• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.195-204
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• 2020

To help solve the problems of how to set the optimal sawing force and the optimal controller parameters for different sawing conditions, a mathematical model of a proposed sawing system was established according to the principle of sawing force control. The conventional PID control method was then used for further research of the closed-loop control of the sawing force. Finally, through simulation and experimental research, the influence rule of the controller parameters and sawing load on the control performance and the relationships between the sawing width and controller parameters (proportion coefficient) and the sawing force setting value were obtained, from which a system scheme for intelligent sawing control of a band sawing machine was proposed. The research shows that the sawing efficiency of the intelligent sawing system was 18.1 (48%) higher than that of the original sawing system when sawing a grooved section sawing material, which verifies the good control effect of the proposed scheme.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.1
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• pp.29-37
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• 1999

In general, the information processing capability of a neural network is determined by its architecture and efficient training patterns. However, there is no systematic method for designing neural network and selecting effective training patterns. Evolutionary Algorithms(EAs) are referred to as the methods of population-based optimization. Therefore, EAs are considered as very efficient methods of optimal system design because they can provide much opportunity for obtaining the global optimal solution. In this paper, we propose a new method for finding the optimal structure of neural networks based on competitive co-evolution, which has two different populations. Each population is called the primary population and the secondary population respectively. The former is composed of the architecture of neural network and the latter is composed of training patterns. These two populations co-evolve competitively each other, that is, the training patterns will evolve to become more difficult for learning of neural networks and the architecture of neural networks will evolve to learn this patterns. This method prevents the system from the limitation of the performance by random design of neural networks and inadequate selection of training patterns. In co-evolutionary method, it is difficult to monitor the progress of co-evolution because the fitness of individuals varies dynamically. So, we also introduce the measurement method. The validity and effectiveness of the proposed method are inspected by applying it to the visual servoing of robot manipulators.

• Journal of Positioning, Navigation, and Timing
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• v.1 no.1
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• pp.35-43
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• 2012

The UGV is one of the special field robot developed for mine detection, surveillance and transportation. To achieve successfully the missions of the UGV, the accurate and reliable navigation data should be provided. This paper presents design and implementation of multi-sensor-based open architecture integrated navigation for localization of UGV. The presented architecture hierarchically classifies the integrated system into four layers and data communications between layers are based on the distributed object oriented middleware. The navigation manager determines the navigation mode with the QoS information of each navigation sensor and the integrated filter performs the navigation mode-based data fusion in the filtering process. Also, all navigation variables including the filter parameters and QoS of navigation data can be modified in GUI and consequently, the user can operate the integrated navigation system more usefully. The conventional GPS/INS integrated system does not guarantee the long-term reliability of localization when GPS solution is not available by signal blockage and intentional jamming in outdoor environment. The presented integration algorithm, however, based on the adaptive federated filter structure with FDI algorithm can integrate effectively the output of multi-sensor such as 3D LADAR, vision, odometer, magnetic compass and zero velocity to enhance the accuracy of localization result in the case that GPS is unavailable. The field test was carried out with the UGV and the test results show that the presented integrated navigation system can provide more robust and accurate localization performance than the conventional GPS/INS integrated system in outdoor environments.

• Journal of Biomedical Engineering Research
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• v.31 no.3
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• pp.227-233
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• 2010

This study analyzed performance according to kick point and stiffness of Soft-$golf^{TM}$ shaft. This research team developed soft-$golf^{TM}$ as a new fusion sports with similar motions with golf and it can be learned safely for all age groups in 2002. The head of Soft-$golf^{TM}$ club is made of zinc alloy and has a mesh or a grid structure, and shaft uses carbon graphite to reduce the total weight of the club. To improve carry distance and to assure consistency of a ball during Soft-$golf^{TM}$ swing, this study manufactured shaft with various kick points (low, middle and high) and stiffness (stiff, regular, lady, morelady) and analyzed a swing motion with characteristics of each shaft presented in a dynamic condition such as a ball's speed, a head's torsion angle and a ball's deviation with ProAnalyst program through a high-speed camera taking pictures using a swing machine robot system(Robo-7). From all of the results, this study determined an appropriate shaft of Soft-$golf^{TM}$.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.6
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• pp.815-820
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• 2013

With the development of technology, there has been a considerable increase in the number of skyscrapers in the world. Accordingly, there are increasing requirements with regard to maintenance, such as cleaning, painting, and inspection. However, it is extremely dangerous to work on the walls of buildings, and falls from buildings have accounted for a large proportion of construction accidents. In particular, as the number of buildings with irregular shapes increases, the accident rate during maintenance work has increased each year, with most accidents leading to deaths. An alternative solution must be developed with the commercialization of automatic systems. In this study, fundamental research has been conducted for drafting and commercializing an automation tool with a built-in guide system that can perform cleaning.

