An oscilloscope turned out to be a pretty handy debugging tool when trying to troubleshoot my APM2 ESC problem. Here's a shakycam showing how I used mine to verify the problem was with the ESC and not with the APM2.
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I got everything together last night and couldn't wait until the morning to go out, so I took a quick flight in the basement. Stability was pretty good. I made a quick video of simple mode too.
Both Andreas and I had the same problem... fortunately he had it before I did, and had figured out a workaround.
Problem: when powering up, not all motors will spin.
Workaround: apply power to the APM2 before attaching the main battery. You can do this either via USB or by attaching a spare battery/ESC to one of the output lines. As soon as the board boots up, hook up the main battery and remove the second battery.
This is my second flight with the GU-INS in GPS Hold mode
Standard setup
ArduCopter in action: Testing the QuadCopter (HIL mode) on X-Plane v9
Here a video a the ArduMega board (2560 or 1280) with the firmware ArduCopter v2.1.1b (JLN update for X-Plane) connected on the X-Plane simulator throught the APM Planner in HIL mode. The QuadCopter QRO has been modelized for X-Plane v9.0 (or greater) so as get a closest replication of a true QuadCopter UAV.
This is a very good method for testing all the features of the ArduCopter firmware. For conducting a such test, only an ArduMega board (APM1280, APM2560, APM2) is used, no IMU shield or sensor are required here...
Setup:
- Receiver: Turnigy 9X8C v2 connected to the APM board
- Transmitter: Turnigy 9x
- APM planner v1.1.1x
- ArduMega board (APM v1 or APM v2)
- firmware ArduCopter v2.x.x + the JLN mod for X-Plane
- Software: X-Plane v9 or greater
- QRO_X: the quadcopter model (by JLN) for X-Plane
More infos at:
An interesting discussion of the risks and benefits of automation for air and other forms travel.
Click the link below to go to the webpage and listen:
http://spectrum.ieee.org/podcast/aerospace/aviation/the-benefits-of-risk
Quad-copter equipped with the advanced AS3X by Blade (Horizon Hobby)
Ahhh the holidays.
I'd never have the time for an indulgence like this little project any other time of year.
At least not at the rate it's progressing. So far I've managed to get everything that I have assembled into what looks like a nearly complete Tricopter. I really like the double clam shell center that my old tape cartridge boxes make. Everything flips open easily for access to components. They're not airtight, so the barometer shouldn't have any problem. They're clear, so I can easily see the rat's nest of wires, and also all the LEDs happily blinking to tell me everything's ok. At least, one hopes that what they're blinking...
I still need to figure out landing gear. There's dozens of options, but first off I'm going to work out how I want to mount the battery so as to get it just forward enough to balance the weight of the yaw platform in the rear.
For landing gear, I'm thinking a piece of wire coat hanger bend in a D shape and zip tied in place on each arm. It's flexible, and my hope is that the tie wraps should allow for enough movement to absorb any less than gentle landings without passing the shock along to the arms.
I measured a few things earlier and found out that my shaft to shaft distance isn't quite as symmetrical as I'd like. Somehow I've ended up with 51cm across the front, 51.2 from right to rear and 50 from left to rear. Hopefully in tuning I'll be able to work it all out so that it can still fly. Though... now that I sit here staring at it, setting the yaw with just a little tilt to the right, which it will need to counter the yaw from the 3rd prop, I get a nice even measurement of 51cm all around.
Not bad for some basement work on the old kitchen table using nothing more than hand tools!
Missing bits still include my prop adapters, one reverse prop and a battery connector. I could run off and get them locally, but I've already ordered them online. In the spirit once again, of QSC (quick, simple, cheap) I'll hold off and wait for them to arrive.
On the copter itself, I've spent:
$18 on some 3/8" basswood for the arms and some 1/16" sheets for the center. I still have enough to make a whole other copter, or use as spares when the ground interrupts my fun, because it's always the ground's fault... right?
$130 with shipping, on 4 motors(1 spare), 4 ESCs (again, a spare), a receiver, 2 servos (you guessed it, another spare), and random supplies like nylon bolts, zip ties, connectors, servo leads, and props.
$260 with shipping, on an APM2 and a few other bits from 3DR. For now my APM 1280 is in there just to get some things worked out.
