Just released in Europe and coming shortly to the United States, Parrot’s AR.Drone ($300) is billed as a “Wi-Fi Quadricopter” and “the Flying Video Game” — two pitches that don’t do justice to what Parrot has accomplished in this first-generation product. Debuted at CES earlier this year, AR.Drone is a hovercraft-like flying device that you control using an iPhone, iPod touch, or iPad using a free application called Free Flight over Wi-Fi, enabling you to look through the battery-powered copter’s two on-board cameras as it flies, with additional game apps expanding the truly novel entertainment experience. Though AR.Drone has a couple of major weak spots, particularly in the battery department, it’s impressive enough that gadget fans and early adopter types may want to take it for a spin anyway.
The AR.Drone Hardware
Parrot’s box contains the preassembled AR.Drone unit, including an “indoor” removable hull with apertures, a replacement “outdoor” red and blue hull, one Lithium-Polymer battery pack, a battery charger, AC adapter, colored stickers, a cardboard tag for gaming, and two instructional guides. Users are warned conspicuously that the packaging and the stickers are used for games, and cautioned not to throw them out.
Both the indoor and outdoor hulls are constructed mostly from styrofoam to minimize the weight of the copter, attached magnetically by placing one at a time on top of the copter. The indoor hull provides apertures to protect the rotor blades, but they’re made from styrofoam and thus somewhat fragile; normal bumps into walls and furniture are survivable, but a few crash landings will be another matter. Parrot will sell additional outdoor hulls in different colors for $20 and indoor hulls for $30, so users hoping for indoor flying in smaller spaces will want or need to budget for an extra indoor hull. That said, smaller repairs to the indoor hull can also be done with little more than some tape and/or styrofoam glue and shouldn’t affect the aerodynamics of the copter.
Why bother with different colored outdoor hulls? Parrot will offer multiplayer app games that will let AR.Drones recognize each other by color using their on-board cameras. For indoor games, the aforementioned colored stickers can be attached to the outer edges of the indoor hull.
AR.Drone’s Lithium-Polymer 11.1V 1000mAh battery is like ones included with other radio-controlled (RC) aircraft. A run time of 15 minutes is promised on a full charge, which may be startlingly low for users new to devices of this sort, but it needs to be said that RC helicopters commonly see run times of around five minutes on a single battery with the same capacity.
With such meager expectations, we were pleasantly surprised to find the AR.Drone’s actual battery life to be slightly better than Parrot’s claims. Expect considerable variations in run time depending on conditions such as wind, range, and how aggressively the AR.Drone is being flown, but for typical outdoor use you can safely expect between 20-30 minutes of continuous flying time. By comparison, hovering on autopilot indoors yielded around 45 minutes on a single charge, and multiple short flights seemed to provide up to about 60 minutes of actual in-air flying time. As with the hulls, Parrot will be selling additional battery packs for $30, and serious users will feel compelled to buy an additional battery pack or two, particularly since a full recharge takes approximately 90 minutes.
Free Flight + Real-World Testing
Parrot has released only a single iOS application for AR.Drone as of this point, the aforementioned Free Flight, although it has announced plans to release additional apps later this year including Flying Ace, an application that will allow multiple AR.Drone users to conduct augmented-reality dogfights against each other. An open SDK is also available to allow third-party developers to write their own iOS apps to make use of the AR.Drone hardware, but it’s unclear whether we’ll see much investment in such applications until lots of AR.Drones are actually in use.
Free Flight’s a good start, though. It gives you realtime access to the AR.Drone’s onboard video cameras, which let you see in front of or below the copter’s current location, plus controls: what looks like a left joystick is actually a button that takes the drone out of “hover” mode and into accelerometer control mode, while the right icon is a joystick that controls altitude (up/down) and rotation (left/right).
At bottom center is a button that makes the drone land and take off. An Emergency button at the top is used to immediately cut off all power to the rotors, which will cause the copter to drop like a rock if it’s in flight; the landing button provides a more controlled descent. The battery level for the AR.Drone is also shown in the top-right corner as both an icon and a percentage, although the percentage can sometimes be hard to read while in-flight depending on what is being displayed by the on-board camera; a different font or black background would have been helpful here.
The user can toggle through four on-board camera options by tapping a button on the left side of the screen. Two standard front camera and bottom camera views are accompanied by two additional picture-in-picture views that allow you to see both cameras at once.
