Blogs

Starting at about 2:46 in this NASA video, a rocket powered quad with payload!

Mars Science Laboratory (Curiosity Rover) Mission Animation

ITU Tilt-Rotor VTOL UAV concept from here

A good mate and I were talking a few weeks ago about the AR Drone and it's possible application in scouting for our hunting trips. We discussed putting bigger batteries in it and using a directional antenna to increase it's range and flight time but we came across several problems, the first being the fact that by the time we unpacked it and flew it out to it's maximum range, one of us could have just walked over and taken a look for ourselves.

This prompted a discussion on what our actual requirements were and after seeing a few youtube clips of aggressive maneuvering by quadrotors, we decided to build. My mate has an electronics background and mine is IT so we figured we'd be able to work the project ourselves. I fly micro helicopters as well as R/C planes and have built several from scratch.

Our requirements are these:

1. Man Portable
2. VTOL
3. Autonomous flight via waypoints
4. Ability to loiter
5. Video Feed

So from here... the Planning begins.

One of the best decisions we made was basing our autopilot system on Arduino (credit goes to Jordi for spotting its potential so early and selling me on it). The engineers all sniffed at it, complaining that it was just an 8-bit processor running at 16Mhz and could never compete with 32-bit ARM processors running at 70Mhz and faster. But what Jordi spotted was something more: the Atmel chips are RISC processors and very effecient, an autopilot is not actually a very computationally intensive task, and most importantly, it's not about "feeds and speeds", it's about community, which Arduino attracts by being cheap, open and very easy to use.

Arduino has won the community competition hands down. The chart above is from the latest status post, and it shows more than 750,000 monthly vistors to the website and nearly 5 million monthly page views. These figures continue to grow at 100% per year.

Community brings tens of thousands of smart people around a platform, and many hands make light work. The amount of code and libraries out there that can be used for free are staggering and there's little need to reinvent the wheel. What basing the ArduPilot line on Arduino has meant is that we're not just using a great technology platform; we're part of a movement. That means not just great tools and thousands of available developers, but also a "cool factor", that really helps with marketing and adoption. In short, the success of the Arduino revolution is thrilling to watch, not least because it means we've hitched our wagon to the right horse!

Whilst those of you in the USA await regulation to allow flight, other countries are pushing forward.

Project URSULA (UAS Remote Sensing for Use in Land Applications) was launched by Welsh Assembly Minister for Rural Affairs, Elin Jones. The 2 year research and development programme will explore the potential for advanced remote sensing, using small unmanned aircraft, for use in land applications, primarily high input arable farming. The project is supported by the Welsh Assembly Government.

About autonomy this is ..... WOW ! 

From the Economist (jan-11)  http://www.economist.com/node/17951584

Fantastic project, which was 3D printed at Shapeways. Here's their blog post describing the whole thing. Check out the lovely snap fit with a twist-knob closure design.

Video of the week. Hands down.

Hi,

trying to help a developer (Ben Levitt) to track down a bug on my UavDevBoard system, it was hard to explain by email the strange behavior.

After he suggested me to try with a sound card oscilloscope, I decided to try something I was planning from sometime now : a soundcard oscilloscope.

I build a voltage divider to scale down PWM voltage (3.3V) to about 0.7V, which is more suitable for a PC audio input.

I crimped a couple of cables with servo connectors on one side and a stereo mini jack, from a boken headphone on the other side.

The interface is double channel capable, but some PC (like my laptop) only has mono input.

On the picture above you can see a double channel PWM signal from two different UavDevBoard outputs.

As soundcard oscilloscope I use Zelscope, which is ridiculously cheap, and Visual Analyser, which is free instead.

Here you can find a little tutorial, with schematics and pictures, I did about all that.

Best regards,

Ric

Hello,

here is the last news of my development.

I received my small 5dof imu, some new sample of the last 24bits integrated pressure sensor from intersema MS5706, I plug everything on my RC receiver and telemetry transmitter and look at what will work... Surprisingly .. everything...

I check the range out of my telemetry board with just a crap antenna, and it is far from being good, less than 100m...

waiting for other antenna to make other check, I must have mistaken something...

beside that I bought one of those ultra-cheap android tablet and started to look what can be done and how...

there is only a dirty wifi module, no bluetooth, a crapy 30pin ipod style dongle that give 2 usb port, 1 rs232 plugged to u-boot and a rj45.

So I plugged one of my board on it and try some things...

