In this paper, the control technique of the stepping motor using back electromotive force(B-EMF) without encoder is investigated. The stepping motor generally uses the rotary encoder to detect the rotor position. Since this method increases the cost and the motor configuration size, the new closed-loop control method applied for the B-EMF was implemented by using current detect circuit, AD-converter, and micro controller unit(MCU). The contorl loop of stepping motor became very simplified. The current change of stepping motor measured by the amplifier was measured and analyzed, when the missing step is occurred. Based on the data from current feedback, position errors were compensated and confirmed by using AD-converter.

This study documents the 3-phase BLDC(Brushless DC) motor to improve conventional ventilator motor. Energy efficiency, noise, and air pollution reduction for the high-performance vibration of the BLDC motor has been used in many fields. BLDC motors for ventilator, we studied the controller and software.

In this paper investigated the without encoder drive for stepping motor using back electromotive force(B-EMF). In generally stepping motor should be rotary encoder to rotor position, the rotary encoder is adopted to detect the position. But in this way increase cost and volume. This paper propose B-EMF & closed-loop method was implemented using current detect circuit, AD-converter and MCU(micro controller unit). So that stepping motor environment is very simplify. The current of stepping motor was measured by using amplifier. The change of current was measured and analyzed, when the missing step occurred. Based on data from current feedback, position errors were compensated and it was confirmed by using AD-converter.

Based on the attitude of science discovery, an industrial induction motor silencer is designed and developed, and the performance of this silencer is evaluated experimentally in this paper. The basic principle of the silencer was used as the parabola principle. During the experiment, the performance of the proposed silencer is preliminary researched using software simulation method, test analogy method, and some other methods to infer experiment was conducted to evaluate the experiment. During the simulation experiment, 25dB level can be reduced in the 12,500∼16,000Hz range. More than 35dB level was reduced in the 2,500∼5,000Hz range. When we used the silencer, the noise in the high frequency bands above 1,000Hz are reduced. In particular, 1,600Hz band is greatly reduced on average by 5dB. Some effective conclusions are obtained from the analysis of the experiment results, despite some uncertain factors in the experiment

This study is investigated by the analyses of modal and harmonic response on BH motor, VI motor and DH motor. The natural frequency of DH motor becomes lower than that of VI motor. As the maximum amplitude of displacement is shown to be 2.06×10-2mm at 1300 Hz in case of BH motor, BH motor can be thought to be the best structure in comparison with VI motor and DH motor. The deformation of 0.34806 mm happens at the critical frequency in case of BH motor. And the maximum deformation happens at the joint connected between screw axis and seat in cases of three kinds of motors. By applying the result of this study to the designs of these kinds of motors, it is thought that the damage of linked parts is prevented. As the durability can be examined and anticipated, this result can be utilized really

In this study, the models before and after improving the support structure of seat motor gear nut are investigated by comparing with vibration analysis. The maximum deformation model 1 becomes higher than model 2. The natural frequency of model 2 becomes higher model 1. The design model to be applied into the safe driving is useful effectively by using the analysis result of the height driving module for automotive power seat.

Various motors have been used in many cars to control the height of automotive seats. As the motor is connected with seat, it can be moved as the convenience of passenger and vibration affects passenger when motor is being driven. In this study, three models are designed. The lengths of link parts and screw axes are increased or decreased respectively in the order of models 1, 2 and 3. The case of motor is made of aluminum alloy and the rest is made of structural steel. As model 1 has the maximum amplitude displacement at 1360Hz by the basis of vibration analysis, model 1 has the most durability among three models. This study result can be effectively utilized with the design on height motor by investigating prevention and durability against its damage.

The purpose of this study is to present a case study of six sigma quality improvement practice in cooling fan motor(CFM) manufacturing processes. In this study, the CFM manufacturing process of automobile parts not relevant to the target process rate of the process point of view, in order to reduce the system to solve the problem of localized resolution procedures of six sigma DMAIC methodology was applied to study. In conclusion , this study 's field D in order to improve the initial rate of inadequate quality management best practices by applying the method of Six Sigma quality CFM failure through stabilization schemes were proposed cost reduction .To be CFM product to satisfy customers based on continuous monitoring of the effective field of claims quality management system is required.

The automotive industry in the research and development cost ratio accounted for high technology coefficient of specialization research and development budget. development and adoption of innovative technologies such as new materials technology, electronics technology, information and communications technology and new production systems is a source of competitive products. because permanent magnets without applying an external magnetic field in the BLDC motor drive system parts for EV can be supplied. it has been used in several areas. permanent magnet in the different kinds of motor parts materials is one of the key components. permanent magnet is a relatively fast rate of technological advances, changes in price is considered the fastest. in this paper, the BLDC motor parts produce by the core making method of casting method moulding analysis. moulding density was measured. As a result, the moulding density is measured 7.2~7.5g/cm2 results were excellent.

Driving mechanism, the central part of a robot, was designed in this study. Power for the motive drive was acquired by directly connecting the motor shaft in worm shape of the low-end DC motor, car window motor, to a decelerator. The decelerator consists of a worm gear to receive power from the motor shaft, a pinion gear to be connected in line with the worm gear, and an output shaft to be engaged to the pinion gear. Motion driving is achieved by the power from the motor shaft with the designed gears, transferred to the deceleration mechanism and to the output gear

The agitator with a reducer are usually using on the process of a water treatment. However, working the reducer at the field, a lubricant oil can leak out. It causes an environment pollution and a water service/sewerage pollution problem. In this study, the reducer with a drywell structure is developed in order to prevent the oil leakage. The drywell structure is that the reducer bottom housing and the support column of an output shaft are united, and taper roller bearings are in the bottom housing. During the development of the reducer, a mockup and a prototype are made by using CAD and a high speed CNC machine. Then, to prove the performance of the prototype, the performance tests, unload working test and the mechanical torque efficiency test, are conducted by the torque meter device. Also a motor velocity(rpm) control system is developed by a PID control according to the working loads(MLSS data). The results of the test are shown that the maximum torque efficiency is 88.45%, the oil leakage and the abnormal noise do not occur during the work. Therefore the reducer with the drywell structure and the motor rpm PID control system is successfully developed.