So, including some spare parts, a total of $408, INCLUDING shipping. Add maybe another $10 of stuff I already had on hand like ball links, some threaded rod, loctite, velcro and shrink tubing.
I invested a little also, picking up a dremel workstation/drill press and a new soldering gun, because as I found out, my little 25 watt gun just couldn't get hot enough to heat 2 pieces of 16ga wire and flow the solder between them. Oh, incidentally, the ability to effortlessly drill perpendicular holes in narrow bits of wood is akin to a superpower.
I can't wait to see if this thing is in any way stable in the air!
Very interesting video from VectorNav showing what high frequency noise and magnetic fields actually do to an imu.
Nice visual representation!
Also this vectornav unit seems to be quite the imu!
G:)
Another good article from IEEE Spectrum. I'm particularly interested in the disposable glider drone at the bottom, which is basically just a PCB with wings. (Because this comes from the research arm of the Navy, and is of broad technical interest to this community, I am make a sysadmin exemption to our no-military rule. I don't do it often.)
Excerpt:
Here's a wild way to launch UAVs: by using a high-altitude weather balloon with a drone stapled to it, with drones stapled to it. Nope, that's not a typo: The Naval Research Laboratory has been using weather balloons to carry a medium-sized Tempest UAV up to 60,000 feet, and the Tempest UAV itself is carrying a pair of tiny little CICADA (Close-In Covert Autonomous Disposable Aircraft ) drones underneath its wings. Look:
The Tempest can travel up to 30 miles and deploy the CICADAs as gliders, which can then land within 15 feet of their target coordinates. Each CICADA can carry a variety of sensor payloads, and as the name implies, they're designed to be cheap and disposable: The airframe is actually just a custom printed circuit board.
This balloon launch multi-drone thing in particular is very cool, since whatever you attach to the balloon can use its engine purely for range as opposed to altitude. And dropping off these little microdrones to get in and do the dirty work saves a bunch of money and adds that much more versatility to the entire system.
A video of one of my test flights, pushing it hard.
Finally got the time to finish my quad and (attempt to) fly it! It's my first quad. and I went a little different with the setup (see specs below) to try and see if I could push the propulsive efficiency up a bit and have more power on tap for heavier payloads down the line. My static tests indicated that this is the case, but we'll see if it was worth the effort after some more flying :)
Setup:
APM 2.0
3DR Frame
DT750kv motors
Turnigy 25amp Plush ESCs
12x3.8 SF APC props
Turnigy 4000mah 3s 30-40c
Hitec Aurora 9
TOGW = 1420 grams
See current tuning:
Video of best flight (i.e. didn't flip over or hit a tree)
Positives:
1) It flew!
2) Somewhat stable..
3) No damage besides mostly superficial prop scuffing and small chip at one prop tip. 3DR frame seems pretty darn solid. I tried to take it easy
Issues:
1) Even though i triple checked the wiring (albeit, I did not do the complete pre-flight check.. shame on me) I seem to have motors reversed. It rolls the way I expect it to - Left stick = left, right stick = right; but it pitches opposite - Fwd stick = reverse flight, Backwards stick = forward flight. Can this simply be fixed by reversing my throttle command on my transmitter? My first though it that this will work with the stablized mode, but any other mode will not be corrected. Or is this the standard way to fly a quad?
Note: just checked PBD wiring again and it's correct according to these instructions. Still not sure why it pitches opposite of what i am expecting.
2) As you can see in the videos the quad tends to drift (all of my flying was done in "stable mode") in various directions. I also see some oscillations. Tuning advice?
3) On a few occasions after a hard landing, the quad would flip it's and max throttle the motors attempting to right itself for a few seconds (hence the prop scuffing). Is this common? Gentler landings did not seem to cause this problem.
One note: besides some R/C planes and one of those small, stabilized RC helis I have not flown anything like this. I am sure that some of the issues are pilot error which will only improve with more time.
I am going to attempt to fly it again tomorrow, but will probably try to find a bigger area.. with grass.
Thanks!
