Blogs

Today the Association of Unmanned Vehicles International (AUVSI) published a drone Code of Conduct. Here are some excerpts. What do you think?

The emergence of unmanned aircraft systems (UAS) as a resource for a wide variety of public and
private applications quite possibly represents one of the most significant advancements to aviation, the
scientific community, and public service since the beginning of flight. Rapid advancements in the
technology have presented unique challenges and opportunities to the growing UAS industry and to
those who support it. The nature of UAS and the environments which they operate, when not managed
properly, can and will create issues that need to be addressed. The future of UAS will be linked to the
responsible and safe use of these systems. Our industry has an obligation to conduct our operations in a
safe manner that minimizes risk and instills confidence in our systems.

Safety

• We will not operate UAS in a manner that presents undue risk to persons or property on the surface or in the air.
• We will ensure UAS will be piloted by individuals who are properly trained and competent to operate the vehicle or its systems.
• We will ensure UAS flights will be conducted only after a thorough assessment of risks associated with the activity. This risks assessment will include, but is not limited to:
• Weather conditions relative to the performance capability of the system
• Identification of normally anticipated failure modes (lost link, power plant failures, loss of control, etc) and consequences of the failures
• Crew fitness for flight operations
• Overlying airspace, compliance with aviation regulations as appropriate to the operation, and off‐nominal procedures
• Communication, command, control, and payload frequency spectrum requirements
• Reliability, performance, and airworthiness to established standards

Professionalism

• We will comply with all federal, state, and local laws, ordinances, covenants, and restrictions as they relate to UAS operations.
• We will operate our systems as responsible members of the aviation community.
• We will be responsive to the needs of the public.
• We will cooperate fully with federal, state, and local authorities in response to emergency deployments, mishap investigations, and media relations.
• We will establish contingency plans for all anticipated off‐nominal events and share them openly with all appropriate authorities.

Respect

• We will respect the rights of other users of the airspace.
• We will respect the privacy of individuals.
• We will respect the concerns of the public as they relate to unmanned aircraft operations.
• We will support improving public awareness and education on the operation of UAS.

Edward Burtynsky, who is famous for his huge landscape and mega-engineering photography, uses drones for aerial photography. From an interview:

Twilley: From the point of view of a photographer, then, it might seem equally interesting that there are now all sorts of new types of photographic systems on the rise—quadcopter-mounted 3D scanners, drones, and even smart ammunition equipped with cameras that can loiter in an area taking aerial photographs. Simply on a technical level, I’m curious about where you see the future of photography going. Do you see a time when you’re not going to be riding in a helicopter over Los Angeles but, instead, piloting a little drone that’s flying around up there and taking photographs for you? 

Burtynsky: I’m already doing it. 

Twilley: You have a drone? 

Burtynsky: Yeah. I use it to go into places where I don’t have any air space. I work with a team. One guy runs the chopper, one guy runs the head, and I take the shutter release and compose. For example, there is no civil aviation space in China, so I was using it there. I used it to shoot the big [Three Gorges] Dam area [shown above], and I used it to photograph agriculture. 

So I am already using that technology. It offers new ways of entering into places that you would never have considered going—or that you couldn’t even go to—before.

(Via Kottke.org)

Congrats to our friends at OpenROV, who hit their Kickstarter target in the first day! You can get the complete kit for $775. Right now it's just teleoperated, but it has a BeagleBone computer board, so there's lots of potential for sensor and autonomy later. 

Massimo Banzi, the co-creator of Arduino, gives a great TED talk on the power of open source projects. Gives a nice shout-out to DIY Drones, ArduCopter and MatterNet, which uses ArduCopters to deliver packages in places like Africa.

(via Makezine)

Hizook, one of my favorite blogs, has a great rant on one of my favorite peeves: UAV videos that show performance only possible with crazy expensive motion capture systems that are only found in a few well-funded university labs:

It also covers other sins of robotic demo videos, such as not being clear what's teleoperated and what's autonomous, speeding up time, tethering and scripting. Check out the whole thing, but here's the start:

Movies and scifi books inspire roboticists to push the envelope, but they've also skewed the public's perception of robot capabilities. This problem is being exacerbated by researchers.  In the last three months, I've had to shatter a few dreams: "Your $300 AR.Drone or $150 Ladybird will not be able to perform insane autonomous aerial maneuvers (yet). The UPenn quadrotors rely on a $20k-$50k camera-based (Vicon) motion capture systems, which provide global pose estimation of each UAV at millimeter-accuracies at up to 1kHz (and often uses an external, centralized motion planning computer too)."  That this crucial aspect of the videos does not register with intelligent people means that researchers are being disingenuous and violating their duty to the public -- which sucks, because their projects and research are awesome!   And this is just the example that happens to be most salient to me at the moment.  In this post I'd like to explore some "best practices" for robot videos so that we can quit misleading one another.

