Obstacle detection for an autonomous model car …...a stereo vision based real-time obstacle...

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Transcript of Obstacle detection for an autonomous model car …...a stereo vision based real-time obstacle...

Page 1: Obstacle detection for an autonomous model car …...a stereo vision based real-time obstacle detection system for an autonomous model car on the scale of 1:10 built for the annual

❇❛❝❤❡❧♦r ❚❤❡s✐s

❖❜st❛❝❧❡ ❞❡t❡❝t✐♦♥

❢♦r ❛♥ ❛✉t♦♥♦♠♦✉s ♠♦❞❡❧ ❝❛r

✉s✐♥❣ st❡r❡♦ ✈✐s✐♦♥

❋r❡✐❡ ❯♥✐✈❡rs✐tät ❇❡r❧✐♥

❋❛❝❤❜❡r❡✐❝❤ ■♥❢♦r♠❛t✐❦

❆r❜❡✐ts❣r✉♣♣❡ ❑ü♥st❧✐❝❤❡ ■♥t❡❧❧✐❣❡♥③

❜②

❏❛♥♥✐s ■❤r✐❣

❙✉♣❡r✈✐s♦rs✿

Pr♦❢✳ ❉r✳ ❘❛ú❧ ❘♦❥❛s✱

❉r✳ ❉❛♥✐❡❧ ●ö❤r✐♥❣

❇❡r❧✐♥

❉❡❝❡♠❜❡r ✷✵✶✹

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❊✐❞❡sst❛tt❧✐❝❤❡ ❊r❦❧är✉♥❣

■❝❤ ✈❡rs✐❝❤❡r❡ ❤✐❡r♠✐t ❛♥ ❊✐❞❡s st❛tt✱ ❞❛ss ❞✐❡s❡ ❆r❜❡✐t ✈♦♥ ♥✐❡♠❛♥❞ ❛♥❞❡✲

r❡♠ ❛❧s ♠❡✐♥❡r P❡rs♦♥ ✈❡r❢❛sst ✇♦r❞❡♥ ✐st✳ ❆❧❧❡ ✈❡r✇❡♥❞❡t❡♥ ❍✐❧❢s♠✐tt❡❧ ✇✐❡

❇❡r✐❝❤t❡✱ ❇ü❝❤❡r✱ ■♥t❡r♥❡ts❡✐t❡♥ ♦❞❡r ä❤♥❧✐❝❤❡s s✐♥❞ ✐♠ ▲✐t❡r❛t✉r✈❡r③❡✐❝❤♥✐s

❛♥❣❡❣❡❜❡♥✱ ❩✐t❛t❡ ❛✉s ❢r❡♠❞❡♥ ❆r❜❡✐t❡♥ s✐♥❞ ❛❧s s♦❧❝❤❡ ❦❡♥♥t❧✐❝❤ ❣❡♠❛❝❤t✳ ❉✐❡

❆r❜❡✐t ✇✉r❞❡ ❜✐s❤❡r ✐♥ ❣❧❡✐❝❤❡r ♦❞❡r ä❤♥❧✐❝❤❡r ❋♦r♠ ❦❡✐♥❡r ❛♥❞❡r❡♥ Prü❢✉♥❣s✲

❦♦♠♠✐ss✐♦♥ ✈♦r❣❡❧❡❣t ✉♥❞ ❛✉❝❤ ♥✐❝❤t ✈❡rö✛❡♥t❧✐❝❤t✳

❇❡r❧✐♥✱ ✷✸✳ ❉❡③❡♠❜❡r ✷✵✶✹

❏❛♥♥✐s ■❤r✐❣

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❆❜str❛❝t

❆✉t♦♥♦♠♦✉s ❝❛rs ❛r❡ ♠♦❜✐❧❡ r♦❜♦ts t❤❛t ♥❛✈✐❣❛t❡ t❤r♦✉❣❤ ❤✐❣❤❧② ✉♥♣r❡❞✐❝t❛❜❧❡

❡♥✈✐r♦♥♠❡♥ts s✉❝❤ ❛s ❝✐t② tr❛✣❝✳ ❖❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ✐s ♦♥❡ ♦❢ t❤❡ ❢✉♥❞❛♠❡♥t❛❧

t❛s❦s t❤❡② ❤❛✈❡ t♦ ❜❡ ❝❛♣❛❜❧❡ ♦❢✳ ❚❤✐s ✇♦r❦ ❞❡s❝r✐❜❡s t❤❡ ✐♠♣❧❡♠❡♥t❛t✐♦♥ ♦❢

❛ st❡r❡♦ ✈✐s✐♦♥ ❜❛s❡❞ r❡❛❧✲t✐♠❡ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ s②st❡♠ ❢♦r ❛♥ ❛✉t♦♥♦♠♦✉s

♠♦❞❡❧ ❝❛r ♦♥ t❤❡ s❝❛❧❡ ♦❢ ✶✿✶✵ ❜✉✐❧t ❢♦r t❤❡ ❛♥♥✉❛❧ ❈❛r♦❧♦✲❈✉♣ ❝♦♥t❡st✳ ❋✐rst✱

❛ ♠♦❞❡r♥ st❡r❡♦ ❝❛♠❡r❛ ✐s ✐♥tr♦❞✉❝❡❞ t♦ t❤❡ ❡①✐st✐♥❣ ♣❧❛t❢♦r♠✳ ❚❤❡ ♣r♦✈✐❞❡❞

❞❡♣t❤ ✐♥❢♦r♠❛t✐♦♥ s❡r✈❡ ❛s t❤❡ ❜❛s✐s ❢♦r ❛♥ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ❛❧❣♦r✐t❤♠ t❤❛t

✐s ❛❞❛♣t❡❞ t♦ t❤❡ ♠♦❞❡❧ ❝❛r✬s r❡❞✉❝❡❞ ❡♥✈✐r♦♥♠❡♥t✳ ❲❤✐t❡ ❝❛r❞❜♦❛r❞ ❜♦①❡s

♣❧❛❝❡❞ ♦♥ ❛ ❝✐r❝✉❧❛r tr❛❝❦ ❤❛✈❡ t♦ ❜❡ ❞❡t❡❝t❡❞ ❛s ♦❜st❛❝❧❡s t♦ ❡♥❛❜❧❡ t❤❡ ❝❛r t♦

♥❛✈✐❣❛t❡ ❛r♦✉♥❞ t❤❡♠✳ ❚❤❡ ❛❧❣♦r✐t❤♠ ❞❡t❡❝ts ❡❧❡✈❛t✐♦♥s ❛❜♦✈❡ t❤❡ ❣r♦✉♥❞ ❛s

✇❡❧❧ ❛s t❤❡ ❞✐st❛♥❝❡ ❛♥❞ ✇✐❞t❤ ♦❢ t❤❡s❡ ♦❜st❛❝❧❡s✱ ❛♥❞ ♠♦❞❡❧s t❤❡♠ ❛s ❛ ❜✐r❞✬s

❡②❡ ✈✐❡✇ ♦❢ t❤❡ ❝❛r✬s s✉rr♦✉♥❞✐♥❣s✳ ❆ s♣❡❝✐❛❧ ❢♦❝✉s ✐s ♣❧❛❝❡❞ ♦♥ t❤❡ ♦❜st❛❝❧❡

❞❡t❡❝t✐♦♥ s②st❡♠✬s r✉♥t✐♠❡✱ ❛s t❤❡ ❝❛rs ♠❛✐♥ ♣r♦❝❡ss♦r ♦♥❧② ♣r♦✈✐❞❡s ❧✐♠✐t❡❞

❝♦♠♣✉t❛t✐♦♥❛❧ ♣♦✇❡r✳ ❚❤❡ ❛❧❣♦r✐t❤♠ ♠❛❦❡s ❤❡❛✈② ✉s❡ ♦❢ ✐♥t❡❣r❛❧ ✐♠❛❣❡s ❛♥❞

s♣❡❝✐❛❧✐③❡❞ ✐♠❛❣❡ ♣②r❛♠✐❞s t♦ ❡♥❛❜❧❡ ❡①❡❝✉t✐♦♥ ✇✐t❤ ✷✵ ❍③ ❛♥❞ ♠♦r❡✳

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❈♦♥t❡♥ts

✶ ■♥tr♦❞✉❝t✐♦♥ ✶

✶✳✶ ❈❛r♦❧♦✲❈✉♣ ❛♥❞ ❇❡r❧✐♥ ❯♥✐t❡❞ ❘❛❝✐♥❣ ❚❡❛♠ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✶

✶✳✶✳✶ ❚❤❡ ❈❛r♦❧♦✲❈✉♣ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✶

✶✳✶✳✷ ❇❡r❧✐♥ ❯♥✐t❡❞ ❘❛❝✐♥❣ ❚❡❛♠ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✷

✶✳✷ ❖✈❡r✈✐❡✇✿ r❡❝♦♥str✉❝t✐♦♥ ♦❢ s✉rr♦✉♥❞✐♥❣s ❛♥❞ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ✸

✶✳✸ Pr♦❜❧❡♠ ❞❡s❝r✐♣t✐♦♥ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✹

✷ ❇❛❝❦❣r♦✉♥❞ ✺

✷✳✶ ❈❛♠❡r❛ ♠♦❞❡❧ ❛♥❞ ❜❛s✐❝ ♣r♦❥❡❝t✐✈❡ ❣❡♦♠❡tr② ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✻

✷✳✷ ❙t❡r❡♦ ✈✐s✐♦♥ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✼

✷✳✷✳✶ ❊♣✐♣♦❧❛r ❣❡♦♠❡tr② ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✽

✷✳✷✳✷ ❈❛❧✐❜r❛t❡❞ st❡r❡♦ ✈✐s✐♦♥ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✾

✷✳✷✳✸ Pr♦♣❡rt✐❡s ♦❢ ❞✐s♣❛r✐t② ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✶✵

✷✳✷✳✹ ❘❡♣r♦❥❡❝t✐♦♥ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✶✶

✷✳✸ ■♥t❡❣r❛❧ ✐♠❛❣❡s ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✶✷

✷✳✹ ❙❝❛❧❡ ❛♥❞ ✐♠❛❣❡ ♣②r❛♠✐❞s ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✶✸

✸ ❚❤❡ P❧❛t❢♦r♠ ✶✺

✸✳✶ ❋♦r♠❡r P❧❛t❢♦r♠ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✶✺

✸✳✷ ■♥tr♦❞✉❝❡❞ ❈❤❛♥❣❡s ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✶✻

✸✳✷✳✶ ❙t❡r❡♦ ❝❛♠❡r❛ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✶✻

✸✳✷✳✷ ❉❡♣❡♥❞❡♥t ❝❤❛♥❣❡s ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✶✼

✹ ❖❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ✶✽

✹✳✶ ❈r❡❛t✐♦♥ ♦❢ t❤❡ ❣r♦✉♥❞ ♠♦❞❡❧ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✶✾

✹✳✷ ❉❡t❡❝t✐♥❣ ♦❜st❛❝❧❡ r❡❣✐♦♥s ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✷✵

✹✳✷✳✶ ❉❡t❡❝t✐♥❣ ❡❧❡✈❛t❡❞ r❡❣✐♦♥s ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✷✷

✹✳✷✳✷ ❆♣♣r♦①✐♠❛t✐♥❣ t❤❡ s✉r❢❛❝❡ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✷✸

✹✳✷✳✸ ▼❡r❣✐♥❣ ❝❡❧❧s ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✷✹

✹✳✸ Pr♦❥❡❝t✐♦♥ ♦❢ ♦❜st❛❝❧❡ ❛r❡❛s ✐♥t♦ r❡❧❛t✐✈❡ ❝♦♦r❞✐♥❛t❡s ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✷✻

✺ ❊✈❛❧✉❛t✐♦♥ ✷✼

✺✳✶ ●❡♥❡r❛❧ t❡st s❡t✉♣ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✷✽

✺✳✷ ❊①♣❡r✐♠❡♥t ✶✿ ❉❡t❡❝t✐♦♥ r❛t❡ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✷✾

✺✳✸ ❊①♣❡r✐♠❡♥t ✷✿ ▼❡❛s✉r❡❞ ❞✐st❛♥❝❡s ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✸✵

✺✳✹ ❊①♣❡r✐♠❡♥t ✸✿ ❲✐❞t❤ ❛♥❞ ❤♦r✐③♦♥t❛❧ ❞✐s♣❧❛❝❡♠❡♥t ♦❢ ❞❡t❡❝t❡❞

♦❜st❛❝❧❡ ❢r♦♥ts ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✸✷

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✺✳✺ ❊①♣❡r✐♠❡♥t ✹✿ ❘✉♥t✐♠❡ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✳ ✸✹

✻ ❈♦♥❝❧✉s✐♦♥ ❛♥❞ ❢✉t✉r❡ ✇♦r❦ ✸✺

■❱

Page 6: Obstacle detection for an autonomous model car …...a stereo vision based real-time obstacle detection system for an autonomous model car on the scale of 1:10 built for the annual

✶ ■♥tr♦❞✉❝t✐♦♥ ❏❛♥♥✐s ■❤r✐❣

✶ ■♥tr♦❞✉❝t✐♦♥

■♥ t❤❡ ❧❛st ②❡❛rs✱ ❛✉t♦♥♦♠♦✉s ❝❛rs ❤❛✈❡ ❜❡❝♦♠❡ ❛♥ ✐♥❝r❡❛s✐♥❣❧② s✉❜st❛♥t✐❛❧

♣❛rt ✐♥ ❛ ✈✐s✐♦♥ ♦❢ ❢✉t✉r❡ tr❛♥s♣♦rt❛t✐♦♥ ❛♥❞ ❝✐t② tr❛✣❝✳ Pr♦❜❛❜❧② ♦♥❡ ❜✐❣

❢❛❝t♦r ❢♦r ❞r✐✈✐♥❣ t❤✐s ✐♥❝r❡❛s❡ ✇❛s t❤❡ ❉❆❘P❆ ❯r❜❛♥ ❈❤❛❧❧❡♥❣❡ ❤❡❧❞ ✐♥ ✷✵✵✼✱

❛s ✐t r❡q✉✐r❡❞ t♦ ❜✉✐❧❞ ❛♥ ❛✉t♦♥♦♠♦✉s ❝❛r t❤❛t ✇❛s ❛❜❧❡ t♦ ♥❛✈✐❣❛t❡ t❤♦✉❣❤

✉r❜❛♥ tr❛✣❝ s✐t✉❛t✐♦♥s ❬✷❪✳

❚❤❡ ❈❛r♦❧♦✲❈✉♣ ✐s ❛ ❝♦♥t❡st t❤❛t tr✐❡s t♦ tr❛♥s❢❡r t❤❡ ❡ss❡♥❝❡ ♦❢ t❤❡ ❉❆❘P❆

❯r❜❛♥ ❈❤❛❧❧❡♥❣❡ t♦ ❛ r❡❞✉❝❡❞ ❡♥✈✐r♦♥♠❡♥t ✇✐t❤ s✐♠✐❧❛r t❛s❦s t♦ ♣❡r❢♦r♠✳

❲✐t❤ t❤✐s✱ ♣❛rt✐❝✐♣❛t✐♥❣ t❡❛♠s ♦❢ st✉❞❡♥ts ❝❛♥ ❣❛✐♥ ❡①♣❡r✐❡♥❝❡ ❜② ❜✉✐❧❞✐♥❣

❛♥❞ ♣r♦❣r❛♠♠✐♥❣ ❛✉t♦♥♦♠♦✉s ♠♦❞❡❧ ❝❛rs ❛♥❞ ❝♦♠♣❡t✐♥❣ ❛❣❛✐♥st ♦t❤❡r t❡❛♠s

✐♥ t❤❡ ❝♦♥t❡st✳ ❚❤❡ ❇❡r❧✐♥ ❯♥✐t❡❞ ❘❛❝✐♥❣ ❚❡❛♠ ♣❛rt✐❝✐♣❛t❡s ✐♥ t❤❡ ❝♦♥t❡st

s✐♥❝❡ ✷✵✵✾✳

❚❤✐s ✇♦r❦ ❛✐♠s ❛t ❡①t❡♥❞✐♥❣ t❤❡ t❡❛♠s ❡①✐st✐♥❣ ♣❧❛t❢♦r♠ ✇✐t❤ ♦❜st❛❝❧❡ ❞❡t❡❝✲

t✐♦♥ ❝❛♣❛❜✐❧✐t✐❡s✳ ❆s ❛ s♦❧✉t✐♦♥✱ ✐t ✇✐❧❧ ✐♥t❡❣r❛t❡ ❛ ♠♦❞❡r♥ st❡r❡♦ ❝❛♠❡r❛ ✇✐t❤

t❤❡ ❛❧r❡❛❞② ❡①✐st✐♥❣ ❤❛r❞✇❛r❡ ❛♥❞ ♣r❡s❡♥t ❛♥❞ ❡✈❛❧✉❛t❡ ❛♥ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥

♠❡t❤♦❞ ❛❞❥✉st❡❞ t♦ t❤❡ ❈❛r♦❧♦✲❈✉♣ ❡♥✈✐r♦♥♠❡♥t✳

✶✳✶ ❈❛r♦❧♦✲❈✉♣ ❛♥❞ ❇❡r❧✐♥ ❯♥✐t❡❞ ❘❛❝✐♥❣ ❚❡❛♠

❚❤✐s s❡❝t✐♦♥ ✇✐❧❧ ✜rst ❣✐✈❡ ❛ s❤♦rt ♦✈❡r✈✐❡✇ ♦❢ t❤❡ ❈❛r♦❧♦✲❈✉♣ ❝♦♥t❡st ❛♥❞ ✐ts

r✉❧❡s✳ ■t t❤❡♥ ❞❡s❝r✐❜❡s t❤❡ ❝✉rr❡♥t st❛t❡ ♦❢ t❤❡ ❇❡r❧✐♥ ❯♥✐t❡❞ ❘❛❝✐♥❣ ❚❡❛♠✬s

♣❧❛t❢♦r♠ ❛♥❞ t❤❡ ♠♦t✐✈❛t✐♦♥ ❢♦r t❤✐s ✇♦r❦✳

✶✳✶✳✶ ❚❤❡ ❈❛r♦❧♦✲❈✉♣

❚❤❡ ❈❛r♦❧♦✲❈✉♣ ❛❧❧♦✇s ♦♥❧② st✉❞❡♥t t❡❛♠s t♦ ♣❛rt✐❝✐♣❛t❡ ✐♥ t❤❡ ❝♦♥t❡st✳ ❚❤❡

❝❛rs ♦♥ ❛ s❝❛❧❡ ♦❢ ✶✿✶✵ ❤❛✈❡ t♦ ❜❡ ❜✉✐❧t ❛♥❞ ♣r♦❣r❛♠♠❡❞ ❜② t❤❡ t❡❛♠ ♠❡♠❜❡rs✳

❯♥❞❡r❧②✐♥❣ ❝♦♥❝❡♣ts ❤❛✈❡ t♦ ❜❡ ❞❡✈❡❧♦♣❡❞ ❜② t❤❡ st✉❞❡♥ts ❛s ✇❡❧❧✳ ❚❤❡ t❡❛♠s

t❤❡♥ ❝♦♠♣❡t❡ ❛❣❛✐♥st ❡❛❝❤ ♦t❤❡r ✇✐t❤ t❤❡✐r ❝❛rs ✐♥ ❢♦✉r ❞✐✛❡r❡♥t ❞✐s❝✐♣❧✐♥❡s✿

• Pr❡s❡♥t✐♥❣ ❚❤❡ P❧❛t❢♦r♠

• ❉r✐✈✐♥❣ ❲✐t❤♦✉t ❖❜st❛❝❧❡s

• ❉r✐✈✐♥❣ ❲✐t❤ ❖❜st❛❝❧❡s

Page 7: Obstacle detection for an autonomous model car …...a stereo vision based real-time obstacle detection system for an autonomous model car on the scale of 1:10 built for the annual

✶ ■♥tr♦❞✉❝t✐♦♥ ❏❛♥♥✐s ■❤r✐❣

❋✐❣✉r❡ ✶✿ ❆❜❧❡ ♦♥ t❤❡ tr❛❝❦ ✐♥ ❇r❛✉♥s❝❤✇❡✐❣ ❞✉r✐♥❣ t❤❡ ❈❛r♦❧♦✲❈✉♣ ✷✵✶✸✳

• P❛r❦✐♥❣

❚❤❡ ✜rst t❛s❦ ❝❛❧❧❡❞ st❛t✐❝ ❞✐s❝✐♣❧✐♥❡ ❝♦♥s✐sts ♦❢ ❛ ✸✵ ♠✐♥✉t❡s ♣r❡s❡♥t❛t✐♦♥ ❣✐✈❡♥

❜② ♦♥❡ t❡❛♠ ♠❡♠❜❡r ✐♥ ❢r♦♥t ♦❢ t❤❡ ❝♦♥t❡st✬s ❥✉r②✳ ❚❤❡ t❛❧❦ ✐s ❥✉❞❣❡❞ ❜② t❤❡

♣r❡s❡♥t❡❞ ❝♦♥❝❡♣ts ✉s❡❞ ❢♦r ❤❛r❞✲ ❛♥❞ s♦❢t✇❛r❡ ♦❢ t❤❡ ♠♦❞❡❧ ❝❛r ❛s ✇❡❧❧ ❛s ✐ts

❝♦st ❛♥❞ ❡♥❡r❣② ❡✣❝✐❡♥❝②✳

❋♦r t❤❡ ❞②♥❛♠✐❝ ❞✐s❝✐♣❧✐♥❡s✱ t❤❡ ♠♦❞❡❧ ❝❛rs ❛r❡ s✉❝❝❡ss✐✈❡❧② ♣❧❛❝❡❞ ♦♥ ❛ ❝✐r❝✉❧❛r

tr❛❝❦ ♠❛r❦❡❞ ✐♥ ✇❤✐t❡ ♦♥ ❛ ✉♥✐❢♦r♠❧② ❜❧❛❝❦ ❛♥❞ ♣❧❛✐♥ ❣r♦✉♥❞ ♦❢ ✶✵ ♠ × ✶✵ ♠

s✐③❡✳ ❚❤❡ tr❛❝❦ ❤❛s ❛t ❧❡❛st ♦♥❡ ❝r♦ss✐♥❣ ❛♥❞ ♠✉❧t✐♣❧❡ s♣♦ts ✇❤❡r❡ ♠❛r❦✐♥❣s ♦♥

♦♥❡ ♦r ❜♦t❤ s✐❞❡s ❛r❡ ♠✐ss✐♥❣✳ ❋♦r t❤❡ ❞✐s❝✐♣❧✐♥❡s ❉r✐✈✐♥❣ ❲✐t❤♦✉t ❖❜st❛❝❧❡s

❛♥❞ ❉r✐✈✐♥❣ ❲✐t❤ ❖❜st❛❝❧❡s✱ t❤❡ ❝❛r ❤❛s t♦ tr❛✈❡❧ ❛s ♠✉❝❤ ❞✐st❛♥❝❡ ❛s ♣♦ss✐❜❧❡

✐♥ ✸ ♠✐♥✉t❡s✳ ■♥ ❉r✐✈✐♥❣ ❲✐t❤ ❖❜st❛❝❧❡s✱ ✐t ❛❞❞✐t✐♦♥❛❧❧② ❤❛s t♦ ♥❛✈✐❣❛t❡ ❛r♦✉♥❞

♦❜st❛❝❧❡s ♣❧❛❝❡❞ ♦♥ t❤❡ tr❛❝❦✳ ❋♦r P❛r❦✐♥❣✱ t❤❡ ❝❛r ✐s ♣❧❛❝❡❞ ♦♥ ❛ str❛✐❣❤t ♣❛rt

♦❢ t❤❡ tr❛❝❦ t❤❛t ✐s ❡①t❡♥❞❡❞ ✇✐t❤ ❛ ♣❛r❦✐♥❣ ❧❛♥❡ ❛t t❤❡ r✐❣❤t s✐❞❡✳ ❊♠♣t② s♣❛❝❡s

❜❡t✇❡❡♥ ♦❜st❛❝❧❡s ♠❛r❦ ♣❛r❦✐♥❣ s♣♦ts✳ ❚❤❡ ❝❛r ❤❛s t♦ ✜♥❞ ❛ ✜tt✐♥❣ ♣❛r❦✐♥❣

s♣♦t ❛♥❞ ♥❛✈✐❣❛t❡ ✐♥t♦ ✐t✳ P❡♥❛❧t✐❡s ❢♦r P❛r❦✐♥❣ ❛r❡ ❛✇❛r❞❡❞ ❢♦r t♦✉❝❤✐♥❣

❛❞❥❛❝❡♥t ♦❜st❛❝❧❡s✳ ■♥ ❛❧❧ ❞✐s❝✐♣❧✐♥❡s✱ ❞✐st❛♥❝❡ ♣❡♥❛❧t✐❡s ❛r❡ ❣✐✈❡♥ ❢♦r ❧❡❛✈✐♥❣

t❤❡ tr❛❝❦ ♦r ❝♦❧❧✐❞✐♥❣ ✇✐t❤ ♦❜st❛❝❧❡s✳ ■♥ t❤❡ ❝❛s❡ ♦❢ ❉r✐✈✐♥❣ ❲✐t❤ ❖❜st❛❝❧❡s t❤❡

t❡❛♠✬s ♠♦❞❡❧ ❝❛r ❛❧s♦ ❤❛s t♦ ❣✐✈❡ ✇❛② t♦ ❛ r❡♠♦t❡❧② ❝♦♥tr♦❧❧❡❞ ♠♦❜✐❧❡ ♦❜st❛❝❧❡

❛t ❝r♦ss✐♥❣s✳ ❋♦r ❢✉rt❤❡r ❞❡t❛✐❧s ♦❢ t❤❡ ❈❛r♦❧♦✲❈✉♣ r✉❧❡s✱ s❡❡ ❬✹❪✳

✶✳✶✳✷ ❇❡r❧✐♥ ❯♥✐t❡❞ ❘❛❝✐♥❣ ❚❡❛♠

❚❤❡ ❇❡r❧✐♥ ❯♥✐t❡❞ ❘❛❝✐♥❣ ❚❡❛♠ ✐s ❛ st✉❞❡♥t ♣r♦❥❡❝t ♦❢ t❤❡ ❋r❡✐❡ ❯♥✐✈❡rs✐tät

❇❡r❧✐♥ t❤❛t t❛❦❡s ♣❛rt ✐♥ t❤❡ ❈❛r♦❧♦✲❈✉♣ s✐♥❝❡ ✷✵✵✾✳ ❚❤❡ t❡❛♠ ❝✉rr❡♥t❧② ❤❛s

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✶ ■♥tr♦❞✉❝t✐♦♥ ❏❛♥♥✐s ■❤r✐❣

t✇♦ ♠♦❞❡❧ ❝❛rs ♥❛♠❡❞ ❆❜❧❡ ❛♥❞ ❇❛❦❡r ✇❤✐❝❤ ✇✐❧❧ ❜❡ ❞❡s❝r✐❜❡❞ ✐♥ ❞❡t❛✐❧ ✐♥

s❡❝t✐♦♥ ✸✳ ❚❤❡ ❝✉rr❡♥t ❤❛r❞✲ ❛♥❞ s♦❢t✇❛r❡ s❡t✉♣ ❛❧r❡❛❞② ✐♥❝❧✉❞❡s s♦❧✉t✐♦♥s

❢♦r ❉r✐✈✐♥❣ ❲✐t❤♦✉t ❖❜st❛❝❧❡s✱ ✇❤❡r❡❛s s♦❢t✇❛r❡ ❢♦r P❛r❦✐♥❣ ✐s ✉♥❞❡r ❞❡✈❡❧♦♣✲

♠❡♥t✳ ❆♥ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ t❤❛t ✇♦✉❧❞ ❝♦♥tr✐❜✉t❡ t♦ s♦❧✈❡ t❤❡ t❛s❦ ♦❢ ❉r✐✈✐♥❣

❲✐t❤ ❖❜st❛❝❧❡s ✐s st✐❧❧ ♠✐ss✐♥❣ ❜✉t ❛❜s♦❧✉t❡❧② ♥❡❝❡ss❛r② ❢♦r ❢✉rt❤❡r s✉❝❝❡ss❢✉❧

♣❛rt✐❝✐♣❛t✐♦♥✳ ❚❤❡r❡❢♦r❡✱ t❤❡ s❝❛❧❡ ♦❢ t❤✐s ✇♦r❦ ✇✐❧❧ ❜❡ t♦ ❡①t❡♥❞ t❤❡ ❡①✐st✐♥❣

❤❛r❞✲ ❛♥❞ s♦❢t✇❛r❡ t♦ ♣r♦✈✐❞❡ t❤❡ ❝❛♣❛❜✐❧✐t✐❡s ❢♦r ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥✳ ■t ✇✐❧❧

