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3D Robotics

More housekeeping: new Forum and Blogs tabs

Posted by Chris Anderson on February 24, 2009 at 9:35am
I've finally gone through all the discussion on this site and categorized them so they can be more easily usable. You can see all the categories and the discussions in them by clicking on the "Forum" tab at the top. Please remember to select an appropriate category when you post a new forum topic. As for blog posts, they operate a different way, using multiple tags rather than categories. So please add tags to your blog posts, so people can find them! I've also added a Blogs tab at the top, so you can see all blog posts, as well as them sorted by date and tags.
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3D Robotics

Switching your ArduPilot power to a separate battery

Posted by Chris Anderson on February 22, 2009 at 8:00pm
ArduPilot has a built-in power regulator, so you can power it from a separate battery at anything from 5-15v. To do this, you have switch the solder jumper from the default RC power to battery power. This means unsoldering the solder jumper that the board ships with and resoldering it on the other side. These pictures show the difference (apologies from my crappy soldering on the second one):

One thing to keep in mind if you make this change: Unlike the standard setting, if you use BATT input it will only power the ArduPilot board; it will not power your RC receiver or servos. They must have their own power supply, such as a receiver battery pack or ESC for an electric plane. This is designed for people who fly gas planes (no ESC) and want the RC system on a separate power circuit so the autopilot can't drain that battery. If, however, you want to to power both the RC system and the ArduPilot board from the same source, leave the board in its default setting and connect the battery straight to the RC receiver; the receiver will then power the ArduPilot board.
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T3

roll-pitch demo firmware for the UAV DevBoard

Posted by William Premerlani on February 22, 2009 at 4:00pm
For those of you who bought a UAV DevBoard and who also live some place too cold to fly yet, I just finished a "roll-pitch-yaw demo" that you can use to show off your board. Firmware, documentation, and more details are available in a discussion of a direction cosine matrix estimator.Also, here is the firmware and documentation.The demo is rather impressive. It is a milestone in the project that I am presently working on with Paul Bizard. It uses mostly gyro information to compute the direction cosine matrix that specifies the relative orientation of two cartesian coordinate systems. In the demo, the cosines of the angles between the axes of the board and the vertical ground axis are output to 3 servos. Roll-pitch performance is smooth, accurate, and drift-free.The demo is fun and easy to run, does not require a GPS radio, does not require you to go outside, and will impress your friends.Bill Premerlani
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3D Robotics

Reloading the Arduino bootloader

Posted by Chris Anderson on February 21, 2009 at 9:00pm
If at any point you've managed to crash the ArduPilot code so badly that you've nuked the bootloader, don't worry: you can reload it. You'll need an AVR programmer. The best way to reload the bootloader is with the Arduino IDE, which is pretty straightforward. Just plug in your AVR programmer and select Burn Bootloader/ w/ AVRISP mk II. If you've already loaded AVR Studio, you may get an error in Arduino that says it can't find the USB. That's because of a driver conflict with the AVR Studio driver. Follow this workaround to reload the correct driver. It is also possible to load the bootloader with AVR Studio. Follow these instructions.
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3D Robotics

ArduPilot GPS lock bug fixed

Posted by Chris Anderson on February 21, 2009 at 5:00pm
Thanks to Rusty's detective work, I think we've fixed the GPS lock bug (the blue LED was turning off even when the module was showing valid data). New code is here. (Basically every instance of "if (fix_position == 0x01) ..." should have been "if (fix_position >= 0x01)..." It turns out that there are three valid fix values: 1,2 and 3. See the datasheet for more.)
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3D Robotics

Arduino 13 bootloading hint

Posted by Chris Anderson on February 21, 2009 at 9:18am
If you're having trouble flashing the ArduPilot code with Arduino 13, try upgrading the bootloader on ArduPilot to the latest version. You can do it with your AVR programmer in the Arduino IDE or use AVR Studio to program the board with the ATmegaBOOT_168_diecimila.hex file found in the Arduino folder hardware/bootloaders. I was having that problem and this fixed it for me.
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Can Ardupilot use magnetic heading vice GPS

Posted by Payne Kilbourn on February 19, 2009 at 10:32am
I am interested in using the ArduPilot on an autonomous surface marine vehicle to control the rudder. The vehicle control system is predicated on having the vehicle's bow (front) pointed in a steady direction; not on having the vehicle make a specific course over the ground. The vehicle has a flux-gate electronic magnetic compass that provides NMEA data on heading. What would be required to modify the code to replace the GPS heading with heading from the compass?Thanks
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First screen shot from the ground station software in c++

Posted by Viper UAV Project on February 19, 2009 at 9:00am
Hi this is the first picture of the ground station software i write for my xbee remote.I got the horizon done, but to the lack of missing imu yet , i can only test it via keys, whats not so nice.

