• 전력전자학회논문지
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• 제15권5호
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• pp.361-368
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• 2010

본 논문에서는 스테핑 전동기의 고속 위치제어기를 제안하였다. 제안된 위치제어기는 폐루프 및 오픈루프 제어모드를 모두 가지고 있으며, 위치 제어를 위해 직접 토크 각도를 제어하는 방식을 적용하였다. 제안된 스테핑 전동기의 위치제어기는 고속 운전상태에서 위치결정 오차를 감소시키기 위해 메모리에 속도에 따른 내장된 토크 각도와 PI 제어기를 통하여 토크각도를 결정하는 폐루프 제어모드로 동작한다. 제안된 폐루프 제어모드에서 메모리에 내장된 토크각도는 선행적으로 속도에 따른 전동기의 토크각도를 룩-업 테이블로 저장하여 제어량을 결정하게 되므로, 빠른 응답특성을 가지게 되며, 부하 및 관성에 따른 위치오차는 PI 제어기의 제어량에 의해 보상되어질 수 있다. 또한, 저속 운전상태와 정지상태에서는 3가지로 구분된 오픈루프 제어모드가 각각 잔여 위치오차를 보정하게 되며, 급속 정지상태에서의 다이나믹 브레이크 동작을 지원하게 된다. 제안된 위치제어기는 2상 스테핑 전동기의 실시험을 통하여 그 성능을 검증하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.565-568
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• 1995

This paper presents the position control of a closed-loop cylinder system using ER(electro-rheological)valve actuators. Following the field-dependent pressure analysis of the ER valve actuators on the basis of Bingham model of ER fluids, a 3 d.o.f. close-loop sylinder system having the heave, roll and pitch motions is proposed. The governing equations of motion are derived using Lagrange's equation, and a control model is established by considering system uncertain parameters such as load conditions. A sliding mode controller which has inherent robustness to system uncertainties is adopted to achieve robust tracking control performance. Tracking control results for sinusoidal trajectory were presented in order to demonstrate the effectiveness of the proposed control system.

• 대한전기학회논문지
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• 제36권4호
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• pp.267-272
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• 1987

In this paper, field oriented control is applied to a 16 bit micro-processor Mc68000 controlled CSI fed induction motor servo drive. The control of induction motor using the principle of its is able to have the transient performance nearly to that of DC motors in the position control. The software and hardware for the Mc68000 is developed. The position control scheme consists of the field oriented control loop and te speed reference pattern generator. The digital computer simlation and experimental results are provided, close agreement between them is obtained.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1786-1790
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• 2004

The main objective of this paper is to analyze the performance of various force control algorithms in improving and adjusting the compliance of industrial robots in contact with their environment. Some of fundamental force control algorithms such as sensorless control, impedance control and hybrid position/force control are theoretically analyzed and simulated for various situations of an environment, and then a series of experiments using them were performed. In this paper, a control scheme to use position control in implementing the impedance control was investigated in order to nullify the effect of joint friction. The new reference trajectory is generated using contact force feedback and original desired trajectory. And an inner position control loop is designed to provide accurate position tracking for the new reference trajectory and good disturbance rejection. Experiments to insert a peg in a hole (so-called the peg-in-a-hole task) were performed with HILS (hardware-in-theloop simulation) system based on the results of the analyses and simulations on the characteristics of each control algorithm. The experiments showed that various force control methods improved the performance of robots in close contact with the environment by adjusting their compliance with respect to an arbitrary set of coordinates.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 추계학술대회 학술발표 논문집
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• pp.187-190
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• 1998

The values of physical components of the plants and controllers as well as the relevant environmental conditions change in time, thus the output performance can be deteriorated during the operating span of the system. Naturally the duty of calibration or the prevention of performance deterioration due to excessive component sensitivity should be provided to the control system. The proposed controller, whenever necessary, measures the open-loop and close-loop characteristics, and then calculates the offset and sensor gain correction values based on the prepared standard measurements It is applied to the control of a flexible link system with the gain and offset calibration problems in the light sensor module for position to show the applicability. In this paper, we propose a digital controller which has the capability of calibration gain and offset adjustment using fuzzy methods.

