Because the latter one of condor drone tests went very well in the navigation, I decided to mount the camera aboard the condor photography for mapping and the results appear promising.
Several months ago I started working on a system called Afterflight to organize and browse my tlogs and dataflash logs, sync them with video, and view them along with a map GPS display. It still has a long way to go, but there is a fair amount of working functionality so I figured I'd get it out there for comment, warts and all. I would love to see it flourish as a collaborative project with lots of committers, see it get merged into another project, or whatever is most useful for the community. If anyone is interested in providing funding for it (or hiring me!) I'd love to hear that, as well, since I am a "starving PhD student". Alternatively there is a donate link if you click "about" in the software.
The source code has been available under the Apache License at http://afterflight.googlecode.com since I first started work on the project. I have an example server running at http://afterflight.volcanocopter.com
If you want a quick demonstration of what it can do, click on the first log entry, which will take you here . Press play on the video and you should see the map, graphs, and timeline animate.
Here's how it works at the moment:
Improvements I'd like to make in the future:
I'm not the only one who had realized the power of the browser as a component of an Unmanned Aerial System. These are the other browser-based projects I'm aware of:
Hope you find this useful!
Cheers,
Aaron (foobarbecue)
Here's an excerpt:
...
...
http://whatsnext.blogs.cnn.com/2013/05/23/drones-the-future-of-disaster-response/?hpt=hp_bn5
I had a couple of requests for a still shot of the 12-rotor beast that Joe and Justin cooked up, so here it is.
This might be a common knowledge, but in the last months I haven't seen a similar post. Maybe someone new to barometers might be interested in this data.
The GPS receivers return altitude data, but this is inaccurate. The error margin depends on the satellite constellation geometry and whether or not you have SBAS DGPS on. I was under the impression that the error was 5-10 meters, but as it turned out, I was wrong.
Recently, I embedded a BMP085 barometer in my autopilot board and operated it with this library: http://code.google.com/p/bmp085driver/
Barometers can be and are effectively used to calculate altitude, once initialized and zeroed.
So the figure above displays a short manual flight whose altitude is measured both by a barometer and a GPS. The barometer is zeroed upon power-up. The GPS altitude is zeroed, based on the altitude returned before taxiing. It is the time between 20 and 30 seconds. The plane lands at 150 seconds in the exact same place it took off. However, the GPS altitude measurement has already drifted 16m away.
This goes to show that GPS should not be used for altitude measurement, unless a very coarse albeit offset-free measurement is required.
A barometer is a much more accurate and fast device to extract altitude, when operated correctly.
Last Wednesday I went out to the field for some flight tests and gains trimming. Other people where flying their model planes there too. We usually follow a counter-clockwise pattern while flying to avoid collisions. That day I was flying especially slow, so when I took the turn, I did so on the spot and ended on the wrong lane. By the time I realized that, someone rammed me out of the air.
If I remember the even correctly, and the flight replay (LOG00212.kmz), the collision should be head-on. However, the reason I fell, was because the other plane's propeller clipped my left aileron. I managed to crash-land while doing semi-controlled spirals, losing a wing, the propeller and a wheel.
Afterwards, I tried to do some black-box analysis, with interesting results:
Firstly, here is a graph of the altitude, and the magnitude of the acceleration vector and angular speed vector:
The collision occurs at about the 120th second. I estimate the moment at 120.5s. Strangely, no acceleration or angular motion peak is noticed at that moment. Only after I try to pull up at 124s is acceleration recorded, and, of course, at the crash. The IMU is supposed to be set at +-8g limit.
The roll, pitch and yaw plots are a bit more indicative of the situation:
Roll goes crazy after I pick the plane up from the tail and carry it back to the car. It's expected.
In the last two graphs, a violent change in direction is noticed, in contrast with the first plot.
To sum up, I didn't find the accelerometers a good source of information, in order to detect a mid-air collision. Instead, angular velocities are more reliable, with proper thresholding.
Greg Walker, the director of the Alaska Center for Unmanned Aerial Systems Integration, preparing a drone for launching.
SAN FRANCISCO — As wildfire season begins in Western landscapes that were covered in smoky haze for weeks at a time last summer, the federal government’s firefighters are exploring the use of small remote-controlled drones with infrared cameras that could map a fire’s size and speed, and identify hot spots, a particular danger.
Follow @NYTNational for breaking news and headlines.
