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3D Robotics

Another autonomous blimp

Posted by Chris Anderson on May 1, 2009 at 10:15pm
Another autonomous blimp, this one clearly modeled closely on Blimpduino (right down to the same Lego parts for the vectoring servo--hey guys, how about a callout?) but using a PIC chip rather than Arduino's ATmega. Also a simple IR-based remote, rather than RC. Major DIY plus points--the Colorado State team who designed it built their own IR beacons. But because they built it on a breadboard rather than a custom PCB, they're way overweight for the envelope, hence all the extra party balloons!
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3-D on the cheap!

Posted by rad man on May 1, 2009 at 7:30pm
While searching on my second favorite blog site, I stumbled upon a commercial 3-D printer for under.......$70,000? nope $30,000? wrong again! $3,000? WRONG! for under $1,000 the average Joe can now have his or her own 3-D printer! Unlike traditional 3-D printers which melt layer after layer of expensive nylon the CupCake CNC machine extrudes layers of HDPE or ABS plastic! The only negative I see out of this machine is the extrusions are about 1/2 of a millimeter instead of .1 millimeters. Then again I would be willing to sacrifice a little bit of detail for a lot of savings! Now if any part of your UAV breaks then all you have to do is "print" a new one! here is the website to the wiki (www.wiki.makerbot.com) and to the store(www.store.makerbot.com). Also there is another website called "Thingiverse" (www.thingverse.com) which is basically a youtube for all the "things" people create in CAD programs! This project was inspired by a project for affordable printing called all machines a RepRap machines, but this machine is a RepStrap which means it can actually print out a RepRap machine. (www.RepRap.Org)IF THIS IS A RE-POST LET ME KNOW! ill remove this if it is.

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Moderator

UAV Seagull 2200

Posted by Robert Krogh (hooks) on May 1, 2009 at 12:30pm
Now my Seagull 2200 are ready for first testflight. I have uploaded the ArduPilot_EasyStar_WP code on the board so I "hope" it can make a testflight so I can optimize here and there...The seagull 2200 is a very stabel mashine modified with a stronger motor and a bigger prob.

Offcause I will post opdate on the comming up testflight and changes on boardcode for this model. Hope to make some videodokumentation also.I have one problem with the pre test- I installed the FMA sensor just like instruction. But when I point the nose down the pitch also going down.. so I need to reverse the settings. I'm using code 2.0 and not the new 2.1How to do?
Find more videos like this on DIY Drones
Here is the solution:In the 2.0 code, try this:Reverse IR sensor-old code-return constrain((int)(((infrared0-511)*90)/max_ir),-60,60);new code-return -constrain((int)(((infrared0-511)*90)/max_ir),-60,60);Reverse IR sensor pitch-old code-return -constrain((int)(((infrared1-511)*90)/max_ir),-60,60);new code-return constrain((int)(((infrared1-511)*90)/max_ir),-60,60);Just reverse the sign in front of "constrain".
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UAV Playground 1.2 - An approach to Unmanned Aerial Vehicles

Posted by jaron on May 1, 2009 at 11:30am

The UAV Playground is a collection of software components I've written in Java. They extend the Processing Development Environment (PDE) with some functionality that can help you to simulate and test different aspects of UAVs. You can as well use the UAV Playground library outside of the PDE in any Java application.UAV Playground and all the Software it is based on are freely available. The distribution and the source code can be found on the Open Source project page at code.google.com/p/uavplayground.The whole project is a work in progress and will be extended as I work on the exploration of UAVs. I'd appreciate if you leave me a comment or even better contribute to the project.Features- object oriented- modular- extendable- freeHow to use it- install the Processing Development Environemt (PDE)- download the UAV Playground distribution and follow the installation instructions- [install the FlightGear Flight Simulator (optional)]- have a look at the sketches (examples) and browse the api documentation that is included in the jar fileA very basic example- connects to the flight simulator- displays the current altitude and airspeed

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The UAVsim example- controls the flight simulator via virtual joysticks or...- controls the flight simulator via a PID processor (basic autopilot)- displays various data

Additional examplesUAV Playground - NMEA to KMLUAV Playground 1.1- New GPS NMEA data import via a network connection to FlightGear- New GPS tracking in Google Earth via a HTTP connection to the UAV Playground