I First had some bad luck, the software is fully buggy, the tablet is ultra slow, impossible to root it so it is impossible to access the serial port (for writting), but I succesfully was able to read the serial data that come out of my board via USB CDC bridge.

I'm not good either with java, and the emulator works worth than the real tablet... but I did some stuff that seems to work ;)

... to be continued... (I'm waiting for stuffs...)

Got some high speed photographs of Marcy 1 spinning at flight speed, to see if the actuator & the wing did anything.   A slow motion video cam would be nice.

The idea was to make a wing which would be pressed up into an actuator
by the airflow, but there was no way to see if it was pressing up
without high speed photography.  It definitely converges on a natural
angle at which She takes off.  The actuator needs to go slightly steeper
than that, to accommodate water loads.  Maybe the hinge tape was keeping
it from pressing up.

It was less like hinge tape & more like kite string.  The wing was
free hanging off the spar & still lifting the fuselage. There was an
oscillation in the wing angle. 

Next, came a paraglider concept, with extreme turbulance.  There is a
limit to the hang distance.  The free hanging wing solved a lot of
problems, regardless of its actuateability.  Its own weight turns it
into an airfoil.

Finally arrived at a wing with actuator, where the air flow was enough to restore its angle.

Finally, the wing actuator came on, the wing moved slightly, & nothing happened.  There was no rolling, no lift, no nothing.

Another control surface behind the propeller didn't have enough thrust to overcome the airflow, at all. 

It's getting closer to a heavy, brushed servo.  How about a home made LCD driver, instead.  A way to display data for $1 would be real useful for the credit challenged.

Took interest in using these $1 LCD panels to display data.

They have 4 ground planes, connected to all segments, & 10 wires connected to half of each digit.  They're wired in such a way that any single segment can be lit by a combination of ground plane & half digit.

Driving LCD panels with bare voltages is a bit harder than sending commands to a UART.  We reverse engineered the waveform, since The Goog had nothing on it.

The easiest route for us was using a voltage divider to get 1.5V & making the planes 0V or 3.3V for on & 1.5V for off.

The panel could actually be driven with only 0V & 3.3V, but it wouldn't work in sunlight.  Either the UV light or the heat turns on all the segments.  This alternating current with 3 voltages is how all passive matrix LCD panels work, but everything from the earliest 1970's watch to the newest LED backlit phone uses alternating current in some form.

Just saw this on Reddit, thought others would find the AP work interesting:

http://cryptome.org/eyeball/daiichi-npp/daiichi-photos.htm

New long range module for Turnigy 9X 9Ch Transmitter or other JR Radios.

Long range JR UHF radio system 265 USD

The new UHF RC system is based on Ham band and neighbouring band from 400mhz-470mhz, with the frequency hopping technology and frequency sweeping technology, you never need to worry about losing control of your precious plane.

Have short range trouble? this LRS has a range beyond your imagination. with a bad antenna, you may still get 20km range in the air, and with a super good 1/2 wave length one, you can even get 60km in the air.

Parameters:

RF output:1000mw-2200mw

Power comsumption: 300-600mA 

Range: 20-60km in the air

Failsafe: Yes

High and low power selection: 1000mw or 2000mw output

Highspeed control: yes

Transmitter parameters:

Hardware frequency Range 400MHz to 470MHz
Frequency stability :2.5ppm
Output low-pass Filter :NONE

Band 1
Start frequency:415Mhz
Step frequency:480Khz
Channel :70

Band 2
Start frequency:433Mhz
Step frequency:30Khz
Channel :70

Output Power : 30DB Peak / 33DB Peak

Rate : 40Hz/66Hz

RF interface impedance :50 Ohm

Supply Voltage :  8.4V to 16V
Reverse battery protection:NONE

Logic Voltage :3-12V

Current :
330mA/520mA (@50 Ohm load,12V Supply Voltage)
250mA/440mA (@No-load,12V Supply Voltage)
950mA/1.6A (@RF Short circuit,12V Supply Voltage)

Temperature:50 to 70 Degrees Celsius

Receiver parameter:

Frequency Range 400MHz to 470MHz

Sensitivity :     -112 DBM @0.1EBR(40Hz Refresh rate)
                  -111 DBM @0.1EBR(50Hz Refresh rate)
                  -110 DBM @0.1EBR(66Hz Refresh rate)
                  -108 DBM @0.1EBR(90Hz Refresh rate)
                  -104 DBM @0.1EBR(125Hz Refresh rate)
                  -104 DBM @0.1EBR(166Hz Refresh rate)
                  -101 DBM @0.1EBR(250Hz Refresh rate)

F/S turn on condition : >0.99EBR

Antenna gain : 2.15DBM

Step frequency :10kHz

Bandpass filter:Chip integration
Out-of-band rejection  :No specific data
It can work with video and audio transmitter which frequency less than 300Mhz or higher than 500Mhz .