본 연구에서는 구조가 간단하고 경제적이며, 보수유지 면에서 능동형 진동제어 장치로서 매우 유리한 장점을 가지고 있는 선형모터 댐퍼(LMD : linear motor damper)를 개발하여 유니슨 기술연구소에 설치된 대형 철골구조물에 적용하였다. 개발된 LMD는 1,500kg의 가동질량을 갖고 있으며, 최대 \pm250mm의 변위로 움직일 수 있다. 제어 대상 시험구조물의 최저차 2개 진동형만을 가지는 축소모델을 사용하여 H_{\infty} 제어로직을 설계하였다. 일련의 성능 검증시험을 통해 시험 구조물의 1, 2차 진동형에 대해 가속도 레벨이 약 l0dB 감소함을 확인하였다. 본 연구를 통해 개발된 LMD가 풍 및 지진하중을 받는 구조물의 진동제어용 제진장치로서 가능성이 있음을 확인하였다.

본 논문에서는 BLDC 서보모터의 속도 제어성 향상을 위해 속도제어계에 2자유도 적분형 최적 제어법을 적용하고 그 결과를 기존의 PI제어계 및 2자유도 PI제어계와 비교하였다. 2자유도 적분형 최적제어법은 PI제어법이 갖는 지령치 추종특성과 외란 억제특성간의 트레이드오프 문제를 해결하고, 제어계의 최적성을 확보하고자 도입되어졌으며, 시뮬레이션과 실험을 통해 그 유효성을 고찰하였다. 시뮬레이션을 통해 얻은 결과는 다음과 같다. (1) 2자유도 적분형 최적제어계는 PI제어계에 비해 양호한 지령치 추종성과 외란 및 모델링 오차제거 특성을 보였다. (2) 2자유도 적분형 최적제어계는 제어파라미터인 하중행렬 Q, R 및 W에 대한 제약요건이 없을 경우, 모터의 정격조건 하에서 이들을 적절히 설정함으로써 2자유도 PI제어계보다도 양호한 지령치 추종성과 외란 및 모델링 오차 제거 특성을 얻을 수 있다. (3) 2자유도 적분형 최적제어계는 인가전압 및 전류의 크기를 2자유도 PI제어계의 그것과 동일하게 제약할 경우 2자유도 PI제어계에 비해 지령치 추종에 관한 정정시간 외에는 그다지 우수한 성능을 보이지 않았다. 또한, 실험을 통해 고찰한 PI 및 2자유도 PI제어계의 속도추종성능은 시뮬레이션 결과와 거의 동일하였다. 2자유도 적분형 최적제어계에 대한 실험결과는 논문에 나타내지 못하였으나, PI및 2자유도 PI제어계의 실험결과에서 알 수 있듯이 2자유도 적분형 최적제어계도 시뮬레이션 결과와 같은 경향을 보일 것으로 사료된다. 따라서, 본 논문에서 검토된 방법은 기존의 PI 제어계가 갖는 지령치 추종과 외란억제의 트레이드오프 문제를 상당부분 해결 가능할 것으로 보인다. 또한, 일정의 부하외란 및 모델링 오차내에서는 2자유도 PI제어계 보다 나은 제어성능을 보여 BLDC 모터의 속도 제어성 향상에 기여할 수 있을 것으로 기대가 된다. 향후, 2자유도 적분형 최적제어계의 실험결과를 통한 엄밀한 제어성능검증과 스텝외란 외의 주기성 외란 인가시 2자유도 적분형 최적제어계의 외란제거 방안 등이 검토되어야 할 것으로 사료된다.

This paper presents a design method of fuzzy controller based on TSK fuzzy model. By using the proposed method, we can design fuzzy controller mathematically, which guarantees the stability of fuzzy system. We derived a theorem related to the stability of fuzzy system. In that theorem, we show that the fuzzy system has the same stable state transition matrix as we desire. The validity of the proposed method is shown through an experiment of DC motor velocity control.

Counter balance valve is used as one part of hydraulic motor brake system. The function of this valve is to protect over-run or free falling of inertia load. But occasionally the brake system with counter balance valve makes some undesirable problems such as pressure surges or vibrations. These problems may hurt system safety and driver's conformability. Nevertheless, studies on dynamic characteristics of hydraulic system including counter balance valve are very rare, so further accumulation of research results are required. In this study, for the purpose of easy estimation about dynamic characteristics of hydraulic system including counter balance valve, precise formulation describing fluid dynamics and valve dynamics under various boundary conditions were made. The equations obtained in the preceding process include some parameters that must be got experimentally. Flow coefficients of valve and choke are the most significant ones among the parameters. So these parameters are obtained experimentally in this study, and experimental equations obtained from the experimental data were used for numerical calculation. The equations were analysed by numerical integration using Runge-Kutta method, because the equations contain various nonlinear terms. From the numerical analysis, it was verified that the dynamic response of counter balance valve and pressure variation at each elements can be estimated very easily. So the analysing method developed in this study enabled very easy estimating the relation between the performances of counter balance valve and various physical parameters related to the valve. Conclusively, it is said that the results obtained in this study can be used very usefully to develop a new type counter balance valve or to apply the valve to actual hydraulic system for various industrial equipments.