The front camera provides an extremely wide 93-degree view, so you’ll need to hover very close to objects to see any kind of detail—no zoom or magnification capabilities are currently provided by either the AR.Drone or the Free Flight app. The front camera runs at 640 x 480 at 15fps while the bottom camera drops the resolution down to 176 x 144, but provides a more impressive 60 fps frame-rate. Consequently, the front camera appears to be designed primarily for navigation while the bottom camera is more suited to searching the ground below the copter or lining up for a landing. Camera performance is more than adequate for using the device, but definitely not intended to be used to capture images or video, which isn’t an option unless you use the iOS’s built-in screenshot feature. Future software from Parrot or third-party developers may be able to offer recording or photo capabilities, however the concept of a flying, mobile camera may rattle some people—probably not customers.
Settings screens allow you to adjust vehicle performance for indoor and outdoor flights and which hull is being used, allowing users to adjust the normal level trim for hovering, and select how aggressively the device responds to control movements for rotation, altitude and accelerometer controls. A “Flat Trim” button allows the user to set the copter’s normal orientation prior to takeoff which allows it to hover in a stable position on autopilot when not being actively flown.
The settings screen also provides information on the firmware versions installed on the AR.Drone; firmware updates can be applied directly through the latest version of the app.
To use the AR.Drone, you connect your iOS device via the copter’s own private Wi-Fi network, and must do this manually in the Settings app before opening the Free Flight app, an extra step that’s made a little uncomfortable by Apple’s denial of third-party access to the iOS Wi-Fi settings. The AR.Drone “pairs” with the first iOS device that connects to it and will subsequently only connect to that device. The pairing can be reset via a button on the bottom of the copter so you can connect a different device but the AR.DRone is clearly not designed to be routinely used with more than a single iOS device.
We’ve tested the Free Flight app on a variety of iOS devices including an original iPhone, iPhone 3G, second-generation iPod touch, an iPhone 4 and an iPad. Flight performance and handling on all of the iPhone and iPod touch devices was about the same and the app works well on older devices, even under iOS 4. Using the iPad was a bit different since the accelerometer controls don’t feel as natural due to the larger size; the Free Flight app is not actually a universal app, and therefore runs in 2X mode. A native iPad app might help to provide a more natural flying experience.
Flying the copter is relatively intuitive once you’ve taken a few moments to familiarize yourself with the controls. Launching is accomplished simply by tapping the button in the bottom center of the screen which will start up the four rotors and lift the copter off to a height of about three feet.
The right joystick’s altitude makes 10cm increment adjustments by tapping, or smoother climbs and descents by holding your finger on the up or down position. Free Flight’s left button acts as a press-and-hold to enable accelerometer flight, and you can simply let go of the button if you find yourself losing control of the copter, which leaves it hovering in the sky at that point. Both the left button and right joystick can actually be activated by touching anywhere on their respective sides of the screen, allowing the user to fly the copter more easily without having to continually look at the iPhone.
In calm conditions, using AR.Drone’s hovering mode for autopilot-style control of altitude is great; it knows how close it is to the ground and does an impressive job of maintaining altitude and position, even effectively climbing small hills automatically by maintaining a consistent altitude over the terrain as it goes. This is also an important consideration for indoor flight—flying over a table will cause the copter to increase its height to maintain a constant altitude over the table, possibly causing a collision with the ceiling if you’re not careful.
The ultrasound sensor on the bottom of the AR.Drone is capable of detecting height up to a range of 18 feet/6 meters. While the AR.Drone can hover higher than this, you will lose the ability to make the minute 10cm adjustments when flying at higher altitudes and the copter may not be able to adjust its height when flying over hills and other objects. An Altitude Limiter switch in the Free Flight app can be used to prevent the AR.Drone from climbing above the 18-foot range.
While becoming accustomed to the device’s controls, we kept all of the performance settings at their lowest levels which gave us a good chance to get a feel for the copter using small and basic movements. During outdoor flight, however, even in a gentle breeze it will be necessary to use slightly more aggressive performance settings simply to overcome wind resistance. The copter is quite light and easily buffeted around in stronger winds. Parrot recommends against flying the AR.Drone at all when wind speeds are greater than 7 MPH, but for your first flights outdoors you’ll want to pick as calm of a day as possible. It’s also worth noting that while the indoor hull can be used during outdoor flight, it’s not recommended as the wind will have a greater effect on the AR.Drone, making it harder to control.
For indoor flying, Parrot recommends a minimum clear area of 12 feet by 12 feet (or 4 by 4 meters). In our own experience this is clearly important as the AR.Drone generates quite a bit of downdraft in order to stay aloft. Smaller confined spaces result in air turbulence that will make it very difficult for the copter to maintain a stable hovering position, so it will flail about wildly, and usually crash into a wall. The bottom line here is that this is not something you should expect to be flying through hallways in your house, at least not without a great deal of experience in controlling the copter in more open areas.
Another interesting challenge in flying the AR.Drone is that the accelerometer controls are based on which way the copter is actually facing, so when the unit is pointing toward the user the controls are effectively reversed.