
My quadcopter, Q450 doesn’t fly gradually when I increased throttle. It’s is like too responsive. Where can I Tune this? I tried calibrating ESC with GCS, still don’t work. Even worse, motor increased its self and hit the ceiling. I am not a very bad pilot. Already built 2 quad and flied well. Please help me, any answers? sources? Link? (modified by TOC to use youtube.com instead of youtu.be) https://www.youtube.com/watch?v=zOErTrIO0CY
-
How much throttle stick was that? What happens if you give 1/10th stick? Same thing?
Is this CC3D or Revo? How did you tune the PIDs?
I would guess either:
- Input Throttle min/neutral/max is not good. It should usually be about 1000/1040/2000 (not 1000/1500). Sbus numbers a little lower.
- D term of PID is too high and you are getting D term oscillations (invisible oscillations).
- Output mins/neutrals/max are not good (should usually be 1000/1080/1900) or ESCs are not well calibrated.
-
I am using CC3D atom. The pos of throttle sticks was just Min. I didn’t know much about PID, so they were all in default. Throttle Input is 997/1045/1990
Output config is 1000/1043/1900
I think it’s about PID because I found that In flight mode 3 which is rate and manual. The motors spin well...
Here is the video
https://m.youtube.com/watch?feature=youtu.be&v=mXDBW1f_oqE
I don’t know how to tune PID, so if you have any good document or video please give me or any answers?
-
Do all your flight modes use the same PID bank? Input -> Flight Mode ... page
You could try setting all your D terms to zero for a test. You could also cut all your P's and I's in half at the same time. just for a test (it will be very mushy, hard to fly, but throttle may work well).
If Rate and Manual works, what is the mode that does not work?
If you attach your settings UAV file, it would help. File -> ExportUAV...
-
I really don't know where is I where is D and where is P. I don't know how to tune. Here is my UAV file. I just reset the vehicle setup again. But didn't solved the problem. In throttle neutral motor spin more than proper speed. I have no idea what to do next. Please help. Here is my file
-
You need to check the option "Zero the Integral when Throttle is low" in Stabilization tab > bottom of page.
(https://forum.librepilot.org/index.php?action=dlattach;topic=4472.0;attach=7841)
-
Already did and still not fixed
https://www.youtube.com/watch?v=gIzE5bEsdyI
-
Try the settings file attached and try flying outdoors, indoors testing in never a good idea.
If you increase Throttle slowly the "Zero the Integral when Throttle is low" option has small effect, especially if I terms are high.
-
I have not test outdoor flight ye because it’s already Night in my country. That’s what I get when I import the UAV file you gave. Still the same answer. When I increase throttle, motors spin fast and reach to like 30% it’s self. But in flight mode 3 motors responsed well. So, I think I have to tune ESC and throttle well. But I don’t know how to tune. Here is my demonstration video...
https://www.youtube.com/watch?v=iUuwE14HupA
-
I saw that video, the situation seems same with mine. I need to go out and test bravely 😁 first
I will reply after I fly
https://www.youtube.com/watch?v=WbRyN048BfU
-
Motors increasing slowly in Attitude mode is normal when on the ground or with props off. When Attitude (bank angle) is a little wrong, it speeds up some motors to make the Attitude correct. Because it is not in the air, it does not move, so it tries harder and harder. If props are on and it is flying, then the first smallest motor change will cause the Attitude to change and it will not have to spin up faster and faster.
In Rate mode it does not care that it is not perfectly level so it does not spin the motors faster (a simplification of what actually happens).
I think maybe that you don't actually have a problem, but you are not used to controlling the quad throttle. :) The first thing you must learn is how tiny tiny changes (like just 1mm) in the throttle is the difference between slowly (which is what you want) climbing and slowly descending. In order to keep it at waist high, you will always be adjusting the throttle up and down by the tiniest amount possible, just like when driving a car on a straight road, you use the smallest amount of steering to keep it centered in the lane.
As long as your quad is not super super powerful then reducing the throttle to say 1/4 should cause it to descend (with motors still turning); and as long as your quad is not weak, then increasing the throttle to 3/4 should make it climb. The key here is to find the place where it is not climbing or descending and from there, only use maybe plus or minus 2mm of throttle stick movement. If you use more, you over control. As @f5soh said, do this outside until you "get the feel of it" and can control altitude.
-
I am not pretty sure yet that it is an error or normal because as I said I have built 2 quadcopter and I flied well. I am sure I am not bad at handling throttle control. I first built a quad with QQ super and other with CC3D atom which is the one I am using now. With the previous CC3D one, I was able to fly well indoor. Without tuning anything only with default setting. Now I did the same, setup same motor and ESC values, same frame but the present one doesn’t response same as the old one. So, I thought it is a problem. Because typically it should fly well indoor right? I will try outdoor flying and I will reply the result. Thank you for all your help. I attached my UAV setting file. Please I request you to view it if something is wrong. Thank you all for all your discussion and I will stay tune.
-
It sounds like you have experience. That leaves 3 things I can think of:
ESC calibration: You said you did it, but here are instructions you can try:
https://librepilot.atlassian.net/wiki/spaces/LPDOC/pages/12058743/ESC+Calibration
FlySky transmitter has a problem that can be fixed. Here is a way to see if you have the problem and how to fix it:
https://www.rcgroups.com/forums/showthread.php?2145070-New-Flysky-FS-i6/page117#post38300831
More powerful than you are used to will make altitude harder to control. You can add some "expo" with a curve on throttle, but beware that it will not be centered on center stick, but on hover power location, where ever that is.
------------------------
You can plug in USB and flight battery and turn on transmitter and go to GCS Input page (or HITL page or System->Objects->ManualControlCommand) and watch to see if throttle responds correctly.
Is it possible that you have some throttle curve or throttle mode set in the transmitter?
-
I said I did ESC calibration was according to the exact same link that you have mentioned. My throttle curve from transmitter was normal, linear graph. HTLM aslo work correctly. Do you mean try to add expo to throttle curve mean change output throttle curve ( vehicle setting) or on thrust PID scaling (stabalizing advances setting) ?
-
My throttle curve from tx
And tx display showed correctly
-
Any place you can make a setting for the throttle curve would work but this is an ease of use change. I would make sure to fix any real problem before putting a curve on throttle. When making a throttle curve you need to make sure that zero throttle stick still means zero throttle, or you can't arm, etc. GCS Vehicle page has a throttle curve where you could set it too.
Another: vibration can also cause similar problems. Balance your props!!! !!! (and motors too is always good, and make sure your prop shafts don't wobble)
Another thing I forgot about: One set of many cheap eBay ESCs came with old firmware and did exactly this; jump up with low throttle and sometimes require shutting motors completely off at zero throttle to get it to come back down. Flashing the latest firmware immediately fixed the problem. Now days when I buy cheap ESCs I first test for dead in case they need to be sent back for a refund (never happened yet). I always flash the latest firmware before installing them. This system works well for me.
-
It is not working. When I increased throttle it increase too much and when I decrease it suddenly drop. Look like it is not sensitive too much it is not response enough. Any, possible answers?
-
ESC brand is skywalker
-
Here is my final outdoor test...
https://www.youtube.com/watch?v=QHGl-TXjfl4
-
Watching again all the videos I see that it is stabilizing and that is good. You know how to successfully control throttle and that is good. How much throttle stick does it take to lift off? Less than one fourth?
The other quads that you have flown, did they have a spring on the throttle stick? Did they have sensors to help you control the altitude? Flying without altitude sensors needs very small corrections on the throttle stick. Forgive me for saying, because I don't know your experience. You can't just set the throttle stick to the middle and expect it to hover. You must find the place where the power is correct for hover. Sorry if you know this already, but I can't tell how much throttle stick you are giving.
1mm is the difference between climbing slowly and descending slowly. Moving the stick down 10mm from hover power makes it fall quickly. In a hover, you will be always moving the throttle tiny amounts. There is no stick position where it will stay at that altitude.
I actually have 3 of the eBay clone of those quadcopters. :)
It is very important to balance your props. If you have not balanced them, please do. :)
With battery and USB plugged in, go to Input page in GCS. Switch transmitter on. Do not arm. Move the throttle stick. You should be able to see the GCS Throttle slider move with the transmitter throttle stick. There will be a time lag (maybe one second) from when you move the transmitter stick to when you see the throttle slider move. Just make sure that a very low throttle stick makes a very low throttle slider. What would be bad is if the slider jumps way up with just a very small movement of the transmitter stick.
First of all, battery size: All of the following discussion assumes you are using a 3 cell LiPo. If you are running a 4 cell LiPo, the props should be about 2 inches smaller than I discuss.
motor and prop size:
My small motors are 2212 (internal size) which are 2830 external size. The important thing is that they are KV1000. My large motors are 3530 external size and KV1100. I run 10x4.7 props on all of them. It looks like your motors are 2212 or maybe larger, that is OK. The KV is the important part. What is your motor KV? It also looks like you are running larger props than I am. If your motors are about KV800, I guess you should be running about 11x6 or 12x5 props. If your motors are about KV1000 you should be running about 10x5 (10x4.5 or 10x4.7) props. If your motors are KV1200, you should probably run 9 inch props. If your motors are KV1500 you should run about 8 inch props.
It looks like you are running perhaps 11 inch props (from what I see), and the prop pitch even looks fairly high, like maybe 11x6 size. 11x6 props are too big if your KV is 900 or higher.
ESC calibration: I assume that you are still running the settings in Aung2.uav, so the CC3D settings that relate to motor speed are OK. What I am going to suggest is dangerous if not done very carefully!!! I suggest that you tie it down like you did before. Leave the props on. Plug battery in. Plug GCS/USB in. Transmitter not needed. Go to Output page and click Test Outputs. Very carefully move one slider SLOWLY to the right until a motor starts. At any time you can press the Home key to move the current slider to the off position. (The End key is very bad. It moves the slider all the way to full power. Do NOT use it with props on!!!) When the motor starts it should be very slow. You should be able to slowly move the slider up about half way before it has enough power to lift that corner of the quad. Stop that motor (you can use the Home key for that( and test the other 3 motors the same way. If any motor is too fast at low speed, then you need to re run ESC calibration. You can also test all 4 motors at once. With all sliders all the way off (left), click the Link check box for each motor. Now you can slowly move one slider and all sliders will move. It should not take off till about one fourth of the way up. There is no stabilization when you test it this way.
The previous test shows if the ESCs are calibrated well enough to allow low throttle.
I see that the PIDs are slightly modified because of previous tests. You should probably set them back to default values, but I don't think that is your problem.
Calibrations: Has Level calibration (Attitude page) been skipped? That isn't your problem, but it shouldn't be skipped.
-
I will reply your discussion very detailed later,
Here is my quick question...
I connect the wire as GCS said but when I searched on google and they did the other way... but differences is that they are using CC3D and I am using CC3D Atom... and different Reciever
I am using FS iA6B
I connced the throttle wire which is 3wire (S, +, - ) to channel 3 because throttle is always on channel 3 right? And roll on ch 1, pitch on 2 and yaw on 4 etc...
So, here is my diagram of how I connected and
What GCS showed and what I fond on google...
-
No difference between CC3D and CC3D Atom.
I connected the throttle wire which is 3wire (S, +, - ) to channel 3 because throttle is always on channel 3 right? And roll on ch 1, pitch on 2 and yaw on 4 etc...
When you run the setup program and wiggle each stick when it tells you to do so, it determines which wire does what. As long as GCS Input page (battery plugged in, USB cable plugged in, transmitter on) shows that each stick controls what it should control then it is correct.
You have used a manual throttle before and have practice that you must constantly adjust throttle by about 1mm or so? :) Sorry to ask.
What firmware are your ESCs running? If running stock firmware then there is an option for startup speed. SimonK and BLHeli firmware don't have this problem. Slow is used by one blade helicopters. Quad copters MUST use the fastest setting. You can test with props off (very very important) and "Test Outputs" as before. Press End and all motors should immediately be running at top speed. If even one motor takes much more than 1/2 second to get to top speed, then your ESC speed setting may be wrong.
-
I think this is because of my wrong setup. Here is my set up
Q450 frame
2212 1400kv
skywalker 30A ESC
1045 props
May be 1400kv with 1045 props get too much thrust
Should I change motor with 1000kv
-
I started thinking that my motor and props are not suitable I found on research that in 40% of throttle stick, drone start flying. My quad start take off just over neutral point and became hard to control. Can it be a reason of this problem?
-
With props too big, you get too much thrust at low throttle stick and no additional thrust at higher throttle stick. It also makes your motors and ESCs overheat and is less efficient than correct prop size so battery doesn't fly as long and motor/ESC might even fail from too much heat.
What parts do you have available? 8x5 props for these motors or 1000KV motors for the 10x4.5 props?
If you have a prop balancer, you could cut the tips off the 10x4.5 props to make them 8x4.5 (extra wide blade, so maybe even cut to 7.75x4.5 if motors get hot at 8x4.5). I cut 10x4.5 props down to 9x4.5 for one of my quads (F330).
-
Problem solved. Wrong motors and props.
I was using 1400kv motors with 1046 props. I just recognized that the last time I built a quad with CC3D I used 1000kv now I choose 1400kv because It once worked well with QQ super controller. So, Indecided to change my motors. And after that when I tried. It didn’t flew away but don’t stable then. I just import the file that f5soh fixed of my original UAV file. And the quad flew like in the following video file
https://m.youtube.com/watch?v=ICmymmBo34U&feature=youtu.be
Thank You all. Thanks both of you for all of your answers and discussion. It helped a lot and give me a lot of knowledge.