A group of Chinese roboticists has developed a compact and dexterous robot hand, capable of a broad range of actions but also robust enough to withstand significant impact forces.
Their creation will continue to function, even in some of the most unpredictable and unstructured environments, say researchers from the Harbin University of Technology.
Engineering robots sophisticated enough to match the complexity of the human hand has become somewhat of a holy grail in the industry, with only marginal successes recorded.
Early examples of robotic hands, commonly referred to as “end-effectors”, were designed to perform very limited actions, for example, holding and releasing objects.
Fabricating anything with a more diverse range of motions has remained largely impractical. Researchers have found that end-effectors lose their strength and durability when the mechanism incorporates more moving parts.
The human hand achieves its broad range of motion because of the network of tendons and muscles that can stiffen and relax whenever engaged.
A robot mimics this through a system of variable stiffness actuators. The actuators are essentially the components of a mechanism responsible for movement.
Trying to match the hand’s complexity would require so many actuators, sensors, wiring and other materials that the size and weight of the device would become too bulky and cumbersome to function.
However, the Harbin Institute research team claims to have overcome these obstacles by developing what it calls an “antagonistic variable stiffness finger mechanism”.
The team’s research paper published in the journal, Frontiers of Mechanical Engineering, describes the novel system as using gear transmissions to actuate in place of the often employed cable-driven mechanism.
The resulting robot hand can cope with sizable impact forces and maintain functionality, while remaining suitably compact.
Constructed from a combination of 3D-printed materials and lightweight alloys, each robotic finger weighs 480 grams, according to a peer-reviewed study.
Research contributor, Yiwei Liu, described the prototype robot as performing well in areas like durability, grasping, power and manipulation.
Professor Liu and his team would seek to improve the robot’s stiffness adjustment range and continue to slim down the resulting models.
A complete and dexterous robotic hand, capable of performing multiple tasks in an unstructured environment, is the ultimate goal, according to Liu.