The compass works already with the gps data, and also indicates with the green ball where the copter is goinging in the moment. and i als want to incorporate the field of view of the cam so you see in the compass where your camm looks.Beside that , this is the data i recive from the xbee propeller setup its 70 bytes due to the high number of floats i have.but i think its possible to trick a bit with some and pack them in a byte.And i send 8 bytes to it to control the copter.But i think i have to go with hardware serial sync to get a bit better and faster rates. 30 fps is right now the maxwith this much data, on loss rate of 0.01%With the horizon i want to make a second screen where it will be a bit bigger and have instead of the blue an orange back round live video feed. like in a real HUD.More to come.. soon
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3D Robotics

Update on ArduPilot code--final NMEA release

Posted by Chris Anderson on February 18, 2009 at 9:25pm
Jordi has been flight testing ArduPilot all week and we've got a raft of new code to share over the next week and an exciting new dimension of ArduPilot to reveal. First, today's installment: an updated version of the standard ArduPilot code, with PID loops improved and some bugs caught. You can find the code here. This is the last version of ArduPilot that we will be releasing with a NMEA parser. Although NMEA allows you to use any GPS module with ArduPilot, it's inefficient and ultimately limiting in accuracy and reliability. Going forward we will be supporting SirfIII binary mode with the EM406 (if you have one, there's nothing you need to do to switch to that mode; the code will do it for you) and the Ublox 5Hz modules. Everyone with the recommended combo of ArduPilot and EM406 are fine. Those of you with other GPS modules are also fine for now, in that this is the latest and greatest code for this version of ArduPilot, but you won't be able to migrate with us to the next version. (Although you can always tweak our code for your own GPS if you want). All this is the lead-up to the next release, in a few days: ArduPilot with built-in stabilization and navigation, flying great in a plane you may recognize ;-) More later..
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UAV Project Update - February

Posted by Jeremy on February 18, 2009 at 12:12pm
This is the second post I have made that is an update to my initial project design to make my fully autonomous aircraft. Our team has made a fair amount of decision making sense my previous post. Just for reference, the official name of our project is now "FlySpy".Airplane Selection:We have chosen the Easy Glider Pro from multiplex. Although it does not have as much internal space as the Easy Star, we fell that ailerons were a must for our application which Easy Star doesn't have. We have completely assembled the airplane and have flown it once. (No one on our team has experience flying RC Airplanes so we have an official pilot from a local UAV Imaging company. It would be nice for someone on our team to have experience flying but we do not want to use our project as a test dummy.) We are using the Power Pack and Servo pack that are made for the Easy Glider Pro. The motor seems beefy enough to support a flight with our components added to its weight so we do not intend on buying a bigger one.Battery : EVOLITE Li-Po 7.4V 2500mAh BatteryAutopilot Module Component Selection:Microcontroller - Microchip PIC24FJ256GA1103 Axis Accelerometer - Analog Devices ADCL3302 Axis Gyro - InvenSense IDG 300Barometer - VTI Technologies SCP 1000Range Finder - LV-MaxSonar-EZ1 Sonar Range FinderGPS Module - uBlox LEA-4P and getting Sarantel SL 1201 (Geohelix P2)SD Card Slot - TBDI have obtained a Niko Cool Pix s7c from a friend to use as an onboard camera. I am still working on decoding its push button pins so our Micro can turn it on/off and control the shutter.Topics we are contemplating:Powering Autopilot Devices - Everything that we are using runs off a 3.3V Vdd. We are uncertain if it would be okay to use the power rail coming out of the speed controller and sending it to a voltage regulator. We estimate our devices drawing about 157mA when everything is operating. Is this the usual solution or do we need to run off of two battery sources?Gyro & Accelerometer Data - I am still in the process of researching what are the best algorithms to fuse the data between the gyro and accelerometer to get a good orientation reading.If you are interested in looking at our progress, you can always look at our team website. Or if you want to go more in detail about my day to day discovery, you can look at my notebook.
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Gyro based Gimble

