Posted by Joe Renteria on February 21, 2017 at 9:46am
Separate lift/thrust systems are growing fast in popularity, to the point that there are already a variety of commercially available systems. They seem to be the future and continually get better. Thanks to our developers, Ardupilot has some great features like holding position with forward thrust and is becoming very good at leveraging the benefits of an SLT system. These systems have the potential to perform very well in windy conditions, since airplanes rely on wind to fly. It is only a matter of time before the developers have it perfected. The main argument against SLT systems, is the dead weight they carry around. The large majority of propulsion weight, is dead weight 95% of the time.
This concept, the tilt rotor/SLT hybrid is an attempt to reduce this dead weight by using horizontal propulsion during both VTOL and cruise. Compared to typical SLT systems, this would allow lift motor weight to be much lighter. Unlike typical tilt rotors, nacelle propulsion could be highly optimized for forward flight while the usual structural requirements on the wing would be reduced with the wing being supported at multiple points along the span.
Nacelles could be controlled by differential thrust, containing an IMU and stabilized independently from the main body, eliminating the need for actuators or mechanics of any kind. The nacelles would be able to tilt forward during VTOL to help with position holding as well as provide very powerful yaw control which is typically a problem for SLT systems.
Feel free to comment. I would love to get some feedback, good or bad.
I have more info, images and videos about this concept here:
Posted by Joe Renteria on December 15, 2016 at 11:17am
UAS Vision published an article on these EDFs optimized for static thrust. Something I am constanly googling around for but never seem to find...
"The pan-European Neva Aerospace consortium, which is developing heavy-duty drones, industrial and commercial unmanned aerial systems (UAS) and vehicles (UAV) based on its patented distributed thrust concept, has released the first OEM electric turbofan (ETF) to the aerospace market. These ETFs are claimed to be between two and four times as efficient as existing, standard electric ducted fans (EDFs).
The Neva Athena ETFs are a world first and are the only ducted fans optimised for static thrust and VTOL/STOL. A unique turbofan housing design further boosts the thrust without any compromise on weight saving.
The breakthrough technology of the Athena Series turbines will displace uncaged rotor blades in current commercial drone applications and will create exciting new possibilities for the development of the next generation of unmanned aerial systems.
Athena ETFs will be able to lift drones of more than 25kg with 10 turbofans across a surface of less than 1.5m diameter, according to Neva engineers.
The Neva technology is scalable nearly infinitely and limited only by the energy density of batteries, the capabilities of controllers and, as these technologies advance, the imagination and audacity of drone designers. Other models in the Athena Series are under final development and testing."
Posted by Joe Renteria on November 22, 2016 at 2:25pm
Hello everyone, I have posted about this idea before in the form of an aircraft which could transition between vertical and horizontal flight. While I believe it is possible, especially in the form of a flying wing, the response I have received from this site as well as other sources indicates that most observers have serious doubts.
I have decided to focus on non-transitioning embodiments to eliminate that doubt for now, and hopefully get some feedback on the concept as a purely rotary wing airframe, the helicopter.
What is the point of this weird helicopter? The goal here is mechanical simplicity, turning a mechanical challenge into a software challenge. This is why multirotors are so popular. They are mechanically simple, and the rest is configured and reconfigured with code. The code can then be copied, altered, provided at little or no cost, and never wears out or needs replacing. The above concept would require eight moving parts.
This idea would require only three positioning sensors, one for the main shaft, and two for the rotors, and these can be simple rotary position sensors or IMUs which evaluate their position in relation to each other.
I would really appreciate any feedback or ideas anyone might have about this.
Posted by Joe Renteria on October 15, 2016 at 6:20pm
Hey everyone, I would love to get your opinions on this concept...
I am working on a rotary wing design, and this is a monocopter version of it. It has only two moving parts, the two propellers. The two props drive the wing around an avionics hub while also controlling the pitch of the wing throughout the cycle through differential thrust. The battery is used as a counterweight.
The symmetrical airfoil is stable, so it should not put up much of a fight as far as pitch control goes. If you are wondering about the motors ability to go through throttle changes fast enough to execute a cycle for every rotation, many monocopters already use cyclic throttle pulses to maintain control.
The advantages would be:
1. The elimination of servo cost, weight, complexity.
2. Direct, structurally efficient cyclic pitch control over a larger wing, current systems use a servo to control the pitch of a very small wing, and usually just a control surface on the wing.
Posted by Joe Renteria on October 4, 2016 at 12:35pm
Hey everyone, I think we all can agree it has been an eventful year. It has been almost a year since I posted a concept I was working on here, and some of you were kind enough to let me know what you thought. I have continued tinkering with this idea, and was hoping I could get another round of comments and criticism from anyone who has a minute to spare. If you have any insights on this I really would like to hear them, even if they are less than optimistic...
Thanks!
