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Perception, Control and Hardware for In-Hand Slip-Aware Object Manipulation with Parallel Grippers

Gabriel Arslan Waltersson, Yiannis Karayiannidis

TL;DR

This work addresses the challenge of in-hand manipulation with slip by introducing a sensorized parallel gripper that relies solely on in-hand sensing. It integrates high-bandwidth force control with planar velocity sensing to rapidly estimate friction and contact properties at pickup and employs four simple slip-aware controllers (slip-avoidance, linear slip, rotational slip, and hinge mode) to achieve gravity-assisted manipulation of objects with flat surfaces. The system is validated on a UR10, demonstrating fast, stable grasp force regulation, accurate planar velocity estimation, and robust slip control across diverse objects and surfaces, including 2 s contact-property estimation and 120 Hz control loops. The findings highlight the practical potential of in-hand sensing for expanding the manipulation capabilities of parallel grippers, enabling more versatile and safer handling, multi-arm coordination, and future planning for slip-aware manipulation.

Abstract

Dexterous in-hand manipulation offers significant potential to enhance robotic manipulator capabilities. This paper presents a sensori-motor architecture for in-hand slip-aware control, being embodied in a sensorized gripper. The gripper in our architecture features rapid closed-loop, low-level force control, and is equipped with sensors capable of independently measuring contact forces and sliding velocities. Our system can quickly estimate essential object properties during pick-up using only in-hand sensing, without relying on prior object information. We introduce four distinct slippage controllers: gravity-assisted trajectory following for both rotational and linear slippage, a hinge controller that maintains the object's orientation while the gripper rotates, and a slip-avoidance controller. The gripper is mounted on a robot arm and validated through extensive experiments involving a diverse range of objects, demonstrating the architecture's novel capabilities for manipulating objects with flat surfaces.

Perception, Control and Hardware for In-Hand Slip-Aware Object Manipulation with Parallel Grippers

TL;DR

This work addresses the challenge of in-hand manipulation with slip by introducing a sensorized parallel gripper that relies solely on in-hand sensing. It integrates high-bandwidth force control with planar velocity sensing to rapidly estimate friction and contact properties at pickup and employs four simple slip-aware controllers (slip-avoidance, linear slip, rotational slip, and hinge mode) to achieve gravity-assisted manipulation of objects with flat surfaces. The system is validated on a UR10, demonstrating fast, stable grasp force regulation, accurate planar velocity estimation, and robust slip control across diverse objects and surfaces, including 2 s contact-property estimation and 120 Hz control loops. The findings highlight the practical potential of in-hand sensing for expanding the manipulation capabilities of parallel grippers, enabling more versatile and safer handling, multi-arm coordination, and future planning for slip-aware manipulation.

Abstract

Dexterous in-hand manipulation offers significant potential to enhance robotic manipulator capabilities. This paper presents a sensori-motor architecture for in-hand slip-aware control, being embodied in a sensorized gripper. The gripper in our architecture features rapid closed-loop, low-level force control, and is equipped with sensors capable of independently measuring contact forces and sliding velocities. Our system can quickly estimate essential object properties during pick-up using only in-hand sensing, without relying on prior object information. We introduce four distinct slippage controllers: gravity-assisted trajectory following for both rotational and linear slippage, a hinge controller that maintains the object's orientation while the gripper rotates, and a slip-avoidance controller. The gripper is mounted on a robot arm and validated through extensive experiments involving a diverse range of objects, demonstrating the architecture's novel capabilities for manipulating objects with flat surfaces.

Paper Structure

This paper contains 29 sections, 32 equations, 36 figures, 15 tables, 2 algorithms.

Table of Contents

  1. Introduction
  2. Related Work
  3. Tactile Sensors
  4. Grippers
  5. Slip Control and Estimation
  6. Contributions and Overview
  7. Gripper design
  8. Hardware
  9. Grasp Force Control
  10. Velocity sensor design
  11. Planar Velocity Sensor
  12. Velocity Sensor Calibration
  13. Estimation of contact properties
  14. Controlled slippage
  15. Slip-Avoidance
  16. ...and 14 more sections

Figures (36)

  • Figure 1: Picture of the custom gripper mounted with F/T and relative velocity sensors.
  • Figure 2: Overview of the architecture with the inner and outer control loops, the mechanical connections are marked with dashed lines and information pathways are marked as solid lines.
  • Figure 3: Gripper viewed from the side with the overall dimensions.
  • Figure 4: The internal components of the gripper.
  • Figure 5: The communication inside the gripper and with the computer.
  • ...and 31 more figures