Yann's Techno Toys Blog

"Voyeur" hovering drone with counter-rotating rotors

Drone manufacturer Lite Machines has a video of their latest drone called the Voyeur.

It's a cigar-shaped drone, 686mm in length, 63.5mm in diameter, with two counter-rotating rotors, 762mm in diameter. It seems to be using bushless outrunner electric motors powered by a 3-cell LiPo battery.
The total mass is 1.4kg. The cruising speed is 30 knots and the autonomy 30 minutes.

There is a cool video on YouTube

Verti4: VTOL electric airplane

The Rencontres Electriques de Crespiere, an annual electric flight meeting took place near Paris last week-end. A particularly interesting design was shown this year: the Verti4. It is the simplest and most successful electric VTOL design I have ever seen. It looks like a fairly conventional trainer-style airplane with four motors on each side of the wing (two in front of the wing, two aft of the wing). The motors can pivot 90 degrees (all together) from facing up to facing forward (V22 Osprey-style), allowing a transition from hovering to translational flight. Is with other quad-rotor contraptions, two rotors turn clockwise, and two counter-clockwise on a diagonal. From what I gather from Jean-Claude and Bertrand (my dad and brother) who attended Crespiere, the stabilization and control is not done with some sort of custom electronics, but with a combination of conventional gyros, and channel mixing.

There are a few videos on YouTube:
video 1,
video 2.
video 3

Others have built quad-rotor or quad-ducted fan electric VTOL planes before (like this F35 or this strange-looking quad-EDF contraption), but not with this simple way of transitioning to translational flight.

20 gram Piper Cherokee RTF R/C Plane

Kyosho has a series of ready-to-fly R/C airplanes called the Minium that come with a complete 2.4GHz radio set.

Until recently, the only Minium plane was a small Cessna (38cm wingspan, 18 grams). The plane has been available (and very successful) in Japan, Europe and Australia under the Kyosho/Minium name. In the US, a very similar plane (if not exactly identical) has been distributed by Horizon Hobby under the ParkZone brand. It sells for $120

Now Kyosho has announced a new Minium: the Piper Cherokee. The main difference is that the Cherokee has ailerons. The plane is advertised for pre-orders for $180 on Kyosho's US e-commerce web site, but the availability date is unspecified.

What's strange is that the same web site does not have the Cessna (probably because of some exclusive contract with Horizon Hobby).
Even stranger, Kyosho's Japanese website used to have a page on the Cherokee, but it has been taken down....

DARPA-funded Nano Ornithopter Project

Aerovironment has apparently received 0.5e6 US$ to develop a nano-UAV that flaps it wings. I'm guessing Aerovironment's Matt Keenon (an micro R/C enthusiast and pioneer) must be involved in this project.

It looks like the plane could be designed to take off vertically.
The advantage of flapping wings for hovering is that you don't get a reaction torque, as with a helicopter rotor. The solutions are few: contra-rotating rotors, or oscillating blades (flapping wings).

The mechanical design, the control system, and the aerodynamic efficiency will all be challenging.

Build Furniture from LEGO-like blocks

This French furniture store sells what looks like oversized LEGO blocks called LunaBlocks, with which one can build furniture. Cool concept.

EagleTree's Altitude and Airspeed Sensors

EagleTree Systems have introduced two new sensors to their telemetry and flight recording product line: an altimeter with 1 meter resolution, and an airspeed sensor (with Pitot tube).

They cost around $40 each, and include an 7-segment LED display.
They can run standalone and display the maximum value observed during a flight, or they can plug into one of EagleTree's flight recording systems.

Using Piezo Sensors for a Drum Pad

The Drum Master is a DIY "brain" for an electronic drum pad.
The web site has some data on how to process the output of piezo-electric sensors used in drum pads.

Maze-Solving robot uses ATmega168

The arduino.cc forum has an entry describing a nice little robot that can solve mazes written on the ground with a black marker. There is a link to a YouTube video showing the robot in action.

The author used the Arduino IDE to program the ATmega-168 used on his robot. He mentions using a Pololu 3PI robot platform. This platform is not yet available from Pololu, but apparently will be soon.

Plantraco's MicroMAV

Plantraco (also known as MicroFlight.com) sells a tiny disk-shape plane called MicroMAV that looks a lot like a smaller version of my PMAV: disk-shaped wing, rudder underneath the wing.

The MicroMAV has a 12cm wingspan (my PMAV is 32cm), and weighs a mere 4g. It was designed by Henry Pasquet and Robert Guillot. It uses a single cell 20mAh LiPo, and a magnetic actuator for the rudder (no elevator). You can have it for $90 (plane only) or packaged with a transmitter for $150.

Plasma-propelled Flying Saucer?

