Design, analysis, and implementation of a new adaptive chatter control system in internal turning
12 Oct 2019-The International Journal of Advanced Manufacturing Technology (Springer London)-Vol. 104, Iss: 5, pp 1637-1659
TL;DR: It is proved that the presented control system can be effectively utilized in order to enhance the stability of active boring bar in deep internal turning operations.
Abstract: In this article, the adaptive control of chatter vibrations in internal turning operations is addressed. The single-input and single-output (SISO) control system is composed of an electrodynamic shaker as the controllable actuator, an integrated electronics piezoelectric (IEPE) accelerometer as the feedback sensor, and a newly proposed control algorithm. A novel adaptive direct velocity feedback (DVF) controller is developed on the basis of the energy balance concept. The suggested gain adaptation algorithm dynamically adjusts the value of controller gain by considering the mutual interaction between the control system and the cutting process. The aim of the adaptive DVF controller is to maintain a reasonable balance between the rate of positive energy generated by the actuator and the rate of destructive energy absorbed by the boring bar due to chatter phenomenon, such that the stability of cutting process is remarkably improved with minimized actuation cost. The performance of the proposed adaptive chatter control system is experimentally verified during the internal turning of Aluminum alloy 6063-T6. The value of critical limiting depth of cut is anticipated to be nearly 0.2 mm for the slender boring bar. During the impact experiments, it has been observed that the adaptive DVF controller enhances the dynamic stiffness of boring bar by 11.4-fold. In addition, with the help of the presented adaptive controller, the stable cutting process is successfully performed with the maximum cutting depth of 2 mm. It has been observed that the amplitude of chatter vibrations is efficiently attenuated by at least 60 dB, adjacent to the dominant bending mode of the boring bar. The periodic chatter waviness is eliminated from surface texture and the roughness of cut surface is remarkably improved. Finally, it is proved that the presented control system can be effectively utilized in order to enhance the stability of active boring bar in deep internal turning operations.
Citations
More filters
TL;DR: This article deals with identification of nonlinear dynamics and active control of boring bar chatter, which consists of an accelerometer sensor that monitors the cutting tool vibrations as well as an electrodynamic shaker that exerts a controllable force to a boring bar in the radial direction.
Abstract: This article deals with identification of nonlinear dynamics and active control of boring bar chatter A control system with unidirectional actuation is proposed, which consists of an accelerometer sensor that monitors the cutting tool vibrations as well as an electrodynamic shaker that exerts a controllable force to a boring bar in the radial direction The forward path model for actuator–boring bar assembly is identified using the fundamental concepts of system identification A novel parameter-varying transfer function is suggested to model the nonlinear dynamics of forward path, which originally stems from the cutting tool structure The proposed model describes the variations of system’s output response with respect to frequency and amplitude of input excitation The identified dynamic model is then utilized for model-based controller tuning The chatter control system utilizes a Direct Velocity Feedback (DVF) controller, and the optimal control gain is computed based upon the disturbance rejection criterion It is confirmed that the performance of optimally tuned DVF controller does not depend on variations of forward path dynamics The practical performance of optimal controller is experimentally verified by conducting impact tests as well as cutting tests on Aluminum alloy 6063-T6 According to the obtained results, the dynamic stiffness of active cutting tool is significantly improved by 20-fold Moreover, chatter is perfectly attenuated around the fundamental mode of boring bar The DVF controller efficiently attenuates the vibrations by 70 dB Finally, the viability of using an active cutting tool with embedded electromagnetic damper is studied for industrial applications
10 citations
TL;DR: In this paper , the authors extended the robotically assisted milling approach to consider an actively controlled robot arm, to suppress the chatter vibrations for milling operation, and the effect of active control is evaluated.
9 citations
TL;DR: In this article , the authors used the generated sound as operational information needed for adaptive control of the metalworking process and early monitoring and diagnosis of the condition of the machined materials using a newly introduced surface roughness quality index due to the sound-controlled machining process.
Abstract: The article aims to use the generated sound as operational information needed for adaptive control of the metalworking process and early monitoring and diagnosis of the condition of the machined materials using a newly introduced surface roughness quality index due to the sound-controlled machining process. The object of the measurement was correlation between the sound intensity generated during cutting and the material parameters of the machined surface, i.e., the roughness of the machined surface and the degree of wear of the cutting tool. The roughness was measured during longitudinal turning of a steel billet with a P25 insert made of 12X18H10T steel and a T15K6 cutting insert made of a titanium, cobalt, and tungsten group alloy. The correlation between the sound and roughness of the machined surface was 0.93, whereas between the sound and wear of the cutting tool was 0.93. The correlation between sound and tool wear in the experiment with P25 and T15K6 cutting inserts and the correlation between sound and roughness is positive.
4 citations
TL;DR: In this paper, a multi-objective evolutionary robust optimization of the boring process is proposed to achieve robust models for roughness and roundness concerning tool overhang length and borehole depth, set as noise variables.
Abstract: Boring is widely applied to enlarge holes. The high L/D ratio of boring bars enables self-excited vibration, deteriorating the quality of the hole. Therefore, this work aims the multi-objective evolutionary robust optimization of the boring process. Robust parameter design is employed to achieve robust models for roughness and roundness concerning tool overhang length and borehole depth, set as noise variables. These models aid the attainment of control factors’ levels, i.e., feed, cutting speed, and fixture position, which turn the responses less sensitive to noise. The robust models together with the material removal rate deterministic model are optimized through evolutionary multi-objective methods. The effects of process and noise factors are discussed considering literature. The multi-objective evolutionary optimization of the robust models helps to achieve these robust levels of process factors besides balancing the trade-off between the outcomes. The multi-objective robust evolutionary results outperform the scalarization approach considered for comparison purposes.
3 citations
TL;DR: In this article, the axial ultrasonic vibration-assisted boring (AUVB) method has been used for aviation deep-hole machining and the results demonstrate that AUVB has obvious advantages in reducing boring force, improving boring accuracy, suppressing vibration and promoting surface quality.
Abstract: Deep-holes are typical parts of aircraft structures, which is difficult to be machined. Boring assisted with ultrasonic vibration-assisted cutting has been proved to greatly enhance machining performance, especially for Ti6Al4V aviation alloy. This paper focuses on the machining extra-large aspect ratio (exceeding 20) of Ti6Al4V aviation deep-hole with the axial ultrasonic vibration-assisted boring (AUVB) method. First, the kinetics of the AUVB process is analyzed and a retrospective of its separation cutting feature is provided. Subsequently, a multi-stepped cantilever beam model of boring bar is established to analyze its static rigidity and dynamic stability. The aperture error is deduced, and then size coefficient is put forward to represent the static rigidity of the boring bar, which is inversely proportional to the diameter. In addition, two different vibration cases, namely modal-coupling vibration and regenerative vibration are considered for dynamic stability analysis. Next, the morphology of bored surface is analyzed, and the geometric height of peaks formed by AUVB and CB are calculated. Phase shift φ= π is suggested for obtaining a better surface in AUVB. Finally, the feasibility of AUVB on the machining of extra-large aspect ratio Ti6Al4V titanium alloy aviation deep-hole is verified through systematic experiments. Results demonstrate that AUVB has obvious advantages in reducing boring force, improving boring accuracy, suppressing vibration and promoting surface quality. Furthermore, the aperture error decreases to 50% and vibration amplitudes decrease to only 20–25%. The overall surface roughness of the deep-hole part stays below Ra=0.8μm with rotational speeds of 60r/min and 80r/min, and the surface residual stress state is transferred from the tensile state to a compressive one. As a result, not only AUVB can provide better boring accuracy and surface finish, but it also can enhance the surface fatigue properties.
1 citations
References
More filters
Book•
[...]
01 Jan 1989
TL;DR: Benefiting from the feedback of users who are familiar with the first edition, the material has been reorganized and rewritten, giving a more balanced and teachable presentation of fundamentals and applications.
Abstract: From the Publisher:
Written by two of the pioneers in the field, this book contains a wealth of practical information unavailable anywhere else. The authors give a comprehensive presentation of the field of adaptive control, carefully bending theory and implementation to provide the reader with insight and understanding. Benefiting from the feedback of users who are familiar with the first edition, the material has been reorganized and rewritten, giving a more balanced and teachable presentation of fundamentals and applications.
5,578 citations
Book•
13 Apr 2000TL;DR: In this paper, the authors discuss the application of metal cutting to manufacturing problems, including the design of real-time trajectory generation and interpolation algorithms, and CNC-oriented error analysis.
Abstract: Metal cutting is a widely used method of producing manufactured products. The technology of metal cutting has advanced considerably along with new materials, computers, and sensors. This new edition treats the scientific principles of metal cutting and their practical application to manufacturing problems. It begins with metal cutting mechanics, principles of vibration, and experimental modal analysis applied to solving shop floor problems. Notable is the in-depth coverage of chatter vibrations, a problem experienced daily by manufacturing engineers. The essential topics of programming, design, and automation of CNC (computer numerical control) machine tools, NC (numerical control) programming, and CAD/CAM technology are discussed. The text also covers the selection of drive actuators, feedback sensors, modeling and control of feed drives, the design of real time trajectory generation and interpolation algorithms, and CNC-oriented error analysis in detail. Each chapter includes examples drawn from industry, design projects, and homework problems. This book is ideal for advanced undergraduate and graduate students, as well as practicing engineers.
1,854 citations
Book•
06 Feb 1991
TL;DR: In this article, Figliola and Beasley first discuss the basics of measurement, analogue and digital data acquisition systems and signal processing, the statistics of measurement and the analysis of error and uncertainty.
Abstract: The assignment of numerical values to physical quantities underlies all quantitative statements in engineering and the physical sciences. This assignment is achieved by the process of measurement. The physical quantity being measured and the precision required in the numerical value determines the instrumentation to be used. The design of a measurement system therefore involves the analysis of the attribute to be measured, the means available for its detection and the verification that the measurement system performs as intended and can achieve the desired accuracy and precision. In this book Figliola and Beasley first discuss in general terms the basics of measurement, analogue and digital data acquisition systems and signal processing, the statistics of measurement and the analysis of error and uncertainty. In successive chapters they concentrate on the instruments and their physical basis in the areas of electricity, temperature, fluid flow, elastic strain and mechanics (displacement, motion, force and power). The coverage is directed towards measurements in various branches of engineering, with numerous worked examples and problems for students (approximately 30 to 40) at the end of each chapter. Since it is an American engineering text, the book uses both SI and English units. Unfortunately, the text is flawed by numerous errors. Some of the more egregious are that in chapter 1, `dimension' is used in place of `unit', the definitions given for the ampere and the ohm are in terms of `international' units that were abandoned in 1948 and derived units are expressed, for example, as `' in place of the standard forms (SI, ISO, ANSI) of `' or `'. There are furthermore numerous minor numerical errors and inconsistencies. One of the more serious flaws is the failure to distinguish between bias errors and uncertainty due to bias in the discussion of chapter 5. There is also a misuse of the student in the evaluation of uncertainty (although this error is not exclusively Figliola and Beasley's, since it occurs in ANSI documents on fluid flow measurement). Given the estimate for variance, with degrees of freedom, an uncertainty interval at confidence level p is properly , while the uncertainty for a combined quantity is where is evaluated from the Welch - Satterthwaite expression In spite of its shortcomings, the book collects a great deal of material in one place and, in the hands of a careful instructor who is aware of its flaws, could be useful as a supplementary text on measurement. E Richard Cohen
913 citations
TL;DR: A critical review of the different chatter suppression techniques can be found in this paper, where the evolution of each technique is described remarking the most important milestones in research and the corresponding industrial application.
454 citations
Book•
07 Feb 2008
TL;DR: The CtrlLAB tool as discussed by the authors is a feedback control system analysis and design tool for MATLAB functions that can be used to analyze feedback control systems. But it is not suitable for the analysis of linear control systems and does not support simulation of nonlinear systems.
Abstract: Preface 1. Introduction to feedback control 2. Mathematical models of feedback control systems 3. Analysis of Linear control systems 4. Simulation analysis of nonlinear systems 5. Model based controller design 6. PID controller design 7. Robust control systems design 8. Fractional-order controller - an introduction Appendix. CtrlLAB: a feedback control system analysis and design tool Bibliography Index of MATLAB functions Index.
370 citations