❜✉✐❧❞ t❤❡ ❜❛s✐s ❢♦r ❧❛t❡r s♦❢t✇❛r❡ t❤❛t ❛❧❧♦✇s t♦ tr❛❝❦ ❛♥❞ ❛✈♦✐❞ ♦❜st❛❝❧❡s✳

✶✳✷ ❖✈❡r✈✐❡✇✿ r❡❝♦♥str✉❝t✐♦♥ ♦❢ s✉rr♦✉♥❞✐♥❣s ❛♥❞ ♦❜st❛✲

❝❧❡ ❞❡t❡❝t✐♦♥

❋✐st ❛♥❞ ❢♦r❡♠♦st✱ r♦❜♦t ❡♥✈✐r♦♥♠❡♥ts ❛r❡ ✐♥❤❡r❡♥t❧② ✉♥♣r❡❞✐❝t❛❜❧❡✳

❲❤✐❧❡ t❤❡ ❞❡❣r❡❡ ♦❢ ✉♥❝❡rt❛✐♥t② ✐♥ ✇❡❧❧✲str✉❝t✉r❡❞ ❡♥✈✐r♦♥♠❡♥ts

s✉❝❤ ❛s ❛ss❡♠❜❧② ❧✐♥❡s ✐s s♠❛❧❧✱ ❡♥✈✐r♦♥♠❡♥ts s✉❝❤ ❛s ❤✐❣❤✇❛②s ❛♥❞

♣r✐✈❛t❡ ❤♦♠❡s ❛r❡ ❤✐❣❤❧② ❞②♥❛♠✐❝ ❛♥❞ ✐♥ ♠❛♥② ✇❛②s ❤✐❣❤❧② ✉♥♣r❡✲

❞✐❝t❛❜❧❡✳ ❚❤❡ ✉♥❝❡rt❛✐♥t② ✐s ♣❛rt✐❝✉❧❛r❧② ❤✐❣❤ ❢♦r r♦❜♦ts ♦♣❡r❛t✐♥❣

✐♥ t❤❡ ♣r♦①✐♠✐t② ♦❢ ♣❡♦♣❧❡✳ ❬✶✺✱ ♣✳ ✸❪

❆s st❛t❡❞ ❛❜♦✈❡✱ ❛ ♠♦❜✐❧❡ r♦❜♦t t❤❛t s❤❛r❡s ✐ts ❡♥✈✐r♦♥♠❡♥t ✇✐t❤ ❤✉♠❛♥s ❝❛♥

♥♦t ❡①❝❧✉s✐✈❡❧② r❡❧② ♦♥ ❛♥ ✐♥t❡r♥❛❧ ♠♦❞❡❧ ♦❢ t❤❡ ✇♦r❧❞ t♦ ♥❛✈✐❣❛t❡ t❤r♦✉❣❤ ✐t✳

❘❡❝♦♥str✉❝t✐♦♥ ♦❢ ✐ts s✉rr♦✉♥❞✐♥❣s ❛♥❞ ✇✐t❤ t❤✐s ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ❛r❡ ♣❛rt ♦❢

t❤❡ ❢✉♥❞❛♠❡♥t❛❧ t❛s❦s ✐t ❤❛s t♦ ❢✉❧✜❧❧✳

❆s ❝❛♠❡r❛s ♦♥❧② ♣r♦✈✐❞❡ ❧✐♠✐t❡❞ ✐♥❢♦r♠❛t✐♦♥ ❛❜♦✉t t❤❡ s♣❛t✐❛❧ str✉❝t✉r❡ ♦❢ ❛♥

❡♥✈✐r♦♥♠❡♥t✱ ♠♦❜✐❧❡ r♦❜♦ts ♦❢t❡♥ ♠❛❦❡ ✉s❡ ♦❢ ❛ ✇✐❞❡ ✈❛r✐❡t② ♦❢ s❡♥s♦rs ❛❜❧❡

t♦ s❡♥s❡ ❞❡♣t❤ s✉❝❤ ❛s ❧❛s❡r s❝❛♥♥❡rs✱ ✐♥❢r❛r❡❞✱ r❛❞❛r ❛♥❞ ✉❧tr❛s♦♥✐❝ s❡♥s♦rs✳

❉✉❡ t♦ t❤❡ r❡❝❡♥t ❞❡✈❡❧♦♣♠❡♥ts ✐♥ st❡r❡♦ ✈✐s✐♦♥✱ st❡r❡♦ ❝❛♠❡r❛s s✉❝❤ ❛s t❤❡

▼✐❝r♦s♦❢t ❑✐♥❡❝t ❛r❡ ✐♥❝r❡❛s✐♥❣❧② ❜❡✐♥❣ ✉s❡❞ ✐♥ r♦❜♦t✐❝s✳ ❙t❡r❡♦ ❝❛♠❡r❛s ❤❛✈❡

t❤❡ ❛❞✈❛♥t❛❣❡ ♦✈❡r ❡✳❣✳ ❧❛s❡r s❝❛♥♥❡rs t❤❛t t❤❡② ❣❡♥❡r❛❧❧② ♣r♦✈✐❞❡ ❤✐❣❤❡r r❡s♦✲

❧✉t✐♦♥s ❛♥❞ ♣r♦✈✐❞❡ ✐♠❛❣❡s s❤♦✇✐♥❣ t❤❡ t❡①t✉r❡s ♦❢ ✜❧♠❡❞ ♦❜❥❡❝ts ❛t t❤❡ s❛♠❡

t✐♠❡✳

■♥ ❛♣♣r♦❛❝❤❡s s✉❝❤ ❛s ❬✸❪✱ t❤❡ ❞❡♣t❤ ✐♥❢♦r♠❛t✐♦♥ ✐s ✉s❡❞ t♦ ❝r❡❛t❡ ❛ ✸❉ s❡❣♠❡♥✲

t❛t✐♦♥ ♦❢ ❛ ♠♦❜✐❧❡ r♦❜♦t✬s s✉rr♦✉♥❞✐♥❣s✳ ❆s ❛ ❣r♦✉♥❞ ♣❧❛♥❡ ✐s ❞❡t❡❝t❡❞✱ ♦❜❥❡❝ts

❧♦❝❛t❡❞ ♦♥ t❤✐s s✉r❢❛❝❡ ❝❛♥ ❜❡ ❞✐st✐♥❣✉✐s❤❡❞✳ ❬✼❪ ❝r❡❛t❡s ❛ ✸❉ r❡❝♦♥str✉❝t✐♦♥

♦❢ t❤❡ s✉rr♦✉♥❞✐♥❣s ✇✐t❤ ❛ ❞✐❝t✐♦♥❛r② ❛♥❞ ♠❛❝❤✐♥❡ ❧❡❛r♥✐♥❣ ❜❛s❡❞ ❛♣♣r♦❛❝❤

❛♥❞ ❛❧❧♦✇s ❢♦r ♦❜❥❡❝t ❞❡t❡❝t✐♦♥✳ ■t ❛❞❞✐t✐♦♥❛❧❧② ♠❛❦❡s ✉s❡ ♦❢ t❤❡ ❘●❇✲✐♠❛❣❡s

Page 9: Obstacle detection for an autonomous model car …...a stereo vision based real-time obstacle detection system for an autonomous model car on the scale of 1:10 built for the annual

✶ ■♥tr♦❞✉❝t✐♦♥ ❏❛♥♥✐s ■❤r✐❣

♣r♦✈✐❞❡❞ ❜② t❤❡ ▼✐❝r♦s♦❢t ❑✐♥❡❝t t♦ ❝♦❧♦r ❝♦♥str✉❝t❡❞ ✸❉ s✉r❢❛❝❡s✳

❋♦r t❤❡ t❛s❦ ♦❢ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥✱ ❛❧❧ ♦❜❥❡❝ts ❢♦✉♥❞ ♦♥ t❤❡ ❣r♦✉♥❞ ♠❛② ❜❡ ❝❧❛s✲

s✐✜❡❞ ❛s ♦❜st❛❝❧❡s ❛s t❤❡② ♠❛② ❤✐♥❞❡r t❤❡ r♦❜♦t ✐♥ ✐ts ♠♦✈❡♠❡♥t✳ ❆✉t♦♥♦♠♦✉s

❝❛rs ♣r❡s❡♥t ♥♦ ❡①❝❡♣t✐♦♥ ✇❤❡♥ ✐t ❝♦♠❡s t♦ t❤❡ ♥❡❝❡ss✐t② ♦❢ ❣❡tt✐♥❣ ❜❡tt❡r ✉♥✲

❞❡rst❛♥❞✐♥❣ ♦❢ s✉rr♦✉♥❞✐♥❣s ❛s t❤❡② ❛r❡ ♠♦❜✐❧❡ r♦❜♦ts ❝♦♥❢r♦♥t❡❞ ✇✐t❤ ❛ ❤✐❣❤❧②

❞②♥❛♠✐❝ ❡♥✈✐r♦♥♠❡♥t✳ ❖❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ✐s ♠♦st ❝r✉❝✐❛❧✱ ❛s ❝♦❧❧✐s✐♦♥s ✇✐t❤

♦t❤❡r tr❛✣❝ ♣❛rt✐❝✐♣❛♥ts ❛♥❞ ♣❡rs♦♥❛❧ ✐♥❥✉r② ❤❛✈❡ t♦ ❜❡ ♣r❡✈❡♥t❡❞ ✐♥ ❛♥② ❝❛s❡✳

❚❤❡r❡❢♦r❡✱ ❛✉t♦♥♦♠♦✉s ❝❛rs ❛❧s♦ ♠❛❦❡ ✐♥t❡♥s❡ ✉s❡ ♦❢ s❡♥s♦rs ❝❛♣❛❜❧❡ ♦❢ s❡♥s✐♥❣

❞❡♣t❤✱ s✉❝❤ ❛s t❤❡ ❝❛rs ❙♣✐r✐t ♦❢ ❇❡r❧✐♥ ❬✶✹❪ ❛♥❞ ❈❛r♦❧✐♥❡ ❬✶❪✱ ❬✶✼❪✳ ❇♦t❤ ❝❛rs

✇❡r❡ ❞❡✈❡❧♦♣❡❞ t♦ t❛❦❡ ♣❛rt ✐♥ t❤❡ ❉❆❘P❆ ❯r❜❛♥ ❈❤❛❧❧❡♥❣❡ ✷✵✵✼✳ ❚❤❡ ❙♣✐r✐t

♦❢ ❇❡r❧✐♥ ❛❧s♦ ❤❛s st❡r❡♦ ✈✐s✐♦♥ s②st❡♠ ✐♥st❛❧❧❡❞ ✇✐t❤ t❤❡ ❣♦❛❧ t♦ ❞❡t❡❝t str❡❡t

♠❛r❦✐♥❣s ❛♥❞ ♦t❤❡r ❝❛rs ♦♥ t❤❡ r♦❛❞✳

■♥ t❤❡ ❈❛r♦❧♦✲❈✉♣✱ r✉❧❡s ❣✐✈❡ ♠❛♥② ❣✉❛r❛♥t❡❡s r❡❣❛r❞✐♥❣ t❤❡ ❡♥✈✐r♦♥♠❡♥t✳

❚❤❡r❡❢♦r❡ ❛ r❡❝♦♥str✉❝t✐♦♥ ♦❢ t❤❡ s✉rr♦✉♥❞✐♥❣s ❛s✐❞❡ ❢r♦♠ ❧❛♥❡s ❛♥❞ ♦❜st❛❝❧❡s

✐s ♥♦t ♥❡❝❡ss❛r② ✐♥ ♠♦st s✐t✉❛t✐♦♥s✳ ❆s ♦❜st❛❝❧❡s ❛r❡ r❡♣r❡s❡♥t❡❞ t❤r♦✉❣❤ ✇❤✐t❡

❝❛r❞❜♦❛r❞ ❜♦①❡s✱ ❛ ♥❛✐✈❡ ❛♣♣r♦❛❝❤ ✇♦✉❧❞ ❜❡ t♦ ❞❡t❡❝t t❤❡s❡ ✇❤✐t❡ r❡❣✐♦♥s ♦♥

t❤❡ ✐♠❛❣❡s ♦❢ ❛ r❡❣✉❧❛r ✇❡❜❝❛♠✳ ❇✉t s✐♥❝❡ t❤✐s ✐s ❞❡♣❡♥❞❡♥t ♦♥ t❤❡ ❧✐❣❤t✐♥❣ ♦❢

t❤❡ s❝❡♥❡✱ ✐t t❡♥❞s t♦ ❜❡ ❤✐❣❤❧② ✉♥r❡❧✐❛❜❧❡✳ ❋✉rt❤❡r♠♦r❡✱ ❛ ✇❡❜❝❛♠ ✇♦✉❧❞ ❣✐✈❡

❢❡✇ ✐♥❢♦r♠❛t✐♦♥ ❛❜♦✉t t❤❡ ❞✐st❛♥❝❡ t♦ ♦❜st❛❝❧❡s ❢♦✉♥❞ ♦♥ t❤❡ tr❛❝❦✳ ❚❤✐s ✐s

✇❤② ♠❛♥② t❡❛♠s ✉s❡ t❤❡ ❝♦♠❜✐♥❛t✐♦♥ ♦❢ ❛ ❧✐♥❡ ❧❛s❡r ❛♥❞ ❛ ✇❡❜❝❛♠ t♦ ❝❛❧❝✉❧❛t❡

❞❡♣t❤ t♦ ❧✐t ♦❜st❛❝❧❡s ❬✻❪ ✈✐❛ tr✐❛♥❣✉❧❛t✐♦♥✳ ❖t❤❡r ❞❡♣t❤ s❡♥s♦rs s✉❝❤ ❛s ❛rr❛②s

♦❢ ✐♥❢r❛r❡❞ s❡♥s♦r ❛r❡ ❛❧s♦ q✉✐t❡ ❝♦♠♠♦♥✱ ❢♦r ❡①❛♠♣❧❡ ✐♥ ❬✶✸❪ ❛♥❞ ❬✶✶❪✳ ■♥ t❤❡

❝❛s❡ ♦❢ ❬✶✶❪✱ ❛❧❧ ♦❢ t❤❡s❡ s❡♥s♦rs ❛r❡ ✉s❡❞ t♦❣❡t❤❡r ✐♥ ♦♥❡ s❡t✉♣✳ ❚❤❡ ❝❛♠❡r❛

✐♠❛❣❡s ❛r❡ t❤❡♥ ♦♥❧② ❛♥❛❧②③❡❞ ✐♥ ❝❛s❡ ♦♥❡ ♦❢ t❤❡ ✐♥❢r❛r❡❞ s❡♥s♦rs ✐s tr✐❣❣❡r❡❞

❜② ❛♥ ♦❜st❛❝❧❡ t♦ ❛✈♦✐❞ ❝♦st❧② s❡❛r❝❤ ❢♦r ♦❜st❛❝❧❡s ♦♥ t❤❡ ✐♠❛❣❡ ✇❤✐❧❡ ❞r✐✈✐♥❣

♦♥ ❛ ❢r❡❡ r♦❛❞✳ ❙t❡r❡♦ ❝❛♠❡r❛s ❤❛✈❡ ♥♦t ❜❡❡♥ ✉s❡❞ ❜② ♣❛rt✐❝✐♣❛t✐♥❣ t❡❛♠s s♦

❢❛r✱ ♣r♦❜❛❜❧② ❜❡❝❛✉s❡ ❛✈❛✐❧❛❜❧❡ ❧♦✇✲❝♦st ❝❛♠❡r❛s s✉❝❤ ❛s t❤❡ ❑✐♥❡❝t ❛r❡ t♦♦

❜✐❣ t♦ ✜t ♦♥ ❛ ❝❛r t❤❛t ❤❛s t♦ ❝♦♥❢♦r♠ t♦ t❤❡ ❈❛r♦❧♦✲❈✉♣ r✉❧❡s✳

✶✳✸ Pr♦❜❧❡♠ ❞❡s❝r✐♣t✐♦♥

❋r♦♠ t❤❡ ♣❡rs♣❡❝t✐✈❡ ♦❢ ♦✉r ♠♦❞❡❧ ❝❛r✱ ❡✈❡r② ❡❧❡✈❛t✐♦♥ ❢r♦♠ t❤❡ ❣r♦✉♥❞ ❡①✲

❝❡❡❞✐♥❣ ❛ ❢❡✇ ❝❡♥t✐♠❡t❡rs r❡♣r❡s❡♥ts ❛♥ ♦❜st❛❝❧❡✳ ❲❤✐❧❡ ✐♥ t❤❡ ❝♦♥t❡①t ♦❢ t❤❡

❈❛r♦❧♦✲❈✉♣ r✉❧❡s t❤❡ ❣r♦✉♥❞ ✐ts❡❧❢ ✐s ❣✉❛r❛♥t❡❡❞ t♦ ❜❡ ❛ ♣❧❛✐♥ ❜❧❛❝❦ s✉r❢❛❝❡✱

♦❜st❛❝❧❡s ❛r❡ ♣❧❛❝❡❞ ♦♥ ❛♥❞ ❜❡s✐❞❡s t❤❡ tr❛❝❦✳ ❚❤❡② ❛r❡ r❡♣r❡s❡♥t❡❞ ❜② ✇❤✐t❡

❝❛r❞❜♦❛r❞ ❜♦①❡s ✇✐t❤ ❛ ❞❡✜♥❡❞ ✇✐❞t❤ ❛♥❞ ❤❡✐❣❤t ♦❢ ✶✵✲✹✵ ❝♠ ❛♥❞ ❛ ❧❡♥❣t❤ ♦❢

Page 10: Obstacle detection for an autonomous model car …...a stereo vision based real-time obstacle detection system for an autonomous model car on the scale of 1:10 built for the annual

✷ ❇❛❝❦❣r♦✉♥❞ ❏❛♥♥✐s ■❤r✐❣

❛t ❧❡❛st ✶✵ ❝♠✳ ❆ ♠✐♥✐♠✉♠ ❞✐st❛♥❝❡ ♦❢ ✶ ♠ ❜❡t✇❡❡♥ ♦❜st❛❝❧❡s ❣✉❛r❛♥t❡❡s ❛

♣♦ss✐❜❧❡ ♣❛t❤ ❢♦r t❤❡ ❝❛r t♦ ❛✈♦✐❞ t❤❡♠ ❛♥❞ st✐❧❧ st❛② ♦♥ t❤❡ tr❛❝❦✳ ❆❞❞✐t✐♦♥❛❧❧②✱

❛ r❡♠♦t❡ ❝♦♥tr♦❧❧❡❞ ♠♦❞❡❧ ❝❛r ❛❧s♦ ❝♦✈❡r❡❞ ✐♥ ❛ ✇❤✐t❡ ❜♦① ♣♦s❡s ❛s ❛ ♠♦❜✐❧❡

♦❜st❛❝❧❡✳ ■t ♠♦✈❡s ✇✐t❤ ❛ ♠❛①✐♠✉♠ s♣❡❡❞ ♦❢ ✵✳✻ ♠✴s ❛♥❞ r✉❧❡s ❣✉❛r❛♥t❡❡ t❤❛t

✐t ✇✐❧❧ ♦♥❧② ♦❝❝✉r ✐♥ s✐t✉❛t✐♦♥s ✇❤❡r❡ ✐t ❞♦❡s ♥♦t ❜❧♦❝❦ t❤❡ ❡♥t✐r❡ r♦❛❞✳

❉✉r✐♥❣ t❤❡ ❞✐s❝✐♣❧✐♥❡ ❉r✐✈✐♥❣ ❲✐t❤ ❖❜st❛❝❧❡s t❤❡ ♠♦❞❡❧ ❝❛r ❤❛s t♦ st❛② ♦♥

t❤❡ tr❛❝❦ ✇❤✐❧❡ ♥❛✈✐❣❛t✐♥❣ ❛r♦✉♥❞ ♦❜st❛❝❧❡s ❛♥❞ tr❛✈❡❧ ❛s ♠✉❝❤ ❞✐st❛♥❝❡s ❛s

♣♦ss✐❜❧❡✳ ❚♦ ❞♦ t❤✐s✱ ✐t ✇✐❧❧ ❤❛✈❡ t♦

• ❞❡t❡❝t ✇❤✐t❡ ❜♦①❡s ❛s ♦❜st❛❝❧❡s✱

• ❛♣♣r♦①✐♠❛t❡ t❤❡ ❞✐st❛♥❝❡ ❜❡t✇❡❡♥ ❝❛r ❛♥❞ ♦❜st❛❝❧❡✱

• ❛s ✇❡❧❧ ❛s t❤❡ ♦❜st❛❝❧❡ ❢r♦♥t✬s ✇✐❞t❤✳

❚♦ ❡♥❛❜❧❡ t❤❡ ❝❛r t♦ ❢✉❧✜❧❧ t❤❡s❡ t❛s❦s✱ t❤❡ ❝✉rr❡♥t s❡♥s♦r s❡t✉♣ ❤❛s t♦ ❜❡

❡①t❡♥❞❡❞ ✇✐t❤ ❛ s❡♥s♦r ❝❛♣❛❜❧❡ ♦❢ s❡♥s✐♥❣ ❞❡♣t❤ ✇❤✐❝❤ ❛❧s♦ ❤❛s t♦ ❜❡ ✐♥t❡❣r❛t❡❞

✐♥t♦ t❤❡ ❝✉rr❡♥t ❢r❛♠❡✇♦r❦✳ ❚❤❡♥ ❛ s♦❧✉t✐♦♥ ❢♦r ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ t❤❛t ❢✉❧✜❧❧s

t❤❡ t❤r❡❡ t❛s❦s ♠❡♥t✐♦♥❡❞ ❛❜♦✈❡ ❤❛s t♦ ❜❡ ❞❡✈❡❧♦♣❡❞ ❛♥❞ ✐♠♣❧❡♠❡♥t❡❞✳

❚❤❡ t❤✐r❞ ♣♦✐♥t ♦♥❧② ♠❡♥t✐♦♥s r❡❝♦♥str✉❝t✐♦♥ ♦❢ ♦❜st❛❝❧❡ ✇✐❞t❤✳ ❋♦r ✜♥❞✐♥❣

❛ tr❛❥❡❝t♦r② ❛r♦✉♥❞ ♦❜st❛❝❧❡s✱ ❦♥♦✇❧❡❞❣❡ ♦❢ ❛❧❧ ♦❢ t❤❡✐r ❞✐♠❡♥s✐♦♥s ✇♦✉❧❞ ❜❡

✐❞❡❛❧✳ ❇✉t ❛s t❤❡ ❈❛r♦❧♦✲❈✉♣ r✉❧❡s ❧✐♠✐t t❤❡ ❤❡✐❣❤t ♦❢ ♣❛rt✐❝✐♣❛t✐♥❣ ❝❛rs t♦ ✸✵

❝♠✱ t❤❡ t♦♣ s✉r❢❛❝❡s ♦❢ ♦❜st❛❝❧❡s ✇✐❧❧ ❜❡ ♦❝❝❧✉❞❡❞ ✐♥ ♠♦st ❝❛s❡s✳ ▼♦r❡♦✈❡r✱

t❤❡ ♠❛❥♦r✐t② ♦❢ ♦❜st❛❝❧❡s ✐s ♣❧❛❝❡❞ ✇✐t❤ ♦♥❡ s✐❞❡ ♣❛r❛❧❧❡❧ t♦ t❤❡ ❧❛♥❡ ♠❛r❦✐♥❣s✳

■♥ t❤✐s ❝❛s❡✱ ♦♥❧② t❤❡ ♦❜st❛❝❧❡ ❢r♦♥t ❢❛❝✐♥❣ t❤❡ ❝❛r ✇✐❧❧ ❜❡ ❞❡t❡❝t❛❜❧❡ ❜② ❛♥②

❦✐♥❞ ♦❢ s❡♥s♦r✳ ❚❤❡r❡❢♦r❡✱ t❤❡ ✇❤♦❧❡ t❛s❦ ♦❢ ❞❡t❡❝t✐♥❣ ♦❜st❛❝❧❡s ✐s r❡❞✉❝❡❞ t♦

❞❡t❡❝t✐♥❣ ♦❜st❛❝❧❡ ❢r♦♥ts ❛♥❞ r❡❝♦♥str✉❝t✐♦♥ ♦❢ t❤❡✐r ❞✐♠❡♥s✐♦♥s ✐s ❧✐♠✐t❡❞ t♦

♠❡❛s✉r✐♥❣ t❤❡✐r ✇✐❞t❤✳

❆s t❤❡ s♦❢t✇❛r❡ ✇✐❧❧ r✉♥ ✇✐t❤ ❧✐♠✐t❡❞ ❝♦♠♣✉t❛t✐♦♥❛❧ r❡s♦✉r❝❡s✱ ❛ s♣❡❝✐❛❧ ❢♦❝✉s

♦♥ ❢❛st r✉♥t✐♠❡ ❤❛s t♦ ❜❡ s❡t ❞✉r✐♥❣ ❞❡✈❡❧♦♣♠❡♥t ♦❢ t❤❡ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥

❛♣♣r♦❛❝❤✳

✷ ❇❛❝❦❣r♦✉♥❞

❚❤✐s s❡❝t✐♦♥ ✇✐❧❧ ♣r♦✈✐❞❡ t❤❡ t❤❡♦r❡t✐❝❛❧ ❜❛❝❦❣r♦✉♥❞ ♥❡❡❞❡❞ t❤r♦✉❣❤♦✉t t❤❡

r❡♠❛✐♥✐♥❣ ✇♦r❦✳ ■t st❛rts ❜② s❤♦rt❧② ❞❡s❝r✐❜✐♥❣ ❛ s✐♠♣❧❡ ❝❛♠❡r❛ ♠♦❞❡❧ ❛♥❞

❜❛s✐❝ ♣r♦❥❡❝t✐✈❡ ❣❡♦♠❡tr②✳ ❚❤✐s ✉♥❞❡rst❛♥❞✐♥❣ ♦❢ ♠♦♥♦ ♦❝✉❧❛r ✈✐s✐♦♥ ✇✐❧❧ t❤❡♥

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✷ ❇❛❝❦❣r♦✉♥❞ ❏❛♥♥✐s ■❤r✐❣

P

O

optical axis

f

❋✐❣✉r❡ ✷✿ P✐♥❤♦❧❡ ♠♦❞❡❧ ♦❢ ❛ ❝❛♠❡r❛✳

❜❡ ❡①t❡♥❞❡❞ t♦ st❡r❡♦ ✈✐s✐♦♥✳ ❍❡r❡ t❤❡ ❢♦❝✉s ✐s s❡t t♦ t❤❡ ❡①tr❛❝t✐♦♥ ♦❢ ❞❡♣t❤

✐♥❢♦r♠❛t✐♦♥ ❢r♦♠ ✐♠❛❣❡s✳ ❚❤❡ ❧❛st t✇♦ s✉❜s❡❝t✐♦♥s ❡①♣❧❛✐♥ ❞❛t❛ str✉❝t✉r❡s

t❤❛t ✇✐❧❧ ❢♦r♠ t❤❡ ❢♦✉♥❞❛t✐♦♥ ♦❢ t❤❡ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ♠❡t❤♦❞ ♣r♦♣♦s❡❞ ✐♥

s❡❝t✐♦♥ ✹✳

✷✳✶ ❈❛♠❡r❛ ♠♦❞❡❧ ❛♥❞ ❜❛s✐❝ ♣r♦❥❡❝t✐✈❡ ❣❡♦♠❡tr②

❚❤❡ ♣✐♥❤♦❧❡ ❝❛♠❡r❛ ♠♦❞❡❧ s❤♦✇♥ ✐♥ ✜❣✉r❡ ✷ ✐s ❛ s✐♠♣❧❡ ✇❛② t♦ r❡♣r❡s❡♥t ❛♥

✐❞❡❛❧ ❝❛♠❡r❛ ✭s❡❡ ❬✾✱ ♣✳ ✸✼✶✛❪✮✳ ■t ✐s ✉s❡❞ t♦ ❡①♣❧❛✐♥ t❤❡ ❜❛s✐❝ ❝♦♥❝❡♣t ♦❢

❝❛♠❡r❛s ❛♥❞ ❛♥❞ t❤❡✐r ✐♠♣♦rt❛♥t ♣❛r❛♠❡t❡rs t❤❛t ❛r❡ ✉s❡❞ t❤r♦✉❣❤♦✉t t❤✐s

✇♦r❦✳

❆♥ ■♠❛❣❡ ❛r✐s❡s ❢r♦♠ ❧✐❣❤t✱ r❡✢❡❝t❡❞ ❢r♦♠ ♦❜❥❡❝ts ❛♥❞ ❢❛❧❧✐♥❣ ✐♥t♦ t❤❡ ❝❛♠❡r❛

t❤r♦✉❣❤ t❤❡ ❝❛♠❡r❛ ♦♣❡♥✐♥❣✳ ■t ✐s ♠♦❞❡❧❡❞ ❛s r❛②s t❤❛t ❛❧❧ ♣❛ss t❤r♦✉❣❤

❛ ❝♦♠♠♦♥ ♣♦✐♥t✱ t❤❡ ❝❡♥t❡r ♦❢ ♣r♦❥❡❝t✐♦♥ O✳ ❚❤❡ ✐♠❛❣❡ ♣❧❛♥❡ ✐s ♣❧❛❝❡❞ ✐♥

❢r♦♥t ♦❢ t❤❡ ❝❡♥t❡r ♦❢ ♣r♦❥❡❝t✐♦♥✳ ❚❤❡ ♣r♦❥❡❝t✐♦♥ p = [x, y]T ♦❢ t❤❡ ♣♦✐♥t

P = [X, Y, Z]T ✐♥ t❤r❡❡✲❞✐♠❡♥s✐♦♥❛❧ s♣❛❝❡ ✐s ❝r❡❛t❡❞ ❜② ✐♥t❡rs❡❝t✐♥❣ t❤❡ r❛②

❢r♦♠ P t♦ t❤❡ ❝❡♥t❡r ♦❢ ♣r♦❥❡❝t✐♦♥ ✇✐t❤ t❤❡ ✐♠❛❣❡ ♣❧❛♥❡✳ ❆❧❧ ♣r♦❥❡❝t✐♦♥ ♦♥

t❤❡ ✐♠❛❣❡ ♣❧❛♥❡ t♦❣❡t❤❡r t❤❡♥ r❡s✉❧t ✐♥ ❛♥ ✐♠❛❣❡ ♦❢ t❤❡ s❝❡♥❡ ✐♥ ❢r♦♥t ♦❢ t❤❡

❝❛♠❡r❛✳

❚❤❡ r❛② t❤❛t ♦r✐❣✐♥❛t❡s ❢r♦♠ t❤❡ ❝❡♥t❡r ♦❢ ♣r♦❥❡❝t✐♦♥ ❛♥❞ ♦rt❤♦❣♦♥❛❧❧② ♣❛ss❡s

t❤r♦✉❣❤ t❤❡ ✐♠❛❣❡ ♣❧❛♥❡ ✐s ❝❛❧❧❡❞ t❤❡ ♦♣t✐❝❛❧ ❛①✐s ♦❢ t❤❡ ❝❛♠❡r❛✳ ■t ❞❡s❝r✐❜❡s t❤❡

