• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2004년도 춘계학술대회 학술발표 논문집 제14권 제1호
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• pp.559-562
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• 2004

In this paper, a new dual-rate digital control technique for the Takagi-Sugeno (T-S) fuzzy system is suggested. The proposed method takes account of the stabilizablity of the discrete-time T-S fuzzy system at the fast-rate sampling points. Our main idea is to utilize the lifted control input. The proposed approach is to obtain the dual-rate discrete-time T-S fuzzy system by discretizing the overall dynamics of the T-S fuzzy system with the lifted control, and then to derive the sufficient conditions for the stabilization in the sense of the Lyapunov asymptotic stability for this system.

• 한국정밀공학회지
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• 제24권2호
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• pp.86-94
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• 2007

In this paper, a dual stage servo mechanism has been developed for image tracking system to improve control performances such as small rise time, small overshoot, small settling time, small stabilization error etc. A secondary stage, a platform, actuated by a pair of electro-magnets is mounted on a conventional elevation gimbal. In this mechanism, the gimbal provides large range but slow motion and the platform provides small range but fast positioning. A sliding mode control is applied to the platform positioning to attain robust performances and stability in the presence of the disturbance related to dynamic coupling of the gimbal and the platform. Results from experiments illustrate that the suggested dual stage mechanism controlled by the sliding mode control is effective in improving responses and attenuating the disturbance response related with dynamic coupling.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.61-66
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• 1992

In this paper, a method for implementing software for the control system with dual structure in processor module is proposed and implemented to enhance its reliability. In this implementation the multi-tasking function which is provided by a real-time operating system is applied. The overall softwre is divided into five tasks and is performed in each of the dual processor module, independently. By this, the processor module with dual structure can achieve a control objective and fault diagnostics effectively. An experimental result shows that the backup processor module can be substituted for the primary processor module immediately when it happens to fail, because data relating the failure information are exchanged continuously done via shared memories.

• Journal of Power Electronics
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• 제7권2호
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• pp.118-123
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• 2007

This paper presents a new ZCS-PWM high frequency inverter. Zero current switching operation is achieved in the whole load range by using a simple auxiliary reverse blocking switch in parallel with series resonant capacitor. Dual duty cycle control scheme is used to provide a wide range of high frequency AC output power regulation that is important in many high frequency inverter applications. It found that a complete soft switching operation can be achieved even for low power setting ranges by introducing high-frequency dual duty cycle control scheme. The proposed high frequency inverter is more suitable for consumer induction heating(IH) applications. The operation and control principle of the proposed high frequency inverter are described and verified through simulated results.

• 대한통합의학회지
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• 제11권1호
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• pp.21-29
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• 2023

Purpose : Using a smartphone while walking districts attention and increases the risk of losing balance or falling. Ankle instability is caused by decreased muscle strength and decreased neuromuscular ability leading to postural control problems. Dual tasks increases the risk of falls by reducing postural control in adults with ankle instability. This study aimed to investigate the effect of performing a dual task on balance and muscle activity in adults with ankle instability using a smartphone. Methods : Forty-nine individuals with ankle instability participated in this study. A game of finding the wrong picture was performed using a smartphone in the dual task, and only looking at the blank screen of a smartphone was evaluated in the single task. The participants randomly performed single and dual task to evalutate balance and muscle atcitivy. Balance was evaluated using the Biodex balance system (BBS), and muscle activity was evaluated using surface EMG. Muscle activity of the gastrocnemius and tibialis anterior was measured at the same time as balance. Results : The results of this study showed that overall, anteior/posterior, and medial/lateral balance indices all showed significant differences when performing the dual task compared with those during the single task (p<.05). The muscle activity results showed a significant difference compared with that of the gastronemius muscle on the nondominant side during the dual task (p>.05). Conclusion : The results of this study showed that maintaining balance is more difficult when performing the dual task than during the single task, and only the muscle activity of the nondominant gastrocnemius muscle decreased. The dual task causes a decrease in concentration for postural control, which negatively affects postural stability. Individuals with ankle ankle instability should refrain from performing dual tasks, such as using smartphones, to prevent ankle damage.

