• Journal of Institute of Control, Robotics and Systems
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• v.4 no.2
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• pp.163-169
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• 1998

In this paper, we design an optimal model following ${\mu}-$synthesis control system for fuel-injection of diesel engine which has robust performance and satisfactory command tracking performance in spite of uncertainties of the system. To do this, we give gain and dynamics parameters to the weighting functions and apply genetic algorithm with reference model to the optimal determination of the weighting functions that are given by the D-K iteration method which can design ${\mu}-$synthesis controller in the state space. These weighting functions are optimized simultaneously in the search domain which guarantees the robust performance of the system. The ${\mu}-$synthesis control system for fuel-injection designed by the above method has not only the robust performance but also a better command tracking performance than those of the ${\mu}-$synthesis control system designed by trial-and-error method. The effectiveness of this ${\mu}-$synthesis control system for fuel-injection is verified by computer simulation.

• 정보저장시스템학회:학술대회논문집
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• 2005.10a
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• pp.223-228
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• 2005

In oprical disk drives, surface defects on a disk distort tracking error signal and disturb a precision tracking control.. A conventional method against disk defect is held the tracking control signal when a defective portion is detected. However, if the defective portion is getting longer, objective lens will get away from following track. In order to keep the postion of spot from following track, the servo system must predict tracking error and control the object lens in the defective portion. A tracking control system for optical disk drives was proposed recently based on both Coprime Factorization(CF) and Zero Phase Erro. Tracking(ZPET) control. The system was proposed for overcome the limit of previously tracking error. But there were no research about the method against the defective portion. This paper proposes a new and simple ZPET construct. as a new method against the defective portion. From experimental results, we have proved that proposed method improves the performance against the defective portion, decreases the uncertainty of a model, and requires less memory than the previously proposed method.

• Journal of Yeungnam Medical Science
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• v.39 no.4
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• pp.332-335
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• 2022

We report on changes in the ascending reticular activating system (ARAS) concurrent with the recovery of impaired consciousness following rehabilitation and cranioplasty in a patient with traumatic brain injury (TBI), which were demonstrated on diffusion tensor tractography (DTT). A 34-year-old male patient was diagnosed with a traumatic intracerebral hemorrhage after falling from a height of approximately 7 m and underwent a right frontoparietotemporal decompressive craniectomy and hematoma removal. At 5 months after onset, when starting rehabilitation, the patient showed impaired consciousness, with a Glasgow Coma Scale (GCS) score of 4. Comprehensive rehabilitative therapy was provided until 14 months after onset, and his GCS score improved to 8. Cranioplasty was performed using auto-bone at 14 months after onset. One month after cranioplasty, his GCS score improved to 12. On the 15-month DTT, the deviated lower dorsal ARAS was restored on both sides, and the right side had become thicker. The right lower ventral ARAS was reconstructed, and increased neural connectivity of the upper ARAS was detected in both the prefrontal cortices. Thus, changes in the ARAS were demonstrated in a patient with TBI during recovery of consciousness following rehabilitation and cranioplasty.

• Journal of Biosystems Engineering
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• v.27 no.5
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• pp.417-424
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• 2002

This study was conducted to develop a vehicle, leading or following a worker at a certain distance to assist laborious transporting works in greenhouses. A prototype vehicle was tested in the practical field conditions using a developed control algorithm. Results of this study were summarized as following: 1. The sensing device consisted of infrared sensors was attached to the front of the vehicle and turning following algorithm was developed to make the vehicle turned as it follows a worker simultaneously. 2. The measured average power consumptions were 110W and 89W, equivalent to 5.2-6.4 hrs battery durations, at low speed with and without the maximum payload, respectively. 3. Results of the travel tests showed that the deviations from the center of row spacing were $\pm$100 mm along the ridge and $\pm$85 mm along the hydroponic bed in the greenhouse. Therefore, the worker-following transport vehicle was feasible to travel along the row without collision in the greenhouse.

