• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.3 s.22
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• pp.92-100
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• 2005

The objective of this paper is to design a sliding mode controller of an electro-mechanical fin actuation system using extended reducer-observer(ERO) which is used in order to estimate the velocity. The employed observer enables proper estimation of the plant state variables, even in the case of the constant or slow varying load torque disturbances. The effectiveness of this control scheme is verified by comparison with a PID control through a series of simulation studies. The simulation results show that the sliding mode control designed with the ERO gives good control performances.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.3
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• pp.154-160
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• 2004

In this paper, a combined field orientation and adaptive backstepping approach using a sliding mode adaptive flux observer, is proposed for the control of induction motor In order to achieve the speed regulation with the consideration of improving power efficiency, rotor angular speed and flux amplitude tracking objectives are formulated. Rotor flux and inverse time constant are estimated by the sliding mode adaptive flux observer based on a fixed stator frame model and mechanical lumped uncertainty such as inertia moment, load torque disturbance, friction compensated by the adaptive backstepping based on a field-oriented model. Simulation results are provided to verify the effectiveness of the proposed approach.

• Journal of Power Electronics
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• v.6 no.2
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• pp.172-177
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• 2006

This paper presents the sliding mode observer of an induction motor for the fuel cell electric vehicles. The exact rotor flux estimation of the induction motor is important for achieving the best performance from the fuel cell electric vehicle system. However, the flux estimator of the induction motor control is highly sensitive to the voltage sensor output characteristics and system parameter variation influenced by external factors. In order to eliminate these problems, this paper investigates the electric vehicle performance due to parameter variation of the induction motor. A new method to estimate the fuel cell electric vehicle system is proposed based on the sliding mode observer.

• Proceedings of the KIEE Conference
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• 2004.07e
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• pp.33-36
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• 2004

In this paper, a new estimation algorithm for the rotor speed for SRM drives is described. The algorithm is implemented by the sliding mode observer. The stability and robustness of the sliding observer for the parameter variations of the SRM are proved by variable structure control theory. Variable speed control of the SRM is accomplished by the estimated speed. Experiment results verify that the sliding mode observer is able to estimate the speed.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.12
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• pp.1305-1311
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• 2004

This study presents a mathematical model and a sliding mode observer of the injection system for common rail diesel engines. The injector model consists of three subsystems: the actuator subsystem, the mechanical subsystem, and the hydraulic subsystem. In the actuator subsystem, the constitutive relations of piezoelectricity are used to model the actuator made up of piezoelectric material. Based on the proposed model, the observer estimates the injection rate and injection timing, and can play a vital role of sensorless control of fuel injection in the near future. The sliding mode theory is applied to the observer design in order to overcome model uncertainties. The injector model and observer are evaluated through the injector experiments. The simulation results of the injector model are in good agreement with the experimental data. The sliding mode observer can effectively estimate the injection timing and the injection rate of the injector.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.10
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• pp.949-958
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• 2012

Position tracking control of a link of a slave manipulator which needed to track the corresponding link of a master manipulator was addressed in this paper. Since driving torque from motor is transmitted through a set of flexible cable to link, the motion control system is modeled by a two-mass model connected with elastic coupling which has finite stiffness. Relative vibration of two-mass resonant system is a serious problem to operate manipulator. This paper proposed sliding mode control to reduce resonant vibration and fine position tracking control. Also, a pseudo-sliding mode control which uses a saturation function instead of a signum function was discussed and showed that the pseudo-sliding mode control can improve disturbance regulation performance as well as guarantees fine command tracking without chattering which is an inherent drawback of basic sliding mode control. In addition, a disturbance observer based sliding mode control has been suggested to improve disturbance regulation performance. The feasibility of the proposed control design was verified along with some simulation results.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.10
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• pp.587-594
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• 2005

An adaptive observer for rotor resistance is designed to estimate rotor flux for the a-b model of an induction motor assuming that rotor speed and stator currents are measurable. A singularly perturbed model of the motor is used to design an Adaptive sliding mode observer which drives the estimated stator currents to their true values in the fast time scale. The adaptive observer on the sliding surface is based on the equivalent switching vector and both the estimated fluxes and the estimated rotor resistance converge to their true values. A speed controller considering the effects of parameter variations and external disturbance is proposed in this paper. First, induction motor dynamic model at nominal case is estimated. based on the estimated model, speed controller is designed to match the prescribed speed tracking specifications. Then a dead-time compensator and a robust controller are designed to reduce the effects of parameter variations and external disturbances. the desired speed tracking control performance can be preserved under wide operating range, and good speed load regulating performance. Some simulated results are provided to demonstrate the effectiveness of the Proposed controller.

• Journal of the Society of Naval Architects of Korea
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• v.61 no.4
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• pp.216-225
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• 2024

The sliding mode controller has characteristics that ensure stability and robustness against system uncertainty and disturbance. However, chattering occurs in the control inputs to compensate for system uncertainties and ensure that the system operates efficiently on the sliding surface. When the disturbance is large, using a sliding mode controller requires a large control gain value, which also increases chattering and reduces performance. Therefore, in this study, a nonlinear disturbance observer was used to compensate for external disturbances such as currents and waves and uncertainty in the control system for autonomous underwater vehicles. Accordingly, a robust controller can be implemented while reducing the control gain. The disturbance observer serves to ensure that the behavior of the actual system is closer to the nominal model by compensating for uncertainties between the actual system model and the nominal model during the control process. Therefore, the simulation results show that the performance and robustness of the autonomous underwater vehicle controller are improved by introducing a disturbance observer.

• Journal of Power Electronics
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• v.14 no.1
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• pp.125-134
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• 2014

This paper presents a robust and speed-sensorless stator flux estimation for induction motor direct torque control. The proposed observer is based on sliding mode approach. Stator electrical equations are used in the rotor orientation reference frame to eliminate the observer dependence on rotor speed. Lyapunov's concept for systems stability is adopted to confine the observer gain. Furthermore, the sensitivity of the observer to parameter mismatch is recovered with an adaptation technique. The nonlinearities of the pulse width modulation voltage source inverter are estimated and compensated to enhance stability at low speeds. Therefore, a new method based on the model reference adaptive system is proposed. Simulation and experimental results are shown to verify the feasibility and effectiveness of the proposed algorithms.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.6
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• pp.58-63
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• 2010

In this paper, distributed tension observer for R2R process is proposed. The minimal order observer theory is utilized to design the distributed tension observer. The proposed method estimates the tension of a specific sub-process based on the speed and tension information from its adjacent sub-processes. Utilizing its properties, the proposed method can be applied to decentralized control structure. In order to achieve high estimation accuracy, sliding mode technique is also adopted to the proposed method.