http://www-personal.umich.edu/~ykoren/uploads/Advanced_controllers_for_feed_drives.pdf

Advanced Controllers for Feed Drives

The increase in awareness regarding the need to optimise manufacturing process efficiency has led to a great deal of research aimed at machine tool condition monitoring. This paper considers the application of condition monitoring techniques to the detection of cutting tool wear and breakage during the milling process. Established approaches to the problem are considered and their application to the next generation of monitoring systems is discussed. Two approaches are identified as being key to the industrial application of operational tool monitoring systems. Multiple sensor systems, which use a wide range of sensors with an increasing level of intelligence, are seen as providing long-term benefits, particularly in the field of tool wear monitoring. Such systems are being developed by a number of researchers in this area. The second approach integrates the control signals used by the machine controller into a process monitoring system which is capable of detecting tool breakage. Initial findings mainly under laboratory conditions, indicate that both these approaches can be of major benefit. It is finally argued that a combination of these approaches will ultimately lead to robust systems which can operate in an industrial environment.

An overview of approaches to end milling tool monitoring

Computerized Predictive Cutting Models for Forces in End-Milling Including Eccentricity Effects

The author has been conducting research in the area of metal cutting mechanics, metal cutting dynamics, machine tool vibrations, precision machining and machine tool control in his Manufacturing Automation Laboratory, at The University of British Columbia, Canada since 1986. This article summarizes the research conducted in mechanics and dynamics of metal cutting in our laboratory. Modeling of mechanics of metal cutting is summarized first. The models include orthogonal to oblique cutting transformation, mechanistic modeling of cutting coefficients, slip line field and Finite Element modeling. The author mostly focused on milling. The kinematics of milling with and without structural vibrations is modeled. The geometric model of end mills and inserted cutters with arbitrary geometry are modeled. The prediction of forces, torque, power and dimensional surface finish is explained for milling operations. The chatter stability for milling operations is presented. The metal cutting knowledge is transf...

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Modeling approaches and software for predicting the performance of milling operations at mal-ubc

George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0405 This paper presents the establishment of a closed form expression for the dynamic forces as explicit functions of cutting parameters and tool/workpiece geometry in milling processes. Based on the existing local cutting force model, the generation of total cutting forces is formulated as the angular domain convolution of three cutting process component functions, namely the elementary cutting function, the chip width density function, and the tooth sequence function. The elemental cutting force function is related to the chip formation process in an elemental cutting area and it is characterized by the chip thickness variation, and radial cutting configuration. The chip width density function defines the chip width per unit cutter rotation along a cutter flute within the range of axial depth of cut_ The tooth sequence function represents the spacing between flutes as well as their cutting sequence as the cutter rotates. The analysis of cutting forces is extended into the Fourier domain by taking the frequency multiplication of the transforms of the three component functions. Fourier series coefficients of the cutting forces are shown to be explicit algebraic functions of various tool parameters and cutting conditions. Numerical simulation results are presented in the frequency domain to illustrate the effects of various process parameters. A series of end milling experiments are performed and their results discussed to validate the analytical model.

S. Zombach

Papers

A Method for Cutting Force Evaluation of End Mills