Although the act of perching appears to be quite simple when a bird lands on a limb. It actually requires a very precise balance of time, high-impact forces, speed, and precision. No flapping-wing robot Ornithopter has been able to master it. Until now because it is such a difficult maneuver.
Raphael Zufferey, a postdoctoral fellow in the Laboratory of Intelligent Systems (LIS) and Bio robotics lab in the School of Engineering, is the first author on a recent Nature Communications paper. He describes the unique landing gear that makes such perching possible. He built and tested it in collaboration with colleagues at the University of Seville, Spain. Where the 700-gram ornithopter itself was developed as part of the European project GRIFFIN.
This is the initial stage of a bigger undertaking. An ornithopter has the ability to perform specialized tasks, such as discretely collecting biological samples or measurements from a tree. After it has mastered landing autonomously on a tree branch. Eventually, it might even touch down on man-made structures, which would expand the potential applications.
Ornithopters, like many other unmanned aerial vehicles (UAVs), have limited battery life. Therefore the ability to land on a perch may offer a more effective means for them to recharge using solar energy. Perhaps making them perfect for long-distance missions.
This is a significant step toward manipulative tasks and other practical uses for flapping-wing robots. Which can currently only do free flights. It is just like a modern drone modified version having a free will.
Ornithopters, the flying wing robot
Maximizing power and accuracy while reducing weight and speed
Engineering challenges included controlling numerous parameters that nature has previously so expertly regulated in order to land an ornithopter on a perch without any external commands. As it perched, the ornithopter needed to be able to considerably slow down while keeping flying. The claw has to be powerful enough to hold the perch. And sustain the robot’s weight without being too heavy to lift. That’s one of the reasons we chose a single claw rather than two. The robot also needed to be able to understand how its surroundings and the object in front of it relate to its own position, speed, and trajectory.
The ornithopter was outfitted with a fully on-board computer and navigation system, which the researchers used in conjunction with an external motion-capture system to aid with positioning. As it attempted to focus on and hold the perch, the ornithopter’s leg-claw appendage was finely adjusted to account for the up-and-down oscillations of flight. The claw was built to support the robot’s weight and absorb the robot’s forward momentum when it hit. It was also built to close quickly and firmly. Once perched, the robot stays there without using any energy.
