  To design a general-purpose assembly robot system that can handle objects of
various shapes, we propose a soft jig that fits to the shapes of assembly
parts. The functionality of the soft jig is based on a jamming gripper
developed in the field of soft robotics. The soft jig has a bag covered with a
malleable silicone membrane, which has high friction, elongation, and
contraction rates for keeping parts fixed. The bag is filled with glass beads
to achieve a jamming transition. We propose a method to configure parts-fixing
on the soft jig based on contact relations, reachable directions, and the
center of gravity of the parts that are fixed on the jig. The usability of the
soft jig was evaluated in terms of the fixing performance and versatility for
various shapes and postures of parts.