• Journal of Power Electronics
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• 제13권6호
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• pp.964-974
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• 2013

A modified direct torque control (DTC) method based on torque angle is proposed for interior permanent-magnet synchronous motor (IPMSM) drivers used in electric vehicles (EVs). Given the close relationship between torque and torque angle, proper voltage vectors are selected by the proposed DTC method to change the torque angle rapidly and regulate the torque quickly. The amplitude and angle of the voltage vectors are determined by the torque loop and stator flux-linkage loop, respectively, with the help of the position of the stator flux linkage. Furthermore, to satisfy the torque performance request of EVs, the nonlinear dead-time of the invertor caused by parasitic capacitances is considered and compensated to improve steady torque performance. The stable operation region of the IPMSM DTC driver for voltage and current limits is investigated for reliability. The experimental results prove that the proposed DTC has good torque performance with a brief control structure.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1034-1036
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• 2004

The most basic form of a direct-drive linear motor is the voice coil motor(VCM). The voice coil motor employs a stationary permanent magnet field assembly in conjunction with a moving coil winding assembly to produce a force proportional to the current applied to the coil. Voice coil motor provide motion capable of extremely fine position sensitivity, limited only by the feedback sensor used to close the control loop. This paper presents dual-servo voice coil motor for improvement of driving range and position resolution. The voice coil motor is a cylindrical shape to improve reliability of a nanoindenter.

• International Journal of Control, Automation, and Systems
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• 제2권4호
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• pp.536-541
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• 2004

It is important to estimate and calibrate sensor errors in maintaining the performance level of SDINS. In this study, an estimation technique of fixed sensor errors for SDINS calibration is discussed. First, the fixed errors of gyros and accelerometers, excluding gyro biases are estimated by the navigation information of SDINS in multi-position. The SDINS with RLG includes flexure errors. In this study, the gyros flexures are out of consideration, but the proposed procedure selects certain positions and rotations in order to minimize the influence of flexures. Secondly, the influences of random walks, flexures and orientation errors are verified via numerical simulations. Thirdly, applying the previous estimated errors to SDINS, the estimation of gyro biases is conducted via the additional control signals of close-loop self-alignment. Lastly, the experiments illustrate that the extracted calibration parameters are available for the improvement of SDINS.

• Journal of Power Electronics
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• 제18권2호
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• pp.432-444
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• 2018

This paper presents a capacitor voltage balancing topology using a three-level boost converter (TLBC) for a neutral point clamped (NPC) three-level inverter fed surface permanent magnet synchronous motor drive (SPMSM). It enhanced the performance of the drive in terms of its voltage THD and torque pulsation. The main attracting feature of the proposed control is the boosting of the input voltage and at the same time the balancing of the capacitor voltages. This control also reduces the computational complexity. For the purpose of close loop vector control, a software based cost effective resolver to digital converter RDC-less estimation is implemented to calculate the speed and position. The proposed drive is simulated in the MATLAB/SIMULINK environment and an experimental investigation using dSPACE DS1104 validates the proposed drive system at different operating condition.

• 전자공학회논문지SC
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• 제44권5호
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• pp.62-70
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• 2007

본 논문에서는 일정 토크영역에서 승압형 PFC 컨버터와 직접토크제어(DTC) 방법을 사용하여 BLDC 모터의 구동 시스템을 DSP(TMS320F2812)로 구현하였다. 기존의 6단계 PWM 전류제어와 달리 미리 정한 샘플시간 마다 간단한 look-up 표로부터 2상 도통 모드에 대한 인버터의 전압 상태 벡터를 설정함으로써 원하는 전류파형을 만들었으며 이로부터 기존의 전류제어기보다 훨씬 빠른 토크 응답특성을 얻을 수 있었다. 또한 BLDC 모터의 비 이상적인 사다리형 역기전력에 의해 발생되는 저주파 토크변동을 저감하기 위하여 위치 loop-up 표를 사용하였다. 아울러 역률을 보정하기 위해 승압형 PFC 컨버터를 구성하였고 이 때 전파 정류된 입력전압과 출력전압, 인덕터의 전류에 의해 평균전류모드 제어 방식으로 80 kHz마다 PWM 듀티(duty)가 조절 되도록 하였다. 이와 같이 복잡한 제어 알고리즘은 초고속 DSP의 출현으로 PFC와 DTC 알고리즘이 동시에 제어가 가능하며, 본 논문에서는 DTC 알고리즘을 구현할 때 DSP의 일반 범용의 출력포트를 사용하여 구현하였고 단지 PFC에서만 1개의 PWM을 사용하여 디지털 제어기를 구현하였다. 실험을 통해 DTC 알고리즘과 PFC 컨버터를 이용한 BLDC 모터 구동 시스템의 타당성과 효용성을 보였고, 실험결과로부터 PFC 컨버터를 사용하지 않았을 때는 역률이 약 0.77이었으나 PFC 컨버터를 사용하였을 때는 부하변동에 관계없이 약 0.9997로 크게 향상됨을 확인하였다.