# A Dexterous Hand for Omnidirectional In-Hand Manipulation: Design, Analysis and Experimental Validation

## TL;DR

A new dexterous hand with mecanum wheels enables omnidirectional object manipulation and reduces control complexity.

## Contribution

The novel design introduces mecanum wheels at fingertips for continuous object motion without finger gaiting.

## Key findings

- The hand can manipulate objects omnidirectionally using continuous mecanum wheel rotation.
- Kinematic models for various object shapes were validated through simulations and experiments.
- The hand can be reconfigured into an omnidirectional mobile robot.

## Abstract

Traditional dexterous hands can readily grasp objects but face limitations in dexterous manipulation due to complex control systems and high actuation demands. This paper presents a novel dexterous hand designed to address these challenges. The hand consists of four fingers, each equipped with two mecanum wheels at the fingertips to allow for the omnidirectional manipulation of objects. Continuous rotation of the mecanum wheels enables unbounded motion of grasped objects without the need for finger gaiting. Object pose adjustment is achieved by controlling the rotation of mecanum wheels, thus significantly reducing operational complexity and enhancing manipulative agility. Furthermore, to address the control difficulty of multi-finger coordinated motion, a four-finger coupled mechanism is implemented, resulting in a dexterous hand with three degrees of freedom. Kinematic models of omnidirectional manipulation are established for typical geometric objects, including a flat plate, a cuboid, a sphere, and a cylinder. Simulations confirm the correctness of the kinematic models. Experimental results show that the hand can achieve omnidirectional manipulation of objects. Finally, the extended functionality of the dexterous hand is briefly presented, which allows it to be reconfigured into an omnidirectional mobile robot.