Scientists have mounted a sensor technology on robots to give them greater sensitivity and dexterity to help them manipulate small household items precisely. Eight years ago, Ted Adelson's research group at Massachusetts Institute of Technology (MIT) unveiled the sensor technology — called "GelSight" — which uses physical contact with an object to provide a detailed three-dimensional(3-D) map of its surface.
"(The system) has coloured lights at different angles, and then it has this reflective material, and by looking at the colours, the computer... can figure out the 3-D shape of what that thing is," Adelson explained. In the new research, two teams from MIT mounted the GelSight sensors on the grippers of robotic arms, which enabled the robot to determine precisely where it has grasped an item, for example, a small screwdriver.
The robot then could also remove the screwdriver as well as insert it back into a slot, even while the gripper blocked the screwdriver from the robot's camera. The results were presented at the International Conference on Robotics and Automation held in Stockholm. While Adelson's group used the data from the "GelSight" sensor to enable a robot to judge the hardness of the surfaces it touches, the other, Russ Tedrake's Robot Locomotion Group used the sensor to enable a robot to manipulate smaller objects than was previously possible.
For an autonomous robot, gauging objects' softness or hardness is essential to decide not only where and how hard to grasp them but how they would behave when moved, stacked, or laid on different surfaces. Tactile sensing could also aid robots in distinguishing objects that look similar. These are crucial abilities that robots require to manipulate small household items precisely, the scientists said.