Cutting Force Adapted Control Application in Micropositioned Machining

2009 ◽  
Vol 3 (3) ◽  
pp. 263-270
Author(s):  
Joon Hwang ◽  
◽  
Eui-Sik Chung ◽  
Keyword(s):  
Cutting Force ◽  
Machining Process ◽  
Cutter Runout ◽  
Low Friction ◽  
Integral Control ◽  
Load Variation ◽  
Proportional Integral Control ◽  
Control Application ◽  
And Control ◽  
Chip Load

In the machining process, cutting force is a physical quantity well reflecting the process itself. Measured cutting force is used to identify the tool wear, surface roughness, chip formation, chatter stability and dynamic cutter runout problems. The cutting force linearity is used to measure and control the irregular cutting phenomena and machining process. We applied force-adaptive cutting control technology to evaluate chatter and real-time compensation for dynamic cutter runout. We proposed the concept of force-adaptive cutting control in the angle domain based upon proportional-integral control to control chip-load variation in machining. The micropositioning control of cutting tool or workpiece positioning using a low-friction sliding table and piezoelectric actuator changed the chip-load variation. Our results are expected to provide invaluable information in precision machining technology.

In-Process Compensation for Milling Cutter Runout via Chip Load Manipulation

1994 ◽  
Vol 116 (2) ◽  
pp. 153-160 ◽  
Author(s):  
S. Y. Liang ◽  
S. A. Perry
Keyword(s):  
Cutting Force ◽  
Control Strategy ◽  
End Milling ◽  
Learning Control ◽  
Cutter Runout ◽  
Machined Surface ◽  
Integral Control ◽  
Proportional Integral ◽  
Proportional Integral Control ◽  
Chip Load

This paper discusses a real-time chip load compensation methodology for the elimination of cutting force oscillation and machined surface scalloping due to cutter runout so as to gain better utilization of machine tools. The concept and implementation of the methodology is illustrated using end milling as a process of example. In this work a force feedback system was discussed in the angle domain based upon a proportional-integral control strategy and a repetitive learning control strategy to actively manipulate the chip load during end milling. Numerical simulations based on experimentally identified machining dynamics were presented to compare the performance of the two control schemes. Experimental investigation under various cutting conditions was performed to assess the viability of the feedback compensation system in the context of cutting force response as well as machined surface finish. It has been shown that a proportional-integral control has limited effectiveness in eliminating the runout-induced cutting force oscillation due to the constraints of system stability and dynamic performance. On the other hand, the learning control system based on the internal model principal successfully yields a cutting force free of oscillatory components at the spindle frequency and significantly improves the quality of machined surfaces by cancelling the nonasymptotically stable dynamics of cutter runout.

Characterization of Cutting Force Induced Surface Shape Variation in Face Milling Using High-Definition Metrology1

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Hai Trong Nguyen ◽  
Hui Wang ◽  
S. Jack Hu
Keyword(s):  
Cutting Force ◽  
Process Monitoring ◽  
Face Milling ◽  
Surface Shape ◽  
Machining Process ◽  
High Definition ◽  
Surface Patterns ◽  
Cutting Processes ◽  
And Control ◽  
The Impact

High-definition metrology (HDM) systems with fine lateral resolution are capable of capturing the surface shape on a machined part that is beyond the capability of measurement systems employed in manufacturing plants today. Such surface shapes can precisely reflect the impact of cutting processes on surface quality. Understanding the cutting processes and the resultant surface shape is vital to high-precision machining process monitoring and control. This paper presents modeling and experiments of a face milling process to extract surface patterns from measured HDM data and correlate these patterns with cutting force variation. A relationship is established between the instantaneous cutting forces and the observed dominant surface patterns along the feed and circumferential directions for face milling. Potential applications of this relationship in process monitoring, diagnosis, and control are also discussed for face milling. Finally a systematic methodology for characterizing cutting force induced surface variations for a generic machining process is presented by integrating cutting force modeling and HDM measurements.

scholarly journals Monitoring and Control of Cutting Forces in Machining Processes: A Review

2009 ◽  
Vol 3 (4) ◽  
pp. 445-456 ◽  
Author(s):  
Atsushi Matsubara ◽  
◽  
Soichi Ibaraki
Keyword(s):  
Cutting Force ◽  
Cutting Forces ◽  
Tool Path ◽  
Machining Process ◽  
Monitoring And Control ◽  
Machining Processes ◽  
Control Schemes ◽  
Process Monitoring And Control ◽  
Optimization Schemes ◽  
And Control

Much research has gone into machining process monitoring and control. This paper reviews monitoring and control schemes of cutting force and torque. Sensors to measure cutting force and torque, as well as their indirect estimation, are reviewed. Feedback control schemes and model-based feedforward scheduling schemes of cutting forces, as well as tool path optimization schemes for cutting force regulation, are reviewed. The authors’ works are also briefly presented.

Chip Load Kinematics in Milling With Radial Cutter Runout

1996 ◽  
Vol 118 (1) ◽  
pp. 111-116 ◽  
Author(s):  
J.-J. Junz Wang ◽  
S. Y. Liang
Keyword(s):  
Chip Thickness ◽  
Machining Process ◽  
Volume Distribution ◽  
Monitoring And Control ◽  
Cutter Runout ◽  
Validity Assessment ◽  
Thickness Prediction ◽  
Milling Forces ◽  
Chip Load ◽  
Chip Volume

This paper presents the analytical modeling of chip load and chip volume distribution in milling processes in the presence of cutter runout. The understanding of chip load kinematics has a strong bearing on the prediction of milling forces, on the assessment of resulting surface finish and tool vibration, and on the identification of runout for multi-toothed machining process monitoring and control. In this study a chip thickness expression is analytically established in terms of the number of flutes, the cutter offset location and the ratio of offset magnitude to feed per tooth. The effects of runout geometry, feed rate, and depths of cut on the overall chip generating action is discussed through the illustration of cutting regions and chip load maps. Explicit solutions for the entry and exit angles are formulated in the context of milling parameters and configuration. Experimental measurement of the resulting chip volumes from machining with an offset cutter is compared to an analytical model formulated from the chip thickness expression. Additionally, an average chip thickness prediction, based on the chip volume model in combination with the entry/exit angle solutions, is compared to data reported in the literature for validity assessment.

Chacterization of Cutting Force Induced Surface Shape Variation Using High-Definition Metrology

2012 ◽  
Author(s):  
Hai Trong Nguyen ◽  
Hui Wang ◽  
S. Jack Hu
Keyword(s):  
Cutting Force ◽  
Process Monitoring ◽  
Surface Shape ◽  
Machining Process ◽  
Monitoring And Control ◽  
High Definition ◽  
Surface Patterns ◽  
Cutting Processes ◽  
And Control ◽  
The Impact

High-definition metrology (HDM) systems with fine lateral resolution are capable of capturing the surface shape on a machined part that is beyond the scope of measurement systems employed in manufacturing plants today. Such surface shapes can precisely reflect the impact of cutting processes on surface quality. Understanding the cutting processes and the resultant surface shape is vital to identifying opportunities for high-precision machining process monitoring and control. This paper presents modeling and experiments of a face milling process to extract surface patterns from measured HDM data and correlate these patterns with cutting force variation. A relation is established between instantaneous cutting forces and the observed dominant patterns along the feed and circumferential directions. Potential applications of such relationship in process monitoring, diagnosis, and control are also discussed.

Adaptive Cutting Force Control with a Hybrid Axis System

2013 ◽  
Vol 7 (4) ◽  
pp. 378-384 ◽  
Author(s):  
Berend Denkena ◽  
◽  
Felix Flöter
Keyword(s):  
Cutting Force ◽  
Force Control ◽  
Cutting Forces ◽  
Major Effect ◽  
Machining Process ◽  
Surface Geometry ◽  
Milling Machines ◽  
Implementation Costs ◽  
Estimation And Control ◽  
And Control

Cutting forces have a major effect on the results of a machining process. High loads on the tool can lead to surface geometry and surface roughness that are less than optimal. However, due to its high implementation costs, cutting force control is not often used on milling machines. The paper presents a new approach by integrating a hybrid axis system in the force control loop. This offers a more dynamic and accurate way to influence cutting forces, but it also results in a more complex control problem. Therefore, how the nonlinear and time-varying characteristics of the cutting process can be modeled and considered for an automated operation is comprehensively shown. The interaction of process estimation and control is demonstrated with a PID-Control structure. Experimental results are presented.

A Music-Based Mechatronic System for Teaching Modeling and Control

2008 ◽  
Author(s):  
Vijay Shilpiekandula ◽  
Yun Seong Song
Keyword(s):  
Learning Experience ◽  
Innovative Teaching ◽  
Integral Control ◽  
Modeling And Control ◽  
Advanced Students ◽  
Hands On Learning ◽  
Rocking Motion ◽  
Design Tradeoffs ◽  
Proportional Integral Control ◽  
And Control

Audio-based tools can enhance the learning experience in introductory modeling and control classes at the undergraduate (sophomore) level in the mechanical engineering curriculum. An example audio-based learning tool that we propose is the “FlexSynth,” a servo-actuated flexural rocker arm that sways to an electronically generated music. We have built and tested the FlexSynth as part of a project under the MIT advanced graduate subject 2.737 Mechatronics class offered in Fall 2007. The angular range of the rocking motion of the flexural arm in the FlexSynth is mapped to a set of musical notes. While the flexural rocker swayed to the generated ‘command’ music, its motion is also converted into an equivalent ‘response’ music. Two speakers are used, one to play the commanded music and the other to play the response music. The performance of control algorithms (such as proportional or proportional-integral control) can be discerned from the command and response music, and compared for better musical quality. The appeal of an electromechanical system, driven by music and controlled to see the ‘dancing’ flexural rocker, makes the overall system an interesting show-and-tell for young kids or the public at large, getting them excited about science and engineering automation. Advanced control issues such as filtering of flexural damping modes of the rocker can also be addressed with this system implementation. Advanced students in the controls area can study the design tradeoffs between robustness and speed in following the command music. While the usual debugging tools such as multimeters, oscilloscopes, and dynamic signal analyzers allow for hands-on learning about the performance of a control system, an audio-based unit such as the FlexSynth can be a valuable addition to the innovative teaching tool kit.

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