• Journal of Industrial Technology
• /
• v.22 no.B
• /
• pp.185-190
• /
• 2002

This paper describes a design of an induction motor control system using a 2 degree-of-freedom PI controller to compensate the effects of disturbance without degrading tracking performance. On the basis of vector control principle, the control system is simulated by using the ACSL and implemented on a DSP system(TMS320C31). In designing the 2 DOF controller, we can tune the performance of either the tracking or disturbance rejection independently without affecting the other. With the experimental results, the 2 DOF controller has shown a better performance in command tracking and disturbance rejection than a conventional PI controller.

• 제어로봇시스템학회:학술대회논문집
• /
• 1991.10a
• /
• pp.1-6
• /
• 1991

This paper is concerned with the design of a robust tracking controller using a state observer on a robotic manipulator under the disturbance. The controller is designed to follow a step or ramp reference input without steady state error in the presence of a disturbance and a system parameter variation. In most cases, since all the state vectors are not measured, unmeasurable state vectors must be estimated or reconstructed. A reduced order observer is proposed to estimate unmeasurable state vectors of the non-linear system. Some problems are caused by the Coulomb friction, the disturbance, and the spring effect of a link between the drive motor and the manipulator arm. The state variables, directly measured and estimated by the reduced order observer, are fed back to the controller. When the robot system exhibits the 'limit cycle, the feedback gains initially obtained by optimal control theory are changed. As a result, the limit cycle is eliminated by the new controller gains,

• 제어로봇시스템학회:학술대회논문집
• /
• 1992.10a
• /
• pp.86-89
• /
• 1992

One of the most difficult problems in depth control for underwater vehicle is the effect of seaway disturbance. One component of the seaway forces is of large magnitude with a relatively narrow-band, first order component. The other component is generaly of somewhat smaller magnitude, second order component. Since the magnitude of the first order component is generally much greater than the compensating force that can be generating by the planes, it is undesirable for the controller to generate a control command. In this paper, we disigned adaptive notch filtering system using filter bank structure. Energies of each band-passed signal are obtained by MA(Moving Average) method and compared to produce center frequency. By adapting this parameter to notch filter, 1st order seaway disturbance can be removed, which lead to the improvement of automatic depth control system.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.58 no.1
• /
• pp.160-167
• /
• 2009

In this paper, we apply the robust disturbance observer (DOB) to a SPM-based data storage (SDS) system. In the SDS system, coupling dynamics and parameter uncertainties are obstacles to the precision tracking control. Although the DOB is known to be an effective method to reject disturbances, there has been no systematic design approach to how to design DOB parameters. In this paper, the robust DOB is formulated based on the robust stabilization of normalized coprime factor plant description and the $H{\infty}$ loop shaping method. From the simulation and experimental results. the improved robustness and performance are obtained by the proposed robust DOB.

• Journal of Drive and Control
• /
• v.10 no.3
• /
• pp.14-20
• /
• 2013

In the study, a control strategy using a feedback linearization compensator and a disturbance observer was suggested and applied to the synchronization control of two hydraulic cylinders. The hydraulic system consists of a proportional directional control valve with overlap characteristic near the neutral position, a conventional hydraulic cylinder and an external load. The control performances of the system were verified through numerical simulations. From the simulations, it was ascertained that excellent control performances were obtained with the suggested control strategy.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.17 no.10
• /
• pp.912-917
• /
• 2007

Recently, dynamic system has been enlarged and is normally exposed to various types of disturbance. Thus designing controller for these dynamic systems under random disturbance is not practically easy. As a result, the exact analysis for the system which is exposed to various irregular disturbance is quite important. In order to perform analysis, conventional BMR(balance model reduction) method is adopted and applied to moment equation in stochastic domain. Reliable reduced order system model has been obtained.

• Journal of Power System Engineering
• /
• v.12 no.1
• /
• pp.72-79
• /
• 2008

This paper designs a looper-tension controller for mass-flow stabilization in hot strip finishing mills. By Newton's 2nd law and Hooke's law, nonlinear dynamic equations on the looper-tension system are firstly derived, and linearized by a linearization algorithm using a Taylor's series expansion. Moreover, a tension calculation model is obtained from the nonlinear dynamic equations which is called as a soft sensor of strip tension between two neighboring stands. Next, a looper-tension servo controller is designed by an ILQ(Inverse Linear Quadratic optimal control) algorithm, and it is combined with a minimal disturbance observer which to attenuate speed disturbances by AGC and operator interventions, etc.. Finally, it is shown from by a computer simulation that the proposed ILQ controller with a disturbance observer is very effective in stabilizing the strip mass-flow under some disturbances, moreover it has a good command following performance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2003.05a
• /
• pp.1058-1062
• /
• 2003

This paper proposes a self-organizing fuzzy controller (SOFC) design technique applied to the vibration control of a dynamic system under irregular disturbance. In this controller, the fuzzy rules generate control signal continuously using the array of input and output pairs without using any special controller model. The generated rules are saved in the fuzzy rule matrix in real-time by self-organizing methods. This fuzzy logic control is demonstrated by simulation and shows the efficiency of the real-time self-organizing fuzzy controller in this system.

• Journal of Institute of Control, Robotics and Systems
• /
• v.7 no.7
• /
• pp.605-613
• /
• 2001

In this paper, we design a robust adaptive controller for a nonlinear system with uncertainties to be rejected via disturbance adaptation law. The nonlinear system considered has unknown nonlinear functions being influenced by external disturbance. The upper bound of unknown nonlinear functions at each time is estimated by using a disturbance adaptation law. The estimated nonlinear functions are used to design a stabilizing function a control input. Tuning function is used to estimates unknown system parameter without overparametrization. A set-point regulation error converges to a residual set close to zero asymptotically. The effectiveness of the proposed controller is investigated by computer simulation.

• Proceedings of the KSR Conference
• /
• 2006.11b
• /
• pp.1430-1435
• /
• 2006

This study deals with the problem of balance beam system to stabilize about static and sinusoidal disturbance. wherein the design objectives are to keep the gap deviation from static and sinusoidal disturbance. In this paper propose the 2-Degree of Freedom(DOF) structure and a simple first-order controller which is designed by Characteristic ratio assignment (CRA) method. Matlab simulation result verify stabilization of balance beam system despite of disturbance. Hybrid simulation between digital controller and analog plant is presented by Matlab Simulink.