Hello guys,

I am trying to get my Arducopter up in the air, but it seems to get more complex than I thought. 

I followed all the instructions to build and calibrate it as on the google wiki. However I am facing great trouble getting the ESC calibrated. I setup the radio just fine. Then go onto calibrate the ESC and it gives me the first two beeps. Then when I lower the throttle on my radio it does not give me the final beep. My battery is connected and so is the four wire connector to APM. I have a feeling there is something wrong with the ESC. I have been unable to get my motors spinning. Please advise!

Ammar

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There are a lot of steps to go before you will feel comfortable that you have a good research platform, here is a quick list of things you might need to do:

 

* balance the aircraft. Your center of gravity should be as central as you can make it, at least in X and Y. Z, on most AC tends to have a very low center of gravity on most platforms. I have experimented with... well, that is off topic.

* balance the props

* verify ESC to arm mapping. In "+", you need #3 to the front, #4 to the rear, #1 to the starboard/right. 

* verify motor direction, #3 and #4 are CW, #1,#2 are counter clockwise.

* verify correct prop type. #3 and #4 should be marked 10x45R, while the others are just marked 10x45 (no "R") And the markings and textured surface should be up.

NOTE: most people make a mistake in one of the three steps above. Even if they swear they have checked it a dozen times. Even if they are smart CMU students. ;)

* Complete the entire "setup" process after your firmware push, including the "default APM" step. Calibrate the radio, be sure to set either "+" or "X", and be sure it is consistent with your APM mounting. If the APM is fixed with the front between the arms, you have an "X" configuration. Be sure the front left arm is #3 in that configuration. 

* If you built the frame yourself, be sure the APM is mounted correctly. The board will normally be pushed forward and offset slightly, such that more of it resides over the front left arm. Look at the IMU board, and find the X/Y gyro. That is what I use for the center of the board. Yes, it is "off center". I do not think this is all that critical, but I prefer mine to be dead on as much as possible. 

 

After this, and after re-reading the manual, you might be ready for your pre-flight checklist. Lipo batteries are not forgiving, so be sure you know the status of yours. You can burn through a 2200 lipo in about 2 minutes, so don't just assume your lipo is ok. 

 

Now, you should ask yourself... how many spare parts do you have? Because you will need them if you try to just have the ArduCopter pop into the air right now. Before you do that, you should expect to do a hand test.... to try to feel the pull of the motors and see if they seem to be generating thrust in the right directions when you twist the board. I also recommend you tie the aircraft between two chairs, such that you isolate either the X or the Y axis. This will be very helpful for the next step, PID tuning/verification.

 

See http://www.openpilot.org/pid-tuning/ for an example. If you can repeat some of the problem configurations shown in the video, then you will have a much better experience. If you are using the defaults and an official jdrones-style frame/motors/props, then the default PIDs are likely to be good... but if you try to repeat the issues shown in the video, you will learn a lot more. 

 

After that, you should be ok for some untethered tests.... patience pays off.

And stay safe. Keep away from those props. Always disarm. Know your lipos, and respect them. They do catch fire when mistreated and can pose a safety hazard. 

 

I do not think this applies to you, but too many of our current generation of young people have grown up in a bubble wrapped world, with dumb warnings like "Warning, coffee is hot" so they tend to ignore warnings. The current generated by the batteries will kill you. The props will slice your hand open, and you might never play piano again, the batteries will flatten, get ruined, or may spit fire, if mistreated.

 

Oh, and don't forget to have fun :)

 

Thats some really great information. Thanks a lot! I definitely plan on spending quite a while setting up my rotor before getting my actual research underway. Those tips will be very helpful for that. 

As for getting these motors spinning, I tried the calibration steps as you suggested. Though I still didnt get that final 'beep' that I have been craving for. Just assuming for a second that the ESCs are fine and calibrated (even if not thats fine). I tried arming my motors and see the green light ('A') solid. I still do not get a response from my motors. Tomorrow I ll try getting some other spare ESCs from somewhere and try those on. Or it might just be something really small and stupid that I am missing to do..

Radio is working and communicating

ESC four wire connector is on.

All the ESC signal cables are on the power board again. Earlier one of them would be connected the Ch 3 of the Tx.

Lipo is charged and connected.

Bypass the PDB board for the servo/ESC control cables.

