scholarly journals Active vibration control of a railway pantograph

1997 ◽  
Vol 211 (2) ◽  
pp. 117-130 ◽  
Author(s):  
T. X. Wu ◽  
M. J. Brennan
Keyword(s):  
Degrees Of Freedom ◽  
Control Strategies ◽  
Dynamic Performance ◽  
Active Vibration Control ◽  
Control Force ◽  
Optimal Control Strategy ◽  
Advantages And Disadvantages ◽  
Full State Feedback ◽  
Active Vibration ◽  
The Stability

Current collection for electrical trains can be improved by the use of an active pantograph. To design such a system the behaviour of both the active pantograph and the overhead catenary system must be considered together. In this paper a two degrees-of-freedom model of an active pantograph, combined with a time-varying spring representing the catenary's influence, is employed and its dynamic performance is studied. Based on this model, three types of control strategies for an active pantograph are proposed and investigated, and all these models consider the interaction of the pantograph with the overhead wire. Two possible positions for mounting an actuator on the pantograph are considered and compared. From these active pantograph models the magnitude of the control force required can be estimated, and the advantages and disadvantages are discussed. The optimal control strategy shows the best performance, but introduces measurement difficulties because it needs full-state feedback. Classical feedback control is the least difficult to implement, but a compromise between the stability and the performance should be reached.

Vibration Reduction in Large Flexible Systems Through Independent Modal Control

2011 ◽  
Author(s):  
Francesco Braghin ◽  
Simone Cinquemani ◽  
Ferruccio Resta
Keyword(s):  
Acoustic Noise ◽  
Dynamic Performance ◽  
Active Vibration Control ◽  
Spillover Effects ◽  
Flexible System ◽  
Damping Matrix ◽  
Modal Damping ◽  
Active Vibration ◽  
The Stability ◽  
Modal Controller

Many systems have, by their nature, a small damping and therefore they are potentially subjected to dangerous vibration phenomena. The aim of active vibration control is to contain this phenomenon, increasing the damping of the system without changing its natural frequencies and vibration modes. A control of this type can improve the dynamic performance, reduce the vibratory phenomenon (and the resulting acoustic noise) and increase the fatigue strength of the system. The paper introduces a new approach to the synthesis of a modal controller to suppress vibrations in structures: it turns from the traditional formulation of the problem showing how the performance of the designed controller can be evaluated through the analysis of the resulting modal damping matrix of the controlled system. Such analysis allows to evaluate spillover effects, due to the presence of un-modeled modes, the stability of the control and the consequent effectiveness in reducing vibration. The ability to easily manage this information allows the synthesis of an efficient modal controller. Theoretical aspects are supported by experimental applications on a large flexible system.

Multi-frequency rotor vibration suppressing through self-optimizing control of electromagnetic force

2016 ◽  
Vol 23 (5) ◽  
pp. 701-715 ◽  
Author(s):  
Yao Jianfei ◽  
Gao Jinji ◽  
Wang Weimin
Keyword(s):  
Electromagnetic Force ◽  
Search Algorithm ◽  
Control Strategies ◽  
Active Vibration Control ◽  
Control Force ◽  
Rotor Vibration ◽  
Control Current ◽  
Active Vibration ◽  
Optimizing Control ◽  
Rotor Bearings

In this paper, the attention is confined to the suppression of multi-frequency rotor vibration. A method to control rotor’s multi-frequency periodic vibration in rotor-bearings system is proposed which uses active magnetic exciter (AME) to produce active control force to suppress rotor’s vibration and to reach a self-optimizing control of the rotor vibration. The control strategies include an arithmetic to optimize the amplitudes and phases of the control current using on-line self-optimizing algorithms in AME and applied multiple frequency-matched control force that AME generates to reduce the measured amplitudes of rotor. The model of rotor-bearings system with AME is established firstly. An active vibration control scheme for controlling transverse vibration of the rotor due to multi-frequency excitation is designed. The whole circle search algorithm and fast optimizing search algorithm about the amplitude and phase of control current are proposed. Finally, the experiments for controlling multi-frequency vibration of the rotor are carried out on the rotor-bearings test rig. The experimental results indicate that the proposed method can effectively suppress the rotor vibration for multi-frequency components through self-optimizing control of electromagnetic force.