Science Daily has a piece on a University of Florida professor of mechanical engineering Subrata Roy, who has proposed a design for a flying-saucer-shaped UAV that would be propelled using magneto-hydrodynamics. The basic idea is pretty old: ionize the air around a plane, apply a magnetic field, and inject a current through the ionized plasma. The Lorentz forces will accelerate the plasma. The principle works fine to propel model boats in salt water, but it's horribly inefficient because, although salt water conducts electricity, it has a high resistance. Much of the energy is wasted in the water. In air, the situation is worse.

The article in Science Daily merely mentions a patent, not an actual prototype. Don't hold your breath for a practical prototype...

Wireless ARMmite

at $40, the Wireless ARMmite micro-controller board from Coridium has a pretty high coolness/price ratio: a 60MHz ARM7 (LPC-2103), and a space for optional ZigBee (XBee), USB, or Bluetooth serial modules.

Korg USB mini music controllers

Korg-Japan has come up with three new USB music controllers that are the same width as a typical laptop: nanoKey (keyboard), nanoPad (drum pads), and nanoKontrol (control knobs).

Off-Road Robot Video

Okay, I'm about to switch into total bragging mode here.

This is an uber-cool video of an autonomous mobile robot that can drive itself in outdoors environments (parks, fields, forests) solely from vision. The sensors are plain cameras (well, stereo cameras). There is no laser range finders, radars, or ultrasounds of any kind. Just cameras.

Best of all, this little guy actually learns to recognize obstacles and traversable areas by driving itself around. It also learns it own dynamics.

Why the statement about bragging mode, you may ask?

Well, this is my project: I lead the team that built the software for that robot. This is one of the things I do for a living (when I'm not TechnoToying).

For more details, videos, technical papers and the like about this project follow this link to my labs web site at NYU.

By the way, this video was put together by Pierre Sermanet using Blender on Linux.

In-flight First Person Video Equipment

The latest trend in R/C flying is First Person Video. This consists in mounting a wireless camera in an R/C airplane, and flying the plane by looking at the video from the camera (generally using goggles).

The ultimate refinement is to mount a head tracking device on the goggles so as to control the pan and tilt of the camera.

A few on-line shops and web sites have popped up to cater to the new population of FPV pilots. One of these web sites is FPV Video.

Shops for FPV equipment include Hobby Wireless, and New Generation Hobbies.

Indoor 3D plane: flown automatically

For quite some time, a few of us have been toying with the idea of building an autonomous 3D aerobatic plane.

A [video] by Jonathan How and his students at MIT demonstrates an indoor 3D plane flown automatically. Technically, it is not autonomous because the plane is controlled remotely (automatically) from a ground-based computer.

The plane has no on-board intelligence: it is remotely controlled, and its position is accurately measured by a Vicon motion capture system. This eliminates the need, not only for on-bord intelligence, but also for any on-board sensors and telemetry.

The use of a mocap system is a bit of a cheat because it basically eliminates the problem of estimating the position and attitude of the plane (the Vicon Mocap system has mm accuracy at over 60 frames per second).

Still, the control is quite impressive.

A longer video showing Jonathan How research on swarm UAV (using quad-rotor DraganFlyers) is available on this page. The video was shown at the last ICRA.

Toki's SmartServo RC-1 uses Shape Memory Alloy (no motor)

The Toki Corporation in Japan has a new type of micro servo for micro R/C flying contraption. The new servo doesn't use a motor or regular actuator (electromagnetic or piezo), it uses shape memory alloy wires that the company calls "biometal".

The SmartServo RC-1 has the following specs: dimensions: 38x9x3mm, weights (with wires): 1.03g, torque: 15 g.cm, consumption: 10 mA, 0.15 W, deviation angle +- 30 degrees, operating voltage: 3 to 5 V.

The good news is that the servo is available for sale at Air Midi Micros for $32. The AMM web site has a video showing the servo in action. The technical documentation for the servo is available from Aair Midi Micros and from Toki.

Technical data about the material is available in this PDF document.

The servo apparently measures the resistance of the wire to estimate the position of the horn. Hence, the wire serves not only as an actuator, but also as a sensor (the control circuit is shown here).

Many moons ago (circa 1994), I built a micro R/C airplane with Nitinol wires from RobotStore to control the rudder. It wasn't a success, because the Nitinol wires took way too long to cool down after "contracting". The cooling time was roughly 1/2 second. Toki seems to have solved the problem, though their documentation says that the servo slows down (and the max deflection angle is reduced) after a period of continuous use.

RobotStore sells Toki's helical BioMetal wires.

16g Ornithopter from Tech. U. of Delft

The DelFly II is a radio-controled ornithopter with an on-board camera built by the University of Delft.

