Early customers are starting to receive their Naza GPS Units, and while I await mine, the early feedback appears positive.

DJI customers in the southern hemisphere will be pleased to hear there are as of yet no reported issues regarding GPS lock. The GPS Upgrade, which brings Position Hold, Return to Home and Simple mode (often known as Carefree mode) appears to be around the $190 tag for existing customers.

I thought I would share a couple of photos of the quick connector I soldered on to my arducopter Sonar which incorporates the power filter I posted a while ago (Link).   I started experimenting with different sonars from MaxBotix and wanted a way to incorporate the passive filter and connector together.  Over time having everything wired up including the resistor in the +5v line seemed to eventually break with the cable moving / being unplugged from the APM.  If you look closely you can see I have the 10 ohm resistor going into the +5v on the Sonar board and the other end connects to the appropriate edge connector pin.  I find this setup very reliable when swapping out parts for testing.

Here are some other photos:

The above photo shows the 100uF Electrolytic mounted across the +5v and gnd.

It was fun day :) We shot review of new Ferrari California that now on the market in Israel, (video is in Hebrew).

There is few shots from my tri-copter, also at 2:34 tri-copter got in to the shot :)

Some photos from the set:

Tri-Copter:

APM 2.0

Motor Mounts - jD Multi Mount

Motors - T-Motor MS2212 980KV

ESC - jDrones ESC 30 Amp 

GoPro mount - ArduCopter GoPro Cameramount, 2 axis 

Driver Leon Taoubes

Big thanks to Ferrari Israel for letting us play with $500K toy :)

Western Australia.  A mini tornado ripped through a the Perth suburb of Dianella today.  With all the streets blocked off by the Police, power poles and trees uprooted, the media contacted COPTERCAM to fly in and take photos and videos of the area.

More photos here:

http://www.flickr.com/photos/coptercam/sets/72157630071544992/with/7162430283/

Just small manned planes for now. Key quote:

"Asked if Google had any plans to use unmanned aerial drones to gather photos for its 3D cityscapes, McClendon said it was an interesting question, but noted that drones were still being evaluated by the Federal Aviation Administration.

“That’s a larger can of worms that we’re not going to get into here,” he said."

(via @drones)

From IEEE Spectrum:

One of the ways in which robots are just starting to get really useful is with hauling aerial cargo. Last year, the optionally-manned KMAX made its first autonomous cargo delivery in Afghanistan, and since it can fly as many missions as you have fuel to keep it going, it's definitely a safer and more efficient way to get supplies to troops, especially in dangerous areas.

To move cargo around, helicopters (autonomous or otherwise) often carry stuff slung beneath them on long ropes, and as you can probably imagine, said cargo often ends up doing all sorts of swinging about, especially if the helicopter that's carrying it has to maneuver. Researchers from the University of New Mexico have been developing algorithms that allow robots to compensate for motion-induced swinging of suspended loads, and testing them out on real live quadrotors.

Essentially, what the quadrotor is doing here is dynamically adjusting its trajectory to damp out the swinging motion of its cargo (think tacos). It's sort of like an upside-down version of pendulum balancing, with maybe a little bit of this insane hinged stick balancing thrown in for good measure. Next, the researchers plan to see if they can get their algorithms to work on platforms that are less balanced (and more realistic), which (they say) should be "an important step towards developing the next generation of autonomous aerial vehicles."

Trajectory Generation for Swing-Free Maneuvers of a Quadrotor with Suspended Payload: A Dynamic Programming Approach, by Ivana Palunko, Rafael Fierro, and Patricio Cruz from the University of New Mexico, was presented last month at the 2012 IEEE International Conference on Robotics and Automation in St. Paul, Minn.

[ MARHES ]

I built the AC SIm to do gain tuning and now AB testing of various control algorithms. I've made some significant strides in the control loops, so I though I would detail out how it was done.

There is very little code left over from AC 1 in the current code base. When I started AC 2, I used the v1 control loops and assumed they were good. (Everyone was very happy at the time with them.) I also had no real way to measure the performance of them.

A few months ago I started to get very suspicious that the old carryover code was causing a lot of the flight headaches I've been experiencing such as aggressive flight leading to a flip. Or slow, wobbly response in descents. Max was complaining that AC2 lacked "wings". That's not a lot to go on, but it is real feedback that something needed done.