With a maximum wingspan of about 52 inches, the drones would supplement and perhaps replace manned surveillance aircraft, potentially reducing the risk to both pilots and firefighters.
But the effort is being slowed by Federal Aviation Administration regulations.
The use of drones in open airspace is regulated by the F.A.A., and its safety requirements effectively preclude unmanned aerial systems, or U.A.S.’s, from operating out of sight of a ground-based pilot. If distance or the smoke of a wildfire obscures a drone from observers on the ground, a piloted aircraft must be sent aloft to keep an eye on it.
“In terms of federal regulations right now, we can’t use U.A.S.’s out there except on a very limited basis,” said Ron Hanks, the aviation safety and training officer at the federal Forest Service.
Rusty Warbis, the flight operations manager at the Bureau of Land Management, said the process of approving individual trial flights was “cumbersome,” though improving.
The evaluations by wildfire experts are part of larger questions on how to incorporate these aircraft, originally used for military purposes, into civilian missions. The drones could complicate the main mission of the F.A.A., ensuring the safety of the country’s airspace. And observers in Congress believe that inherent distrust of government and privacy concerns are also slowing the introduction of firefighting drones.
Their potential usefulness, particularly their ability to pinpoint hot spots and fly in thick smoke that would ground other aircraft, was shown in an Alaskan fire nearly four years ago.
The fire, which burned over 447,000 acres — roughly half the size of Rhode Island — northeast of Fairbanks, was generating so much smoke that no planes were permitted to fly overhead. But a drone belonging to the University of Alaska Fairbanks was launched and easily identified the extent of the blaze and its varying levels of heat.
“The smoke was so thick no one was flying — that’s why they came to us,” said Rosanne Bailey, a retired Air Force brigadier general who is the deputy director of the Alaska Center for Unmanned Aircraft Systems Integration at the university. “We could fly and see the borders of the fire using infrared.”
Kent Slaughter, the acting manager of the Bureau of Land Management’s Alaska Fire Service, said it took four days to get the F.A.A.’s approval for that flight in 2009; the process is now down to about 24 hours.
But privacy concerns are slowing the integration of unmanned vehicles into the firefighters’ tool kit, said Senator Mark Begich, a freshman Democrat from Alaska. “Firefighting is a great example of how unmanned aircraft” are able “to determine the range of a fire, the intensity of a fire, without jeopardizing lives,” he said. “That’s a unique application, especially in my state, in Colorado, in California.”
He called the delays in getting approvals for testing the craft “frustrating.” The reason cited most often by firefighting experts is the requirement that the aircraft be followed and monitored by a chase plane if ground observers cannot see them through smoke, or because they are flying into canyons in steep and rugged terrain.
Les Dorr, an F.A.A. spokesman, said that safety in the air and on the ground is paramount and that the issue of line-of-sight requirements for drone use was being carefully studied.
The Army has lent the Interior Department 41 small drone aircraft that have been used for environmental monitoring, including tracking migratory wildfowl.
The Forest Service, part of the Department of Agriculture, has also been studying drone use for years. Mr. Hanks, of the Bureau of Land Management, said one question was how much value drones would bring to existing firefighting methods.
“We are still developing policies internally, what the cost benefit would be,” he said. The drones, Mr. Hanks added, “would be competing against what we could do aerially against a helicopter or a light fixed-wing airplane.”
John Gould, the aviation chief at the B.L.M., who along with Mr. Hanks is based at the National Interagency Fire Center in Boise, Idaho, had a similarly cautious perspective. “We’re trying to get them in the mix and put them out in the field to see the potential,” he said.
I want to let the APM trigger my camera and the camera I had did not have a port for a remote shutter trigger so I had to remove the button on the camera and solder the 4 points and connected them to a relay switch.
Raw flight footage.
Just to document some early progress in the building of a multirotor Conservation Drone with thermal imaging for wildlife research (last picture shows the quad with a FLIR PS32 camera, yet to be mounted). Apologies for the shaky video taken with an iphone (had to hold on to transmitter with other hand).