❝❛♠❡r❛s ♠❛✐♥ ✈✐❡✇✐♥❣ ❞✐r❡❝t✐♦♥✳ ❚❤❡ ♣♦✐♥t ✐♥ ✇❤✐❝❤ t❤❡ ♦♣t✐❝❛❧ ❛①✐s ✐♥t❡rs❡❝ts

t❤❡ ✐♠❛❣❡ ♣❧❛♥❡ ✐s ❝❛❧❧❡❞ ♣r✐♥❝✐♣❛❧ ♣♦✐♥t c✳ ❋✐❣✉r❡ ✷ ❛❧s♦ s❤♦✇s t❤❛t ♠♦❞✐❢②✐♥❣

t❤❡ ❞✐st❛♥❝❡ ❜❡t✇❡❡♥ t❤❡ ❝❡♥t❡r ♦❢ ♣r♦❥❡❝t✐♦♥ ❛♥❞ t❤❡ ✐♠❛❣❡ ♣❧❛♥❡ ❝❤❛♥❣❡s t❤❡

❧♦❝❛t✐♦♥s ♦❢ ♣r♦❥❡❝t❡❞ ♣♦✐♥ts✳ ❚❤✐s ❞✐st❛♥❝❡ ✐s ❝❛❧❧❡❞ t❤❡ ❢♦❝❛❧ ❧❡♥❣t❤ f ✳

Page 12: Obstacle detection for an autonomous model car …...a stereo vision based real-time obstacle detection system for an autonomous model car on the scale of 1:10 built for the annual

✷ ❇❛❝❦❣r♦✉♥❞ ❏❛♥♥✐s ■❤r✐❣

❲✐t❤ t❤❡ ❤❡❧♣ ♦❢ s✐♠✐❧❛r tr✐❛♥❣❧❡s ✐t ✐s ♣♦ss✐❜❧❡ t♦ ❢♦r♠✉❧❛t❡ ❢♦❧❧♦✇✐♥❣ ❡q✉❛t✐♦♥s✿

x =fX

Z✱ y =

fY

Z✭✶✮

❚❤❡② ❞❡t❡r♠✐♥❡ t❤❡ ♣r♦❥❡❝t✐♦♥ p ❢♦r ❛ ❣✐✈❡♥ ♣♦✐♥t P ✐❢ t❤❡ ❢♦❝❛❧ ❧❡♥❣t❤ f ♦❢ t❤❡

❝❛♠❡r❛ ✐s ❦♥♦✇♥✳ p ✐s ❞❡s❝r✐❜❡❞ ✐♥ t❤❡ ✐♠❛❣❡ ❝♦♦r❞✐♥❛t❡ ❢r❛♠❡✳ ❇✉t ❞✉❡ t♦

✐♥❛❝❝✉r❛❝✐❡s ✐♥ r❡❛❧ ❝❛♠❡r❛s✱ t❤❡ ✐s ♣r✐♥❝✐♣❛❧ ♣♦✐♥t ❛❧♠♦st ♥❡✈❡r ✐❞❡♥t✐❝❛❧ ✇✐t❤

t❤❡ ✐♠❛❣❡ ❝❡♥t❡r✳ ❚❤❡r❡❢♦r❡ t❤❡ ♦✛s❡ts cx ❛♥❞ cy ❛r❡ ✐♥tr♦❞✉❝❡❞ t♦ ❡q✉❛t✐♦♥s

✶✳

x =fX

Z+ cx✱ y =

fY

Z+ cy ✭✷✮

❚❤❡s❡ ♥❡✇ ❡q✉❛t✐♦♥s st✐❧❧ ✐❣♥♦r❡ t❤❡ ❢❛❝t t❤❛t ♠♦st ❧❡♥s❡s ✇✐❧❧ ✐♥✢✉❡♥❝❡ t❤❡

♣r♦❥❡❝t✐♦♥ ❛♥❞ ❞✐st♦rt ✐♠❛❣❡s✳ ❇✉t ❛s ❞✐st♦rt✐♦♥ ❝❛♥ ❜❡ ❝♦✉♥t❡r❛❝t❡❞ ❛s s❤♦✇♥

✐♥ ❬✾✱ ♣✳ ✸✼✺✛❪✱ t❤❡ r❡st ♦❢ t❤✐s ✇♦r❦ ✇✐❧❧ ❛ss✉♠❡ ✉♥❞✐st♦rt❡❞ ✐♠❛❣❡s✳

f ✱ cx ❛♥❞ cy t♦❣❡t❤❡r ❛r❡ ❝❛❧❧❡❞ t❤❡ ❝❛♠❡r❛✬s ✐♥tr✐♥s✐❝ ♣❛r❛♠❡t❡rs✳ ■❢ t❤❡ ❡q✉❛✲

t✐♦♥s ✷ ❛r❡ r❡✇r✐tt❡♥ ❛s t❤❡ ❝❛♠❡r❛ ♠❛tr✐①✱ ✐t ❝❛♥ ❜❡ ✉s❡❞ t♦ ❡❛s✐❧② ❝❛❧❝✉❧❛t❡

t❤❡ ♣r♦❥❡❝t✐♦♥ ❢♦r ❛ ♣♦✐♥t P = [X, Y, Z]T ✿

x

y

w

=

X

Y

Z

f 0 cx

0 f cy

0 0 1

✭✸✮

❚❤❡ ♣r♦❥❡❝t❡❞ ♣♦✐♥t p ✐s r❡♣r❡s❡♥t❡❞ ✐♥ ❤♦♠♦❣❡♥❡♦✉s ❝♦♦r❞✐♥❛t❡s✳ ❚❤✐s r❡s✉❧ts

❢r♦♠ t❤❡ ❢❛❝t t❤❛t ❛❧❧ ♣♦✐♥ts ♦♥ t❤❡ s❛♠❡ r❛② ❢❛❧❧✐♥❣ ✐♥t♦ t❤❡ ❝❛♠❡r❛ ♣r♦❞✉❝❡

t❤❡ s❛♠❡ ♣r♦❥❡❝t✐♦♥ ♦♥ t❤❡ ✐♠❛❣❡ ♣❧❛♥❡✳ ❚❤❡ ❡①❛❝t ✐♠❛❣❡ ❝♦♦r❞✐♥❛t❡s ❢♦r ♣

❛r❡ p = [ xw, y

w]T ✳ ❙t❡r❡♦ ✈✐s✐♦♥ r❡s♦❧✈❡s t❤✐s ❛♠❜✐❣✉✐t② ❛♥❞ ❛❧❧♦✇s t♦ r❡♣r♦❥❡❝t

❢r♦♠ ❛ ❣✐✈❡♥ ♣♦✐♥t ♣ t♦ ❛ ♣♦✐♥t P ✐♥ t❤❡ t❤r❡❡✲❞✐♠❡♥s✐♦♥❛❧ ✇♦r❧❞✳ ■t t❤❡r❡❢♦r❡

✇✐❧❧ ❜❡ t❤❡ s✉❜❥❡❝t ♦❢ t❤❡ ❢♦❧❧♦✇✐♥❣ s❡❝t✐♦♥✳

✷✳✷ ❙t❡r❡♦ ✈✐s✐♦♥

P❡r❝❡✐✈✐♥❣ ❞❡♣t❤ t❤r♦✉❣❤ st❡r❡♦ ✈✐s✐♦♥ ✇✐t❤ t❤❡ t✇♦ ❡②❡s ♦❢ ❛ ♣❡rs♦♥ ❝❛♥ ❜❡

❡①♣❡r✐❡♥❝❡❞ ✐♥ ❡✈❡r②❞❛② ❧✐❢❡✳ ❈♦♠♣✉t❡r ✈✐s✐♦♥ tr✐❡s t♦ ❡♠✉❧❛t❡ t❤✐s ❝❛♣❛❜✐❧✐t②

❜② ✉s✐♥❣ t✇♦ ❝❛♠❡r❛s ✐♥ ♦♥❡ st❡r❡♦ ✈✐s✐♦♥ s②st❡♠✳ ❉❡♣t❤ ✐♥❢♦r♠❛t✐♦♥ ❛r❡ t❤❡♥

r❡❝♦♥str✉❝t❡❞ ❢r♦♠ ♣r♦❥❡❝t✐♦♥s ❢♦✉♥❞ ♦♥ ❜♦t❤ ✐♠❛❣❡s✳ ❚❤❡ ❢♦❧❧♦✇✐♥❣ s❡❝t✐♦♥

s❤♦rt❧② ❞❡s❝r✐❜❡s ❤♦✇ t❤✐s ✐s ❛❝❤✐❡✈❡❞ ❛♥❞ s♦♠❡ ♣r♦♣❡rt✐❡s ♦❢ t❤❡ r❡s✉❧t✐♥❣

❞❡♣t❤ ♠❡❛s✉r❡ ❝❛❧❧❡❞ ❞✐s♣❛r✐t②✳

Page 13: Obstacle detection for an autonomous model car …...a stereo vision based real-time obstacle detection system for an autonomous model car on the scale of 1:10 built for the annual

✷ ❇❛❝❦❣r♦✉♥❞ ❏❛♥♥✐s ■❤r✐❣

Ol Or

P

Ir

Il

epipolar Line

epipole

❋✐❣✉r❡ ✸✿ Pr♦❥❡❝t✐♦♥ ♦❢ ♣♦✐♥t P ♦♥ t✇♦ ❛r❜✐tr❛r✐❧② ♣♦s✐t✐♦♥❡❞ ✐♠❛❣❡ ♣❧❛♥❡s✳ ❊♣✐♣♦❧❛r

❣❡♦♠❡tr② ❞❡✜♥❡s t❤❡ ❡♣✐♣♦❧❡s el ❛♥❞ er✳ ❋♦r ❛ ❣✐✈❡♥ ♣r♦❥❡❝t✐♦♥ pl✱ t❤❡ ♣r♦❥❡❝t✐♦♥ ♦❢

P ♦♥t♦ t❤❡ ✐♠❛❣❡ Ir ❤❛s t♦ ❜❡ ❧♦❝❛t❡❞ ♦♥ t❤❡ ❡♣✐♣♦❧❛r ❧✐♥❡ ♦♥ Ir✳ ❚❤✐s ❧✐♥❡ ✐s

♦❜t❛✐♥❡❞ ❜② ✐♥t❡rs❡❝t✐♥❣ t❤❡ ♣❧❛♥❡ s♣❛♥♥❡❞ ❜② Ol✱ Or ❛♥❞ P ✇✐t❤ Ir✳

✷✳✷✳✶ ❊♣✐♣♦❧❛r ❣❡♦♠❡tr②

❲✐t❤ t❤❡ ❤❡❧♣ ♦❢ ❡♣✐♣♦❧❛r ❣❡♦♠❡tr②✱ t❤❡ ♣♦s✐t✐♦♥ ♦❢ ✷ ✐♠❛❣❡s ✐♥ t❤r❡❡✲❞✐♠❡♥s✐♦♥❛❧

s♣❛❝❡ ❝❛♥ ❜❡ r❡❧❛t❡❞ t♦ ❡❛❝❤ ♦t❤❡r✳ ■t ✐s ✉s❡❞ t♦ s✐♠♣❧✐❢② t❤❡ ❝♦rr❡s♣♦♥❞❡♥❝❡

♣r♦❜❧❡♠ ✐♥ st❡r❡♦ ✈✐s✐♦♥ ❜② ✉❧t✐♠❛t❡❧② r❡❞✉❝✐♥❣ t❤❡ ✐♠❛❣❡ ❛r❡❛ t❤❛t ❤❛s t♦ ❜❡

s❡❛r❝❤❡❞ ❢♦r ❝♦rr❡s♣♦♥❞✐♥❣ ♣♦✐♥ts✳

▲❡t P ❜❡ ❛ ♣♦✐♥t✱ Il ❛♥❞ Ir t✇♦ ✐♠❛❣❡ ♣❧❛♥❡s✱ Ol ❛♥❞ Or t❤❡✐r ❝❡♥t❡r ♦❢

♣r♦❥❡❝t✐♦♥ ❛♥❞ Pl ❛♥❞ Pr t❤❡ t✇♦ ♣r♦❥❡❝t✐♦♥s ♦❢ P ♦♥ t❤❡s❡ ✐♠❛❣❡ P❧❛♥❡s✳ ❚❤❡

✜rst st❡♣ ✐s ♥♦✇ t♦ ✐♥tr♦❞✉❝❡ t✇♦ ❢✉rt❤❡r ♣♦✐♥ts ❝❛❧❧❡❞ t❤❡ ❡♣✐♣♦❧❡s✳ el ❛♥❞

er ❛r❡ ❞❡✜♥❡❞ ❛s t❤❡ ♣r♦❥❡❝t✐♦♥ ♦❢ Or ♦♥ Il ❛♥❞ Ol ♦♥ Ir✱ r❡s♣❡❝t✐✈❡❧②✳ ■♥ ❛

s❡❝♦♥❞ st❡♣ ✇❡ ❞❡✜♥❡ t❤❡ ❡♣✐♣♦❧❛r ♣❧❛♥❡ ❛s s♣❛♥♥❡❞ ❜② t❤❡ t✇♦ ❡♣✐♣♦❧❡s ❛♥❞ P ✳

❆s ❝❛♥ ❜❡ s❡❡♥ ✐♥ ✜❣✉r❡ ✸✱ t❤❡ ❝❡♥t❡rs ♦❢ ♣r♦❥❡❝t✐♦♥ ❜♦t❤ ❧❛② ♦♥ t❤❡ ❡♣✐♣♦❧❛r

♣❧❛♥❡ ❛♥❞ t❤❡r❡❢♦r❡ P r❡s✉❧ts ✐♥ ❛ ♣r♦❥❡❝t✐♦♥ ♦♥ ❜♦t❤ ✐♠❛❣❡s✳ ❚❤❡ s❛♠❡ ♣❧❛♥❡

❝❛♥ ❜❡ s♣❛♥♥❡❞ ❜② t❤❡ t❤r❡❡ ♣♦✐♥ts Pl✱ el ❛♥❞ Ol✳ ❚❤❡♥ t❤❡ Pr ❤❛s t♦ ❧❛② ♦♥

t❤❡ ✐♥t❡rs❡❝t✐♦♥ ♦❢ t❤❡ ❡♣✐♣♦❧❛r ♣❧❛♥❡ ❛♥❞ Ir✱ ❢♦r♠✐♥❣ ✇❤❛t ✐s ❝❛❧❧❡❞ ❛ ❡♣✐♣♦❧❛r

❧✐♥❡✳ ❖♥❧② t❤❡ ❡♣✐♣♦❧❛r ❧✐♥❡ ❤❛s t♦ ❜❡ s❡❛r❝❤❡❞ t♦ ✜♥❞ t❤❡ ♣r♦❥❡❝t✐♦♥ Pr ✐❢ t❤❡

♣❤②s✐❝❛❧ ❧♦❝❛t✐♦♥ ♦❢ Ir r❡❧❛t✐✈❡ t♦ Il ✐s ❦♥♦✇♥✳

❚♦ ❞❡s❝r✐❜❡ t❤✐s r❡❧❛t✐♦♥s❤✐♣✱ t❤❡ ❡ss❡♥t✐❛❧ ♠❛tr✐① ❛♥❞ t❤❡ ❢✉♥❞❛♠❡♥t❛❧ ♠❛tr✐①

❝❛♥ ❜❡ ❝♦♠♣✉t❡❞✳ ❚❤❡ ❡ss❡♥t✐❛❧ ♠❛tr✐① ❝♦♥t❛✐♥s t❤❡ r♦t❛t✐♦♥ ❛♥❞ tr❛♥s❧❛t✐♦♥ t♦

❞❡s❝r✐❜❡ t❤❡ ♣❤②s✐❝❛❧ ❧♦❝❛t✐♦♥ ♦❢ t❤❡ s❡❝♦♥❞ ❝❛♠❡r❛ ✐♠❛❣❡ r❡❧❛t✐✈❡ t♦ t❤❡ ✜rst✳

❲✐t❤ ✐ts ❤❡❧♣ ❛♥❞ t❤❡ ✐♥tr✐♥s✐❝ ♣❛r❛♠❡t❡rs ♦❢ ❜♦t❤ ❝❛♠❡r❛s✱ t❤❡ ❢✉♥❞❛♠❡♥t❛❧

♠❛tr✐① ❝❛♥ ❜❡ ❝♦♠♣✉t❡❞ ❛♥❞ r❡❧❛t❡s t❤❡ s✐♥❣❧❡ ♣✐①❡❧s ♦❢ ❜♦t❤ ✐♠❛❣❡s t♦ ❡❛❝❤

♦t❤❡r✳ ❚❤❡ ❡①❛❝t ♠❛t❤ t♦ ❝♦♠♣✉t❡ ❜♦t❤ ♠❛tr✐❝❡s ❣♦❡s ❢❛r ❜❡②♦♥❞ t❤❡ s❝♦♣❡

Page 14: Obstacle detection for an autonomous model car …...a stereo vision based real-time obstacle detection system for an autonomous model car on the scale of 1:10 built for the annual

✷ ❇❛❝❦❣r♦✉♥❞ ❏❛♥♥✐s ■❤r✐❣

ol

or

y

YB

P

Z

Il

Ir

❋✐❣✉r❡ ✹✿ Pr♦❥❡❝t✐♦♥ ♦❢ ♣♦✐♥t P ♦♥t♦ t✇♦ ✉♥❞✐st♦rt❡❞✱ r❡❝t✐✜❡❞ ❛♥❞ r♦✇✲❛❧✐❣♥❡❞

✐♠❛❣❡s ✇✐t❤ ♣❛r❛❧❧❡❧ ✐♠❛❣❡ ♣❧❛♥❡s✳ ❚❤✐s s❡t✉♣ ❛❧❧♦✇s t♦ ❝❛❧❝✉❧❛t❡ t❤❡ ❞✐s♣❧❛❝❡♠❡♥t d

❜❡t✇❡❡♥ pl ❛♥❞ pr✳ ❚❤❡♥✱ t❤❡ ❞✐st❛♥❝❡ Z ❜❡t✇❡❡♥ P ❛♥❞ t❤❡ ✐♠❛❣❡ ♣❧❛♥❡s ❝❛♥ ❜❡

♦❜t❛✐♥❡❞ ✈✐❛ s✐♠✐❧❛r tr✐❛♥❣❧❡s✳

♦❢ t❤✐s ✇♦r❦✳ ❙❡❡ ❬✶✵✱ ♣✳ ✸✶✛❪ ❛♥❞ ❬✾✱ ♣✳ ✹✷✶✛❪ ❢♦r ❢✉rt❤❡r ❞❡t❛✐❧✳

✷✳✷✳✷ ❈❛❧✐❜r❛t❡❞ st❡r❡♦ ✈✐s✐♦♥

❆ s②st❡♠ ✉s❡❞ ❢♦r st❡r❡♦ ✈✐s✐♦♥ ❝♦♥s✐sts ♦❢ t✇♦ s✐♥❣❧❡ ❝❛♠❡r❛s t❤❛t ❤❛✈❡ t❤❡

s❛♠❡ ❢♦❝❛❧ ❧❡♥❣t❤✳ ❚❤❡ t❤❡♦r② ♦❢ ❡♣✐♣♦❧❛r ❣❡♦♠❡tr② ❝❛♥ ❜❡ ✉s❡❞ t♦ ❝❛❧✐❜r❛t❡

t❤❡♠ ❛♥❞ r❡❝t✐❢② t❤❡✐r ✐♠❛❣❡s✶✳ ❚❤❡ r❡s✉❧t ✐s ❛ ♣❛✐r ♦❢ tr❛♥s❢♦r♠❡❞ ✐♠❛❣❡s t❤❛t

r❡s✐❞❡ ♦♥ t❤❡ s❛♠❡ ♣❧❛♥❡ ❛♥❞ ❛r❡ ❡①❛❝t❧② r♦✇ ❛❧✐❣♥❡❞ ✭❬✶✵✱ ♣✳ ✺✺❪ ❛♥❞ ❬✾✱ ♣✳

✹✷✼✛❪✮✳ ■♥ t❤❡ ♣r♦❝❡ss✱ t❤❡ ♣♦s✐t✐♦♥ ♦❢ ❜♦t❤ ❡♣✐♣♦❧❡s ❣❡ts s❤✐❢t❡❞ t♦ ✐♥✜♥✐t② s♦

t❤❛t t❤❡ ❡♣✐♣♦❧❛r ❧✐♥❡s ❜❡❝♦♠❡ ♣❛r❛❧❧❡❧ ❛♥❞ ❝♦❧❧✐♥❡❛r t♦ t❤❡ r♦✇s ♦❢ t❤❡ ✐♠❛❣❡s✳

▲❡t P ❜❡ ❛ ♣♦✐♥t ✐♥ t❤r❡❡✲❞✐♠❡♥s✐♦♥❛❧ s♣❛❝❡ ❛♥❞ pl ✐ts ♣r♦❥❡❝t✐♦♥ ♦♥ t❤❡ ❧❡❢t

✐♠❛❣❡ Il✳ ❚♦ ✜♥❞ t❤❡ ❝♦rr❡s♣♦♥❞✐♥❣ ♣♦✐♥t pr ♦♥ t❤❡ r✐❣❤t ✐♠❛❣❡ Ir✱ ✐t ✐s ♥♦✇

♦♥❧② ♥❡❝❡ss❛r② t♦ s❡❛r❝❤ t❤❡ s❛♠❡ r♦✇ ❢♦r ❛ ♠❛t❝❤✳✷ ◆♦t❡ t❤❛t pl = [xl, yr]T

❛♥❞ pr = [xr, yr]T ❤❡r❡ ❞❡s❝r✐❜❡ ♣✐①❡❧s ♦♥ t❤❡ ✐♠❛❣❡✳ ❆s ❛♥ ❛❞❞✐t✐♦♥❛❧ ❡✛❡❝t✱

t❤❡ ♦♣t✐❝❛❧ ❛①✐s ❢♦r t❤❡ r❡❝t✐✜❡❞ ✐♠❛❣❡s ❛r❡ ♣❛r❛❧❧❡❧✱ s♦ t❤❛t ❢♦❧❧♦✇✐♥❣ ❡q✉❛t✐♦♥

❝❛♥ ❜❡ ♦❜t❛✐♥❡❞ ✇✐t❤ t❤❡ ❤❡❧♣ ♦❢ s✐♠✐❧❛r tr✐❛♥❣❧❡s ✭s❡❡ ✜❣✉r❡ ✹✱ ❬✾✱ ♣✳ ✹✶✺✛❪

❛♥❞ ❬✶✵✱ ♣✳ ✻✻❪✮✿B

Z=

B − (xl − xr)

Z − f✭✹✮

❍❡r❡ B ❞❡♥♦t❡s t❤❡ ❞✐st❛♥❝❡ ❜❡t✇❡❡♥ t❤❡ ❝❡♥t❡rs ♦❢ ♣r♦❥❡❝t✐♦♥ ❢♦r t❤❡ r❡❝t✐✜❡❞

✶❚❤❛t ✐s ✇❤② t❤✐s s❡❝t✐♦♥ ✐s ❝❛❧❧❡❞ ❈❛❧✐❜r❛t❡❞ st❡r❡♦ ✈✐s✐♦♥✳ ▼❡t❤♦❞s ❢♦r ✉♥❝❛❧✐❜r❛t❡❞st❡r❡♦ ✈✐s✐♦♥ ❛❧s♦ ❡①✐st✱ ❛s s❤♦✇♥ ✐♥ ❬✾✱ ♣✳ ✹✸✶❪✳

✷❚❤✐s ✐s ❝❛❧❧❡❞ t❤❡ ❝♦rr❡s♣♦♥❞❡♥❝❡ ♣r♦❜❧❡♠ ❛♥❞ ✇✐❧❧ ♥♦t ❜❡ ❞✐s❝✉ss❡❞ ✐♥ ❞❡♣t❤✳ ❋♦r ❢✉rt❤❡r❞❡t❛✐❧ s❡❡ ❬✾✱ ♣✳ ✹✸✽❪

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✷ ❇❛❝❦❣r♦✉♥❞ ❏❛♥♥✐s ■❤r✐❣

0

20

40

60

80

100

0 1 2 3 4 5 6

disparity

in pixels

distance in m

❋✐❣✉r❡ ✺✿ ❘❡❧❛t✐♦♥ ❜❡t✇❡❡♥ ❞✐st❛♥❝❡ ❛♥❞ ❞✐s♣❛r✐t②✳ ❚❤✐s ❣r❛♣❤ ✇❛s ♣❧♦tt❡❞ ❢♦r ❢ ❂

