• Proceedings of the KIPE Conference
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• 2001.12a
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• pp.115-118
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• 2001

This paper presents a new sensorless control scheme using simple duty signal feedback technique in DC-DC converters. The proposed sensorless control scheme (DFC) has the characteristics that they show the same as operation performance of current mode control by using duty feedback technique without current sensor as well as present better dynamic response performance than conventional sensorless current mode control (SCM) in case that input source is perturbed by step change or DC input source includes the . harmonics. Also, the proposed control scheme has good noise immunity and simple control circuits since they have one feedback loop, and can be applied to all DC-DC converters. The concept and control principles of the proposed control scheme are explained in detail and the validity of the proposed control scheme is verified through several interesting simulated results.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.466-471
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• 1994

To make a dynamic system a given desired motion trajectory, a new feedback error learning scheme is proposed which is based on the repeatability of dynamic system motion. This method is composed of feedforward and feedback control laws. A benefit of this control scheme is that the input pattern that generates the desired motion can be formed without estimating the physical parameters of system dynamics. The numerical simulations show the good performance of the proposed scheme

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1253-1256
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• 1996

In this paper, a new nonlinear feedback linearization control scheme for induction motors is developed. The control scheme employs a fuzzy nonlinear identification scheme based on fuzzy basis function expansion to adoptively compensate the parameter variations, i.e. rotor resistance, mutual and self inductance etc. An important feature of the proposed control scheme is to incorporate the sliding mode controller into the scheme to speed up convergence rate. Simulation tests show the robust behavior of the proposed controller in the presence of the parameter uncertainties of the machine.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.3
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• pp.29-38
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• 1998

This ppaer suggests a congestion control scheme for CL(ConnectionLess) overlay network using the feedback loops getween CL werver, between CL servers, and the header translation table of CL server. The CL overlay network for CBDS(Connectionless Broadband Data Service) defined by ITU0T(International Telecommunication Union-Telecommunication) consists of CL servers which route frames and links which connect between CL user and CL server or between CL servers. In this CL overlay network, two kinds of congestions, link congestion and CL server congestion, may occur. We suggest a scheme that can solve the congestion using ABR(Available Bit Rate) feedback control loop, the traffic control mechanism. This scheme is the link-by-link method suing the ABR feedback control loops between CL user and CL server or between CL servers, and the header translation table of CL server. As CL servers are always endpoints of ABR connections, the congestion staturs of the CL server can be informed to the traffic sources using RM(Resource Management) cell of the ABR feedback loops. Also CL server knows the trafffic sources making congestion by inspecting the source address field of CLNAP-PDUs(ConnectionLess Network Access Protocol - Protocol Data Units). Therefore this scheme can be implemeted easily using only both ABR feedback control loop of ATM layer and the congestion state table using the header translation table of CL server because it does not require separate feedback links for congestion control of CL servers.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.6
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• pp.554-562
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• 2002

This paper presents a new sensorless control scheme using simple duty signal feedback technique in DC/DC converters. The proposed Duty Feedback Control(DFC) has the characteristics that they show the same as operation performance of current mode control by using duty feedback technique without current sensor as well as present faster dynamic response performance than conventional Sensorless Current Mode(SCM) control in case that input source is perturbed by step change or DC input source includes the harmonics. Also, the proposed control scheme has good noise immunity and simple control circuits since they have one feedback loop, and can be applied to all DC/DC converters. The concept and control principles of the proposed control scheme are explained in detail and the validity of the proposed control scheme is verified through several interesting simulated and experimental results.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.197-200
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• 1996

This paper considers feedback error learning neural networks for robot manipulator control. Feedback error learning proposed by Kawato [2,3,5] is a useful learning control scheme, if nonlinear subsystems (or basis functions) consisting of the robot dynamic equation are known exactly. However, in practice, unmodeled uncertainties and disturbances deteriorate the control performance. Hence, we presents a robust feedback error learning scheme which add robustifying control signal to overcome such effects. After the learning rule is derived, the stability is analyzed using Lyapunov method.

• Honam Mathematical Journal
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• v.16 no.1
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• pp.103-109
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• 1994

Piezoceramic patches as collocated actuator and sensors are widely used in mechanical control systems. An approximation scheme for computing feedback gains arising in heat flux stabilization problem with such control mechanism is introduced. The scheme is based on a finite element method and a variational approach.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.8
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• pp.883-892
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• 1992

In order to remove the assumption of full state availability which is one of the major difficulties with the practical realization of variable structure control system (VSCS), an output feedback variable structure control scheme for multivariable systems is proposed. The proposed output feedback VSCS is composed of a switching surfaces with dynamic structure and a new output feedback control input that can be constructed by using conventional output feedback control input design methodologies. With the proposed scheme, the practical realization of VSCS for the systems with unmeasurable states and for high order systems that conventional schemes cannot be applied is possible. Simulation results show that proposed scheme is a viable method to achieve the desired control performance, for example, good transient response, robustness against process parameter variations and external disturbance without measuring all the state variables.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.4
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• pp.787-793
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• 2015

In order to support reliable medium access control (MAC) layer multicast services in Broadband Wireless Access (BWA) networks, we here propose spreading codes (Cumulative ACK (CA) code and ARQ Feedback Request (AFR) code) based reliable multicast feedback scheme. The status indications based on the automatic repeat request (ARQ) mechanism are needed in some multicast services. In accordance with various wireless channel environments, we demonstrate the performance excellency of our proposed scheme with respect to required uplink resources compared with the original feedback scheme based on unicast ARQ feedback messages. In addition, we analyze packet error rate (PER) against the various wireless channel environments.

• Journal of Power Electronics
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• v.9 no.2
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• pp.288-299
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• 2009

This paper proposes a feedback linearization control scheme of AC/DC PWM converters with LCL input filters using no damping resisters. Feedback linearization techniques use a transformation from nonlinear system models into equivalent linear models in a simpler form. The feedback linearization scheme in this work has cascade structures unlike usual feedback linearization, therefore it has an advantage that it is possible to limit the capacitor current to a certain level. The performance of the proposed controller is validated with simulation and experimental results.