No matter how much effort they put in, even the most progressive robotic enthusiasts on Earth struggle to recreate the elegance and beauty of nature. Most difficult of those recreations is copying the efficiency and charm with which birds fly through the air. The “PigeonBot” of Stanford researchers makes a step toward transforming that by investigating and exhibiting the uncommon qualities of feathered flight.
Seems like a ‘School project’
On a cursory level, PigeonBot seems a bit like a ‘school project’. However, a lot of brainstorming was involved behind this rather desultory-looking design. It seems like it is not very well understood, how birds fly. This is because the link between the dynamic wing shape and individual positioning of feathers is a super complex concept.
David Lentink, a professor for Mechanical engineering challenged few of his graduate students to “dissect the biomechanics of the avian wing morphing mechanism and embody these insights in a morphing biohybrid robot that features real flight feathers,” considering a common pigeon as their model, the flexibility of which Lentink praises.
As he describes in an interview with the journal Science:
“The first Ph.D.student, Amanda Stowers, analyzed the skeletal motion and determined we only needed to emulate the wrist and finger motion in our robot to actuate all 20 primary and 20 secondary flight feathers. The second student, Laura Matloff, uncovered how the feathers moved via a simple linear response to skeletal movement. The robotic insight here is that a bird wing is a gigantic underactuated system in which a bird doesn’t have to constantly actuate each feather individually. Instead, all the feathers follow wrist and finger motion automatically via the elastic ligament that connects the feathers to the skeleton. It’s an ingenious system that greatly simplifies feather position control.”
Studying the Wing Structure
The team observed that the single control of feathers is much of an automatic process than a manual one. In addition to it, the team also explored that small microstructures on the feathers create a sort of one-way Velcro-type mesh that allows them to form a continuous surface rather than a surface formed by a bunch of disconnected ones. These along with the other findings were published in Science. Whereas ‘the robot’ crafted by Eric Chang, “the third student,” is mentioned in Science Robotics.
The design was made using 40 actual feathers of pigeon along with a super-light frame. Chang and his team designed a simple flying machine that doesn’t achieve the lift using its feathers; it has a propeller on the front. However, it uses the feathers to steer and maneuver utilizing the same type of flexion and morphing as an actual bird does while gliding.
Understanding the biology of the wing, then observing the details and tuning the PigeonBot systems, the team explored that the bird (and bot) made the use of its “wrist” while the wing was partly taken back, and “fingers” when stretched, to control the flight. However, it’s performed in a highly delicate fashion that minimizes the thought and the mechanisms required.
The design can be productive for UAVs
This kind of innovation can result in improved wing design for aircraft, which right now is based on principles established more than a century ago. Of course, Passenger jets don’t need to dive or perform a belly roll on a quick command. However, UAVs and other small craft might consider the ability extremely productive.
“The underactuated morphing wing principles presented here may inspire more economical and simpler morphing wing designs for aircraft and robots with more degrees of freedom than previously considered,” write the researchers in the Science Robotics paper.
The next process for the team might be observing different species of birds. Lentink has been working on a tail design to synchronize with the wings, and separately on a new bio-inspired robot idealized by falcons, which could incorporate legs and claws as well. “I have many ideas,” he accepted.
Hello, I’m Anna Yeo. If you like my news coverage, please drop a good word in my inbox. I’m journalist by profession and have been part of many major reporting across the globe. I like to write crisp and factual news. I have completed my masters degree in journalism. Feel free to contact me at [email protected]