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

Table 5

Differences in time and feed depth between the values identified by the detection algorithm and the measured value.

Test number	CFRP entering		interface transit		Ti exit
	Drilling time (s)	Drilling depth (mm)	Drilling time (s)	Drilling depth (mm)	Drilling time (s)	Drilling depth (mm)
1	0.417	0.083	0.196	0.039	−4.970	−0.994
2	0.269	0.054	−0.115	−0.023	−0.150	−0.030
3	0.325	0.065	0.092	0.018	−2.236	−0.447
4	0.290	0.058	−0.234	−0.047	−0.021	−0.004
5	0.305	0.061	0.162	0.032	−0.383	−0.077
6	0.260	0.052	0.230	0.046	−4.621	−0.924
7	0.310	0.062	0.148	0.030	−1.657	−0.331
8	0.290	0.058	−0.032	−0.006	−0.853	−0.171
9	0.260	0.052	−0.123	−0.025	−1.110	−0.222
10	0.267	0.053	−0.165	−0.033	−1.512	−0.302
11	0.450	0.090	0.366	0.073	−1.155	−0.231
12	0.260	0.052	−0.092	−0.018	−4.430	−0.886
13	0.310	0.062	−0.121	−0.024	−3.760	−0.752
14	0.320	0.064	−0.123	−0.025	−3.380	−0.676
15	0.290	0.058	−0.160	−0.032	−0.660	−0.132
16	0.300	0.060	−0.162	−0.032	−3.320	−0.664
17	0.470	0.094	−0.130	−0.026	−5.340	−1.068
18	0.252	0.050	−0.063	−0.013	−4.780	−0.956
19	0.260	0.052	−0.100	−0.020	−0.270	−0.054
20	0.470	0.094	0.072	0.014	−2.330	−0.466
21	0.230	0.046	−0.072	−0.014	−1.860	−0.372
22	0.226	0.045	−0.026	−0.005	−1.999	−0.400
23	0.340	0.068	0.074	0.015	−1.400	−0.280
24	0.300	0.060	−0.070	−0.014	−6.010	−1.202