There is a little more info about this concept here: Pivotwing.com
What started as a 1/6th scale model and an audacious (and ultimately doomed) Kickstarter campaign less than two years ago, has progressed to something people can actually strap into and ride. Well, not just any people. For its first foray into wind tunnel testing of its full-scale WingBoard, Wyp Aviation turned to Brandon Mikesell, a wingsuit-wearing maniac who spends his days leaping off mountains and gliding through majestic valleys.
Crafting the full-scale WingBoard prototype began with blue structural foam, which was then coated with layers of fiberglass and carbon fiber, incorporating plywood ribs to help distribute the loads. The prototype is broken down into five sections and assembled by joining each together with carbon fiber tubes. Flight control is handled by commercial and RC aircraft servos, with an autopilot function used to keep the wings level.
The testing took place over two days at the Ontario Institute of Technology's ACE (Automotive Centre of Excellence) wind tunnel, where the WingBoard was subjected to flight speeds of 55 to 75 mph (88 to 120 km/h). The testing was designed so that the WingBoard would feel the same forces as it if was being towed along by an aircraft, with a Y-shaped tow line harness connected to a point around 45 ft (13 m) inside the wind tunnel contraction.
The team evaluated the board's performance over four hours of flight and found that it behaved as hoped, with takeoff speed within 5 mph (8 km/h) of predictions and the drag forces within 10 lb ((4.53 kg). Most of the testing was carried out by Mikesell, but part of the exercise was also to get an idea of how easily beginners can learn to fly the WingBoard.
To this end, a member of the team with no skydiving but a little wakeboarding experience was ushered onto the WingBoard to gauge the learning curve. With guidance from Mikesell, the novice WingBoarder learnt to fly smoothly within 15 minutes of strapping in, noting the easy transition between wakeboarding and its nascent aerial counterpart.
"This has been an unqualified success, we could not have hoped for this to go any better than it did over the last two days," says Wypyszynski. "We hit everything we ever hoped we could, it actually got to the point that after the first couple of tests we sat there and were like 'Well now what do we do, it's going so well, what else can we get out of the test today, how much more can we figure out?' and really got a lot further than we thought we would get."
From here, the team plans to move onto real world testing behind real world aircraft in the real world sky. This next stage will play out across a few phases, beginning with helicopters without tail rotors, such as the MD-500 NOTAR or K-Max. A standard tow plane, such as a Piper Pawnee, will follow, which will allow the team to test out the takeoff and landing techniques.
These bookends to the WingBoarding experience are elements that Wypyszynski has put a fair bit of thought into. He ruled out the idea of having the rider dispatched from the aircraft when it is already airborne due to stability issues. Instead, riders will take to the skies the same way as a glider, with the board towed along in a rolling takeoff. Landing can play out a couple of ways, with the rider either freeing themselves from the board and parachuting back down to Earth or through a rolling landing similar to the way they took off.
Assuming this part of the testing goes to plan, the team will move onto more aerobatic pursuits, using a suitable aircraft to engage in rolls, inverted passes and formation flying. These first flights behind aircraft are hoped to kick off later in 2016 or early 2017, before the team takes the WingBoard on tour around the airshow circuit. While the company hopes to eventually sell WingBoards to individuals, they are also looking to build facilities where daredevils can pay for a single-flight experience similar to a skydive, and apparently at not much more of a cost.
I still don't like the design but i guess I am warming up to it. I think some benefits are that distributing lift over the span of the wing helps structurally, fast moving air over the top of the wing prevents stalling during transition and increases lift during flight and the canard setup is good for cg during hover if you have your thrust mounted to your wings...
Posted by Joe Renteria on November 17, 2015 at 2:00pm
Hello all,
I am working on a VTOL concept and thought I would post it here. I hope to get as much feedback as possible from anyone who has any. The depicted airframe is the simplest embodiment that would be capable of both rotary and fixed wing flight. Alternative versions could look very much like a conventional helicopter having a stationary fuselage and a very small tail rotor or control surface. This is basically just my website copied and pasted. This is a concept only at this point, no prototype. Also, the ducted fans were just for simplicity for the animation, not necessarily for the working aircraft.
In under a year, the team of flight enthusiasts at Bay Zoltan Nonprofit Ltd., a state-owned applied research institute in Hungary, has taken the concept of a personal flight tricopter from the drawing board to its first manned flight at Miskolc Airfield in northeast Hungary on March 7.
On the manned flight, the Flike (think fly-bike) concept demonstrator had a takeoff weight of 210 kg (463 lb) and only made it off the ground for a few seconds, but took off and landed safely. In a subsequent manned test flight, the Flike fly meters off the ground, and was able to demonstrate hovering and maneuvering capabilities while compensating for wind in a controlled flight lasting one and a half minutes.
I know that gimbals are really cool and make great things possible, but I just can't wait for them to die. They are heavy, draggy and add complexity. It would be great to just record everything and then scroll to the portion on video you want to see. If you are capturing video for a production, you can fix it in post. If you are doing surveillance, you could completely stabilize your view with software. Maybe this will get us one step closer: http://bit.ly/1gV7n2c
