• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.1846-1847
• /
• 2011

In this paper, for the trajectory tracking control of mobile robot, firstly, we obtained the T-S fuzzy models from the tracking-error models, one of which has nonlinear form and the other is linearized around the reference trajectory. Then the tracking control inputs are designed using the proposed fuzzy linearization method and the existed PDC method. Lastly, the tracking performance is tested and compared for each model through simulation.

• Proceedings of the KIEE Conference
• /
• 2008.10b
• /
• pp.462-463
• /
• 2008

This paper proposes a method for dynamic output-feedback controller design for stochastic time-delay systems. Based on recent results on time-delay systems control, a tractable and delay-dependent design condition is proposed, which provides a dynamic output-feedback controller to render the closed-loop stochastic time-delay systems to be asymptotically stable in the mean-square sense. The feasibility problem of the proposed condition is recast into a cone complementarity problem. An algorithm adopting cone complementarity linearization is presented to solve the resulting problem.

• Proceedings of the KIEE Conference
• /
• 2007.04c
• /
• pp.194-197
• /
• 2007

This paper proposes a linearization technique for the 3 level NPC type inverter, which increases the linear control range of inverter up to the 6-step inverter. The overmodulation range is divided into two modes depending on the modulation index(MI), In mode I, the reference angles are derived from the Fourier series expansion of the reference voltage corresponds to the MI. In mode II, the holding angles are also derived in the same way. Therefore, it is possible to obtain the linear control and the maximized utilization of PWM inverter output voltage.

• Proceedings of the KIPE Conference
• /
• 2008.06a
• /
• pp.634-636
• /
• 2008

This paper proposes a frequency detection method based on an advanced zero-crossing technique. Zero-crossing method for detecting frequency is one of the most widely used methods today. Although it is simple to apply, it requires extra hardware in implementation due to its limitations in accuracy. The proposed method models the error generated during zero crossing linearization and compensated for it in real time which makes it simple and accurate. The validity of the method and its applicability in anti-islanding detection of distributed generators was confirmed through simulation.

• Journal of the Optical Society of Korea
• /
• v.15 no.4
• /
• pp.321-328
• /
• 2011

Various methods have been investigated to increase photon density in soft tissue, an important factor in low-level laser therapy. Previously we developed a compression-controlled low-level laser probe (CCLLP) utilizing mechanical negative compression, and experimentally verified its efficacy. In this study, we used Bezier curves to numerically simulate the skin deformation and photon density variation generated by the CCLLP. In addition, we numerically modeled changes in optical coefficients due to skin deformation using a linearization technique with appropriate parameterization. The simulated results were consistent with both human in vivo and porcine ex vivo experimental results, confirming the efficacy of the CCLLP.

• International Journal of Control, Automation, and Systems
• /
• v.3 no.spc2
• /
• pp.270-277
• /
• 2005

In this paper, a decentralized control problem is considered for multimachine power systems with nonlinear interconnections and disturbances. A direct feedback linearization compensator is employed to cancel most of the nonlinearities, and then a backstepping procedure is applied to deal with the interconnections and to reduce the effects of a disturbance that does not satisfy the matching condition. In this procedure, the disturbance is handled by using a smooth approximation of the signum function. Practical stability is achieved under the assumption that the infinite norm of the disturbance is known. However, even in the case where the infinite norm of the disturbance is not known precisely, the proposed control system still guarantees $L_2$ stability. Furthermore, the origin is globally uniformly asymptotically stable in the absence of the disturbance. A three-machine power system is considered as an application example.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.1005-1007
• /
• 2005

A Nonlinear approach to control of Small Scale Rotary Wing Unmanned Aerial Vehicle (R-UAV) is presented. Using Backstepping, a globally stabilizing control law is derived. We derive backstepping control law for angle of attack and sideslip control. The inherent nonlinear nature of the system are considered here which helps in naturally stabilizing without extensive external effort. Thus, the resulting control law is much simpler than if the feedback linearization had been used.

• Proceedings of the KIEE Conference
• /
• 1999.07b
• /
• pp.693-695
• /
• 1999

In this paper, the adaptive nonlinear state observer is proposed to estimate the internal states and the nonlinearities of 4-cylinders 4-cycles spark ignition(SI) engines. The observed states and nonlinearities will be used to design the adaptive feedback linearization controller for reducing the fluctuation of idle speed. The simulation results are represented to show the validity of the proposed nonlinear observer-based adaptive controller.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.5 no.1
• /
• pp.65-70
• /
• 2000

An approximated analytical solution of mathematical model for the three phase fluidized bed bioreactor (TFBBR) was proposed using the linearization technique to describe oxygen utilization rate in wastewater treatment. The validation of the model was done in comparison with the experimental results. Satisfactory agreement was obtained in the comparison of approximated analytical solution and numerical solution in the oxygen concentration profile of a TFBBR. The approximated solutions for three modes of the liquid phase flow were compared. The proposed model was able to predict the biomass concentration, dissolved oxygen concentration the height of efficient column, and the removal efficiency.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.63 no.11
• /
• pp.1594-1601
• /
• 2014

In this paper, we propose the LQ servo control method for the automatic train control of urban rail vehicle. Structures of the conventional PID control and LQ servo controller are compared in order to demonstrate the simplicity of the proposed controller which doesn't have zeros of the closed loop systems. The energy consumption is dealt with as an object function to be minimized, which consists of the quadratic performance indices for optimal control with the input of the feedback linearization. The effectiveness of the proposed method is shown by the practical example, compared with the conventional PD controller.