Thursday, May 31, 2012

Robotiq 2-Finger Adaptive Gripper

The Robotiq 2 finger adaptive gripper, previously covered by our friends at Hizook, is now commercially available.

The gripper can be controlled through a variety of interfaces including EtherNet/IP, TCP/IP, DeviceNet, CANopen, EtherCAT, and RS232. On the software side, all of the major vendors of industrial robot arms are supported and Robotiq provides excellent documentation if you need to write your own drivers. As for ROS drivers, according to Robotiq they "are looking to develop something about it, but no timeline has been set yet for this project."

The gripper has mechanical passive compliance that provides self-centering and allows parts to be removed from the gripper when power is removed. The drive mechanism is also self-locking reducing power consumption and ensuring that parts are not dropped if power is shut off. Full position control and force sensing capabilities are also provided.

From the Robotiq manual, "It is important to note that a fingertip grip can only be performed when the fingers touch the object with the distal phalanxes first. Inversely, for an encompassing grip, the fingers must touch the object with the proximal or the lower section of the distal phalanxes first." This indicates that the design takes advantage of the configuration of the 5-bar linkage that degenerates into a 4-bar parallel linkage. The mechanical toggle is shown in the diagram below, where the green lines show the linkages and the red X shows the pivots which can not rotate.
I am unsure about the patent-pending status mentioned by Hizook. INAL, but IAME (I'm A Mechanical Engineer) and I don't believe the parallel to enclosing grasp adaptive mechanism is patentable as it seems obvious and I feel like there is prior art (if I was looking for prior art, I would look at clamp designs), but maybe there is more to it than that and who knows given the things that get patented these days.

The Robotiq 2-finger adaptive gripper looks to provide a excellent solution for a variety of grasping applications. It would be interesting to see the payback period in a flexible manufacturing environment where an adaptive gripper could reduce the need for tool changes.

The Robotiq blog has more here and here.

No comments: