Table 1.
Experimental results of human following.
| Parameters | Exp. 1 | Exp. 2 | Exp. 3 | Exp. 4 | Exp. 5 | Exp. 6 | Exp. 7 |
|---|---|---|---|---|---|---|---|
| Mission success rate (%) | O | O | O | O | O | O | x |
| Target’s travel distance (m) | 28.06 | 27.93 | 28.08 | 28.42 | 27.97 | 27.74 | 0.00 |
| Robot’s travel distance (m) | 25.77 | 26.95 | 26.86 | 27.65 | 26.88 | 26.46 | 18.58 |
| Robot’s travel time (s) | 44.28 | 42.16 | 43.44 | 45.68 | 42.18 | 42.39 | 68.96 |
| Robot’s average velocity (m/s) | 0.58 | 0.64 | 0.62 | 0.61 | 0.64 | 0.62 | 0.27 |
| # of frames | 1042 | 1024 | 1022 | 1120 | 932 | 992 | 1507 |
| Successfully tracked (frames) | 1030 | 997 | 1010 | 1108 | 928 | 982 | 679 |
| Lost track of the target (frames) | 12 | 27 | 12 | 12 | 4 | 10 | 828 |
| Successfully tracked (s) | 43.77 | 41.04 | 42.93 | 45.19 | 42.00 | 41.96 | 31.07 |
| Lost track of the target (s) | 0.51 | 1.11 | 0.51 | 0.49 | 0.18 | 0.43 | 37.89 |
| Lost track of the target rate (%) | 1.2 | 2.6 | 1.2 | 1.1 | 0.4 | 1.0 | 54.9 |
| Successful tracking rate (%) | 98.8 | 97.4 | 98.8 | 98.9 | 99.6 | 99.0 | 45.1 |
| Computation time (fps) | 23.53 | 24.29 | 23.53 | 24.52 | 22.10 | 23.40 | 21.85 |
| Parameters | Exp. 8 | Exp. 9 | Exp. 10 | Exp. 11 | Exp. 12 | Exp. 13 | Exp. 14 |
| Mission success rate (%) | x | O | O | O | O | O | O |
| Target’s travel distance (m) | 0.00 | 27.93 | 27.37 | 27.40 | 28.79 | 27.85 | 28.05 |
| Robot’s travel distance (m) | 10.94 | 27.08 | 26.43 | 25.89 | 27.21 | 26.45 | 25.82 |
| Robot’s travel time (s) | 39.93 | 44.53 | 44.27 | 41.22 | 42.82 | 44.58 | 42.90 |
| Robot’s average velocity (m/s) | 0.27 | 0.61 | 0.60 | 0.63 | 0.64 | 0.59 | 0.60 |
| # of frames | 961 | 1042 | 987 | 999 | 1026 | 1017 | 991 |
| Successfully tracked (frames) | 479 | 969 | 983 | 994 | 994 | 941 | 973 |
| Lost track of the target (frames) | 482 | 73 | 4 | 5 | 32 | 76 | 18 |
| Successfully tracked (s) | 19.90 | 41.41 | 44.09 | 41.01 | 41.48 | 41.25 | 42.12 |
| Lost track of the target (s) | 20.03 | 3.12 | 0.18 | 0.21 | 1.34 | 3.33 | 0.78 |
| Lost track of the target | 50.2 | 7.0 | 0.4 | 0.5 | 3.1 | 7.5 | 1.8 |
| Successful tracking rate (%) | 49.8 | 93.0 | 99.6 | 99.5 | 96.9 | 92.5 | 98.2 |
| Computation time (fps) | 24.07 | 23.40 | 22.29 | 24.24 | 23.96 | 22.81 | 23.10 |
| Parameters | Exp. 15 | Exp. 16 | Exp. 17 | Exp. 18 | Total | Average | Std |
| Mission success rate (%) | O | O | O | O | 88.9% | - | - |
| Target’s travel distance (m) | 26.68 | 28.17 | 28.08 | 26.37 | 444.89 | 24.72 | 9.01 |
| Robot’s travel distance (m) | 25.80 | 26.83 | 25.35 | 23.86 | 450.80 | 25.04 | 4.06 |
| Robot’s travel time (s) | 44.06 | 42.15 | 41.72 | 39.87 | 797.12 | 44.28 | 6.36 |
| Robot’s average velocity (m/s) | 0.59 | 0.64 | 0.61 | 0.60 | - | 0.57 | 0.11 |
| # of frames | 984 | 1029 | 940 | 948 | 18,563.0 | 1031.3 | 126.78 |
| Successfully tracked (frames) | 956 | 1003 | 923 | 908 | 16,857.0 | 936.5 | 141.83 |
| Lost track of the target (frames) | 28 | 26 | 17 | 40 | 1706.0 | 94.8 | 213.28 |
| Successfully tracked (s) | 42.81 | 41.09 | 40.96 | 38.18 | 722.27 | 40.13 | 5.86 |
| Lost track of the target (s) | 1.25 | 1.07 | 0.75 | 1.68 | 74.85 | 4.16 | 9.57 |
| Lost track of the target | 2.8 | 2.5 | 1.8 | 4.2 | - | 8.02 | 0.16 |
| Successful tracking rate (%) | 97.2 | 97.5 | 98.2 | 95.8 | - | 91.98 | 0.16 |
| Computation time (fps) | 22.33 | 24.41 | 22.53 | 23.78 | - | 23.34 | 0.85 |
std: standard deviation, fps: Frame per Second.