The team of researchers from CSAIL director Daniela Rus’ Distributed Robotics Lab demonstrated that their robotic hand can lift and handle objects as delicate as an egg and as thin as a piece of paper. Its three fingers house sensors that can estimate the size and shape of an object accurately enough to identify it from a set of multiple items.
“Robots are often limited in what they can do because of how hard it is to interact with objects of different sizes and materials,” Rus says. “Grasping is an important step in being able to do useful tasks; with this work we set out to develop both the soft hands and the supporting control and planning systems that make dynamic grasping possible."
The gripper is part of a larger body of work by Rus’ lab aimed at showing the value of so-called ‘soft robots’ made of unconventional materials such as silicone, paper, and fibre.
Researchers say that soft robots have a number of advantages over ‘hard’ robots, including the ability to handle irregularly-shaped objects, squeeze into tight spaces, and readily recover from collisions.
However, one downside to their extra flexibility is that they often have difficulty accurately measuring where an object is, or even if they have successfully picked it up at all.
To combat this, the CSAIL team also incorporated ‘bend sensors’ into the design. When the gripper hones in an object, the fingers send back location data based on their curvature. Using this data, the robot can pick up an unknown object and compare it to existing clusters of data points that represent past objects.
In the future, Rus says the team plans to put more time into improving and adding more sensors that will allow the gripper to identify a wider variety of objects.
“If we want robots in human-centred environments, they need to be more adaptive and able to interact with objects whose shape and placement are not precisely known,” Rus says. “Our dream is to develop a robot that, like a human, can approach an unknown object, big or small, determine its approximate shape and size, and figure out how to interface with it in one seamless motion.”
