scholarly journals INVESTIGATION OF LOCAL AND MODAL BASED ACTIVE VIBRATION CONTROL STRATEGIES ON THE EXAMPLE OF AN ELASTIC SYSTEM

2019 ◽  
Vol 19 (2) ◽  
pp. 32-45 ◽  
Author(s):  
Christoph PEUKERT ◽  
Patrick PÖHLMANN ◽  
Marcel MERX ◽  
Steffen IHLENFELDT ◽  
Jens MÜLLER
Keyword(s):  
Vibration Control ◽  
Machine Tools ◽  
Degrees Of Freedom ◽  
Elastic System ◽  
Control Strategies ◽  
Active Vibration Control ◽  
Modal Control ◽  
Control Approach ◽  
Control Loops ◽  
The Impact

Nowadays, feed axes are often equipped with multiple parallel-acting actuators in order to increase the dynamics of the machine tool. Also, additional actuators for active damping are widely used. Normally, the drives or actuators are controlled independently without consideration for the impact on each other. In contrast, by using the modal space control, the system can be decoupled and the modal control loops can be adjusted independently. This control approach is particularly suitable for motion systems, such as machine tools, which have more drives or actuators than degrees of freedom of movement. This paper deals with the pre-investigation of the modal-based vibration control for machine tools with additional actuators. The object of investigation is an elastic system with a movable saddle. The modal-based control is compared with a local control approach. The results obtained experimentally on the test rig are presented. The modal control is superior since, with the modal approach, each control loop corresponds to a specific vibration mode, and the control law for this loop is designed to provide the desired performance of the control system at the corresponding resonance frequency. The parameterisation of the control loops is simplified by modal control, since the modes can be controlled independently.

scholarly journals Adaptive Active Vibration Control for Machine Tools with Highly Position-Dependent Dynamics

2018 ◽  
Vol 12 (5) ◽  
pp. 631-641 ◽  
Author(s):  
Robin Kleinwort ◽  
◽  
Jonathan Platz ◽  
Michael F. Zaeh
Keyword(s):  
Vibration Control ◽  
Machine Tools ◽  
Material Removal ◽  
Control Strategies ◽  
Active Vibration Control ◽  
Adaptive Controller ◽  
Depth Of Cut ◽  
Removal Rates ◽  
Active Vibration ◽  
Free Material

The material removal rates of machine tools are often limited by chatter, which is caused by the machine’s most flexible structural modes. Active vibration control systems mitigate chatter vibrations and increase the chatter free axial depth of cut. However, model-based control strategies reach their limit if the machine tool exhibits highly position-dependent dynamics. In this paper, an adaptive control strategy is presented. This strategy uses online system identification to adapt the controller. The adaption algorithm is mainly automated. However, a few parameters still need to be selected. Therefore, a methodology for the determination of the optimal parameters is proposed. The adaptive controller was implemented on a B&R PLC and its suitability was verified experimentally by the observation of notable increases in the chatter-free material removal rates.

Robust vibration control of flexible panel: modeling and simulation

2017 ◽  
Vol 14 (5) ◽  
pp. 433-442
Author(s):  
Aalya Banu ◽  
Asan G.A. Muthalif
Keyword(s):  
Robust Control ◽  
Vibration Control ◽  
Controller Design ◽  
Control Strategies ◽  
Active Vibration Control ◽  
Flexible Structures ◽  
Parametric Uncertainty ◽  
Design Algorithm ◽  
Content Type ◽  
And Performance

Purpose This paper aims to develop a robust controller to control vibration of a thin plate attached with two piezoelectric patches in the presence of uncertainties in the mass of the plate. The main goal of this study is to tackle dynamic perturbation that could lead to modelling error in flexible structures. The controller is designed to suppress first and second modal vibrations. Design/methodology/approach Out of various robust control strategies, μ-synthesis controller design algorithm has been used for active vibration control of a simply supported thin place excited and actuated using two piezoelectric patches. Parametric uncertainty in the system is taken into account so that the robust system will be achieved by maximizing the complex stability radius of the closed-loop system. Effectiveness of the designed controller is validated through robust stability and performance analysis. Findings Results obtained from numerical simulation indicate that implementation of the designed controller can effectively suppress the vibration of the system at the first and second modal frequencies by 98.5 and 88.4 per cent, respectively, despite the presence of structural uncertainties. The designed controller has also shown satisfactory results in terms of robustness and performance. Originality/value Although vibration control in designing any structural system has been an active topic for decades, Ordinary fixed controllers designed based on nominal parameters do not take into account the uncertainties present in and around the system and hence lose their effectiveness when subjected to uncertainties. This paper fulfills an identified need to design a robust control system that accommodates uncertainties.

scholarly journals Experimental implementation of artificial neural network-based active vibration control & chatter suppression

2021 ◽  
Author(s):  
Yong Xia
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Artificial Neural Network ◽  
Control System ◽  
Vibration Control ◽  
Control Strategies ◽  
Active Vibration Control ◽  
Chatter Suppression ◽  
Active Vibration ◽  
Artificial Neural

Vibration control strategies strive to reduce the effect of harmful vibrations such as machining chatter. In general, these strategies are classified as passive or active. While passive vibration control techniques are generally less complex, there is a limit to their effectiveness. Active vibration control strategies, which work by providing an additional energy supply to vibration systems, on the other hand, require more complex algorithms but can be very effective. In this work, a novel artificial neural network-based active vibration control system has been developed. The developed system can detect the sinusoidal vibration component with the highest power and suppress it in one control cycle, and in subsequent cycles, sinusoidal signals with the next highest power will be suppressed. With artificial neural networks trained to cover enough frequency and amplitude ranges, most of the original vibration can be suppressed. The efficiency of the proposed methodology has been verified experimentally in the vibration control of a cantilever beam. Artificial neural networks can be trained automatically for updated time delays in the system when necessary. Experimental results show that the developed active vibration control system is real time, adaptable, robust, effective and easy to be implemented. Finally, an experimental setup of chatter suppression for a lathe has been successfully implemented, and the successful techniques used in the previous artificial neural network-based active vibration control system have been utilized for active chatter suppression in turning.

Distributed active vibration cooperative control for flexible structure with multiple autonomous substructure model

2020 ◽  
Vol 26 (21-22) ◽  
pp. 2026-2036
Author(s):  
Xiangdong Liu ◽  
Haikuo Liu ◽  
Changkun Du ◽  
Pingli Lu ◽  
Dongping Jin ◽  
...  
Keyword(s):  
Vibration Control ◽  
Cooperative Control ◽  
Vibration Suppression ◽  
Control Strategies ◽  
Active Vibration Control ◽  
Flexible Structures ◽  
Lyapunov Theory ◽  
Sensors And Actuators ◽  
Active Vibration ◽  
Distributed Cooperative Control

The objective of this work was to suppress the vibration of flexible structures by using a distributed cooperative control scheme with decentralized sensors and actuators. For the application of the distributed cooperative control strategy, we first propose the multiple autonomous substructure models for flexible structures. Each autonomous substructure is equipped with its own sensor, actuator, and controller, and they all have computation and communication capabilities. The primary focus of this investigation was to illustrate the use of a distributed cooperative protocol to enable vibration control. Based on the proposed models, we design two novel active vibration control strategies, both of which are implemented in a distributed manner under a communication network. The distributed controllers can effectively suppress the vibration of flexible structures, and a certain degree of interaction cooperation will improve the performance of the vibration suppression. The stability of flexible systems is analyzed by the Lyapunov theory. Finally, numerical examples of a cantilever beam structure demonstrate the effectiveness of the proposed methods.

A HIGHER ORDER FINITE ELEMENT MODELING OF PIEZOLAMINATED SMART COMPOSITE PLATES AND ITS APPLICATION TO ACTIVE VIBRATION CONTROL

2007 ◽  
Vol 04 (01) ◽  
pp. 141-162 ◽  
Author(s):  
V. BALAMURUGAN ◽  
B. MANIKANDAN ◽  
S. NARAYANAN
Keyword(s):  
Finite Element ◽  
Vibration Control ◽  
Degrees Of Freedom ◽  
Active Vibration Control ◽  
Composite Plates ◽  
Piezoelectric Sensor ◽  
Higher Order ◽  
Interpolation Function ◽  
Smart Composite ◽  
Active Vibration

This paper presents a higher order — field consistent — piezolaminated 8-noded plate finite element with 36 elastic degrees-of-freedom per element and two electric degrees-of-freedom per element, one each for the piezoelectric sensor and actuator. The higher order plate theory used satisfies the stress and displacement continuity at the interface of the composite laminates and has zero shear stress on the top and bottom surfaces. The transverse shear deformation is of a higher order represented by the trigonometric functions allowing us to avoid the shear correction factors. In order to maintain the field consistency, the inplane displacements, u and v are interpolated using linear shape functions, the transverse displacement w is interpolated using hermite cubic interpolation function, while rotations θx and θy are interpolated using quadratic interpolation function. The element is developed to include stiffness and the electromechanical coupling of the piezoelectric sensor/actuator layers. The active vibration control performance of the piezolaminated smart composite plates has been studied by modeling them with the above element and applying various control strategies.

Simulation-Based Dimensioning of the Required Actuator Force for Active Vibration Control

2018 ◽  
Vol 12 (5) ◽  
pp. 658-668 ◽  
Author(s):  
Robin Kleinwort ◽  
◽  
Philipp Weishaupt ◽  
Michael F. Zaeh
Keyword(s):  
Machine Tool ◽  
Vibration Control ◽  
Machine Tools ◽  
Active Vibration Control ◽  
Depth Of Cut ◽  
Force Model ◽  
Machining Processes ◽  
Simulation Based ◽  
Active Vibration ◽  
The Right

The material removal rates of machine tools are often limited by chatter, which is caused by the machine’s most flexible structural modes. Active vibration control systems mitigate chatter vibrations and increase the chatter-free depth of cut. The systems can be used for already-in-use machine tools in particular as a retrofit solution. Unfortunately, no dimensioning techniques exist to help in finding the right actuator size required for a specific machine tool. This publication presents a simulation-based dimensioning methodology that determines, based on a stability analysis, the required actuator force and bandwidth. First, the critical machining processes, based on machine tool specific parameters, are identified. Then, the required actuator force and bandwidth are determined with the help of a coupled simulation model that consists of a cutting force model, the machine’s structural dynamics, and a model of the active vibration control system.

scholarly journals Active vibration control for a CNC milling machine

2013 ◽  
Vol 228 (2) ◽  
pp. 230-245 ◽  
Author(s):  
DG Ford ◽  
A Myers ◽  
F Haase ◽  
S Lockwood ◽  
A Longstaff
Keyword(s):  
Control System ◽  
Tool Wear ◽  
Machine Tool ◽  
Vibration Control ◽  
Surface Finish ◽  
Machine Tools ◽  
Active Vibration Control ◽  
Milling Machine ◽  
Cnc Machine ◽  
Active Vibration

There is a requirement for improved three-dimensional surface characterisation and reduced tool wear when modern computer numerical control (CNC) machine tools are operating at high cutting velocities, spindle speeds and feed rates. For large depths of cut and large material removal rates, there is a tendency for machines to chatter caused by self-excited vibration in the machine tools leading to precision errors, poor surface finish quality, tool wear and possible machine damage. This study illustrates a method for improving machine tool performance by understanding and adaptively controlling the machine structural vibration. The first step taken is to measure and interpret machine tool vibration and produce a structural model. As a consequence, appropriate sensors need to be selected and/or designed and then integrated to measure all self-excited vibrations. The vibrations of the machine under investigation need to be clearly understood by analysis of sensor signals and surface finish measurement. The active vibration control system has been implemented on a CNC machine tool and validated under controlled conditions by compensating for machine tool vibrations on time-varying multi-point cutting operations for a vertical milling machine. The design of the adaptive control system using modelling, filtering, active vibration platform and sensor feedback techniques has been demonstrated to be successful.

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