• Journal of Acupuncture Research
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• v.17 no.3
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• pp.75-86
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• 2000

Objectives : This study is to applied effectively to the acupuncture treatment for disorders following whiplash injuries. Methods : This study suggests five various ways and principtes of treating disorders following whiplash injuries by means of acupuncture. First principle is that acupuncture treatment is carried out on acupoint far from cervical spine at acute stage, on the other hand, Extraordinary Vessel and other acupuncture treatment such as five element acupuncture treatment is applied at chronic stage in order to control balance disoders due to cervical pathology. Second is acupuncture treatment will be performed in group of three part of Meridian System-Yangmyung, Taeyang, Soyang-according to cervical kinetic, its characteristic and location of pain. Third is acupuncture treatment could be performed on basis of theory of Eohyel-disorders and disturbance of blood circulation. Fourth is to decrease tension of SCM muscle, because disorders following whiplash injuries has much association to injury of CM muscle and is simillar to tension syndroms of SCM muscle. fifth is taping therapy could control and decrease disorders following whiplash injuries based on spiral balance taping theory. Conclusions : These results suggest that acupuncture treatment for disorders following whiplash injuries will significally decrease pain and control syndrom caused by cervical disorder.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.8
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• pp.682-690
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• 2002

This paper presents an output feedback controller design method for uncertain linear systems with sinusoidal disturbance of uncertain frequencies. The controller needs to compensate for the performance deterioration due to the uncertain frequencies of sinusoidal disturbance. To this end, we introduce a virtual system including the dynamics corresponding to the uncertain frequencies and design a controller which minimizes the output difference between the virtual system and the closed-loop system. In other words, the controller is designed so that the closed-loop system approximates the virtual system. The feedback controller is achieved by solving an LMI optimization problem involving a robust $H_{\infty}$ constraint. The advantages of the proposed design method are examined by comparing it with a design method that only minimizes the $H_{\infty}$ norm of the transfer function between the sinusoidal disturbance and the output. The proposed design method is applied to the track-following system of rewritable optical disk drives and is evaluated through an experiment.

• The Journal of Korea Robotics Society
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• v.6 no.1
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• pp.86-96
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• 2011

The human-following is one of the significant procedure in human-friendly navigation of mobile robots. There are many approaches of human-following technology. Many approaches have adopted various multiple sensors such as vision system and Laser Range Finder (LRF). In this paper, we propose detection and tracking approaches for human legs by the use of a single LRF. We extract four simple attributes of human legs. To define the boundary of extracted attributes mathematically, we used a Support Vector Data Description (SVDD) scheme. We establish an efficient leg-tracking scheme by exploiting a human walking model to achieve robust tracking under occlusions. The proposed approaches were successfully verified through various experiments.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.394-396
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• 2005

In this paper, we propose an adaptive tracking control method of a mobile manipulator for contour following with a kinematic model to have several unknown dimension parameters. Moreover, we will use the decentralized control method to design two independent controllers for two subsystems. The proposed controllers in this paper are based on the Lyapunov function in order to guarantee the stability of whole system for contour following task. The updated laws are also designed to estimated the unknown dimension parameters. Finally, the simulation results are presented to show the validity of the proposed controllers in this paper.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.9 s.90
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• pp.827-836
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• 2004

In this paper, we design a robust multi-objective track-following controller that satisfies transient response specifications and diminishes the influence of sinusoidal disturbance. To this end, a robust control problem with the multiple constraints is considered. We show that a sufficient condition satisfying the robust control problem can be expressed by linear matrix inequalities. Finally, the robust track-following controller can be designed by solving an LMI optimization problem. The effectiveness of the proposed controller design method is verified though experiments.

• Journal of Biomedical Engineering Research
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• v.15 no.2
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• pp.209-216
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• 1994

The objective of the research reported in this paper is to design locomotion system of the motorized wheelchair, to develope the wall following algorithm. The indoor navigation of a motorized wheelchair can be based on the wall following techniques. In this paper, it is proposed to enhance stability and efficiency using the 3 ultrasonic sensors arranged at a same perpendicular pivot. Using this method, the angle between the motorized wheelchair and the wall is detected and the range of control commands has been increased. For the better stability, the calculated slope of a wall using LSLF algorithm was fed back to the control part. By adapting the suggested algorithm and method, the motorized wheelchair could follow a wall in 4 seconds, for a change of distance between the wheelchair and wall from 30 to 100cm.