1. HIGH-SPEED LASER LOCALIZATION FOR MOBILE ROBOTS - Kai Lingemann, Andreas Nuchter -Robotics and Autonomous Systems (2005)

2. OBJECT IN PAPER Previous localization method Point-wise scan matching Histogram matching Using feature (extracted line, landmark) Drawback of previous approach in high speed (4m/s = 14.4km/h) Low precision High computational cost

3. GENERAL SCAN MATCHING HAYAI (high-speed and yet accurate indoor/outdoor tracking) Fast filtering (step 1) Closed form solution for computing the pose shift (step3) Algorithm

4. HAYAI (HIGH-SPEED AND YET ACCURATE INDOOR/OUTDOOR TRACKING) Algorithm Flow Data filtering Extraction and matching of features Pose calculation Data filtering Remove salt-and-pepper nose by median filter |med val – cur val| > thresh(δ) → cur val = med val; (δ = 200 cm)

5. HAYAI (HIGH-SPEED AND YET ACCURATE INDOOR/OUTDOOR TRACKING) Extraction feature Sharpen the data by [-1, 4, -1] mask Compute derivation by [-0.5, 0, 0.5] mask Smooth gradient by [1, 1, 1] mask Find zero crossing (it is a feature)

6. HAYAI (HIGH-SPEED AND YET ACCURATE INDOOR/OUTDOOR TRACKING) Matching feature Matching reference feature M and current feature D Output is

7. HAYAI (HIGH-SPEED AND YET ACCURATE INDOOR/OUTDOOR TRACKING)

8. Pose calculation Pn Pn+1 ∆x ∆y∆y θ θ

12. HAYAI (HIGH-SPEED AND YET ACCURATE INDOOR/OUTDOOR TRACKING)

13. Reference map 70 scan/sec 10 scan/sec

14. FUTURE WORK Finding zero crossing Make map