Active Parametric Damping of Distributed Parameter Beam Transverse Vibration

1991 ◽  
Vol 113 (2) ◽  
pp. 295-299 ◽  
Author(s):  
M. S. Habib ◽  
C. J. Radcliffe
Keyword(s):  
Closed Loop ◽  
Active Vibration Control ◽  
Distributed Parameter ◽  
Total System ◽  
Closed Loop System ◽  
Initial Value ◽  
Euler Beam ◽  
Mode Vibration ◽  
Active Vibration ◽  
Beam Transverse Vibration

An active vibration control for a modified, nonlinear, dynamic, simply supported, Bernoulli-Euler beam is introduced using one of the distributed, time-dependent parameters of the system. The control is carried out by observing the axial velocity of the end point of the beam and applying a modified bang-bang variation of beam tensile stress to control beam transverse stiffness. Numerical simulation of the closed-loop system of partial differential equations demonstrates the effectiveness of the control. Two cases representing initial value problems are given as examples. This active control applied to first mode vibration of an undamped system model yields an asymptotically stable system which loses its total system energy to a level that is 0.26 percent of its initial value in five and one half cycles.

scholarly journals Active Vibration Control of PID Based on Receptance Method

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Lijuan Peng ◽  
Jian Wang ◽  
Guicheng Yu ◽  
Zuoxue Wang ◽  
Aijun Yin ◽  
...  
Keyword(s):  
Vibration Control ◽  
Closed Loop ◽  
Damping Ratio ◽  
Active Vibration Control ◽  
Loop System ◽  
Closed Loop System ◽  
Integral Control ◽  
Active Vibration ◽  
Receptance Method ◽  
Poles And Zeros

Active vibration control approaches have been widely applied on improving reliability of robotic systems. For linear vibratory systems, the vibration features can be altered by modifying poles and zeros. To realize the arbitrary assignment of the closed-loop system poles and zeros of a linear vibratory system, in this paper, an active PID input feedback vibration control method is proposed based on the receptance method. The establishment and verification of the proposed method are demonstrated. The assignable poles during feedback control are calculated and attached with importance to expand the application of the integral control. Numerical simulations are conducted to verify the validity of the proposed method in terms of the assignment of closed-loop poles, zeros, and both. The results indicate that the proposed method can be used to realize the active vibration control of closed-loop system and obtain the desired damping ratio, modal frequency, and dynamic response.

Boundary Control of an Axially Moving String Via Lyapunov Method

1999 ◽  
Vol 121 (1) ◽  
pp. 105-110 ◽  
Author(s):  
Rong-Fong Fung ◽  
Chun-Chang Tseng
Keyword(s):  
Boundary Control ◽  
Lyapunov Method ◽  
Sliding Mode ◽  
Semigroup Theory ◽  
Active Vibration Control ◽  
Nonlinear Partial Differential Equation ◽  
Distributed Parameter ◽  
Axially Moving String ◽  
Active Vibration ◽  
Axially Moving

This paper presents the active vibration control of an axially moving string system through a mass-damper-spring (MDS) controller at its right-hand side (RHS) boundary. A nonlinear partial differential equation (PDE) describes a distributed parameter system (DPS) and directly selected as the object to be controlled. A new boundary control law is designed by sliding mode associated with Lyapunov method. It is shown that the boundary feedback states only include the displacement, velocity, and slope of the string at RHS boundary. Asymptotical stability of the control system is proved by the semigroup theory. Finally, finite difference scheme is used to validate the theoretical results.

scholarly journals High Speed, High Temperature, Fault Tolerant Operation of a Combination Magnetic-Hydrostatic Bearing Rotor Support System for Turbomachinery

2004 ◽  
Author(s):  
Mark Jansen ◽  
Gerald Montague ◽  
Andrew Provenza ◽  
Alan Palazzolo
Keyword(s):  
High Temperature ◽  
High Speed ◽  
Closed Loop ◽  
Fault Tolerant ◽  
Active Vibration Control ◽  
Control Algorithms ◽  
Displacement Sensors ◽  
Rotor Support ◽  
Active Vibration ◽  
Speed Computer

Closed loop operation of a single, high temperature magnetic radial bearing to 30,000 RPM (2.25 million DN) and 540°C (1,000°F) is discussed. Also, high temperature, fault tolerant operation for the three axis system is examined. A novel, hydrostatic backup bearing system was employed to attain high speed, high temperature, lubrication free support of the entire rotor system. The hydrostatic bearings were made of a high lubricity material and acted as journal-type backup bearings. New, high temperature displacement sensors were successfully employed to monitor shaft position throughout the entire temperature range and are described in this paper. Control of the system was accomplished through a stand alone, high speed computer controller and it was used to run both the fault-tolerant PID and active vibration control algorithms.

