Ryuugo Mochizukⁱ¹, Yuya Nishida², Kazuo Ishii^2
1Center for Socio-Robotic Synthesis, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsuku, Kitakyushu, 808-0196, Fukuoka, Japan ²Department of Human Intelligence Systems, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsuku, Kitakyushu,808-0196, Fukuoka, Japan
pp. 343–348
ABSTRACT
In food industry, shortage of workers is one of a serious problem. Automation of food handling is a critical nowadays. To alleviate the damage caused by food picking operation by robotic hand, we propose non-contact acoustic impedance estimation with ultrasonic wave, which should be preceded before the picking for optimization of grasp stiffness. We assume the correlation between hardness and acoustic impedance. That is, the harder the medium is, the larger the impedance should be. As cooked food, the unevenness of hardness should be considered. We made samples with media of different acoustic impedances, and experimented with ultrasonic to find the relation between reflection coefficient and hardness. As the result, reflection coefficient increased by 0.03-0.15 at the boundary of two media as the bottom medium is switched from urethane to Aluminum.

ARTICLE INFO
Article History
Received 27 November 2021
Accepted 01 February 2023

Keywords
Acoustic impedance
Ultrasonic
Hardness estimation
Internal reflection
Reflection coefficient

JRNAL9407

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