## Doctoral Dissertations

#### Title

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

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. ^

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