  Applying suction grippers in unstructured environments is a challenging task
because of depth and tilt errors in vision systems, requiring additional costs
in elaborate sensing and control. To reduce additional costs, suction grippers
with compliant bodies or mechanisms have been proposed; however, their
bulkiness and limited allowable error hinder their use in complex environments
with large errors. Here, we propose a compact suction gripper that can pick
objects over a wide range of distances and tilt angles without elaborate
sensing and control. The spring-inserted gripper body deploys and conforms to
distant and tilted objects until the suction cup completely seals with the
object and retracts immediately after, while holding the object. This seamless
deployment and retraction is enabled by connecting the gripper body and suction
cup to the same vacuum source, which couples the vacuum picking and retraction
of the gripper body. Experimental results validated that the proposed gripper
can pick objects within 79 mm, which is 1.4 times the initial length, and can
pick objects with tilt angles up to 60{\deg}. The feasibility of the gripper
was verified by demonstrations, including picking objects of different heights
from the same picking height and the bin picking of transparent objects.
