I’m pleased to release a new publication in the Twenty-Second International Conference on Composite Materials (ICCM22) entitled “Enabling Biomimetic Morphing UAVs” with colleagues at SRI, the University of Southern California, and NextGen Aeronautics.
This publication details one application of a technology I have been helping develop with Roy Kornbluh at SRI: ultra-lightweight, ultra-low power, electrolaminate clutches for reconfigurable systems in aerospace, astronautical, and robotic applications.
Abstract: This paper reports on the design and testing of a practical, morphing wing aircraft. We intentionally mix and match elements of avian inspired design with novel technologies and proven mechanical components to provide a demonstrator aircraft that shows, in the simplest way, what benefits accrue from basic morphing changes. The simplest and most beneficial morphing concept is to change the wing area and aspect ratio, and it is easy to show that, for an otherwise fixed example configuration, a factor of three decrease in wing planform area can sustain a predicted lift:drag ratio, L/D = 9, when the vehicle flight speed U doubles from 12 to 24 m/s. Without morphing, L/D would be 6.5. Such a large area change can be achieved with a telescoping wing, which is not biomimetic, but is practicable and achievable using standard and custom 3D printed components. We combine this variation with a tail-body configuration that is bio-inspired, and suggested by previous and continuing work on the vehicle-level flight efficiency of tailless aircraft, where a standard tail geometry is replaced by a trailing edge flap that converts the cargo-carrying body into a lifting body. The practical shape-changing is enabled by the use of novel electrolaminate materials that can quickly change stiffness at varying positions/postures.
Construction of practice parts for the kinetic sculpture race begins! As practice I am beginning with the sandwheels, which are 8″ wide, 36″ diameter, truck inner tubes held in foam/glass sandwich wheels. I’ve opted to treat the wheels as practice also for the foam fiberglass sandwich construction which I now think will comprise the hull / vehicle frame. The wheels should at least be plausible for both the kinetic sculpture race and race to alaska (even if in the end I decide not to burden the longer race with any excess landing gear.)
The hubs are an interesting design opportunity to experiment also with casting fiberglass. I think I can make the hubs, with a nice conforming keyway spline in the 1″ bore, by laser cutting a simple acrylic mold around the actual shaft and spline to be used, which would be extremely well waxed with mold-release. Being a 1″ shaft, I can also thread the end of it and make a nut capable of producing a thousand or two pounds of axial force to drive the hub off the shaft, flexing the glass, if needed – it should have some elasticity.
It was an honor to be invited to present my work to the distinguished audience of DorkBot SF, held at Noisebridge, a storied and significant Hacker space in San Fransico.
DorkBot is an international speaker series whose self-summary is “People doing strange things with electricity“. In this context I presented some of the more interesting robotic, high voltage photography, and other technical art projects I’ve worked on, especially the recently completed CNC bubble iris.
Fellow presenters included the international director of the Electronic Freedom Foundation, Danny O’Brien, and Jesse Silver, the creator of BlumenLumen, a kinetic origami sculpture featured at Burning Man.
Today I got the cables laced with a new, more robust-seeming cable than the cotton yarn I’d been using. I also plumbed up the fluid delivery needle valve and solenoid, so it’s ready to go.
I let the system cycle open and closed a few thousand times while I worked, once every second or two.
A hiccup occurred when the stepper motor was accidentally overdriven due to a mis-setting of the “run current” on the Vexta stepper driver. This overheated the motor and caused a motor fault, most likely a shorted coil. Thankfully I’ve got a bin of stepper motors from various past projects and all that’s required to fix it is to 3D print a new adapter cog, which links the new motors 0.233″ diameter shaft, to the existing bicycle sprocket gear. The old adapter was a 0.25″ diameter shaft. Thankfully, modifying the CAD file, exporting a new STL model, and 3-D printing a new pulley adapter requires only about 15 minutes of my time (with the print then occurring in the background for maybe 30 minutes). Wiring in the new motor (identifying the color code of the stepper’s wires and soldering it to the cable connector) will take perhaps 45 minutes.
The Human Scale is a gorgeous film about the ways in which the organization of our infrastructure shapes our lives. Much of the last 50 years has seen cities organized around cars, with tragic consequences for common spaces and face-to-face human interaction. The human scale documents some of the best efforts at bringing cities back to life as places for human, not automotive, interaction.
I am honored to get to introduce the film and, following the showing, moderate a panel discussion with notable figures from the mayor’s office of community development, the mayor’s office Bicycle/Pedestrian Coordinator, and Bike Pittsburgh.
The Human Scale shows at the Harris Theater downtown, 809 Liberty Avenue, on Thursday November 13th at 7:00 pm. Panel Discussion to follow. Tickets are $9, and can be bought online or in person.
Can you fathom what it must feel like to be one of the astronomers who, 45 years ago, discovered a comet, and is here today watching as we as a species are rendezvousing with that comet, gently landing a 200 pound Philae probe onto the surface, while we watch from the orbiting Rosetta spacecraft 19 miles above?
This is so humbling and inspiring to witness. Congratulations to everyone involved, especially the engineers which, by the various slingshot maneuvers, accelerated this spacecraft so deep into space on such a perfectly accurate trajectory to hit a bullseye hundreds of millions of miles away!!
Watch this amazing animation of the incredible 12 year long, half-a-billion-mile, bullseye we will see stick it’s landing here in less than one hour!!