We proudly announce switzerlands first full range webshop for ardupilot ware, j-drones copter and videopiloting equipment.

Take a look. There are some APM 2.0 left in stock!

www.youcanfly.ch

See you there.

Remo

* as a new shop-launch there could be some bugs so please report any broken links or unusual behavior to info@youcanfly.ch

Okay, okay. I know what you are thinking... Didn't you learn anything from the last episode? We did, but this one totally surprised us. We were just going up for a few minutes to test the new antennas and a new field when we lost the plane.

So, what happened?

Not totally sure why the APM seemed to struggle to find it's way, and we may never know as we still didn't have the DF card working (it's showing an error, and we've tried removing and reinstalling, and updating the firmware, still no luck) and we don't have telemetry yet (it's in the mail!).

One thing is for sure though, the flight battery was not working correctly. One of the cells wasn't holding a charge very well, but it seemed to perform just fine at first. However, when we finally set it to RTL it just couldn't keep altitude, no doubt caused by a weak & dying battery.

We are learning a lot, and are gathering all your suggestions to make a big improvement episode.

This is so much fun!

Thanks!

-Trent & Nick

It's been a while since I've posted an update on the progress of the AutoQuad flight controller.  The event that we've all been waiting for has arrived with ST Micro's announcement and subsequent release of their STM32F4 product line.  As expected, the micro-controller is pin for pin compatible with their STM32F2 series which the AQ v6.1 hardware was designed for.  This meant it was a drop-in replacement.  The most important new feature of the chip is the implementation of ARM's Cortex M4 core with a hardware FPU!  This means that we can now do floating point operations in a single clock cycle.  All forms of add / subtract / multiply / integer conversion, etc are single clock cycle instructions with the divide and square root instructions taking 14 cycles.  This is a significant step forward for math hungry applications like AutoQuad.

As soon as I could get my hands on one (around November I think) I had it on a board working to port my ground Unscented Kalman Filter code to fit into the 168MHz MCU.  With some optimizations, it ended up fitting with processing room to spare.  The current version leaves ~40% idle time during flight.  The filter is interesting because it brings all of the important estimated states and observations under a single mathematical model.  This means that each observation can influence any number of state estimates if there is determined to be co-variance between them.  The theoretical performance improvements over my old fixed gain techniques is high.  17 states and 16 process noise terms are estimated at 200Hz observed by 13 sensor measurements.

A benefit to using such a filter onboard is that it can adapt to changing variance of sensors and measurements on the fly.  This removes the need to do ground based flight calibration simulations which was a drawback to the original fixed gain methods.  Once you have a calibrated IMU, it can provide accurate state estimates "out of the box."  While this is nice, the biggest improvement is the accuracy of the state estimates it can produce.  States like 3D accelerometer bias and 3D rate gyro bias are critical to accurate attitude estimates which is the only way that you can propagate acceleration measurements through velocity and position estimates with any kind of accuracy.

Other than the upgrade of the MCU, the hardware is mostly unchanged from the original v6.1 layout.  However, there have been a lot of new features added to the firmware since last year.  What I call DVH (dynamic velocity hold) allows the pilot to control the craft's velocity in 3 dimensions while AQ handles everything else.  Let go of the sticks and the machine holds position.  AQ now speaks mavlink so it can be configured and controlled from any ground station that supports the protocol.  A comprehensive parameter set has been established that allows configuration of almost all aspects of operation.  Gimbal support and expanded mission capabilities have been added.  1-wire support for pre and post flight communications with ESC32.  Too many more to list here.

With the help of Max Levine I created this video to demonstrate the autonomous mission capabilities of the current firmware (version 6.6):

If you use the uBlox LEA-6T as the onboard GPS module, AQ can record raw satellite observations to its uSD card along with the normal flight log.  With this data and data from a local base station, you can use post RTK to get extremely accurate position and velocity estimates (~ centimeter accuracy.)  In fact, I use the RTK velocity estimates as an absolute data point in scoring the filter's performance in the ground simulations used to tune the variance and noise parameters used by the UKF.  Future work might include onboard RTK calculations using a linux based application processor mounted on a daughter board.  This would bring the system's performance to an entirely new level.

Here is what the actual flight path looked like of the flight shown in the above video using post processed RTK:

I need to thank the small group of people who have worked very hard to test, write utility software and interfaces, create documentation and generally improve the AQ  platform.  It is still very far from a finished, polished flight controller, but it has come a long way because of their help.

As with ESC32, I have decided to release the AutoQuad FC firmware under an open source license.  It can be found at:

http://code.google.com/p/autoquad/

I would also like to invite anyone interested to participate in a public beta test of the system.   Sensor calibration, setup and configuration is still a lengthy and sometimes tedious process so I would discourage anyone who thinks they can bolt the board to a frame and start flying as that is not at all what you should expect.  I have authorized manufacture and sale by ViaCopter and Flyduino who are taking orders in a few days.

Check this out, from YouTube:

Heli stuff starts at 9:48

Hey, I found something interesting.

The big robotic eagle.

What you think about install ArduPilot on his Orithopter?

 check this link on youtube

jDrones News: jD-MediaTEK Backup Battery Tray

Few weeks ago we introduced our new and improved jD-MediaTEK GPS unit for all ArduCopter, ArduPlane and ArduWhatEver use. We also said that there will be shortly a new battery tray for it. Well here it is.

What does it give and what does it take. It gives to you and your GPS backup battery power for 8-12 months from regular CR2032 3V battery (according GPS module manufacturer). It also gives 2D/3D locks for you in 2-5 seconds in average. On our tests it's usually 2-3 secs until GPS module reports proper satellite lock.

Board has also small charge/keepup circuit that will powerup battery circuit in times when main power is connected.

What it takes: Soldering 4 support pins and one solder jumper. Job that usually takes only 3-4 minutes.

Without GPS module on top it looks like this:

As you can see it uses regular CR2032, 3V battery that you can find from almost every "7-11" shops around the world. This battery will power internal RTC clock for 8-12 months in normal conditions according GPS module manufacturer. 

If you ran out of battery later on, don't worry. Battery is really easy to replace. Just slide old battery out sideways and put new one in and off we go again for next 8+ monts.

Get your own battery tray from jDrones or jDrones distributors around the world.

jDrones store: jD-MediaTEK Battery Tray

Battery used: CR2032

Codebender, a cloud-based IDE for Arduino is coming soon. If you like the look of it, you can back it on Indigogo (28 days left).  I backed it at the $150 level, which gets you and Ethernet Arduino, with a special bootloader that lets you program and download code from the Web. 

From the site's description:

Time to revolutionize the way you develop and hack on your projects. codebender is a platform that helps your next idea come to life. Wether you are a maker, a hardware hacker or an artist, codebender allows you to code on the web, faster and easier, using our awesome web editor. Host your Arduino sketches on the cloud and use our next-gen compiler to build and debug your sketches from your browser. When you are done, upload them to your Arduino, straight from your browser. No installations required. Coming soon. 

This seemed to get very little uptake in the mainstream media... perhaps for the better.  Nevertheless, I thought it was worth sharing here:

From the article:

Two Marin County men were cited by federal authorities over a drone helicopter buzzing around Alcatraz Island, the National Park Service reported.

The operator of the remote-controlled helicopter, which is equipped with high-definition cameras, was Devin Hedrick, an aerial photographer who lives in Greenbrae. Hedrick's service, Hover Effect LLC, offers airborne video and still photography for real estate listings, music videos and television shows.

On Tuesday, working from a boat on the bay, Hedrick was operating the electric helicopter for a client, Bruce Paquett of Sausalito, whose project involves images of Alcatraz. According to park service spokeswoman Alexandra Picavet, the helicopter, which has a rotor span of about 6 feet, was flying low around the island, frightening the birds and swooping over the tourists' ferry dock.

The U.S. Coast Guard, carrying a National Park Service ranger, approached their boat and confiscated the video. After watching it, the park service issued citations to both Hedrick and Paquett.

"Their own footage showed us what they were doing, which was scaring the shorebirds from their nests and getting too close to the people on the dock," Picavet said.

Hedrick was cited on suspicion of disturbing wildlife, operating aircraft within 500 feet of a boat dock, creating hazardous conditions and operating an aircraft within the Federal Aviation Administration-imposed closure of 2,000 feet above the island.