Active Vibration Control of Rotating Machinery Using Piezoelectric Actuators Incorporating Flexible Casing Effects

1993 ◽  
Author(s):  
Timothy S. Barrett ◽  
Alan B. Palazzolo ◽  
Albert F. Kascak
Keyword(s):  
Active Vibration Control ◽  
Rotating Machinery ◽  
Modern Trend ◽  
Control Mechanisms ◽  
Control Force ◽  
Active Feedback ◽  
Flexible Designs ◽  
Active Vibration ◽  
The Stability ◽  
Support Housing

The modern trend toward lighter and more flexible designs in rotating machinery brings with it increasing demands for ways to dissipate the excess energy transferred to such structures by the action of dynamic forces. The present study incorporates the use of active feedback control mechanisms to suppress this unwanted vibration. The basic active damping scheme involves the introduction of a control force on the structure from a feedback network whose input is dictated by the motion of the structure. The control force is applied to the rotor bearing support housing via a piezoelectric actuator attached to the rotor casing. The current research extends previous electromechanical simulations by incorporating a flexible finite element shell model of the casing to support the actuator and sensors. Actuator and feedback loop dynamics are included in the stability and response simulation.

Zero Assignment in Vibration: With and Without Time Delay

2007 ◽  
Author(s):  
Kumar Vikram Singh ◽  
Biswa Nath Datta ◽  
Mayank Tyagi
Keyword(s):  
Time Delay ◽  
Control Strategy ◽  
Control Strategies ◽  
Small Time ◽  
State Feedback Control ◽  
Control Force ◽  
Sensors And Actuators ◽  
Full State Feedback ◽  
The Stability ◽  
Nodal Control

Control of the vibrating structures is desirable in various engineering applications for preventing fatigue and failure. It can be achieved by passive means using dynamic absorbers or by active means using sensors and actuators. In some cases, it is also not practical to apply a desirable control force in those locations at which dynamics of the structure to be controlled. In recent years, nodal control or dynamic absorption schemes are investigated in which control strategies to absorb a steady state motion of a desired location in the structure have been developed. Unlike conventional full-state feedback control which requires all the states of the system to be measured, nodal control strategy requires least numbers of sensors and actuators (depending upon the number of dynamic absorption points) for estimating the control gains and hence it may provide economical engineering solution. Nodal control problems are essentially a zero assignment problems in which a desired control is achieved by assigning zeroes to the prescribed locations in the structure. However while applying nodal control strategy by active means, small time delay from the sensors and actuators in the feedback loop is unavoidable and they influence the control gains as well as the stability of the system. In this paper we have developed nodal control strategy and obtained control gains for systems with and without time delays. Some examples related to conservative and nonconservative systems as well as realistic distributed parameter systems are presented to demonstrate the nodal control strategy and the effects of time delay on control gains.

Active Control of Rear Sub-Frame Vibration in Rear and All-Wheel Drive Vehicles

2016 ◽  
Author(s):  
J. Deng ◽  
A. R. Kashani
Keyword(s):  
Vibration Control ◽  
Active Control ◽  
Control Strategies ◽  
Active Vibration Control ◽  
Laboratory Evaluation ◽  
Advantages And Disadvantages ◽  
Gear Mesh ◽  
Wheel Drive ◽  
Active Vibration ◽  
Control Application

Feedback control of the rear sub-frame structure is used to abate its gear mesh induced vibration. The goal of the active control is to absorb vibration at a location close to the perturbation source, i.e., the rear differential. Proof mass actuators (PMAs) are used in this active vibration control application. A tuned absorption-based as well as a linear quadratic active vibration control schemes, each with its own advantages and disadvantages, were developed for this application. Following to the synthesis and numerical simulation of the two active vibration control strategies, they were first evaluated on a test structure in the laboratory. Following the laboratory evaluation, one of the active vibration control strategies was implemented on an all-wheel drive vehicle. Two small PMAs, mounted on the rear sub-frame of the vehicle, were used as the active elements in this vibration control application. An accelerometer placed next to each actuator was used as the feedback sensor. The effectiveness of active vibration control in absorbing the shaker induced vibration of the sub-frame was successfully demonstrated. In addition, rolling dynamometer tests showed effective vibration reduction of rear differential induced vibration of the sub-frame. As expected, lowering the sub-frame vibration resulted in lower vibration and noise in the cabin.

Active Vibration Control of Rotating Machinery Using Piezoelectric Actuators Incorporating Flexible Casing Effects

1995 ◽  
Vol 117 (1) ◽  
pp. 176-187 ◽  
Author(s):  
T. S. Barrett ◽  
A. B. Palazzolo ◽  
A. F. Kascak
Keyword(s):  
Active Vibration Control ◽  
Rotating Machinery ◽  
Modern Trend ◽  
Control Mechanisms ◽  
Control Force ◽  
Active Feedback ◽  
Flexible Designs ◽  
Active Vibration ◽  
The Stability ◽  
Support Housing

The modern trend toward lighter and more flexible designs in rotating machinery brings with it increasing demands for ways to dissipate the excess energy transferred to such structures by the action of dynamic forces. The present study incorporates the use of active feedback control mechanisms to suppress this unwanted vibration. The basic active damping scheme involves the introduction of a control force on the structure from a feedback network whose input is dictated by the motion of the structure. The control force is applied to the rotor bearing support housing via a piezoelectric actuator attached to the rotor casing. The current research extends previous electromechanical simulations by incorporating a flexible finite element shell model of the casing to support the actuator and sensors. Actuator and feedback loop dynamics are included in the stability and response simulation.