I built the SIM specifically to tackle this type of problem and here is how it was used:

In the SIM a parameter was created called g.test. A checkbox toggles the value of this param and the boolean value is used to turn on or off chunks of code. This gives me a side-by-side comparison of the impact.

Suspect code:

Attitude.pde: get_stabilize_roll() and get_stabilize_pitch();

// limit the error we're feeding to the PID

target_angle            = constrain(target_angle, -2500, 2500);

This line limits the desired rates sent to the rate loop.  A before and after plot shows the performance gain when this line of code is disabled. The Initial state of the copter was roll left at 450° per second. The plot shows the roll angle going to -85°, then recover to 0. Removing that line improve the recovery time from 1.15s to .75s

Suspect code 2:

This is the quad suddenly rotating at 600°/s to the right.

I've increased the roll output limit  in rate_roll and you can see the recovery time to level has decreased  35% to .8 seconds to level from 1.24 seconds. The angle error significantly decreased as well.

 

Patch 3:

There is an iterm in the stabilization code that causes the copter to level out when the CG is off or a motor is out of balance. The problem is the iterm can drift around when flying because drag or a low CG can prevent a copter from holding an steep angle and cause us to be 1-2° off when going back to level. We only want this term to hold level, so I placed a limit on the iterm like this:

if(abs(ahrs.roll_sensor) < 500){

    angle_error  = constrain(angle_error, -500, 500);

    i_stab  = g.pi_stabilize_roll.get_i(angle_error, G_Dt);

}else{

    i_stab  = g.pi_stabilize_roll.get_integrator();

}

Here is the effect plotted on a copter that has a 3° lean to the right. The iterm ramps to 3°, but it moves a lot when flying around.

Here is the patched code:

Notice the iterm ramps up and doesn't really budge. That should really help in keeping the copter still in the air.

 

Patch 4:

Keeping the copter holding altitude while pitching hard was work OK, but not great. The copter tends to drift down. I got that piece of code from a description in Berkeley's STARMAC copter project. 

static int16_t get_angle_boost(int16_t value)

{

    float temp = cos_pitch_x * cos_roll_x;

    temp = 1.0 - constrain(temp, .5, 1.0);

    int16_t output = temp * value;

    return constrain(output, 0, 200);

}

I changed it to this:

static int16_t get_angle_boost()

{

    float temp = cos_pitch_x * cos_roll_x;

    temp = constrain(temp, .5, 1.0);

    return ((float)g.throttle_cruise / temp) - g.throttle_cruise;

}

This has the effect of maintaining perfect downward acceleration at all times. The reason this works is the throttle-cruise (say 500 out of 1000) is = to 9.81m/s/s of downward acceleration. We can use a linear mapping of throttle to acceleration to achieve the additional throttle necessary for the combined roll and pitch tilt.

Bonus 

The last example not is not a patch but a tuning example:

For a basic setup we've been using Rate_P of .14 and Rate_D of 0. Also a Rate dampener similar to the Wii project of .15 Many folks were OK with these gains, but the performance was meh in Max and Marco's experience.

Here is a copter at 45° returning to 0° with the current gains and no patches:

With Patches:

Notice the overshoot and the bell ringing. The frequency with the above with patches is lower and that's good.

Here is the comparison of the above, but with the optimum gains:

These gains are now the default gains:

rate_P of .18

rate_D of .004

stab_D of 0

Please try these gains in the simulator and raise and lower the rate_D term. I was pretty surprised to see how tied the Rate_P and Rate_D are to each other. They cannot be tuned independently. A rate_P of .18 and Rate_D of 0 will not fly well at all. It will fast wobble in the air quite a bit.

I hope this was interesting. The SIM is currently residing at www.jasonshort.com

Jason

I wish I had taken more time to take pictures of the project as it progressed. Unfortunantly I was to busy having fun to stop and think about it.

