scholarly journals Active Control of Dynamic Bearing Loads in Rotating Machinery Using the Deflection Coefficient Method for Load Estimation

1997 ◽  
Vol 2 (4) ◽  
Author(s):  
William W. Clark ◽  
Joo-Hyung Kim ◽  
Roy D. Marangoni
Keyword(s):  
Active Control ◽  
Rotating Machinery ◽  
Load Estimation ◽  
Deflection Coefficient ◽  
Bearing Loads ◽  
Coefficient Method

scholarly journals Active Control of Dynamic Bearing Loads in Rotating Machinery Using Non-Invasive Measurements

1994 ◽  
Author(s):  
William W. Clark ◽  
Joo-Hyung Kim ◽  
Roy D. Marangoni
Keyword(s):  
Rotating Machinery ◽  
Non Invasive ◽  
Deflection Coefficient ◽  
Bearing Load ◽  
Shaft Deflection ◽  
Reaction Forces ◽  
Bearing Loads ◽  
A New Technique ◽  
Adaptive Feedforward ◽  
Coefficient Method

A new technique for measuring and actively controlling dynamic bearing loads in rotating machinery is presented. Bearing loads are estimated using the Deflection-Coefficient Method, a technique which does not rely on a full system model, and which applies commonly-used shaft-deflection measurement equipment to obtain estimates of bearing loads. The estimated bearing load is used as an error signal in an adaptive feedforward disturbance rejection controller. The result is a control system which can selectively minimize dynamic bearing loads in real time in rotating machinery systems. The method is applied to a numerical model of a typical rotating machinery system to suppress dynamic reaction forces at bearing supports.

PI Control of HSFDs for Active Control of Rotor-Bearing Systems

1997 ◽  
Vol 119 (3) ◽  
pp. 658-667 ◽  
Author(s):  
J. P. Hathout ◽  
A. El-Shafei
Keyword(s):  
Vibration Control ◽  
Active Control ◽  
Closed Loop ◽  
Rotating Machinery ◽  
Loop System ◽  
Pi Control ◽  
Closed Loop System ◽  
Transient Vibration ◽  
Critical Speeds ◽  
Rotor Bearing

This paper describes the proportional integral (PI) control of hybrid squeeze film dampers (HSFDS) for active control of rotor vibrations. Recently it was shown that the automatically controlled HSFD based on feedback of rotor speed can be a very efficient device for active control of rotor vibration when passing through critical speeds. Although considerable effort has been put into the study of steady-state vibration control, there are few methods in the literature applicable to transient vibration control of rotor-bearing systems. Rotating machinery may experience dangerously high dynamic loading due to the sudden mass unbalance that could be associated with blade loss. Transient run-up and coast down through critical speeds when starting up or shutting down rotating machinery induces excessive bearing loads at criticals. In this paper, PI control is proposed as a regulator for the HSFD system to attenuate transient vibration for both sudden unbalance and transient runup through critical speeds. A complete mathematical model of this closed-loop system is simulated on a digital computer. Results show an overall enhanced behavior for the closed-loop rotor system. Gain scheduling of both the integral gain and the reference input is incorporated into the closed-loop system with the PI regulator and results in an enhanced behavior of the controlled system.

Active Control Algorithms for the Control of Rotor Vibrations Using HSFDs

2000 ◽  
Author(s):  
A. El-Shafei
Keyword(s):  
Active Control ◽  
Gain Scheduling ◽  
Rotating Machinery ◽  
Squeeze Film ◽  
Control Algorithms ◽  
Critical Stage ◽  
Squeeze Film Damper ◽  
Active Vibration

The Hybrid Squeeze Film Damper (HSFD) has proven itself to be an effective controlling device of vibration in rotating machinery. The critical stage in the development of the HSFD as an active vibration suppressant, is the development of the control algorithms for active control of rotor vibrations. This paper summarizes, evaluates and compares the control algorithms for HSFD supported rotors. Quantitative as well as qualitative measures of the effectiveness of the control algorithms are presented. The study includes the PID-type controllers, LQR, gain scheduling, adaptive and bang-bang controllers. The adaptive, gain scheduling and nonlinear proportional controllers, have proved to be quite effective in the active control of HSFD supported rotors, with impressive results.

