Engineers at MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) have developed a pair of robotic grippers capable of manipulating cables, string, rope, wire, and other cordage that closely mimics the way humans handle flexible objects. Tying knots, plugging in headphones and USB cables are natural for us, as we can use the dexterity and sense of touch in our hands and fingers to accomplish those feats, but for robots, that’s a near impossible feat, at least until now.
The researchers outfitted the soft robotic grippers using GelSight tactile sensors to manipulate freely moving cables, which are equipped with high-resolution cameras embedded in soft rubber. The system is comprised of two grippers — one stationary and the other connected to a free-moving robotic arm, with both working in tandem. Each gripper is outfitted with opposing fingers, which are quick-moving, providing somewhat nimble real-time positions with applied force and position to handle cordage.
The engineers embedded the vision-based GelSight sensors on the tips of each finger, which allows the grippers to estimate the orientation and pose of the cable between the fingers, and measure the frictional forces as the cable slides through them. Teamwork comes into play, as two controllers function in parallel, with one modulating the grip, while the other adjusts it poses to help keep the cable within its grasp. In a demonstration, one gripper successfully followed a USB cable starting from a random position, while the other moved “hand-over-hand” to locate its end.
A second demonstration showed the system successfully insert a headphone cable into a cellphone jack in much the same fashion as we humans. The team plans on further developing their robotic grippers to perform new feats, such as routing cables and even manipulating cables in the auto industry at some point in the future.
More details can be found in the researchers' paper.