Wing-flapping micro robots, unmanned helicopters, formation flight algorithms -- there were lots of cool UAV projects at the International Conference on Intelligent Robots and Systems (IROS) last week in San Diego, Calif. Too many, in fact, to describe them all here. But Automaton correspondent Marcel Bergerman, a systems scientist at Carnegie Mellon, has the highlights:
Greetings from San Diego! I am at IROS 2007 looking at the latest developments in unmanned aerial vehicles (UAVs). IROS is a huge conference, with 132 technical sessions in 11 parallel tracks over three days, plus three plenary sessions and several workshops.
UAVs alone got four sessions, which is an indication of the importance of the field among the myriad of disciplines that comprise robotics today. The weather was great, and luckily the forest fires that abated San Diego did not interfere with the conference. More than 1,000 people registered for and attended IROS, making is one of the premier robotics conferences worldwide.
Instead of covering each UAV paper presented in a succession, which would be just plain boring, I decided to report on those works that I found interesting or novel (in no order of importance). The pictures below were taken from the conference CD-ROM; of course, these carry the IEEE copyright, but since this is an IEEE blog, I figured it would be OK to publish a picture or two (or three).
Under the category "design of micro UAVs" I enjoyed the works of Robert Wood (Harvard) and Xinyan Deng (University of Delaware). Wood is designing insect-size UAVs that actually flap their tiny little wings to generate enough lift to keep the vehicle aloft, with some lift to spare for an onboard processor and sensors.
Transmission system for one of Robert Wood's micro aerial vehicles.
He described the fabrication process for each of the components, which is rather involved. Videos shot with high-speed cameras show the wings flapping at 110 Hz very robustly. I look forward to some future conference where Wood shows these tiny UAVs flying with some degree of autonomy.
Robert Wood's 60 mg, 3 cm wingspan micro aerial vehicle.
Deng is also working on insect-like UAVs; although she showed results with "large" wings on the order of several centimeters, she mentioned that her tests are coherent with real insects in terms of Reynolds number and advance ratio (the ratio of flapping frequency to flight speed).
Xinyan Deng's prototype dragonfly robot.
Talking about bigger machines -- Our group at Carnegie Mellon (yes, I did find our work interesting) :-) presented a novel model-based cascaded controller for the Yamaha RMAX unmanned helicopter. The model is adapted from work published in 2006 by NASA's Mark Tischler in the Journal of the American Helicopter Society; I believe it will slowly replace Mettler's as the basis for small helicopter simulation and controller design models.
A quadrotor built at ETH Zurich also caught my attention, especially the video where the machine avoids people walking towards it.
ETH's quadrotor in hover.
On a higher level of abstraction I would like to mention Rachid Alami's (from the LAAS/CNRS, France) formation flight algorithm, which allows UAVs to adopt the best possible convoy formation for a given mission profile. The algorithm takes into account threats such as enemy-operated jamming radars which would disrupt communication between the UAVs and between them and a ground control station. Alami's group has started experimenting with three small fixed-wing airplanes.
Alami's formation flight algorithm applied to an 8-UAV fleet.
Overall there were 20 UAV-related papers from four continents and eight countries, including Portugal, Germany, France, Switzerland, Japan, Australia, Mexico, and Brazil. This shows how international is the UAV community!