FINE TACTILE MANIPULATION VIA FORCE-GUIDED VISION-FREE CONTROLLER FOR PEG INSERTION AND DISENGAGEMENT

Abstract

Executing the Peg-In-Hole operation in variable environments continues to pose a challenge for autonomous robots. Most popular way of solving this task is typically via visual feedback. However, alternative sensing methods are critical in environments where visual data is limited or unreliable, and in the case of occlusion by end-effector. This paper presents a novel force-guided vision-free controller fitted for fine tactile manipulation, specifically peg insertion and extraction tasks using a USB stick. By utilizing force feedback, the controller operates without visual input, relying solely on tactile sensing for precise manipulation. The system processes real-time force and torque data from the manipulator to guide the peg’s alignment and establish initial insertion into a hole. To enable further fine insertion tactile feedback is used. Specifically, we focus on manipulating the peg with a parallel gripper integrated with a tactile sensor. The sensor data is processed to track in-hand rotations of the peg’s pose, which is then fed back to the robot controller. This feedback enables the system to compensate for variations in peg orientation and end-point position during task execution. After successful insertion, the wiggle movement is initiated via force control to extract the peg. The proposed approach is validated on the Franka Emika manipulator using a two-finger Robotiq 2F-85 gripper equipped with Xela capacitive-based tactile sensor arrays, each containing 16 tactile elements.