• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.93-97
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• 1988

The sliding mode control is an effective method to establish robustness against parameter variations and disturbance. But, in sliding mode strategy, the control function is discontinuous on the hyperplane. Consequently, the control input chatters at high frequency. When we apply such a control to the induction motor drive system, that causes a torque ripple and current harmonics, which are harmful to the system. In this paper, we introduce a low pass filter between sliding mode control output and driver input to overcome that problem. The band-width of this filter is varied according to the error funtion to improve transient responses.

• 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.

• ETRI Journal
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• v.38 no.5
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• pp.1008-1018
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• 2016

This paper presents a control scheme for the leader-following formation of multiple robots. The control scheme combines the sliding mode control (SMC) method with the nonlinear disturbance observer (NDOB) technique. The formation dynamics suffer from uncertainties because the individual robots are uncertain. Concerning such formation uncertainties, the leader-following formation dynamics are modeled. Assuming that the formation uncertainties have an unknown boundary, an NDOB-based observer was designed to estimate the formation uncertainties. A sliding surface containing the observer outputs has been defined. Regarding the sliding surface, an SMC-based controller was investigated to form uncertain robots. A sufficient condition in the sense of the Lyapunov theory was proven such that the formation system is asymptotically stable. Herein, some comparison results between the sole SMC method and the second-order SMC method are presented to demonstrate the effectiveness and feasibility of the control scheme for multiple robots in the presence of uncertainties.

• Journal of Electrical Engineering and Technology
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• v.10 no.6
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• pp.2393-2405
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• 2015

This paper considers a decentralized multiple faults detection and isolation (FDI) scheme for reconfigurable manipulators. Inspired by their modularization property, a global sliding mode (GSM) based stable adaptive fuzzy decentralized controller is investigated for the system in fault free, while for the system suffering from multiple faults (actuator fault and sensor fault), the decentralized sliding mode observer (DSMO) is employed to detect their occurrence. Hereafter, the time and location of faults can be determined by a fault isolation scheme via a bank of DSMOs. Finally, the effectiveness of the proposed schemes in controlling, detecting and isolating faults is illustrated by the simulations of two 3-DOF reconfigurable manipulators with different configurations successfully.

• Journal of the Korea Institute of Military Science and Technology
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• v.4 no.2
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• pp.179-188
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• 2001

The objective of this paper is to design and implement sliding mode control scheme for an actuation system using BLDC motor. Since the dynamic characteristics of this system with unknown disturbance and parameter variations are very complicated and highly nonlinear, the conventional linear control approaches may not guarantee satisfactory control performances. In order to improve the dynamic performances of this system, a model following sliding mode control(MFSMC) with perturbation estimation approach is designed and implemented. It eliminates the conventional requirements for the knowledge of uncertainty upper boundary. The effectiveness of this control approach is verified by comparison with a PID control through a series of simulation and experimental studies.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.106-108
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• 2005

The calculation of parameters of a process model is modified to find that better sliding mode controller for a process with time delay. A design method by Camacho has such problems as chattering, overshoot due to the Pade approximation errors for the time delay term of the first order model. In this paper, a new design technique for a sliding mode controller is proposed by introducing the modified Pade approximation considering the weight factor. The modified method is expected to provide a more accurate model with better control settings.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.67.2-67
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• 2001

In the adaptive fuzzy sliding mode control, from a set of fuzzy IF-THEN rules adaptive fuzzy sliding mode control whose parameters are adjusted on-line according to some adaptation laws is constructed for the purpose of controlling the plant to track a desired trajectory. Most of the research works in nonlinear controller design using fuzzy systems consider the affine system with fixed grid-rule structure based on system state availability. The fixed grid-rule structure makes the order of the controller big unnecessarily, hence the on-line fuzzy rule structure and fuzzy observer based adaptive fuzzy sliding mode controller is proposed to solve system state availability problems. Therefore adaptive laws of fuzzy parameters ...

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.6
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• pp.519-525
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• 2012

Electric brake booster systems replace conventional pneumatic brake boosters with electric motors and rotary-todisplacement mechanisms including ECU (Electronic Control Unit). Electric booster brake systems require precise target pressure tracking and control robustness because vehicle brake systems operate properly given the large range of loading and temperature, actuator saturation, load-dependent friction. Also for the implement of imbedded control system, the controller should be selected considering the limited memory size and the cycle time problem of real brake ECU. In this study, based on these requirements, a sliding mode controller has been chosen and applied considering both model uncertainty and external disturbance. A mathematical model for the electric booster is derived and simulated. The developed sliding mode controller considering chattering problem has been compared with a conventional cascade PID controller. The effectiveness of the controller is demonstrated in some braking cases.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.522-527
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• 2013

In this study, dynamic response control of a flexible wing such as gust loads alleviation using sliding mode control method is presented. To achieve this purpose, trailing edge control surface of a flexible wing is used as control means generating the aerodynamic control force. Aeroservoelastic CASE) model consisting of aeroelastic plant, control surface actuator model, and gust model depicting the atmospheric turbulence is formulated in the state space. A sliding mode controller based on the estimated state vector is designed for active dynamic response control of flexible wing aeroservoelastic model. The performance of the controller designed is demonstrated via numerical simulation for the representative flexible wing model under atmospheric turbulence loading.

• International Journal of Precision Engineering and Manufacturing
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• v.5 no.4
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• pp.14-20
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• 2004

In this work, a new control methodology to achieve accurate position control of an AC servo motor subjected to external disturbance is proposed. Unlike conventional sliding mode controller which requires a prior knowledge of the upper bound of external disturbance, the proposed technique, called sliding mode controller with disturbance estimator (SMCDE), can offer robust control performances without a prior knowledge of the disturbance bound. The SMCDE is featured by an integrated average value of the imposed disturbance over a certain sampling period. By doing this, undesirable chattering phenomenon in the estimation process can be effectively alleviated. The benefits of the proposed control methodology are empirically demonstrated on AC servo motor and control responses are evaluated through a comparative work between the proposed and conventional control schemes.