The Drone That Flies In Any Orientation

April 14, 2020 by Danie Conradie 8 Comments

Modern radio-controlled multi-rotor drone can be incredibly agile, but can only make orientation changes around the yaw axis while remaining in approximately the same position. Researchers at ETH Zurich have again built and tested multirotor with controllable motion six degrees of freedom, this time dramatically improving efficiency.

We covered a similar design from ETH Zurich previously which was hexacopter with arms with limited rotation. This new design is also a hexacopter, but with 2 coaxial motors on each rotating arm. Each arm has an increased range of rotation over the previous design, beyond 360 degrees. With the range of rotation and the very complex control system, the drone can efficiently fly in any orientation, while still being able to apply effective torque or linear force in any direction. This opens up a lot of possibilities for tasks that drones can perform, like close-up industrial inspection, using tools or pulling cables while keeping the rotors clear.

The arms do have a limited amount of rotation before winding the motor cable tight, but the control system keeps track of this and can unwind during or after movement. See the video after the break to see it in action. The complete scientific paper is not light reading, but definitely interesting. We’re looking forward to seeing if and when these type designs get used in real-world applications.

There are without a doubt a lot of drones in our future, and probably the most successful project to date is the Zipline fixed-wing drones in Rwanda and Ghana, which have made over 35000 deliveries of emergency medical supplies since 2016.

Thanks [Qes] for the tip!

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Tilt-Rotor Plane Needs Flight Controller Hack To Get Airborne

November 6, 2018 by Dan Maloney 6 Comments

Part of the charm of quadcopters is the challenge that building and flying them presents. In need of complex sensors and computational power to just get off the ground and under tremendous stresses thanks to their massively powerful motors, they often seem only barely controlled in flight. Despite these challenges, quadcopter flight has been reduced to practice in many ways, leaving hobbyists in search of another challenge.

[Tom Stanton] is scratching his creative itch with this radio-controlled tilt-rotor airplane that presents some unique problems and opportunities. Tilt-rotor planes are, as the name implies, able to swivel their propellors and transition them from providing forward thrust to providing verticle lift. With the rotors providing lift, the aircraft is able to hover and perform vertical take-off and landing (VTOL); switched to thrust mode, wings provide the lift for horizontal flight.

[Tom]’s realization of this design seems simple – a spar running through the wing holding BLDC motors and props is swiveled through 90° by a servo to transition the aircraft. Standard control surfaces on the wings and tail take care of horizontal flight. Actually getting an off-the-shelf flight controller to deal with the transitions was tricky. [Tom] ended up adding an Arduino to intercept the PWM signals the flight controller normally sends directly to the servos and speed controls to provide the coordination needed for a smooth transition. Full details in the video below, and some test flights which show that an RC VTOL is anything but a beginner’s plane.

[Tom] is proving himself to be quite the Renaissance man these days. Between air-powered piston engines, over-balance trebuchets, and popping the perfect wheelie, he seems to have covered all the bases and done his best to keep our tip line stocked.

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Greased Lightning Shows 360 Degrees

February 7, 2016 by Al Williams 41 Comments

A lot of people got drones for Christmas this year (and many Hackaday readers already had one, anyway). A lot of these drones have cameras on them. The expensive ones beam back live video via RF. The cheaper ones just record to an SD card that you can download later.

If you are NASA, of course, this just isn’t good enough. At the Langley Research Center in Virginia, they’ve been building the Greased Lightning (also known as the GL-10) which is a 10-engine tilt-prop unmanned aerial vehicle. The carbon fiber drone is impressive, sure, but what wows is the recent video NASA released (see below).

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Ducted Fan Drone Flies

July 4, 2015 by Anool Mahidharia 19 Comments

A while back, we wrote about the ducted fan, single rotor, VTOL drone that [Armin Strobel] was working on. It wasn’t quite finished then, and hadn’t got off the ground yet. He’s posted an update, and from the looks of it, he’s made tons of progress, including a first flight with successful take-off and landing.

The successful flight was no coincidence. Tuning any kind of ‘copter is a tricky business. Handling them manually during testing could be outright dangerous. So he built two different test-beds from pieces of wood, some 3D printed parts and bearings. One lets him mount the drone and tune its pitch (and roll), while the other lets him tune the yaw parameters. And just like they do in wind tunnel testing, he fixed short pieces of yarn at various points on the air frame to check for turbulence. Doing this also gave him some insight into how he could improve the 3D printed air-frame in the next iteration. He repeated the tests on the two test beds, going back and forth to make sure the tuning parameters were not interfering with each other. He also modified the landing gear to improve stability during take-off and landing and to prevent tipping. [Armin] is using the PixHawk PX4 for flight control and a BeagleBone Black for higher level functions and control.

