• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.11
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• pp.1-10
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• 1996

In this paper, we suggest a new identification method based on the takagi-sugeno fuzzy model which prepresents an envrionmental stiffness and propose a method to decide PD gains of the PD controller. It is difficult to perform a compliance task due to characteristics of robot itself and uncertain work envronment. Therefore, in this paper, we identify the fuzzy rule by dividing the relationship of input-output data into several piecewise-linear equations using the hough transform which is the one this fuzzy model, we propose a method to design the pD gain. We show the validity of this method by the experiment of tracking the surface of the paper box as an example of variable environment using robot manipulator and force sensing system. As a performance index, we use the settling time, and perform an analysis between conventional PD contorllers and this controller.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.496-499
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• 1991

Photovoltaic system has very low energy conversion efficiency and the output characteristics of solar cell is varied by the Insolation quantity and the temperature. In order to improve the efficiency of photovoltaic system, the energy which has got from solar cell must be use maximum. In this paper, it was stimultaneous executed both MPPT control and instrumentation in order that the operating point of solar cell is located maximum power point, using the PWM inverter and micro-computer, which is for the purpose of acquiring maximum power from the solar cell. As a result, maximum power point tracking had carried out and the efficiency of photovoltaic system improved, even if insolation quantity and the temperature are varied.

• Proceedings of the KIEE Conference
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• 1999.11c
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• pp.530-532
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• 1999

In adaptive fuzzy control, system designer develops an adaptive law for the output of the unknown plant to track a given signal. The adaptation gains of the adaptive law are critical elements in the overall system, however, they were used to be selected by the designer's experience or intuition. In this paper, genetic algorithm is used to search an optimal adaptation gain and simulation results will be presented to show the improved tracking responses.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.187-189
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• 2006

In mechanical system, gear trains have backlash innately. With the presence of inherent backlash, the overall system performance is limited in many practical control systems. It has been reported that a disturbance observer has the property of effective removing disturbance and cutting measurement noise off. The plant is remodeled with modified disturbance observer to observe and compensate backlash characteristics. And this paper describes a method to design Q filter and to analyze the effects of disturbance and measurement noise to the output. It is shown that the vibration and tracking error caused by backlash were decreased and the time constant and relative degree are important factor to design Q filter.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.197-200
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• 2001

본 논문에서는 특정한 형태의 제약 즉, 매니퓰레이터의 자유도와 주어진 제약조건의 차원의 차이가 1이며, 매니퓰레이터의 동역학을 작업영역에서의 축차모델로 나타내었을 때, 변환행렬이 단위행렬로 나타나는 제약을 가지는 불확실한 로봇 매니퓰레이터의 위치/힘 추종을 위한 적응제어기를 제안한다. 제안된 제어기는 비선형 좌표변환을 통하여 얻어진 로봇의 축차모델(reduced-order model)을 이용하여 위치제어와 힘제어의 문제를 분리한다. 특히, 비선형 동적 필터를 이용하여 위치의 측정만을 필요로 하며, 적응제어 기법을 통하여 전역 점근적인 안정성을 보장한다.

• Journal of Ocean Engineering and Technology
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• v.20 no.6 s.73
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• pp.18-23
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• 2006

This paper introduces the results of the development of a new mobile digital DC-arc welding machine (DDWM). A simple PI controller is applied to the DDWM to control the output welding current that is tracking the constant setting current. Furthermore, a hot-start function, an anti-stuck function, a standby mode and an intelligential circuit breaker (ICB) are included in the DDWM. The DDWM increases welding quality and saves more power energy than a conventional welding machine. The DDWM is changed from ready mode into the standby mode, automatically, after 2-minute intervals from this unload start. Then, the DDWM is changed into ready mode, automatically, since it is reused for welding. Moreover, the DDWM increases welding quality, productivity and reduces costs of welding. So, the DDWM can make a considerable contribution to the mobile welding industries. The effectiveness of the DDWM was proven by the experimental results.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.93-98
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• 1989

This paper describes the application of the recently developed feedback linearization technique to designing a new Command to Line-of-Sight (CLOS) guidance law. We show that the CLOS guidance problem can be formulated as a tracking problem. Then, using the feedback input-output linearization technique, we find a new 3dimensional CLOS guidance law that can assure zero miss distance for a randomly maneuvering target. It sheds light on the feedforward acceleration compensation terms used in the conventional CLOS guidance laws to improve the performance. To illustrate further the significance of our result, simulation results are given.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.686-691
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• 2001

In this paper, the pneumatic service robot with a hybrid type is developed. A pneumatic has the advantage of good compliance, high payload-to-weight and payload-to-volume ratios, high speed and force capabilities. Using pneumatic actuators which have low stiffness, the service robot can guarantee safety. By suggesting a new serial-parallel hybrid type for the service robot which separates into positioning motion and orienting motion, we can achieve large workspace and high strength-to-moving-weight ratio at the same time. A sliding mode controller can be designed for tracking the desired output using the Lyapunov stability theory and structural properties of pneumatic servo systems. Through many experiments of circular trajectory, the pneumatic service robot is evaluated and verified.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.71-72
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• 2006

This paper introduces the results of the development of a new mobile Digital DC-arc Welding Machine (DDWM). A simple PI controller is applied to the DDWM to control the output welding current tracking the constant setting current. Furthermore, a hot-start function, an anti-stuck function, a standby mode and an intelligential circuit breaker (ICB) are included in the DDWM. The DDWM increases welding quality and saves more power energy than a conventional welding machine. Because the DDWM is changed from ready mode into the standby mode automatically after 2 minutes interval from this unload start. Then the DDWM is changed into ready mode automatically since it is reused to weld. Mover, the DDWM increases welding qualify, productivity and reduces costs of welding. So, the DDWM can have a great of contribution to the mobile welding industries. The effectiveness of the DDWM was proven by the experimental results and durable test.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.192-194
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• 2006

Backlash between meshing gear teeth causes impact, tracking error and undesired vibrations. It is usually minimized by precision gear, spring-loaded anti-backlash gears and precise mechanical adjustment. Although these techniques can help to reduce the backlash gap, its cost is relatively high and performance is limited. And the classic controller is insufficient to control the dynamic system with nonlinearity. For these reason, a fuzzy controller is proposed to compensate the backlash effect at a robot system. The input variables are position error and change in error. The output variable can be defined by input voltage of motor. The performance of a fuzzy controller is verified by comparing with a PID controller. The results show that the undesired vibration is suppressed. And then diminishing the position error is observed.