Table 4.

Tool wear performance estimation results of four networks.

Methods	PCC	Relative Accuracy	MAE	RMSE	Standard Deviation
CNN [36]	0.7957	0.7898	40.2158	56.3456	44.3952
CNN Blocks	0.9258	0.8097	34.0152	41.8622	28.8696
GRU	0.1947	0.6383	56.6794	70.6391	70.6137
PECG	0.9538	0.8522	23.8362	28.5240	22.2840

Bold indicates optimal performance.