• 드라이브 ㆍ 컨트롤
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• 제17권4호
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• pp.31-37
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• 2020

We are concerned with the dual-arm manipulation for disaster-responding special-purpose machinery. This paper presents a control strategy for performing complex work in an irregular environment, the control algorithm, the hydraulic circuit, and the master devices. The occurrence of collapse accidents at disaster sites such as natural disasters and building collapses is increasing, which is emerging as a social problem. In particular, for the initial response, various tasks must be performed in an irregular environment. The Marionette algorithm for intuitive control of 'as if the operator's arm is moving' was presented as a control strategy for dual-arm manipulators with attachments and the prototype. Next, the hydraulic circuit, control system, and wearable-type master device presented to implement the Marionette algorithm were explained and verified through an experiment in which rebar-cutting, drum-lifting, and lifting a bottle with one arm and pouring the water into the bucket with the other arm were tested.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2540-2545
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• 2003

We propose a new technique to the design and real-time implementation of an adaptive controller for robotic manipulator based on digital signal processors in this paper. The Texas Instruments DSPs(TMS320C80) chips are used in implementing real-time adaptive control algorithms to provide enhanced motion control performance for dual-arm robotic manipulators. In the proposed scheme, adaptation laws are derived from model reference adaptive control principle based on the improved direct Lyapunov method. The proposed adaptive controller consists of an adaptive feed-forward and feedback controller and time-varying auxiliary controller elements. The proposed control scheme is simple in structure, fast in computation, and suitable for real-time control. Moreover, this scheme does not require any accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the proposed adaptive controller is illustrated by simulation and experimental results for a dual arm robot consisting of two 4-d.o.f. robots at the joint space and cartesian space.

• Journal of international Conference on Electrical Machines and Systems
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• 제3권4호
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• pp.374-378
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• 2014

PID control method usually has problems of overshoot and oscillation in high order control system, therefore, it is important to improve the control method so as to reduce the overshoot and oscillation. Based on MATLAB simulation, a permanent magnet (PM) DC servomotor control system is studied in this paper. The motor is modeled according to the universal motor theory, and with the help of the fourth order Ronge-Kutta method, its speed control is simulated and compared between two different dual closed-loops PWM control methods. This case study helps undergraduate students to better understand theories related to electrical engineering, such as electrical machinery, power electronics and control theory, as well as digital solution of state equations.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1998년도 제13차 학술회의논문집
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• pp.244-249
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• 1998

In this paper, the hybrid state space self-tuning control technique Is studied within the framework of fuzzy systems and dual-rate sampling control theory. We show that fuzzy modeling techniques can be used to formulate chaotic dynamical systems. Then, we develop the hybrid state space self-tuning fuzzy control techniques with dual-rate sampling for digital control of chaotic systems. An equivalent fast-rate discrete-time state-space model of the continuous-time system is constructed by using fuzzy inference systems. To obtain the continuous-time optimal state feedback gains, the constructed discrete-time fuzzy system is converted into a continuous-time system. The developed optimal continuous-time control law is then convened into an equivalent slow-rate digital control law using the proposed digital redesign method. The proposed technique enables us to systematically and effective]y carry out framework for modeling and control of chaotic systems. The proposed method has been successfully applied for controlling the chaotic trajectories of Chua's circuit.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.741-746
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• 2004

We propose a new technique to the design and real-time implementation of an adaptive controller for robotic manipulator based on digital signal processors in this paper. The Texas Instruments DSPs(TMS320C80) chips are used in implementing real-time adaptive control algorithms to provide enhanced motion control performance for dual-arm robotic manipulators. In the proposed scheme, adaptation laws are derived from model reference adaptive control principle based on the improved direct Lyapunov method. The proposed adaptive controller consists of an adaptive feed-forward and feedback controller and time-varying auxiliary controller elements. The proposed control scheme is simple in structure, fast in computation, and suitable for real-time control. Moreover, this scheme does not require any accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the proposed adaptive controller is illustrated by simulation and experimental results for a dual arm robot consisting of two 4-d.o.f. robots at the joint space and cartesian space.