• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.424-427
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• 2009

This paper reposes a novel tracking algerian for efficiency improvement of photovoltaic(PV) system using sensor method PV system of sensor method is exactly impossible to track a sun position when insolation is low or rapidly changed by the clouds and fogs. Also, in this case, tracking device is occurred energy consumption by unnecessary operating. This statement of reason, real power of PV system is not increased than fixed PV system in specified location. Therefore, this paper proposes a novel ticking algorithm considered insolation for efficiency improvement of PV system using sensor method And this paper analyzes the generation volume and proves the validity of proposed algorithm as compared with the conventional PV tracking system using sensor method.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.40 no.5
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• pp.308-316
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• 2003

This paper describes a tracking control for the mobile robot based on fuzzy systems. The conventional back-stepping controller includes the dynamics and kinematics of the mobile robot, which is affected by the derived velocity reference by a kinematic controller. To improve the performance of conventional back-stepping controller, this paper uses the fuzzy systems known as the nonlinear controller. In this paper, the new velocity reference for the back-stepping controller is derived through the fuzzy inference. Fuzzy rules are selected for gains of the kinematic controller. The produced velocity reference has properly considered the varying reference trajectories. And simulation results show that the proposed controller is more robust than the conventional back-stepping controller.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.786-791
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• 2003

This paper proposes an adaptive control algorithm for nonholonomic mobile robots with unknown parameters and the proposed control method is used in numerical simulations for applying to a practical twowheeled welding mobile robot(WMR). The proposed adaptive controller to track an arbitrary given welding path is designed by using back-stepping technique and is derived for a nonlinear model under the assumption such that the system parameters are partially known. Moreover, the proposed adaptive control system is stable in the sense of Lyapunov stability. Inertia moments of system are considered to be unknown parameters and their values can be estimated simply by using update laws proposed in an adaptive control scheme of this research. The simulation results are provided to show the effectiveness of the accurate tracking capability of the proposed controller for two-wheeled welding mobile robot with a smooth curved reference welding path.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.4
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• pp.277-282
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• 2002

This paper proposes a nonlinear adaptive controller based on back-stepping method for tracking reference substrate concentration by manipulating dilution rate in a continuous baker's yeast cultivating process in stirred tank bioreactor. Control law is obtained from Lyapunov control function to ensure asymptotical stability of the system. The Haldane model for the specific growth rate depending on only substrate concentration is used in this paper. Due to the uncertainty of specific growth rate, it has been modified as a function including the unknown parameter with known bounded values. The substrate concentration in the bioreactor and feed line are measured. The deviation from the reference is observed when the external disturbance such as the change of the feed is introduced to the system. The effectiveness of the proposed controller is shown through simulation results in continuous system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.226-229
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• 2001

Radio signal tracking has been developed especially in military as well as in other industries. It is necessary that an adaptive system trace the signal varying its PRI and frequency. In this paper we proposed a system to adapt various PRI and frequency using a neural network model named Error Back Propagation. Fist we prepared learning data by separating signal into time intervals and did some experiments with the teaming data. We found that the system had good effectiveness in tracing varying PRI and frequency signals.

• Proceedings of the KIEE Conference
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• 2009.04b
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• pp.219-221
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• 2009

This paper analyzes efficiency of photovoltaic(PV) tracking system using solar location algorithm(SLA). Solar location tracking system is needed for efficiently and intensively using PV system independent of environmental condition. PV tracking system of program method is presented a high tracking accuracy without the wrong operating in rapidly changed insolation by the clouds and atmospheric condition. Therefore, this paper analyzes efficiency of PV system using SLA for more correct position tracking of solar. Also, controlled altitude angle and azimuth angle by applied algorithm is compared with data of korea astronomy observatory. And this paper analyzes the tracking error and proves the validity of applied algorithm.

• Journal of Electrical Engineering and Technology
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• v.9 no.2
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• pp.707-720
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• 2014

This paper proposes a face tracking scheme that is a combination of a face detection algorithm and a face tracking algorithm. The proposed face detection algorithm basically uses the Adaboost algorithm, but the amount of search area is dramatically reduced, by using skin color and motion information in the depth map. Also, we propose a face tracking algorithm that uses a template matching method with depth information only. It also includes an early termination scheme, by a spiral search for template matching, which reduces the operation time with small loss in accuracy. It also incorporates an additional simple refinement process to make the loss in accuracy smaller. When the face tracking scheme fails to track the face, it automatically goes back to the face detection scheme, to find a new face to track. The two schemes are experimented with some home-made test sequences, and some in public. The experimental results are compared to show that they outperform the existing methods in accuracy and speed. Also we show some trade-offs between the tracking accuracy and the execution time for broader application.

• Smart Structures and Systems
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• v.3 no.2
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• pp.147-172
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• 2007

The present paper is concerned with the design of distributed sensors and actuators. Strain type sensors and actuators are considered with their intensity continuously distributed throughout a continuous structure. The sensors measure a weighted average of the strain tensor. As a starting point for their design we introduce the concept of collocated sensors and actuators as well as the so-called natural output. Then we utilize the principle of virtual work for an auxiliary quasi-static problem to assign a mechanical interpretation to the natural output of the sensors to be designed. Therefore, we take the virtual displacements in the principle of virtual work as that part of the displacement in the original problem, which characterizes the deviation from a desired one. We introduce different kinds of distributed sensors, each of them with a mechanical interpretation other than a weighted average of the strain tensor. Additionally, we assign a mechanical interpretation to the collocated actuators as well; for that purpose we use an extended body force analogy. The sensors and actuators are applied to solve the displacement tracking problem for continuous structures; i.e., the problem of enforcing a desired displacement field. We discuss feed forward and feed back control. In the case of feed back control we show that a PD controller can stabilize the continuous system. Finally, a numerical example is presented. A desired deflection of a clamped-clamped beam is tracked by means of feed forward control, feed back control and a combination of the two.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.3
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• pp.403-411
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• 2015

In this paper, we propose a design method for the position and speed controller, current control of a Brushless Direct Current(BLDC) motor using back-stepping design techniques. Further, to stabilize the whole system, and proposes a method for setting the appropriate gain control to improve the tracking performance. By applying the proposed controller to 120W BLDC motors were tested for the ability to follow the position, velocity and current reference. Since the simulation results of the steady state error is within 1%, we were able to show the usefulness of the tracking performance of the proposed controller.

• 정보저장시스템학회:학술대회논문집
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• 2005.10a
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• pp.229-234
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• 2005

A novel method to measure the interaction movement, focusing direction and tracking direction in an optical pick-up, is proposed and the decoupling control for it is discussed. First, the basic principle of the coupline analysis method using back electromotive farce is introduced. Second, the interaction analysis between focusing direction and tracking direction fur commercial slim type actuator is performed using the proposed method. Finally, the coupling analysis and decoupling control for the slim type optical pick-up are discussed. From the brief simulation, we shows that the effectiveness and validity of the proposed method.