• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.2
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• pp.285-290
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• 2013

The slotless linear synchronous motor(LSM) has the advantages that the structure of the mover is simple and it can control the trust force ripple by make the magnetic energy in a gap uniform by removing a slot of the primary iron core. Also, the application of the transportation system is becoming expansion because it high efficiency drive is possible and compares with the other LSM as control is more excellent. However, the application of the living field was unsatisfactory. Therefore, in this study, we examined the drive characteristics by the position feedback control for the living field application of the slotless LSM and we prove useful of the controller through load loading and the acceleration changing to get minimization of the speed vibration and stable answer characteristics.

• Journal of Drive and Control
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• v.13 no.1
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• pp.18-26
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• 2016

This research is conducted to develop an automatic steering system for parallel parking, and the performance of the system was evaluated by parallel parking a conventional vehicle. The automatic steering system consisted of MDPS (motor driven power steering) to control steering, ESC (electronic stability control) to acquire wheel speed, ultrasonic sensors to recognize the parking space, and a controller to communicate and handle data. The parallel parking process using the automatic steering control consisted of parking space recognition, parking path generation, and parking path tracking. The path for parallel parking was generated based on a kinematic model of a conventional vehicle, and a PI controller was used to control the steering angle for path tracking. Parallel parking using the automatic steering control was conducted according to vehicle speed conditions. The results show that the errors on the x-axis and y-axis were below 0.54 m and 0.14 m, respectively, and the error on the steering angle was less than $1^{\circ}$. Therefore, it is possible to implement parallel parking using an automatic steering control system for conventional vehicles.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.8
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• pp.17-25
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• 1998

Aluminum alloys have low density, relatively high strength and yield strength, good plasticity, good machinability, and high corrosion and acid resistance. Therefore, they are suitable for large containers for the food, chemical and other industries. Large containers are often bodies of revolution consisting of shell courses, stiffening rings, heads and other elements joined by annular welds. Larger containers have longer welds and require greater leak-tightness and higher weld mechanical properties. The LNG tank consists of aluminum plates with various sizes, so its construction should by divided by several sections. Moreover, each section has its own sub-section consisted of several aluminum plates. To guarantee the quality of huge LNG tank, therefore, the precise control of plate dimension should by urgently needed in conjunction with the appropriate selection of process parameters such as cutting speed, depth of cut, rotational speed and so on. In this paper, a manufacturing system was developed to implement automatic circular tracking in height direction and automatic circular interpolation in depth of cut direction. Also, the neural network based on the backpropagation algorithm was used to predict the cutting quality and motor load related with the life time of the developed system. It was revealed that the manufacturing system and the neural network could be effectively applied to the bevelling process and to predict the quality of machined area and the motor load.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.488-493
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• 2005

In gun stabilization systems, the torque comes from the unbalance mass of gun and the base acceleration is an important source of disturbance which degrades stabilization performance. Fatigue of gear train is another important factor affecting structural safety problems. In this paper, a feedback control gain is designed by optimal control weighting to difference between motor and gun velocity, and a feedforward controller using FXLMS algorithm is adopted to investigate those problems. Experimental results show that the feedforward compensator based on FXLMS can reduce the disturbance effects. The directional convergence property according to initial conditions of the FXLMS is also shown through experiments.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.1
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• pp.116-123
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• 2004

The demand for the stable and comfortable cabin of a high speed passenger ship is increasing. The study on shipboard comfort has been mainly concentrated on the motion control of a whole hull body. In this study, however, a new control system operated by two parallel robots (3RPS, 3SPR) such as the active suspension system of motor vehicle is proposed. The goal of this control is keeping zero velocity of the upper robot (cabin) although the lower robot (ship) is moving by the waves. Jacobian matrix was used to design the controller, From the simulation results, the remarkable reduction of motion of the cabin (upper platform) was observed. The 3SPR parallel robot shows better performance compared to the 3RPS robot.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.12 s.177
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• pp.34-41
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• 2005

There is a strong demand fur the contactless transportation device fur a hard disk and silicon wafer without contaminating and damaging them. To fulfill this requirements, A transportation device fur them has been proposed. But the device needs many of costly displacement sensors positioned along the transportation interval and possesses a very complicated controller and driving scheme. To overcome those kinds of drawback, in this paper, we present a very simple and cost-effective transportation device which only consists of a linear guide, very simple electrostatic suspension system and driving circuit of stepping motor. The principle of stable suspension by relay feedback control, derivation of lateral restoring force, the design of transportation system are described, fellowed by the experimental system. Experimental results show that a 3.5-inch hard disk has been transported with a speed of approximately 20mm/s while being suspended stably at a gap of 0.25mm.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.16-18
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• 2003

In a switched reluctance motor drive, it is important to synchronize the stator phase excitation with the rotor position, because the position of rotor is an essential information. In the high-speed region, switching angles are fluctuated back and forth out of the preset value, which is caused by the sampling period of the microprocessor. In this paper, a low cost analog encoder suitable for practical applications is proposed. The validity of the proposed analog encoder with a proper logic controller is verified from the experiments.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1992.11a
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• pp.41-46
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• 1992

고전적인 제어 기법들을 이용한 전동기의 속도 제어기는 하나의 고정된 동작점에 대해서 대개 양호한 동작 특성을 얻을 수 있으나 전동기 매개변수의 섭동 및 부하 외란의 존재시 규정된 제어 동작을 유지하기가 어렵다는 단점을 갖고 있다. 따라서 본 연구에서는 이러한 단점을 극복하기 위하여 적응 제어 기법중의 하나인 기준 모델 적응 제어 (Model Reference Adaptive Control : MRAC) 방식을 직류 전동기의 속도 제어에 적용하였으며 또한, 2차 이상인 전동기의 속도 제어 시스템을 1차로 저차화시켜 제어 알고리즘의 계산에 소요되는 시간을 줄임으로써 실시간 제어가 가능토록 하였다. 제시된 기준 모델 제어 기법과 PI 제어 기법을 직류 전동기의 속도 제어에 각각 적용하고 부하의 관성변화에 다른 속도 응답 특성을 실험을 통하여 비교 검토하였다.

• 한국전산유체공학회:학술대회논문집
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• 2005.10a
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• pp.87-91
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• 2005

A conceptual design for the movable roll vane system is done for the roll stability control of KSLV-I. The control effectiveness of the roll vanes is estimated using the numerical simulation. The hinge location is selected to minimize the torque requirement at the maximum dynamic pressure condition, and the maximum torque of 3.0 kN-m is found to be required to actuate the roll vanes for the entire range of operation. An electro-mechanical actuator system which is composed of a DC motor, the speed reducers, the battery package and the controller is designed using the given requirements, the maximum torque of 3.0 kN-m, the maximum deflection angle of 25 deg. and the maximum angular velocity of 30 deg/sec. More detailed design to make more compact and highly efficient system will be done in the future.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.954-958
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• 2004

본 논문은 부하에 대한 빠른 응답특성을 보이는 새로운 토폴로지를 제안하였다. PI제어기 출력이 포화될 때 windup 현상이 나타나고 그 결과로 성능이 저하된다. 따라서 전동기의 가변속 제어성능을 위해 가속시에는 개선된 Anti-windup PI제어기만을 사용하고, 감속시에는 추가로 부하의 특성을 고려하여 braking 동작을 사용하였다. 시뮬레이션 및 실험결과는 속도성능면에서 제안된 방식이 종래의 다른 제어방식에 비해 우수함을 보여 준다.