• Journal of the Institute of Convergence Signal Processing
• /
• v.11 no.1
• /
• pp.63-73
• /
• 2010

This paper presents the optimal design method of an overlapped ultrasonic sensor ring for reduced positional uncertainty, and its application to the obstacle detection with improved resolution. Basically, it is assumed that a set of ultrasonic sensors are installed to form a circle at regular intervals with their beams overlapped. First, exploiting the overlapped beam pattern, the positional uncertainty inherent to an ultrasonic sensor is shown to be significantly reduced. Second, for an ideal ultrasonic sensor ring of zero radius, the effective beam width is defined to represent the positional uncertainty, and the optimal number of ultrasonic sensors required for minimal effective beam width is obtained. Third, for an actual ultrasonic sensor ring of nonzero radius, the design index is defined to represent the degree of positional uncertainty, and an optimal design of an overlapped ultrasonic sensor ring consisting of commercial ultrasonic sensors with low directivity is given. Fourth, given measured distances from ultrasonic sensors, the geometric method is described to compute the obstacle position with reference to the center of a mobile robot. Finally, through experiments using our overlapped ultrasonic sensor ring prototype, the validity and performance of the proposed method is demonstrated.

• Journal of Korea Society of Industrial Information Systems
• /
• v.19 no.6
• /
• pp.25-31
• /
• 2014

Gas metal arc welding (GMAW) is currently the most widely used arc welding processes in the industry because of its high metal deposition rate, flexibility and low cost. It is attractive for high-productivity manufacturing applications and is well suited to automatic or robotic welding. Welding voltage and current have a significant impact on the weld bead. However, welding voltage and current are changed variously according to welding condition and user environment, and prediction is impossible. To determine the welding conditions, the welding current and voltage are applied to the appropriate data analysis techniques. In this paper, we used the moving average filter to the welding voltage and current data, and normal and abnormal welding waves were distinguished.

• Journal of Biomedical Engineering Research
• /
• v.18 no.4
• /
• pp.447-456
• /
• 1997

When the disabled is operating a rehabilitation assisting system with a joystick by himself, unlike in the case of a normal person, tremor with joystick control or instant miscontrol can often occur. If these misoperations should be directly relayed to the system, shaking or malfunction of the mobile rehabilitation assisting system might be the result. The safety of the disabled is of prime concern. To solve this problem, that is, to prevent the miscontrol of the disabled operator and avoid crashes into his or her surroundings, we propose the force-reflection locomotion algorithm with the joystick. This method uses ultrasonic sensors to measure the distance between the object and mobile robot. Based on the reception of sensory data, the necessary torque is applied via the joystick to the attatched motor. To confirm the effectiveness of the proposed method, the subjects on the reflected force by the dynamic characteristics of the joystick and the reflected force by the distance information are tested Even though there are some differences in human dexterity, we confirmed the fact that the information from the obstacles was relayed to the operator via the joystick and resulted in an improved operational performance and safety level with regard to those obstacles.

• Proceedings of the Korea Technology Innovation Society Conference
• /
• 2005.10a
• /
• pp.619-636
• /
• 2005

기술의 복합성이 증가하고 제품의 존속 수명주기가 불확실해지면서 기술개발자가 의도하는 바와는 관계없이 사업 영역과 기술기반의 변하고 있다. 이러한 환경 속에서 산업 내 기술의 특성을 분석하는 이른바 산업기술분석 역할은 매우 중요하다. 그러나 그 범위가 매우 광범위하고 그 중 기술개발에 있어 관련된 산업기술분석의 프레임이 구체적으로 적용된 사례를 제한적이다. 따라서 다양한 산업을 지원하는 정부 기술개발 기회의 경우, 반도체에 적용되는 모듈러 기반 기술개발 틀과 성과분석이 항공기, 지능형 로봇과 같은 복합 시스템 산업에 그대로 적용해왔던 것이 현실이다. 이는 기술을 제품화함에 있어 필수적인 개발시스템의 기술적 속성이 산업기술 분석 방법론에 효과적으로 체화되지 못했기 때문이다 본 연구는 시스템과 서브 부품으로 구성되는 제품설계 특성을 구조화한 제품 아키텍쳐 이론을 소개하고 이를 기술개발체계에 적용하는 실증적 연구를 수행한다. 실증적 분석을 위해 항공기 개발 전 과정을 분해하고 아키텍쳐 분석방법을 실제 적용하였다. 아키텍쳐는 대표적으로 모듈 형(Module)과 인테그랄 형(Integral)으로 구분한다. 실제로 한 가지의 제품 안에도 모듈형 부품과 인테그랄 형 부품이 복합적으로 혼합되어 있는 경우가 많다. 또한, 제품을 어느 레벨까지 분해할 지에 따라 모듈화의 정도도 달라 질 수 있다. 본 연구는 아키텍쳐 중 Integral 속성의 정도를 파악하여 아키텍쳐 정도를 파악하였다. 측정 기준으로 첫째, 타 부품과의 기능적인 상호연관성과 둘째, 체계종합 설계와의 상호의존성 두 가지를 설정하였다. 이러한 두 가지 아키텍쳐 기준을 547개의 항공우주 부품 및 기술을 적용해 본 결과, 항공기 개발과정은 총 $65\%$의 인테그럴 속성을 가지고 있으며 기술분야 별로 아키텍쳐 정도가 다르게 나타나고 있었다(전자 부품은 분야는 오히려 모듈형에 가까웠음). 비단 항공기 개발과정 뿐만 아니라 다른 산업, 제품에도 적용될 수 있는 틀을 마련함으로써, 기존 연구개발기회에서 산업기술 분석을 통한 체계적 기획으로 전환할 수 있는 새로운 대안을 제시한다. 결과적으로 산업기술의 특성과 구조를 반영한 기술개발 방법론으로 아키텍쳐 이론을 적용할 수 있는 단초를 마련했으며, 이것은 본 논문이 기대하는 바이기도 하다.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.13 no.5
• /
• pp.949-958
• /
• 2018

