Title

A dynamic analysis and lobing control in the shoe centerless grinding process

Date of Completion

January 1995

Abstract

An experimental and analytical study was conducted on the dynamics of the shoe centerless grinding (SCG) to reveal the operating mechanism and provide a lobing control algorithm. Through this study, the work holding stability condition was found and the work holding stability chart was produced.^ It is found that rounding stability is determined by the time delay ratio (T$\sb2$/T$\sb1$ = ($180-\beta)/\alpha\rbrack$, and the forced lobing frequency is determined by speed ratio (grinding wheel rpm to workpiece rpm).^ A new active lobing control algorithm, called "active time-delay control with shaped disturbance", is proposed. It makes use of the periodic disturbance as a shaped control input to add another time delay feedback into system such that regenerative error is cancelled and the system is stabilized. This approach provides a generally effective means for eliminating processing error by using an additional external disturbance in the system which has the regenerative effect. ^