| Interactive tracking of movable objects for the blind on the basis of environment models and perception-oriented object recognit Recent countries visiting this post |  |
 | 7 | United States |
 | 3 | |
 | 2 | China |
 | 1 | Germany |
| Interactive tracking of movable objects for the blind on the basis of environment models and perception-oriented object recognit Recent countries visiting this post | |
| 7 | United States |
| 3 | |
| 2 | China |
| 1 | Germany |