A voice recognition control system is a system for controlling a peripheral device by recognizing a voice. Recently, a voice recognition control system have been applied not only to smart devices but also to various environments ranging from IoT(: Internet of Things), robots, and vehicles. In such a voice recognition control system, the recognition rate is lowered due to the ambient noise in addition to the voice of the user. In this paper, we propose a dual channel acoustic beamforming hardware architecture for MEMS(: Microelectromechanical Systems) microphones to eliminate ambient noise in addition to user's voice. And the proposed hardware architecture is designed as ASIC(: Application-Specific Integrated Circuit) using TowerJazz $0.18{\mu}m$ CMOS(: Complementary Metal-Oxide Semiconductor) technology. The designed dual channel acoustic beamforming ASIC has a die size of $48mm^2$, and the directivity index of the user's voice were measured to be 4.233㏈.

• Journal of Digital Convergence
• /
• v.17 no.2
• /
• pp.155-161
• /
• 2019

Electroencephalography (EEG), a representative method of identifying temporal and spatial changes in brain activity, is a voluntary electrical activity measurable in the human scalp. Various interface technologies have been provided to control EEG activity, and it is possible to operate a machine such as a wheelchair or a robot through brainwaves. The characteristics of EEG data are collected in various types of channels in real time, and a server system for analyzing them is required to have an independent and lightweight system for the platform. In these days, the Spring platform is used as a large business server as an independent, lightweight server system. In this paper, we propose an EEG analysis system using the Spring server system. Using the proposed system, the reliability of EEG control can be enhanced, and analysis and control interface expansion can be provided in various aspects such as game and medical areas.

• International journal of thyroidology
• /
• v.11 no.2
• /
• pp.109-116
• /
• 2018

It is very important to identify recurrent laryngeal nerve (RLN) and prevent RLN injury during thyroid surgery. The intraoperative neuromonitoring (IONM) for the prevention of RLN injury is a useful method because it can identify the location and status of RLN and predict postoperative vocal cord function easily. The IONM consists of a stimulating side that applies electrical stimulation to the nerve and a recording side that measures the surface electromyography (EMG) of the vocal cord muscle through electrode endotracheal tube. The nerve stimulator and surgical dissector are separate instruments. So, during IONM for the prevention of the RLN injury in conventional, endoscopic, or robotic thyroid surgery, repeated exchanging between surgical instruments and the nerve stimulator is inconvenient and time consuming. On the recording side, the accuracy of the electrode endotracheal tube which measures the EMG of the vocalis muscle can be affected by contact with between electrode and vocal fold and position change of patient. We would like to introduce recent several researches to overcome the current limitations of IONM.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.23 no.9
• /
• pp.1032-1037
• /
• 2019

In the existing pharmacy automation system, quantity control was carried out only in the memory without first measuring the quantity of the medicine and during the operation of the facility. As a result, the number of drugs that have already been deducted during operation at the time of a facility error has not been managed. Serious problems are caused by important medicines that need to be managed because of lack of quantity control. In addition, the user had to refill the drug when it was exhausted because the user could not know the amount of the drug outside the facility. When the drug was out of stock, the facility was operating with loss of time to restart and the time to replenish the drug. Thus, in this paper, we designed and applied system to control the quantity of medicines frequently by adding displacement sensors to the robot of the facility.

• Journal of Platform Technology
• /
• v.8 no.1
• /
• pp.24-32
• /
• 2020

This paper designed and manufactured a chip mounter based on 3D printer technology that can be used for educational research or sample production to disseminate chip mounter, a core technology of SMT line. A stepper motor with open loop control is used for low cost drive design. The shortcomings of the motor's vibration and disassembly caused by the use of the step motor were compensated by the Micro-Step control method. In the chip mounter experiment, the gerber file was generated on the small chip mounter, printed at the actual size, and the solder cream was printed on the HASL-treated PCB in the same manner as the sample board fabrication. As a result of the experiment, unlike the 2012 micro components, parts such as SOIC and TQFP that require correction are twice as long as the component mounting time, but it can be confirmed that they are mounted relatively accurately. In addition, as a result of repeatedly measuring the error of the initial position 10 times, it was confirmed that a relatively small error of about 0.110mm occurs.

• The Journal of the Korea Contents Association
• /
• v.22 no.7
• /
• pp.670-675
• /
• 2022

In the era of the 4th industrial revolution, everything is data-centric. The type and amount of data may be central, and new data may be required in special circumstances. As 3D printers are used in various fields, there are fields that are newly challenged. In particular, in the medical field, new attempts that have not been considered before are taking place. This paper is a study to enable research in fields that require physical properties of the human body. In the meantime, research using human organs has mainly used the materials made of silicon. We measure the physical properties of the human body from cadavers, apply these characteristics to develop new materials, and develop artificial organs with 3D printers. Using the artificial organs made in this way, you can practice surgery with a robot that removes kidney stones. In this paper, we would like to introduce a series of research processes to develop advanced materials similar to human organs.