✻✷✵ ❛♥❞ ❇ ❂ ✵✳✵✼✸✳

✐♠❛❣❡s ✐♥ ♠❡t❡r ❛♥❞ ✐s ❝❛❧❧❡❞ t❤❡ ❜❛s❡ ❧✐♥❡✳ f ✐s t❤❡ ❝♦♠♠♦♥ ❢♦❝❛❧ ❧❡♥❣t❤ ♦❢

t❤❡ r❡❝t✐✜❡❞ ✐♠❛❣❡s ❛♥❞ Z t❤❡ ❞✐st❛♥❝❡ ❜❡t✇❡❡♥ t❤❡ ❝❛♠❡r❛ ❛♥❞ P ✐♥ ♠❡t❡r✳

❚❤❡ ❞✐s♣❧❛❝❡♠❡♥t d = xl − xr ❜❡t✇❡❡♥ t❤❡ ❝♦rr❡❧❛t❡❞ ♣♦✐♥ts ♦♥ t❤❡ ❧❡❢t ❛♥❞

r✐❣❤t ✐♠❛❣❡ ✐s ❝❛❧❧❡❞ ❞✐s♣❛r✐t②✸ ❛♥❞ ♠❡❛s✉r❡❞ ✐♥ ♣✐①❡❧s✳ ■❢ ❡q✉❛t✐♦♥ ✭✹✮ ✐s

tr❛♥s❢♦r♠❡❞ t♦

Z =fB

d✭✺✮

t❤❡ r❡❧❛t✐♦♥ ❜❡t✇❡❡♥ t❤❡ ❞✐s♣❛r✐t② ❢♦r pl ❛♥❞ pr ❛♥❞ t❤❡ ❞✐st❛♥❝❡ t♦ P ❜❡❝♦♠❡s

❝❧❡❛r❡r✳ f ❛♥❞ B ❛r❡ ✜①❡❞ ✈❛❧✉❡s✳ ❚❤✐s ♠❛❦❡s ✐t ♣♦ss✐❜❧❡ t♦ ❞❡t❡r♠✐♥❡ t❤❡

❞✐st❛♥❝❡ Z ✐♥ ♠❡t❡r ❜❡t✇❡❡♥ ❝❛♠❡r❛ ❛♥❞ ♣♦✐♥t P ✱ t❤❡ ❝❡♥tr❛❧ ❣♦❛❧ ♦❢ st❡r❡♦

✈✐s✐♦♥✳

■❢ t❤❡ ❞✐s♣❛r✐t✐❡s ❢♦r ❡❛❝❤ ♣✐①❡❧ ♦❢ ♦♥❡ ✐♠❛❣❡ ❛r❡ ❝❛❧❝✉❧❛t❡❞✱ t❤❡s❡ ✈❛❧✉❡s ❢♦r♠

❛♥ ✐♠❛❣❡ ❝♦♠♠♦♥❧② ❝❛❧❧❡❞ ❞✐s♣❛r✐t② ♠❛♣✳ ❆s t❤❡ ❝♦rr❡❧❛t✐♥❣ pr ♠❛② ♥♦t ❜❡

❢♦✉♥❞ ❢♦r ❡❛❝❤ pl✱ ✐t ✐s ♣♦ss✐❜❧❡ t❤❛t ♣❛rts ♦❢ t❤❡ ♠❛♣ ❝♦♥t❛✐♥ ✐♥✈❛❧✐❞ ✈❛❧✉❡s✳

❚❤✐s ✐s ❢✉rt❤❡r ❝❛❧❧❡❞ ❛ s♣❛rs❡ ❞✐s♣❛r✐t② ♠❛♣✳

✷✳✷✳✸ Pr♦♣❡rt✐❡s ♦❢ ❞✐s♣❛r✐t②

❋✐❣✉r❡ ✺ s❤♦✇s t❤❡ ✐♥✈❡rs❡ r❡❧❛t✐♦♥ ❜❡t✇❡❡♥ ❞✐s♣❛r✐t② ❛♥❞ ❛❝t✉❛❧ ❞✐st❛♥❝❡✳ ■t

❝❛♥ ❜❡ ❞❡❞✉❝❡❞ ❢r♦♠ ❡q✉❛t✐♦♥ ✭✺✮ ❛♥❞ ✐s ❞❡♣❡♥❞❡♥t ♦♥ t❤❡ ❝♦♠♠♦♥ ❢♦❝❛❧ ❧❡♥❣t❤

♦❢ t❤❡ ❝❛♠❡r❛s ❛♥❞ t❤❡ ❜❛s❡ ❞✐st❛♥❝❡ ❜❡t✇❡❡♥ t❤❡♠✳ ❚❤❡ ♣❧♦t ❛❧s♦ s❤♦✇s t❤❛t

t❤❡ ❞✐s♣❛r✐t② r❡s♦❧✉t✐♦♥ ❢♦r ❝❧♦s❡ ♣♦✐♥ts ✐s ❤✐❣❤❡r t❤❛♥ ❢♦r ♣♦✐♥ts ❢✉rt❤❡r ❛✇❛②

❢r♦♠ t❤❡ st❡r❡♦ ❝❛♠❡r❛✳ ❋✉rt❤❡r♠♦r❡✱ t❤❡ ♠❛①✐♠✉♠ ❞✐s♣❛r✐t② ✐s ❞❡✜♥❡❞ ❜②

t❤❡ ✈❡rt✐❝❛❧ r❡s♦❧✉t✐♦♥ ♦❢ ✐♠❛❣❡s ❛s ♣♦✐♥ts ♠❛② ❜❡ t♦ ❝❧♦s❡ t♦ t❤❡ st❡r❡♦ r❛❝❦

t♦ s❤♦✇ ✉♣ ♦♥ ❜♦t❤ ✐♠❛❣❡s✳ P♦✐♥ts ❛t ❢❛r ❞✐st❛♥❝❡s ✇✐❧❧ ❜❡ ♣r♦❥❡❝t❡❞ ♦♥ t❤❡

✸❍❡r❡✱ ♦♥❧② ❤♦r✐③♦♥t❛❧ ❞✐s♣❛r✐t② ✐s ❞❡s❝r✐❜❡❞✳ ❙t❡r❡♦ ❝❛♠❡r❛ r❛❝❦s ✇✐t❤ ✈❡rt✐❝❛❧❧② ❛r✲r❛♥❣❡❞ ❝❛♠❡r❛s ♣r♦❞✉❝❡ ❛ ✈❡rt✐❝❛❧ ❞✐s♣❛r✐t② t❤❛t ✐s t❤❡ ✈❡rt✐❝❛❧ ❞✐s♣❧❛❝❡♠❡♥t ♦❢ ❢❡❛t✉r❡s✳❙❡❡ ❢♦♦t♥♦t❡ ♦♥ ❬✾✱ ♣✳ ✹✶✺❪✳

✶✵

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✷ ❇❛❝❦❣r♦✉♥❞ ❏❛♥♥✐s ■❤r✐❣

s❛♠❡ ♣✐①❡❧ ❝♦♦r❞✐♥❛t❡s ♦♥ ❜♦t❤ ✐♠❛❣❡s ❛s t❤❡ ♥✉♠❜❡r ♦❢ ♣✐①❡❧s ✐♥ ♦♥❡ r♦✇ ✐s

✜♥✐t❡✳ ❚❤✐s r❡s✉❧ts ✐♥ ❛ ❞✐s♣❛r✐t② ♦❢ ✵ ❛♥❞ t❤❡r❡❢♦r❡ ❧✐♠✐ts t❤❡ ❛r❡❛ ❢♦r r❡s♦❧✈✐♥❣

❞❡♣t❤ ❛t t❤❡ ❞✐st❛♥❝❡✳ ❋♦❝❛❧ ❧❡♥❣t❤✱ ❜❛s❡ ❞✐st❛♥❝❡ ❛♥❞ ✈❡rt✐❝❛❧ r❡s♦❧✉t✐♦♥s ❛r❡

✜①❡❞ ♣❛r❛♠❡t❡rs ❢♦r ❛ st❡r❡♦ ❝❛♠❡r❛✳ ❚❤✉s ❡✈❡r② st❡r❡♦ ❝❛♠❡r❛ ❤❛s ❛ ❞❡✜♥❡❞

t❤r❡❡✲❞✐♠❡♥s✐♦♥❛❧ r❡❣✐♦♥ ✐♥ ✇❤✐❝❤ ✐t ❝❛♥ r❡s♦❧✈❡ ❞✐st❛♥❝❡s ✇✐t❤ t❤❡ ❤❡❧♣ ♦❢

❢♦✉♥❞ ❞✐s♣❛r✐t✐❡s✳

❋✐❣✉r❡ ✹ s❤♦✇s t❤❛t t❤❡ ❞✐s♣❛r✐t② ❛❝t✉❛❧❧② ❞❡s❝r✐❜❡s t❤❡ ❞✐st❛♥❝❡ ♦❢ ❛ ♣♦✐♥t t♦

t❤❡ ❜❛s❡ ❧✐♥❡ ♦❢ t❤❡ ❝❛♠❡r❛✳ ❲✐t❤ t❤✐s ❛ ❣✐✈❡♥ ❞✐s♣❛r✐t② ❞❡✜♥❡s ❛ ♣❧❛♥❡ ♣❛r❛❧❧❡❧

t♦ t❤❡ ✐♠❛❣❡ ♣❧❛♥❡✳ ■t ❡①♣❧❛✐♥s ✇❤② ❛❧❧ ♣♦✐♥ts ♦♥ ❛ r♦✇ ♦❢ t❤❡ ✐♠❛❣❡ ❛❧❧ ❤❛✈❡ t❤❡

s❛♠❡ ❞✐s♣❛r✐t② ✐❢ t❤❡ ✐♠❛❣❡ ✐s s❤♦✇✐♥❣ ❛ ♣❧❛♥❛r s✉r❢❛❝❡ ❛♥❞ t❤❡ ❝❛♠❡r❛s ❜❛s❡

❧✐♥❡ ✐s ♣❛r❛❧❧❡❧ t♦ ✐t✳ ❆❞❞✐t✐♦♥❛❧❧②✱ t❤❡ r❡❧❛t✐♦♥ ❜❡t✇❡❡♥ t❤❡ ❞✐s♣❛r✐t② ✈❛❧✉❡s

❛♥❞ t❤❡ ②✲❝♦♦r❞✐♥❛t❡ ♦❢ t❤❡ ✐♠❛❣❡ r♦✇ ✐s ❧✐♥❡❛r ❢♦r t❤✐s ❝❛s❡ ✭s❡❡ ❬✶✷❪✮✳ ❚❤✐s

❢❛❝t ✐s ✉s❡❞ ✐♥ s❡❝t✐♦♥ ✹✳✶ t♦ ❝r❡❛t❡ ❛♥ ❛rt✐✜❝✐❛❧ ❣r♦✉♥❞ ♠♦❞❡❧✳

✷✳✷✳✹ ❘❡♣r♦❥❡❝t✐♦♥

❘❡♣r♦❥❡❝t✐♦♥ ❞❡s❝r✐❜❡s t❤❡ ♣r♦❝❡ss ♦❢ ♣r♦❥❡❝t✐♥❣ ❛ ♣♦✐♥t p = [x, y]T ♦❢ ❛♥ ✐♠❛❣❡

❜❛❝❦ t♦ ❛ P♦✐♥t P ✐♥ t❤❡ t❤r❡❡✲❞✐♠❡♥s✐♦♥❛❧ ♦❜❥❡❝t ❝♦♦r❞✐♥❛t❡ s②st❡♠✳ ❆s ✇✐t❤

st❡r❡♦ ✈✐s✐♦♥ t❤❡ ❞✐st❛♥❝❡ ❜❡❝♦♠❡s ❦♥♦✇♥ t❤r♦✉❣❤ t❤❡ ❞✐s♣❛r✐t② d ❢♦r ♣✐①❡❧ p✱

P ❝❛♥ ❜❡ ❞❡t❡r♠✐♥❡❞ ❝❧❡❛r❧②✳

❚♦ ❞♦ t❤✐s✱ t❤❡ r❡♣r♦❥❡❝t✐♦♥ ♠❛tr✐① ◗ ✭❬✾✱ ♣✳ ✹✸✺❪✮ ✐s ✉s❡❞ ❛♥❞ ❛ r♦t❛t✐♦♥

♠❛tr✐① R ❡①t❡♥❞❡❞ ✇✐t❤ ❛ tr❛♥s❧❛t✐♦♥ ✈❡❝t♦r t✿

[R|t]Q

x

y

d

1

=

X

Y

Z

W

✭✻✮

Q r❡♣r♦❥❡❝ts ❛ ♣♦✐♥t p ❢r♦♠ t❤❡ ✐♠❛❣❡ ♣❧❛♥❡ t♦ ❛ ♣♦✐♥t P ✐♥ t❤❡ t❤r❡❡✲

❞✐♠❡♥s✐♦♥❛❧ ❝♦♦r❞✐♥❛t❡ ❢r❛♠❡ ♦❢ ♦❜❥❡❝ts ✐♥ ❢r♦♥t ♦❢ t❤❡ ❝❛♠❡r❛✳

Q =

1 0 0 −cx

0 1 0 −cy

0 0 0 f

0 0 −1/B (cx − c′x)/B

✭✼✮

cx✱ cy ❞❡s❝r✐❜❡ ♣r✐♥❝✐♣❛❧ ♣♦✐♥t ♦❢ t❤❡ ❧❡❢t ✐♠❛❣❡✱ ❢ ✐s t❤❡ ❝♦♠♠♦♥ ❢♦❝❛❧ ❧❡♥❣t❤

✶✶

Page 17: Obstacle detection for an autonomous model car …...a stereo vision based real-time obstacle detection system for an autonomous model car on the scale of 1:10 built for the annual

✷ ❇❛❝❦❣r♦✉♥❞ ❏❛♥♥✐s ■❤r✐❣

y1

y2

x1 x2

❋✐❣✉r❡ ✻✿ ❈❛❝❧✉❧❛t✐♥❣ t❤❡ ♣✐①❡❧ ✈❛❧✉❡ s✉♠ ❢♦r ❛ r❡❝t❛♥❣✉❧❛r r❡❣✐♦♥ ♦♥ I ✇✐t❤ t❤❡ ❤❡❧♣

♦♥ t❤❡ ✐♥t❡❣r❛❧ ✐♠❛❣❡ S✳

♦❢ ❜♦t❤ ❝❛♠❡r❛s✳ c′x ①✲❝♦♦r❞✐♥❛t❡ ♦❢ ♣r✐♥❝✐♣❛❧ ♣♦✐♥t ❢r♦♠ r✐❣❤t ✐♠❛❣❡✳ B ✐s t❤❡

①✲❝♦♠♣♦♥❡♥t ♦❢ t❤❡ tr❛♥s❧❛t✐♦♥ ✈❡❝t♦r ❜❡t✇❡❡♥ t❤❡ t✇♦ ❝❡♥t❡rs ♦❢ ♣r♦❥❡❝t✐♦♥✱

t❤❛t ✐s t❤❡ ❜❛s❡ ❧✐♥❡ ♦❢ ♦✉r st❡r❡♦ ❝❛♠❡r❛✳

[R|t] ✐s t❤❡♥ ✉s❡❞ t♦ r♦t❛t❡ ❛♥❞ tr❛♥s❧❛t❡ P ✱ ✐✳❡✳ t♦ tr❛♥s❢♦r♠ ✐t t♦ ❛ ♣♦✐♥t ✐♥

t❤❡ r❡❧❛t✐✈❡ ❝♦♦r❞✐♥❛t❡ s②st❡♠ ✉s❡❞ ❜② t❤❡ ❝❛r t♦ ♥❛✈✐❣❛t❡✳

✷✳✸ ■♥t❡❣r❛❧ ✐♠❛❣❡s

❚❤❡ ♠❡t❤♦❞ ❢♦r ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ❞❡s❝r✐❜❡❞ ✐♥ s❡❝t✐♦♥ ✹ ✇✐❧❧ ♠❛❦❡ ✐♥t❡♥s❡ ✉s❡

♦❢ ✐♥t❡❣r❛❧ ✐♠❛❣❡s ✭s❡❡ ❬✶✻❪✱ ❬✾✱ ♣✳ ✶✽✷✛❪✮✳ ❆s t❤❡ ♥❛♠❡ ✐♠♣❧✐❡s✱ s✉❝❤ ❛♥ ✐♠❛❣❡

✐s ❝r❡❛t❡❞ ❜② s✉♠♠✐♥❣ ✉♣ ♣✐①❡❧ ✈❛❧✉❡s ♦♥ ❝♦❧✉♠♥s ❛♥❞ r♦✇s ♦❢ ❛ ❣✐✈❡♥ ✐♠❛❣❡

I✳ ❚♦ ♠❛❦❡ ✐♥❞❡①✐♥❣ ♦♥ t❤❡ r❡s✉❧t✐♥❣ ✐♥t❡❣r❛❧ ✐♠❛❣❡ S ❡❛s✐❡r✱ ✐t ✐s ❤❡r❡ ❞❡✜♥❡❞

✇✐t❤ ♦♥❡ ❡①tr❛ r♦✇ ❛♥❞ ❝♦❧✉♠♥ ❝♦♠♣❛r❡❞ t♦ I✳ ❚❤❡② ❛r❡ ❛❞❞❡❞ ❛s t❤❡ ✜rst

r♦✇✴❝♦❧✉♠♥ ❛♥❞ ✜❧❧❡❞ ✇✐t❤ 0s✳ ❚❤❡ ✈❛❧✉❡ ❢♦r t❤❡ ♦t❤❡r ♣✐①❡❧s ♦♥ S t❤❡♥ ✐s

S(x, y) =i=0∑

i<x

j=0∑

j<y

I(i, j) ✭✽✮

❲✐t❤ t❤❡ ❤❡❧♣ ♦❢ S✱ t❤❡ s✉♠ ♦❢ ❛ r❡❝t❛♥❣✉❧❛r ✐♠❛❣❡ r❡❣✐♦♥ ♦❢ ❛r❜✐tr❛r② s✐③❡ ❝❛♥

❜❡ ❛❝❝❡ss❡❞ ✇✐t❤ ❛ ❝♦♥st❛♥t ♥✉♠❜❡r ♦❢ ♦♣❡r❛t✐♦♥s✿

S(x1, y1, x2, y2) = S(x2, y2)− S(x1, y2)− S(x2, y1) + S(x1, y1) ✭✾✮

❍❡r❡ x1✱ y1 ❞❡s❝r✐❜❡ t❤❡ t♦♣ ❧❡❢t ♣✐①❡❧ ♦❢ t❤❡ r❡❣✐♦♥ ❛♥❞ x2✱ y2 t❤❡ ❜♦tt♦♠ r✐❣❤t

♣✐①❡❧✱ r❡s♣❡❝t✐✈❡❧② ✭s❡❡ ✜❣✉r❡ ✻✮✳

❈❛❧❝✉❧❛t✐♥❣ t❤❡ ♠❡❛♥ ♦✈❡r S(x1y1, x2, y2) ♦♥❧② r❡q✉✐r❡s t♦ ❞✐✈✐❞❡ t❤❡ r❡tr✐❡✈❡❞

s✉♠ ❜② t❤❡ ♥✉♠❜❡r ♦❢ ♣✐①❡❧s✳

✶✷

Page 18: Obstacle detection for an autonomous model car …...a stereo vision based real-time obstacle detection system for an autonomous model car on the scale of 1:10 built for the annual

✷ ❇❛❝❦❣r♦✉♥❞ ❏❛♥♥✐s ■❤r✐❣

■❢ t❤❡ ✐♥t❡❣r❛❧ ✐♠❛❣❡ ♦✈❡r ❛♥ ✐♠❛❣❡ t❤❛t ❝♦♥t❛✐♥s ♣✐①❡❧s ✇✐t❤ ✐♥✈❛❧✐❞ ✈❛❧✉❡s

s❤♦✉❧❞ ❜❡ ❝r❡❛t❡❞ ✹✱ t❤❡s❡ ✈❛❧✉❡s ❝❛♥ ❜❡ ✜❧❧❡❞ ✇✐t❤ 0s ❢♦r t❤❡ ❝♦♠♣✉t❛t✐♦♥✳

❖❜t❛✐♥✐♥❣ t❤❡ ♠❡❛♥ ♦✈❡r t❤❡ ✈❛❧✉❡s ♦❢ ❛ r❡❣✐♦♥ t❤❡♥ r❡q✉✐r❡s t❤❡ ❦♥♦✇❧❡❞❣❡ ♦❢

t❤❡ ♥✉♠❜❡r ♦❢ ✈❛❧✐❞ ♣✐①❡❧s ✐♥ t❤❛t r❡❣✐♦♥✳ ❚♦ s♦❧✈❡ t❤✐s ♣r♦❜❧❡♠✱ t❤❡ ❛♣♣r♦❛❝❤

✉s❡❞ ❤❡r❡ ✐s t♦ ❝r❡❛t❡ ❛ s❡❝♦♥❞ ✐♥t❡❣r❛❧ ✐♠❛❣❡ t♦❣❡t❤❡r ✇✐t❤ t❤❡ ✜rst✳ ❊❛❝❤

✈❛❧✐❞ ♣✐①❡❧ ✐s ✐♥t❡r♣r❡t❡❞ ❛s 1✱ ❡❛❝❤ ✐♥✈❛❧✐❞ ❛s 0✳ ❚❤❡ s✉♠ ♦✈❡r t❤❡ ✈❛❧✉❡s ♦❢ ❛

r❡❣✐♦♥ t❤❡♥ r❡s✉❧ts ✐♥ t❤❡ s✉♠ ♦❢ ✐ts ❝♦♥t❛✐♥❡❞ ✈❛❧✐❞ ♣✐①❡❧s✳

✷✳✹ ❙❝❛❧❡ ❛♥❞ ✐♠❛❣❡ ♣②r❛♠✐❞s

■♥ ❬✶✵✱ ♣✳ ✶✻✻❪ s❝❛❧❡ ✐s ❞❡s❝r✐❜❡❞ ❛s

❙❝❛❧❡ ✐s s✐♠♣❧② t❤❡ ♠❛♥✐❢❡st❛t✐♦♥ ♦❢ ❛ ❝❤❛♥❣❡ ✐♥ t❤❡ s♣❛t✐❛❧ s✐③❡✱

♦r s❝❛❧❡✱ ♦❢ ❛ ❢❡❛t✉r❡✱ r❡❣✐♦♥ ♦r ❝♦♠♣❧❡t❡ ❣r♦✉♣✐♥❣ ✭❡✳❣✳ ♦❜❥❡❝t ♦❢

✐♥t❡r❡st✮✳ ■♥ t❤❡ ❝❛s❡ ♦❢ ❛ r❡❛❧ ❝❛♠❡r❛ s②st❡♠✱ ❛ ❝❤❛♥❣❡ ✐♥ s❝❛❧❡

♦❢ t❤❡ ♣r♦❥❡❝t❡❞ ✐♠❛❣❡ ♦❢ ❛♥ ♦❜❥❡❝t ✐♥ t❤❡ r❡❛❧ ✇♦r❧❞ ✐s t②♣✐❝❛❧❧②

❝❛✉s❡❞ ❜② t❤❡ ❞✐st❛♥❝❡ ❢r♦♠ t❤❡ ❝❛♠❡r❛ t♦ t❤❡ ♦❜❥❡❝t ❝❤❛♥❣✐♥❣✳

❬✳✳✳❪ ❆s ✇❡ ❛♣♣r♦❛❝❤ t❤✐s ♦❜❥❡❝t✱ ✐ts ♣r♦❥❡❝t✐♦♥ ✇✐❧❧ ❣r♦✇ ✐♥ s✐③❡

♦♥ t❤❡ ✐♠❛❣✐♥❣ ♣❧❛♥❡ ❛♥❞ ❛ ❝♦rr❡s♣♦♥❞✐♥❣❧② ❧❛r❣❡r r❛♥❣❡ ♦❢ s♣❛t✐❛❧

❢r❡q✉❡♥❝✐❡s ♠❛② ❜❡ ♣r❡s❡♥t t♦ ❞❡s❝r✐❜❡ ♠♦r❡ ❵❞❡t❛✐❧✬ ♦♥ t❤❡ s✉r❢❛❝❡

♦❢ t❤❡ ♦❜❥❡❝t✳

❚❤✐s ❞❡s❝r✐♣t✐♦♥ s✉❣❣❡sts t❤❡ ✐❞❡❛ t♦ ✜rst ✐♥s♣❡❝t ❛♥ ✐♠❛❣❡ ♦♥ ❛ ❤✐❣❤❡r s❝❛❧❡

❛♥❞ ♦♥❧② ❞❡s❝❡♥❞ ✐♥t♦ r❡❣✐♦♥s ♦❢ ✐♥t❡r❡st✳ ❚♦ ❞♦ t❤✐s✱ ❛ ❞❛t❛ str✉❝t✉r❡ t❤❛t

r❡♣r❡s❡♥ts ❛ s✐♥❣❧❡ ✐♠❛❣❡ ♦♥ ♠✉❧t✐♣❧❡ s❝❛❧❡s ✐s ♥❡❡❞❡❞✳

■♠❛❣❡ ♣②r❛♠✐❞s ❝❛♥ ❜❡ ✉s❡❞ t♦ ✐♥s♣❡❝t t❤❡ ❢❡❛t✉r❡s ♦❢ ♦♥❡ ✐♠❛❣❡ ♦♥ ♠✉❧t✐♣❧❡

s❝❛❧❡s ✭❬✺❪✱ ❬✾✱ ♣✳ ✶✸✵✛❪✮✳ ❚❤❡② ❝♦♥s✐st ♦❢ ❛ s❡t ♦❢ ✐♠❛❣❡s ❞❡r✐✈❡❞ ❢r♦♠ ♦♥❡

s♦✉r❝❡ ✐♠❛❣❡✳ ▲❡t l ❜❡ t❤❡ ❧❡✈❡❧ ♦❢ ❛♥ ✐♠❛❣❡ ❛♥❞ I0 t❤❡ s♦✉r❝❡ ✐♠❛❣❡✳ ❊❛❝❤

❢✉rt❤❡r ✐♠❛❣❡ Il ✐s ❞❡r✐✈❡❞ ❢r♦♠ Il−1 ❜② ❛♣♣❧②✐♥❣ ❛ ✜❧t❡r ❛♥❞ s✉❜✲s❛♠♣❧✐♥❣✳ ■♥

❬✾❪✱ t❤❡ s✉❜✲s❛♠♣❧✐♥❣ ✐s ❞♦♥❡ ❜② r❡♠♦✈✐♥❣ ❡❛❝❤ ❡✈❡♥ r♦✇ ❛♥❞ ❝♦❧✉♠♥ ❢r♦♠ Il−1

t♦ ❝r❡❛t❡ Il✳ ❚❤✐s ❤❛s t❤❡ ❡✛❡❝t t❤❛t Il−1 ✐s ♦♥❡✲q✉❛rt❡r t❤❡ s✐③❡ ♦❢ Il✳

❚❤❡ ❛♣♣r♦❛❝❤ ✐♥ s❡❝t✐♦♥ ✹ ♠❛❦❡s ✉s❡ ♦❢ s✐♠✐❧❛r ❜✉t s✐♠♣❧❡r ✐♠❛❣❡ ♣②r❛♠✐❞s

❞❡✈❡❧♦♣❡❞ ❢♦r t❤✐s ✇♦r❦✳ ❚❤❡② ❛r❡ ❞❡r✐✈❡❞ ❢r♦♠ ❛♥ ✐♠❛❣❡ I s♦❧❡❧② ❜② ❝❛❧❝✉❧❛t✐♥❣

♣✐①❡❧ ✈❛❧✉❡ ♠❡❛♥s ❢♦r ✐♠❛❣❡ ❛r❡❛s✳ ❆♥ ✐♥t❡❣r❛❧ ✐♠❛❣❡ S ♦❢ I ❤❡❧♣s t♦ ❞♦ t❤✐s

❡✣❝✐❡♥t❧②✳

✹❋♦r ❡①❛♠♣❧❡ ❛ s♣❛rs❡ ❞✐s♣❛r✐t② ♠❛♣✳

✶✸

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✷ ❇❛❝❦❣r♦✉♥❞ ❏❛♥♥✐s ■❤r✐❣

I0

I1

I

Image Image pyramid

I2

❋✐❣✉r❡ ✼✿ ❚♦♣ ♦❢ ❛♥ ✐♠❛❣❡ ♣②r❛♠✐❞ ♦❢ ✐♠❛❣❡ ■✳ ❚❤❡ ✈❛❧✉❡ ♦❢ t❤❡ ❤✐❣❤❧✐❣❤t❡❞ ♣✐①❡❧s

♦♥ ♦♥ I1 ❛♥❞ I2 ❝♦rr❡s♣♦♥❞ t♦ t❤❡ ♠❡❛♥ ♣✐①❡❧ ✈❛❧✉❡ ♦❢ t❤❡ ❤✐❣❤❧✐❣❤t❡❞ r❡❣✐♦♥ ♦♥ I✳