 

Plug in the three wire ESC connector directly into the APM:

1) disconnect any props

2) take the servo wire from ESC #1 (right arm) and connect it to the APM, to the right most set of three PINs (looking at the APM from back to front) and white is on the top most pin. Some cables will use orange, red, and black, or orange, red and brown. In any case, it will be black/brown on the bottom, red in the middle, and whatever is left on the top pin. 

Connect it so that the black is at the bottom, and red is in the middle.

3) connect ESC #2, but only connect the white/orange cable. Just flip the cable upside down, and connect only that singular pin at the top. You should have the same color connected to the PIN on APM 1 and 2, and the red and black/brown cable from ESC#2 should just be floating in the air, upside down.

4) do the same for the front arm (#3) and the readr arm (#4)

 

It will look something like this:

                        | | |

                        | | |

. . . . . . . . . . . . | | | |

. . . . . . . . . . . . . . .|

. . . . . . . . . . . . . . .|

 

When you connect the lipo for the first time, leave #4 off. You will hear all four ESCs power on, but then #4 will begin a slow beep, once ever two seconds. This means it has an "irregular signal". Just wanted you to hear it, and know what it means. If your voltage is too low, it will beep once per second. 

 

Too many things can be wrong with the PDB. 

 

One of the reasons for this procedure is so you can see what a proper ESC connection will sound like... it is very easy to flip the servo cables from the ESCs around on the PDB (or for the PDB to be messed up)

 

If your ESCs are not getting a good control signal, they will beep every two seconds. But many, many problems can be side-stepped, for the purpose of learning/testing, by wiring around the PDB...

 

Hope this helps.

Ah, regarding the motors not spinning, did you setup the radio during the setup? Did you assign modes? To spin the motors, you need to arm, and to arm, you need to have your radio set for "stabilize". But for that to happen, your channel 5 signal needs to be set to a PWM value that is configured for stabilize.

 

Power everything on (preferably w/o the props) and in Mission Planner, assuming you are connected to the APM via Mission Planner, select "Configuration-Setup-Modes" The highlighted mode is what your Radio is set for... if it is not stabilize, you might not be able to arm/throttle up. If it is still not working, select configuraiton-setup-radio, and look to see if your throttle bar moves when you provide input...

Hey, Thanks for all the help! I finally managed to get the ESCs calibrated and the motors spinning yesterday. It was a problem with the way I was using the radio set. I had Switch B of my FlySky CT6B radio pulled. This disabled the throttle control. Therefore I saw that the throttle PWM was not changing as I frustratedly moved the toggle. When I pulled down the switch the throttle gave out PWM and everything worked smoothly. 

I am looking through you checklist and manual at the moment and will then attempt to fly it. Thank you so much for the help!

Also, I see that you do aerial imagery. Could you suggest some good telemetry kits (like XBee or 80211) to wirelessly transmit my data to a computer? I will have about 19kbps from my Laser..

And lastly do you know of any good simulators for quadrotors? I coded a basic dynamics model in MATLAB that gives me rotor velocities to follow a certain trajectory, but nothing sophisticated.

You have some sort of LIDAR? Any information you can share about it?

Yea its most likely going to be the Hokuyo URG-04LX

As for motion simulators for quads, I would track down Angela Schöllig, Federico Augugliaro, and Raffaello D’Andrea from the Institute for Dynamic Systems and Control at ETH Zürich in Switzerland. I believe some of them are members here at DIY Drones. If anyone has what you are looking for, I would guess they either know who, or know someone who knows who to ask. 

 

I use Xbee for telemetry. I am expecting delivery of some more xbee hardware any day, but both xbee and non-xbee based 802.11 projects have been discussed here. Review the forum posts in "Wireless" and also search for things like 802.11 across the entire site. There are some other solutions as well, some long range, modest bandwidth radio solutions which are neither xbee nor 802.11. Search for telemetry radio, stuff like that, and you will find it.

ok. I do like their gear, but I haven't been able to find the $1200-8000 to blow on a single sensor. I would maybe spend that on a thermal camera, but not a laser scanner, if I had it. I have been hoping someone would make a breakthrough in a DIY or aftermarket hacked up hardware LIDAR that is light, fast, and not power hungry... and is less than $400. I can hope, right? 

Yes you most certainly can hope for one. I think it should be out fairly soon. I know for a fact Neato uses one, but they just dont sell their range finders. If nothing there will be plenty of stereo camera based depth sensors

 

Confirmed I went back to a older revision(.40) and my ESC's arm properly, using the latest firmware does not arm my ESC's

Help!

 

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