• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2408-2410
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• 2001

This paper presents the control of an underactuated two-link robot called the Pendubot. Combining linearized state feedback control with Takagi-Sugeno(T-S) fuzzy controller wide-range stabilization of Pendulum is achieved. The local stabilization controler is designed by linearinzing the dynamic equations about the several desired set point and using LQR(Linear Quadratic Regulator) techniques. Takagi-Sugeno methodology is used to control the nonlinear models near different operation points. Fuzzy controller is obtained by the fuzzy blending of the local controllers. The paper includes a description of the algorithm as well as real time experimental results for the Pendubot.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.34 no.6
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• pp.213-219
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• 1985

Superconducting Magnetic Energy Storage (SMES) system can be used for power system stabilization by absorbing or discharging active and reactive power through thyristor-comtrolled converters. In this paper, we have proposed a control algorithm that the active and reactive powers of SMES are simultaneously controlled to increase power system dynamic stability. The proposed method was applied to one machine-infinite and three machines and three load model systems. And it has been shown that the proposed algorithm is more effective in power system stabilization than the conventional one that only the active power of SMES is controlled. Eigenvalue sensitivity analysis method is introduced to estimate the optimal location of SMES in the sense of the power system oscillation mode.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.71.4-71
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• 2001

This paper presents swing up and stabilization control of an underactuated two-link robot called the Pendubot. This device is a two-link planar robot with an actuator at the shoulder, but no actuator at the elbow. The controller swings up first link from its open loop stable equilibrium point to the unstable equilibrium point and then, catches the unactuated second link to balance it there. Two control algorithms are used for this task. Proportional Derivative Control technique is used to design the swing up control. The linear model of Pendubot is obtained by linearizing the nonlinear dynamic equations about the desired equilibrium point and LQR technique is used to design a stabilization controller.

• Journal of International Academy of Physical Therapy Research
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• v.12 no.2
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• pp.2314-2322
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• 2021

Background: Back pain is associated with a high risk of recurrence. Various physical therapy techniques for back pain have been studied, including reprogramming the central nervous system by integrating sensation and motion with sensory exercise training. Objectives: To aimed verify the effectiveness of sensorimotor training in improving postural stability and pain levels. Design: A randomized controlled trial. Methods: The study population was randomized into a sensory exercise training group and trunk stabilization training group and treated three times a week for 4 weeks. Each group took part in sensorimotor training for 15 minutes or lumbar stabilization exercise for 15 minutes. Results: After the intervention both groups showed Improvements in the variables. There was a significant difference in the dynamic postural stability, limit of stability, and modified visual analog scale scores in the sensorimotor training group compared to the lumbar stabilization exercise group (P<.05). Conclusion: Sensorimotor training appears to be an effective physical therapy exercise program that can be applied in patients with low back pain to improve muscle control ability.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.11 no.1
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• pp.37-48
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• 2005

Objects: This study is designed to analysis improvement and maintaince of trunk stability targeting patients who need post operative rehabilitation exercise after undergoing opened microscopic laser discectomy(OMLD) due to HNP. Method: Between March 2004 and February 2005 a total sixty patients who underwent OMLD due to $L_4/L_5$, $L_5/S_1$ HNP and who agreed to the experiment were subject for this study. Experimental group consisted of 18 subjects, and they underwent 45 minutes dynamic lumbar stabilization exercise And control group consisted of 18 subjects who conducted conservative physical therapy based on the use of physical modality for 45 minutes except to exercise. Results: Experimental group that was lumbar extensor's isometric peak torque, weight distribution of both leg, trunk muscle balance and Oswestry LBP disability index increased during 12 weeks in a statistically significant manner compared to before exercise (p<.05). When re-test was tried, isometric peak torque (p>.05) and Oswestry LBP disability index(p<.05) maintained 12th week level or improved. Weight distribution rate of both leg and trunk muscle balance maintained the level of 8th week of exercise execution(p<.05). Control group that was lumbar extensor's isometric peak torque, weight distribution rate of both leg and trunk muscle balance aggravated during 12 weeks compared to pre-test(p>.05) But, Oswestry LBP disability index increased in a statistically significant level compared to pre-test(p<.05). When re-test was tried, isometric peak torque increased slightly compared to pre-test, but decreased when at least $60^{\circ}$ flexion angle(p>.05). Weight distribution rate of both leg and trunk muscle balance also aggravated compared to pre-test(p>.05), and Oswestry LBP disability index was similar to the 4th week of physical therapy execution(p>.05). Conclusion: Successive postoperative Especially, Application of dynamic lumbar stabilization exercise program is important than traditional lumbar strengthening exercise program in the maintaince of spinal stability.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.4
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• pp.399-405
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• 2009

