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.

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.

Active vibration control development in ultra‐precision machining

2020 ◽  
pp. 107754632093347 ◽  
Author(s):  
Francesco Aggogeri ◽  
Angelo Merlo ◽  
Nicola Pellegrini
Keyword(s):  
Control System ◽  
Machine Tool ◽  
Vibration Control ◽  
Active Vibration Control ◽  
Hard Material ◽  
Tool Holder ◽  
Machining Vibrations ◽  
Active Vibration ◽  
Cutting Processes ◽  
Adaptive Regulator

This study presents a combined feedback–feedforward adaptive regulator applied to an active vibration control tool holder platform to contain the effect of machining vibrations. The proposed mechatronic solution can be integrated in a milling machine tool as an interface between the beam ( Z-axis) and the tool holder. The aim is to counteract vibrations in the broadband frequency range (100 Hz–900 Hz), controlling the tool position in real time. The active vibration control system is based on the harmonic steady-state concept due to the sinusoidal representation of the disturbance signals. The study focuses on the regulator architecture and the main logics applied to satisfy the required performance. A full investigation is executed through simulations and experimental campaigns, proving the disturbance reduction. The active vibration control system is implemented on a 4-axis machine tool and validated using multitonal disturbances. The system is evaluated in compensating a set of undesired effects, such as vibrations generated by unbalanced tools or hard material cutting processes. The obtained results show a maximum reduction of the vibration amplitude by 43.7% at the critical frequency.

Multivariable control of active vibration compensation modules of a portal milling machine

2016 ◽  
Vol 24 (1) ◽  
pp. 3-17 ◽  
Author(s):  
Christian Brecher ◽  
Marcel Fey ◽  
Birk Brockmann ◽  
Prateek Chavan
Keyword(s):  
Vibration Control ◽  
Machine Tools ◽  
Test Bench ◽  
Dynamic Behaviour ◽  
Active Vibration Control ◽  
Depth Of Cut ◽  
Milling Machine ◽  
Modal Parameter ◽  
Cutting Depth ◽  
Active Vibration

The Z-ram of a Portal Milling machine presents a weak point in the dynamic behaviour of the machine tool which makes it prone to the occurrence of chatter vibration. Since chatter vibrations directly limit the maximum allowable cutting depth during machining, an improvement in dynamic behaviour of the machine tools by means of active vibration control of the spindle will result in an increase of maximum cutting depth. An active vibration control of the Tool Center Point of a Portal Milling machine using four hydraulic compensation modules integrated in the Z-ram structure is proposed. A test bench for the Z-ram was constructed at Machine Tools Laboratory (WZL) of RWTH Aachen University and it’s modal analysis revealed the occurring dominant vibration mode. A polyreference-LSCF modal parameter estimation was employed for identification of the measured MIMO Frequency Response Functions (FRF) of the Z-ram test bench. Using this mathematical model, the MIMO controller was synthesized with the Glover-McFarlane [Formula: see text] Loop Shaping Design procedure. The implementation of the controller on the test bench resulted in significant improvement in the compliance behaviour of the Z-ram structure. The dynamic compliance at dominant mode of vibration at 75 Hz was reduced by a factor of 3.5. Furthermore, the attenuation of the maximum negative real part resulted in a direct increase in maximum stable depth of cut by a factor of 2.1.

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.

Characteristics of active vibration control system using gyro-stabilizer

1998 ◽  
Vol 20 (3) ◽  
pp. 176-183 ◽  
Author(s):  
Hiroto Higashiyama ◽  
Masaaki Yamada ◽  
Yukihiko Kazao ◽  
Masao Namiki
Keyword(s):  
Control System ◽  
Vibration Control ◽  
Active Vibration Control ◽  
Active Vibration
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