Paquett was cited on suspicion of filming without a permit.

Alcatraz is part of the Golden Gate National Recreation Area, which is managed by the National Park Service.

Hedrick, reached by telephone, said he thought the boat was 500 feet away.

"There certainly are some things I should have been more clear about, instead of just taking the advice of the boat driver," he said.

This is a quick update for the Arducopter SIM and 2.6.1 development:

There is quite a bit of development going on right now, but I thought I'd share what I'm working on. I'm using Flash to implement a simulator and test Arducopter code. What's on my site at jasonshort.com is on the current Trunk. 

What isn't there is a whole lot of other work including Tridge's DCM core updates and Andreas' APM_limits code which is a geo-fencing library. 

You'll notice the sim has been updated to work in 3D now, so you can fly full missions, Yaw and Loiter in 3D. An orange line now indicates nav_yaw which is the yaw hold angle. A black circle indicates the GPS positions and the red box is the next waypoint location.

A new crosstrack algorithm:

Based on our flights in high winds at the Copter Rodeo, I set out to improve our crosstrack error correction. We had previously been using Arduplanes' track correction which turns the plane into the error to correct it. Of course copters can fly sideways and don't need to give up forward momentum to track correctly. The new algorithm solves this and acts very similar to the loiter control. Crosstrack gain will be lowered to a default of .2 because of new approach.

GPS lead filter:

Another idea from the rodeo, the lead filter takes into account the velocity and acceleration of the copter and the latency of the GPS to guess where the copter really is, not just where it was 1 second ago. This helps Loiter somewhat, but where it really shines is the Waypoint and RTL navigation. When you hit the WP it acts immediately, and not 1 second later which helps reduce overshoot.

Altitude hedging:

Phillip Jones suggested prioritizing the altitude over navigation when fighting wind to prevent the quad from loosing altitude during a hard pitch. This keeps the quad from hitting the ground during WP flight. Anything greater than a 1m error begins to level out nav_pitch to gain altitude. Still a WIP and not on the trunk yet.

RTL:

RTL_altitude is now implemented. This will cause the copter to rise to the desired altitude in Loiter before heading home. The parameter rtl_approach_alt will change how the copter will land after RTL or a mission that doesn't end in a land command. Basically setting this param to 0 will cause a land, setting this to any other number will cause the copter to go to that altitude after RTLing. The param auto_land_timeout is used to trigger this altitude change. The RTL Approach altitude parameter is great for bringing the copter down without worrying about touching the ground.

Alternate Yaw control:

A new control method for Yaw goes back to the hybrid rate/stabilzie approach, but uses a timer to lock in the hold angle. This allows the rate controller to brake the Yaw and then set the new hold angle without much overshoot and dreaded snapback.

Better Yaw gains:

Testing the SIM with an out of alignment motor allowed me to test various I term settings. An iterm of .02 for BOTH Rate and Stabilize Yaw works best.

Discovered Yaw Bias issue:

While running missions in the sim I realized the copter would run off track while Yawing to the target. Turns out we change and update Yaw continuously, but the copter's nav_roll and nav_pitch is only updated 4x with GPS reads. This causes the copter to be pitching at at angle to the target instead of towards the target when Yawing. The nav_roll and nav_pitch are now updated at 50 hz instead of 4 which get's rid of most of the issues.

Self centering throttle:

This is very experimental, and probably won't be enabled by default. The throttle cruise value is calculated at all times, and the lower limit of throttle is raised to place that cruise value right at mid stick. 

Drag/velocity estimation:

Takes the desired velocity and outputs a pitch and roll that should match the drag of the copter. This lets the I-terms deal with just the wind and not the wind + drag combined. It also helps the track accuracy by about 30%.

Alt Hold:

"Angle boost" a more accurate algorithm in 2.6, but we found it didn't account for the inefficiency of the thrust pattern. A small correction has been added to account for this.

Throttle min and max 

Implemented the params for throttle min and max so you can change them from the MP.

What's new with the SIM:

Added new top view

Added 3D physics

Added the ability to run the SIM at up to 10x speed for running variations

Added a Score for integrating crosstrack error to use for gradient descent (machine learning)

Added a new joystick controller class that acts like a real radio, or allows user to adjust 1 axis only.

Added 2D wind

Added Yaw Gains

Added iteration # limit to stop the sim after N number of 100hz main loops.

