Jonathan Abir

Virtual metrology frame technique for improving dynamic performance of a small size machine tool

Precision Engineering, Apr 1, 2017

This paper presents a novel concept, a virtual metrology frame, for enhancing the dynamic perform... more This paper presents a novel concept, a virtual metrology frame, for enhancing the dynamic performance of a machine tool with a flexible structural frame. The dynamic properties of a machine are directly affected by the stiffness of its frame, and its reference system; thus, by having an unstressed metrology frame, superior dynamic capabilities can be achieved. The developed concept does not require physical components associated with metrology frame; hence it is ideal for machine tools with requirements for small footprint and ultra-precision performance. The concept relies on an accelerometer based dynamic displacement feedback technique, where the accelerometer is used as a precision frame displacement sensor. The concept does not require a complex controller, and was realized in an off-the-shelf CNC controller. The concept was demonstrated on a linear motion system, a simplified version of a compact size CNC machine, and its servo bandwidth and dynamic stiffness were improved by 36% and 70% respectively, which are the key parameters for improving the machining accuracy.

Download

A novel accelerometer based feedback concept for improving machine dynamic performance

IFAC-PapersOnLine, 2016

Small size ultra-precision Computer Numerical Control (CNC) machines require high dynamic perform... more Small size ultra-precision Computer Numerical Control (CNC) machines require high dynamic performance. Flexible frame phenomena can limit the machine dynamic performance, particularly in small size machines. A novel accelerometer based feedback concept for improving machine dynamic performance was developed and realised, a virtual metrology frame. It expends the limited techniques for improving dynamic performance of a small size machine by measuring the flexible frame displacement, and feeding it into the controller. The concept was implemented in a simplified linear motion system, and showed a 12dB reduction in the magnitude of the first resonance in the plant frequency response function. This allowed improving the servo bandwidth by 58% based on a PID controller. A new technique for real-time dynamic displacement measurements using accelerometer was developed. It shows a low sensor noise σ<30 nm; thus, accelerometers are used as a displacement sensor in a control system.

Download

A Novel Scattering Model for Determination of Surface Defects in Infra-Red Optical Fibers Based on Spectral Measurements

a novel method for determination of mechanical defects in optical fibers based on unitless parame... more

A Novel Scattering Model for Determination of Surface Defects in Infra-Red Optical Fibers Based on Spectral Measurements

by Jonathan Abir and Dan Regelman

Workshop on Specialty Optical Fibers and their Applications, 2013

ABSTRACT a novel method for determination of mechanical defects in optical fibers based on unitle... more

Uploads

Papers by Jonathan Abir

Log In