Citation: Kim, M.-G.; Kim, J.; Chung,
S.Y.; Jin, M.; Hwang, M.J.
Robot-Based Automation for Upper
and Sole Manufacturing in Shoe
Production. Machines 2022, 10, 255.
https://doi.org/10.3390/
machines10040255
Academic Editor: Dan Zhang
Received: 20 February 2022
Accepted: 30 March 2022
Published: 1 April 2022
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Article
Robot-Based Automation for Upper and Sole Manufacturing in
Shoe Production
Min-Gyu Kim
1
, Juhyun Kim
1
, Seong Youb Chung
2
, Maolin Jin
1,
* and Myun Joong Hwang
3,
*
1
Korea Institute of Robotics & Technology Convergence, Pohang 37553, Korea;
mingyukim@kiro.re.kr (M.-G.K.); myearch@kiro.re.kr (J.K.)
2
Department of Mechanical Engineering, Korea National University of Transportation, Chungju 27469, Korea;
sychung@ut.ac.kr
3
Department of Mechanical and Information Engineering, University of Seoul, Seoul 02504, Korea
* Correspondence: mulimkim@kiro.re.kr (M.J.); mjhwang@uos.ac.kr (M.J.H.); Tel.: +82-2-6490-2389 (M.J.H.)
Abstract:
(1) Background: Conventional shoe manufacturing involves many processes that most
workers avoid because of loud noises and harmful environments. Therefore, a robot-based shoe
manufacturing system is needed to implement an automated process. (2) Aim: We propose a new
robot-based shoe manufacturing automation system that includes an automatic robotic solution for
replacing the manual manufacturing processes of the upper and sole. (3) Methods: For the upper
manufacturing process, a new trajectory acquisition system with a digitizer and a shoe last turning
device is proposed. A method to plan the robot’s tool path for roughing and cementing by industrial
robot manipulators is also presented. For the sole manufacturing process, we adopted an industrial
robot manipulator with a 3-D scanning system and a cementing tool. A trajectory generation
algorithm for cementing the outer and inner sides of the sole by transforming 3-D information
of the sole into a 6-D posture for the robot is proposed. (4) Results: All developed systems and
proposed algorithms are applied to an automated production testbed, and their performances are
experimentally verified. (5) Conclusions: The proposed system and methods can be applied for
upper and sole manufacturing processes according to evaluation experiments in a demonstrative
production line.
Keywords: robot-based shoe manufacturing; robot path generation; smart manufacturing
1. Introduction
Traditionally, the shoe manufacturing process has been labor intensive and required
significant manual work by skilled workers. Conventional shoe manufacturing plants
involve many processes that most workers avoid because of loud noises and hazardous
substances. This unsatisfactory work environment suppresses the influx of new manpower
and, at the same time, causes difficulties in retaining skilled manpower and an aging
worker problem. In recent years, as footwear has become a popular fashion accessory, small-
scale production of footwear has started in the industry, allowing it to cope with various
and changing customer preferences. Compared with traditional shoe manufacturing
plants, modern shoe factories must provide efficient and effective production with flexible
manufacturing cells. Smart factory in Industry 4.0 is required to respond to a small quantity,
multi-product flexible production system [
1
]. In a smart factory, automated processes using
robots and systematic production using information management systems such as RFID
are possible.
According to the structure of a shoe, the shoe manufacturing process can be broadly
divided into an upper manufacturing process, a sole manufacturing process, and an assem-
bly process, in which the upper part and the sole are bonded and shipped. In the manual
production lines of upper and sole manufacturing, the worker draws a gauge line on the
upper part with a white pen to mark the boundary line of the roughing and cementing
Machines 2022, 10, 255. https://doi.org/10.3390/machines10040255 https://www.mdpi.com/journal/machines
