Soft robotic hands are inherently safer and more compliant in robot-environment interaction than rigid manipulators, but their flexibility and versatility still need improving. In this article, a gesture adaptive soft-rigid robotic hand is proposed. The robotic hand has three pneumatic two-segment fingers. Each finger segment is driven independently for flexible gesture adjustment to match up with different object shapes. The palm is constructed by a rigid skeleton driven by a soft pneumatic spring. It provides a firm support, large workspace, and independent force control for the fingers. Geometry model of the robotic hand is established, based on which a grasping gesture optimization algorithm is adopted. The fingers achieve optimal contact with objects by performing maximal curving similarity with the object outlines. Experiment shows that the soft-rigid robotic hand provides adaptive and reliable grasping for objects of different sizes, shapes, and materials with optimized gestures.
Keywords: adaptive grasping; compliant grasping; gesture optimization; soft robotic hand.