Once the first flight showed that the drone could do stable flight, he attached a Go-Pro and recorded some nice video on subsequent flights. The next steps are to fine tune the flight control parameters to ensure stable hovering with position hold and way point following. He may also 3D print an improved air-frame. For details about the build, check out our earlier blog post on the Ducted Fan Drone. Check out the two videos below – one showing the first flight of the Drone, and the other one about the test beds being used for tuning.

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Ducted Fan Drone Uses 1 Rotor For VTOL

May 30, 2015 by Anool Mahidharia 22 Comments

Multi-rotor fixed-pitch aircraft – quad, hexa, octa copters – are the current flavor of the season with hobby and amateur flight enthusiasts. The serious aero-modeling folks prefer their variable-pitch, single rotor heli’s. Defense and military folks, on the other hand, opt for a fixed wing UAV design that needs a launch mechanism to get airborne. A different approach to flight is the ducted fan, vertical take-off and landing UAV. [Armin Strobel] has been working on just such a design since 2001. However, it wasn’t until recent advances in rapid-prototyping such as 3D printing and availability of small, powerful and cheap flight controllers that allowed him to make some progress. His Ducted Fan VTOL UAV uses just such recent technologies.

Ducted fan designs can use either swivelling tilt rotors that allow the craft to transition from vertical flight to horizontal, or movable control surfaces to control thrust. The advantage is that a single propeller can be used if the model is not too big. This, in turn, allows the use of internal combustion engines which cannot be used in multi-rotor craft (well, they’ve proven difficult to use thus far).

[Armin] started this project in 2001 in a configuration where the centre of gravity is located beneath trust vectoring, giving the advantage of stability. Since there were no hobby autopilots available at the time, it was only equipped with one gyroscope and a mechanical mixer to control the vehicle around the vertical axis. Unfortunately, the craft was destroyed during the first flight, after having managed a short flight, and he stopped further work on it – until now. To start with, he built his own 3D printer – a delta design with a big build volume of 400mm³. 3D printing allowed him to build a structure which already included all the necessary mount points and supports needed to fix servos and other components. The in-fill feature allowed him to make his structure stiff and lightweight too.

Intending to build his own auto-pilot, he experimented with a BeagleBone Black connected to a micro controller to interface with the sensors and actuators. But he wasn’t too happy with initial results, and instead opted to use the PixHawk PX4 auto-pilot system. The UAV is powered by one 3-cell 3500mAh LiPo. The outside diameter of the duct is 30cm (12”), the height is 55cm (22”) and the take-off weight is about 1.2kg (2.6 pound). It has not yet been flown, since he is still waiting for the electronics to arrive, but some bench tests have been conducted with satisfactory results. In the meantime, he is looking to team up with people who share similar interests, so do get in touch with him if this is something up your alley.

If you want to look at other interesting designs, check this UAV that can autonomously transition from quadcopter flight to that of a fixed-wing aircraft or this VTOL airplane / quadcopter mashup.

Acrobatic Tricopter Inspired By The Oblivion Movie Trailer

April 24, 2013 by Mike Szczys 28 Comments

tricopter

There have been a ton of commercials for the new [Tom Cruise] movie called Oblivion. One of the main points in every clip we remember seeing is the Top Gun meets Star Trek vehicle he does some tricks in. [James Cotton] loved that footage and ended up building his own RC version of the vehicle.

Three propellers give it lift, with directional control facilitated by servo motors which can pivot the motors attached to the two orange propellers. This design produces remarkably responsive controls as shown in the video after the break. That being said it’s still not immune to operator error. At the end of the clip [James] crashes it hard, stripping out the gears on the servo motors.

He has a few things in mind for the future of the device (and he’ll have plenty of time to plan while he waits for replacement servos to arrive). The aircraft should be able to carry a camera long with it. He discusses the issues involved with where the camera ends up pointing based on what the tilting motors are doing. But we figure he could always build a base that lets the camera pan and tilt separately from the chassis.

You can find a few tricopter projects around here but we’ve always like the one made of cardboard.

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