RoboBat (B2): Introducing a Bat Robot Drone from the University of Illinois
What started as casual robotics conversations between engineering professors has resulted in a $1.5 million National Science Foundation (NSF) grant to build mechanical bats for construction sites.
CSL Professor Seth Hutchinson has teamed with CSL and Aerospace Engineering Assistant Professor Soon-Jo Chung, CSL and Aerospace Associate Professor Timothy Bretl, and Civil and Environmental Engineering Assistant Professor Mani Golparvar-Fard to develop this project with the goal of building a robot with the characteristics of a bat that would be able to supervise construction sites.
“Building construction projects are complicated, and rarely do they happen the way they are intended to happen,” Hutchinson said. “Keeping track of whether the building is being put together the right way at the right time is not trivial. So the bats would fly around, pay attention, and compare the building information model to the actual building that’s being constructed.”
Hutchinson will focus on the higher-level aspects of the robot planning and control algorithms, such as planning flight trajectories that take into account the constraints imposed by operating in a human environment. Chung has been working on the flight control and dynamics of bat-like aerial robots as well as on synchronization and PDE control of flexible articulated wings, and will be the key researcher in the design and control of the robot bats. Bretl will contribute work on the motion planning of the robot, while Golparvar-Fard is researching the various applications this robot can have on a building construction site.
The team of Illinois engineering professors is also collaborating with Brown University professors Kenneth Breuer and Sharon Swartz. The two groups worked jointly on the proposal that was sent to the NSF National Robotics Initiative (NRI). The Brown University researchers were awarded $700,000 for their portion of the research in addition to the $1.5 million grant given to Illinois team. The money for the project arrived this past August, and Hutchinson expects a prototype to be ready by the end of this summer.
Both Breuer and Swartz are world-renowned experts in the field of bat flight, and their research will provide insights into biological flapping flight. The Illinois engineers then plan to take that information and apply it to the robot bats.
“Professors Breuer and Swartz are going to provide us with actual data on wing kinematics (study of objects’ motion) and how bats are able to do upside-down perching on ceilings,” Chung said. “They are going to provide a lot of very important data on the control and dynamics standpoint.”
Bats were chosen as the architectural inspiration for the project because of their unrivaled agility and maneuverability during flight.
“When a bat flaps its wings, it’s like a rubber sheet,” Hutchinson said. “It fills up with air and deforms. And then when the wing gets to the end of its motion, that rubber wing pushes the air out when it springs back into place. So you get this big amplification of power that comes just from the fact you are using flexible membranes inside the wing itself.”
Chung has already been working on the process of developing winged robotic flight. In the past, he has developed airplanes that have mimicked bird flight in the way that they glide and land softly. This project is a continuation of previous work, but bat flight is even more complex than that of birds.
By replicating bat flight patterns, Hutchinson and Chung expect the robots to have a longer battery power than rotorcraft robots, such as quadcopters and helicopters, because of their ability flap and glide instead of relying on constantly rotating propellers.
“We think we can build a dynamic structure that takes advantage of the flapping wing flight in a clever way to make it low-power,” Hutchinson said. “Also, you can imagine bats locking their wings and gliding. In principle, you can put one up in the air and have it circle around for a long time without spending much power at all. A quad rotor always has to be burning energy to stay in the air.”
It’s possible their robotic bats will be safer than other alternatives, as well. The speed with which the blades rotate on quadrotors poses a threat to workers on construction sites and people in general. Chung hopes that by implementing soft-winged robotic flight, human collisions with the robots wouldn’t cause injury in the same way a collision with a quad rotor would.
The team believes that this project has the potential revolutionize the industry of aerial robotics, and its functionality is not just limited to construction sites. Bat-inspired robotic flight has the possibility of being expanded into drone enabled package delivery, and various other systems.
“We think we can bring many benefits to robotics by using this biologically inspired architecture,” Hutchinson said. “We mean to make a robot that can have the same advantages in terms of performance, agility, and lifetime of flight as the biological thing.”