scholarly journals PI Control of HSFDs for Active Control of Rotor-Bearing Systems

1996 ◽  
Author(s):  
J. P. Hathout ◽  
A. El-Shafei
Keyword(s):  
Vibration Control ◽  
Active Control ◽  
Closed Loop ◽  
Rotating Machinery ◽  
Loop System ◽  
Pi Control ◽  
Closed Loop System ◽  
Transient Vibration ◽  
Critical Speeds ◽  
Run Up

This paper describes the proportional integral (PI) control of hybrid squeeze film dampers (HSFDs) for active control of vibrations of rotors. Recently it was shown that the automatically controlled HSFD based on feedback of rotor speed can be a very efficient device for active control of rotor vibration when passing through critical speeds. Although considerable effort has been put into the study of steady state vibration control, there are few methods in the literature applicable to transient vibration control of rotor-bearing systems. Rotating machinery may experience dangerously high dynamic loading due to the sudden mass unbalance that could be associated with blade loss. Transient run-up and coast down through critical speeds when starting up or shutting down rotating machinery induces excessive bearing loads at criticals. In this paper, PI control is proposed as a regulator for the HSFD system to attenuate transient vibration for both sudden unbalance and transient run-up through critical speeds. A complete mathematical model of this closed-loop system is simulated on a digital computer. Results show an overall enhanced behavior for the closed-loop rotor system. Gain scheduling of both the integral gain and the reference input is incorporated to the closed-loop system with the PI regulator and results in an enhanced behavior of the controlled system.

scholarly journals Design of a Hydraulic Actuator for Active Control of Rotating Machinery

1991 ◽  
Author(s):  
Majid Rashidi ◽  
Eliseo Dirusso
Keyword(s):  
Active Control ◽  
Optimum Design ◽  
Elastic Plate ◽  
Electromagnetic Force ◽  
Characteristic Number ◽  
Rotating Machinery ◽  
Thin Elastic Plate ◽  
Hydraulic Actuator ◽  
Nominal Pressure ◽  
Hydraulic Servo

A Hydraulic actuator was designed and is described herein. This actuator consists of: a pump which generates the nominal pressure, a hydraulic servo-valve, and a thin elastic plate which transduces the generated pressure variations into forces acting on a mass which simulates the bearing of a rotor system. An actuator characteristic number is defined to provide a base for an optimum design of force actuators with combined weight, frequency, and force considerations. This characteristic number may also be used to compare hydraulic and electromagnetic force actuators. In tests this actuator generated 182.3 Newton force at a frequency of 100. Hz. and a displacement amplitude of 5.8×10−5 meter.

Design of a Hydraulic Actuator for Active Control of Rotating Machinery

1993 ◽  
Vol 115 (2) ◽  
pp. 336-340 ◽  
Author(s):  
M. Rashidi ◽  
E. Dirusso
Keyword(s):  
Active Control ◽  
Optimum Design ◽  
Elastic Plate ◽  
Electromagnetic Force ◽  
Characteristic Number ◽  
Rotating Machinery ◽  
Rotor System ◽  
Thin Elastic Plate ◽  
Hydraulic Actuator ◽  
Nominal Pressure

A hydraulic actuator was designed and is described herein. This actuator consists of: a pump, which generates the nominal pressure, a hydraulic servovalve, and a thin elastic plate, which transduces the generated pressure variations into forces acting on a mass, which simulates the bearing of a rotor system. An actuator characteristic number is defined to provide a base for an optimum design of force actuators with combined weight, frequency, and force considerations. This characteristic number may also be used to compare hydraulic and electromagnetic force actuators. In tests this actuator generated 182.3 N force at a frequency of 100. Hz. and a displacement amplitude of 5.8×10−5 m.

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