• International journal of advanced smart convergence
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• v.7 no.1
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• pp.42-47
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• 2018

Recently, as the demand for limited resources continues to rise and problems of resource depletion rise worldwide, the importance of renewable energy is gradually increasing. In order to solve these problems, various methods such as energy conservation and alternative energy development have been suggested, and biogas, which can utilize the gas produced from biomass as fuel, is also receiving attention as the next generation of innovative renewable energy. New and renewable energy using biogas is an energy production method that is expected to be possible in large scale because it can supply energy with high efficiency in compliance with energy supply method of recycling conventional resources. In order to more efficiently produce and manage these biogas, a biogas plant has emerged. In recent years, a large number of biogas plants have been installed and operated in various locations. Organic wastes corresponding to biogas production resources in a biogas plant exist in a wide variety of types, and each of the incoming raw materials is processed in different processes. Because such a process is required, the case where the biogas plant process is inefficiently operated is continuously occurring, and the economic cost consumed for the operation of the biogas production relative to the generated biogas production is further increased. In order to solve such problems, various attempts such as process analysis and feedback based on the feedstock have been continued but it is a passive method and very limited to operate a medium/large scale biogas plant. In this paper, we propose "CNN-based production yield prediction algorithm for increasing process efficiency of biogas plant" for efficient operation of biogas plant process. Based on CNN-based production yield forecasting, which is one of the deep-leaning technologies, it enables mechanical analysis of the process operation process and provides a solution for optimal process operation due to process-related accumulated data analyzed by the automated process.

• International Journal of Precision Engineering and Manufacturing
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• v.8 no.2
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• pp.44-48
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• 2007

In recent years, the size of plane substrates and semiconductor wafers has increased. As conventional contact transportation systems composed of, for example, carrier rollers, belt conveyers, and robot hands carry these longer and wider substrates, the increased weight results in increased potential for fracture. A noncontact transportation system is required to solve this problem. We propose a new noncontact transportation system combining acoustic viscous and aerostatic forces to provide damage-free transport. In this system, substrates are supported by aerostatic force and transported by acoustic viscous streaming induced by traveling wave deformation of a disk-type stator. A ring-type piezoelectric transducer bonded on the stator excites vibration. A stator with a high Q piezoelectric transducer can generate traveling vibrations with amplitude of $3.2{\mu}m$. Prior to constructing a carrying road for substrates, we clarified the basic properties of this technique and stator vibration characteristics experimentally. We constructed the experimental equipment using a rotational disk with a 95-mm diameter. Electric power was 70 W at an input voltage of 200 Vpp. A rotational torque of $8.5\times10^{-5}Nm$ was obtained when clearance between the stator and disk was $120{\mu}m$. Finally, we constructed a noncontact transport apparatus for polycrystalline silicon wafers $(150(W)\times150(L)\times0.3(t))$, producing a carrying speed of 59.2 mm/s at a clearance of 0.3 mm between the stator and wafer. The carrying force when four stators acted on the wafer was $2\times10^{-3}N$. Thus, the new noncontact transportation system was demonstrated to be effective.

• Design & Manufacturing
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• v.15 no.1
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• pp.57-65
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• 2021

Pump cap is a product that is widely used due to its ease of use and simple operation. These pump caps are applied to heterogeneous functional cosmetics and are being developed as dual pump caps. However, the conventional dual pump cap has a problem in that it is inconvenient to use and leakage occurs. In addition, it is formed of a plurality of materials, and there is a problem that is difficult to recycle. Lately, since the problem of environmental pollution is getting serious, the dual pump cap, which is difficult to recycle, cannot be used. Currently, eco-friendliness has been considered in Korea, and there are no dual pump cap containers with excellent sealing performance. Therefore, in this study, a dual pump cap container made of eco-friendly material was designed. In addition, finite element analysis was performed to verify the design feasibility of the product.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1500-1503
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• 2003

One of the main goals in the rehabilitation of SCI patients is to enable the patient to stand and walk themselves. We are developing high-thrust powered gait orthosis(PGO) that use air muscle actuator(shadow robot Co., UK) to be assisted gait and rehabilitation purposes of them. We made of PD controller and measured hip joint angle by its load and the pressure to control air muscle of PGO. As a results, maximum flexion angle of hip joint is $20^{\circ}$, and angular velocity is 30.4${\pm}2.5^{\circ}/sec$, and then delay time of system was average 0.62${\pm}$0.03s. As the hip flexion angle and the pelvic angle is decreased during the gait with PGO, the patient can walk faster. By using the PGO, the energy consumption can also be decreased. therefore, the proposed PGO can be a very useful assitive device for the paraplegics to walk.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.15 no.1
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• pp.53-59
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• 2015

This paper proposes a novel method for acoustically and wirelessly transmitting data underwater with a high transmission rate. The method uses the most promising physical layer and multiple access technique (i.e., the code division multiple channel access technique) to divide the channel into subchannels. Data is transmitted through these subchannels. The codes are pseudo-random noise (PN) sequences. In the spread-spectrum technique, a signal such as electrical, electromagnetic, acoustic signal generated in a particular bandwidth is deliberately spread in the frequency domain, which results in a signal with a wider bandwidth. This paper reviews the possibility of application of the direct-sequence code division multiple access (DS-CDMA) technique in an underwater system using MATLAB. As the result of our review, we recognize that the DS-CDMA technique can be applied to underwater environments.