February 2, 2017
New bat-inspired drone is the ‘holy grail’ of flying robots
Flying robots are nothing new, but one inspired by the complex flight mechanics of the bat? That’s being hailed as “the holy grail of aerial robotics” by the biomimetric researchers who have successfully developed such a machine, according to CNET and Engadget.
While engineers have previously replicated the flight mechanics of birds and winged insects in their autonomous flying drones, bats have been a far greater challenge, as they have more than 40 joints in their wings, enabling them to fly with unrivaled agility and maneuverability.
Now, however, as researchers from the California Institute of Technology and the University of Illinois at Urbana-Champaign reported this week in Science Robotics, they “have created a fully self-contained, autonomous flying robot that weighs 93 grams, called Bat Bot (B2)” which they stated is able to “mimic” the “morphological properties” of a bat’s wing.
“Bat flight is the holy grail of aerial robotics,” study author Soon-Jo Chung, a Caltech professor as well as a researcher at the Jet Propulsion Laboratory, told reporters during a press conference. They did so, Engadget explained, by simplifying a bat’s wing structure to just nine joints.
Lightweight unit is maneuverable, but not quite ready for field work
Chung’s team covered those joints with stretchable silicone-based membranes, a design which they said “best match the morphological characteristics of bat flight.” The silicone membrane is just 56 microns thick, giving Bat Bot a wingspan of approximately one foot. Furthermore, it has a skeleton made from carbon fiber and its socket joints were made using a 3D printer.
During the development of the Bat Bot, the researchers explained that they identified dominant degrees of freedom (DOFs) in the flight mechanisms of bats, then incorporated those DOFs into the design of their robot using “a series of mechanical constraints” including “asynchronous and mediolateral movements of the armwings and dorsoventral movements of the legs.”
Co-author Alireza Ramezani called Bat Bot “one of the most advanced designs to date of a self-contained flapping-winged aerial robot with bat morphology that is able to perform autonomous flight.” Like a real bat, B2 can moving autonomously and is able to alter the shape of each wing to perform complex aerial maneuvers that would otherwise be impossible, said Engadget.
Of the nine joints they used to recreate bat flight mechanics, four are passive and five are active, CNET noted. These specific joints were chosen since they were deemed to be the most important to the creature’s wing stroke, and because copying the exact anatomy of a bat’s wing would have caused the drone to have been too heavy to fly.
The joints that were selected involve moving both the shoulder and elbow, bending the wrist and helping the tail move from side to wide, the website added. However, B2 needs a little more time and some tweaking before it is ready for field work, the researchers said: its electronics currently are too delicate to survive crashes, and improvements need to be made to its battery as well.
Image credit: Caltech