• Title/Summary/Keyword: Proportional-derivative control

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Effect of Active Control Bearing on Unbalance Response of a Rotor-Bearing System (축-베어링 계의 불균형 응답에 대한 능동 제어 베어링의 효과)

  • 노병후;김경웅
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2001.11a
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    • pp.316-321
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    • 2001
  • The paper presents the unbalance response of a rotor-bearing system supported by an active control bearing. The proportional, derivative and integral controls are employed for the control algorithm of an active control bearing to suppress the unbalance response of a rotor-bearing system. Results of analytical investigations on the unbalance responses of a rotor supported by an active control bearing are presented for various control gains. It is found that the unbalance response of a rotor can be greatly suppressed by the proportional, derivative or integral control of the bearing. The proportional control is more effective than the derivative control at low rotational speed, and the derivative control is more effective than the proportional control at high rotational speed. In the case of the integral control of the bearing , the unbalance response of a rotor is increased as a general rule. However, the integral control of the bearing is extremely superior to proportional or derivative control at very low rotational speed.

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Effect of Active Control Bearing on Unbalance Response of a Rotor-Bearing System (축-베어링 계의 불균형 응답에 대한 능동 제어 베어링의 효과)

  • 노병후;김경웅
    • Tribology and Lubricants
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    • v.18 no.2
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    • pp.99-104
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    • 2002
  • The paper presents the unbalance response of a rotor-bearing system supported by an active control bearing. The proportional, derivative and integral controls are investigated fur the control algorithm of an active control bearing to suppress the unbalance response of a rotor-bearing system. Results of analytical investigations on the unbalance responses of a rotor supported by an active control bearing are presented for various control gains. It is found that the unbalance response of a rotor can be greatly suppressed by the proportional, derivative or integral control of the bearing. The proportional control is more effective than the derivative control at low rotational speed, and the derivative control is more effective than the proportional control at high rotational speed. In the case of the integral control of the bearing, the unbalance response ova rotor is increased as a general rule. However, the integral control of the bearing is extremely superior to proportional or derivative control at very low rotational speed.

A Study on Proportional and Derivative Control of Fluid Film Journal Bearings (유체 윤활 베어링의 비례 및 미분 제어에 관한 연구)

  • 노병후;김경웅
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2001.06a
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    • pp.212-217
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    • 2001
  • This paper presents the stability characteristics of a rotor-bearing system supported by actively controlled hydrodynamic journal bearing. The proportional and derivative controls including coupled motion are adopted for the control algorithm to control the hydrodynamic journal bearing with a circumferentially groove. Also, the cavitation algorithm implementing the Jakobsson-Floberg-Olsson boundary condition is adopted to predict cavitation regions in the fluid film more accurately than conventional analysis which uses the Reynolds condition. The stability characteristics are investigated with the Routh-Hurwitz criteria using the linear dynamic coefficients which are obtained from the perturbation method. The stability characteristics of the rotor-bearing system supported by active controlled hydrodynamic journal bearing are investigated for various control gain. It is found that the speed at onset of instability is increased for both proportional and derivative control of the bearing, and the proportional and derivative control of coupled motion is more effective than proportional and derivative control of uncoupled motion.

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Proportional and Derivative Control of Hydrodynamic Journal Bearings (동압 베어링의 비례 및 미분 제어)

  • 노병후;김경웅
    • Tribology and Lubricants
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    • v.17 no.4
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    • pp.283-289
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    • 2001
  • The paper presents the stability characteristics of a rotor-bearing system supported by actively controlled hydrodynamic journal bearing. The proportional and derivative controls including coupled motion are adopted for the control algorithm to control the hydrodynamic journal bearing with a circumferentially groove. Also, the cavitation algorithm implementing the Jakobsson-Floberg-Olsson boundary condition is adopted to predict cavitation regions in the fluid film more accurately than a conventional analysis which uses the Reynolds condition. The stability characteristics of a rotor-bearing system supported by actively controlled hydrodynamic journal bearing are investigated for various control gains with the Routh-Hurwitz criteria using the linear dynamic coefficients which are obtained from the perturbation method. It is found that the speed at onset of the instability is increased for both proportional and derivative control of the bearing. It is also found that the proportional and derivative control of the coupled motion is more effective than that of the uncoupled motion.

A Study on Dynamic Characteristics of a Rotor-Bearing System Supported by Actively Controlled Fluid Film Journal Bearing (능동 제어 유체 윤활 베어링으로 지지된 축-베어링 시스템의 동특성에 관한 연구)

  • No, Byeong-Hu;Kim, Gyeong-Ung
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.8
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    • pp.116-121
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    • 2001
  • The paper presents the dynamic characteristics of a rotor-bearing system supported by an actively controlled hydrodynamic journal bearing. The proportional. derivative and integral controls are adopted for the control algorithm to control the hydrodynamic journal bearing with an axial groove. Also, the cavitation algorithm implementing the Jakobsson-Floberg-Olsson boundary condition is adopted to predict cavitation regions in the fluid film more accurately than conventional analysis, which uses the Reynolds condition. The speed at onset of instability of a rotor-bearing system is increased by both proportional and derivative control of the bearing. The proportional control increases the stability threshold without affecting the whirl ratio. However, for the derivative control of the bearing, increase of stability threshold speed is accompanied by a parallel reduction of the whirl ratio. The integral control has no effect on stability characteristics of hydrodynamic journal bearing. The PD-control is more effective than proportional or derivative control. Results 7how the active control of bearing can be adopted for the stability improvement of a rotor-bearing system.

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Auto-tuning of PID/PIDA Controllers based on Step-response (스텝응답에 기반한 PID/PIDA 제어기의 자동동조)

  • Ahn, Kyung-Pil;Lee, Jun-Sung;Lim, Jae-Sik;Lee, Young-Il
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.10
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    • pp.974-981
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    • 2009
  • In this paper, a method of auto-tuning of PID (Proportional-Integral-Derivative) and PIDA (Proportional-Integral-Derivative-Acceleration) controllers is proposed that can be applied to a time-delayed second order model. The proposed identification method is based on step responses, but it can be easily automated rising digital controller unlike the existing graphical identification methods. We provide a ways to yield parameter identifications which is independent to initial values of the plants. The tuning rule is based on the pole-placement strategy and is formulated so that it can be implemented using a digital controller with ease.

A Study on the Stability Characteristics of Actively Controlled Externally Pressurized Air Journal Bearing (능동 제어되는 외부 가압 공기 베어링의 안정 특성에 관한 연구)

  • Lee, Jeong-Bae;Kim, Gyeong-Ung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.3 s.174
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    • pp.543-549
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    • 2000
  • Results of theoretical investigations of the stability characteristics of an actively controlled externally pressurized air journal bearing are presented. Proportional control and derivative control are used for the control algorithm of active air bearing. The stability characteristics of the actively controlled bearing operating at zero steady-state eccentricity is investigated with the step jump method. The speed at onset of instability is raised for both proportional control and derivative control of bearing. Proportional control increased the stability threshold without affecting the whirl ratio. But for derivative control of bearing, stability threshold increase is accompanied by a parallel reduction of the whirl ratio. Results show active control of bearing can be adopted for the stability improvement of air journal bearing.

A Study on Dynamic Characteristics of a Rotor-Bearing System Supported by Actively Controlled Hydrodynamic Journal Bearing (능동 제어 베어링으로 지지된 축-베어링 시스템의 동특성에 관한 연구)

  • 노병후;김경웅
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.635-638
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    • 2001
  • This paper presents the dynamic characteristics of r rotor-bearing system supported by an actively controlled hydrodynamic journal bearing. The proportional, derivative and integral controls are adopted for the control algorithm to control the hydrodynamic journal bearing with an axially groove. Also, the cavitation algorithm implementing the Jakobsson-Floberg-olsson boundery condition is adopted to predict cavitation regions in the fluid film more accurately than conventional analysis, which uses the Reynolds condition. The speed at onset of instability of a rotor-bearing system is increased by both proportional and derivative control of the bearing. The integral control has no effect on stability characteristics of hydrodynamic journal bearing. The PD-control is more effective than proportional or derivative control. Results show the active control of bearing can be adopted for the stability improvement of a rotor-bearing system.

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Output Feedback Passivation of Non-square Linear Systems Using an Input-Dimensional Compensator (입력 차수 보상기를 이용한 비정방 선형 시스템의 출력 궤환 수동화)

  • 손영익
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.53 no.1
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    • pp.10-15
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    • 2004
  • We present a state-space approach to make non-square linear systems strictly passive by using an input-dimensional parallel feedforward compensator. A necessary and sufficient condition for the existence of the parallel feedforward compensator is given by the static output feedback formulation, which enables to utilize linear matrix inequality. By modifying the structure of the compensator the additional technical assumption in the previous result [1] is removed. The effectiveness of the proposed method is illustrated by some numerical examples which can be stabilized by the proportional-derivative (PD) and proportional-derivative-integral (PID) control laws. The proposed control scheme can successfully replace the measurements of derivative terms in the control laws.

Control of the pressurized water nuclear reactors power using optimized proportional-integral-derivative controller with particle swarm optimization algorithm

  • Mousakazemi, Seyed Mohammad Hossein;Ayoobian, Navid;Ansarifar, Gholam Reza
    • Nuclear Engineering and Technology
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    • v.50 no.6
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    • pp.877-885
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    • 2018
  • Various controllers such as proportional-integral-derivative (PID) controllers have been designed and optimized for load-following issues in nuclear reactors. To achieve high performance, gain tuning is of great importance in PID controllers. In this work, gains of a PID controller are optimized for power-level control of a typical pressurized water reactor using particle swarm optimization (PSO) algorithm. The point kinetic is used as a reactor power model. In PSO, the objective (cost) function defined by decision variables including overshoot, settling time, and stabilization time (stability condition) must be minimized (optimized). Stability condition is guaranteed by Lyapunov synthesis. The simulation results demonstrated good stability and high performance of the closed-loop PSO-PID controller to response power demand.