압전 밸브용 압력 레귤레이터

윤소남,김찬용,서우석,박중호,함영복 사단법인 유공압건설기계학회 2006 드라이브·컨트롤 Vol.3 No.2

The pressure regulator which is used for controlling the reducing pressure in the piezoelectrically driven pneumatic valve has been studied. The pneumatic valve of this study object is 2-stage type and consists of a piezoelectric actuator, a controller, a poppet valve and a pressure regulator. Nominal flow of 50 1pm, maximum operating pressure of 0.9MPa and frequency characteristic of 10Hz and over are required in this pneumatic valve, but the pressure regulator is needed because piezoelectric actuator has no ability to control the pressure of 0.9MPa directly. In this study, bimorph type PZT actuator of 25.2 mm(L)x7.2 mm(W)x0.5 mm(H) with constant of -220x10-12 CN-1 was proposed and investigated. Maximum operating force of 0.052 N and maximum displacement of 63 ㎛ were gotten from the fabricated PZT actuator. From the analysis results, the orifice diameter or 0.6mm for a piezoelectric actuator was derived and then the pressure regulator which can be operated under 0.15 MPa easily was designed and manufactured. Performance and effects of design parameters were simulated by the Simulink of Matlab software, and it was confirmed that the performance characteristics of manufactured pressure regulator are superior in the common use pressure of 0.5 MPa to 0.7MPa, The results show that the proposed pressure regulator is suitable for the pneumatic valve with a PZT actuator.

실시간 골재의 입도분포 측정을 위한 비전시스템 개발

서명국,이호연 사단법인 유공압건설기계학회 2024 드라이브·컨트롤 Vol.21 No.4

The vision-based aggregate analysis system is a device that captures images of aggregates transferred to a conveyor belt and analyzes these images to measure the particle size distribution of the aggregates. While this system offers many technological advantages, it also has limitations since the size of aggregates is determined solely from images. In particular, the need to convert the size indicated in the image to actual size and the inability to recognize aggregates within the aggregate pile negatively impact measurement accuracy.

실작업시 주행속도에 따른 자주식 마늘 수집기 소요 동력 분석

김완수,도영우,문석표,남영조,권승귀 사단법인 유공압건설기계학회 2024 드라이브·컨트롤 Vol.21 No.4

This study aims to measure and analyze the power requirements of a self-propelled garlic collector under various travel speed conditions. The research utilized a 40.2 kW-class garlic collector, which consists of three main components: a collecting part, a conveying part, and a crawler-type driving part. Field experiments were conducted to gather load data for each component at three different travel speeds, specifically focusing on the power required by the driving, collecting, and conveying parts. The findings revealed total power requirements of 6.87 kW, 8.88 kW, and 12.33 kW at travel speeds of 0-0.15 m/s, 0.15-0.30 m/s, and 0.30-0.45 m/s, respectively. The power requirement increased by 29.3% when the travel speed increased from 0-0.15 m/s to 0.15-0.30 m/s, and by an additional 38.8% at the highest speed. These results indicate a significant rise in overall power requirements as travel speed increases. The data provide essential insights into the load requirements for each main component at different speeds, serving as foundational information for the optimal design and development of simulation models for garlic collector in the future.

비전센서를 활용한 양날 도로절단기의 절단경로 인식 기술 개발

서명국,권진욱,정황훈,주정함,김영진 사단법인 유공압건설기계학회 2023 드라이브·컨트롤 Vol.20 No.1

With the recent trend of intelligence and automation of construction work, a double-blade road cutter is being developed that automatically enables cutting along the cutting line marked on the road using a vision system. The road cutter can recognize the cutting line through the camera and correct the driving route in real-time, and it detects the load of the cutting blade in real-time to control the driving speed in case of overload to protect workers and cutting blades. In this study, a vision system mounted on a double-blade road cutter was developed. A cutting route recognition technology was developed to stably recognize cutting lines displayed on non-uniform road surfaces, and performance was verified in similar environments. In addition, a vision sensor protection module was developed to prevent foreign substances (dust, water, etc.) generated during cutting from being attached to the camera.

밭농업용 다목적 플랫폼의 견인동력 및 구동토크 예측을 위한 시뮬레이션 모델 개발 및 검증

전현호,백승민,백승윤,홍이수,김택진,최용,김영근,이상희,김용주 사단법인 유공압건설기계학회 2023 드라이브·컨트롤 Vol.20 No.1

Although the upland field area of Korea is high as 44.8%, the platform optimized for the upland field is insufficient. It is necessary to develop an optimized platform for the upland field because the upland field environment is an irregular environment with many slopes. In addition, due to the characteristic of agricultural operations, the traction power and torque of the platform have to be sufficient. Therefore, in this study, a simulation model that can predict the traction power and driving torque of a crawler-type platform for the upland field was developed and validated using the specifications of the crawler platform. The simulation model was developed using Amesim (19.1, Siemens, Germany). The development of the model was conducted using the specifications of the platform. A measurement system was developed to validate the simulation model. The traction power data of the simulation model was validated with the traction force and vehicle speed. The driving torque data of the simulation model was validated with the torque of the sprocket on the crawler system. As a result of the analysis, the error between measurement and simulation results occurred within 10%, and it was determined that the traction power and driving torque prediction of the crawler platform using this model was possible.

