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Since getting video into a computer is cheaper than ever, we've been
contemplating the idea of a cheap, turret mounted camera for position
tracking.  The sonar transducer is a huge source of weight & it doesn't
look like Marcy 1 will ever be stable enough to stay in sonar range.
The reduction in board size & transducer weight would pay off.

The optical mouse is proof that machine vision may replace all other
sensors.  They 1st appeared 25 years ago, requiring grid mousepads.
They barely worked, 10 years ago.  Today, they're taken for granted.

Machine vision would have to difference key out the background.  It
would have to measure X, Y, & Z from a single camera.  It would have to
be cheap enough to justify the means.

After playing around with different color keying algorithms, was pretty
confident position sensing could be done better with vision than sonar &
could be good enough to keep Marcy 1 in a box.  Ideally the camera would
be turret mounted, so that meant recycling a micro camera to build
confidence before investing any money.



This 6 year old laptop camera was never used. 



Really nice LCD, if only we could use it in a new laptop.



Just a standard USB cam.



Reinforced & soldered.

Unfortunately, these old cameras only do 4fps at 640x480.  320x240 in
complete darkness gets them up to 15fps.  The price goes up as frame
rate goes up.  Position sensing is going to be 1Hz, at most.



Finally caved in & got a Logitech C510 camera for only $40, locally.
Turns out the Logitech C510 actually goes up to 1280x1024 even though
it's only advertized at 1280x720.  No surprise why it was for sale &
discontinued.

In bright light, with minimum contrast, minimum brightness, 0
saturation, it'll actually hit 30fps at 1280x1024.  The reality is 15fps
is the most our simplest machine vision algorithm can process.

It spits out tons of bad frames on our desktop, but not on the laptop.
Lacking a way to disable auto exposure is a killer for machine vision.

The object of the game is to detect the center & size of an object.  The
only algorithm that seems to work, at a decent framerate, is luma keying
in a totally black room.  It's certainly good enough, since Marcy 1 can
only fly in total darkness, but developing in total darkness is hard &
we really want to fly other vehicles in daylight.

Flashing LED's would probably work, but Marcy 1 is constantly moving.



Don't turn it on.  Take it a apart.



The stand needs to go.



It definitely has the Auto Pilot look.

Focus is glued in place.





Put it on a pan/tilt platform to try to increase the field of view.  The
problem is it can't use difference keying, the servo movement is going to put a lot of noise

in the result.  A fisheye lens would be ideal.

 

Now we have video of the camera turret tracking the object, & how well
it tracks.  Marcy 1 got a 2nd LED to give the machine vision a bigger
target.  Even though the Logitech C510 can do 1280x1024, we found 640x480 to be

the most useful resolution with the turret. 

Discovered the brightness on the Logitech doesn't buy any more high end.  It
just clamps the white levels at lower values & reduces the size of the
JPG's.  If there was a way to lock the exposure, we'd be ecstatic.

Gigio (udrones) has added a great tutorial to the manual on how to add a pan-tilt camera mount to ArduCopter using Hobbyking parts. Total cost: about $57. Perfect for a GoPro camera.

AC2 defaults to autostabilizing the camera (tilt/roll servo outputs are one Out 5 and Out 6). We'll be adding the ability to automatically track a position on the ground soon.

                    To put everybody in context, this is the very first idea that I had

                    in mind and since picture worth a thousand words,

                    here is the battery exchanger initial concept:

                   Grabber arms, battery casings, electrical connections

                   and some flip-flop action strategy mechanism.

                   Here’s some interesting development aspects in pictures ……….

                   What we are interested in is to have the incoming VTOL precisely

                   positioning itself so that the SWAPPER does its job.

                  The last 10 inches are the most critical for mechanical final touch down alignment.

                  This is the first concept attempt to mechanically guide de VTOL in place.

                    In this case, the legs are guided by the conical receptacles.

                    And then, the concept evolved to this:

                            Earlier initial mechanical contact with the deck increases

                           the correction capacity.

                           The awaiting charged battery is protected from

                           excessive VTOL derivation on the axes.

                          This is the last evolution of the deck concept that I came with

                           The arrow show the derivation slop.

                           In fact this set up permit a YAW mechanical correction of 90 degrees.