Posted by Dave Skala on February 17, 2009 at 11:58pm
Good day everyone. I never post because I'm a busy guy but hey, let's take advantage of everyone's Expertise!!Here's my current project:We have contracts with Forestry related clients. Currently we haul Repeaters and cellular links up to 3000'AGL to supply them with instant radio/cellular communications. Our system is solar powered and stays aloft for about a week at a time.Recently we were asked to set up camera racks on a picovet for it and so the projects begin!We are using standard off the shelf Pan Tilt Zoom dome cameras (Like store security uses) with a 5.8Ghz downlink for video and pan. We control the system using a joystick and DVR / software package..Our issues so far.Leveling is ok with the Picovet system and keeps the rack fairly stable. Software will handle most of the bounce BUT sometimes the balloon does a complete 360! When this happens, we lose our targets. We will rarely go to full zoom (X30) and normally no more than X15 zoom.We are thinking of two options:Make a 360 pivot point with a slip ring system and a heading hold gyro that will rotate the entore camera dome when a gust hits... (or something like that)ORFigure out a way that a program in the controller could rotate the already exhisting pan of the dome to compensate for balloon drift. Maybe a compass lock sensor of some sort? but could it be piggybacked on that 5.8Ghz video signal??Ideas???? Want to help us?? or be a contractor for this project??Let us know.Thanks again,Dave SkalaAerosight.com
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Government charges woman with illegal export of autopilots to China

Posted by James Ross on February 17, 2009 at 4:25pm
If you're about to deal with interested parties overseas, consider this:Maryland woman charged with illegal export of miniature aircraft controls to Chinatext_link.gif
WASHINGTON (AP) — A Maryland woman was charged Friday with exporting miniature controls for small unmanned aircraft to China.The government says the controls are the world's smallest and involve a technology that cannot be shared with China because of national security concerns. The devices can be used to fly small military reconnaissance planes.Yaming Nina Qi Hanson of Silver Spring, Md., is accused of taking the controls to China last August without a required export license. If convicted, she faces a maximum sentence of 20 years in prison and a $1 million fine (emphasis mine -J).Qi Hanson and her husband, Harold Hanson, arranged over e-mail to buy the controls from a Canadian company, MicroPilot of Manitoba, according to the criminal complaint. Company officials told the couple they could ship the controls to the United States but the couple would have to get an export permit to send the controls to another country.
Read the full articleIt doesn't really help anyone here to have the government use this incident as an excuse to crack down on amateur unmanned aerial vehicles. So please don't do anything stupid like this.
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3D Robotics

Status update on ArduPilot production

Posted by Chris Anderson on February 16, 2009 at 10:34am
Here's a Sparkfun engineering report on those last few boards that got out with incorrect fuse settings. Short form: the glitches from a few weeks ago should now all be gone: "A small number of boards that did not have the correct fuse setting got mixed into the batch that are correctly programmed. Currently, production is programming the correct fuses on all new builds. I am getting someone to go through our storefront stock right now to make sure the correct fuse settings are programmed. So, all boards from now on will have the correct fuse setting and boards sent out after 2/5 that do not have the correct fuse setting should be minimal anyway. Sorry for the confusion and we are sending new boards (hopefully with correct fuse settings now) to customers that have issues and do not have AVR programmers."
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Moderator

Wing upgrade for Superstar (SPAD wing)

Posted by Gary Mortimer on February 16, 2009 at 5:46am
Quite by chance I had a Superstar.When DIYdrones first flighted I was amused to see one being used and I think I have seen in somewhere in the East a military one.

That one having an off and landing on a house which made the local papersAnyhow, after many many fun hours teaching three or four people to fly with the Superstar, whilstI was overseas my young aviator decided to use the Superstar as a chuck glider from the top of their climbing frame.This went well for several flights so I am told, the garden being on a slight slope allowed the Superstar to fly all the way to the bottom.It was not perhaps designed for such things.I was slightly miffed bcause I had recently stripped the covering as it was tatty and the aircraft was now a spirited red.Well the wings were, the fuse had only been started.To cut a long story short, more out of boredom but also out of a desire to prove Dean wrong.For it is he that said he had failed to find an aircraft that the Attopilot could not fly.I determined to make a set of wings, with my boys,from some roofing foam that we had. The fuselage we simply nicked some correx signboards and glued them onto the gaps.Later having flown it, I thought that if I got to 5 hours flying time I would put the dimensions out there so that somebody could do a better job!All we did was tape some dowels in it for strength, cutting it first to what looked the right size in proportion to the airframe. Its a polyhedral 5% crank at the centre 15 at the tips. Again that just looked right.The aerofoil was a soldering iron cut steeper at the front shallower at the back.Then everything was taped together with reinforced tape.Just yesterday I measured it for the first time, the tips are 30 cm and main 90 cm each side making a total of 2.4m Cord 30cm. Quite a neat number for something that was just done by eye!To make things look right on the airframe, the weight and drag of wheels was forgotten.Looked like the thing was going to be short coupled so I increased the length of the rudder and elevator to bring things back a bit.For the first flight it was plain that we needed to strengthen the middle a little as the wings virtually tried to clap. But it flew.On the third flight I added my co pilot, because I also wanted to explore rudder elevator only with the co pilot. I forgot to mention no ailerons in this bird.In the three aircraft I have tried with rudder elevator and co pilot I have found that as long as the gain is reduced the co pilot handles it pretty well. This particular wing has quite a dihedral and the aircraft is inherantly stable.Test flying commenced on the 31st of January and 16 days later after 33 flights 5 hours have been achived, it would have been quicker, but the weather has not played ball.Now done properly, perhaps a built up wing or even a better foam one, properly cut, I am certain the performance will improve.A wing upgrade for your Ardupilot equiped Superstar will increase useful load, and time in the air.I'm using a Dualsky 50 equivalent motor, RAM 12 x 6 prop, 40 amp esc and 3S 2100 lipo.I'm sure somebody here will come up with a neater solution, but I know these measurements work for me so they should for you!With a better matched power set up with electric prop lighter wing and no bodged tail I'm sure an hour would be possible.