The focal plane image stabilization for a satellite camera is one of the an effective method which can increase the satellite camera's image quality by removing the motion disturbance of a focal plane. The objectives of this article are to introduce the concept of the focal plane image stabilization and determine the best driving conditions of the actuator for the response and thrust. Under various driving condition the experiments have been performed to investigate the response and thrust characteristics of the piezoelectric driven stick-slip actuator of the focal plane image stabilizing device. From experiments, the best driving frequency and duty ratio for the magnesium slider are 70 kHz and 27%, respectively.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.10a
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• pp.73-77
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• 2003

Stability rating of KSR-III rocket engine is conducted based on stability rating tests in the course of development of KSR-III rocket engine. Rocket engine is approved to have combustion stabilization ability when it can suppress the external perturbation or pressure oscillation with finite amplitude and recover the original stable combustion. Rocket engine in flight nay be perturbed with unexpectedly large amplitude and thus a designer should not only assure combustion stabilization ability of the engine but also quantify the stabilization capacity. For this, several quantitative parameters and their evaluation are introduced. To verify dynamic stability of KSR-III rocket engine, five stability rating tests have been conducted. Based on these test results, such parameters are quantified and thereby, the stabilization capacity of KSR-III rocket engine is evaluated.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.2
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• pp.178-185
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• 2011

Optical image stabilization is a device to compensate the camera movement in the exposure time. The compensation is implemented by movable lens or image sensor that adjusts the optical path to the camera movement. Generally, the camera is moved by a handshake, thus the handshake is considered as an external disturbance. However, there are many other vibrations such as car and train vibration. In this paper, the optical image stabilization system in high frequency region is presented. Notch filter and lead compensator are designed and applied to improve the stability without changing the actuator. To verify the performance of the optical image stabilization system in high frequency region, the experiment equipment with moving object is established. It is confirmed that the opticalimage stabilization system does not diverge at the resonance frequency.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.7 no.2
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• pp.23-39
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• 2001

Dysfunction of the anterior and dorsal muscles of the trunk have been studied in relation to low back pain of many years. Many muscles of the trunk are capable of contributing to the stabilization and protection of the lumbar spine, recent evidence has suggested that transversus abdominis may be critically involved and has been the focus of rehabilitation. The delay in onset of contraction of trunk muscles associated with movement of the upper or lower limb in patients with low back pain indicates a significant deficit in the automatic motor command for control of disturbance to the spine. The function of transversus abdominis has been largely ignored in the evaluation of spinal stabilization and protection. The most essential stabilizing muscles for the lumbar column are the transversus abdominis and the multifidus. Sling exercise therapy(SET) concept consists of a system of diagnosis and treatment. The system of diagnosis involves testing the muscle's tolerance through progressive loading in open and close kinetic chains. The SET system contains elements such as relaxation, increasing the range of movement, traction, training the stabilizing musculature, sensorimotor exercises, training in open and close kinetic chains, dynamic training of the mobilizing musculature, cardiovasc+ular exercises, group exercise, personal exercise at home. Sensorimotor training is an essential element of the SET concept. The emphasis is on closed kinetic chain exercises on an unstable surface, thereby achieving optimum stimulation of the sensorimotor apparatus.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4D
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• pp.671-678
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• 2006

In this study, to describe vehicle-structure dynamic interaction phenomena with 1/4 vehicle model, nonlinear Hertzian contact spring and nonlinear contact damper are adopted. The external loads acting on 1/4 vehicle model are selfweight of vehicle and geometry information of running surface. The constraint equation on contact surface is implemented by the Penalty method with stabilization and the reaction from constraint violation. To describe pitching motion of various vehicles two types of the displacement constraint equations are exerted to connect between car bodies and between bogie frames, i.e., the rigid body connection and the rigid body connection with pin, respectively. For the time integration of dynamic equations of vehicles and structure Newmark time integration scheme is adopted. To reduce the error caused by inadequate time step size, adaptive time-stepping technique is also adopted. Thus, it is expected that more versatile dynamic interaction phenomena can be described by this approach and it can be applied to various railway dynamic problems with low computational cost.