• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.18 no.4
• /
• pp.87-92
• /
• 2019

In this paper, a closed hydroponics device was designed and fabricated to grow and harvest plants in a small space for safe consumption, which enables horticultural activities that are difficult to perform due to space constraints from urbanization. This device also aimed to minimize the air pollution of crops. To obtain data for the optimal growth conditions for crops in this intelligent plant-growing system, sensors were used to measure and control the growth conditions. To investigate the optimal growth conditions, blue lettuce and crown daisy were selected as representative crops. The growth rates were comparatively analyzed through four experiments for each plant. This hydroponics device was used to collect data on growth rates that are altered depending on cultivation conditions, which can then be used to study methods to control the growth rate of crops.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.21 no.8
• /
• pp.32-42
• /
• 2022

Asymptotic tracking of a non-minimum phase nonlinear system has been a popular topic in control theory and application. In this paper, we propose a new control scheme to achieve asymptotic output tracking in anon-minimum phase nonlinear system for periodic trajectories through an iterative learning control with the stable inversion. The proposed design method is robust to parameter uncertainties and periodic external disturbances since it is based on iterative learning. The performance of the proposed algorithm was demonstrated through the simulation results using a typical non-minimum nonlinear system of an inverted pendulum on a cart.

• Journal of the Korean Society of Industry Convergence
• /
• v.20 no.3
• /
• pp.245-256
• /
• 2017

In this study, we describe a new approach to real-time implementation of working path control for the forging and casting manufacturing process by vertical type articulated robot system. The proposed control scheme is simple in structure, fast in computation, and useful for real-time control of factory automation based on robot system. Moreover, this scheme does not require any accurate parameter information, nor values of the uncertain parameters and payload variations. Reliability of the proposed controller is proved by simulation and experimental results for robot manipulator consisting of arm with six degrees of freedom under the variation of payloads and tracking trajectories in Cartesian space and joint space. The vertical type articulated robot manipulator with six axes made in SMEC Co., Ltd. has been used for real-time implementation test to illustrate the enhanced working path control performance for unmanned automation of the forging and casting manufacturing process.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.8 no.4
• /
• pp.69-75
• /
• 2009

Recently developed automotive components are getting lighter providing a higher fuel efficiency and performance. Following the current trend, this study proposes a structural optimization method for the lower control arm installed at the front side of a Vehicle. Lightweight design of lower control arm can be achieved through design and material technology. In this research, the shape of lower control arm was determined by applying the optimization technology and aluminum was selected as a steel-substitute material. Strength performance is the most important design requirement in the structural design of a control arm. This study considers the static strength in the optimization process. For the optimum design, the durability analysis is performed to predict its fatigue life. In this study, the kriging interpolation method is adopted to obtain the minimum weight satisfying the strength constraint. Optimum designs are obtained by the in-house program, EXCEL-Kriging. Also, based on the optimum model obtained for the static strength, the optimization of Index of Fatigue Durability is carried out to get th optimum fatigue performance.

• Journal of the Korea Safety Management & Science
• /
• v.12 no.2
• /
• pp.65-73
• /
• 2010

In an automated industry PLC plays a central role to control the manufacturing system. Therefore, fault free operation of PLC controlled manufacturing system is essential in order to maximize a firm's productivity. On the contrary, distributed nature of manufacturing system and growing complexity of the PLC programs presented a challenging task of designing a rapid fault finding system for an uninterrupted process operation. Hence, designing an intelligent monitoring, and diagnosis system is needed for smooth functioning of the operation process. In this paper, we propose a method to continuously acquire a stream of PLC signal data from the normal operational PLC-based manufacturing system and to generate diagnosis model from the observed PLC signal data. Consequently, the generated diagnosis model is used for distinguish the possible abnormalities of manufacturing system. To verify the proposed method, we provided a suitable case study of an assembly line.

• Journal of Korean Society for Quality Management
• /
• v.22 no.1
• /
• pp.188-204
• /
• 1994

Most of computer-aided process planning(CAPP) systems have been developed to automate the process planning function. In this paper, we describe an analytical model for a CAPP system in order to improve the performance of production system in flexible manufacturing systems(FMSs) for computer intergrated manufacturing(CIM) architecture. This paper proposes an optimal process planning that minimizes the load time by minimizing the cycle time and the number of workstations using Kang and Hahm's heuristic approach so as to improve the performance of production system under the batch production of discrete products. We also perform simulation using SIMAN language to campare the line utilization of each for various product types. The proposed algorithm can be implemented in existing FMSs for on-line control of product quantity using programmable logic controllers(PLC) and communication devices.

• Journal of Industrial Technology
• /
• v.19
• /
• pp.321-329
• /
• 1999

An automated manufacturing process mechanism for string musical instruments has been designed in this study. In contrast to other manufacturing products, classical string instruments try to preserve their traditional design shapes even in these days and involve variety of wood working(carpentry) characteristics including highly skilled curved surfaces treatments. Great efforts have been put to develop an integrated and automated system for improved product quality and process control, reduced physical labors, better safety etc. They, however, have been limited to devise jigs and tools with regard to selected processes due to lack of technology and research man-powers. We carefully examined the products and process characteristics, and an automated mechanism which overcome prevailing drawbacks has been derived.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.17 no.3
• /
• pp.155-162
• /
• 2018

Delta robots are usually used for industrial manufacturing, but heavy weight and expensive price have been obstacles to rapid propagation of robots in the field. The goal of this research is to make light-weight and price-competitive delta robots. To reduce the weight, we used plastic material for the arm link, and to reduce the price, we used a step-motor as the main actuator. First we formulated the equations of inverse kinematics for the designed delta robot and then verified these equations by using multibody-dynamics simulation. An algorithm of motion control was developed and applied to the motion-processing unit using a timer-interrupt of 8 milliseconds. Finally, we tested the performance of the new delta robot by checking its control of motion along line segments.

• Journal of the Korean Society of Industry Convergence
• /
• v.22 no.2
• /
• pp.137-146
• /
• 2019

This study proposed a new technique to control of mobile robot based on voice command for (Human-Robot Cooperative operation in manufacturing precess). High performance voice recognition and control system was designed In this paper for smart factory. robust voice recognition is essential for a robot to communicate with people. One of the main problems with voice recognition robots is that robots inevitably effects real environment including with noises. The noise is captured with strong power by the microphones, because the noise sources are closed to the microphones. The signal-to-noise ratio of input voice becomes quite low. However, it is possible to estimate the noise by using information on the robot's own motions and postures, because a type of motion/gesture produces almost the same pattern of noise every time it is performed. In this paper, we describe an robust voice recognition system which can robustly recognize voice by adults and students in noisy environments. It is illustrated by experiments the voice recognition performance of mobile robot placed in a real noisy environment.

• Journal of the Korean Society for Precision Engineering
• /
• v.19 no.8
• /
• pp.16-25
• /
• 2002