• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1983-1989
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• 2005

Industrial robots are powerful, extremely accurate multi-jointed systems, but they are heavy and highly rigid because of their mechanical structure and motorization. Therefore, sharing the robot working space with its environment is problematic. A novel pneumatic artificial muscle actuator (PAM actuator) has been regarded during the recent decades as an interesting alternative to hydraulic and electric actuators. Its main advantages are high strength and high power/weight ratio, low cost, compactness, ease of maintenance, cleanliness, readily available and cheap power source, inherent safety and mobility assistance to humans performing tasks. The PAM is undoubtedly the most promising artificial muscle for the actuation of new types of industrial robots such as Rubber Actuator and PAM manipulators. However, some limitations still exist, such as the air compressibility and the lack of damping ability of the actuator bring the dynamic delay of the pressure response and cause the oscillatory motion. In addition, the nonlinearities in the PAM manipulator still limit the controllability. Therefore, it is not easy to realize motion with high accuracy and high speed and with respect to various external inertia loads in order to realize a human-friendly therapy robot To overcome these problems a novel controller, which harmonizes a phase plane switching control method with conventional PID controller and the adaptabilities of neural network, is newly proposed. In order to realize satisfactory control performance a variable damper - Magneto-Rheological Brake (MRB) is equipped to the joint of the manipulator. Superb mixture of conventional PID controller and a phase plane switching control using neural network brings us a novel controller. This proposed controller is appropriate for a kind of plants with nonlinearity uncertainties and disturbances. The experiments were carried out in practical PAM manipulator and the effectiveness of the proposed control algorithm was demonstrated through experiments, which had proved that the stability of the manipulator can be improved greatly in a high gain control by using MRB with phase plane switching control using neural network and without regard for the changes of external inertia loads.

• 대한공업교육학회지
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• v.33 no.2
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• pp.218-231
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• 2008

The purpose of this study was made for the pre-teacher of university to enhance understanding for the concept of engine performance and to provide information regarding engine performance in the institute of teacher educator. This study was carried out through engine performance experiment with The Cussons Engine Test Bed P8250, internal combustion engine, in order to analyze data quantitatively, and apply and verify factors of controlling engine performance. The main results of this study are as follows: First, power and brake horsepower increased linearly, and torque over the mid-speed as engine rps(revolution per second) decreased. Second, the change of torque and specific fuel consumption were able to be verified and the concept of engine performance was able to be understood. Third, the experimental values of brake horsepower and torque on engine performance showed the same tendency as theoretical values. Fourth, air/fuel ratio increased proportionally as engine speed increased.

• Particle and aerosol research
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• v.19 no.2
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• pp.31-42
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• 2023

The charge and magnetic characteristics of LM (Low-metallic) and NAO (Non-asbestos-organic) brake wear particles were analyzed. The ratio of charged particles from total particles is about 86% of the LM pad and about 92% of the NAO pad. Number of charge per particle from the NAO pad is also higher than that of the LM pad. The ratio of magnetic particles from total particles increases with the particle size. The ratio of magnetic particles from the LM pad is about 15% for the particles with the size of 1 ㎛, and about 74% for ones with 5 ㎛. The ratio from the NAO pad is about 5% for the particles with the size from 0.5 ㎛ to 2 ㎛, and about 80% for the particles with 5 ㎛. Through the analysis of the components of the two pads with SEM-EDS (Scanning Electron Microscopy - Energy Dispersive X-ray Spectroscopy), it was found that the LM pad was occupied with more iron fraction than the NAO pad and that PM_2.5-10 was occupied with more iron fraction than PM_2.5. The particles smaller than 10 ㎛ (i.e. PM₁₀) from the LM pad contained about 83% of charged particles, about 43% of magnetic particles, and about 93% of charged or magnetic particles. PM₁₀ from the NAO pad contained about 88% of charged particles, about 15% of magnetic particles, and about 89% of charged or magnetic particles.

• KIPE Magazine
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• v.9 no.4
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• pp.37-41
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• 2004

1996년 출시이래, MiniSKiiP은 가격 효과적이고 신뢰성 높은 CIB모듈(Converter-Inverter-Brake chopper)로 인정을 받아왔다. 수백만 개가 팔림에 따라, CIB급 모듈 중에서 시장에서의 리더로서의 자리를 굳혀 왔다. 현재 MiniSKiiP은 대량 생산이 필요한 소형 인버터 제품에 광범위하게 사용되고 있다.(중략)

• Journal of Drive and Control
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• v.8 no.1
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• pp.60-65
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• 2011

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.6
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• pp.684-693
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• 2016

The luxury car industry has grown 10.5 % every year from 2010 to 2014. For this reason, it is very important for automotive companies to improve profitability and brand value. High-performance brake systems have become an absolute necessity because of the increase in engine power and customer preference among other factors. Also, competing automotive companies actively reinforce domestic production in order to maintain quality and infrastructure for luxury cars. In this regard, we demonstrated new carbon ceramic brakes to improve brake reliability for luxury cars and to improve the competitiveness of automotive companies. Finally, we propose the next-generation braking technology by predicting technological evolution trends.

• Tribology and Lubricants
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• v.30 no.6
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• pp.330-336
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• 2014

Sintered metallic brake pads and low alloy heat resistance steel disks are applied to mechanical brake systems in high energy moving machines that are associated with recently developed 200km/h trains. This has led to the speed-up of conventional urban rapid transit. In this study, we use a lab-scale dynamometer to investigate the effects of the composition of friction materials on the tribological characteristics of sintered metallic brake pads and low alloy heat resistance steel under dry sliding conditions. We conduct test under a continuous pressure of 5.5 MPa at various speeds. To determine the optimal composition of friction materials for 200 km/h train, we test and the evaluate frictional characteristics such as friction coefficients, friction stability, wear rate, and the temperature of friction material, which depend on the relative composition of the Cu-Sn and Fe components. The results clearly demonstrate that the average friction coefficient is lower for all speed conditions, when a large quantity of iron power is added. The specimen of 25 wt% iron powder that was added decreased the wear of the friction materials and the roughness of the disc surface. However when 35 wt% iron powder was added, the disc roughness and the wear rate of friction materials increased By increasing the amount of iron powder, the surface roughness, and temperature of the friction materials increased, so the average friction coefficients decreased. An oxidation layer of $Fe_2O_3$ was formed on both friction surfaces.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.191-192
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• 2016

본 논문은 전기식 회생 보조 브레이크의 넓은 범위의 입력전압을 가진 전기에너지를 받아서 넓은 범위의 출력전압을 가진 리튬이온 배터리에 충전할 수 있도록 Buck-boost 토폴로지를 제안하고, 배터리와의 절연을 위해 출력 효율이 좋은 LLC 토폴로지를 제안한다. 제안된 2단 구성 회로의 유효성은 실험을 통해 검증되었다.

• Journal of Mechanical Science and Technology
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• v.15 no.10
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• pp.1442-1450
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• 2001

The EGR system has been widely used to reduce nitrogen oxides (NO$\_$x/) emission, to improve fuel economy and suppress knock by using the characteristics of charge dilution. However, as the EGR rate at a given engine operating condition increases, the combustion instability increases. The combustion instability increases cyclic variations resulting in the deterioration of engine performance and emissions. Therefore, the optimum EGR rate should be carefully determined in order to obtain the better engine performance and emissions. An experimental study has been performed to investigate the effects of EGR on combustion stability, engine performance,70x and the other exhaust emissions from 1.5 liter gasoline engine. Operating conditions are selected from the test result of the high speed and high acceleration region of SFTP mode which generates more NO$\_$x/ and needs higher engine speed compared to FTP-75 (Federal Test Procedure) mode. Engine power, fuel consumption and exhaust emissions are measured with various EGR rate. Combustion stability is analyzed by examining the variation of indicated mean effective pressure (COV$\_$imep/) and the timings of maximum pressure (P$\_$max/) location using pressure sensor. Engine performance is analyzed by investigating engine power and maximum cylinder pressure and brake specific fuel consumption (BSFC)

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.4
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• pp.145-151
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• 2005

Natural gas is one of clean fuels that can replace petroleum-based fuels, because it has low exhaust emission, comparatively high thermal efficiency and abundant deposits. In this addition, owing to high octane number and wide lean flammability limit, it has a strong point to increase the compression ratio. For this reason, the research is being actively executed to increase the generating power and thermal efficiency of the engine by raising the compression ratio through utilization of high octane number relevant to development of CNG engine. In this study, 0.63L single cylinder diesel engine has been used to alter easily compression ratio. Compression ratio has gotten under control by modifying the thickness of gasket between cylinder head and block without major structural modifications. As the result, as compression ratio has increased, generating power and fuel consumption ratio have been improved. As for emission concentration, as compression ratio has increased, THC concentration has been decreased while exhause concentration of NOx increased. In case compression ratio has excessively increased, brake output decrease and cycle variation have been increased. As the result acquired by analyzing brake output, fuel consumption ratio, cycle variation and exhaust, the engine driving condition has acquired $\varepsilon=13$ as the optimal compression ratio in this study.