
Figure 1.
Overview of the industrial robot vision system

Figure 2.
Illustration of industrial robot vision system: the green point is the initialized estimate center point, and the red point is the actual center point

Figure 3.
A block diagram of our proposed calibration method. The translation vector between the initialized estimate center point (green point), and the calibration center point (red point) is calculated based on deep learning, and our novel calibration method

Figure 4.
The progress of the calculation of the object position in the real-world coordinate

Figure 5.
The progress of object segmentation and edge extraction

Figure 6.
Illustration of the estimated translation vector
Table 1.
Experiment setup details
| Parameter Spec | Spec |
|---|---|
| Process | Intel Xeon Processor with two cores @ 2.3 GHz |
| GPU | NVIDIA Tesla T4 |
| RAM | 13 GB |
| OS | Ubuntu 20.04 LTS |

Figure 7.
Visualized examples of experimental results: figure (b): the orange point is the Yolo center, figure (d): dark red is the upper part center. The vector created by the blue points is a translation vector; the light blue point is the correction center
Table 3.
Experimental results evaluate the position error of our algorithm (mm)
| Fold | Sample | Traditional Method | Regression Method [30] | Proposed Method | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Δx | Δy | Err | Δx | Δy | Err | Δx | Δy | Err | Δx | Δy | Err | ||
| 1 | 1 | 9.69 | 5.51 | 11.15 | 1.34 | 1.32 | 1.88 | 0.38 | 1.14 | 1.20 | 0.95 | 0.76 | 1.22 |
| 2 | 8.36 | 8.74 | 12.09 | 1.92 | 2.50 | 3.15 | 3.04 | 1.33 | 3.32 | 1.71 | 1.33 | 2.17 | |
| 3 | 5.13 | 8.93 | 10.30 | 1.23 | 1.52 | 1.96 | 1.14 | 0.95 | 1.48 | 1.14 | 0.95 | 1.48 | |
| 4 | 10.07 | 8.36 | 13.09 | 1.79 | 1.97 | 2.66 | 1.14 | 1.33 | 1.75 | 1.52 | 1.33 | 2.02 | |
| 5 | 8.55 | 10.26 | 13.36 | 0.75 | 1.12 | 1.35 | 0.76 | 0.19 | 0.78 | 0.38 | 0.57 | 0.69 | |
| 6 | 9.31 | 9.31 | 13.17 | 0.96 | 1.41 | 1.71 | 0.19 | 1.52 | 1.53 | 0.57 | 0.76 | 0.95 | |
| 2 | 1 | 4.18 | 5.89 | 7.22 | 1.45 | 3.07 | 3.40 | 1.33 | 2.09 | 2.48 | 0.95 | 1.14 | 1.48 |
| 2 | 10.07 | 13.11 | 16.53 | 3.12 | 3.41 | 4.62 | 2.47 | 1.71 | 3.00 | 2.47 | 1.33 | 2.81 | |
| 3 | 3.42 | 7.03 | 7.82 | 1.21 | 2.78 | 3.03 | 1.52 | 1.90 | 2.43 | 0.76 | 0.57 | 0.95 | |
| 4 | 10.07 | 8.74 | 13.33 | 2.13 | 1.51 | 2.61 | 0.95 | 0.19 | 0.97 | 1.90 | 0.95 | 2.12 | |
| 5 | 11.02 | 12.16 | 16.41 | 2.94 | 2.67 | 3.97 | 2.28 | 1.71 | 2.85 | 2.47 | 0.57 | 2.53 | |
| 6 | 8.93 | 11.02 | 14.18 | 0.43 | 1.34 | 1.41 | 1.33 | 0.38 | 1.38 | 0.19 | 0.19 | 0.27 | |
| 3 | 1 | 9.12 | 7.60 | 11.87 | 1.39 | 1.42 | 1.99 | 0.95 | 0.19 | 0.97 | 1.14 | 0.38 | 1.20 |
| 2 | 4.18 | 13.87 | 14.49 | 2.54 | 3.36 | 4.21 | 3.23 | 0.19 | 3.24 | 2.28 | 0.57 | 2.35 | |
| 3 | 9.88 | 4.18 | 10.73 | 0.76 | 1.12 | 1.35 | 0.57 | 0.76 | 0.95 | 0.57 | 0.76 | 0.95 | |
| 4 | 7.60 | 8.93 | 11.73 | 1.89 | 2.17 | 2.88 | 1.71 | 0.95 | 1.96 | 1.71 | 0.95 | 1.96 | |
| 5 | 10.45 | 4.94 | 11.56 | 0.88 | 2.34 | 2.50 | 1.71 | 1.52 | 2.29 | 0.57 | 0.76 | 0.95 | |
| 6 | 6.08 | 7.60 | 9.73 | 0.36 | 0.57 | 0.67 | 0.19 | 0.57 | 0.60 | 0.19 | 0.57 | 0.60 | |
| 4 | 1 | 13.87 | 10.26 | 17.25 | 1.37 | 2.84 | 3.15 | 0.76 | 2.47 | 2.58 | 0.95 | 2.09 | 2.30 |
| 2 | 11.97 | 7.98 | 14.39 | 2.84 | 1.45 | 3.19 | 2.28 | 1.33 | 2.64 | 2.28 | 1.33 | 2.64 | |
| 3 | 5.32 | 4.56 | 7.01 | 0.35 | 0.81 | 0.88 | 0.19 | 0.38 | 0.42 | 0.19 | 0.57 | 0.60 | |
| 4 | 5.51 | 16.34 | 17.24 | 0.32 | 1.32 | 1.36 | 0.76 | 1.14 | 1.37 | 0.19 | 1.71 | 1.72 | |
| 5 | 10.26 | 8.36 | 13.23 | 0.92 | 0.92 | 1.30 | 2.28 | 0.76 | 2.40 | 0.57 | 1.14 | 1.27 | |
| 6 | 6.27 | 11.40 | 13.01 | 1.47 | 1.63 | 2.19 | 1.90 | 2.85 | 3.43 | 1.33 | 1.33 | 1.88 | |
| Average | 8.30 | 8.96 | 12.54 | 1.43 | 1.86 | 2.34 | 1.38 | 1.15 | 1.92 | 1.12 | 0.94 | 1.55 | |