See: http://ConservationDrones.org for more information
Technical details:
Base unit: Reconfigured 3DR quadcopter with stock motors and ESC
Propellers: 10 x 4.5 SF props
Copter legs: improvised "foam noodles" (about $2 and surprisingly stable)
Battery: 2 x 5000 mAh Turnigy
Autopilot: APM 2.5 with power module, GPS uBlox LEA-6, Radio Telemetry
Firmware: ArduCopter V2.9.1b
APM parameter file: APMConfig_9XR_3DRQUAD.param
Flying weight: 1.8 kg
Total flight time: 21 minutes (17 minutes if flying with 1 x 5000 mAh battery)
Every year or so, some research group posts a video of a "cyclocopter" flying. I'm not sure why (this article suggest they might be more efficient than traditional helicopters, and that people have been pursing them for a century).
Anyway, here's the latest from a Korean university lab. I wish I could tell you more but their information link is dead.
R2 gangs roamed the halls!
As is customary and traditional, we celebrate every new 1,000 members here and share the traffic stats. This time it's 39,000!
There were 2 million page views in the last month! (we get around 65,000 pageviews a day on average). It took us just 24 days to get this latest 1,000 members--we're averaging one new member every 35 minutes.
Thanks as always to all the community members who make this growth possible, and especially the moderators who approve blog posts and otherwise answer questions and keep things ticking here.
Best Wishes,
Joshua Johnson - (Assistant Administrator)
Dear Friends,
our Flight Teams beta tester star to test a VR Copter Fly Cam configuration. This is the hexa copter used by our beta tester for doing this video :
The Hexa configuration use :
For obtain good fly performance we use this kind of for solve the iusse vibration this is the result of vibration during the flight. It's very good :)
Our beta tester use acro mode during his first fly test and he's very happy of result have with VR Brain Flight controll.
http://www.virtualrobotix.com/page/vr-brain-v4-0
for more info about the status of the project join here :
http://www.virtualrobotix.com/group/vr-gimbal-user-group?xg_source=activity
Data Bus mbed baseboards are now available on Tindie as a fundraiser! I figured maybe some folks wanted to experiment with their own algorithms and want a head start on their 2014 AVC ground vehicle entry. :)
I ordered a very small run from OSHPark (hopefully they arrive before June 8, but if not oh well), but will order more as needed.
Features
If there's enough interest I'll add some additional features.
This baseboard is in its fifth revision (version 4 was onboard when Data Bus took 3rd in the 2012 AVC).
Just get an mbed, load it up with my code ( and here), add an L3G4200D gyro, Venus or uBlox GPS, wheel encoders.
On Data Bus I run external power supplies, a separate encoder schmitt trigger board, a safety cutover so I can take control of the robot during testing, and I also run a Venus GPS, Pololu MinIMU-9 (for x axis gyro).
All the code is open source:
A few snap-shots of the action around our booth at Maker Faire Bay Area 2013. There are many more photos to sort through, but I wanted to share some now. The light was actually very poor inside the hall, not the best for photography.
From the top:
Brandon answers tough questions from a discerning customer; Brandon, Joe, and Justin; as a rule, kids asked the best questions and kept us on our toes; Andy was able to bring his family on Saturday, including his eight-year-old daughter who is a huge fan of flying robots; Carmen; John; Edna
As I already mentioned on the first page, mygoal was to construct a boat that could drive for at least 4 hours without charging while I could catch some fish :-). To reach that goal, my boat should weigh around 4 kg and the capacity of the batteries should be quite high. After a lot of searching in the internet, I decided to take LiFePo batteries, because they are supposed to have a gentle charging behaviour, they have a good Ah/kg value and you can buy them with a lot of Ah per cell. I finally got three of the Headway batteries put them into shrinking tubes and connected them to high quality cable and to a balancer cable. I also found a charger with a really good price that will charge and balance my batteries in the future with 6 ampere. All together I spend around 150€ on the energy system. I now have 15Ah with 11,1 Volts for a weight of 1,5 kg, which is very light in my opinion.
The motor was the next difficult part. How many turns per minute and what torque would I need for a propeller this size? I decided to buy two motors. One with a transmission of 1:6 and another one with a transmission of 1:11. A waterproof lid for easy and save access to the inside of the boat, a cheap digital 2,4 Hz 3-channel remote control, a motor controller for up to 15A and a steering servo made my boat ready for the first tests on the water to test the two motors with the different transmissions.
All the parts fit together perfectly and the radio controller worked great. I tested the boat in the bathtub first to see whether the stability was good enough for the test on the lake. It turned out, that the 1,5kg of the battery that I fixed to the bottom with hook and loop fastener, made the boat stable enough. I also checked the thrust of the boat in the small bathtub and the current consumption. At 11 volts, the 1:6 motor would take 1,9 ampere, with full thrust in stationary position (which is the worst case scenario). So the batteries would be able to supply the motor for more than 7 hours with full power, which was way better than expected. So the test on the lake could come.