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UAV Playground 1.2 [Update] (download)- Completely rewritten autopilot now supports waypoint navigation
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Solar Falcon first attempt with ArduPilot and Nunchuck Acc

Posted by dincer hepguler on May 1, 2009 at 5:30am

my first ground test with APv1 was full of problems. till last summer i am working on my hand made airframe. finished the plane and solar wing is connected and tested. system works well, i tested it for 55mins until my radio battery drained.system: 35 mhz 6 ch radio (because im planning to use 900mhz x-bees for telemetry and 2.4ghz video downlink), solar wing with ailerons, planned to use APv1 on throttle and rudder. stabilization on ailerons and elevator with a hand made system consisting of a Nunchuck accelerometer connected to another Arduino clone and a working software adapted from the work of Andrea Salvatore. first attempt with a Diecimila which worked well but clumsy and heavy. next try was with a Funnel IO which is very small but connections too weak, especially battery connector disconnects often. last try was with an old Ardupilot BetaV3 board used as an Arduino clone which proved as the best alternative.Apv1 connected, throttle on input1 rudder on input2 ctrl on ch5. APv1 software uploaded flawlessly by Arduino IDE.when ESC connected everything looks fine. power led is on, Mux led is ok when engaged via ch5, rudder moves when toggled, GPS lock led is solid within seconds.problem issues:1- when AP is engaged via ch5 rudder moves and throttle is on for a few turns and then spinner stops. when disengaged, problem persists, spinner stops after few turns although stick at full throttle position... possible cause: not enough power for brushless motor?.. although the solar panels are connected to support battery with 1.2Amps... not a problem when AP board was not in the system...2- loss of signal simulated by shutting off the radio. Mux led and status led is blinking. AP moves rudder and tries to apply some throttle, spinner is on for a few turns and stops. the elevator moves down immediately (that is weird because it is not connected to AP)... possible cause: rf intervention to receiver which has lost signal... thank god the plane is not in the air...any suggestions and help will be appreciated... i can provide some pics and video...
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Developer

ArduPilot: New Attiny FailSafe Firmware V1.6, now with RTL in case of R/C signal loss (Beta)

Posted by Jordi Muñoz on April 29, 2009 at 5:29pm
The latest ArduPilot Fail Safe firmware V1.6 includes a state of the art system to detected if we have glitches or bad signal, triggering the RTL and avoiding undesired "Remote Resets".How it works?Well, the first part is just a low pass filter that works only when switching to autopilot, this prevent undesired toggles to autopilot mode when the signals becomes "noisy" and also avoiding undesired resets (the system mistakenly thinks you are toggling the switch).The second parts is a "Valid Pulse Width Checker", this is a very simple code that will increment a counter every good pulse received, if the system receive 75 valid frames (by default) it will thrust the commands we send through the remote control, otherwise will trigger RTL, and reinforces the prevention of undesired "Remote Resets" caused by noise.Of course the latest code could be found in the same place as always, here.The Attiny has been tested only on ground with my 72mhz Futaba and two different receivers, after confirmation i will remove the beta tag, and i will try convince Nathan to flash it on the SparkFun boards, in the meantime you can try it with your AVR programmer. ;-)Whats next?Well right now I'm working on the new ArduPilot firmware code name "Hybrid", will support NMEA, SIRF , uBlox UBX and VENUS 10HZ GPS protocols, on the same code, and you can switch between them by just changing a single variable, bad news, only works on 328. =P
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T3

