Blogs

All Posts (14036)

Sort by

Its been 8 months since my last post and i'm back to UAVs again. this time i have project funding, so money will not be as big of a project halter as it was with the last one. I am still learning Sta

Posted by Genesis Factor on June 21, 2008 at 12:02am
Its been 8 months since my last post and i'm back to UAVs again. this time i have project funding, so money will not be as big of a project halter as it was with the last one.I am still learning Stamp BASIC programming. I've spent my time learning to fly the heli though. I intend to use a propellor board as my heli's main processor. However, the Prop board leaves a lot lacking. I am into SBCs and big computer calculations, not these microprocessor mini codes. Therefore, when i won a nice Boser HS-2605, i suddenly realized i had the best of both words- low power consumption (16W) and lots power to crunch (667mhz Via Eden processor;256MB Ram; CF slot for expansion; HDD) and lots of things for adding on (PC104 and USB1.1). Therefore, i'm putting the Heli on low priority as i don't trust my programming ability in BASIC.My Primary airframe is the NitroModels predator. My secondary is the Eflite UltraStick 25e. HTe reason for their designations is due to the wing loading. by adding 2.8lbs on top of the advertised flying weight (which includes beefed up engines and batteries) i've calculated that the wing loading with be 22.868 oz/ft^2 and 28. something (i forgot) respectively.I will be reinforcing both models along the fuselage and and the wings.Proposed features-modular computing coredual camera set up, 1 FPV, 1 panoramic scanning with motorized zoom and focus.GPSAltimeterLeveling (FMA CPD4 based system)long range (~1000ft-2km) up and down link via ground station (hopefully)Emergency parachuteThe UAV part will be switched on at certain times in order for the operator to use the scanning camera more efficiently with minimal distractions. It also will allow the operator to plan a survey by using mappable way points (later in the project).We will see what will happen as time goes on.Right now, the main objective is to get this thing to see, fly, and know its own position. :) One step at a time.
Read more…
3D Robotics

How can we make IR beacons with unique IDs for Blimpduino?

Posted by Chris Anderson on June 20, 2008 at 10:30am
Jordi and I are slightly stuck at the last part of our Blimpduino project. We've got the blimp itself all sorted, from electronics to mechanical assembly, and are ready to move into mass production on that. We intend to ship it with a single ground-based IR beacon, around which it can navigate, and that's done, too. But ultimately, we want it to be able to navigate to multiple beacons, and that's where we've run into a problem. Let me describe the issue, and maybe some of you will have some ideas.

To keep Blimpduino as cheap and simple as possible, it navigates by looking for signals from a ground-based IR beacons in any one of four directions. There are four IR detectors (N,S,E,W) on the blimp and the ground-based beacons are nothing more than an IR LED transmitting random 1s and 0s at 56KHZ. This being IR, they bounce all over the room and there is loads of IR noise from other sources, but the IR receiver that records the highest number of 1s (highest signal-to-noise ratio) is considered the direction that the beacon is transmitting directly from and we steer accordingly. (This is also the way the Pololu IR beacon/transceiver pairs work)

That's easy for one beacon. But when we want to introduce multiple beacons, each with a unique ID, it gets more complicated. We can't transmit at different light frequencies, because we'd need to add matching IR receivers on the blimp for each beacon we added. We can't use TV remote control codes, because then we can't tell where they're coming from (it's the ratio of signal to noise that tells us direction, but the codes are all signal and work as well if they're bouncing off a wall as when they're aimed directly).

Our instinct is to have a central beacon controller (another Arduino--see diagram above) and sequence them so that you'd be able to tell which beacon is transmitting by when in the beacon sequence you got the signal. But that requires us to synchronize the blimp and the beacons to a common clock, and we're debating how to do that.

My proposal is to do the following, 10 times a second:

  1. For the first 1-50ms in each cycle: all beacons go on for 30ms, then all off for 20ms ("clock sync pulse").
  2. 50-60ms: Beacon 1 on
  3. 60-70ms: Beacon 2 on
  4. 70-80ms: Beacon 3 on
  5. 80-90ms: Beacon 4 on
  6. 90-100ms: Beacon 5 on
  7. Repeat...