❚❤❡ ❝r❡❛t✐♦♥ ♦❢ t❤❡ s✐♥❣❧❡ ✐♠❛❣❡s st❛rts ❢r♦♠ t❤❡ t♦♣ ♦❢ t❤❡ ♣②r❛♠✐❞✳ ❋♦r ❛♥

✐♠❛❣❡ Il ❛ 2l × 2l ❣r✐❞ ✐s ♣❧❛❝❡❞ ♦✈❡r S ❛♥❞ t❤❡ ♠❡❛♥ ♣✐①❡❧ ✈❛❧✉❡ ✐s ❝❛❧❝✉❧❛t❡❞

❢♦r t❤❡ ✉♥❞❡r❧②✐♥❣ ✐♠❛❣❡ r❡❣✐♦♥ ♦❢ ❡❛❝❤ ❝❡❧❧✳ ❍❡r❡ I0 ❞♦❡s ♥♦t ♥❛♠❡ t❤❡ s♦✉r❝❡

✐♠❛❣❡✳ ■♥st❡❛❞ ✐t ✐s ❛ 1 × 1 ♣✐①❡❧ ✐♠❛❣❡ t❤❛t ✐s ❝r❡❛t❡❞ ❜② ❝❛❧❝✉❧❛t✐♥❣ t❤❡

♠❡❛♥ ♦✈❡r t❤❡ ✇❤♦❧❡ ✐♠❛❣❡ S✳ ❚❤❡ ❝r❡❛t✐♦♥ ♦❢ ❡❛❝❤ ❢♦❧❧♦✇✐♥❣ ✐♠❛❣❡ ❝❛♥ ❜❡

✐♥t❡r♣r❡t❡❞ ❛s s♣❧✐tt✐♥❣ ❡❛❝❤ ❝❡❧❧ ✐♥t♦ ❢♦✉r s✉❜✲❝❡❧❧s ❛♥❞ ❝❛❧❝✉❧❛t✐♥❣ t❤❡ r❡❧❛t❡❞

♣✐①❡❧ ✈❛❧✉❡ ♠❡❛♥s✳ ❚❤✉s t❤❡ r❡❧❛t✐♦♥ ❜❡t✇❡❡♥ Il ❛♥❞ Il−1 t❤❛t t❤❡ ✜rst ✐s ♦♥❡✲

q✉❛rt❡r t❤❡ s✐③❡ ♦❢ t❤❡ s❡❝♦♥❞ r❡♠❛✐♥s✳ ❚❤❡ r❡s✉❧t✐♥❣ str✉❝t✉r❡ r❡s❡♠❜❧❡s ❛

❜♦tt♦♠ ✉♣ ♣②r❛♠✐❞✳

❚♦ ♠❛❦❡ ♥❛✈✐❣❛t✐♦♥ ♦♥ t❤❡ ✐♠❛❣❡ ♣②r❛♠✐❞ ❡❛s✐❡r✱ ❛ ♣❛r❡♥t✲❝❤✐❧❞r❡♥ r❡❧❛t✐♦♥

❜❡t✇❡❡♥ t❤❡ ♣✐①❡❧ r❡s✉❧t✐♥❣ ❢r♦♠ ❛ ❝❡❧❧ ♦♥ Il−1 ❛♥❞ t❤❡ ❢♦✉r s✉❜✲♣✐①❡❧s r❡s✉❧t✐♥❣

❢r♦♠ t❤❡ ♥❡✇ s✉❜✲❝❡❧❧s ♦♥ Il ✐s ❝r❡❛t❡❞✳ ❚❤❡ ♣❛r❡♥t ❢♦r ❛ ♣✐①❡❧ Il(x, y) ✐s ❝❛❧❧❡❞

parent(Il(x, y))✳ ❚❤❡ s❡t ♦❢ t❤❡ ❝❤✐❧❞r❡♥ ♦❢ Il(x, y) ♦r❞❡r❡❞ ❢r♦♠ t♦♣ ❧❡❢t t♦

❜♦tt♦♠ r✐❣❤t ✇✐❧❧ ❜❡ ❞❡♥♦t❡❞ ✇✐t❤ children(Il(x, y))✳ ■♥ ❡q✉❛t✐♦♥s✱ Il(x, y)

✇✐❧❧ ❛❧s♦ st❛♥❞ ❢♦r t❤❡ ✈❛❧✉❡ ♦❢ t❤❡ ♣✐①❡❧✳

❖♥❡ ♣✐①❡❧ Il(x, y) ❛❧✇❛②s r❡s✉❧ts ❢r♦♠ ❛ r❡❝t❛♥❣✉❧❛r r❡❣✐♦♥ ♦♥ S ❛♥❞ ❤❛s t❤❡

♠❡❛♥ ♣✐①❡❧ ✈❛❧✉❡ ❢♦r t❤❡ s❛♠❡ r❡❣✐♦♥ ♦♥ I✳ ❚❤✐s r❡❣✐♦♥ ✐s s✉❜s❡q✉❡♥t❧② ❝❛❧❧❡❞

patch(Il(x, y))✳ ❚❤❡ r❡❧❛t✐♦♥ ❜❡t✇❡❡♥ t❤❡ s✐♥❣❧❡ ♣✐①❡❧s ♦♥ t❤❡ ✐♠❛❣❡s ♦❢ t❤❡

♣②r❛♠✐❞ ✇✐❧❧ ❜❡ ✉s❡❞ t♦ ❡✣❝✐❡♥t❧② ❞❡❞✉❝❡ st❛t❡♠❡♥ts ♦✈❡r ♣❛t❝❤❡s ♦❢ I ❡✣✲

❝✐❡♥t❧②✳

✶✹

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✸ ❚❤❡ P❧❛t❢♦r♠ ❏❛♥♥✐s ■❤r✐❣

✸ ❚❤❡ P❧❛t❢♦r♠

❚❤✐s s❡❝t✐♦♥ ✇✐❧❧ ❞❡s❝r✐❜❡ t❤❡ ♣❧❛t❢♦r♠ ❝♦♥s✐st✐♥❣ ♦❢ s♦❢t✲ ❛♥❞ ❤❛r❞✇❛r❡ ✉s❡❞

❜② t❤❡ ❇❡r❧✐♥ ❯♥✐t❡❞ ❘❛❝✐♥❣ ❚❡❛♠✳ ■t ✜rst ❢♦❝✉s❡s ♦♥ ✐ts st❛t❡ ❜❡❢♦r❡ t❤✐s

✇♦r❦ t❤❛t ✐s st✐❧❧ ♠❛✐♥t❛✐♥❡❞ ❢♦r ❆❜❧❡ ❛♥❞ ✇✐❧❧ t❤❡♥ ♣r❡s❡♥t t❤❡ ❝❤❛♥❣❡s ♠❛❞❡

t♦ ❇❛❝❦❡r t❤❛t ❛✐♠ ❛t ✐♥t❡❣r❛t✐♥❣ ❛ st❡r❡♦ ❝❛♠❡r❛ ✐♥t♦ t❤❡ ♣❧❛t❢♦r♠✳

❋✐❣✉r❡ ✽✿ ❆❜❧❡ t♦ t❤❡ ❧❡❢t ❛♥❞ ❇❛❦❡r t♦ t❤❡ r✐❣❤t✳ ❇♦t❤ ✇❤❡r❡ ✐❞❡♥t✐❝❛❧ ✐♥

❝♦♥str✉❝t✐♦♥ ❜❡❢♦r❡ ❇❛❦❡rs ❤❛r❞✇❛r❡ ✇❛s ❡①t❡♥❞❡❞ ❢♦r ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥✳

✸✳✶ ❋♦r♠❡r P❧❛t❢♦r♠

❚❤❡ ❜❛s✐❝ ❝♦♥❝❡♣t ❢♦r ❜♦t❤ ❝❛rs ✇❛s ❞❡✈❡❧♦♣❡❞ ❢♦r t❤❡ ❈❛r♦❧♦✲❈✉♣ ✷✵✶✷ ❜②

❏❛♥ ❇♦❧❞t ❛♥❞ ❙❡✈❡r✐♥ ❏✉♥❦❡r ❬✽❪✳ ❚❤❡ ❤❛r❞✇❛r❡ ✐s ❜❛s❡❞ ♦♥ ❛ ❝♦♠♠♦♥ r❛❞✐♦

❝♦♥tr♦❧❧❡❞ ♠♦❞❡❧ ❝❛r ♦♥ t❤❡ s❝❛❧❡ ♦❢ ✶✿✶✵ t❤❛t ✇❛s ❝❤♦s❡♥ ❢♦r ✐ts r♦❜✉st♥❡ss✳

❆♥ ❖❞r♦✐❞✲❳✷ ✇❛s s❡❧❡❝t❡❞ ❛s t❤❡ ❝❡♥tr❛❧ ♣r♦❝❡ss♦r✱ ❤❛♥❞❧✐♥❣ ❛❧❧ ❤✐❣❤❡r ❧❡✈❡❧

❝♦♠♣✉t❛t✐♦♥ s✉❝❤ ❛s ✐♠❛❣❡ ♣r♦❝❡ss✐♥❣✱ ❜❡❤❛✈✐♦r ❛♥❞ ❞r✐✈✐♥❣ ❝♦♥tr♦❧✳ ❆ s❡♣✲

❛r❛t❡ ♠✐❝r♦ ❝♦♥tr♦❧❧❡r ❜♦❛r❞ ❝❛❧❧❡❞ ❖tt♦❱✷ ❝♦♥tr♦❧s t❤❡ st❡❡r✐♥❣ s❡r✈♦s✱ t❤❡

♠♦t♦r ❛♥❞ ❛♥ ✐♥♣✉t ♣❛♥❡❧ ❛t t❤❡ ❜❛❝❦ ♦❢ t❤❡ ❝❛r✳ ■t ✇❛s s♣❡❝✐✜❝❛❧❧② ❞❡✈❡❧✲

♦♣❡❞ ❜② t❤❡ t❡❛♠✱ ❛❧♦♥❣s✐❞❡ t❤❡ P♦✇❡r❜♦❛r❞ t❤❛t ♣♦✇❡rs t❤❡ ♣❧❛t❢♦r♠ ✇✐t❤

✶✺

Page 21: Obstacle detection for an autonomous model car …...a stereo vision based real-time obstacle detection system for an autonomous model car on the scale of 1:10 built for the annual

✸ ❚❤❡ P❧❛t❢♦r♠ ❏❛♥♥✐s ■❤r✐❣

✺❱ ❢r♦♠ ❛ ❧✐t❤✐✉♠ ♣♦❧②♠❡r ❛❝❝✉♠✉❧❛t♦r✳ ❚❤❡ ♠♦t♦r ✐s ❛ ❋❛✉❧❤❛❜❡r ✸✵✺✻ ✵✶✷

❇✲❑✶✶✺✺ ❡❧❡❝tr♦ ♠♦t♦r✳ ■t ❛❧❧♦✇s ✜♥❡ ❝♦♥tr♦❧ ♦❢ ✈❡❧♦❝✐t② ✐♥ ❝♦♠❜✐♥❛t✐♦♥ ✇✐t❤

t❤❡ ❋❛✉❧❤❛❜❡r ▼❈❇▲ ✸✵✵✻ ❙ ❘❙ ♠♦t♦r ❝♦♥tr♦❧❧❡r✳

❙♦ ❢❛r✱ ❛♥ ♦♠♥✐✲❞✐r❡❝t✐♦♥❛❧ ❝❛♠❡r❛✱ ❜✉✐❧❞ ❜② ❢❛❝✐♥❣ ❛ ❝♦♥✈❡♥t✐♦♥❛❧ ✇❡❜✲❝❛♠

✉♣ ♦♥t♦ ❛ ❝♦♥✈❡① ♠✐rr♦r✱ ✐s t❤❡ ♦♥❧② s❡♥s♦r ❛✈❛✐❧❛❜❧❡✳ ❚❤✐s ♦♠♥✐✲❞✐r❡❝t✐♦♥❛❧

❝❛♠❡r❛ ✐s ❛tt❛❝❤❡❞ t♦ t❤❡ t♦♣ ♦❢ ❛ s❡♥s♦r ♣♦❧❡ ❛t t❤❡ ❝❛r✬s ❝❡♥t❡r✳ ❚❤❡ t♦t❛❧

❤❡✐❣❤t ♦❢ t❤❡ ❝❛r ✐s ❧✐♠✐t❡❞ t♦ ✸✵ ❝♠ ❜② ❈❛r♦❧♦✲❈✉♣ r✉❧❡s✳ ❚❤❡ ❝❛♠❡r❛ ❛❧❧♦✇s ❢♦r

✸✻✵ ❞❡❣r❡❡ ✈✐s✐♦♥ ❛♥❞ t❤❡r❡❢♦r❡ t♦ ♣❡r❝❡✐✈❡ s✉rr♦✉♥❞✐♥❣s ♦❢ t❤❡ ❝❛r ✐♥ ♦♥❡ s✐♥❣❧❡

❢r❛♠❡✳ ❆t t❤❡ ❞♦✇♥s✐❞❡✱ s✐❣❤t ✐s ❧✐♠✐t❡❞ t♦ r♦✉❣❤❧② ✶✳✺ ♠ ✐♥ ❡❛❝❤ ❞✐r❡❝t✐♦♥ ❛♥❞

❤✐❣❤ ❞✐st♦rt✐♦♥ ❛❞❞✐t✐♦♥❛❧❧② r❡❞✉❝❡s t❤❡ q✉❛❧✐t② ♦❢ ♣✐❝t✉r❡s ❛t ❢❛r ❞✐st❛♥❝❡s✳

❚❤❡ s♦❢t✇❛r❡ ✉s❡❞ ✐s ❜❛s❡❞ ♦♥ t❤❡ ❇❡r❧✐♥ ❯♥✐t❡❞ ❢r❛♠❡✇♦r❦ ✉s❡❞ ✐♥ ♠✉❧t✐♣❧❡

♣r♦❥❡❝ts ❛t t❤❡ ❆■ ❞❡♣❛rt♠❡♥t ♦❢ t❤❡ ❋r❡✐❡ ❯♥✐✈❡rs✐tät ❇❡r❧✐♥ ❛♥❞ ❡①t❡♥❞❡❞ ❜②

♠♦❞✉❧❡s ✇r✐tt❡♥ ❜② t❤❡ ♠❡♠❜❡rs ♦❢ ❇❡r❧✐♥ ❯♥✐t❡❞ ❘❛❝✐♥❣ ❚❡❛♠✳ ▼♦♥✐t♦r✐♥❣

t❤❡ ❝❛r✱ str❡❛♠✐♥❣ s❡♥s♦r ❞❛t❛ ❛♥❞ ❞❡❜✉❣❣✐♥❣ s♦❢t✇❛r❡ ❝❛♥ ❜❡ ❞♦♥❡ r❡♠♦t❡❧②

❜② ✉s✐♥❣ ❛ t♦♦❧ ❝❛❧❧❡❞ ❋❯r❡♠♦t❡✳

✸✳✷ ■♥tr♦❞✉❝❡❞ ❈❤❛♥❣❡s

❆s st❛t❡❞ ✐♥ t❤❡ ♣r♦❜❧❡♠ ❞❡s❝r✐♣t✐♦♥ ✐♥ s❡❝t✐♦♥ ✶✳✸✱ t❤❡ ❝❛r ❤❛s t♦ ❜❡ ❡①t❡♥❞❡❞

✇✐t❤ ❛ ❞❡♣t❤ s❡♥s♦r✳ ❋♦r t❤✐s✱ ❛ st❡r❡♦ ❝❛♠❡r❛ ✇❛s s❡❧❡❝t❡❞✱ ❛s ✐t ❛❧❧♦✇s

t♦ ♣❡r❝❡✐✈❡ ❞❡♣t❤ ✐♥❢♦r♠❛t✐♦♥ ❢♦r ❛♥ ✇❤♦❧❡ ❛r❡❛ ✐♥ ❢r♦♥t ♦❢ t❤❡ ❝❛r ❛t ❤✐❣❤

❢r❡q✉❡♥❝② ❛♥❞ ✇✐t❤ ❤✐❣❤ ❛❝❝✉r❛❝②✳ ❆t t❤❡ s❛♠❡ t✐♠❡✱ t❤❡ ♥❡✇ ❝❛♠❡r❛ ✇✐❧❧

❝♦♠♣❧❡♠❡♥t t❤❡ ❡①✐st✐♥❣ ♦♠♥✐✲❞✐r❡❝t✐♦♥❛❧ ❝❛♠❡r❛ ❜② ❤❛✈✐♥❣ ❛ ♠✉❝❤ ❤✐❣❤❡r

r❛♥❣❡ ♦❢ ✈✐s✐♦♥ ❛♥❞ ❧♦✇ ❞✐st♦rt✐♦♥✳ ❚❤❡ s❡❧❡❝t❡❞ ❱✐s❦♦s✲❙♠❛rt❈❛♠ ✇✐❧❧ ❜❡

❞❡s❝r✐❜❡❞ ✐♥ s❡❝t✐♦♥ ✸✳✷✳✶✳ ■ts ✐♥t❡❣r❛t✐♦♥ ✇✐t❤ t❤❡ ❡①✐st✐♥❣ ❤❛r❞✇❛r❡ ♠❛❦❡s

❢✉rt❤❡r ❤❛r❞✇❛r❡ ❝❤❛♥❣❡s ♥❡❝❡ss❛r② ✇❤✐❝❤ ✇✐❧❧ ❜❡ ❞❡s❝r✐❜❡❞ ✐♥ s❡❝t✐♦♥ ✸✳✷✳✷✳

✸✳✷✳✶ ❙t❡r❡♦ ❝❛♠❡r❛

❚❤❡ ✐♥tr♦❞✉❝t✐♦♥ ♦❢ ❛ ❱✐s❑♦s✲❙♠❛rt❈❛♠ ✐t t❤❡ ♠♦st ✐♠♣♦rt❛♥t ❤❛r❞✇❛r❡

❝❤❛♥❣❡ ❞♦♥❡ t♦ ❇❛❦❡r✳ ■t ❝♦♥s✐sts ♦❢ ❛ ❊♥❝❧✉str❛ ❜♦❛r❞ ❤♦st✐♥❣ ❛ ❆❘▼ ❈♦rt❡①✲

❆✼ ❛♥❞ ❛ ❋P●❆ ✉s❡❞ ❢♦r ♣❛r❛❧❧❡❧ ✐♠❛❣❡ ♣r♦❝❡ss✐♥❣ ❞✉r✐♥❣ st❡r❡♦ ♠❛t❝❤✐♥❣✳ ■t

✐s ❛tt❛❝❤❡❞ t♦ ❛ ❝❛rr✐❡r ❜♦❛r❞ t❤❛t ♣r♦✈✐❞❡ ♦♥❡ ❯❙❇ ✷✳✵ ❛♥❞ ♦♥❡ ❘❏✹✺ s♦❝❦❡t

❛s ✇❡❧❧ ♦♥❡ ♠✐❝r♦❙❉ s❧♦t✳ ❚❤❡s❡ t✇♦ ❜♦❛r❞s ❛r❡ ♣❧❛❝❡❞ ♦♥ t❤❡ ♠❛✐♥ ❝❛rr✐❡r

❜♦❛r❞ ♦❢ t❤❡ ❝❛r✳

✶✻

Page 22: Obstacle detection for an autonomous model car …...a stereo vision based real-time obstacle detection system for an autonomous model car on the scale of 1:10 built for the annual

✸ ❚❤❡ P❧❛t❢♦r♠ ❏❛♥♥✐s ■❤r✐❣

❚❤❡ ❛❝t✉❛❧ st❡r❡♦ r❛❝❦ ❝♦♥s✐sts ♦❢ t✇♦ s❡♥s♦rs ❛♥❞ ❝♦rr❡s♣♦♥❞✐♥❣ ❧❡♥s❡s ❛t✲

t❛❝❤❡❞ t♦ ❛ s♦❧✐❞ ❜❧♦❝❦ ♦❢ ❛❧✉♠✐♥✉♠ t♦ ♣r❡s❡r✈❡ t❤❡✐r ❛❧✐❣♥♠❡♥t✳ ❚❤❡ ❝✉rr❡♥t

s❡t✉♣ r❡s✉❧ts ✐♥ ❛ ❜❛s❡ ❧✐♥❡ ♦❢ ✵✳✵✼✸ ♠ ❢♦r t❤❡ st❡r❡♦ ❝❛♠❡r❛✳ ❚❤❡ ♣♦ss✐❜✐❧✲

✐t② t♦ ❛❞❥✉st t❤❡ ❜❛s❡ ❧✐♥❡ ❛❧❧♦✇❡❞ t♦ ✜t t❤❡ ❝❛♠❡r❛ ♦♥t♦ t❤❡ ♣❧❛t❢♦r♠ ✇❤✐❧❡

❦❡❡♣✐♥❣ t❤❡ ❞✐♠❡♥s✐♦♥s ♦❢ t❤❡ ❝❛r ❝♦♥❢♦r♠ t♦ t❤❡ ❈❛r♦❧♦✲❈✉♣ r✉❧❡s✳ ▼♦r❡♦✈❡r✱

t❤❡ s♠❛❧❧ ❜❛s❡ ❧✐♥❡ ✐♥✢✉❡♥❝❡s t❤❡ ✸❉ ❛r❡✱ ✐♥ ✇❤✐❝❤ t❤❡ st❡r❡♦ ❝❛♠❡r❛ ✐s ❛❜❧❡

t♦ r❡s♦❧✈❡ ❞✐s♣❛r✐t✐❡s✳ ❲✐t❤ t❤❡ ❝✉rr❡♥t ❧❡♥s❡s t❤❛t ❤❛✈❡ ❛ ❢♦❝❛❧ ❧❡♥❣t❤ ♦❢ ✸✱✺

♠♠✱ t❤✐s ❛❧❧♦✇s t♦ r❡s♦❧✈❡ ❞✐s♣❛r✐t✐❡s ❢♦r ♦❜❥❡❝ts t❤❛t ❛r❡ ❛s ❝❧♦s❡ ❛s ✵✳✺ ♠✳

❚❤❡ st❡r❡♦ r❛❝❦ ✐s ♣❧❛❝❡❞ ♦♥ t❤❡ s❡♥s♦r ♣♦❧❡ ✉♥❞❡r♥❡❛t❤ t❤❡ ♦♠♥✐✲❞✐r❡❝t✐♦♥❛❧

❝❛♠❡r❛ ❢❛❝✐♥❣ t❤❡ ❞r✐✈✐♥❣ ❞✐r❡❝t✐♦♥✳ ❚❤✐s r❡s✉❧ts ✐♥ ❛ ❝❛♠❡r❛ ❤❡✐❣❤t ✶✻ ❝♠

♦✈❡r t❤❡ ❣r♦✉♥❞✳ ■t ✐s s✉❜s❡q✉❡♥t❧② ❛ss✉♠❡❞ t❤❛t t❤❡ ♦♣t✐❝❛❧ ❛①❡s ♦❢ t❤❡ st❡r❡♦

❝❛♠❡r❛ ❛r❡ ❡①❛❝t❧② ♣❛r❛❧❧❡❧ t♦ t❤❡ ♠❛❥♦r ❛①✐s ♦❢ t❤❡ ❝❛r✳

❋✐❣✉r❡ ✾✿ ❚❤❡ ❱✐s❑♦s✲❙♠❛rt❈❛♠ ✉s❡❞ ✐♥ ❇❛❦❡r✳

❚❤❡ ❝❛♠❡r❛ ❞❡❧✐✈❡rs ✷✵ ❢r❛♠❡s ♣❡r s❡❝♦♥❞ ❛♥❞ ✐s ❝❛♣❛❜❧❡ t♦ ♠❡❛s✉r❡ ❞❡♣t❤

✇✐t❤ s✉❜✲❞✐s♣❛r✐t② ❛❝❝✉r❛❝②✳ ❚❤❡ ❝❛♠❡r❛ ✐s r✉♥♥✐♥❣ ❛ ▲✐♥❛r♦✲♥❛♥♦ ▲✐♥✉① ❛♥❞

✐s ❝♦♥♥❡❝t❡❞ t♦ t❤❡ ❝❡♥tr❛❧ ♣r♦❝❡ss♦r ✈✐❛ ❊t❤❡r♥❡t✳ ■♥ t❤❡ ❝✉rr❡♥t ❝♦♥✜❣✉r❛✲

t✐♦♥✱ ✐t s❡♥❞s t❤❡ ❧❡❢t ❝❛♠❡r❛ ✐♠❛❣❡ ❛♥❞ t❤❡ ❞✐s♣❛r✐t② ♠❛♣ ❛s ❛ str❡❛♠ ♦❢ ❯❉P

♣❛❝❦❛❣❡s✳ ❚❤❡ ❧❡❢t ❝❛♠❡r❛ ✐♠❛❣❡ ✇✐❧❧ ♥♦t ❜❡ ♥❡❡❞❡❞ ❢♦r t❤❡ ✐♠♣❧❡♠❡♥t❡❞ ♦❜✲

st❛❝❧❡ ❞❡t❡❝t✐♦♥ ❜✉t ✐s ♣r♦✈✐❞❡❞ ❢♦r ❢✉t✉r❡ ✉s❡✳ P♦✇❡r ✐s s✉♣♣❧✐❡❞ ❜② ❝♦♥♥❡❝t✐♥❣

✐t ✇✐t❤ t❤❡ ❝❡♥tr❛❧ ♣r♦❝❡ss♦r ♦✈❡r ❯❙❇✳

✸✳✷✳✷ ❉❡♣❡♥❞❡♥t ❝❤❛♥❣❡s

❚❤❡ ✶✵✵▼❜✐t✴s ❊t❤❡r♥❡t ❝♦♥♥❡❝t✐♦♥ ❛✈❛✐❧❛❜❧❡ ✇✐t❤ t❤❡ ❖❞r♦✐❞✲❳✷ s♦ ❢❛r ❞♦❡s

♥♦t ♣r♦✈✐❞❡ ❜❛♥❞✇✐❞t❤ ♥❡❝❡ss❛r② t♦ r❡❝❡✐✈❡ ❛ ✽ ❜✐t✴♣✐①❡❧ ❛♥❞ ❛ ✶✻ ❜✐t✴♣✐①❡❧

✐♠❛❣❡ ✇✐t❤ ❛♥ ✐♠❛❣❡ r❡s♦❧✉t✐♦♥ ♦❢ 752× 480 ❛t ✷✵ ❍③✳ ❚♦ s♦❧✈❡ t❤✐s ♣r♦❜❧❡♠✱

t❤❡ ❖❞r♦✐❞✲❳✷ ✐s r❡♣❧❛❝❡❞ ❜② t❤❡ ♥❡✇❡r ❖❞r♦✐❞✲❳❯ ✇❤✐❝❤ ❤❛s ❛ ❯❙❇ ✸✳✵ ♣♦rt✳

✶✼

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✹ ❖❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ❏❛♥♥✐s ■❤r✐❣

❆ ❯❙❇ ✸✳✵ t♦ ●✐❣❛❜✐t ❊t❤❡r♥❡t ❛❞❛♣t❡r ✐s t❤❡♥ ✉s❡❞ t♦ ❝♦♥♥❡❝t ❝❛♠❡r❛ ❛♥❞

❝❡♥tr❛❧ ♣r♦❝❡ss♦r✳

❚❤❡ ♣♦✇❡r ❝♦♥s✉♠♣t✐♦♥ ♦❢ t❤❡ ♥❡✇ st❡r❡♦ ❝❛♠❡r❛ ❛♥❞ t❤❡ ❖❞r♦✐❞✲❳❯ ❡①❡❡❞

t❤❡ ✷ ❆ ♣r♦✈✐❞❡❞ ❜② t❤❡ ❝✉rr❡♥t P♦✇❡r❜♦❛r❞✳ ❚❤❡r❡❢♦r❡✱ ❛ ♥❡✇ ✈❡rs✐♦♥ ♦❢ t❤❡

P♦✇❡r❜♦❛r❞ ✐s ✉♥❞❡r ❞❡✈❡❧♦♣♠❡♥t ✇❤✐❝❤ ✇✐❧❧ ♣♦✇❡r ❞❡✈✐❝❡s ✉♣ t♦ ✻ ❆✳

❚❤❡ ❇❡r❧✐♥ ❯♥✐t❡❞ ❢r❛♠❡ ✇♦r❦ ❤❛s ❜❡❡♥ ❡①t❡♥❞❡❞ ✐♥ ❛ ✇❛② t❤❛t t❤❡ ❯❉P

♣❛❝❦❛❣❡s s❡♥❞ ❢r♦♠ t❤❡ st❡r❡♦ ❝❛♠❡r❛ ❛r❡ r❡❝❡✐✈❡❞✳ ❚❤❡ ✐♠❛❣❡s ❝❛♥ ♥♦✇ ❜❡

♣r♦✈✐❞❡❞ t♦ ❛♥② ♥✉♠❜❡r ♦❢ ❛❞❞✐t✐♦♥❛❧ ♠♦❞✉❧❡s ❡①t❡♥❞✐♥❣ t❤❡ s♦❢t✇❛r❡ ❛♥❞

❛❧s♦ str❡❛♠❡❞ t♦ t❤❡ ❋❯r❡♠♦t❡✳ ❉✐s♣❛r✐t② ♠❛♣s ❛r❡ ✈✐s✉❛❧✐③❡❞ ❢♦r str❡❛♠✐♥❣

✇✐t❤ t❤❡ ❤❡❧♣ ♦❢ ❛ ❝♦❧♦r ♠❛♣✳ ❚❤❡ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ♠❡t❤♦❞ ♣r❡s❡♥t❡❞ ✐♥ t❤❡

