Most drones are designed for passive applications — such as filming or aerial mapping — instead of active applications like manipulating or carrying items. There are two reasons for that: drones have a limited payload that restricts what they can carry, and it’s difficult to achieve the precision necessary to reliably interact with the world directly. But a team of researchers from the University of Auckland have developed new robotic grippers that could make it easier for drones to grasp and carry items.
The research team has developed two robotic gripper designs, both of which are intended to be mounted underneath a typical multirotor drone. The first has a number of friction pads that hang below semi-flexible supports. A wire runs through each of those pads. That wire is wrapped around a motorized spool, and spinning the motor shortens the wire and causes the friction pads to squeeze together. This unique gripper mechanism is ideal for grabbing a wide range of objects, because the pads can conform to a variety of different shapes.
The second robotic gripper design looks more conventional, and has three fingers — two on one side of the “hand” and one on the other side. The goal of this design is speed. A distance sensor in the center of the gripper registers when an object is nearby. When that object is detected, the fingers snap shut. This is using just two actuators, but those have been geared to operate as quickly as possible. The team says the gripper can close in just 93 milliseconds. That capability makes this gripper perfect for snatching thrown objects out of the air. It even allows a drone to clamp down on structures in order to perch like a bird does. Both designs represent the potential for drones to actively interact with their environments in practical ways.