Refresh rate :40Hz50Hz66Hz90Hz125Hz166Hz250Hz

Hopping rate :40Hz50Hz66Hz90Hz125Hz166Hz250Hz

Hopping cycle:13Hz16Hz22Hz30Hz41Hz 55Hz 83Hz

Recover time :77mS62mS45mS33mS24mS 18mS 12mS
        
Response Time : 4mS to 25mS

PWM Output accuracy :0.5uS step ERROR<20PPM

PWM Output range : 0.5mS-2.5mS

PWM output cycle :55Hz  @Normal mode
                  192Hz @Fast mode

PPM Output accuracy :0.5uS step ERROR<20PPM

PPM Output range : 0.5mS-2.5mS Each channel

PPM output cycle :50Hz@Normal mode & 1mS to 2mS Output
                   42Hz to 50Hz  @Normal mode & 0.5mS to 2.5mS Output
                         50Hz to 83Hz  @Fast mode   & 1mS to 2mS Output
                        42Hz to 125Hz @Fast mode   & 0.5mS to 2.5mS Output

PPM sync pulse width:4mS to 16mS  Automatic adjust @Normal mode
                     4mS Locked                    @Fast mode

Recommend Supply Voltage :    3V to 8.4V

Shutdown voltage :2.1(+-0.15)V

Damage voltage   :>15V

Power supply noise cancellation  :<=15 VPP

Reverse breakdown voltage : >-15V

Output ports withstand voltage : >12V

Normal Current : <110mA

Operating Temperature :–40 to +80 °C

Also available as a UHF Futaba module

well, that's an annoying thing to do ...!

But definitely rewarding.

My test bench was actually the arducopter arm, on which i mounted the prop to be balanced.

i hesitated how to balance them, as ordering a balancer now and waiting for it to arrive for a month would piss me off....

as i tried to run an un-balanced prop, the vibration were so noticeable that i decided to test it on the frame itself.

the before and after difference is HUGE.

and finally this is the testing setup:

Hi all,
My MAP-One is finally ready!
Remember, this is an autopilot based on pic18f452, but I do an error, it doesn't work at 40Mhz but just at 20Mhz because I choose a 20Mz crystal...stupid.

It can control 4 servos and esc, it can receive 4 rc signal from rc receiver. This autopilot is development platform for my gyro and accelerometer. This is not really an autopilot because it doesn't possess GPS or magnetometer. It has a on-board pressure sensor, xbee (or serial) connector, and other connectors for analog sensors.
The pressure sensor is missing, but my board works well !
I test the serial (with ftdi adapter) and the ADC,I transmit value at 9600 bauds. Today I test servo and that works !

This my first board and my first autopilot (stabilization system) project. Be forgiving ;)

http://mapdrone.wordpress.com/about/map-one/

Dear Friends ,

the 07/04 will doing a online webcast where we present last updates of Multipilot32 project.

The index of presentation are :

• Improvment of IDE and library , new functionality and new lib , i2c lib is available and work !! , now we support all standard diydrones accessories:).
• Ready to use bin Example for testing your MP32  : Introduce Sensor Lab.
• Pre Flight Check with Arducopter NG 32 and Multipilot 32.
• Introduce new release of IMU and a RTF concept board.

Standard Fly configuration :

This is the official link to join the event:

http://www.virtualrobotix.com/events/webcast-on-multipilot32

We're back in stock , so the board is available.

Link of offcial product page :

http://www.virtualrobotix.com/page/multipilot32-1

First Flight video with Arducopter NG 32 on ArmFox V.4.

Main Thread :

Status of the project you can found daily update :

http://www.virtualrobotix.com/forum/topics/multipilot32-vride-and-vros

Power Point Presentation of Official Multipilot32 presentation.

http://www.virtualrobotix.com/profiles/blogs/multipilot-32-power-point

Getting started usefull information about the board , tools ,libary and firmware available for developing code on Multipilot32

http://www.virtualrobotix.com/forum/topics/multipilot32-getting-started

As you've all probably read in Chris' posts, DIY Drones/3D Robotics is growing fast. We're now at the point where we need to hire a full time Web Developer/Software Engineer to support the current website and upgrade the store to a better architecture as well as programming in Arduino to support new hardware development. Ideally, we would like someone who is as passionate about UAVs as we are, so we're turning to the community for the right person! If you have the skills listed below (or know someone that does), we want to hear from you! Competitive salary.