❢♦❧❧♦✇✐♥❣ s❡❝t✐♦♥ ✇❛s ✐♠♣❧❡♠❡♥t❡❞ ❛s ♠✉❧t✐♣❧❡ ♠♦❞✉❧❡s ❡①t❡♥❞✐♥❣ t❤❡ ❡①✐st✐♥❣

s♦❢t✇❛r❡✳

✹ ❖❜st❛❝❧❡ ❞❡t❡❝t✐♦♥

❆s s❡❡♥ ✐♥ s❡❝t✐♦♥ ✶✳✸✱ ❞❡t❡❝t✐♦♥ ♦❢ ♦❜st❛❝❧❡s ❝❛♥ ❜❡ r❡❞✉❝❡❞ t♦ ❞❡t❡❝t✐♦♥ ♦❢

✇❤✐t❡ ❝❛r❞❜♦❛r❞ ❜♦①❡s ✇✐t❤ ✇✐❞t❤ ❛♥❞ ❤❡✐❣❤t ♦❢ ✶✵✲✹✵ ♠♠ ❛♥❞ ❛ ❞❡♣t❤ ♦❢ ✶✵

❝♠ ♦r ♠♦r❡✳ ❚❤❡ ❝❛♠❡r❛✬s ❧✐♠✐t❡❞ ❤❡✐❣❤t ♦❢ ❝❛✳ ✶✻ ❝♠ ♠❡❛♥s t❤❛t ✐♥ ♥❡❛r❧②

❛❧❧ s✐t✉❛t✐♦♥s✱ ♦♥❧② t❤❡ ❢r♦♥t ♦❢ ❛♥ ♦❜st❛❝❧❡ ✐s ✈✐s✐❜❧❡ t♦ t❤❡ ❝❛♠❡r❛✳ ❇✉t ✇✐t❤

t❤❡ ❣✐✈❡♥ ❝♦♥str❛✐♥ts ♦❢ ✇❤❛t ❦✐♥❞ ♦❢ ♦❜st❛❝❧❡s ✇✐❧❧ ♦❝❝✉r ♦♥ t❤❡ tr❛❝❦ ❛♥❞ ✐♥

✇❤❛t ❝♦♥✜❣✉r❛t✐♦♥✱ ❦♥♦✇❧❡❞❣❡ ♦❢ t❤❡ ✇✐❞t❤ ♦❢ ❝❧♦s❡ ♦❜st❛❝❧❡s ❛♥❞ t❤❡ ❞✐st❛♥❝❡

❜❡t✇❡❡♥ t❤❡♠ ❛♥❞ t❤❡ ❝❛r ✐s s✉✣❝✐❡♥t t♦ ♥❛✈✐❣❛t❡ ❛r♦✉♥❞ t❤❡♠✳ ❚❤❡ ❣♦❛❧ ♦❢

t❤✐s s❡❝t✐♦♥ ✇✐❧❧ t❤❡r❡❢♦r❡ ❜❡ t♦ ❞❡s❝r✐❜❡ ❛♥ ❛❧❣♦r✐t❤♠ t❤❛t ❞❡t❡❝ts t❤❡ ❢r♦♥t

♦❢ t❤❡s❡ ♦❜st❛❝❧❡s ❛♥❞ r❡♣r❡s❡♥ts t❤❡♠ ❛s ❧✐♥❡ s❡❣♠❡♥ts ✐♥ ❛ ❜✐r❞s ❡②❡ ✈✐❡✇ ♦❢

t❤❡ s❝❡♥❡✳

❚♦ ❞❡t❡❝t t❤❡ ♦❜st❛❝❧❡ ❢r♦♥ts✱ ✐t ✐s ♥❡❝❡ss❛r② ✜rst t♦ ❛rt✐✜❝✐❛❧❧② ❝r❡❛t❡ ❛ ♠♦❞❡❧

♦❢ ✐❞❡❛❧ ❣r♦✉♥❞✳ ❙❡❝♦♥❞✱ t❤❡ ❞✐s♣❛r✐t② ♠❛♣ r❡❝❡✐✈❡❞ ❢r♦♠ t❤❡ st❡r❡♦ ❝❛♠❡r❛ ❤❛s

t♦ ❜❡ ❝♦♠♣❛r❡❞ ✇✐t❤ t❤✐s ❣r♦✉♥❞ ♠♦❞❡❧✳ ❚❤❡ ❣♦❛❧ ✐s t❤❡♥ t♦ ❞❡t❡❝t ❛r❡❛s ♦♥ t❤❡

❞✐s♣❛r✐t② ♠❛♣ t❤❛t r❡♣r❡s❡♥t ❛♣♣r♦①✐♠❛t❡❧② ♣❧❛✐♥ s✉r❢❛❝❡s ♦❢ ❡❧❡✈❛t❡❞ r❡❣✐♦♥s✳

❚❤❡ s♦❧✉t✐♦♥ ✉s❡❞ ❤❡r❡ ✐s ❛ r❡❝✉rs✐✈❡ ❛❧❣♦r✐t❤♠ t❤❛t ✐♥s♣❡❝ts ✐♥t❡r❡st✐♥❣ r❡❣✐♦♥s

✇✐t❤ ✐♥❝r❡❛s✐♥❣ ❛❝❝✉r❛❝②✳ ■t ♠❛❦❡s ✉s❡ ♦❢ ✐♥t❡❣r❛❧ ✐♠❛❣❡s ❛♥❞ ✐♠❛❣❡ ♣②r❛♠✐❞s

❛s ❞❡s❝r✐❜❡❞ ✐♥ s❡❝t✐♦♥ ✷✳✸ t♦ ❞♦ t❤✐s ❡✣❝✐❡♥t❧②✳ ❇♦✉♥❞✐♥❣ ❜♦①❡s ❝♦♥t❛✐♥✐♥❣

✐♠❛❣❡ ❛r❡❛s ♦❢ ♣♦t❡♥t✐❛❧ ♦❜st❛❝❧❡ s✉r❢❛❝❡ ❛r❡ t❤❡♥ r❡t✉r♥❡❞ ❜② t❤❡ ❛❧❣♦r✐t❤♠✳

❋✐♥❛❧❧②✱ t❤❡s❡ ❜♦✉♥❞✐♥❣ ❜♦①❡s ❛r❡ ♣r♦❥❡❝t❡❞ ❢r♦♠ t❤❡ ✐♠❛❣❡ ❝♦♦r❞✐♥❛t❡ ❢r❛♠❡

♦♥t♦ t❤❡ ❣r♦✉♥❞✳

✶✽

Page 24: Obstacle detection for an autonomous model car …...a stereo vision based real-time obstacle detection system for an autonomous model car on the scale of 1:10 built for the annual

✹ ❖❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ❏❛♥♥✐s ■❤r✐❣

✹✳✶ ❈r❡❛t✐♦♥ ♦❢ t❤❡ ❣r♦✉♥❞ ♠♦❞❡❧

❚❤❡ ❈❛r♦❧♦✲❈✉♣ ❣✉❛r❛♥t❡❡s ❛ ❜❧❛❝❦✱ ❧❡✈❡❧ ❣r♦✉♥❞ ❛♥❞ ✇❤✐t❡ ❧❛♥❡ ♠❛r❦✐♥❣s✳

❈♦♠❜✐♥❡❞ ✇✐t❤ t❤❡ ❧♦✇ ❤❡✐❣❤t ♦❢ t❤❡ st❡r❡♦ ❝❛♠❡r❛✱ t❤✐s ❧❡❛❞s t♦ ✐♥✈❛❧✐❞ ❞✐s✲

♣❛r✐t② ✈❛❧✉❡s ❛t ♥❡❛r❧② ❡✈❡r② ❞✐s♣❛r✐t② ♠❛♣ r❡❣✐♦♥ t❤❛t ❞❡♣✐❝ts t❤❡ ❣r♦✉♥❞✳

▲❛♥❡ ♠❛r❦✐♥❣s ❛♥❞ ♦❜❥❡❝ts ♣❧❛❝❡❞ ♦♥ t❤❡ tr❛❝❦ ♠♦st❧② r❡s✉❧t ✐♥ ✈❛❧✐❞ ❞✐s♣❛r✐✲

t✐❡s ❛s ♠♦r❡ ❢❡❛t✉r❡s ❝❛♥ ❜❡ ❢♦✉♥❞ ✐♥ t❤❡s❡ ✐♠❛❣❡ r❡❣✐♦♥s✳ ❚❤❡ s❡❝♦♥❞ ✐♠❛❣❡ ♦❢

✜❣✉r❡ ✶✵ s❤♦✇s ❛ ❝♦♠♠♦♥ s✐t✉❛t✐♦♥✳ ❚❤✐s ♠❛❦❡s ❡①tr❛❝t✐♥❣ t❤❡ ❣r♦✉♥❞ ♣❧❛♥❡

❢r♦♠ t❤❡ r❡❝❡✐✈❡❞ ❞✐s♣❛r✐t② ♠❛♣s ❞✐✣❝✉❧t✳ ❚❤❡ ❣♦❛❧ ♦❢ t❤✐s st❡♣ ✇✐❧❧ t❤❡r❡❢♦r❡

❜❡ t♦ ♣r♦❞✉❝❡ ❛♥ ❛rt✐✜❝✐❛❧ ✐♠❛❣❡ ♦❢ ✐❞❡❛❧ ❣r♦✉♥❞✳ ❆❝t✉❛❧ ❞✐s♣❛r✐t② ♠❛♣s ❝❛♥

t❤❡♥ ❜❡ ❝♦♠♣❛r❡❞ ❛❣❛✐♥st ✐t t♦ ❡①tr❛❝t ❡❧❡✈❛t✐♦♥s✳

❋✐❣✉r❡ ✶✵✿ ■♠❛❣❡ ♦❢ ❛ s❝❡♥❡ ❛♥❞ t❤❡ ❝♦rr❡s♣♦♥❞✐♥❣ ❞✐s♣❛r✐t② ♠❛♣✳ ❚❤❡ t❤✐r❞ ♣✐❝t✉r❡

s❤♦✇s t❤❡ ❞✐s♣❛r✐t② ♠❛♣ ✜❧❧❡❞ ✇✐t❤ ✈❛❧✉❡s ❢r♦♠ t❤❡ ❣r♦✉♥❞ ♠♦❞❡❧✳

❙❡❝t✐♦♥ ✷✳✷✳✸ s❤♦✇s t❤❛t t❤❡ r❡❧❛t✐♦♥ ❜❡t✇❡❡♥ t❤❡ ②✲❝♦♦r❞✐♥❛t❡s ♦❢ ♣✐①❡❧s ❛♥❞

t❤❡✐r ❞✐s♣❛r✐t② ✈❛❧✉❡s ✐s ❧✐♥❡❛r ❢♦r ❛ st❡r❡♦ ❝❛♠❡r❛ ✜❧♠✐♥❣ t❤❡ ❣r♦✉♥❞✱ ✐❢ t❤❡

❜❛s❡ ❧✐♥❡ ♦❢ t❤❡ ❝❛♠❡r❛ ✐s ♣❛r❛❧❧❡❧ t♦ t❤❡ ❣r♦✉♥❞ ♣❧❛♥❡✳ ❚❤❡r❡❢♦r❡✱ t✇♦ ♣✐①❡❧s

❢r♦♠ t❤❡ ❞✐s♣❛r✐t② ♠❛♣ ✇✐t❤ ✈❛❧✐❞ ✈❛❧✉❡s ❝❛♥ ❜❡ s❡❧❡❝t❡❞ ♠❛♥✉❛❧❧② ❛♥❞ ✉s❡❞

t♦ ❝r❡❛t❡ ❛ ❧✐♥❡ ✇❤✐❝❤ r❡♣r❡s❡♥ts t❤❡ ✇❤♦❧❡ ❣r♦✉♥❞ ♣❧❛♥❡✳ ❙✐♥❝❡ t❤❡ ❣♦❛❧ ✐s t♦

❝♦♠♣❛r❡ r❡❣✐♦♥s ♦❢ t❤❡ ❞✐s♣❛r✐t② ♠❛♣ ✇✐t❤ t❤❡ ❣r♦✉♥❞✱ ❛ ♥❡✇ ❣r♦✉♥❞ ❞✐s♣❛r✐t②

♠❛♣ ✐s ❝r❡❛t❡❞ ❛♥❞ ✜❧❧❡❞ ✇✐t❤ t❤❡ ❛♣♣r♦♣r✐❛t❡ ✈❛❧✉❡s ❞❡❞✉❝❡❞ ❢r♦♠ t❤❡ ❧✐♥❡❛r

♠♦❞❡❧✳

❇❡❝❛✉s❡ t❤❡ st❡r❡♦ ❝❛♠❡r❛ ✐s ❛❧✐❣♥❡❞ ❤♦r✐③♦♥t❛❧❧② ✇✐t❤ t❤❡ ❣r♦✉♥❞✱ t❤❡ ✐♠❛❣❡s

t❛❦❡♥ ✇✐❧❧ ❛❧✇❛②s ❝♦♥t❛✐♥ t❤❡ ❤♦r✐③♦♥ ❛t r♦✉❣❤❧② ❤❛❧❢ ♦❢ t❤❡✐r ❤❡✐❣❤t✳ ❚❤❡ ❧✐♥❡❛r

❣r♦✉♥❞ ♠♦❞❡❧ ✇✐❧❧ r❡t✉r♥ ♥❡❣❛t✐✈❡ ❞✐s♣❛r✐t✐❡s ❢♦r t❤❡ ❞✐s♣❛r✐t② ♠❛♣ r❡❣✐♦♥

❛❜♦✈❡ t❤❡ ❤♦r✐③♦♥✳ ❙✐♥❝❡ t❤✐s ✐s ♥♦t ✈❛❧✐❞✱ t❤❡s❡ r❡❣✐♦♥s ✇✐❧❧ ❜❡ ✜❧❧❡❞ ✇✐t❤ ✵s

✐♥st❡❛❞✳

❆ ❞✐st❛♥❝❡ ♠❛♣ ✐s ❝r❡❛t❡❞ ❢r♦♠ t❤❡ r❡s✉❧t✐♥❣ ❞✐s♣❛r✐t② ♠❛♣✳ ■t ❤❛s t❤❡ s❛♠❡

✇✐❞t❤ ❛♥❞ ❤❡✐❣❤t ❛s t❤❡ ❞✐s♣❛r✐t② ♠❛♣ ❜✉t ❝♦♥t❛✐♥s ❞✐st❛♥❝❡s ✐♥ ♠❡t❡rs ♦❜✲

t❛✐♥❡❞ ❜② ❛♣♣❧②✐♥❣ ❡q✉❛t✐♦♥ ✭✺✮ t♦ t❤❡ ❞✐s♣❛r✐t② ✈❛❧✉❡s✳ ❆❢t❡r✇❛r❞s ❛♥ ✐♥t❡❣r❛❧

✐♠❛❣❡ ♦❢ t❤❡ ❞✐st❛♥❝❡ ♠❛♣ ✐s ❝❛❧❝✉❧❛t❡❞ ❛♥❞ ♥❛♠❡❞ t❤❡ ❣r♦✉♥❞ ♠♦❞❡❧ G✳ ❚❤❡

✶✾

Page 25: Obstacle detection for an autonomous model car …...a stereo vision based real-time obstacle detection system for an autonomous model car on the scale of 1:10 built for the annual

✹ ❖❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ❏❛♥♥✐s ■❤r✐❣

✇❤♦❧❡ ♣r♦❝❡❞✉r❡ ♦❢ ❝r❡❛t✐♥❣ t❤❡ ❣r♦✉♥❞ ♠♦❞❡❧ ✐s ✐♥❞❡♣❡♥❞❡♥t ♦❢ ❢✉rt❤❡r ❝❛♠❡r❛

✐♥♣✉t ❛♥❞ t❤❡r❡❢♦r❡ ♥❡❡❞s t♦ ❜❡ ❞♦♥❡ ♦♥❧② ♦♥❝❡ ❛t ✐♥✐t✐❛❧✐③❛t✐♦♥✳

❚❤❡ ♠❡❛♥ ❞✐st❛♥❝❡ t♦ t❤❡ ❣r♦✉♥❞ ❢♦r ❛♥ ✐♠❛❣❡ ♣❛t❝❤ ❛s ❞❡s❝r✐❜❡❞ ✐♥ s❡❝t✐♦♥ ✷✳✹

✐s ❞❡♥♦t❡❞ ✇✐t❤ G(patch)✱ ❛ s❤♦rt❤❛♥❞ ❢♦r ❛♣♣❧②✐♥❣ ❡q✉❛t✐♦♥ ✭✾✮ t♦ G ❛♥❞ t❤❡

t♦♣ ❧❡❢t ❛♥❞ ❜♦tt♦♠ r✐❣❤t ♣✐①❡❧ ♦❢ patch✳

✹✳✷ ❉❡t❡❝t✐♥❣ ♦❜st❛❝❧❡ r❡❣✐♦♥s

❚❤✐s ♣❛rt ♦❢ t❤❡ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ s②st❡♠ ❝♦♥s✐sts ♦❢ ❛♥ ❛❧❣♦r✐t❤♠ t❤❛t ❞❡t❡❝ts

r❡❣✐♦♥s ♣♦t❡♥t✐❛❧❧② ❝♦♥t❛✐♥✐♥❣ ♦❜st❛❝❧❡s ♦♥ ❡❛❝❤ ❞✐s♣❛r✐t② ♠❛♣ r❡❝❡✐✈❡❞✳ ❚❤❡

❢♦❧❧♦✇✐♥❣ s✉❜s❡❝t✐♦♥ ✇✐❧❧ ✜rst ❣✐✈❡ ❛♥ ♦✈❡r✈✐❡✇ ♦✈❡r t❤❡ ❣❡♥❡r❛❧ str✉❝t✉r❡ ♦❢ t❤❡

❛❧❣♦r✐t❤♠✳ ❚❤❡ r❡st ♦❢ t❤❡ s❡❝t✐♦♥ t❤❡♥ ❞❡s❝r✐❜❡s t❤❡ s❡♣❛r❛t❡ st❡♣s ✐♥ ❞❡t❛✐❧✳

❚❤❡ ❛❧❣♦r✐t❤♠ ✉s❡s t❤r❡❡ ❞✐✛❡r❡♥t ✐♥t❡❣r❛❧ ✐♠❛❣❡s✳ ❚❤❡② ❛r❡ ♦❜t❛✐♥❡❞ ❢r♦♠

❛ ❞✐st❛♥❝❡ ♠❛♣ Idist ✺ t❤❛t ✐s ❝r❡❛t❡❞ ❢r♦♠ t❤❡ ❞✐s♣❛r✐t② ♠❛♣ I✳ ❚❤❡ ✜rst

✐♥t❡❣r❛❧ ✐♠❛❣❡ ✐s ❝❛❧❧❡❞ ❞❡♥s❡ ✐♥t❡❣r❛❧ ❞✐st❛♥❝❡ ✐♠❛❣❡ Sdense ❛♥❞ ❝r❡❛t❡❞ ❢r♦♠

Idist ✐♥ ❝♦♠❜✐♥❛t✐♦♥ ✇✐t❤ t❤❡ ❣r♦✉♥❞ ♠♦❞❡❧✳ ■t ✐s ✉s❡❞ t♦ ❞❡t❡❝t ❡❧❡✈❛t✐♦♥s ✐♥

s❡❝t✐♦♥ ✹✳✷✳✶✳ ❆ s❡❝♦♥❞ ❛♥❞ t❤✐r❞ ✐♥t❡❣r❛❧ ✐♠❛❣❡ ❛r❡ ✉s❡❞ ✐♥ ❝♦♠❜✐♥❛t✐♦♥ t♦

♦❜t❛✐♥ ✉♥❛❧t❡r❡❞ ♠❡❛♥ ❞✐st❛♥❝❡s ♦✈❡r r❡❣✐♦♥s ♦❢ Idist✳ ❚❤❡s❡ ❛r❡ ❝❛❧❧❡❞ Ssparse

❛♥❞ SvalidP ixels✳ ❚❤❡② ❛r❡ ✉s❡❞ ✐♥ s❡❝t✐♦♥ ✹✳✷✳✷✳ ❋♦r ❡❛❝❤ ♦❢ t❤❡s❡ ✐♥t❡❣r❛❧

✐♠❛❣❡s✱ ❛♥ ✐♠❛❣❡ ♣②r❛♠✐❞ ❛s ❞❡s❝r✐❜❡❞ ✐♥ s❡❝t✐♦♥ ✷✳✹ ✐s ❝♦♥str✉❝t❡❞✳

❆❧❣♦r✐t❤♠ ✶ ♦✉t❧✐♥❡s t❤❡ st❡♣s ♦❢ t❤❡ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ❛❧❣♦r✐t❤♠ ✐♥ ♣s❡✉❞♦

❝♦❞❡✳ ❙✐♥❝❡ ✐t s❤♦✉❧❞ st❛rt ✇✐t❤ ❛♥❛❧②③✐♥❣ t❤❡ ❧♦✇❡st ❧❡✈❡❧ ♦❢ t❤❡ ✐♠❛❣❡

♣②r❛♠✐❞s ✇✐t❤ ♣✐①❡❧s t❤❛t r❡❧❛t❡ t♦ t❤❡ ✇❤♦❧❡ ❞✐st❛♥❝❡ ♠❛♣✱ t❤❡ ✐♥♣✉t ✐s

cdense = Sdense0 (0, 0)✳

❙✐♥❝❡ t❤❡ ❛❧❣♦r✐t❤♠ ✉s❡s ♠❡❛♥ ❞✐st❛♥❝❡s ♦✈❡r r❡❣✐♦♥s ♦❢ Idist ♦♥ ❞✐✛❡r❡♥t s❝❛❧❡s

r❡♣r❡s❡♥t❡❞ ❜② ♣✐①❡❧s ♦♥ ❞✐✛❡r❡♥t ❧❡✈❡❧s ♦❢ t❤❡ ✐♠❛❣❡ ♣②r❛♠✐❞s✱ t❤❡ t❤r❡s❤✲

♦❧❞s minElevation ❛♥❞ inspectThreshold ❞❡♣❡♥❞ ♦♥ t❤❡ ❝✉rr❡♥t ❧❡✈❡❧ l✳ ❚❤❡

❛❧❣♦r✐t❤♠ ✜rst ✐♥s♣❡❝ts ❛ ❢❡✇ ❜✐❣ r❡❣✐♦♥s ✈✐❛ ♣✐①❡❧s ♦❢ ❧♦✇❡r ❧❡✈❡❧s ♦♥ t❤❡ ✐♠✲

❛❣❡ ♣②r❛♠✐❞s ❛♥❞ ♦♥❧② ❣♦❡s ✐♥t♦ ❞❡t❛✐❧ ✐❢ ❡❧❡✈❛t✐♦♥s ❛r❡ ❞❡t❡❝t❡❞ t❤❛t ❝♦♥t❛✐♥

str✉❝t✉r❡ ✇❤✐❝❤ ❝❛♥ ♥♦t ❜❡ ❛♣♣r♦①✐♠❛t❡❞ s✉✣❝✐❡♥t❧② ♦♥ t❤❡ ❝✉rr❡♥t ❧❡✈❡❧✳ ❚❤❡

✐♠❛❣❡ ♣②r❛♠✐❞s ❛r❡ ❝♦♥str✉❝t❡❞ ❞✉r✐♥❣ r✉♥t✐♠❡ ❜✉t ♦♥❧② ❢♦r ❧❡✈❡❧s ❛♥❞ ♣✐①❡❧s

t❤❛t ❛r❡ ✐♥s♣❡❝t❡❞✳ ❚❤✐s ✐♥❝r❡❛s❡s t❤❡ ❛❧❣♦r✐t❤♠✬s ♣❡r❢♦r♠❛❝❡✳ ❆s t❤❡ ✐♠♣❛❝t

✺Idist ❛❝t✉❛❧❧② ♥❡✈❡r ❡①✐sts ✐♥❞❡♣❡♥❞❡♥t❧②✳ ❉✐st❛♥❝❡ ✈❛❧✉❡s ❛r❡ ❝❛❧❝✉❧❛t❡❞ t♦ ❝r❡❛t❡ t❤❡t❤r❡❡ ✐♥t❡❣r❛❧ ✐♠❛❣❡s ❜✉t ♥♦t st♦r❡❞ ✐♥ ❛ s❡♣❛r❛t❡ ✐♠❛❣❡✳ P✐①❡❧s ♦♥ t❤❡ ✐♠❛❣❡ ♣②r❛♠✐❞s ❝♦♥✲t❛✐♥ t❤❡ ♠❡❛♥ ✈❛❧✉❡s ♦❢ ✐♠❛❣❡ ♣❛t❝❤❡s ♦❢ Idist✳ ❇✉t ❛s ❜♦t❤ ✐♠❛❣❡s I ❛♥❞ Idist ❝♦♥t❛✐♥ ♥❡❛r❧②t❤❡ s❛♠❡ ✐♥❢♦r♠❛t✐♦♥ ❛♥❞ ❝❛♥ t❤❡r❡❢♦r❡ ❜❡ ✉s❡❞ ✐♥t❡r❝❤❛♥❣❡❛❜❧② ✐❢ ♥♦t st❛t❡❞ ♦t❤❡r✇✐s❡✳

✷✵

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✹ ❖❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ❏❛♥♥✐s ■❤r✐❣

❢✉♥❝t✐♦♥ ❞❡t❡❝t✭cdense = Sdensel (x, y)✮

✐❢ ❧ ❁ st❛rt▲❡✈❡❧ t❤❡♥❢♦r ❝❤✐❧❞ ✐♥ ❝❤✐❧❞r❡♥✭cdense✮ ❞♦

❞❡t❡❝t✭child✮❀r❡t✉r♥❀

✐❢ elevation(cdense) >= minElevation(l) t❤❡♥✐❢ ❧ ❂❂ ♠❛①▲❡✈❡❧ t❤❡♥

s❡❧❡❝t cdense ❛♥❞ ♠❡r❣❡ ✐t ✇✐t❤ s❡❧❡❝t❡❞ ♥❡✐❣❤❜♦rs❀r❡t✉r♥❀

csparse = Ssparsel (x, y)❀

❝❛❧❝✉❧❛t❡ t❤❡ s✉♠ ♦❢ sq✉❛r❡ ❞✐st❛♥❝❡s ssqd ❜❡t✇❡❡♥ csparse ❛♥❞children(csparse)❀✐❢ ssq❞ ❁❂ ✐♥s♣❡❝t❚❤r❡s❤♦❧❞✭❧✮ t❤❡♥