I purchased a SZD-45 Ogar from a model shop with servos and motor already installed. With a little work (and help) I attached a 20amp ESC, battery and an 8 channel rc setup. Once that was done I took it up for a test flight to see how it flew. Everything worked well so I took it back to the basement to add the APM2. Another couple of test flights, checking functionality and modes, and it was back to the basement to get the camera and telemetry wired up. The camera is mounted to the inside, and by way of servos, drops down through the belly during flight.

From Arduino Blog - BaTboT: a biologically inspired morphing-wing bat robot actuated by SMA-based artificial muscles.

Researchers from Centro de Automática y Robótica (Universidad Politécnica de Madrid) and from Brown University carried out a very deep research about the specific behavior of bat flight, whose ultimate goal is to replicate the capabilities of bat’s wings by means of an ad-hoc designed micro aerial vehicle (MAV).

More details on the site: http://www.disam.upm.es/~jdcolorado/BAT/BaTboT.html

Swiss pilot Bertrand Piccard has been the first person who made the crossing from Europe to Afrika in a solar powered airplane. This was the first time that an airplane of this type made an intercontinental flight.

On Tuesday morning at dawn Piccard (54 y/o) left Madrid. After a 10 hour flight he reached Maroccan airspace with his plane 'Solar Impulse' after crossing the mediteranean sea. Late night he landed his plane in Rabat.

The Solar Impulse has a wingspan of 64 meter, comparable with an Airbus 340. It weighs only 1600 kilo's, about the weight of a luxury car. The wing is covered with solar panels and together with the batteries it can fly day and night.

For more information on the Solar Impulse and the team behind it, go here: solarimpulse.com/

Not too bad for my first edit. Used premier (my first time)

Tried uploading it to vimeo for copyright reasons, but no go.

So I uploaded to you tube. The only country that its blocked in is Germany...

G:)

I found this HD camera on the net today, and it seems to be the perfect alternative to the GoPro, as it is lighter and has a smaller size, which could be important in terms of micro-quads, etc..

Its smaller than the GoPro HD Hero, at 4 inches long and half inches across and weighing in at 4.5 oz, it is a  truly ultralight HD videocam with the added bonus that it looks the part of "Eye in The Sky"

There are outputs for HD video, so just hook it up to a FPV transmitter and you are good to go! MicroSD cards are supported and you can record videos directly, even without an FPV setup. Beneath the bubble-shape front of the camera there is a 170-degree wide-angle lens which can capture video along with 5-megapixel HD stills.

The on-board battery is clamed to be good to upto 4 hours of 1080p recording, and it can be connected via USB to a computer to download the photos or charge the battery.

Another version, with WiFi,is also capable of steaming video to your iDevice/ Android device ,while the iPhone/Android phone,etc. acts as a controller for the camera. (Think PhoneDrone with this camera!!!)

At $230, without any accessories, I think its a pretty good deal as it is extremely light and small, with is infact a big deciding factor for me, as I design micro-quads only.

More details at their website, and be sure to check out the other models as well!!

Air Pro ION

My Bixler is mostly assembled, but there are some odds and ends. I need to secure the ESC inside and figure out a good way to secure the wings.  Mike Pursifull suggested using Command hooks and a rubber band.  Any other ideas for that? 

I've heard complaints complain about inadequate rudder area so I may try to add some with some index cards or something similar (also Mike's idea).  I'd be interested in feedback on what people have used to accomplish this also.

I did lots of ground testing adjusting servos and verifying the correct control orientation.  I think it's all set.

As suggested by a couple folks I removed the nose weights and the control horns with hot water and reglued them with 5 minute epoxy.  I've read some people don't like epoxy on EPO, but my new joints seem pretty solid.

I got failsafe working by holding down throttle cut while binding and verified that it went into Circle immediately and RTL after 20 seconds,

Here's a closeup of the cockpit. You can see the packing tape I put on the bottom and the chinstrap velcro for the electronics chassis, which is an idea I borrowed from Eagle.

Let me know if you have any feedback.

The new Condor Skywalker 1880 is now ready for sale at FPVflying.com.

The Condor skywalker is made out of nice black EPO foam just like the black X8 wing.

The new wing design is made for better performance.

More payload - longer flying time.

Here are some pictures to see the difference between the Skywalker: 168, 1900 and the Condor 1880.

See more about the new Condor Skywalker 1880 UAV platform.