On the lake near my home, the boat made a quite good performance. It was even stable in turns and the radio control worked perfectly. The speed was all right (around 4 km/h) for a long track via Ardupilot. But for a bit fun on the radio control, it could have been a bit faster though. So we didn’t build in the 1:11 transmission, and decided to buy the 1:2,5 transmission motor instead to test that one as well next time.
The long weekend brought my project a good step forward and in the next weeks, I will try to get the Ardupilot ready because in 4 weeks, I will be back in Sweden again, for the first real test.
I hope this project is interesting for some of you (even though it’s a boat and can’t fly ;-)) and if you like, I will share the future steps and the real test in Sweden of course.
Now my questions to those, who worked already with the Ardupilot and sounding:
In this blog I would like to share my experiences with my new project, an autonomous transducer boat, controlled by an Ardupilot.
After a long time of reading blogs, searching parts online and planning, I started my project. My plans are to build an Ardupilot controlled boat, which measures and logs the depths and the temperature along its path on remote lakes to be able to create depths and temperature plots of the lake.
The idea for the boat developed in my head after my last fishing trip to Sweden. I visit friends in a small village in south Sweden at least twice a year and I relax from work by fishing on the remote and calm lakes at that site. In the summer time, I am very successful in fishing and it’s very easy to catch several big fishes within a few hours. Since the lakes are frozen in winter, my friends and I tried to do some ice fishing but we didn’t catch a single fish even though we spend at least 7 days on the ice. We guess that we didn’t catch at the right spots because we have no idea, where the deep parts of the lakes are, and how the lakes look like underwater. After that unsuccessful vacation, I decided to build that boat so I won’t have to drive back home without a single catch.
Thanks to the two great blogs from Geir Andersen and Harald Molle:
http://letsmakerobots.com/node/21098
http://diydrones.com/profiles/blogs/ardupilot-goes-into-the-water
a lot of question regarding the sonar, the navigation and software were answered and my project could start. And these two blogs are the reason why I also share my experiences with you.
Right now, I work far away from home so I can only progress with the project every few weekends. I started 6 weeks ago with the most expensive and important part, the sonar. It took a long time to investigate, which sonar I could use and which sonar could communicate with my Arduino and after I finally accepted, that there is no way around spending at least 200€ for a good sonar, I bought the Intelliducer from Garmin and the communication between the Arduino and the sonar worked instantly. The most important thing about the transducer is that it’s a digital transducer that sends the information in NMEA 0183 language. The transducer is quite small, easy to include in the Boat, the resolution seems to be 0,1m (correct me if I’m wrong) and the maximum depths is over 300m. It also measures the temperature, which can be interesting for fishing as well.
The next stage of the project was the boat. I wanted to build a light and easy to realise boat, that is totally enclosed and waterproof. I also wanted it to be energy efficient and not too slow, so that the batteries would last at least for 4 hours and more than 10 km. I decided to use a torpedo design, since I could use cheap plastic pipes as the body. I only had to build the front and the rear part of the boat with fibre glass.
I could manufacture the positive Form with wood on the wood turner of my father.
After I produced a negative form around it by using bandages, I rinsed them with wax as a separator, and I started with the fibre glass. Even though the material of the negative mold seemed not to be the best for fibre glass I was happy with the results.
As propeller, I decided to use a kort nozzle from Graupner with 60mm diameter. In small speeds, the kort nozzle is supposed to be more efficient, and it also saves my propeller from rocks or other dangerous objects under water. For my boat with a diameter of 125mm the 60mm diameter of the propeller seems to be huge. But as an engineering student, I learned that a big but slow propeller is more efficient than a tiny but fast running one at the same speed. That was my progress for that long weekend and I was forced to take a break till last weekend, where I came home again.
In the first two stages, I invested around 300€ for the transducer and the boat body. The next stage would cost me another 300€ for the batteries and the rest of the electronic. The third most expensive part (after the transducer and the upcoming Ardupilot) is the battery. But will come on the next page.
This Blog is closed now from posting further comments as per the request.
Hmmm Now hobbyking is selling:
72 USD for the hobbyking APM 2.5 board
Are hobbyking selling this under license or is it a CN clone?
