Table 1.
Configuration of the Stereo Vision System
Items | Parameters | Value |
Left and right camera | Camera Resolution | PointGray BFLY-50A2M
pixel |
Frame Rate | 13 fps |
Sensor Type | CMOS |
Sensor Size
|
|
Pixel Size |
|
Focal Length | 6 mm |
Structural parameters | Distance
| 300 mm |
Angle
| 16° |
Table 2.
Intrinsic Parameters and Errors of the Cameras
Intrinsic Parameters | Left Camera | Right Camera |
| [3780.39161; 3786.66161] | [3762.52812; 3770.94509] |
| [4.95396; 4.03090] | [4.45253; 4.26426] |
cc
| [1335.89287; 838.41230] | [1260.04705; 795.17519] |
| [3.85301; 6.56333] | [3.49159; 5.5482] |
| [−0.12175; 0.18301; 0; −0.00695; 0.00201] | [−0.08015; −0.04991;0; −0.00830; −0.0004] |
| [0.01369; 0.13495; 0;0.00107; 0.00090] | [0.01123; 0.07463; 0; 0.00100; 0.00102] |
Table 3.
Structural Parameters and Errors of the Cameras
Structural Parameters |
|
|
|
|
|
|
|
|
Table 4.
Distance between the Feature Point and the Epipolar Line (Unit: Pixel)
Feature Points |
|
|
|
|
|
|
|
|
|
|
|
| 58.463 | 147.261 | 103.319 | 6.068 | 103.977 | 51.587 | 56.109 | 103.613 | 42.150 | 145.363 | 189.523 |
| 116.220 | 205.333 | 46.140 | 63.638 | 46.801 | 109.318 |
1.239
| 46.435 | 15.248 | 88.335 | 132.652 |
| 165.323 | 254.706 |
2.473
| 112.582 |
1.810
| 158.401 | 49.995 |
2.177
| 64.046 | 39.850 | 84.302 |
| 8.389 | 96.913 | 152.893 | 43.844 | 153.549 |
1.534
| 105.829 | 153.186 | 91.913 | 194.806 | 238.829 |
| 25.909 | 62.427 | 186.848 | 78.031 | 187.503 | 32.750 | 139.884 | 187.140 | 125.998 | 228.673 | 272.601 |
| 164.285 | 253.662 |
1.445
| 111.548 |
0.782
| 157.363 | 48.964 |
1.149
| 63.015 | 40.875 | 85.324 |
| 149.204 | 237.713 | 12.056 | 96.978 | 12.712 | 142.349 | 35.002 | 12.348 | 48.916 | 53.964 | 97.982 |
| 206.176 | 295.007 | 44.329 | 153.761 | 43.671 | 199.297 | 91.559 | 44.035 | 105.524 |
2.267
| 41.911 |
| 251.130 | 340.215 | 88.819 | 198.565 | 88.159 | 244.231 | 136.184 | 88.524 | 150.189 | 46.637 |
2.331
|
| 102.041 | 190.284 | 58.732 | 49.973 | 59.386 | 95.207 | 11.816 | 59.024 |
2.056
| 100.514 | 144.398 |
| 102.655 | 190.902 | 58.123 | 50.585 | 58.778 | 95.822 | 11.206 | 58.415 |
2.667
| 99.907 | 143.793 |
| 13.162 | 102.599 | 149.785 | 39.610 | 150.448 | 6.236 | 102.235 | 150.081 | 88.175 | 192.132 | 236.609 |
| 167.314 | 256.689 | 4.476 | 114.577 | 3.813 | 160.392 | 51.994 | 4.180 | 66.045 | 37.844 | 82.292 |
Table 5.
Gray Value Correlation of the Small Window Centered on the Feature Points
Feature Points |
|
|
|
|
|
|
|
|
|
|
|
| 0.014 | 0.527 | 0.287 | 0.384 | 0.287 | 0.593 | 0.169 | 0.403 | 0.368 | 0.434 | −0.829 |
| −0.404 | 0.699 | 0.160 | −0.316 | 0.160 | 0.764 |
0.964
| 0.140 | −0.560 | −0.502 | −0.362 |
| −0.677 | 0.632 |
0.867
| −0.421 |
0.867
| 0.282 | 0.366 |
0.874
| −0.158 | −0.062 | −0.609 |
| −0.043 | 0.686 | −0.063 | 0.205 | −0.063 |
0.980
| 0.751 | −0.007 | −0.032 | 0.014 | −0.689 |
| −0.831 | 0.176 | 0.372 | −0.965 | 0.372 | −0.134 | 0.368 | 0.237 | −0.684 | −0.636 | 0.246 |
| −0.784 | 0.678 |
0.815
| −0.549 |
0.815
| 0.352 | 0.460 |
0.766
| −0.228 | −0.112 | −0.615 |
| 0.114 | −0.574 | −0.373 | −0.198 | −0.373 | −0.680 | −0.338 | −0.425 | −0.375 | −0.421 | 0.957 |
| 0.534 | −0.389 | −0.272 | 0.599 | −0.272 | −0.243 | −0.637 | −0.210 | 0.894 |
0.944
| −0.194 |
| 0.163 | −0.631 | −0.440 | −0.137 | −0.440 | −0.695 | −0.398 | −0.475 | −0.333 | −0.386 |
0.978
|
| 0.562 | −0.393 | −0.211 | 0.631 | −0.211 | −0.205 | −0.626 | −0.146 |
0.955
| 0.956 | −0.271 |
| 0.593 | −0.524 | −0.257 | 0.665 | −0.257 | −0.383 | −0.810 | −0.194 |
0.871
| 0.843 | −0.038 |
| 0.811 | −0.171 | −0.463 | 0.954 | −0.463 | 0.181 | −0.368 | −0.320 | 0.670 | 0.619 | −0.240 |
| −0.690 | 0.297 | 0.762 | −0.795 | 0.762 | −0.095 | 0.380 | 0.621 | −0.450 | −0.420 | −0.093 |
Table 6.
