Diamond turning using position and AE dual feedback control system

A control scheme to improve machining accuracy by means of an acoustic emission root mean square (AErms) signal measured on-line during diamond turning is proposed. Preliminary experiments have verified a correlation between a machining error and measured AErms. Based on the correlation, a control algorithm to apply a compensation signal to a position feedback control loop, named the position and AE dual feedback control scheme is proposed. Machining tests using a diamond turning machine controlled with a PC-based open architecture controller showed that the proposed control scheme accomplishes 20% reduction of machining error compared to conventional position feedback control. Machining tests using new and worn diamond tools showed that an on-line tool-wear recognition is possible using the AE feedback control system.