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Robotic Dexterous Manipulation via Anisotropic Friction Modulation using Passive Rollers

Ethan Fisk, Taeyoon Lee, Shenli Yuan

Abstract

Controlling friction at the fingertip is fundamental to dexterous manipulation, yet remains difficult to realize in robotic hands. We present the design and analysis of a robotic fingertip equipped with passive rollers that can be selectively braked or pivoted to modulate contact friction and constraint directions. When unbraked, the rollers permit unconstrained sliding of the contact point along the rolling direction; when braked, they resist motion like a conventional fingertip. The rollers are mounted on a pivoting mechanism, allowing reorientation of the constraint frame to accommodate different manipulation tasks. We develop a constraint-based model of the fingertip integrated into a parallel-jaw gripper and analyze its ability to support diverse manipulation strategies. Experiments show that the proposed design enables a wide range of dexterous actions that are conventionally challenging for robotic grippers, including sliding and pivoting within the grasp, robust adaptation to uncertain contacts, multi-object or multi-part manipulation, and interactions requiring asymmetric friction across fingers. These results demonstrate the versatility of passive roller fingertips as a low-complexity, mechanically efficient approach to friction modulation, advancing the development of more adaptable and robust robotic manipulation.

Robotic Dexterous Manipulation via Anisotropic Friction Modulation using Passive Rollers

Abstract

Controlling friction at the fingertip is fundamental to dexterous manipulation, yet remains difficult to realize in robotic hands. We present the design and analysis of a robotic fingertip equipped with passive rollers that can be selectively braked or pivoted to modulate contact friction and constraint directions. When unbraked, the rollers permit unconstrained sliding of the contact point along the rolling direction; when braked, they resist motion like a conventional fingertip. The rollers are mounted on a pivoting mechanism, allowing reorientation of the constraint frame to accommodate different manipulation tasks. We develop a constraint-based model of the fingertip integrated into a parallel-jaw gripper and analyze its ability to support diverse manipulation strategies. Experiments show that the proposed design enables a wide range of dexterous actions that are conventionally challenging for robotic grippers, including sliding and pivoting within the grasp, robust adaptation to uncertain contacts, multi-object or multi-part manipulation, and interactions requiring asymmetric friction across fingers. These results demonstrate the versatility of passive roller fingertips as a low-complexity, mechanically efficient approach to friction modulation, advancing the development of more adaptable and robust robotic manipulation.

Paper Structure

This paper contains 23 sections, 14 equations, 8 figures, 2 tables.

Figures (8)

  • Figure 2: Prototype fingertips with pivotable, brakeable rollers mounted on a Robotiq 2F-85 Adaptive Gripper.
  • Figure 3: A CAD model of the proposed roller module: (a) An exploded view showing the separation between brake and roller. (b) An exploded view of the rollers. (c) An exploded view of the brake mechanism. (d) A complete view with call-outs for relevant dimensions.
  • Figure 4: Kinematic model of a general object under antipodal grasp by the proposed gripper with two arbitrary rolling axes, including environmental contact.
  • Figure 5: Friction Test Apparatus (Top View)
  • Figure 6: Object Manipulation with a Unilateral External Constraint. Red arrows indicate gripper actions, while green arrows indicate object motion. (A) Planar Object Translation. (B) Cylindrical Object Rotation.
  • ...and 3 more figures