• 한국소음진동공학회논문집
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• 제14권7호
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• pp.619-625
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• 2004

Direct velocity feedback (DVFB) control is known that it offers an unconditional stability with very high performance when the control strategy is applied at a point collocated sensor and actuator pair. because the sensor-actuator pair has strictly positive real (SPR) property In this paper, two types of collocated sensor-actuator pairs are considered for practical active vibration control of a structure. They are a Point collocated sensor-actuator pair and a point sensor-distributed actuator pair. Both pairs with DVFB show robust stability and performance. It is noted that the collocated point sensor-actuator ultimately acts as a “skyhook” damper, hut the point sensor-distributed actuator pair with DVFB acts as a “skyhook” rotational damper pair.

• 대한기계학회논문집A
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• 제21권12호
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• pp.2179-2186
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• 1997

In this paper, the performance of a semi-active suspension system for a passenger car has been investigated. Alternative semi-active suspensions control laws has been compared via simulations. The control laws investigated in this study are : sprung mass velocity feedback control law, sky-hook damping control law, and state feedback control law. Simulation results show that a semi-active suspension has potential to improve ride quality of automobiles.

• Smart Structures and Systems
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• 제22권1호
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• pp.95-103
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• 2018

Active vibration control via inertial mass actuators has been shown as an effective tool to significantly reduce human-induced vertical vibrations, allowing structures to satisfy vibration serviceability limits. However, a lot of practical obstacles have to be solved before experimental implementations. This has motivated simple control techniques, such as direct velocity feedback control (DVFC), which is implemented in practice by integrating the signal of an accelerometer with a band-pass filter working as a lossy integrator. This work provides practical guidelines for the tuning of DVFC considering the damping performance, inertial mass actuator limitations, such as stroke and force saturation, as well as the stability margins of the closed-loop system. Experimental results on a full scale steel-concrete composite structure (behaves similar to a footbridge) with adjustable span are reported to illustrate the main conclusions of this work.

• 한국정밀공학회지
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• 제20권12호
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• pp.89-95
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• 2003

A PID controller integrated with a velocity feedback is designed for fluid power elevator model system in this study. In this case, for outside disturbance load a hydraulic cylinder and a pressure control valve are used. In this method overshoot is reduced and settling time becomes also shorter than the values achieved from the PID controller system only In conclusion a PID controller integrated with a velocity feedback is considered a suitable control method for fluid power elevator system.

• 한국소음진동공학회논문집
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• 제14권10호
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• pp.1007-1014
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• 2004

This paper presents a study of low frequencies volume velocity vibration control of a smart panel in order to reduce sound transmission. A distributed piezoelectric quadratically shaped polyvinylidene fluoride (PVDF) polymer film is used as a uniform force actuator and an array of $4\;{\times}\;4$ accelerometer is used as a volume velocity sensor for the implementation of a single-input single-output control system. The theoretical and experimental study of sensor-.actuator frequency response function shows that this sensor-actuator arrangement provides a required strictly positive real frequency response function below about 900 Hz. Direct velocity feedback could therefore be implemented with a limited gain which gives reductions of about 15 dB in vibration level and about 8 dB in acoustic power level at the (1,1) mode of the smart panel. It has been also shown that the shaping error of PVDF actuator could limit the stability and performance of the control system.

• International Journal of Control, Automation, and Systems
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• 제2권4호
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• pp.435-449
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• 2004

In this paper, a novel anti-sway control system that uses an inclinometer as a sway sensor is investigated. The inclinometer, when compared with a vision system, is very cheap, durable, and easy to maintain, while providing almost the same performance. A number of observers to estimate the angular velocity of the load and the trolley velocity are presented. A state feedback controller with an integrator is designed. After a time-scale analysis, a 1/4-size pilot crane of a rail-mounted quayside crane was constructed. The performance of the proposed control system was verified with a real rubber-tired gantry crane at a container terminal as well as with the constructed pilot crane. Experimental results are provided.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1998년도 추계학술대회논문집:21세기에 대비한 지능형 통합항만관리
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• pp.159-165
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• 1998

In this paper the sway-control problem of a container crane is investigated. The control loop is divided into two stages. The first stage is a modified time optimal control for trolley traversing. The velocity command for trolley traversing consists of three components ; a reference velocity and two feedback signals for compensating the deviations of trolley and sway angle from their desired trajectories. For trolley's exact positioning the trolley dynamics is identified via an error equation identifier structure. The second stage is a nonlinear residual sway control that starts at the end of first stage. The control design for the second stage is investigated from the perspective of controling an underactuated system, and the control law combines the feedback linearization and variable structure control.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.101-106
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• 1998

This paper deals with the difference of the static and kinetic thrust characteristics of a linear pulse motor(LPM) without and with feedback control for a total artificial heart(TAH). In general, the kinetic thrust of LPM without feedback control decreases as increasing the mover velocity. The kinetic thrust characteristics of the LPM with feedback control are improved approximately 30% as compared with the LPM without feedback control in the high velocity range.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
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• pp.247-250
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• 2003

In this paper, we propose a robust controller for motion control of n-link robot manipulators using visual feedback. The desired joint velocity and acceleration is obtained by the feature-based visual systems and is used in the joint velocity control loop for trajectory control of the robot manipulator. We design a robust controller that compensates for bounded parametric uncertainties of robot dynamics. The stability analysis of robust joint velocity control system is shown by Lyapunov Method. The effectiveness of the proposed method is shown by simulation results on the 5-link robot manipulators with two degree of freedom.

• Earthquakes and Structures
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• 제6권2호
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• pp.217-235
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• 2014

In this paper, different feedback control strategies are presented for active seismic control using proportional-integral-derivative (PID) type controllers. The parameters of PID controller are found by using an numerical algorithm considering time delay, maximum allowed control force and time domain analyses of shear buildings under different earthquake excitations. The numerical algorithm scans combinations of different controller parameters such as proportional gain ($K_p$), integral time ($T_i$) and derivative time ($T_d$) in order to minimize a defined response of the structure. The controllers for displacement, velocity and acceleration feedback control strategies are tuned for structures with active control at the first story and all stories. The performance and robustness of different feedback controls on time and frequency responses of structures are evaluated. All feedback controls are generally robust for the changing properties of the structure, but acceleration feedback control is the best one for efficiency and stability of control system.