The beacon hub controller would just schedule that sequence. The blimp, meanwhile, would have to detect both the direction of signals and how long they're on. If they're on for 30ms and then off for 20ms, that's the start of a cycle. Then depending on when in the cycle it detects the next signals, it knows which beacon that is.

Jordi's not convinced this will work, and thinks we'll need an RF link to communicate between blimp and beacons, which strikes me as expensive, complicated and unnecessary. What do you guys think?

Is there a better way to have a blimp distinguish between different IR beacons?

Read more…

Colored diagrams of Icarus

Posted by Jake Lancaster on June 17, 2008 at 10:22am
Maybe this will help with the visualization processRed = propellersBlue = Electric motorsYellow = Flight surfacesGold = Flight control surfacesLight Gray = Helium EnvelopeDark Gray = Cradle, Electronics houseing, and HullGreen = CamerasTop View

Front View

Side View

Read more…

best way to read a servo signal on arduino

Posted by quix-fz on June 17, 2008 at 6:20am
the atmega168 on the arduino has a timer1 which has input capture capability (see this application note and datasheet for atmega168 for details). using it, it's possible to do the pulse timing in completly in hardware (no errors, no jitter), and having a interupt readout the measured time.here's the code:unsigned int serinp[8]; //servo positionsvoid setup_timer1(){//disable all interuptsTIMSK1 &= ~( _BV(TOIE1) | _BV(ICIE1) | _BV(OCIE1A) | _BV(OCIE1B));//set timer modeTCCR1A &= ~( _BV(WGM11) | _BV(WGM10) );TCCR1B &= ~( _BV(WGM12) | _BV(WGM13) | _BV(ICNC1));//capture raising edgeTCCR1B |= _BV(ICES1); //capture raising edge//prescaler 1/8TCCR1B |= _BV(CS11);TCCR1B &= ~( _BV(CS12) | _BV(CS10) );//disable outputsTCCR1A &= ~( _BV(COM1A0) | _BV(COM1A1) | _BV(COM1B0) | _BV(COM1B1));//enable capture interuptTIMSK1 |= (1<<ICIE1);}ISR(TIMER1_CAPT_vect){static unsigned int lasticr; //icr at last caputrestatic unsigned char cserinp; //current input servounsigned int licr;//TCCR1B ^= _BV(ICES1);licr=ICR1-lasticr;lasticr=ICR1;if(licr>5000){ //pulse too long, means start of new framecserinp=0;}else if(licr>1000){ //pulse good, take reading, go to next channelserinp[cserinp]=licr;if(cserinp<8){cserinp++;}}else{//too short, nothing to see here}}void setup()pinMode( 8, INPUT ); //sumsetup_timer1();}void loop(){//use serinp!!!}it'll take a sum signal on pin 8. you can also connect the signal for a single servo, then just serinp[0] will be populated. the values in serinp are 2 times the microseconds, so between 2000-4000 (instead of 1000-2000), yes, there's extra accuracy in there!the timer-capture only works on digital pin 8!if you don't have access to the sum signal, a possible way to read multiple servos would be to connect them all to pin 8. since the receivers usually output the pulses one after the other, this should work (you'll have to adjust the code in the capture-interupt).
Read more…

Icarus designs

Posted by Jake Lancaster on June 16, 2008 at 9:50pm
Top View

Front View

Side View

To lamely quote a James Bond movie, "I give you Icarus." The main body is 13 feet long, 4 feet wide, and 2 feet high. (not including flight control surfaces, propellers, and cameras). The overal shap is an elongated circle cylinder. The helium envelope provides a total lift of a feather over 3 pounds. I plan on this being somewhere near 85-95% of lift needed. The remaining being generated by the 4 verticle thrust propellers. They also provide more thrust than needed allowing for verticle flight. The 2 propellers on the wings are used more for flight control than speed, while the main propeller in the rear provides the main foward thrust. These 3 propellers can reverse their thrust for further control.
Read more…

simple VTOL airplane with vectored thrust

Posted by Howard Gordon on June 16, 2008 at 10:00am
I just ran across this on Yann LeCun's blog - Yann is a professor of mathematics at NYU, a leading authority on neural networks, and an R/C enthusiast.This is a conventional airframe with two sets of vectored motors (similar to what we're doing with the blimps). Yann reports that two rotors turn clockwise and two counter-clockwise on a diagonal. Stabilization and control is accomplished with a combination of conventional gyros and channel mixing.
Read more…

