A Sensorized Hybrid Gripper to Evaluate a Grasping Quality Based on a Largest Minimum Wrench

Wookeun Park,Seongmin Seo,Joonbum Bae,Jinhyeok Oh

doi:10.1109/lra.2020.2976312

Wookeun Park, Seongmin Seo + Show 2 more

Open Access

https://doi.org/10.1109/lra.2020.2976312

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Abstract

Soft pneumatic grippers, which are based on soft pneumatic actuators have been widely studied owing to their simple morphological structure, inherent compliance, and pliable grasp. Additionally, the integration of the soft gripper with various sensors to improve its functionality has also been extensively studied. Although the soft gripper is known to exhibit a robust grasping performance without accurate control, the grasping quality of the soft gripper has rarely been studied due to the lack of adequate embedded sensors and quality metrics of the soft gripper. Therefore, a hybrid gripper, which is a soft gripper with rigid components, was sensorized by embedding a soft force sensor and a bending sensor to evaluate the grasping quality. Furthermore, a new grasping quality metric for a soft gripper was proposed, which calculates the largest minimum wrench of a convex hull in the wrench space. The proposed grasping quality metric was experimentally verified, and a real-time program was developed to evaluate the grasping quality.

Highlights

R ECENTLY, soft pneumatic grippers (SPGs), which offer a more compliant bending motion than rigid robots owing to their simple morphological structure and higher degree of freedom, have been actively developed [1]–[3]
soft pneumatic actuators (SPAs) have been reinforced by fiber, fabric, and integration with rigid and soft materials to realize enhanced fingertip forces [1]–[5]
The grasping posture based on the wrench, which indicates the force and torque applied to the grasped object, should be evaluated how well the grasp resist to external wrenches in the wrench equilibrium

Summary

Introduction

R ECENTLY, soft pneumatic grippers (SPGs), which offer a more compliant bending motion than rigid robots owing to their simple morphological structure and higher degree of freedom, have been actively developed [1]–[3]. To enhance their grasping performance such as actuation speed and finger force, soft pneumatic actuators (SPAs) have been developed in many ways [1]–[5]. Different chamber shapes, such as the fast pneumatic network (PneuNet), have been investigated for improved actuation speed [6].

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