  Reinforcement Learning (RL) has shown great promise for efficiently learning
force control policies in peg-in-hole tasks. However, robots often face
difficulties due to visual occlusions by the gripper and uncertainties in the
initial grasping pose of the peg. These challenges often restrict
force-controlled insertion policies to situations where the peg is rigidly
fixed to the end-effector. While vision-based tactile sensors offer rich
tactile feedback that could potentially address these issues, utilizing them to
learn effective tactile policies is both computationally intensive and
difficult to generalize. In this paper, we propose a robust tactile insertion
policy that can align the tilted peg with the hole using active inference,
without the need for extensive training on large datasets. Our approach employs
a dual-policy architecture: one policy focuses on insertion, integrating force
control and RL to guide the object into the hole, while the other policy
performs active inference based on tactile feedback to align the tilted peg
with the hole. In real-world experiments, our dual-policy architecture achieved
90% success rate into a hole with a clearance of less than 0.1 mm,
significantly outperforming previous methods that lack tactile sensory feedback
(5%). To assess the generalizability of our alignment policy, we conducted
experiments with five different pegs, demonstrating its effective adaptation to
multiple objects.