❛❝❝❡♣t csparse ❛s ❛♥ ❛♣♣r♦①✐♠❛t✐♦♥ ❢♦r patch(csparse)✱ s❡❧❡❝t cdense

❛♥❞ ♠❡r❣❡ ✐t ✇✐t❤ s❡❧❡❝t❡❞ ♥❡✐❣❤❜♦rs❀r❡t✉r♥❀

❡❧s❡❢♦r ❝❤✐❧❞ ✐♥ ❝❤✐❧❞r❡♥✭cdense✮ ❞♦

❞❡t❡❝t✭❝❤✐❧❞✮❀r❡t✉r♥❀

❡❧s❡r❡❥❡❝t cdense ❛s ✐t ✐s ♥♦ ♦❜st❛❝❧❡ r❡❣✐♦♥❀r❡t✉r♥❀

❆❧❣♦r✐t❤♠ ✶✿ ❉❡t❡❝t✐♥❣ ♦❜st❛❝❧❡ r❡❣✐♦♥s✳

♦❢ s♠❛❧❧ r❡❣✐♦♥s ♦❢ Idist ♦♥ t❤❡ ✈❛❧✉❡ ♦❢ ♣✐①❡❧s ♦♥ ❧♦✇ ♣②r❛♠✐❞ ❧❡✈❡❧s ✐s s♠❛❧❧✱

t❤❡ ✜rst ❧❡✈❡❧s ❜❡❧♦✇ startLevel ❝❛♥ ❜❡ ✐❣♥♦r❡❞ ❛♥❞ t❤❡ ❛❧❣♦r✐t❤♠ ❞✐r❡❝t❧② ❛s✲

❝❡♥❞s ♦♥t♦ t❤❡ ♥❡①t ❧❡✈❡❧✳ ▼♦r❡♦✈❡r✱ ❛ ❜✐❣ ✐♠❛❣❡ ❛r❡❛ ❛❜♦✈❡ t❤❡ ❤♦r✐③♦♥ ❝❛♥

❛❧s♦ ❜❡ ✐❣♥♦r❡❞ ❛s ❛❧❧ ♦❜st❛❝❧❡s ♠✉st t♦✉❝❤ t❤❡ ❣r♦✉♥❞ ✭s❡❡ ✜❣✉r❡ ✶✶✮✳❙✐♥❝❡

t❤❡ ❝❛♠❡r❛ ♣♦s✐t✐♦♥ ✐s ✜①❡❞✱ t❤✐s ❛r❡❛ ❝❛♥ ❜❡ ♣❛ss❡❞ t♦ t❤❡ ❛❧❣♦r✐t❤♠ ✇✐t❤

❛ ♣❛r❛♠❡t❡r ❝❛❧❧❡❞ horizonY ✻✳ Idist ✐s ♣❧❛❝❡❞ ♦♥ ❛ ❝❛♥✈❛s ✇✐t❤ ❛ ✇✐❞t❤ ❛♥❞

❤❡✐❣❤t t❤❛t ❡q✉❛❧ ❛ ♣♦✇❡r ♦❢ t✇♦ t❤❛t ✐s ❜✐❣❣❡r t❤❛♥ Idists ✇✐❞t❤ ❛♥❞ ❤❡✐❣❤t✳

❚❤❡ ✐♠❛❣❡ ♣②r❛♠✐❞s ❛r❡ t❤❡♥ ❝r❡❛t❡❞ ❢r♦♠ t❤❡ ❝❛♥✈❛s ❝♦♥t❛✐♥✐♥❣ t❤❡ ✐♠❛❣❡✳

❚❤❡ ❝❛♥✈❛s ❤❡❧♣s t♦ ❛✈♦✐❞ ✐♥❞❡①✐♥❣ ♣r♦❜❧❡♠s ❞✉r✐♥❣ t❤✐s st❡♣✳ P✐①❡❧s t❤❛t r❡♣✲

r❡s❡♥t ♣❛t❝❤❡s ♦✉ts✐❞❡ t❤❡ ❛❝t✉❛❧ ❞✐st❛♥❝❡ ♠❛♣ ❝❛♥ t❤❡♥ ❜❡ ✐❣♥♦r❡❞ ❞✉r✐♥❣ t❤❡

❞❡t❡❝t✐♦♥ st❡♣ ♦❢ t❤❡ ❛❧❣♦r✐t❤♠✳ P✐①❡❧s r❡❧❛t❡❞ t♦ ♣❛t❝❤❡s t❤❛t ♣❛rt❧② ♦✈❡r❧❛♣

t❤❡ ♠❛♣ ❤❛✈❡ t♦ ❜❡ ✐♥s♣❡❝t❡❞ ♠♦r❡ ❝❧♦s❡❧②✱ ❛❧s♦ s❡❡♥ ❛t t❤❡ ♦✉t❡r r❡❣✐♦♥s ♦❢

✻horizonY ❤❛s t♦ ❜❡ s❡t s❧✐❣❤t❧② ❛❜♦✈❡ t❤❡ ❤♦r✐③♦♥ s♦ t❤❛t ❡❧❡✈❛t❡❞ r❡❣✐♦♥s ❝❧♦s❡ t♦ ✐t❝❛♥ ❜❡ ❞❡t❡❝t❡❞✳

✷✶

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✹ ❖❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ❏❛♥♥✐s ■❤r✐❣

t❤❡ ❧❡❢t ✐♠❛❣❡ ♦❢ ✜❣✉r❡ ✶✶✳

❋✐❣✉r❡ ✶✶✿ ■♠❛❣❡ ♣❛t❝❤❡s r❡❧❛t❡❞ t♦ ❛♥ ✐♠❛❣❡ ♣②r❛♠✐❞✳ ❨❡❧❧♦✇ ♣❛t❝❤❡s ❛r❡ s❡❧❡❝t❡❞

❛s ❛♥ ♦❜st❛❝❧❡ ✇❛s ❞❡t❡❝t❡❞✳

❚❤❡ ❢♦❧❧♦✇✐♥❣ s❡❝t✐♦♥s ✇✐❧❧ ❞❡s❝r✐❜❡ ✇❤❛t ✐s r❡❣❛r❞❡❞ ❛s ❛ ❡❧❡✈❛t✐♦♥✱ ❤♦✇ ♦❜✲

st❛❝❧❡ s✉r❢❛❝❡s ❛r❡ ❛♣♣r♦①✐♠❛t❡❞ ❛♥❞ ❛♥❞ ✜♥❛❧❧② ❤♦✇ s❡❧❡❝t❡❞ ✐♠❛❣❡ ♣❛t❝❤❡s

❛r❡ ♠❡r❣❡❞ t♦ ❝r❡❛t❡ ❜♦✉♥❞✐♥❣ ❜♦①❡s ❢♦r ✇❤♦❧❡ ♦❜st❛❝❧❡ r❡❣✐♦♥s✳

✹✳✷✳✶ ❉❡t❡❝t✐♥❣ ❡❧❡✈❛t❡❞ r❡❣✐♦♥s

❉❡t❡❝t✐♥❣ r❡❣✐♦♥s ♦♥ t❤❡ ❞✐s♣❛r✐t② ♠❛♣ I t❤❛t ❞✐s♣❧❛② ❡❧❡✈❛t✐♦♥s ❝❛♥ ❜❡ ❞♦♥❡

❜② ❝♦♠♣❛r✐♥❣ ✐t t♦ t❤❡ ❣r♦✉♥❞ ♠♦❞❡❧ G✳ ❆♥ ✐♥t❡❣r❛❧ ✐♠❛❣❡ ✐s ❝r❡❛t❡❞ t♦

❜❡ ❛❜❧❡ t♦ ❝❛❧❝✉❧❛t❡ t❤❡ ❞✐✛❡r❡♥❝❡ ❜❡t✇❡❡♥ ❣r♦✉♥❞ ♠♦❞❡❧ ❛♥❞ ❞✐s♣❛r✐t② ♠❛♣

♦✈❡r ❛r❜✐tr❛r② r❡❣✐♦♥s ✐♥ ❝♦♥st❛♥t t✐♠❡✳ ❇✉t t❤❡ ♥♦♥✲❧✐♥❡❛r r❡❧❛t✐♦♥ ❜❡t✇❡❡♥

❞✐s♣❛r✐t② ❛♥❞ ❞✐st❛♥❝❡ ❞❡s❝r✐❜❡❞ ✐♥ s❡❝t✐♦♥ ✷✳✷✳✸ ♠❛❦❡s ✐t ♥❡❝❡ss❛r② t♦ ✜rst

❝♦♥✈❡rt t❤❡ ❞✐s♣❛r✐t② ♠❛♣ ✐♥t♦ t❤❡ ❞✐st❛♥❝❡ ♠❛♣ Idist✳ ❚❤✐s ✐s ❞♦♥❡ t❤❡ s❛♠❡

✇❛② ❛s ✐♥ s❡❝t✐♦♥ ✹✳✶✳ ❚❤❡♥ t❤❡ ✐♥t❡❣r❛❧ ✐♠❛❣❡ Sdense ✐s ❝❛❧❝✉❧❛t❡❞ ❢r♦♠ Idist✳ ❆t

r❡❣✐♦♥s ✇❤❡r❡ Idist ❝♦♥t❛✐♥s ✐♥✈❛❧✐❞ ✈❛❧✉❡s✱ ❞✐s♣❛r✐t✐❡s ❢r♦♠ G ❛r❡ ✉s❡❞ ✐♥st❡❛❞

t♦ ❝❛❧❝✉❧❛t❡ Sdense✳ ❖t❤❡r✇✐s❡✱ s♣❛rs❡ r❡❣✐♦♥s ✇♦✉❧❞ ❜❡ t♦♦ s✉s❝❡♣t✐❜❧❡ t♦ ♥♦✐s❡✳

Sdense ❢♦r♠s t❤❡ ❜❛s✐s ❢♦r ❛♥ ✐♠❛❣❡ ♣②r❛♠✐❞ ❝♦♥str✉❝t❡❞ ❞✉r✐♥❣ r✉♥t✐♠❡✳

◆♦✇ ❛ ♣✐①❡❧ cdense = Sdensel (x, y) ✐s ✐♥s♣❡❝t❡❞✳ ■t ✐s ♣♦ss✐❜❧❡ t♦ ❝❛❧❝✉❧❛t❡ t❤❡

❡❧❡✈❛t✐♦♥ ❛❜♦✈❡ t❤❡ ❣r♦✉♥❞ ❢♦r t❤❡ r❡❣✐♦♥ patch(cdense) ♦♥ Idist ❛s ❢♦❧❧♦✇s✿

elevation(cdense) = max(0, cdense −G(patch(cdense)) ✭✶✵✮

■♠❛❣❡ r❡❣✐♦♥s t❤❛t ✐♥❞✐❝❛t❡ ❛r❡❛s t❤❛t ❧✐❡ ❜❡❧♦✇ t❤❡ ❣r♦✉♥❞ ♣❧❛♥❡ ❝❛♥ ❜❡ ✐❣✲

♥♦r❡❞ ❛s t❤❡ ✢❛t ❣r♦✉♥❞ ✐s ❣✉❛r❛♥t❡❡❞✳

■t ✐s t❤❡♥ ♣♦ss✐❜❧❡ t♦ t❡st t❤❡ ❝♦♠♣✉t❡❞ ❡❧❡✈❛t✐♦♥ ❛❣❛✐♥st t❤❡ t❤r❡s❤♦❧❞minElevation(l)

✷✷

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✹ ❖❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ❏❛♥♥✐s ■❤r✐❣

✇❤✐❝❤ ❞❡♣❡♥❞s ♦♥ t❤❡ ❝✉rr❡♥t ❧❡✈❡❧ ♦❢ t❤❡ ✐♠❛❣❡ ♣②r❛♠✐❞✳ ❆ s❡♥s✐❜❧❡ ✈❛❧✉❡ ✐s

minElevation(l) =minObstacleHeight

4(maxLevels−l)✭✶✶✮

✇❤❡r❡ minObstacleHeight ✐s t❤❡ ♠✐♥✐♠❛❧ ❤❡✐❣❤t ❢♦r ❛♥ ♦❜❥❡❝t t♦ ❜❡ ❝♦✉♥t❡❞

❛s ❛♥ ♦❜st❛❝❧❡✳ ❇② ❝❤♦♦s✐♥❣ t❤❡ t❤r❡s❤♦❧❞ ✐♥ t❤✐s ♠❛♥♥❡r✱ ❛♥② ♦❜❥❡❝t t❤❛t ❤❛s

❛t ❧❡❛st minObstacleHeight ❛♥❞ ✜❧❧s ❛t ❧❡❛st ❛♥ ✐♠❛❣❡ r❡❣✐♦♥ ♦❢ t❤❡ s✐③❡ ♦❢ ❛

♣❛t❝❤ ♦♥ maxLevels ✐s ❝♦♥s✐❞❡r❡❞ ❛♥ ♦❜st❛❝❧❡✳

✹✳✷✳✷ ❆♣♣r♦①✐♠❛t✐♥❣ t❤❡ s✉r❢❛❝❡

❋♦r t❤✐s st❡♣ t❤❡ ✐♥t❡❣r❛❧ ✐♠❛❣❡s Ssparse ❛♥❞ SvalidP ixels ❛♥❞ t❤❡✐r ❛ss♦❝✐❛t❡❞

✐♠❛❣❡ ♣②r❛♠✐❞s ❛r❡ ❝r❡❛t❡❞ ❢r♦♠ Idist✳ Ssparse ♠❛❦❡s ✐t ♣♦ss✐❜❧❡ t♦ ♦❜t❛✐♥

✉♥❛❧t❡r❡❞ ♠❡❛♥ ❞✐st❛♥❝❡s ♦✈❡r ❛r❜✐tr❛r② r❡❝t❛♥❣✉❧❛r ✐♠❛❣❡ r❡❣✐♦♥s ♦♥ Idist✳

SvalidP ixels ♣r♦✈✐❞❡s t❤❡ ♥✉♠❜❡r ♦❢ ✈❛❧✐❞ ♣✐①❡❧s ❢♦r t❤❡s❡ ✐♠❛❣❡ r❡❣✐♦♥s ✐♥ ❝❛s❡

t❤❡r❡ ❛r❡ s♣❛rs❡ r❡❣✐♦♥s ♦♥ t❤❡ ❞✐st❛♥❝❡ ♠❛♣✳ ❚❤❡ ♥❡❝❡ss✐t② ❢♦r ❛♥❞ ❝r❡❛t✐♦♥

♦❢ SvalidP ixels ✐s ❞❡s❝r✐❜❡❞ ✐♥ s❡❝t✐♦♥ ✷✳✸✳

❚❤❡ ❧❛st st❡♣ ♦❢ t❤❡ ❛❧❣♦r✐t❤♠ ❞❡t❡❝ts ❛♥ ✐♠❛❣❡ r❡❣✐♦♥ patch(cdense) ❢♦r cdense =

Sdensel (x, y) t❤❛t ❝♦♥t❛✐♥s ♦♥❡ ♦r ♠♦r❡ ❡❧❡✈❛t✐♦♥s✳ ❚❤❡ q✉❡st✐♦♥ ♥♦✇ ✐s ✇❤❡t❤❡r

t❤❡r❡ ✐s ♦♥❡ ❡❧❡✈❛t✐♦♥ t❤❛t ✜❧❧s t❤❡ ✇❤♦❧❡ r❡❣✐♦♥ ♦r t❤❡ r❡❣✐♦♥ ❤❛s t♦ ❜❡ ✐♥s♣❡❝t❡❞

♠♦r❡ ❝❧♦s❡❧②✳ csparse ✐s ✉s❡❞ t♦ ❞❡s❝r✐❜❡ t❤❡ ♠❡❛♥ ❞✐st❛♥❝❡ ❢♦r patch(csparse)✳ ■❢

t❤❡ r❡❣✐♦♥ ❤❛s t♦ ❜❡ ❢✉rt❤❡r ✐♥s♣❡❝t❡❞✱ t❤✐s ✇✐❧❧ ❜❡ ❞♦♥❡ ❜② t❛❦✐♥❣ ❛ ❧♦♦❦ ❛t

children(csparse)✳

❚♦ ❞♦ ❛❧❧ t❤✐s✱ ✐t ✐s ✜rst ❛ss✉♠❡❞ t❤❛t t❤❡ ♣❧❛♥❡ ♣❛r❛❧❧❡❧ t♦ t❤❡ ✐♠❛❣❡ ♣❧❛♥❡ ❛♥❞

❞❡✜♥❡❞ ❜② csparse s✉✣❝✐❡♥t❧② ❛♣♣r♦①✐♠❛t❡s t❤❡ s✉r❢❛❝❡ ♦❢ patch(csparse) ✼✳ ❚❤❡♥

t❤❡ s✉♠ ♦❢ sq✉❛r❡ ❞✐st❛♥❝❡s ssqd ❜❡t✇❡❡♥ csparse ❛♥❞ ✐ts ❝❤✐❧❞r❡♥ ✐s ❝❛❧❝✉❧❛t❡❞✿

ssqd(csparse) =∑

r ∈ children(csparse)

(csparse − r)2 ✭✶✷✮

■t ✐s ♥❡❝❡ss❛r② t♦ ✐♥s♣❡❝t ❡❛❝❤ ❝❤✐❧❞ ✐♥ ❞❡t❛✐❧ ✐❢ ssqd(csparse) >= inspectThreshold(l)✱

✇❤❡r❡ t❤❡ t❤r❡s❤♦❧❞ ❝❛♥ ❜❡ ❞❡✜♥❡❞ ❛s

inspectThreshold(l) =fixedInspectThreshold

4(maxLevels−l)✭✶✸✮

❛♥❛❧♦❣♦✉s t♦minElevation ✐♥ ❡q✉❛t✐♦♥ ✭✶✶✮✳ ■❢ t❤❡ ❛♣♣r♦①✐♠❛t✐♦♥ ♦❢ patch(csparse)

✼✷✳✷✳✸ ❞❡s❝r✐❜❡s t❤❛t t❤❡ ❛ ✜①❡❞ ❞✐s♣❛r✐t② ❞❡✜♥❡s ❛ ♣❧❛♥❡ ♣❛r❛❧❧❡❧ t♦ t❤❡ ✐♠❛❣❡ ♣❧❛♥❡s ♦❢t❤❡ st❡r❡♦ ❝❛♠❡r❛✳ ❚❤❡ s❛♠❡ ✐s tr✉❡ ❢♦r ❛ ✜①❡❞ ❞✐st❛♥❝❡ ✐♥ ♠❡t❡rs✳

✷✸

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✹ ❖❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ❏❛♥♥✐s ■❤r✐❣

✐s ❛❝❝❡♣t❡❞✱ t❤❡ ❞❡♥s✐t② ♦❢ t❤❡ ❝❤✐❧❞r❡♥✬s ♣❛t❝❤❡s ♦♥ t❤❡ ❞✐st❛♥❝❡ ♠❛♣ ❝♦✉❧❞ ❜❡

✐♥s♣❡❝t❡❞ r❡s♣❡❝t✐✈❡❧②✳ ❇✉t s✐♥❝❡ t❤❡ st❡♣ ✐♥ s❡❝t✐♦♥ ✹✳✷✳✶ ❝❛❧❝✉❧❛t❡s t❤❡ ❡❧❡✈❛✲

t✐♦♥ ♦❢ ♣❛t❝❤❡s ✇✐t❤ t❤❡ ❤❡❧♣ ♦❢ t❤❡ ❞❡♥s❡ ✐♥t❡❣r❛❧ ❞❡♥s✐t② ♠❛♣✱ ♦♥❧② r❡❣✐♦♥s

t❤❛t ❤❛✈❡ ❛ ❤✐❣❤❡r ♥✉♠❜❡r ♦❢ ♣✐①❡❧s ✇✐t❤ ✈❛❧✐❞ ❞✐st❛♥❝❡s ❛r❡ s❡❧❡❝t❡❞✳

❋✐❣✉r❡ ✶✷✿ ❙❡❧❡❝t❡❞ ✐♠❛❣❡ r❡❣✐♦♥s✳ ❇♦t❤ ✐♠❛❣❡s s❤♦✇ t❤❡ s❛♠❡ ♦❜❥❡❝t ♣❧❛❝❡❞ ✐♥

❞✐✛❡r❡♥t ❛♥❣❧❡s t♦ t❤❡ ❝❛♠❡r❛✳

❚❤❡ r❡❝✉rs✐♦♥ st♦♣s ♦♥ maxLevel ✇❤✐❝❤ ❝❛♥ ❜❡ ❝❤♦s❡♥ ❢r❡❡❧②✳ P✐①❡❧s ♦♥ t❤✐s

❤✐❣❤❡st ❧❡✈❡❧ ♦❢ t❤❡ ✐♠❛❣❡ ♣②r❛♠✐❞s ❛r❡ s❡❧❡❝t❡❞ ✇✐t❤♦✉t ✐♥s♣❡❝t✐♥❣ t❤❡ ❝❤✐❧❞r❡♥

♦❢ csparse✱ ♦♥❧② ♦♥ t❤❡ ❜❛s✐s ♦❢ ❡❧❡✈❛t✐♦♥ ❛❜♦✈❡ ❣r♦✉♥❞✳

❚❤❡ ❣❡♥❡r❛❧ r❡s✉❧t ♦❢ t❤✐s st❡♣ ✐s ❛ s❡❧❡❝t✐♦♥ ♦❢ ♣✐①❡❧s ♦♥ ❞✐✛❡r❡♥t ♣②r❛♠✐❞ ❧❡✈❡❧s✳

P✐①❡❧s ♦♥ ❤✐❣❤❡r ❧❡✈❡❧s ❛r❡ s❡❧❡❝t❡❞ t♦ ❞❡s❝r✐❜❡ s✉r❢❛❝❡s t❤❛t ❛r❡ r♦✉❣❤❧② ❡✈❡♥

❛♥❞ ♣❛r❛❧❧❡❧ t♦ t❤❡ ✐♠❛❣❡ ♣❧❛♥❡✳ ❉❡♣❡♥❞✐♥❣ ♦♥ t❤❡ s✐③❡✱ ❞✐st❛♥❝❡ ❛♥❞ ❛♥❣❧❡ ♦❢

❛♥ ♦❜❥❡❝t ✐♥ t❤❡ ✐♠❛❣❡✱ s❡❧❡❝t❡❞ r❡❣✐♦♥s ❜❡❝♦♠❡ ❢r❛❣♠❡♥t❡❞ ✐♥ ♠✉❧t✐♣❧❡ ♣❛t❝❤❡s

r❡♣r❡s❡♥t❡❞ ❜② ♣✐①❡❧s ♦♥ ❤✐❣❤❡r ❧❡✈❡❧s ♦❢ t❤❡ ✐♠❛❣❡ ♣②r❛♠✐❞ ✭s❡❡ ✜❣✉r❡ ✶✷✮✳

✹✳✷✳✸ ▼❡r❣✐♥❣ ❝❡❧❧s

❚❤✐s st❡♣ ♦❢ t❤❡ ❛❧❣♦r✐t❤♠ ✇✐❧❧ ♠❡r❣❡ ♥❡✐❣❤❜♦r✐♥❣ ♣❛t❝❤❡s r❡❧❛t❡❞ t♦ s❡❧❡❝t❡❞

♣✐①❡❧s ♦♥ t❤❡ ✐♠❛❣❡ ♣②r❛♠✐❞ ♦❢ Ssparse ✐♥t♦ ♦♥❡ ♦❜st❛❝❧❡ r❡❣✐♦♥ O✳ O ❝♦♥s✐sts ♦❢

t❤❡ s❡t ♦❢ t❤❡s❡ ♣✐①❡❧s ❛♥❞ t❤❡ r❡❧❛t❡❞ ♣❛t❝❤❡s t❤❛t ❛r❡ ❝♦♥t❛✐♥❡❞ ❜② ❛ ❜♦✉♥❞✐♥❣

❜♦① ❞❡s❝r✐❜❡❞ t❤r♦✉❣❤ ❛ t♦♣ ❧❡❢t ❛♥❞ ❜♦tt♦♠ r✐❣❤t ♣♦✐♥t✳ ❚❤❡ ♠❡❛♥ ✈❛❧✉❡ ♦✈❡r

❛❧❧ ♠❡❛♥ ❞✐st❛♥❝❡s✱ meanDist(O) ✐s✿

meanDist(O) =1

|O|

csparse ∈ O

value(csparse) ✭✶✹✮

❚❤✐s ✐s ✉s❡❞ ❛s ❛ ❝r✐t❡r✐❛ ❢♦r ♠❡r❣✐♥❣ s❡❧❡❝t❡❞ ♣❛t❝❤❡s✳ minDist(O) ✐s t❤❡

♠✐♥✐♠❛❧ ✈❛❧✉❡ ♦❢ ❛❧❧ ♣✐①❡❧s ✐♥ O✳ ■t ✐s ✉s❡❞ t♦❣❡t❤❡r ✇✐t❤ t❤❡ ✇✐❞t❤ ♦❢ t❤❡

✷✹

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✹ ❖❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ❏❛♥♥✐s ■❤r✐❣

❞❡t❡❝t❡❞ ♦❜st❛❝❧❡ ❢r♦♥t t♦ ♠♦❞❡❧ t❤❡ ❛❝t✉❛❧ ♦❜st❛❝❧❡ ❢r♦♥t ❛s t❤❡ ❡①❛❝t str✉❝t✉r❡

✇✐❧❧ ♥♦t ❜❡ ❦♥♦✇♥ ❛❢t❡r t❤❡ ♠❡r❣✐♥❣ ♣r♦❝❡ss✳

❋♦r ❡❛❝❤ s❡❧❡❝t❡❞ ♣✐①❡❧ csparse ✐t ✐s ♥♦✇ ♥❡❝❡ss❛r② t♦ ❝❤❡❝❦ ❢♦r s❡❧❡❝t❡❞ ♥❡✐❣❤✲

❜♦rs ❛♥❞ ♠❡r❣❡ csparse ✐♥t♦ t❤❡✐r r❡❧❛t❡❞ ♦❜st❛❝❧❡ r❡❣✐♦♥s ✐❢ ♣♦ss✐❜❧❡✳ P✐①❡❧s ❛r❡

✐♥s♣❡❝t❡❞ ❢r♦♠ t♦♣ t♦ ❜♦tt♦♠ ❛♥❞ ❧❡❢t t♦ r✐❣❤t ♦♥ ♦♥❡ ✐♠❛❣❡ ♦❢ t❤❡ ✐♠❛❣❡ ♣②r❛✲

♠✐❞ ❛♥❞ ❢r♦♠ ✐ts ❧♦✇❡st ❧❡✈❡❧ t♦ ✐ts ❤✐❣❤❡st ❧❡✈❡❧✳ ❚❤❛t ✐s ✇❤② t❤❡ ❝❛♥❞✐❞❛t❡s

❢♦r ♠❡r❣✐♥❣ ✇✐t❤ csparse ❛r❡ ❧♦❝❛t❡❞ ❛❜♦✈❡ ❛♥❞ ❧❡❢t ♦❢ ✐t ✭✐♥ ✐♠❛❣❡ ❝♦♦r❞✐♥❛t❡s✮

❜✉t ♦♥ r❛♥❞♦♠ ❧❡✈❡❧s✳ ❋✉rt❤❡r♠♦r❡✱ ♣✐①❡❧s ♦♥ t❤❡ ✐♠❛❣❡ ♣②r❛♠✐❞s t❤❛t ❤❛✈❡

s❡❧❡❝t❡❞ ♣❛r❡♥ts ✇✐❧❧ ♥♦t ❜❡ ✐♥✐t✐❛❧✐③❡❞✳

❚♦ s❡❛r❝❤ ❢♦r ✉♣♣❡r s❡❧❡❝t❡❞ ♥❡✐❣❤❜♦rs✱ t❤❡ ❛❧❣♦r✐t❤♠ ✜rst ❝❤❡❝❦s ✐❢ t❤❡ ✉♣♣❡r

♥❡✐❣❤❜♦r✐♥❣ ♣✐①❡❧ ♦♥ t❤❡ s❛♠❡ ❧❡✈❡❧ ❛s csparse ✐s ✐♥✐t✐❛❧✐③❡❞✳ ■❢ ✐t ✐s ❛♥❞ ✐t ✐s ❛❧s♦

s❡❧❡❝t❡❞✱ t❤❡ ♠❡r❣❡ ❛❧❣♦r✐t❤♠ r❡t✉r♥s t❤❡ ❛ss♦❝✐❛t❡❞ ♦❜st❛❝❧❡ r❡❣✐♦♥✳ ■❢ t❤❡

♥❡✐❣❤❜♦r ✐s ♥♦t s❡❧❡❝t❡❞ ❛♥❞ ♥♦t ✐♥✐t✐❛❧✐③❡❞✱ ✐t r❡❝✉rs✐✈❡❧② ✐♥s♣❡❝ts t❤❡ ♣❛r❡♥ts

