• Journal of Power Electronics
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• 제9권4호
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• pp.654-666
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• 2009

Direct torque control (DTC) of induction machines (IM) is a well-known strategy of these drives control which has a fast dynamic and a good tracking response. In this paper a nonlinear DTC of speed sensorless IM drives is presented which is based on input-output feedback linearization control theory. The IM model includes iron losses using a speed dependent shunt resistance which is determined through some effective experiments. A stator flux vector is estimated through a simple integrator based on stator voltage equations in the stationary frame. A novel method is introduced for DC offset compensation which is a major problem of AC machines, especially at low speeds. Rotor speed is also determined using a rotor flux sliding-mode (SM) observer which is capable of rotor flux space vector and rotor speed simultaneous estimation. In addition, stator and rotor resistances are estimated using a simple but effective recursive least squares (RLS) method combined with the so-called SM observer. The proposed control idea is experimentally implemented in real time using a FPGA board synchronized with a personal computer (PC). Simulation and experimental results are presented to show the capability and validity of the proposed control method.

• Journal of Power Electronics
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• 제5권1호
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• pp.20-28
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• 2005

This paper presents a fuzzy predictive sliding mode control for high performance induction motor position drives. A new simplified inner-loop sliding-mode current control scheme based on a nonlinear mathematical model of an induction motor is introduced. Novel predictive fuzzy logic PI and PID controllers are used in speed and position loops, respectively. Sliding-mode current controllers and fuzzy predictive logic controllers are designed based on indirect vector control. The overall system performance is examined under different dynamic operating conditions. The performance of the drive system is robust and stable, and insensitive to parameters and operating condition variations even though non-exact system parameters are used in the implementation of the proposed controllers.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 춘계학술대회 논문집 에너지변화시스템부문
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• pp.149-151
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• 2009

Hybrid electric vehicle has three operating mode, depending on the operation of the engine and electric motor. According to the speed range of BLDC motor, In hybrid traction mode, both the engine and electric motor deliver to drive train. Battery charge mode, the electric motor operates as generator and is driven by the engine to charge the batteries. In engine alone traction mode, the electric motor is do-energized, and vehicle is propelled by the engine alone. we propose hysteresis current control technique to maintain constant speed in the motor load torque at the reverse direction. The proposed method is verified by using Matlab Simulink software.

• 수산해양교육연구
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• 제29권3호
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• pp.778-784
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• 2017

This paper proposes a sensorless speed control of a permanent magnet synchronous motor (PMSM) based on an adaptive sliding mode observer (SMO) for electric propulsion system of small ships. An adaptive observer gain is proposed based on the Lyapunov's stability criterion to reduce the chattering problem at any speed operation instead of the constant gain observer. Furthermore, a cascade low-pass filter with variable cut-off frequency is suggested to strengthen the filtering capability of the observer. The experimental results from a 1.5 kW PMSM drive are provided to verify the effectiveness of the proposed adaptive SMO. The result shows that the proposed method gives good speed control performances even when the PMSM operates at 0.5% from its rated speed value.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1738-1743
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• 2004

This paper presents an automobile traction control system by using a sliding mode controller with disturbance observer for estimating the car-body speed. First, we show that the control system, which combines an automobile system and a disturbance observer, can be divided into a controllable system and an estimated one. And, we found out that the effect of the traction control and ABS depends on the air resistance of the car. Then, the sliding mode control system is designed using the obtained combined system. And finally, the stability of this control system is verified by simulation and it shows a very satisfactory results.

• 동력기계공학회지
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• 제19권4호
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• pp.89-96
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• 2015

This paper investigates some strategies to overcome the chattering problem of the conventional sliding mode observer (SMO) and to improve the rotor position estimation performance for full range sensorless control of a PMSM. An adaptive observer gain based on the Lyapunov's stability criterion and a cascade low pass filter with advanced phase delay compensation were proposed to reduce the chattering problem and to strengthen the filtering capability of the SMO. Several cases studies through experiments were carried out to confirm conventional SMO's problems and effectiveness of the proposed strategies. The experimental results show that the proposed method gives precise estimation on speed and rotor position when the motor rotates on 2% of its rated speed.

• 한국산업융합학회 논문집
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• 제19권2호
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• pp.81-87
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• 2016

This paper presents a new approach to control of stable motion of single wheel driving robot system of a pitch that is controlled by an in-wheel motor and a roll that is controlled by a reaction wheel. This robot doesn'thave any actuator for a yaw axis control, which makes the derivation of the dynamics relatively simple. The Lagrange equations was applied to derive the dynamic equations of the one wheel driving robot to implement the dynamic speed control of the mobile robot. To achieve the real time speed control of the unicycle robot, the sliding mode control and optical regulator are utilized to prove the reliability while maintaining the desired speed tracking performance. In the roll controller, the sigmoid-function based robust controller has been adopted to reduce the vibration by the situation function. The optimal controller has been implemented for the pitch control to drive the unicycle robot to follow the desired velocity trajectory in real time using the state variables of pitch angle, angular velocity, angle and angular velocity of the driving wheel. The control performance of the control systems from a single dynamic model has been illustrated by the real experiments.

• 제어로봇시스템학회논문지
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• 제4권4호
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• pp.525-533
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• 1998

A conventional contact type brake system which uses a hydraulic system has mny Problems such as time delay response due to pressure build-up, brake pad wear due to contact movement, bulky size, and low braking performance in high speed region. As vehicle speed increases, a more powerful brake system is required to ensure vehicle safety and reliability. In this work, a contactless brake system of an eddy current type is proposed to overcome problems. Optimal torque control which minimizes a braking distance is investigated with a scaled-down model of an eddy current type brake. It is possible to realize optimal torque control when a maximum friction coefficient (or desired slip ratio) corresponding to road condition is maintained. Braking force analysis for a scaled-down model is done theoretically and experimentally compensated. To accomplish optimal torque control of an eddy current type brake system, a sliding mode control technique which is, one of the robust nonlinear control technique is developed. Robustness of the sliding mode controller is verified by investigating the braking performance when friction coefficient is varied. Simulation and experimental results will be presented to show that it has superior performance compared to the conventional method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1784_1785
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• 2009

This paper presents sliding mode control and optimal control techniques for controlling the speed of permanent magnet synchronous motor. Virtual sliding surface has nominal dynamics of an original system. The performance of the system with sliding mode control and optimal control is compared with the response of the nominal system. As a result, the sliding mode control and optimal control has robustness against the system uncertainties.

• 융합신호처리학회논문지
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• 제2권2호
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• pp.89-94
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• 2001

본 논문에서는 로봇 매니플레이터의 고속 동작시 위치 제어의 정확성을 감소시키는 다중 모드 오차 진동을 제거 할 수 있는 단순한 슬라이딩 모드 제어를 소개한다. 또한 시스템의 파라메터 변화와 외란으로 인해 슬라이딩 평면 조건의 깨짐을 방지하기 위해 신경망 학습 기능이 사용되어 진다. 그러므로 본 논문에서는 신경망을 이용한 슬라이딩 모드 제어시스템이 설계되고, 제안된 제어 시스템의 성능은 시뮬레이션 을 통해 증명된다.