                           I’am ending this first development report with what is coming next.

                          Getting some factual datas on this last 10 inches of

                          pre-landing bumping activity.

                         Some pictures of the testing material:

This document describes how to connect an ArduPilotMega with qGroundControl via USB (helpful for first tests of your micro controller).

ArduPilotMega

ArduPilotMega is an Arduino based Autopilot micro controller, programmable with C/C++. Arduino based stuff is nice, because it does not require much of hardware knowledge to get started.

qGroundControl

qGroundControl is is a ground station which can be used to fly a UAV/Drone and it can be used to visualize/test/log data from MAVlink compatible devices (for example the ArduPilotMega).

Preparing the ArduPilotMega

There is not much todo on the hardware side as long as you use the official firmware. At the writing of this post, APM 2.1.2 was the firmware used. It can be "flashed" with the Arduino IDE (using avrdude) or with the APM Mission Planner. You have probably already done this.


Secondly, you need to configure your plane. In my case it's a Multiplex funjet. My configuration looks like this.

APM_Config.h:
// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-// $Id$
#include "funjet.h"


funjet.h:
// $Id$
// NOTE: set dip 4 HIGH (for elevon mix)
//       http://code.google.com/p/ardupilot-mega/wiki/Reversing
//

// DIP Settings for Funjet:
// 1: LOW
// 2: HIGH
// 3: LOW
// 4: HIGH

// Servo channels
// 1: Left Elevon
// 2: Right Elevon
// 3: Throttle
// 4:
// 5: AP Control
// enable HMC5843 - Triple Axis Magnetometer Rev 1.2
#define MAGNETOMETER ENABLED
#define AIRSPEED_SENSOR               ENABLED// #define AIRSPEED_RATIO       1.9936
// ALTITUDE_MIX                             OPTIONAL
// Configures the blend between GPS and pressure altitude.
// 0 = GPS altitude, 1 = Press alt, 0.5 = half and half, etc.
//#define ALTITUDE_MIX       0.5


Once you have compiled and uploaded the code and your configuration you are ready to test sensor data in qGroundControl. Note that no special configuration is needed for the MAVLink protocol on the APM side (as of V 2.1.2) which communicates with qGroundControl.

Make sure that SW2 on the APM is set to flight mode (turned to flight direction) and connect APM via USB cable to your computer.



Flight Mode

You might first test if the APM is sending some binary output over USB. To do this use your favorite terminal program (like hyperterm.exe, minicom or Arduino IDE's Serial Console).

When verified that the binary serial output is sent, start qGroundControl and click on the "Connect Link" Button. The default settings are reasonable, make sure using 115200 baud and select your serial port.

Now change to Engineer's view. You might not get any data yet (left panel with sensor options is empty). In this case APM does not yet know what to transmit. Make sure the «Calibration and Onboard Parameters» widget is shown. Insert 3.3, 10 or 50 Hz in all possible data streams. I read that 50Hz is preferable because the main loop of APM runs on 50Hz. If it causes problems with the serial connection, a lower frequency might help. As soon as these values are set, they are stored in the APM's EEPROM. So these values are present after a reboot of the APM which (I think) is a really nice feature.

That's it, have fun.

Gary Mortimer passes on sad news:

The Washington Post reports the death of Maynard Hill an inspiration to so many in the sUAS world. Our condolences to his family

Maynard Hill, a designer of model airplanes who secured a spot in aviation history in 2003 when one of his creations flew 1,882 miles across the Atlantic Ocean on less than a gallon of fuel, died June 7 of prostate cancer at his home in Silver Spring. He was 85.

A balsa-and-glue virtuoso, Mr. Hill was a legend in the model-aircraft world even before his first-of-its-kind transatlantic feat. Beginning in the 1960s, he set a total of 25 world records for speed, duration and altitude, flying his radio-controlled aircraft as high as 26,990 feet, as long as 38 hours and as fast as 151 miles per hour.

Read the full article here

One of the most commonly-used features in pro UAVs is point-and-click mission control in real time. Rather than just pre-planned missions or manually flying the UAV, operators can just click on a map and say "go here now". 

Good news: we've now implemented this in APM. If you update to the latest Mission Planner and APM code, you can right-click on the map in the GCS and just select "Fly To Here". The UAV will fly there and loiter until you give it another command. We call this "Guided Mode". There are more commands coming in this mode soon, but the functionality is now built-in.

We'll be implementing this in ArduCopter 2 before it comes out of beta, too. Go Guided Mode!

[UPDATE] Team leader Doug Weibel explains how it works:

"Guided is a separate flight mode. If you enter it you will remain in it until you do something to change modes. So if you tell it to "go here now", once it arrives there it will loiter at the Guided waypoint till you tell it to do something else. Something else could either be going to another Guided waypoint (staying in Guided mode) or changing to some other flight mode. If you change to Auto your mission will resume where it left off."

I completed a first test flight for roll stabilization for vertical mapping. It dramatically helps aiming the camera down, and should help with optimizing/maximizing line spacing and acheiving better results for any stitching and photogrammetry processing by getting generally vertical rather than slightly oblique photos.
I used microrax.com for building the mount itself, this is really handy stuff for these types of projects, it is the tiny version of T slot tubing. Once you use it for fabrication of things like these you will not want to use anything else. With the microrax, I can go in with an allen wrench and make easy adjustments to the angles and mount level even installed inside the plane.

I used Alpo's code slightly modified since I could not go full 90 degree stabilization due to the size of the airframe hole and the camera lens. (http://diydrones.com/profiles/blogs/easy-camera-roll-stabilizer-to - thanks for this!)
APM_RC.OutputCh(CH_6, constrain(g.rc_6.radio_in - (dcm.roll_sensor * -0.1),1300,1700));

The flight was not ideal for the test, most of it was turning without much straight and level, but still useful. Their are some jitters and it is by no means smooth, but it does point the camera much more straight down. The hole needs to be widened for vignetting, but this will wait till a final camera is used. Not nearly as nice as the Pteryx design with a rolling section of fuselage for stabilization, but great for a $99 foam airframe.

One of the side reasons for the gel vibration damping was to eliminate any servo noise from the mount stabilization itself, since the vibration damping occurs between the camera and the servo stabilized mount.

What techniques do others use to stabilize for vertical mapping? And if you have suggestions for improving it, please pass them along.

Via Slashdot, here's a story with interesting videos about a group from Boston University.  There's a lot of interesting details about their build and in-the-field fixing.

The Brazilian Free-tailed bats above  (also called Tadarida) come together in the millions in caves all over Texas, leaving every night in swarms so big they can be detected by doppler radar. Somehow, they manage to fly through this dense self-clutter without major collisions, and so our goal is to better understand this behavior. For the AIRFOILS project, the IML team created the previously mentioned Batcopter. The goal was to fly a UAV through the dense clutter, and record the bats’ response with three ground-based high-speed FLIR cameras and an airborne 3D HD GoPro camera. The hope is to extract fundamental control laws of flying behavior in order to achieve better autonomous UAV flight.

 

 

 

I am new to this site within about the last month, trying to get up to speed for aerial mapping using a UAV, currently using ArdupilotMega with a skywalker for vertical mapping. In mounting a small camera inside the fuselage of the Skywalker, I experimented with silicon gel for vibration isolation, which appears to be promising. The current testing used a Canon SD1200 IS camera because it was available, but I would plan on using something with a larger imaging sensor in the future (http://www.rcgroups.com/forums/showthread.php?t=1351104).

The test flight in the video above used the SD1200 in video mode in order to collect a continuous record of vibration and performance, stabilization was turned off for the flight.

I am now starting on roll stabilization using Alpo's code technique. I also need to solve camera triggering, hoping that an IR trigger solution will work. Since I may move to a Sony Nex-5, I need a non CHDK canon option for triggering.
The silicon gel approach looks very effective so far, in the future I will order some gel tape with adhesive backing for a more integrated solution and to adhere the camera to the mount, somewhat like double sided foam tape, except gel. The gel is very effective for high frequency vibration if the surface area used is matched well with the weight of the object. Their may be issues with lower frequency vibration, but that is likely the case with almost any design. Any suggestions, advice, and observations are appreciated.