Can hobbyking use the name Ardupilot 2.5?
Some developments on 2.4GHz video link and 868MHz datalink antenna systems:
Measuring the 2.4GHz Antenna SWR
The Ground Tracking Antenna
This blog shows an integrated 868MHz xBEE datalink antenna and tranceiver and a 2.4GHz Video downlink antenna and transmitter as a single modular unit. Feed it 3.3volts and video as well as the autopilot datastream.
Also shown is a ground tracking antenna system. Two antenna are contained in the head - a multiturn 13dB gain helical antenna for the 2.4GHz video downlink, and a Diamond loop , over the ground plane, giving 8dB gain, for the 868MHz datalink. The antenna base contains a Lipo battery and fits onto a tripod. The base unit is then lined up with North, and the unit tracks the aircraft in flight using the A/C GPS position. Cable wind/unwind software is also implemented to allow the unit to unwind for example when flying circles around the GCS - this process follows a computed geometry to ensure minimum time pointed away from the A/C, and uses the aircraft flightplane to estimate the postion to slew to to start tracking again, if the link were lost.
We have just completed range tests, first with the aircraft mounted on a tall pole, on a high ridge in the desert here in Namibia. The aircraft was able to be rotated 360deg in azimuth and +- 25deg in elevation. Tests were conducted with the ground tracking antenna at 10km from the aircraft position.
Video TX power was 27dBM @ 2.432GHz, into the Skew Planar Wheel. Datalink TX was a 868MHz xBee Pro- range was tested at 25milliwat TX power ( can be set to 1mw, 25mw, 100mw, 200mw and 300mw - 1mw at 10km did not work)
Video was perfect picture with the aircraft at any azimuth or pitch angle ( combined) except for the Aircraft directly facing the ground antenna, at 0deg pitch - the A/C antenna is shielded by the avionics, the on-board IR gimballed IR camera, and the Lipo batteries. Tilting the A/C up or down 5 degrees brought the video back with perfect picture.
Datalink comms was constant with NO dropouts at 25mw bothe ends, regardless of the A/C attitude and azimuth heading. The aircraft was also fitted with 2.4meter carbon fibre covered wings - 315mm chord, and a carbon V tail ( very similar to my mk-I SurVoyeur A/C , only greater wings span and carbon wings.- see the SurVoyeur blogs..)
The Datalink antenna consists of two rings, spaced apart, and is a Slot Antenna, ie, the radiation takes place from the slot formed between the two rings. It is a narrow band antenna- not more than 20MHz bandwith for 1.3:1 SWR - at center frequency it is 1.05:1 SWR. The first rings were done in copper wire to determine the antenna factors, and then a PCB version made on the router, at various sizes, to determine the size reduction factors due to the PCB dielectric constant.
Wire Rings Versus PCB Versions
An Integrated model was then machined on the router - this module consists of the antena rings and is fitted with the xBee datalink module and serial interface electronics.
This module is later fitted with the Skew Planar Wheel 2.4GHz antenna, and with the video TX module.
The Skew Planar Wheel was constructed thus:
Pre-Cut element wires: Wires formed in a 'stretch' jig.
Wires Stretched and removed from jig
Wires Formed.
Coax End pieces about to be fitted
Coax End Pieces soldered to coax outer and inner
Antenna elements fitted to the mounting Jig and soldered to the coax ends
The 2.4GHz antenna is then fitted to the 868MHz module:
The Video Transmitter is fitted on the underside:
This assembly is then fitted into the antenna bay of the composite fuselage:
SWR measurements were taken in-situ to determine any de-tuning:
SWR AT 2.44GHz:: = 1.13:1
The ground tracking antenna basics follow:
This Consists of a base unit containing the Lipo Battery, the drive electronics, an azimuth servo drive and feedback mechanical system and a yoke carrying the antenna head. The antenna head contains the 2.4GHz helical antenna, the 868MHz datalink Diamond loop antenna, the Video receiver, the xBee datalink tranceiver, and the elevation servo with position feedback.
The Head unit closed: The base unit guts:
Azimuth Mechanics and feedback POT
The Helical and Diamond antenna in the head unit.
We then flew a max range test to see what a typicall max range might be - Video was lost at 39km, and datalink was still error free with 200milliwats at that range...Video was 'snow free' ( P4 signal) at 32km.
Joe
The Nampilot....