Yet Another Autopilot

Posted by Brian Wolfe on April 26, 2009 at 2:47pm
It seems everyone and their mother has an autopilot board they're working on so I thought I would join the bandwagon. I've actually been wanting to develop one for quite some time, but after seeing Bill and Paul's progress on their DCM estimation work I got inspired to get started now.There are several good autopilot boards available for experimentation, but none that had the feature set I was looking for. I wanted something versatile enough to be used in several controller/data logging applications including those involving RC cars/boats/copters/planes as well as high altitude ballooning and rocketry. With this versatility comes a little more complexity, so this might not be the board for someone just starting out, but for others I hope it will be a good platform to work with.Here are a few specs/features.Pic32 based -> An inexpensive chip ($8 or less) with respectable horsepower (32 bit 120 DMIPS) and free development tools. An inexpensive programmer can be had from Sparkfun and others.Micro SD Card based Data logging-> Lots for storage for logging every aspect of your flight. Can also be used to read way points or other mission data.USB Interface -> Useful for uploading/downloading mission data, payload control and as a bootloader for program updates.Real Time Clock -> Time tag logged data or perform time based mission functions.5 PWM Inputs and 5 PWM Outputs -> Interface to existing RC Rx outputs and drive up to 5 standard RC servos.On Board 3 Axis Accelerometer -> 12 bit resolution + Software control of sensitivity (1.5G, 2G, 4G, 6G).On Board 3 Axis Gyro-> 12 bit resolution + Software control of sensitivity (110 deg/sec or 500 deg/sec). family of pin compatible gyros from 67deg/sec to 2000 deg/sec.On Board 3 Axis Magnetometer.GPS Interface -> UART based interface with option of 5V or 3.3V power.Radio Modem Interface -> UART based interface with option of 5V or 3.3V power.Battery Voltage and Current Monitoring. Up to 24 Volts and 50 Amps.On Board 3.3V and 5V regulation -> Plenty of current capability to handle heavy servo loads and RF Modem power requirements.Lots of digital and analog IO -> IR and Sonar based range finder interfaces. Airspeed and Altitude interface. I2C, 8 bit data bus + discrete digital IO.This design will be completely open source, and below you will find a link to the preliminary schematic. I will start on the layout next and hope to have it completed and ready to send in for fabrication on May 4. I look forward to comments/suggestion on the schematic. Also if anyone is interested in getting one of the prototype PC boards when I have them made please let me know. Bare in mind however that this is a prototype and I can make no guarantees that there won't be some boo boos. The parts are small and surface mount, so if your not an experienced assembler you might want to take this into consideration.Although not always the cheapest, I have always had good luck with Advanced Circuits for PC Board fabrication. The cost for 1 week turnaround is $66.00 per board (4 layers) +shipping.I'll post a complete parts list in a week or so when I finish the layout.Software development will follow. I plan on quickly implementing a shell to handle all the timing and IO interfaces, followed by a gradual implementation of the various controller tasks hopefully with community support.Looking forward to comments.Regards,Brianpic32_autopilot_schematic.pdf
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3D Robotics

Settings you can change in the ArduPilot 2.1 code

Posted by Chris Anderson on April 26, 2009 at 9:00am
In addition to the setting you can change from the desktop utility program (rudder and elevator trim, max speed, waypoints and home postition), these are the settings you can change from within the code itself. They're all at the top of the first tab of the code (called "ArduPilot_EasyStar_WP_PRO). My annotations and instructions are in [brackets]: Especially note the settings at the bottom that allow you to reverse servo travel and say whether your FMA sensor is pointed forwards or backwards: [maximum servo throw in each direction] #define servo_max 2000 //For servos pitch and roll #define servo_min 900 [PID gains for navigation: In general when tweaking PID gains to reduce quick oscillations you must decrease the P, to reduce long oscillations also reduce I, the derivative is to slow down oscillations but is not implement due to the lack of refresh rate.] #define head_P 1.2 //.7 Heading error proportional (same used to move the rudder)... #define head_I 1.5 //heading error integrator Not used for navgiation #define head_error_max 35 //The maximun output in degrees to control the roll setpoint #define head_error_min -35 //The min output in degrees to control the roll setpoint [PID gains for roll stabilization. Same as above #define roll_abs .3 //Set point absolute proportional... I don't know how to explain it... #define roll_P .8 //roll PID proportional #define roll_I 1.3 //roll PID integrator #define roll_min -45 //55 //PID output limit in servo degrees #define roll_max 45 //PID output limit in servo degrees #define roll_comp 0 #define roll_Integrator_max 35 #define roll_Integrator_min -35 [PID gains for altitude control. Same as above] #define alt_P 2 //proportional to control the altitude hold... #define alt_error_max 0 //The maximun output in degrees to control the pitch setpoint #define alt_error_min -10 //The min output in degrees to control the pitch setpoint #define throttle_max 1800 //In us seconds #define throttle_min 1200 #define throttle_dead_zone 20 //In porcent #define throttle_absolute 3 #define throttle_kp 2 #define throttle_ki 1 #define throttle_max 80 #define throttle_Integrator_max 50 #define AirSpeed_Central 25 [PID gains for pitch control] #define pitch_P .9 #define pitch_I 1.5 #define pitch_min -50 #define pitch_max 50 #define pitch_Integrator_max 25 #define pitch_Integrator_min -25 #define PID_dt 20 //Servo refresh time in milliseconds [Says whether a Z sensor is present or not. [Note: autopilot will not properly calibrate without one] #define SENSOR_Z 1 [Says whether the FMA sensor is pointed forward or backwards] #define REVERSE_X_SENSOR 1 //1 = cable behind, 0 = cable front [If your servos are reversed set these to 1 instead] #define REVERSE_ROLL 0 //To reverse servo roll #define REVERSE_PITCH 0 //To reverse servo pitch
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First flight on auto pilot!