I really enjoy making FPV videos. But recently we started producing and selling our aircraft to customers around the world, which has taken up so much time it's hard for us to produce enough videos to fit our weekly schedule. So it's very refreshing to see that at least our customers are having fun :) These are a couple of clips from two of our first customers doing their first ever FPV flights (zero prior FPV experience!). Enjoy!

Hi all,

in the subject of mapping from the air, it is important to know how many pixels fall per cm on the ground.

Following

http://en.wikipedia.org/wiki/Angle_of_view

we got the following angles of view from equivalent focal length and we can compute aspect ratio from them:

On the other hand you have sensor resolution:

Canon S90 is  3648 x 2736 = 9980928 roughly 10MPIX

this is aspect ratio 3648/2736=1.333...

It is said to be equivalent to focal length 28...105mm.

On the other hand all aspect ratios calculated above are well above 1.33.

Conclusion: even standard lens are generating wider view than the sensor is,

resulting in less horisontal than vertical resolution.

True or false?

6x 10 grak motor+6 amp esc.

openpilot brain.

800mah lipo.

10 cm props.

235 gram in the air.

i stil need to do pid tunig its not stabel jet.

hope you like it.

Hello all,

After some field testing, i'm finally ready to release a copy of the Android based, bluetooth GCS for ArduCopter into the wild.

For all the details go to the site.

Its available in 3 ways:

• Install from Android Market ($5, largely to offset publishing costs/support development) Copter-GCS
• Install the APK from the download section (Free)
• Build from source, following these instuctions.

The reason for the market version is for those who would like to just install in the easiest way possible / receive automatic updates or would like to support development costs (thanks you) such as the fee required to publish on the market.

Current features:

• GPS plotting of phone and GPS, quad path rendering and logging of the track to the SD card.
• Sensor graphing
• Status display, such as current mode and GPS state
• Setup
  • PID Tuning
  • Accelerometer Offsets, both traditional and using the drift direction
  • Transmitter Calibration

Let me know how it works for those that try :)

Bart.

From the Parrot AR.Drone Twitter feed:

#E3 new automatic pilot demo today: come & watch 4 Parrot AR.Drone synchronized dancing! Booth 835 south hall.

I'm sorry to keep posting stats on our growth here, but this is my baby and I can't help but be a little proud. We're now doing more than 1 million page views a month! Nice page/visit ratio, too.

This new OSD was listed on the Hobbyking website today. The HobbyKing G-OSD unit is a quick and easy way to add GPS on screen information to your FPV system. With GPS Coordinates, airspeed, voltmeter and many more display functions this OSD unit will make a great addition to any FPV setup at a fraction of the cost of other GPS OSD systems currently available.

Features:
GPS coordinate display, time display, airspeed display
voltmeter and stopwatch
RSSI receiver signal strength detection
Programmable display content
Supports NTSC and PAL TV signal
Supports anti-glare shade control signal
Supports manual calibration

Specifications:
Weight: main board 4.6g / GPS module 22g
Size: main board 34mmx20mmx4mm / GPS Module 35mmx35mmx5mm
Working Voltage: G-OSD 7.4V-12V / GPS Module 5V

Price is US$ 37.51 (depending on you Hobbyking membership level, it can be lower). More information on the product page

After being stuck dead in the water for 6 wks waiting for a new Tx.... Today was the day to do some real testing.  The weather was almost perfect, little gusty but not to bad.  I did some rough PID tuning in the garage late last night, and soldered the 3 Gyro pads.  It still wants to drift and the YAW might just need some PID-Tuning to get it acting right.  The front Left motor with all the vibration must be replaced.  I can really tell in the video that the copter is fighting with it as well as the gustyness and the YAW + Drift.  Right before the Crash I had almost full forward stick but nothing was happening.  Then soon as I let off the stick it freaked out.  The Quad frame worked out as intended. Protected the electronics from hard landing / crash.  I would rather destroy the chassi than the electronic's.  So now time for new motors, and a stronger frame. 

How to Chat on DIY-Drones.

1.)  Click on " My Page"

2.)  look @ Bottom right corner of the screen.  Kinda works like FaceBook Chat.

Every day I find fellow DIY-Droners that have no clue that there is live " Chat "  they can use to help others or get help from others.

Happy Chatting