❛♥❞ r❡t✉r♥s t❤❡ ♦❜st❛❝❧❡ r❡❣✐♦♥ ♦❢ t❤❡ ✜rst s❡❧❡❝t❡❞ ❛♥❞ ✐♥✐t✐❛❧✐③❡❞ ♣✐①❡❧✳ ■❢

t❤❡ ♥❡✐❣❤❜♦r ✐s ♥♦t s❡❧❡❝t❡❞ ❜✉t ✐♥✐t✐❛❧✐③❡❞✱ t❤❡ ♠❡r❣❡ ❛❧❣♦r✐t❤♠ r❡❝✉rs✐✈❡❧②

✐♥s♣❡❝ts t❤❡ t✇♦ ❝❤✐❧❞r❡♥ ❝❧♦s❡st t♦ csparse ❛♥❞ r❡t✉r♥s t❤❡ ♦❜st❛❝❧❡ r❡❣✐♦♥ ♦❢

t❤❡ ✜rst ✐♥✐t✐❛❧✐③❡❞ ❛♥❞ s❡❧❡❝t❡❞ ♣✐①❡❧ ❢♦✉♥❞✳ ❚❤❡ s❛♠❡ ♣r♦❝❡❞✉r❡ ✐s ❞♦♥❡ t♦

s❡❛r❝❤ ❢♦r s❡❧❡❝t❡❞ ♥❡✐❣❤❜♦rs ❧❡❢t ♦❢ csparse✳ ❚❤❡ r❡s✉❧t ♦❢ t❤✐s s❡❛r❝❤ ❛r❡ ♥♦♥❡

t♦ t✇♦ ♦❜st❛❝❧❡ r❡❣✐♦♥s✳

csparse ❝❛♥ ❜❡ ♠❡r❣❡❞ ✇✐t❤ ♦♥❡ ♦❢ t❤❡s❡ r❡❣✐♦♥s O ✐❢

meanDist(O)− csparse < patchMergeThreshold ✭✶✺✮

✇❤❡r❡ patchMergeThreshold ✐s ✜①❡❞✳ ❚❤❡ t❤r❡s❤♦❧❞ s❤♦✉❧❞ ❜❡ ❝❤♦s❡♥ s♦ t❤❛t

s✉r❢❛❝❡s ♦❢ ♦❜st❛❝❧❡s ✇❤✐❝❤ ❛r❡ ♣♦s✐t✐♦♥❡❞ ❛t ❛♥ ❛♥❣❧❡ t♦ t❤❡ ❝❛♠❡r❛ ❛r❡ ♠❡r❣❡❞

✐♥t♦ ♦♥❡ ♦❜st❛❝❧❡ r❡❣✐♦♥✳

■❢ ♥♦ s❡❧❡❝t❡❞ ♥❡✐❣❤❜♦rs ❛r❡ ❞❡t❡❝t❡❞✱ t❤❡♥ ❛ ♥❡✇ ♦❜st❛❝❧❡ r❡❣✐♦♥ ✐s ❝r❡❛t❡❞✳

■❢ t✇♦ ♦❜st❛❝❧❡ r❡❣✐♦♥s ❛r❡ ❞❡t❡❝t❡❞ ❛♥❞ csparse ❝❛♥ ❜❡ ♠❡r❣❡❞ ✇✐t❤ ❜♦t❤ ♦❢

t❤❡♠✱ t❤❡♥ t❤❡② ❛r❡ ✜rst ♠❡r❣❡❞ ✇✐t❤ ❡❛❝❤ ♦t❤❡r ❛♥❞ csparse ♠❡r❣❡❞ ✇✐t❤ t❤❡

r❡s✉❧t✐♥❣ ♦❜st❛❝❧❡ r❡❣✐♦♥✳

✷✺

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✹ ❖❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ❏❛♥♥✐s ■❤r✐❣

❋✐❣✉r❡ ✶✸✿ ▼❡r❣✐♥❣ s❡❧❡❝t❡❞ r❡❣✐♦♥s✳ ❚❤❡ s❡❝♦♥❞ ✐♠❛❣❡ ♣❛✐r ✐❧❧✉str❛t❡s t❤❡

❞✐st✐♥❝t✐♦♥ ❜❡t✇❡❡♥ ♦❜st❛❝❧❡ r❡❣✐♦♥s ✇✐t❤ ❞✐✛❡r❡♥t ❛✈❡r❛❣❡ ❞❡♣t❤s✳

✹✳✸ Pr♦❥❡❝t✐♦♥ ♦❢ ♦❜st❛❝❧❡ ❛r❡❛s ✐♥t♦ r❡❧❛t✐✈❡ ❝♦♦r❞✐♥❛t❡s

❚❤❡ ♣r❡✈✐♦✉s st❡♣ r❡s✉❧t❡❞ ✐♥ ♦❜st❛❝❧❡ r❡❣✐♦♥s ♦♥ t❤❡ ❞✐s♣❛r✐t② ♠❛♣ ✇✐t❤ ❜♦✉♥❞✲

✐♥❣ ❜♦①❡s ❝♦♥t❛✐♥✐♥❣ ♦❜st❛❝❧❡ ❢r♦♥ts✽✳ ◆♦✇ ❛ ❜✐r❞✬s ❡②❡ ✈✐❡✇ ♦❢ t❤❡ s❝❡♥❡ ✇✐❧❧

❜❡ ❝r❡❛t❡❞ t♦ ❡♥❛❜❧❡ ♥❛✈✐❣❛t✐♦♥ ❛r♦✉♥❞ t❤❡ ❞❡t❡❝t❡❞ ♦❜st❛❝❧❡s✳ ❚❤❡ ❜♦✉♥❞✐♥❣

❜♦①❡s ❛r❡ t❤❡r❡❢♦r❡ ♣r♦❥❡❝t❡❞ ❢r♦♠ t❤❡ t✇♦✲❞✐♠❡♥s✐♦♥❛❧ ❝♦♦r❞✐♥❛t❡ ❢r❛♠❡ ♦❢

t❤❡ ✐♠❛❣❡s ✐♥t♦ ❛ t✇♦✲❞✐♠❡♥s✐♦♥❛❧ r❡❧❛t✐✈❡ ❝♦♦r❞✐♥❛t❡ ❢r❛♠❡ ✇✐t❤ t❤❡ ❝❡♥t❡r ♦❢

t❤❡ ❝❛r ❛s ✐ts ♦r✐❣✐♥ ❛♥❞ t❤❡ ①✲❛①✐s ❛♥❛❧♦❣ t❤❡ ❝❛r✬s ❞✐r❡❝t✐♦♥ ♦❢ ♠♦✈❡♠❡♥t✳ ❚✇♦

♣♦✐♥ts p1 ❛♥❞ p2 ❛r❡ s❡❧❡❝t❡❞ ❢r♦♠ t❤❡ ❜♦✉♥❞✐♥❣ ❜♦① ♦❢ ❛♥ ♦❜st❛❝❧❡ r❡❣✐♦♥ O✱

♦♥❡ ❢r♦♠ ✐ts ❧❡❢t ❛♥❞ ♦♥❡ ❢r♦♠ ✐ts r✐❣❤t ❜♦r❞❡r✳ ❚❤❡♥ t❤❡② ❛r❡ r❡♣r♦❥❡❝t❡❞ t♦ P1

❛♥❞ P2 ❛s ❞❡s❝r✐❜❡❞ ✐♥ s❡❝t✐♦♥ ✷✳✷✳✹✳ ❚❤❡ ❝♦rr❡❧❛t✐♥❣ ❞✐s♣❛r✐t② t♦ minDist(O)

✐s ✉s❡❞ ❢♦r t❤✐s✱ ❛s ✐t ❜❡❧♦♥❣s t♦ t❤❡ ♣♦✐♥t ♦❢ t❤❡ ♦❜st❛❝❧❡ t❤❛t ✐s ❝❧♦s❡st t♦ t❤❡

❝❛r✳ ❚❤❡ r♦t❛t✐♦♥ ♠❛tr✐① R ❡①t❡♥❞❡❞ ✇✐t❤ t❤❡ tr❛♥s❧❛t✐♦♥ ✈❡❝t♦r t ✐s s❡t t♦

[R|t] =

0 0 1 0

1 0 0 0

0 1 0 h

0 0 0 1

✭✶✻✮

✽❚❤❡ ♦❜st❛❝❧❡ r❡❣✐♦♥s ❝♦♥t❛✐♥ ♣❛t❝❤❡s ♦♥ Idist ❛s t❤❡② ❛r❡ s❡❧❡❝t❡❞ t❤r♦✉❣❤ ♣✐①❡❧s ♦♥✐♠❛❣❡s ♦♥ t❤❡ ✐♠❛❣❡ ♣②r❛♠✐❞s ❝r❡❛t❡❞ ❢r♦♠ t❤❡ ❞✐st❛♥❝❡ ♠❛♣✳ ❚❤❡ s❛♠❡ ♣❛t❝❤❡s ♣❧❛❝❡❞ ♦♥I ❞❡s❝r✐❜❡ t❤❡ s❛♠❡ ♦❜st❛❝❧❡ ❢r♦♥ts✱ ♦♥❧② t❤❡ r❡♣r❡s❡♥t❛t✐♦♥ ♦❢ t❤❡ ❞❡♣t❤ ✐♥❢♦r♠❛t✐♦♥ ❞✐✛❡rs✳

✷✻

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✺ ❊✈❛❧✉❛t✐♦♥ ❏❛♥♥✐s ■❤r✐❣

✇❤❡r❡ h ✐s t❤❡ ❤❡✐❣❤t ❛t ✇❤✐❝❤ t❤❡ ❝❛♠❡r❛ ✐s ❛tt❛❝❤❡❞ t♦ t❤❡ s❡♥s♦r ♣♦❧❡ ♦❢ t❤❡

❝❛r✳ ❚❤❡ ③✲❝♦♠♣♦♥❡♥ts ♦❢ P1 ❛♥❞ P2 ❛r❡ r❡♠♦✈❡❞ ❛s t❤❡ ❝❛r ♦♥❧② ♥❛✈✐❣❛t❡s

♦♥ ❛ t✇♦✲❞✐♠❡♥s✐♦♥❛❧ ♠❛♣✳

■♥ t❤❡ ❜✐r❞✬s ❡②❡ ♣❡rs♣❡❝t✐✈❡ ♦❢ t❤❡ s❝❡♥❡ s✉rr♦✉♥❞✐♥❣ t❤❡ ❝❛r t❤❡ ❜♦✉♥❞✐♥❣

❜♦①❡s r❡s✉❧t✐♥❣ ❢r♦♠ t❤❡ ❜❧♦❜ ❞❡t❡❝t✐♦♥ s❤♦✇ ✉♣ ❛s ❧✐♥❡ s❡❣♠❡♥ts ♦♥ t❤❡ ❣r♦✉♥❞✳

❊❛❝❤ ♦❢ t❤❡s❡ ❧✐♥❡ s❡❣♠❡♥ts r❡♣r❡s❡♥ts ❛♥ ♦❜st❛❝❧❡ s✉r❢❛❝❡ ❢❛❝✐♥❣ t❤❡ ❝❛♠❡r❛✳

❚❤✐s s✐♠♣❧❡ r❡♣r❡s❡♥t❛t✐♦♥ ❞❡s❝r✐❜❡s t❤❡ ❞✐st❛♥❝❡ ♦❢ t❤❡ ❝❧♦s❡st ♣♦✐♥t ♦❢ t❤❡

♦❜st❛❝❧❡ t♦ t❤❡ ❝❛r ❛♥❞ t❤❡ t❤❡ ✇✐❞t❤ ♦❢ ✐ts ❢r♦♥t s✉r❢❛❝❡✳

❚❤❡ s✉r❢❛❝❡ ♦❢ ♦❜st❛❝❧❡ ❢r♦♥ts t❡♥❞ t♦ r❡s✉❧t ✐♥ ✐♥✈❛❧✐❞ r❡❣✐♦♥s ♦♥ t❤❡ ❞✐s✲

♣❛r✐t② ♠❛♣ ❛s ♦♥❧② ❛ ❧♦✇ ❛♠♦✉♥t ♦❢ ❢❡❛t✉r❡s ❝❛♥ ❜❡ ❢♦✉♥❞ ❤❡r❡✳ ❚❤✐s ✐s

❡s♣❡❝✐❛❧❧② tr✉❡ ❛t ✐♥❝r❡❛s✐♥❣ ❞✐st❛♥❝❡s ❛♥❞ str♦♥❣❧② ❞❡♣❡♥❞❡♥t ♦♥ t❤❡ q✉❛❧✐t②

♦❢ t❤❡ ❝❛♠❡r❛✬s st❡r❡♦ ❝❛❧✐❜r❛t✐♦♥✳ ▲❡❢t ❛♥❞ r✐❣❤t ♦❜st❛❝❧❡ ❜♦r❞❡rs r❡s✉❧t ✐♥

❡❛s② t♦ ✜♥❞ ❢❡❛t✉r❡s ♦♥ t❤❡ st❡r❡♦ ❝❛♠❡r❛✬s ✐♠❛❣❡s ❛♥❞ t❤❡r❡❢♦r❡ st✐❧❧ ♣r♦✲

❞✉❝❡ ✈❛❧✐❞ ❞✐s♣❛r✐t✐❡s✳ ❯♥❞❡r t❤❡s❡ ❝♦♥❞✐t✐♦♥s✱ ❛ s✐♥❣❧❡ ♦❜st❛❝❧❡ ❢r♦♥t ✐s ♦❢t❡♥

❞❡t❡❝t❡❞ ❛s t✇♦ s❡♣❛r❛t❡ ❢r♦♥ts✳ ❆ ♠❡r❣❡ st❡♣ ✐s ❛♣♣❧✐❡❞ t♦ ❝♦✉♥t❡r❛❝t t❤✐s

❞❡❝♦♠♣♦s✐t✐♦♥✳ ❚❤❡ ♠❛①✐♠✉♠ ❞✐st❛♥❝❡ ❢♦r ♠❡r❣✐♥❣ t✇♦ ♦❢ ♦❜st❛❝❧❡ ❢r♦♥ts r❡♣✲

r❡s❡♥t❡❞ ❛s ❧✐♥❡ s❡❣♠❡♥ts ✐s ❣✐✈❡♥ ❜② t❤❡ t❤r❡s❤♦❧❞s depthsMergeThreshold

❛♥❞ horizontalMergeThreshold✳ ❚❤❡ ❧❛tt❡r ❝❛♥ ❜❡ s❡t t♦ t❤❡ ❝❛r✬s ✇✐❞t❤ ❛s

❛♥② ❣❛♣ ❜❡t✇❡❡♥ ♦❜st❛❝❧❡s s♠❛❧❧❡r t❤❛♥ t❤✐s ✇✐❧❧ ❜❡ ✐♠♣❛ss❛❜❧❡✳

❋✐❣✉r❡ ✶✹✿ ❆ ❞❡t❡❝t❡❞ ♦❜st❛❝❧❡ r❡❣✐♦♥ ♦♥ t❤❡ ✐♠❛❣❡ ❛♥❞ t❤❡ s❛♠❡ ♦❜st❛❝❧❡ ✐♥ r❡❧❛t✐✈❡

❝♦♦r❞✐♥❛t❡s✳

✺ ❊✈❛❧✉❛t✐♦♥

❚❤❡ ❢♦❧❧♦✇✐♥❣ s❡❝t✐♦♥ ✇✐❧❧ ❡✈❛❧✉❛t❡ t❤❡ ✐♠♣❧❡♠❡♥t❡❞ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ♠❡t❤♦❞✳

❚♦ ❞♦ t❤✐s✱ ✐t ✐s r❡❧❡✈❛♥t t♦ t❡st t❤❡ ♣r♦❜❛❜✐❧✐t② t❤❛t ❛♥ ♦❜st❛❝❧❡ ✐s ❞❡t❡❝t❡❞

✷✼

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✺ ❊✈❛❧✉❛t✐♦♥ ❏❛♥♥✐s ■❤r✐❣

✐♥ ❣❡♥❡r❛❧✱ ❛s ✇❡❧❧ ❛s t❤❡ ❛❝❝✉r❛❝② ✇✐t❤ ✇❤✐❝❤ ✐ts ❧♦❝❛t✐♦♥ ❛♥❞ ✇✐❞t❤ ❛r❡ ❞❡✲

t❡r♠✐♥❡❞✳ ❚❤r❡❡ ❡①♣❡r✐♠❡♥ts ✇❤❡r❡ ❡①❡❝✉t❡❞ t❤❛t ❢♦❝✉s ♦♥ t❤❡s❡ ❛s♣❡❝ts ♦❢

♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥✳ ❚❤❡✐r r❡s✉❧ts ✇✐❧❧ ❜❡ ♣r❡s❡♥t❡❞ ❛❢t❡r t❤❡ ❞❡s❝r✐♣t✐♦♥ ♦❢ t❤❡

❣❡♥❡r❛❧ t❡st s❡t✉♣✳

❚❤❡ ❧✐♠✐t❡❞ ❝♦♠♣✉t❛t✐♦♥❛❧ ♣♦✇❡r ♣r♦✈✐❞❡❞ ❜② t❤❡ ❖❞r♦✐❞✲❳❯ ❛♥❞ t❤❡ ♥❡❡❞ ❢♦r

❢❛st ❡①❡❝✉t✐♦♥ t✐♠❡ ❤❛✈❡ ❛❧r❡❛❞② ❜❡❡♥ ♠❡♥t✐♦♥❡❞✳ ❘✉♥♥✐♥❣ t❤❡ ❛❧❣♦r✐t❤♠ ✇✐t❤

❧❡ss t❤❛♥ ✷✵ ❍③ ✇♦✉❧❞ ♥♦t ♠❛❦❡ ✉s❡ ♦❢ ❛❧❧ ❢r❛♠❡s r❡❝❡✐✈❡❞ ❜② t❤❡ st❡r❡♦ ❝❛♠❡r❛

❛♥❞ ♣r♦❜❛❜❧② ❝♦♠♣❧✐❝❛t❡ t❤❡ t❛s❦ ♦❢ ❛✈♦✐❞✐♥❣ ♦❜st❛❝❧❡s✳ ❚❤❡r❡❢♦r❡ t❤❡ ♦✈❡r❛❧❧

r✉♥t✐♠❡ ♦❢ t❤❡ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ♠❡t❤♦❞ ✇✐❧❧ ❜❡ t❡st❡❞ ✐♥ ❛ ❢♦✉rt❤ ❡①♣❡r✐♠❡♥t

✇✐t❤ r❡s✉❧ts ♣r❡s❡♥t❡❞ ✐♥ s❡❝t✐♦♥ ✺✳✺✳

❚❤r♦✉❣❤♦✉t t❤✐s s❡❝t✐♦♥ ♦♥❡ ❤❛s t♦ ❦❡❡♣ ✐♥ ♠✐♥❞ t❤❛t t❤❡ ❞❡✈❡❧♦♣❡❞ ❛♣♣r♦❛❝❤

t♦ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ✐s ❞❡♣❡♥❞❡♥t ♦♥ t❤❡ q✉❛❧✐t② ♦❢ ❞✐s♣❛r✐t② ♠❛♣s r❡❝❡✐✈❡❞

❢r♦♠ t❤❡ st❡r❡♦ ❝❛♠❡r❛✳ ❚❤✐s ✐s ❡s♣❡❝✐❛❧❧② tr✉❡ ❛s t❤❡ ♥✉♠❜❡r ♦❢ ❢❡❛t✉r❡s

s✉♣♣❧✐❡❞ ❜② t❤❡ ❧❡❢t ❛♥❞ r✐❣❤t ❝❛♠❡r❛ ✐♠❛❣❡s ❛♥❞ ♥❡❡❞❡❞ t♦ ♣❡r❢♦r♠ st❡r❡♦

✈✐s✐♦♥ ✐s ❧♦✇ ✐♥ t❤❡ r❡❞✉❝❡❞ ❡♥✈✐r♦♥♠❡♥t ❞❡s❝r✐❜❡❞ ❜② t❤❡ ❈❛r♦❧♦✲❈✉♣ r✉❧❡s✳

✺✳✶ ●❡♥❡r❛❧ t❡st s❡t✉♣

❆❧❧ ❢♦✉r ❡①♣❡r✐♠❡♥ts ✇❤❡r❡ ❡①❡❝✉t❡❞ ✐♥ ❛♥ ❡♥✈✐r♦♥♠❡♥t t❤❛t ❝♦♥❢♦r♠s t♦ t❤❡

r✉❧❡s ♦❢ t❤❡ ❈❛r♦❧♦✲❈✉♣✳ ❙✐♥❝❡ t❤❡ ♥❡✇ P♦✇❡r❜♦❛r❞ ♥❡❡❞❡❞ t♦ ♣♦✇❡r ❖❞r♦✐❞✲

❳❯ ❛♥❞ t❤❡ st❡r❡♦ ❝❛♠❡r❛ ✐s st✐❧❧ ✉♥❞❡r ❞❡✈❡❧♦♣♠❡♥t✱ ❛ t❡st st❛♥❞ ✇❛s ❜✉✐❧t t♦

r❡❝♦r❞ ❛❧❧ ✐♠❛❣❡s ✉s❡❞ ❢♦r t❤❡ ❢♦❧❧♦✇✐♥❣ ❡①♣❡r✐♠❡♥ts✳ ❚❤❡ st❡r❡♦ ❝❛♠❡r❛ ✇❛s

✐♥st❛❧❧❡❞ ♦♥ t❤❡ t❡st st❛♥❞ ✇✐t❤ t❤❡ s❛♠❡ ❤❡✐❣❤t ❛♥❞ ♦r✐❡♥t❛t✐♦♥ ❛s ✐❢ ❛tt❛❝❤❡❞

t♦ t❤❡ ❝❛r✬s s❡♥s♦r ♣♦❧❡✳ ❋♦r ❡①♣❡r✐♠❡♥ts ✶ t♦ ✸✱ ♠❡❛s✉r❡♠❡♥ts ✇❡r❡ t❛❦❡♥

✇✐t❤ ❛♥ ♦❜st❛❝❧❡ ♣❧❛❝❡❞ ✐♥ ❢r♦♥t ♦❢ t❤❡ ❝❛♠❡r❛ ❛t ❞✐st❛♥❝❡s ❜❡t✇❡❡♥ ✶ ♠❡t❡rs

t♦ ✺ ♠❡t❡rs✳ ❚❤❡ ❧♦❝❛t✐♦♥ ♦❢ ❛r❡❛s ✐♥ t❤❡ ✐♠❛❣❡ ✇❤✐❝❤ s❤♦✇ ♦❜st❛❝❧❡s ♠❛②

✐♥✢✉❡♥❝❡ t❤❡ r❡s✉❧t ♦❢ t❤❡ ❛❧❣♦r✐t❤♠✳ ❚❤❡r❡❢♦r❡ ❛ s❡❝♦♥❞ s❡r✐❡s ♦❢ t❡sts ✇❛s

❡①❡❝✉t❡❞ ♦✈❡r t❤❡ s❛♠❡ ❞✐st❛♥❝❡s ❜✉t ✇✐t❤ t❤❡ ♦❜st❛❝❧❡ ✹✵ ❝♠ ♦✛s❡t ❢r♦♠ ✐ts

♦r✐❣✐♥❛❧ ♣♦s✐t✐♦♥✳ ❚❤❡ r❡s✉❧ts s❤♦✇♥ ❜❡❧♦✇ ❛r❡ ❜❛s❡❞ ♦♥ t❤❡ ❝♦♠❜✐♥❡❞ ❞❛t❛ s❡t

♦❢ ❜♦t❤ t❡st s❡r✐❡s✳

❋♦r ❡①♣❡r✐♠❡♥t ✹✱ ③❡r♦ t♦ ❢♦✉r ♦❜st❛❝❧❡s ✇❤❡r❡ ♣❧❛❝❡❞ ✐♥ ❢r♦♥t ♦❢ t❤❡ ❝❛♠❡r❛ ❛t

❛ ❞✐st❛♥❝❡ ♦❢ ✷ ♠❡t❡rs t♦ t❡st t❤❡ ❞❡♣❡♥❞❡♥❝② ❜❡t✇❡❡♥ t❤❡ ♥✉♠❜❡r ♦❢ ♦❜st❛❝❧❡s

❛♥❞ t❤❡ ❛❧❣♦r✐t❤♠✬s r✉♥t✐♠❡✳

❋♦❧❧♦✇✐♥❣ ❣♦♦❞ ✈❛❧✉❡s ❢♦r t❤❡ ♣❛r❛♠❡t❡rs ✇❤❡r❡ ❡♠♣✐r✐❝❛❧❧② ❞❡t❡r♠✐♥❡❞ ❜❡❢♦r❡

r❡❝♦r❞✐♥❣ t❤❡ ❞❛t❛ s❡ts✿

✷✽

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✺ ❊✈❛❧✉❛t✐♦♥ ❏❛♥♥✐s ■❤r✐❣

♣❛r❛♠❡t❡r ✈❛❧✉❡♠❛①▲❡✈❡❧ ✽st❛rt▲❡✈❡❧ ✷❤♦r✐③♦♥❨ ✷✶✵♠✐♥❖❜st❛❝❧❡❍❡✐❣❤t ✵✳✵✾ ♠✜①❡❞■♥s♣❡❝t❚❤r❡s❤♦❧❞ ✵✳✵✽ ♠♣❛t❝❤▼❡r❣❡❚❤r❡s❤♦❧❞ ✵✳✸ ♠❞❡♣t❤▼❡r❣❡❚❤r❡s❤♦❧❞ ✵✳✶ ♠❤♦r✐③♦♥t❛❧▼❡r❣❡❚❤r❡s❤♦❧❞ ✵✳✸✺ ♠

maxLevels ✐s t❤❡ ♠♦st ✐♥✢✉❡♥t✐❛❧ ♣❛r❛♠❡t❡r✳ ■t ❞❡t❡r♠✐♥❡s t❤❡ ♠❛①✐♠✉♠

❤❡✐❣❤t ♦❢ ❛❧❧ ✐♠❛❣❡ ♣②r❛♠✐❞s ❛♥❞✱ ✇✐t❤ t❤✐s✱ ♣♦t❡♥t✐❛❧ ❛❝❝✉r❛❝② ❢♦r ❛♣♣r♦①✐♠❛✲

t✐♦♥s ♦❢ ♦❜st❛❝❧❡ s✉r❢❛❝❡s t❤r♦✉❣❤ t❤❡ ♥✉♠❜❡r ❛♥❞ s✐③❡ ♦❢ ♣❛t❝❤❡s ♦♥ t❤❡✐r ❤✐❣❤✲

❡st ❧❡✈❡❧✳ ❆s t❤❡ ♥✉♠❜❡r ♦❢ t❤❡s❡ ♣❛t❝❤❡s ✐♥❝r❡❛s❡s ❡①♣♦♥❡♥t✐❛❧❧② ✇✐t❤ ❡❛❝❤ ❛❞✲

❞✐t✐♦♥❛❧ ❧❡✈❡❧✱ maxLevel ❛❧s♦ ❤❛s ❛♥ ❡①♣♦♥❡♥t✐❛❧ ✐♠♣❛❝t ♦♥ t❤❡ ✇♦rst✲❝❛s❡ r✉♥✲

t✐♠❡✳ maxLevel ♦❢ ✽ s❡❡♠s t♦ ❣✐✈❡ ❛ ❣♦♦❞ tr❛❞❡✲♦❢ ❜❡t✇❡❡♥ ❛❝❝✉r❛❝② ❛♥❞ r✉♥✲

t✐♠❡ ✇❤✐❧❡ r✉♥♥✐♥❣ t❤❡ ❛❧❣♦r✐t❤♠ ♦♥ ❛♥ ❖❞r♦✐❞✲❳❯ ✇✐t❤ ✐ts ❧✐♠✐t❡❞ r❡s♦✉r❝❡s✳

❆ minObstacleHeight ♦❢ ✵✳✵✾ ♠❡t❡rs ❝♦♠❡s ✇✐t❤ t❤❡ ♠✐♥✐♠❛❧ ❤❡✐❣❤t ♦❢ ♦❜✲

st❛❝❧❡s ❣✐✈❡♥ ❜② t❤❡ ❈❛r♦❧♦✲❈✉♣ r✉❧❡s✳ ❚❤❡ patchMergeThreshold ♦❢ ✵✳✸ ♠

❡♥s✉r❡s t❤❛t s❡❧❡❝t❡❞ ✐♠❛❣❡ ♣❛t❝❤❡s ❢♦✉♥❞ ♦♥ ♦❜st❛❝❧❡s ♣❧❛❝❡❞ ❛t ❛♥ ❛♥❣❧❡ t♦ t❤❡

❝❛♠❡r❛ ✇✐❧❧ ❜❡ ♠❡r❣❡❞ ✐♥t♦ t❤❡ s❛♠❡ ♦❜st❛❝❧❡ r❡❣✐♦♥✳ fixedInspectThreshold

✇❛s s❡t t♦ ✵✳✵✽ ♠❡t❡rs ❛s t❤✐s ✈❛❧✉❡ r❡s✉❧ts ✐♥ ❛ ❣♦♦❞ ❞❡t❡❝t✐♦♥ ♦❢ ♦❜st❛❝❧❡

❜♦r❞❡rs ❝♦♠❜✐♥❡❞ ✇✐t❤ ❧♦✇ ❢r❛❣♠❡♥t❛t✐♦♥ ♦❢ ♣❛t❝❤❡s ♦♥ ♦❜st❛❝❧❡s✳

✺✳✷ ❊①♣❡r✐♠❡♥t ✶✿ ❉❡t❡❝t✐♦♥ r❛t❡

▲❡t ❛♥ ♦❜st❛❝❧❡ ♣❧❛❝❡❞ ✐♥ ❢r♦♥t ♦❢ t❤❡ ❝❛r ❝♦✉♥t ❛s ❞❡t❡❝t❡❞ ✐❢ t❤❡ ♦❜st❛❝❧❡

❞❡t❡❝t✐♦♥ ♠❡t❤♦❞ r❡s✉❧ts ✐♥ ♦♥❡ ