Small quadcopter drones, or micro-air vehicles (MAVs), have very short battery life. So, if they can “perch” somewhere rather than hovering in the air, more power to them. A new gripper mechanism has been designed with that in mind.
Developed by a team of engineers at Colorado State University, the device is installed on top of a third-party MAV. It has vertical propulsion-like bearings in the center, which are mechanically connected to two folded arms raised diagonally, one on either side. At the top end of each arm there is an in-facing gripper bearing.
When the MAV flies to the bottom of a horizontal object such as a tree branch, pipe or fence, the force of the collision pushes the bearing down. This in turn causes both arms to fold in, grasping the object, and holding the drone in place. The propeller motor can then be turned off until it has to fly again.
Depending on the diameter of the object, the arm can grasp it on both sides with a gripper bearing, or circle and meet on top. In both cases, the act of grasping is completely mechanical, does not require electricity. A small amount of energy is required to move the arm back to the back, when it is time to disembark and resume the flight.
“Although our bistable gripper is used with palm-sized quadcopters, design strategies can also be applied to large-size MAVs for energy-efficient perching and air gripping,” said team member Dr. Jianguo Zhao.
Gripper is shown in the video below, and is described in a paper recently published in the journal IEEE Explore.