Desired skills:

-HTML, XHTML, HTML5, Java Script, SQL, PHP, AJAX.
-Some experience in databases.
-Experience with Zen Cart.
-Basic designer skill's and CSS.
-Networking and servers.
-Linux, Windows and Mac.
-Some Photoshop and photography (preferred).

Other skills in addition to the above:

- Strong teamwork and cooperative design skills.
- Self-motivated to learn and solve problems independently.
- RC/full-scale airplane or helicopter experience.
- C/C++ Programming and Arduino IDE...
- Strong technical writing skills preferred.
- Living near San Diego, CA or willing to relocate

For those of you who don't know me, I'm the newest addition to the 3d robotics team. I'm here to help get more new products into your hands faster. I can personally attest to the fun and exciting work environment at DIY Drones headquarters. Please forward your resumes to ardupilot@gmail.com and don't hesitate to contact me personally if you have any questions. We look forward to hearing from you!

My ArduPilot Trials Day 2

I started off the day very excited to see how a new day of testing would go. I'd re-read portions of the manual, searched for ArduPilot tuning posts and contemplated the replies I got from my previous post.

The conditions were great and I was ready to toss that sucker up and get some satisfaction.
Instead, I learned a lesson. You see the picture above? That's what you get when you fly your plane using the wrong configuration on your radio. Notice how the tall grass beacons my plane to follow it's shadow... Well it did! Fortunately for me the grass was tall and I was quickly able to see the problem and cut power so no damage to speak of.

After I double-checked the electronics and hardware I reset the model in the radio to the appropriate configuration I got a GPS lock and tossed it up. I waited to engage the ArduPilot, which was in Stabilize mode until I trimmed out the model. Wow, what a great flight. The Stabilize mode checked out wonderfully. My fellow flyers were impressed with how well it did, especially when I used the stabilizer to bring it in for a landing. It was truly great. I lined it up on the approach I wanted, into a slight breeze and cut the gas and it glided in perfectly.

My ArduPilot Trials Day 3
Like yesterday I started of today very excited to try the next test. After flying yesterday, I took home the plane so I could change it's mode from Stabilize to Fly-By-Wire-A.

I was all set and ready to figure out what the heck "tell it where you want to go and it'll figure it out" was all about (that's a slight synopsis of the description of the FBW modes). I got my lock, put the wing on and gave it a toss.

Again, I learned a lesson. Not a new lesson, but one that should have been very fresh in my mind. You see the pictures below? That's what you get when you fly your plane using the wrong configuration on your radio. Notice how the tall grass beacons my plane to follow it's shadow... This time the grass was shorter and right next to a service road! Fortunately for me it was the grass, which was tall enough so again damage to speak of, just a bruised ego as I had watchers and needed a rubber band to hold on the GPS which had popped off.

So just what was that lesson? No it's not "dont fly your stryker" or even "double-check your model". It's Use Checklists to avoid these type of problems. I could have been sent back to ground zero with either of these crashes. I'm now building some easy grease pencil checklists that I'm going to attach to the plane and complete right on the model prior to flight. That should save me from myself and from having to remember to bring the list!

Todays second attempt went very well. Again once I trimmed out and got the model into the AP mode the FBW worked very well. It is different than the Co-Pilot for sure, but I use the rudder to produce a flat turn. The flatter the turn the better it's keeping itself stable. I did not get the chance to do the tests that are recommended for FBW, that will be next flight. For now I'm very happy with the ArduPilot. I again used the AP to land the plane, which was a little off from yesterdays great landing but I blame that more on me and how nervous I was after drilling the plane into the ground two days in a row. It did remain very stable during the approach and landing the line up was a little off so I had to walk a few yards to retrieve it instead of a few feet like the previous day. No big deal.

Next Test, FlyByWire-B, although I'm not sure what to expect in this mode with the motor? I guess it just keeps it constant? If anyone can explain that I'd appreciate it.

Wish me luck!

Notice how it's not quite square to the frame of the first picture? That creates visual interest!

In the second shot the shadow almost forces your eye to whats outside of the frame.

The third shot conveys movement. Notice how the grass in the background is in focus yet the foreground grass is blurred as the plane smashes into it...
Last but not least a nice shot after the model was corrected.