Jonathan
Great list of trends to watch in 2012 from Make Magazine. The full list:
- Drone Journalism
- Wearables
- 3D Printing
- Internet of Things
- Arduino hits 1 million units
- World "Kinect'd"
- Crowdfunding
- Libraries becoming hackerspaces
These flying thresher designs show up every now and then. They supposedly have some sort of aerodynamic advantages, but it's not clear what they are since they never seem to make it out of the lab. Here's the latest, from the University of Maryland.
From the video description:
Cyclocopter utilizes cycloidal-rotors (cyclorotors), a revolutionary horizontal axis propulsion concept which has many advantages such as higher aerodynamic efficiency and maneuverability. One of the key advantages of the cyclorotor is its thrust vectoring capability, which is utilized in the present study for yaw control. The present vehicle has a twin-cyclorotor and a horizontal tail rotor configuration where each of the rotors is powered using independent motors.
The cyclorotor design was optimized based on the detailed experimental studies conducted by Dr. Moble Benedict, Mr. Tejaswi Jarugumilli and Prof. Inderjit Chopra. A novel attitude control technique is developed using differential RPM control and thrust vectoring of the cyclorotors for rolling and yawing, and horizontal tail rotor for pitch control. For closed-loop attitude stabilization of the vehicle, a proportional-derivative controller was implemented on an onboard 1.5 gram processor-sensor board. Using this control system, the stable autonomous hover of the cyclocopter was successfully demonstrated.
Inspired by avh's Thingverse 3D files for a replacement ArduCopter frame (shown above), the MakerBot blog has offered a challenge:
9000 internet points and bragging rights to the person who can get me an on-board flight video from any kind of ‘copter sporting any number of printed parts.
I'm not sure what the current conversion rate is between internet points and dollars, but this is worth doing for the bragging rights alone.
I’ve been wondering, what would be the easiest way to route telemetry and commands from APM to Internet. Using 3G modem, would provide almost unlimited range (I know there has been some discussions about this in DiyDrones forum. Here in Finland the GSM network is very covering, but due the way the cellular towers are optimized, maximum altitude where the connection works is probably less than 200 m.)
In theory, list of required hardware is not long. One just needs to receive messages from APM and encapsulate them to UDP packets and send via 3G modem and vice versa. Unfortunately handling PPP communications is too large task for simple microcontrollers. I ended up using BeagleBoard for the sake of easy development and since I had one at hand. I realize that BeagleBoard (which essentially is full computer by itself) is an overkill, but it’s not very heavy and fits easily inside Maja’s fuselage. Basically any embedded system, capable of running linux and acting as an usb host would do. Maybe in the future I figure out some additional tasks for BeagleBoard to do.
The setup works quite nice now. Unfortunately I haven't been able to do much flight testing. Weather constantly sucks this winter here in Finland. As you can see I already installed skis, but there's not even snow, even though it's almost new year.
I wrote more detailed post to my blog, with link to sources: http://antibore.wordpress.com/2011/12/28/routing-apm-communications-to-internet/
Yesterday we scanned an area of around 2 million square meters and made an Ortophoto model with DEM 3d output. The flight was 15 min long. As you can see from the 3d model we scanned an area with diverse terrain. What is fascinating here is that the altitude error is less than 0.5m. From these models we can calculate yearly wood volume changes, we do landslide analysis, do research for flooding areas and more unlimited options.
Helicopters, HTML & democracy: be a HACKER-JOURNALIST
Making software in the newsroom is the best job I’ve ever had.
It’s great work, and it’s for a purpose. We’re not here to “save journalism” (whatever that means) — we’re here to save democracy.
Requirements
- A passion for the news
- Serious programming skills
- An understanding of the inner workings of the web
- Attention to detail and love for making things
- A genuine and friendly disposition
On any given day you might implement a responsive web design w/ HTML5 + CSS3, explore a dataset with a reporter looking over your shoulder, or help invent new ways to report the news.
Bonus points for…
- Experience flying quad-rotor helicopters or mapping balloons
- Information / graphic design
- User experience / usability / empathy
Enter shameless link to sUAS News here
Another Christmas/New Year's video. Enjoy!
This one was made using something like puppetry: an "actor" would hold a quadrocopter (props off) and move it. The motion would be reflected by another (flying) quadrocopter -- so you can do fun things like try to express emotions, walk around with some sort of a gait, look at things, etc.
Happy Holidays!