Tunable and Transferrable Bar Feeder Damping Design for Advanced Manufacturing

2013 ◽  
Author(s):  
Harry A. Pierson ◽  
Kumer V. Singh
Keyword(s):  
Vibration Suppression ◽  
Control Strategies ◽  
Active Vibration Control ◽  
Viscoelastic Model ◽  
Advanced Manufacturing ◽  
Euler Beam ◽  
Batch Sizes ◽  
Active Vibration ◽  
Cnc Turning Centers ◽  
High Degree

The economical production of high-value, low-volume, machined components is an important subtopic of advanced manufacturing. Bar feeders, a well-established technology for adding a high degree of automation to CNC turning centers by feeding 12′ lengths of stock through the machine spindle, have limitations in this realm. They rely on supporting the entire length of the stock in a continuous fluid bearing in order to suppress potential vibrations. Although this results in excellent vibration suppression, long tooling changeovers make them impractical for small batch sizes. Additionally, the expense of the tooling can render them cost-prohibitive. Thus a bar feeder technology is desired that provides comparable vibration suppression for a wide variety of stock sizes without the need for size-specific tooling changes. In this, a movable point support having tunable viscoelastic properties is studied for controlling the vibration of varying lengths of bar stock in a given speed range. The transverse vibration of mounted bar stock is modeled as a Bernoulli-Euler beam. The effects of the support position, viscoelastic model, and their associated parameters on the resonant frequencies, damping ratios, and vibration response of the bar stock are studied. Such a study will be instrumental in developing passive/active vibration control strategies for future bar feeders.

Active Vibration Control of Rotating Machinery With a Hybrid Piezohydraulic Actuator System

1995 ◽  
Vol 117 (4) ◽  
pp. 767-776 ◽  
Author(s):  
P. Tang ◽  
A. B. Palazzolo ◽  
A. F. Kascak ◽  
G. T. Montague
Keyword(s):  
Vibration Control ◽  
Closed Loop ◽  
Active Vibration Control ◽  
Aircraft Engines ◽  
Test Results ◽  
State Space Methods ◽  
Low Viscosity ◽  
Actuator System ◽  
Active Vibration ◽  
Hybrid Actuator

An integrated, compact piezohydraulic actuator system for active vibration control was designed and developed with a primary application for gas turbine aircraft engines. Copper tube was chosen as the transmission line material for ease of assembly. Liquid plastic, which meets incompressibility and low-viscosity requirements, was adjusted to provide optimal actuator performance. Variants of the liquid plastic have been prepared with desired properties between −40°F and 400°F. The effectiveness of this hybrid actuator for active vibration control (AVC) was demonstrated for suppressing critical speed vibration through two critical speeds for various levels of intentionally placed imbalance. A high-accuracy closed-loop simulation, which combines both finite element and state space methods, was applied for the closed-loop unbalance response simulation with/without AVC. Good correlation between the simulation and test results was achieved.

Active Vibration Control of Storage and Retrieval Machines

2008 ◽  
Author(s):  
Daniel Go¨rges ◽  
Jens Kroneis ◽  
Steven Liu
Keyword(s):  
Feedback Control ◽  
Vibration Control ◽  
Trajectory Planning ◽  
Active Vibration Control ◽  
Beam Theory ◽  
State Feedback Control ◽  
Dimensional Model ◽  
Euler Beam ◽  
Storage And Retrieval ◽  
Active Vibration

In this paper a novel concept for active vibration control of storage and retrieval machines is presented. The storage and retrieval machine is modeled based on the Bernoulli-Euler beam theory, yielding an infinite-dimensional model, and the assumed modes method in order to obtain a finite-dimensional model. The resulting model is of low order, a fourth-order model regarding the first and the second eigenfrequency describes the dynamics sufficiently. The model is verified on an experimental storage and retrieval machine. Several active vibration control strategies are studied, including trajectory planning approaches like higher-order trajectory planning, feedforward control approaches like trajectory filtering and input shaping, and feedback control approaches like state-feedback control. The strategies are evaluated by simulation and compared via performance measures.

Model Based Simulation of the Active Damping of a Cantilever Plate and Redistribution of Stresses

2000 ◽  
Author(s):  
Sathya V. Hanagud ◽  
Patrick J. Roberts
Keyword(s):  
Control System ◽  
Vibration Control ◽  
Closed Loop ◽  
Active Vibration Control ◽  
High Stress ◽  
Element Simulation ◽  
Control Scheme ◽  
Acceleration Feedback ◽  
Order Of Magnitude ◽  
Active Vibration

Abstract In most structures, fatigue critical areas are associated with regions of high stresses. Sometimes, passive stiffening of structures can displace these high stress regions. Thus, for most applications, active vibration control is preferred. However, the question of whether an active vibration control scheme involving a set of actuators will reduce stresses in the whole structure or create high stress areas in the vicinity of the actuators arises. In previous works, this question has been addressed for cantilever beams which showed that the stresses are reduced by approximately the same order of magnitude as the reduction in vibrations. However, many aerospace structures are constructed of thin walled components whose response to vibration reduction can be very different than that of beams. In this paper, the stresses induced by an active vibration control system, based on the use of an offset piezoceramic stack actuator with acceleration feedback control, are investigated in a plate structure. A 3-D finite element simulation of the closed loop active vibration control system is developed and both the closed loop stresses and vibration amplitude reductions are studied.

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