The specifications are quite impressive: 16 grams, 1.6g outrunner brushless motor, 130mAh single-cell LiPo battery, autonomy: 8 minute of hovering, or 15 minutes of horizontal flight, 15 m/s max speed, -0.5 m/s min speed,
30cm maximum dimension, electromagnetic actuators for elevator and rudder control. They also claim video-based trajectory stabilisation, target recognition, and such (see the second video).

There are photos, and movies
here, and here.

Boarduino: breadboard-compatible mini Arduino

Over the last few months, I have become rather fond of the Arduino microcontroller board concept. I like its simplicity, its open design, and (last but not least), the fact that the development environment runs seamlessly on Linux.

One shortcoming of most Arduino boards is that they are rather bulky (not good for putting them onbard a small airplane). While the Arduino Mini has been available for a while, it is not as convenient as the new $17.50 Boarduino kit from Ada Fruit.

The Boarduino has everything a regular Arduino has, but it is much smaller and can plug into a breadboard.

Single-chip 6 DoF IMU from Analog Devices

Speaking of Jeff Han: Jeff pointed me to this new device, recently announced by Analog Device. Many people were anxiously waiting for something like this to appear: single chip that contains 3 accelerometers and 3 gyroscopes that can be used to build a full, 6 degree of freedom inertial measerument unit (IMU).

The part is called the ADIS16355.
It uses an SPI interface, and even includes an auxillary 10-bit A/D converter, an auxillary D/A converter, and two digitial I/O
(see data sheet).

Now for the bad news: the price is $360 in 1000 quantity (ouch!).

It's still a lot cheaper to buy a 5 DoF break-out board for $110 from sparkfun (3 accelerometers, 2 gyros), plus another gyro, and a cheap micro-controller.

Jeff Han's Multi-touch panel at Neiman-Marcus?

My friend and colleague Jeff Han has been getting a lot of attention in the last year or two with his amazing multi-touch display panel (see various videos here and here, and
his August 2006 TED talks)

Jeff has started a company in New York City called Perceptive Pixel.

The funny thing is that the upscale department store Neiman Marcus is offering Jeff's "online media wall" in the "fantasy" part of its Christmas catalog. The price is "starting at 100,000". If you have to ask.....

There is a nice video on the Neiman Marcus site too.

New Li-Ion Batteries from A123 charge in 15 minutes

Battery manufacturer A123 Racing is offering a new type of Lithium-Ion batteries for model cars and airplanes that can not only put out enormous amounts of current, but can also be charged in 15 minutes.

A123 Racing is a sub-brand of manufacturer A123 Systems, who has been producing the new type of battery for a while. They were so far mainly used in rechargeable cordless drills.

The so-called Hypersonic cell has the following characteristics: capacity: 2300 mAh; nominal voltage: 3.3V; internal impedance: 10 milliohms; max continuous discharge: 70A (30C); burst discharge (10 seconds): 120A (60C); fast charge current: 10A (4C), which translates into a charging time of 15 minutes; mass: 70 grams; price: $20.

A 3S1P pack costs $90, and the special charger is roughly $100.

The energy per gram is not as good as a LiPo, but you can't beat the charging time....

EEstor super-duper-ultracapacitor

Startup company EEstor claims to have produced ultra-capacitors with en energy density of 280 Watt-hour per Kilo. When you realize that your typical LiPo battery is around 140 Wh/kg your interest level goes up a notch. Given that ultra-capacitors can be charged extremely quickly (in seconds), and have a huuuuge maximum current, this might just be the miracle power source, not just for model ariplanes, but also for (full-scale) cars, which is EEstor's main target.

The main limitation of garden-variety ultra-capacitors (the ones you can get from DigiKey) is that they have a very low breakdown voltage (like 3V). The energy per unit mass sucks. It's enough for those e-charger toy airplanes from AirHog with a 10 second running time, but not for R/C planes. Since the energy stored in a capacitor is quadratic with the voltage (1/2.C.V^2) increasing the breakdown voltage can make a big difference. That's apparently what EEstor has done: they were able to raise the breakdown voltage to 1500V....

EEstor doesn't really have a web site, but there was a nice article on them at Technology Review back in January.

Hi Again

After a long hiatus, Yann's Techno Toys is back in business.
A large backlog of Techno Toys awaits us.

Paparazzi: Free / Open Source Autopilot Project

Paparazzi is an open source hardware/software project whose goal is to provide a complete autopilot system for UAVs.

The Paparazzi project is hosted at the "Ecole Nationale de l'Aviation Civile" (ENAC) in France, and is the basis of ENAC's autonomous UAV project.

The hardware is built around a Philips LPC2148 ARM-7 chip. It includes a GPS and Pyro-electric infrared sensors for pitch and roll angle detection (no gyros).

Crespiere 2007

Crespiere 2007, an annual get-together of electric R/C airplanes in France, took place last week. I'm told the weather was sub-optimal (very high winds), and the turn out less than usual (because of the weather). Web magazine RC Pilot Online has a picture gallery of the event.

I was intrigued by this weird-looking plane that looks like a Calder scultpure.

There is also a picture of my dad's new CAP-10 . Unfortunately, bad weather prevented test flights before Crespiere, hence it didn't fly during the event.

Nice Electric UAV video from Trek Aerospace

Trek Aerospace has demonstrated a small, electric powered UAV called the OVIWUN. It has two contra-rotating ducted fans on each side of a "fuselage". The ducted fans can be independently tilted forward or backward to control yaw and pitch (as well as forward/backward translation). Roll is apparently controlled by changing the relative speed of the rotors. Each rotor is powered by a 450 Watt electric motor. The UAV is 36cm tall, 65cm wide, 41cm long, and weighs 2520 grams (with batteries). They claim an endurance of 20 minutes, and maximum speed of 75km/h (which I find very hard to believe).

The $15,000 price is a bit steep for something many of us could probably build in our shop. However, the good news is that UAV is controlled by an Xscale-based single-board computer running Debian Linux, and comes with open source flight control software.

There is a nice video of the OVIWUN's indoors test flights

Tech reports on the 2006 UAV competition

This page has a collection of papers by the participants of the 2006 student competition of Unmanned Air Vehicles. There is quite a lot of details about the hardware used in each of the participants' planes.

Kestrel Autopilot for Micro UAVs

Procerus Technologies offer the Kestrel micro UAV auto-pilot. It weighs 16.5 grams and contains a 6 degree of freedom inertial measurement unit, a magnetometer, an absolute and differential altitude sensor, and an airspeed sensor. It's built around a Rabbit micro-controller. The only thing that's not light about it is its price: 5 kilodollars.

Wowwee's R/C Dragonfly

My friend Jeff Han recently went to the TED Conference and brought back one of Wowwee's new Flytech R/C Dragonflies. I tried it out and took a few close-up pictures.

The dragonfly flies quite nicely. Its control system is somewhat unique: it has a small propeller on the tail (spun by a pager motor) to pull the tail to the left or to the right. It has a "beginner" mode and an "expert" mode. In beginner mode, the Dragonfly turns rather sluggishly, but in expert mode, it is quite maneuverable. However, it loses a lot of altitude in tight turns, so flying in cramped spaces takes a little bit of practice.

There are 4 wings, but they actually are rigidly attached in pairs. The pairs oscillate in opposite phase as shown on this picture.

The LiPo battery is recharged in 25 minutes (probably not to full capacity) by plugging the Dragonfly into the transmitter. A magnet hods it still on the transmitter.

More pictures are available here.

The Dragonfly is available from Radio Shack for $50.00

UPDATE: Doug Setzer points us his DragonFly forum, and to this photo series that shows the innards of a dissected DragonFly.

Reflex Helicopter from SpinMaster/AirHogs

SpinMaster came out with the Reflex R/C Helicopter. Like many recent toy R/C helicopters, the reflex has two contra-rotating rotors for stability. The new twist is that it has two "thrust" motors and prop (one on each side of the body) to make it move forward, backward, and to rotate. They claim an un-precendented maneuverability, which I can believe. It has to be easier to control than the Picoo-Z and AirHogs's own Havoc.

The price is $70.

FoxBoard: tiny Linux board from Italy

ACME Systems in Italy is selling the FOX Board, a tiny 66x72mm, 37gram board built around the ETRAX 100LX CPU from AXIS Communications. The board runs Linux 2.4.x or 2.6.x.. It has USB, Ethernet, and can support webcams through the spca5xx-le driver. It sells for 130 to 150 Euros, depending on the version.

The FOX Board can accept a daughterboard called FOX VHDL which has a 250K gate Actel ProAsic3 FPGA. Hmmm....

Some people have done pretty cool things with the FOX Board, including this hexapod robot.

Qwerk: All-Inclusive ARM-based Linux robot controller

For some time now, Charmed Labs has been selling the Qwerk embedded robot controller ($350). It has a rather unique combination of features: ARM9 CPU with FPU, Linux and eCOS operating systems, a Xilinx Spartan 3E FPGA for fast custom I/O, ethernet, Wifi, USB ports with Webcam support, 4 DC motor controller (2.0 Amps), 16 servo outputs, 8 Analog inputs (12 bits), 16 digital I/O lines, quadrature encoder inputs. The software was developed at CMU. The Qwerk is the basis of CMU's Terk Telepresence Robot Kit.