Meet the Bat Bot: Aerial Robotics and Biomimetics Research Result in Caltech’s New Autonomous Drone

Look, up in the sky! It’s a bird, it’s a plane, it’s…Batman! In my humble opinion, this is how that phrase should really go; Superman has always been a little too squeaky clean for my liking. I know that Batman can really only fly when he’s in the Batcopter, but that’s part of why I like him – he’s not an actual superhero with superpowers. Granted, he’s a genius billionaire with all kinds of resources, but even so. So I guess a more accurate phrase would be, “It’s a bird, it’s a plane, it’s…a bat!” But today, I’m not talking about an ordinary bat. I’m talking about Bat Bot, the awesome result of aerial robotics research by Caltech and the University of Illinois at Urbana-Champaign (UIUC). This creation was inspired by the real flying mammal itself, and scientists hope that over time, Bat Bot can be developed for use in fields like disaster rescue and personal assistance.

Bat Bot is an autonomous drone, even though it resembles a bat. According to Caltech associate professor of aerospace and Jet Propulsion Laboratory researcher Soon-Jo Chung, “bat flight is the holy grail of aerial robotics,” because bats have what is likely the “most sophisticated powered flight mechanism among animals.” The flying motions of insects and birds are easy to recreate, but bats’ wings have a complex musculoskeletal system, with several types of joints that interlock the bones and muscles to each other, creating movement in over 40 rotational directions. In addition, each wing can move separately in an asymmetric manner, making bats extremely flexible and agile.

Chung, together with his former UIUC postdoctoral associate Alireza Ramezani and Ramezani’s co-advisor Seth Hutchinson, UIUC professor of electrical and computer engineering, just jointly published a research paper in the Science Robotics journal describing their self-contained Bat Bot, or B2 as it’s called in the paper, with soft, articulated wings. The study is titled “A Biomimetic Robotic Platform to Study Flight Specializations of Bats,” and the research was funded by the National Science Foundation’s National Robotics Initiative.

Chung said, “This robot design will help us build safer and more efficient flying robots, and also give us more insight into the way bats fly.”

The research team learned that the most important components of how bats stroke their wings are the side to side tail swish and the shoulder, elbow, and wrist bend. One of the major research challenges was to create wings that were able to change shape while flapping, mimicking a bat’s wing. Nylon and Mylar were determined not to be stretchable enough for the task, so the team developed a soft but strong, ultra-thin (only 56 microns) silicone-based membrane, which covers the nine key joints of the Bat Bot’s one-foot wingspan.

The paper abstract states, “We have successfully achieved autonomous flight of B2 using a series of virtual constraints to control the articulated, morphing wings.”

The Bat Bot only weighs 93 grams, and was built using lightweight carbon fiber bones and 3D printed socket joints. Most flying robots use spinning rotor blades, or up and down flapping motions, to lift off and propel into the air, which is fairly limiting. But the Bat Bot is able to alter its wing shape by extending, flexing, and twisting at its wrists, legs, shoulders, and elbows, and move each wing independently of the other. The flapping of the wings amplifies the motion of the robot actuators, and it also conserves the little animal-shaped drone’s battery power, both of which make the Bat Bot quieter and more efficient than quadcopters or fixed-wing drones.

Ramezani says, “Our work demonstrates 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.”

The innovative Bat Bot design could have applications in tricky environments where traditional quadrotor drones, with four spinning motors, could cause damage or injuries by colliding with objects or people. So while the Bat Bot’s current battery technology is too chunky to let it fly for a really long time, the team believes that this could be further developed, and used more effectively in urban environments.

Watch the video to learn more about how Bat Bot was created:

Discuss in the Bat Bot forum at 3DPB.com.

[Source: Caltech]