Active Vibration Control of a Flexible Beam Using a Buckling-Type End Force

2005 ◽  
Vol 128 (2) ◽  
pp. 278-286 ◽  
Author(s):  
Shahin Nudehi ◽  
Ranjan Mukherjee ◽  
Steven W. Shaw
Keyword(s):  
Vibration Control ◽  
Active Vibration Control ◽  
Lyapunov Stability Theory ◽  
Vibration Measurement ◽  
Flexible Beam ◽  
Control Force ◽  
Structural Elements ◽  
Physical Experiments ◽  
Active Vibration ◽  
The Stability

In this paper, we explore the use of end forces for vibration control in structural elements. The process involves vibration measurement and observer-based estimation of modal amplitudes, which are used to determine when to apply an end load such that it will remove vibration energy from the structure. For this study, we consider transverse vibration of a cantilever beam with a buckling-type end load that can be switched between two values, both of which are below the buckling load. The stability of the control system is proven using Lyapunov stability theory and its effectiveness is demonstrated using simulations and physical experiments. It is shown that the effectiveness of the approach is affected by the bandwidth of the actuator and the attendant characteristics of the filter, the level of the control force, and the level of bias in the end force. The experiments employ a beam fitted with a cable mechanism and motor for applying the end force, and a piezoelectric patch for taking vibration measurements. It is shown that the first two modes of the beam, whose natural frequencies are less than the bandwidth of the motor, are very effectively controlled by the proposed scheme.

A Mechanical Approach to the Design of Independent Modal Space Control for Vibration Suppression

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
S. Cinquemani ◽  
F. Resta
Keyword(s):  
Vibration Suppression ◽  
Dynamic Performance ◽  
Active Vibration Control ◽  
Flexible System ◽  
Damping Matrix ◽  
Modal Damping ◽  
Active Vibration ◽  
The Stability ◽  
Modal Space ◽  
Modal Controller

Many systems have, by their nature, a small damping and therefore they are potentially subjected to dangerous vibration phenomena. The aim of active vibration control is to contain this phenomenon, improve the dynamic performance of the system, and increase its fatigue strength. A way to reach this goal is to increase the system damping, preferably without changing its natural frequencies and vibration modes. In the past decades this has been achieved by developing the well-known independent modal space control (IMSC) technique. The paper describes a new approach to the synthesis of a modal controller to suppress vibrations in structures. It turns from the traditional formulation of the problem and it demonstrates how the performance of the controller can be evaluated through the analysis of the modal damping matrix of the controlled system. The ability to easily manage this information allows us to synthesize an efficient modal controller. Furthermore, it enables us to easily evaluate the stability of the control, the effects of spillover, and the consequent effectiveness in reducing vibration. Theoretical aspects are supported by experimental applications on a large flexible system.

Application of Combined Feedforward and Feedback Controller With Shaped Input to Benchmark Problem

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Young Joo Shin ◽  
Peter H. Meckl
Keyword(s):  
Feedback Control ◽  
Control Strategy ◽  
Control Strategies ◽  
Control Design ◽  
Single Frequency ◽  
Benchmark Problems ◽  
Control Force ◽  
Benchmark Problem ◽  
Advantages And Disadvantages ◽  
Robust Control Design

Benchmark problems have been used to evaluate the performance of a variety of robust control design methodologies by many control engineers over the past 2 decades. A benchmark is a simple but meaningful problem to highlight the advantages and disadvantages of different control strategies. This paper verifies the performance of a new control strategy, which is called combined feedforward and feedback control with shaped input (CFFS), through a benchmark problem applied to a two-mass-spring system. CFFS, which consists of feedback and feedforward controllers and shaped input, can achieve high performance with a simple controller design. This control strategy has several unique characteristics. First, the shaped input is designed to extract energy from the flexible modes, which means that a simpler feedback control design based on a rigid-body model can be used. In addition, only a single frequency must be attenuated to reduce residual vibration of both masses. Second, only the dynamics between control force and the first mass need to be considered in designing both feedback and feedforward controllers. The proposed control strategy is applied to a benchmark problem and its performance is compared with that obtained using two alternative control strategies.

Sign in / Sign up

Export Citation Format

Share Document