Icarus

Posted by Jake Lancaster on June 15, 2008 at 7:30pm
HiWell, this post is about a pet project i've been cooking up in my head for the past few months, but have lacked the tech knowledge on how to go about it much more than a few diagrams on the computer and my own imagination. What i've been wanting to build is a hybrid of a semi-rigid blimp and helicopter, with a long length of flight time, good manueveribility, but with speed similar to a RC plane. My first idea was a blimp with their long flight times since very little power is needed to keep them airborn, but looking at the profiles of said types of crafts, their teardrop shape keeps them from attaining the speed i desired. I then thought of a craft with a lower profile so to attain speed, but when done, you lose lift from the loss of space for helium gas. To counter-act that problem, i devised adding 4 verticle lift propellers. Two in the front, and two in the back. This also helps solve the problem of keeping the craft on the ground when not desired to be airborn. Next, foward thrust. I figured on three engines, all reversible. One main prop in the rear and 2 auxillery on wings located halfway on the sides the craft. The wings are for flight control, in addition to other normal flight control surfaces found on planes. The flight electronics, batteries, coms systems will be located in the traditional gondola posistion. Lastly, i decided on giving my vehicle sight, with several cameras. One pointing verticly up, one foward, one behind, and on underneath that can pan and tilt, so it move to see 360 degrees around by 90 degrees up and down. Also, i was wanting the craft to have as long of a control-able range as possible, while being able to still fly and return, if reception is lost, on its own.What i need help with is the electronics. This is not a project i plan on finishing for a long time, but i just lack the knowledge to do this with out help. If anyone knows how i might proceed, please, comment and let me know.
Read more…

A beginners code for autopilot: simple PID and sensor inputs

Posted by Geetesh Dubey on June 15, 2008 at 10:27am

I am trying to develop an autopilot code in bascom for AVR Atmega16...if any one has any suggestions about how to start and the parameters that i need to keep in mind while developing the code may plz blog in with some easy snippet codes if possible...any type algorithm required are all invited... there is gonna be a code each for a FIXED WING and a QUADROCOPTER...thats the COAX heli i built for this years MAV-08 competition held in INDIA..
Read more…
3D Robotics

ArduPilot: New Thermopile Boards!

Posted by Chris Anderson on June 13, 2008 at 10:00pm

Those of you following along with the ArduPilot development probably suspected that we weren't going to stick with leaving the stabilization function to the off-the-shelf FMA Co-Pilot for long. And sure enough, integrating those thermopile sensors into our autopilot has always been part of the plan--it's cheaper, better and more flexible. But how can we handle both stabilization and navigation with the modest Arduino chip? Well, you're just going to have to wait and see--trust me, it's cool ;-) In the meantime, here's the hardware Jordi designed to build your own two-axis thermopile sensor, in surface mount (SMD) form, which is small and light (shown above), or through-hole, which is easier to solder, shown below. It's related to the Paparazzi sensors, but optimized for Arduino. They will not work with the current ArduPilot, which is designed to work with the FMA Co-Pilot, but instead are designed for a future ArduPilot board. So why are we showing them to you now? Just because they're cool, and if you build them now we'll give you a reason to use them soon enough. Warning: the individual thermopile sensors (this board needs 4) aren't cheap at low volume: almost $18 each. At the volume we're buying (100s) they fall in price to just $6 each, so unless you're keen to get going quickly on this you might as well save some money and wait for us to build the boards and sell them assembled. But for those fully infected with the DIY spirit, the component list is below. Code and other integration instructions coming later. Through-hole version:

Components:

C1,C2,C3,C4,C6 5 x .027uF P4518-ND
C5 0.01uF 1 x 495-1065-1-ND
IC1 1 x AD8552RU AD8552ARUZ-ND
MOLEX PRT-08231 SparkFun
R1,R4 2 x 200 200EBK-ND
R2,R5 2 x 0.8M 820KEBK-ND
R3,R6 2 x 510 510EBK-ND
R7,R8 2 x 604 620EBK-ND
(TP1,2,3,4) 4 x MLX90247-ESF-DSA

SMD version (shown at top):

Components:

C1,C2,C3,C4,C6 5 x .027uF PCC1833CT-ND
C5 0.01uF 1 x 478-1383-1-ND
IC1 1 x AD8552RU AD8552ARUZ-ND
MOLEX PRT-08231 SparkFun
R1,R4 2 x 200 P200ACT-ND
R2,R5 2 x 0.8M P806KCCT-ND
R3,R6 2 x 510 P510ZCT-ND
R7,R8 2 x 604 RHM604CCT-ND
(TP1,2,3,4) 4 x MLX90247-ESF-DSA

Read more…
3D Robotics

New version of FMA Co-Pilot system coming

Posted by Chris Anderson on June 13, 2008 at 7:28am
FMA just announced that a new version of their FS8 flight stabilization system (this is the thermopile-based Co-Pilot integrated into a RC receiver) is coming in the fall. No details on what will be different about the new version. In the meantime, you can buy the old version (FS8CPI) while supplies last for $149.95. Call the FMA Sales line at 800-343-2934 (phone orders only). Picture of the old one follows:

Read more…
100KM

How to get a COA

Posted by crystal garris on June 12, 2008 at 4:39pm
well the best way is to find a university interested in uav research , and make your self available to do demos, you usually have to foot the bill yourself but its a great foot in the door. also call your local government services . the trick is to get in with a major university or a governmental agency . after that its really between them and the FAA .but one thing everyone has to understand is that this is serious stuff , our A-3 retails for $75,000 . every time i fly i understand that peoples lives are on the line . this type of job is not for everyone , it is very high stress and mistakes cant be made . just to give an idea about what it takes , we have spent well over $250,000 over the past 2 years and we are just now starting to get some income . so if you have an extra $ 1/4 mil sitting around , can do without if for a few years and are willing to risk it all in what amounts to an overblown r/c monster of an airplane with a 3/4 second control delay this just might be your line of work.so to sum up#1 lots of $#2 fly huge , very expensive airplane or even a small , very expensive airplane#3 get some form of government help (dont be afraid to crack open a phone book and look at the blue pages and call people !! )#4 i have found that most government agencies want big payloads , high altitudes and all weather beyond-horizon abilitygood luck to everone and above allHAVE FUN !!!wayne
Read more…
3D Robotics

DIY Drones in the San Diego Union Tribune

Posted by Chris Anderson on June 11, 2008 at 6:30pm
A big story today in San Diego's newspaper about DIY Drones at the AUVSI conference. Excerpt follows: "'Do-it-yourself drones' create buzz at S.D. convention The unmanned Predator aircraft developed in San Diego during the mid-1990s has become a workhorse surveillance plane for U.S. military forces in Iraq, as well as a robotic hunter-killer. During one 11-month period in Iraq, a squadron of Predators operated remotely by the Air Force flew 2,073 combat missions and fired 59 Hellfire missiles at ground targets. Yet the technology underlying the sophisticated unmanned aircraft is now so easily available and inexpensive that one of Silicon Valley's most influential figures is encouraging hobbyists to build and fly their own. Chris Anderson, the editor in chief of Wired magazine, stepped forward as an evangelist for such “do-it-yourself drones” yesterday at a conference for the unmanned systems industry at the San Diego Convention Center. “This kind of technology, which used to cost millions of dollars, then hundreds of thousands and then thousands, now costs hundreds of dollars,” Anderson said. As the founder of DIY Drones, or Do It Yourself Drones, a Web site for hobbyists and others, Anderson is showing just how easy it is to use off-the-shelf components to build unmanned aircraft for the masses...." Lots more here.
Read more…
3D Robotics

RoboGames this weekend in San Francisco

Posted by Chris Anderson on June 11, 2008 at 7:41am
This weekend RoboGames returns to the Bay Area. It describes itself this way:

"RoboGames is the world's largest open robot competition (even the Guinness Book of World Records says so!) We invite the best minds from around the world to compete in over 70 different events. Combat robots, walking humanoids, soccer bots, sumo bots, and even androids that do kung-fu. Some robots are autonomous, some are remote controlled - but they're all cool! As an open event, anyone can compete - this means you. "

No UAVs (that I know of) but I might be there on Sunday with the kids to check out the battlebots. PM if you're coming and perhaps we can meet up.