As requested, here is a clip of one of my test flights with the APM2 on my 600. This may be the most boring video ever, but in this case, boring is exciting! The APM2 works amazingly well mounted on Align gel, where a tail gyro normally sits. Stabilization is very good using  these parameters, though I need to lower the yaw values since there's still just a bit of tail wagging.

I've had this bird for a couple years, so unfortunately I think there is a bit of play in the linkages, and a couple of the servos have sticky spots. This causes small variations in the rotor disc (leading to slight wandering) which the APM is not responsible for.

The previous stabilization system I had was a Robbe HeliCommand. Absolute rubbish. That caused more grief and wasted time than I can imagine. Although, I was terrified of tuning it and knew very little about the effects of vibrations, so maybe it was good and I didn't know it!

Either way, APM2 + TRex is awesome so far.

Cheers

Hello everyone.  First - this is my first post, and this weekend (including today) marks my first flight(s)!

I'm thrilled, and having fun (mostly).  Here's my first ever flight:  (then my question)

Now, my question:

It would seem that every time the main battery gets low (I'm running two - one for AMP2 & receiver, and 4S for ESCs/motors) one of the props quits sending the copter into a death spin. I've been fortunate that only a prop & gear has busted on my two hard "landings" - but I can't believe that the proper behavior for low voltage is a death flip (one motor stopping).

So - can you help? Is there an audible alarm anyone has rigged for low voltage - i.e LAND NOW! ??

Thanks in advance for all the guidance paid forward and all to be received!

Cheers, jake in Sonoma County, CA

DIYDrones member and SUAS News author Gary Mortimer wrote an interesting article about the first flight tests of the Boeing Hydrogen-Powered Phantom Eye UAV. The story has also been syndicated at Slashdot.

The platform will no doubt generate interest outside of military applications because a hydrogen energy storage presumably offers a higher energy storage potential than current battery technologies. I look forward to learning more about why hydrogen energy storage was selected. For those of you who follow discussions about alternative sources and storage methods for transportation, Dr. Richard Muller has a number of excellent, publicly available lectures on the realities of energy density, the (simplified) numbers behind gas, cookie powered propulsion, battery energy density and losses, and why hydrogen isn't necessarily an environmentally friendly alternative to gasoline in his outstanding Physics for Future Presidents lectures. 

While Boeing is principally targeting military applications for this platform, NASA, NOAA, and dozens of other scientific teams will no doubt have similar application requirements. If this makes sense for Boeing's perceived military applications (and I'd personally like to learn more about what design targets were met with this alternative approach) it almost certainly makes sense for atmospheric, weather, disaster assistance, search and rescue, and similar applications. 

Ben Coxworth over at GIZMAG has an article up about the new GoPro "BacPac" that attaches to a GoPro HERO to give it Wifi capabilities and the Remote that can control up to 50 GoPro cameras.

For the launch, GoPro created this video:

GoPro: New York City... A Day in the Life - Starring Skate Legend Ryan Sheckler

Read the GIZMAG: GoPro releases Wi-Fi BacPac and Remote for HERO actioncams

or the GoPro announcement

[EDITOR'S NOTE:  This topic has been posted in a previous blog.  Here's the link http://diydrones.com/profiles/blogs/walking-quadrotor-aerial-vehicle]

Hi everybody,

This is one of the toys I have designed lately as a part of my graduate project.

I have submitted it to Boca Bearing innovation contest, if you liked it, please vote for it here:

http://www.bocabearings.com/innovation-contest/ContestantDetails.aspx?ProjectID=45

This is a hybrid robot capable of both aerial and terrestrial locomotion. A unique complimentary mechanical design makes it possible to use a single actuator set for both walking and flying. This is advantageous because it reduces both the total weight of the system and the control system complexity. The basic structure is similar to a quadrotor aerial vehicle, i.e. four brushless DC motors provide the required thrust for flying. The desired leg motion is derived from two separate linear movements. Horizontal motion of the leg is achieved by driving the main actuators in reverse. A second linear actuation unit, which is set into motion by shape memory alloy (SMA) wires, enables vertical movement of the leg during terrestrial locomotion.

http://youtu.be/CHxeWsvZahY