Compliant shape adaptive chicory gripping

for robotic sorting processes

Master thesis (2020)

Authors

T. Hester Mechanical Engineering

Contributors

G. Smit Medical Instruments & Bio-Inspired Technology - Mechanical, Maritime and Materials Engineering (supervisor 1)
P. Breedveld Medical Instruments & Bio-Inspired Technology - Mechanical, Maritime and Materials Engineering (supervisor 2)
Mohammad J. Mirzaali Biomaterials & Tissue Biomechanics - Mechanical, Maritime and Materials Engineering (supervisor 2)
Faculty
Mechanical Engineering
Copyright: © 2020 Thomas Hester
Sorting Robot Adaptive 3D Printing Processes Compliant Gripping Shape Grasping Additive manufacturing Gripper Chicory Robotic Grip End effector
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Published Date

27-08-2020

Language

English

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Faculty

Mechanical Engineering

Abstract

This thesis contains the design process of a compliant shape adaptive chicory gripper for robotic sorting processes. The robotic sorting line consists of an input and output conveyor-belt. The input line contains unsorted chicories which are scanned by a robotic vision system. Overhead FlexPicker robots, equipped with chicory grippers, sort the chicories size by size onto the output line. The output line can contain a transportation crate or flowpack in which the chicories will be packed and shipped after sorting. Chicories are vulnerable for internal and external damages when touching the outer skin which makes robotic sorting difficult. The acceleration forces performed by the robot requires a strong but gentle grip on the chicory without any damaging marks. By designing a specific compliant shape adaptive gripper, sorting can be done faster, cheaper and more accurate than manual sorting. Current patents, academic literature or business applications had no solution for this chicory gripping problem. The design process for a suitable gripper started with an analysis of current patents and literature within compliant gripping in general. This provided insights in the the possibilities of compliant gripping. Based on the design requirements for the robot sorting setup, several concepts are obtained and selected. The concepts have been translated into four working gripper prototype layouts which are evaluated on force and damage requirements. Based on the results of these experiments, a first iteration prototype was made. Three additional optimizing iterations were needed to result in a prototype which reached the damage and force requirements. Further evaluation of this prototype proved a sufficient performance on robustness, endurance, operational speed and food grade requirements. The iteration 4 prototype reached therefore 17 of the total 19 gripper design requirements. To be able to accomplish the two remaining requirements, several recommendations are provided for a final gripper end product which is ready for industrial application.