사물인터넷 센서를 이용한 동적 부품의 스트레인 측정 방법

김바다,안영철,박정현,유영준,이철희,이대엽 사단법인 유공압건설기계학회 2023 드라이브·컨트롤 Vol.20 No.1

The aim of this study was to develop a method for installing strain gauges on moving, lubricating oil-filled, and sealed parts, such as drive shafts of equipment, including construction machinery. A measuring device was constructed using an embedded CPU and an IoT sensor to measure the strain of the strain gauge, which allowed for the measurement of axial torque and axial force, and subsequent analysis. To verify the performance of the developed device, the axial torque and axial force of the forklift were measured during operation using a strain gauge attached to the inside of the drive shaft. This study confirmed the possibility of measuring and analyzing the strain of a moving part, such as the inside of a drive shaft, which is sealed and filled with hydraulic oil.

항공기 구조용 소방차 탱크룸의 구조 안정성 평가 및 설계 개선에 대한 해석적 연구

권혁진,강명철,임수일,김한욱,홍정기,이호,황영선 사단법인 유공압건설기계학회 2023 드라이브·컨트롤 Vol.20 No.1

In this study, the structural stability of the tank room of an aircraft rescue fire engine is to be studied. The tank room of the aircraft rescue fire engine is filled with fire extinguishing water and chemicals. Fire extinguishing water and chemical are filled to a capacity of about 12.5 tons and are subjected to high stress. The tank room is made of PP material with low yield stress. Structural analysis of the tank room is performed and structural weakness is analyzed. In addition, if a structural problem occurs as a result of structural analysis, an analysis simulation result is presented to derive an improved design and to show the validity of the structural stability of the tank room.

농업용트랙터 ROPS 시험의 신뢰성 향상을 위한 측정불확도 추정

임류갑,강영선,김택진 사단법인 유공압건설기계학회 2023 드라이브·컨트롤 Vol.20 No.1

The agricultural tractor ROPS test method according to OECD code 4 is a test to assess whether the driver's safety area can be secured when a tractor overturns, and reliability should be ensured. In this study, a model formula and procedure for calculating measurement uncertainty expressing reliability in the field of agricultural machinery testing were established according to the ISO/IEC Guide 98-3:2008. The characteristics of the ROPS test device were assessed and repeated tests were performed, and the were used as factors to calculate the measurement uncertainty. As a result of repeated tests, the accuracy was higher than 1.9 % in all load directions; thus, they were, applied to calculate the type A standard uncertainty. The final expanded uncertainty was calculated within the range of less than ± 7.76 kN of force and ± 6.96 mm of deformation in all load directions.

치과용 유니트체어 유압구동 시스템 해석모델 개발

노대경,이동원,김택준,장주섭 사단법인 유공압건설기계학회 2023 드라이브·컨트롤 Vol.20 No.1

From the perspective of dental chair manufacturers, it is important to of localizing hydraulic system in order to secure market competitiveness. This study aims to develop the analysis model of a dental chair which overseas companies secure core technologies. The study follows the steps below. First, the component parts of the solenoid valve unit of a foreign leading company are analyzed and implemented in virtual environment. Second, dynamic behavior scenario is established based on solenoid valve signal chart provided by a foreign leading company. The analysis model is verified and its performance is analyzed using dynamic behavior according to each scenario. Third, a simulation is carried out to determine whether the cylinder velocity of designed hydraulic system surpasses 1cm/s as required by the design.

공기압축기 소비에너지 평가에 관한 연구

장지성 사단법인 유공압건설기계학회 2020 드라이브·컨트롤 Vol.17 No.2

Various efforts have been initiated to reduce the energy consumption of the compressor as it is one of the approaches to saving a large portion of the fixed cost of the production site. Various results of reducing the energy consumption of the compressor have been reported, but to reduce the energy consumption of the compressors fundamentally, regular management of the compressor should ensure optimum operation. This requires periodic on-site visits by experts, but is often overlooked as a cost issue, resulting in the use of the compressor in low-efficiency conditions. Thus, it is necessary to develop a low-cost evaluation technology for compressor condition monitoring and efficiency analysis to ensure that the compressor is always driven at the optimum efficiency without imposing undue burden on the compressor user. In this study, a sensor was installed at the inlet, outlet, and power supply of the compressor, and a method for evaluating the energy consumption of the compressor using the minimum sensor was derived. The experimental results are presented to show the validity of the proposed method. It was confirmed that the energy consumption of the compressor can be easily as well as efficiently evaluated by using the method developed in this study.