Posted by Jonas on April 26, 2009 at 7:30am
Oke today was a big day I had my first flight on autopilot. (I did not fly exualy)Here are the setup and results:ardupilot 2.1 with z sensor. plane little cessna (see my pics).First I did a field setup to set up the home position. Pilot Marijn Penninx (he builds really great planes, check out www.scale-jets.com) took off and went to a safe alt. So he switched on the auto mode (RTL) and in one sec or less my plane was upside down. Something I did expect because I have noticed that the ir xy is doing the opposite so he got the plane back on the ground and we turned the fma xy 180 degrees (cable facing foreward). Plane back in the air. Safe Alt an auto (RTL) on, now it's responding as it should be. But it wobbles, the elevator is correcting too much. I have seen a little video on this site and they had the same problem (over correcting).I need to alter the code so the elevation is less extreem. When I hold the plane in my hand and point the nose of the plane a bit down, I get full elevation. Where can I adjust this? And are there more settings I need to adjust to get more stability. I have tried to adjust some trim settings but then the plane started to spin down.Pilot Marijn said to me that he uses not more then 10 % of stick to controll the plane.Today's conclusion:- Need to understand why do I need to place the IR XY backwards (cable facing to the front);- Need to fine tune elevation output on auto.Suggestions and solutions are welcome...ThankxJonas
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3D Robotics

Correction on ArduPilot 2.1 field setup procedures

Posted by Chris Anderson on April 25, 2009 at 10:27pm
We got mixed up on versions and said the way to set up ArduPilot 2.1 at the field to record the home GPS position and switch the GPS module to digital mode was to connect ground and pin D6. Actually, the correct method is to put a jumper over pins D6 and D7, just like ArduPilot 2.0. Apologies for the confusion (we're working with too many code versions, and the ones using the shields we now have in prototype will have a more graceful setup procedure).
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Ardunio Mega code to read MicroMag 3-Axis Magnetometer

Posted by MC on April 25, 2009 at 11:23am
We can calculate the UAV heading (flight directions) from multiple consecutive GPS readings if the UAV is moving. However, for a hovering, this method would not work and we may need a magnetic compass or a magnetometer (like MicroMag 3-Axis Magnetometer from SparkFun).Is there any code out there for Ardunio Mega to read 3D magnetic vector using MicroMag 3-Axis Magnetometer ?
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T3

MatrixNav revision 2 is released

Posted by William Premerlani on April 25, 2009 at 10:42am
Revision 2 of MatrixNav firmware has been flight tested and is now released. The documentation and operation stays the same as for the previous version. The link on the main page for the UAV DevBoard points to the new version. The documentation is available there, also.The baud rate for the binary serial interface to the GPS has been raised in this version from 4,800 to 19,200. This eliminates a 12 second delay in the GPS information that was present in the previous version. As a result, performance in windy conditions has been improved.If you are using the previous version of MatrixNav, replace it with this version. If you made any changes to the control gains in the file controlGains.h, be sure to either save your existing file, or record the values that you are using, and edit the controlGains.h file that is part of the new firmware.The YAWKP and YAWKD gains in the new version have been lowered from the previous version by a fair amount, so that the turns are wider and smoother. In the previous version, a switch to RTL mode would result in your plane "turning on dime". In one of the comments below, Sid recommends lowering the gains. Just so there is no confusion, you should understand that they have been lowered.Also, in the previous version of MatrixNav, YAWKP and YAWKD were postive. In this version they inadvertently wound up to be negative. So if your plane is already set up with the previous version, either make YAWKP and YAWKD positive, or toggle the position of switch SR1 on your board.Bill Premerlani
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Developer

Ardupilot Utility Beta 3 Released Now Supports Atmega328!