Read more…
3D Robotics

Five things I learned at AUVSI today

Posted by Chris Anderson on June 10, 2008 at 10:30pm
Wandering the amazing show floor at AUVSI in San Diego and talking to engineers there today with Jordi (shown), I learned a ton. Here are five things that maybe everyone else in the world knew, but I didn't: 1) "Primary" (non-rechargeable) batteries have twice the energy density of rechargeable Li-Pos. So look again at those little 3v lithium camera batteries for your blimp! 2) A fuel cell + Li-Po combination also has twice the energy density of Li-Pos alone. The fuel cell can't delivery current fast enough to drive a motor, but it can charge the battery, which drives the motor. The combo isn't small, but it is efficient--you can get hours of flight time for a powered glider. The energy density still isn't as high as gas alone, but it allows you to use electric motors, which are quiet and clean. 3) For some reason, you can put a barometric pressure sensor input tube directly in the prop stream and it will only throw off the pressure reading by a few meters. That's bizarre, but good news for those who don't want to pipe those tubes way out to the wingtips. 4) Cheap and small differential pressure sensors can measure speed and altitude simultaneously. (One goes to a pitot tube, the other measures ambient pressure.) Also, it sometimes makes more sense to put the sensors on a daughterboard and put it out on the wing with a long wire back to the autopilot (like we do with our GPS sensors), than to bring the air to the sensors on the autopilot board with long tubes. Tubes are more likely to fail than wires. 5) Using mil spec connectors in your UAV can add more than a thousand dollars to the cost for no functionality gain whatsoever.
Read more…
3D Robotics

New BlimpDuino board, now surface mount and RC compatible

Posted by Chris Anderson on June 9, 2008 at 7:30pm

The DIY Drones autopilot board factory is in full swing. We've got another cool board for you, a production-ready final version of the BlimpDuino board.

Changes include:

  • All surface mount technology, to make the board smaller, lighter and easier to manufacture.
  • Now with two dedicated RC channel input ports, so you can easily fly in RC mode (for testing) or autonomous mode.
  • A new power supply that can handle anything from 3V to 18v and output both 3.3v and 5v. This will allow you a range of battery options, from 2 or 4 AAAs (cheap) to a 7.4v Li-Po (expensive).
  • Includes a port for a servo, for the vectoring thruster
  • Includes ports for a Bluetooth wireless module and a magnetometer (compass)

The board is designed to fit in and work with both a modded toy RC blimp or a custom blimp gondola.

You can buy the board here.

Eagle 5 files are here: blimp_SMD_V4.sch blimp_SMD_V4.brd

Here are the components that you need:

SMD DIGIKEY parts:

Capacitors:
(C4)2x 22uF 495-1556-1-ND
(C1,2,6,7,9,10,11,12,13)9x 0.1uF PCC1828CT-ND
(C8) 1x 33uF 478-1715-1-ND
Diodes:
(D4,D5,D6,D7):4x Navi LED (green) 67-1357-1-ND
(D2):1x Power LED (red) 67-1359-1-ND
(D3) 1x Status LED (blue) 160-1643-1-ND
IC's:
(IC1)1 x Atmega168, ATMEGA168V-10AU-ND
(IC2) 1xLM3940: LM3940IMP-3.3CT-ND
(IC3) 1xL4049: 497-1404-5-ND

Resistors:
(R1) 1x 10kOhms P10.0KCCT-ND
(R2) 2x 1Kohms P1.00KCCT-ND
(R3-R7) 4x 30 ohms P30ACT-ND


3x LB1630 (motor controller).
4x IR sensors (Pololu)

Switch:
(S1) Switch SMD, sparkfun
A lot of pin headers

Arduino code coming soon

Read more…