3D Coordinates Calculated by the Feature Points in the Left and Right Cameras
Feature Points | PCS1/Pixel | PCS2/Pixel | CCS1/mm |
|
|
|
|
|
|
|
3 | 1459 | 945.7 | 890.4 | 926.1 | 32.971 | 28.571 | 1011.747 |
5 | 1106 | 826.3 | 562.2 | 801.8 | –58.752 | –3.409 | 964.583 |
6 | 1188 | 915.2 | 659.6 | 895.5 | –36.843 | 19.101 | 940.316 |
9 | 1285 | 734.7 | 732.7 | 711.8 | –13.248 | –27.277 | 983.939 |
10 | 1371 | 820 | 831.5 | 800.1 | 8.911 | –4.826 | 959.825 |
11 | 1451 | 778.4 | 905.6 | 757.6 | 29.470 | –15.738 | 968.530 |
12 | 1362 | 693 | 804.7 | 673.7 | 6.847 | –38.124 | 993.102 |
Table 7.
Error Analysis of Binocular Vision Measurement
Distance Point Num. | Binocular Vision Measurement (mm) | Designed Dimension (mm) | Error (mm) |
| 39.6931 | 40.00 | −0.3069 |
| 80.0454 | 80.00 | 0.0454 |
| 55.1954 | 55.00 | 0.1954 |
| 54.9088 | 55.00 | −0.0912 |
| 79.5089 | 80.00 | −0.4911 |
| 39.7049 | 40.00 | −0.2951 |
| 24.8504 | 25.00 | −0.1496 |
| 24.6050 | 25.00 | −0.3950 |
| 40.2083 | 40.00 | 0.2083 |
Table 8.
3D Coordinates of the Feature Points in Workpieces with Different Positions and Postures
Num. | Position 1 CCS1 (mm) | Position 2 CCS1 (mm) | Position 3 CCS1 (mm) |
1 | — | — | — |
2 | — | (−39.65, 247.99, 825.71) | (182.32, 124.57, 990.48) |
3 | (32.97, 28.57, 1011.75) | (34.43, 250.76, 856.17) | — |
4 | — | — | — |
5 | (−58.75, −3.41, 964.58) | (−39.93, 176.14, 832.85) | (161.13, 57.47, 974.43) |
6 | (−36.84, 19.10, 940.31) | (−27.10, 194.92, 800.41) | (178.23, 82.47, 947.60) |
7 | — | (−3.44, 195.73, 809.71) | — |
8 | — | (−16.65, 177.11, 842.42) | — |
9 | (−13.25, −27.28, 983.94) | (10.88, 178.30, 854.12) | (210.54, 38.29, 988.45) |
10 | (8.91, −4.83, 959.83) | (24.07, 196.90, 821.00) | (227.36, 63.18, 962.41) |
11 | (29.47, −15.74, 968.53) | (46.94, 197.90, 830.84) | (249.93, 54.31, 969.03) |
12 | (6.85, −38.12, 993.10) | (34.28, 179.26, 863.76) | (232.97, 29.48, 994.71) |
Table 9.
Position and Pose of the Workpiece Calculated at Different Positions
| Position Under Camera Coordinate System CCS1 (mm) | Pose Under Camera Coordinate System CCS1 (rad) |
Position 1 | (−55.61, 38.83, 1006.76) | (2.1489, 1.1138, −0.5335) |
Position 2 | (−51.91, 229.20, 858.75) | (1.5900, 1.3001, −0.5713) |
Position 3 | (165.41, 99.91, 1017.05) | (2.0898, 1.2731, −0.6076) |
Table 10.
Estimation of the Position and the Pose for the Automobile Die
Position | Position Under Camera Coordinate System CCS1 (mm) | Pose Under Camera Coordinate System CCS1 (rad) |
1 | (214.16, 52.50, 1166.33) | (−0.1270, 0.1323, −0.4248) |
2 | (76.47, 114.16, 1243.56) | (−0.7560, −0.2725, −2.8310) |
3 | (259.71, 329.41, 1025.58) | (1.1323, 0.9386, 2.2061) |
4 | (195.57, 260.69, 1141.82) | (−0.2014, −0.9096, −1.5856) |