• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1355-1360
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• 1990

This paper describes the application of the recently developed feedback linearization technique to the design of a new command to line-of-sight (CLOS) guidance law for skid-to-turn (STT) missiles. The key idea lies in converting the three dimensional CLOS guidance problem to the tracking problem of a time-varying nonlinear system. Then, using a feeedback linearizing approach to tracking in nonlinear systems, we design a three dimensional CLOS guidance law that can ensure zero miss distance for a randomly maneuvering target. Our result may shed new light on the role of the feedforward acceleration terms used in the earlier CLOS guidance laws. Furthermore, we show that the new CLOS guidance law can be computationally simplified without performance degradation. This is made possible by dropping out the terms in the new CLOS guidance law, which obey the well-known matching condition.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.10
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• pp.563-571
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• 2000

In this paper, a nonlinear adaptive control method for an EMS(Electro-Magnetic Suspension) system with mass uncertainty is proposed. Using the coordinate transformation and feedback linearizing control, EMS system has been transformed into the form of parametric strict-feedback system with unknown virtual control coefficients. With this transformed system, tuning functions approach, which is an advanced from of adaptive backstepping, has been applied in order to stabilize the system against mass uncertainty. Computer simulation is also carried out in order to compare the performance of the proposed controller with that of feedback linerizing controller.

• Proceedings of the KIEE Conference
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• 1990.11a
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• pp.10-14
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• 1990

Variable Structure System(VSS) la being extended to a new control system of ac servo machines for its merits of simple mechanism and robustness. This paper has studied about applying VSS to position control for brushless servo motor. But VSS has the chattering problem of control input. This chattering phenomenon cause acoustic noises, torque ripple and increase harmonics of the current. One of the useful way to eliminate this defect of VSS, linearlizing the switching function is discussed here. Though the conventional method of linearizing the switching function diminishes the chattering, it may degrade the robustness of the system. In this paper, new linearized switching function which shows robust performance to the parametric variation and reduces chattering simultaneously is introduced and assured by simulation.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.72-76
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• 1997

Interior permanent magnet synchronous motors can be applied to applications requiring wide-speed operation. The current control scheme of an interior permanent magnet synchronous (IPM) motor via feedback linearizing technique is proposed. As the available voltage controlling the armature current is small in transient operations and/or flux-weakening region, the current control performance can be deteriorated. The high performance overmodulation strategy is also proposed to improve the current responses. The control performances are confirmed by simulations.

• Journal of Electrical Engineering and information Science
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• v.1 no.2
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• pp.58-66
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• 1996

An adaptive input-output linearization technique of an interior permanent magnet synchronous motor with a specified output dynamic performance is proposed. The adaptive parameter estimation is achieved by a model reference adaptive technique where the stator resistance and the magnitude of flux linkage can be estimated with the current dynamic model and state observer. Using these estimated parameters, the linearizing control inputs are calculated. With these control inputs, the input-output linearization is performed and the load torque is estimated. The adaptation laws are derived by the Popov's hyperstability theory and the positivity concept. The robustness and the output dynamic performance of the proposed control scheme are verified through the computer simulations.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.1
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• pp.1231-1239
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• 2001

This paper presents a new leveling algorithm that estimates the initial horizontal angles composed of roll angle and pitch angle for a moving or stationary vehicle. The system model of the EKF is designed by linearizing the nonlinear Euler angle differential equation. The measurement models are designed for the moving case and for the stationary case, respectively. The simulation results show that the leveling algorithm is ade-quate not only for acquiring the initial horizontal angles of the vehicle in the motion with acceleration and rotation but also for the stationary one.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.366-369
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• 1991

A nonlinear controller based on feedback linearization method is proposed for an electromagnetic suspension system. After exactly linearizing the system with nonlinear feedback, linear control technique is applied. Modeling of stagger typed magnet is introduced and controlled for not only levitation, but guidance. By the feedback linearization, the nonlinear, MIMO system is linearized and decoupled, so we can use linear control law. The simulation of this system control skim is demonstrated. Robustness properties of the proposed controller with respect to the load variations and external disturbance is also analyzed for a multi input multi output system. In this properties, the boundary of variation is proposed.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.508-511
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• 1991

In this paper, we have analyzed the transient and steady state characteristics of buck type DC-DC converter using the sliding mode control method based upon VSS. This control method provides the easier analysis tool due to the time domain analysis and the acquirement of desired transient characteristics if the slope of the switching line is properly selected, and guarantees the robustness against parameter uncertainties and load disturbances. Also, it can achieve direct nonlinear control without linearizing approximation of state space averaging method. PSPICE simulation results are then presented verifying these concepts.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.6
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• pp.971-981
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• 1994

In this paper, we consider feedback-linearizing control of VR (Variable Reluctance) motors which have been increasingly used in high performance direct-drive applications. We characterize all torque controllers that can make the generated torque of a VR motor linear to torque command but without torque ripple. The torque controlles maximize the range of torque commands which are admissible under the physical limitation in stator currents. The whole class of all such torque controllers is parameterized in the explicit form which contains a function to be chosen freely. This free function can be used to achieve other control objectives as well as linear dynamic characteristics. As the examples for optimal choices of the free function, we actually determine two optimal free functions, one for minimal rate of change in current commands and the other for minimal power loss due to stator resistance. To illuminate further the practical use of torque controllers proposed in this paper, we present some experimental results for the case of a commercially available VR motor.

• Proceedings of the KIEE Conference
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• 1997.07b
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• pp.418-421
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• 1997

A control synthesis scheme is presented for nonlinear single-input-single-output (SISO) systems with parametric uncertainty which have completely unstable zero dynamics. The approach involves the derivation of an input-output linearizing control law which achieves internal stability for a nonlinear minimum phase approximation to the original system using Fliess normal form. A vector of unknown constant parameters is also considered. A Lyapunov-based additional control law is shown to stabilize the full system.