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T3

update: GentleNAV RTL firmware revision & IMU progress

Posted by William Premerlani on February 15, 2009 at 1:46pm
This is an update on two topics.1. A minor revision to GentleNAV RTL firmware.2. Progress to date on an algorithm to combine 3 axes gyro, accelerometer, and GPS information.1. While working on my next project, I discovered a minor error in the GentleNAV RTL firmware that runs on the UAV DevBoard.There are adjustments in the GentleNAV firmware to the pitch and yaw gyro signals to compensate for variation in A/D conversion of the gyro signals due to changes in battery voltage. Unfortunately, in doing the port from my previous board to the new board, I added the correction instead of subtracting. I did not notice the error during testing because I supply my board with regulated 5 volts from my electronic speed control.Anyway, I have revised both the code and the documentation.2. In case you are wondering what my next project is, I am presently working with Paul Bizard on a simple, fast, accurate algorithm for combining gyro, accelerometer, and GPS information into an estimate of the orientation of a plane. We do not have all of the details worked out, but we are making good progress.Today I implemented one of the components of the algorithm. Paul and I refer to it as update and normalization. It is a routine that uses gyro information only to update a matrix of direction cosine factors and maintains the orthogonality conditions. It works quite well, the drift is extremely low, on the order of a degree per minute. I can spin the board 10 revolutions forward and then 10 back, and the orientation estimate returns to the starting point.The bulk of the implementation uses vector and matrix library routines furnished by MicroChip that they tailored to the dsPIC30 hardware. Execution is very fast. Total execution time so far is 200 microseconds every 20 milliseconds using the 16 MHz clock.The next step is to adjust roll and pitch drift with accelerometer information. When I get that done, I will make that firmware available here as a demo.After that we will adjust yaw drift, and make adaptive gyro gain adjustments. We do not have all of the details worked out, but because of the astounding precision of the unadjusted algorithm, I do not think it will be very difficult.Bill Premerlani
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Ardupilot activating a Canon camera running CHDK

Posted by Nick Sargeant on February 15, 2009 at 6:46am
I'm looking to get the ardupilot to take photo's using my Canon camera that runs CHDK perhaps when it reaches a waypoint.CHDK has a USB remote shutter function described [URL=http://chdk.wikia.com/wiki/USB_Remote_Cable]here[/URL]Im not sure if any of you have experience with this, but I am right in thinking all i would need to do is get the ardupilot set one spare pin to HIGH for say 200ms when it reaches the desired waypoint?Also, on a side note, I would like to buy the Xbee Pro 868 dev kit but I'm having trouble finding a distributor that would get it to Australia for a reasonable price.Would anyone in the US with a reputable record on DiyDrones be willing to forward this to me in Australia? I would cover all delivery expenses of course.Thanks for your help.Nick
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ArduPilot installed in plane, indoor testing and simulations done

Posted by Michal B on February 15, 2009 at 12:30am
It's still freezing cold outside, so I'm playing by PC with more simulations.My first UAV is ready to go, for now I hooked by FTDI cable to PC, and checking if everything is OK, before going out to make a real flight.The plane may look fragile and ugly, well it is, but at present it is my working plane which I'm used to. Also it was cheap, and is very easy to cut holes in it for adding more wires and putting in more electronics. It weights about 400 gr. Once I make this fly and tested, I plan to go higher to a new 1100gr fuselage.My simulation setup is described in this blog.I run the simulation, and watch if real plane turns servos as expected. Only motor signal is disabled for now (don't need too much wind on my table). All looks fine, so now just waiting for springtime...Plane details:

And ready to fly:

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