A Force Sensorless Method for CFRP/Ti Stack Interface Detection during Robotic Orbital Drilling Operations

Table 3

Comparison of measured and observed thrust force when drilling CFRP and Ti layers.

Test number	Thrust force when drilling CFRP				Thrust force when drilling Ti
	Measured (N)	Observed (N)	(N)	Deviation (%)	Measured (N)	Observed (N)	(N)	Deviation (%)
1	83.47	85.91	10.27	11.95	277.00	259.07	24.01	8.67
2	99.28	102.19	11.76	11.85	312.23	298.61	21.06	6.75
3	109.13	106.52	11.94	10.94	349.95	317.21	37.21	10.63
4	118.96	116.17	17.20	14.46	378.93	343.22	38.24	10.09
5	129.35	126.10	11.61	8.98	393.47	362.31	36.16	9.19
6	132.88	128.39	11.85	8.92	425.12	401.00	29.84	7.02
7	139.02	139.82	12.79	9.20	442.30	412.64	35.36	7.99
8	152.06	146.17	13.54	8.90	464.38	429.31	39.47	8.50
9	151.38	148.21	12.27	8.11	471.32	414.53	58.46	12.40
10	157.83	157.46	13.66	8.65	489.12	455.81	36.67	7.50
11	149.78	151.66	15.78	10.54	510.27	457.20	54.58	10.70
12	162.59	159.46	11.05	6.80	548.53	511.78	36.62	6.68
13	169.51	161.96	12.72	7.50	542.07	482.16	59.99	11.07
14	168.87	166.10	14.53	8.60	553.20	499.88	53.58	9.69
15	172.47	168.19	16.37	9.49	570.95	526.67	45.13	7.90
16	172.63	162.19	16.22	9.40	589.04	535.50	54.23	9.21
17	180.10	172.47	21.31	11.83	609.20	548.91	61.43	10.08
18	182.53	175.50	16.36	8.96	627.18	576.45	52.51	8.37
19	205.38	196.45	17.20	8.37	495.66	453.04	45.37	9.15
20	196.28	187.14	16.81	8.56	652.28	597.01	58.32	8.94
21	195.24	181.41	21.12	10.82	648.23	595.99	57.13	8.81
22	200.63	190.24	17.80	8.87	679.41	630.90	52.20	7.68
23	196.72	181.05	18.59	9.45	683.71	635.91	50.34	7.36
24	203.80	194.89	19.53	9.58	713.97	651.37	64.55	9.04