The ModQuad Gripper is a flying gripper based on cuboid modular robots invented by Bruno Gabrich, David Saldana, Vijay Kumar and Mark Yim from the GRASP (General Robotics, Automation, Sensing & Perception) Laboratory of the University of Pennsylvania.
The video explains the grippers components, how it operates, and a sample application of its use. It is a novel wire platform and not a traditional quadrotor, which gives it the ability to grasp objects in unusual forms. The platform is based on four modules that cooperatively fly in the air using the newly centralized controller.
Each module is based in a quadrotor and modular cage made out of carbon fiber rods, ABS 3-D printed connectors, and cylindrical magnets. The flying gripper is conceived by connecting the four modules by their vertical edges. The four attached modules result in a 1-DPF (Degree of freedom) gripper for bar linkage. In order to close the gripper, a pair of modules rotates clockwise, and the other pair rotates counterclockwise.
The main application of the gripper is transporting objects. The video is able to show one of the lab’s experiments where the gripper is able to move a cup from a conic support and deposit it to a trash can. The robot aligns itself to the target and initiates the closing motion to grasp the cup. The researchers used a centralized trajectory controller to follow a set of waypoints including the desired aperture angle for each waypoint. With the object grasped, it can now be transported through the environment, and once aligned to the trashcan, it releases the cup by sending the desired aperture angle.