What's next in the SIM:

Mission editor

If you are testing the trunk, please check the SIM and see if you can reproduce bugs. If not, please note that in bug reports.

Code is here:

http://code.google.com/p/ardusim/

Flash FLA project file available by request.

Jason

Video from WIP last week.

As part of a friendly bet with Trappy on facebook, Andreas built and flew one of his signature wooden quads in under an hour.  A more detailed build video is being edited, but here's a timelapse of the process.

From Gizmodo: 

Military drones rely heavily on GPS for navigation guidance while in the air. But in areas where a signal can't be found, or where someone is using a GPS jammer, a drone will find itself in a troublesome predicament. Military sub-contractor BAE Systems has come up with a solution to that problem: Apositioning system called NAVSOP that uses any wireless signal to find its location.

The genius of NAVSOP (Navigation via Signals of Opportunity) is that it really doesn't matter what the signal is. It can be a TV signal, radio signal, wi-fi signal, or even a GPS jamming signal. And the part that excites BAE is that the infrastructure is already in place. They don't have to build out a network of transmitters. What excites us is that it works indoors, meaning if this was integrated into all navigation products—and not just military tools—we could have powerful location assistance services indoors and in dense cities. The BBC says that the NAVSOP box requires GPS at first to learn about its surroundings. But over time as it amasses a database of location information, it will become less and less reliant on GPS.

The system is currently a prototype box that can be linked up to whatever is in need of navigation assistance, but BAE believes it can be shrunk down into a dongle-sized package.It's like the navigation equivalent of the tech Bruce Wayne used in Batman Begins to see through walls using people's cellphone signals. [BAE via BBC via Engadget]

Hackaday found a paper that describes a GPS spoofing technique that may be similar to that used by Iran to bring down a US drone. From the paper's abstract:

In this paper, we investigate the requirements for successful GPS spoofing
attacks on individuals and groups of victims with civilian or military
GPS receivers. In particular, we are interested in identifying
from which locations and with which precision the attacker needs
to generate its signals in order to successfully spoof the receivers.
We will show, for example, that any number of receivers can
easily be spoofed to one arbitrary location; however, the attacker is
restricted to only few transmission locations when spoofing a group
of receivers while preserving their constellation.
In addition, we investigate the practical aspects of a satellitelock
takeover, in which a victim receives spoofed signals after first
being locked on to legitimate GPS signals. Using a civilian GPS
signal generator, we perform a set of experiments and find the minimal
precision of the attacker’s spoofing signals required for covert
satellite-lock takeover.

You may offend roommates, partners and other living beings.

As some of you know i have been trying to get my heli to Loiter since last year. Today i got the heli to Position Hold for around 3 mins, it would have gone longer but it was blowing a gale, and starting to rain, so i cut it short.

So after a few more tests with this heli, more tuning etc i'll be starting the on the much larger Gas Helicopter, 23cc. 

I tried to download the logs but didnt really get anything out of the APM that would have been any use. 

Sorry about the poor quality of the video, i only had my stills cam with me, but you can see from one shot i'm pretty relaxed letting it fly. The Loiter P value is down to 0.100 which is really low, i may raise it slightly, will wait for a much calmer day to get better results. The CH7 autotrim worked really well, had to do it on  windy day but no choice. 

I'm going build on this test and try to get the razor more stable. 

Thanks to Randy, Robert for the Heli code, Martin @ buildyourowndrone, and all the other programmers, testers, builders,  for all your hard work.

After the Latest Skywalker crash I decided that the build-fly-crash-build-(repeat) process was too slow, and I wasn't learning as fast as I'd hoped. 

I'd seen an ad at Hobby King for $20 Quadcopter frames... sounded like a good deal and I already had a matched pair of motors/ESC and APM2 so I decided to take the plunge and order the balance of the components needed to build a basic quad copter.

The motors were Detrum 810kv's with 25A ESCs from HobbyPartz.  I'd picked them up to experiement with twin fixed wing stuff and small wings...

Assembly was easy, though I was short on bolts/screws.  No big deal.

HobbyKing 550mm Quadcopter frame

4x Detrum 25A ESC

4x Detrum 810kv

APM2

Below are pictures of the finished quadcopter and then some videos from today.  My 11 yr old was cameraman... kinda shakey...  Yes, the "fuselage" is a potato salad tub from a local deli.

https://www.youtube.com/watch?v=OlHMXWs-exQ

https://www.youtube.com/watch?v=nVfJLeLKtEA