Posted by Jordi Muñoz on April 24, 2009 at 5:00pm
Finally! took me some time fix this. But for some reason the new bootloader of the Atmega328 is running at 57600bps (Hoo! that means the uploading time is a lot shorter compared with AT168), so i had to add the option to select between atmega168 and atmega328 as is illustrated in the picture above or right.Of course the latest file can be found here.Please report bugs, is normal that the upload/downloading procedure fails sometimes, but not so often...In the near future, the app will include:-Save and Load missions from the hard-drive (do you like .adp as extension?).-A better way to add waypoints.-Choose the desired speed for each mission.-And many more...Enjoy!
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Developer

ArduPilot Shield Demo

Posted by Jordi Muñoz on April 23, 2009 at 12:30pm
I few days ago i received the first prototypes of the Ardupilot Shield. Right now they don't have silkscreen to reduce the prototyping costs, but the commercial version will do..Main goals:-On board 3.3V power regulator.-Disable the GPS before uploading new firmware automatically.-A lot of pins headers to easily attach sensors with power supply included.-Special connector for 3.3V GPS modules (including the TTL conversion).-Pressure sensor, with low pass filtering, for AirSpeed...-External reset button.-Mirrored status LED,s...-Optional power divider (analog 5) to measure battery level.

[Infrared connector at the bottom]The cost without the sensor will be around $20 dlls at beginning, soon if i order bigger batch's i can reduce the price.My ideas is to make 100 units without the pressure sensor, and another 100's with the pressure sensor (around $30 dlls price tag)... Stay tuned for more news..You can give a look to the diagram here:

[UPDATE]: Auto turnoff is not working properly on 3.3Volts GPS, so i will need to make some changes.
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T3

EM406 dynamics: final resolution

Posted by William Premerlani on April 22, 2009 at 4:35am
I have the issue of the latency in the dynamic response of the EM406 GPS in binary mode finally resolved: you have to run at 57,600 baud in binary mode. Apparently there is a large communications buffer in the EM406 that gets flushed by the carriage return/line feeds in NMEA mode, but which does not get flushed in binary mode, unless you run at 57,600 baud. There must have been a memo on this, but I missed it.I will revise the MatrixNav code and release it as soon as I can give it a test flight. The drop in latency from 12 seconds to a few seconds should vastly improve the performance in windy conditions.Thank you all for your help, especially Chris Anderson, Jack Crossfire, and automatik.I should have listened to you, Jack. Next time I will.By the way, the EM-406A performs very well with respect to sensitivity and fast response. Now that I have resolved the binary interface issue, it performs as well as any of the other GPS radios that I tested. I plan to continue using it in future designs. There really is no point to using GPS units with reporting rates that are faster than 1 Hz. As far as I can tell, all they do is interpolate.Bill Premerlani
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Two questions about getting started (FMA sensor, IMU)

Posted by Garry Qualls on April 21, 2009 at 11:55pm
Now that the Ardupilots are back in stock, I am ordering what I need to get one up in the air. The FMA IR sensor is out of stock at FMA Direct until May 15, so does anyone know of another vendor that may have them or if there is an easy replacement I could order or build? It's just three weeks, but I am anxious to get started ;)Question 2, I would like to put a decent IMU onboard to document the vehicle attitude in flight. The three options I've found at SparkFun are the IMU 6DOF - v4, the Atomic IMU 6DOF, and the UAV DevBoard. The "v4" is the only one with magnetometers, so one could expect it to be more accurate at the end of a 30 minute flight, but I've seen similar systems where the magnetometer readings were so noisy that they were useless. Down the road, I might want to use the IMU I purchase to drive a motion compensation system. Has anyone used one of these? All three are within my price range. My main concerns are accuracy and ease of integration. So, does one have a clear advantage? Are there other IMUs on the market that I should consider?
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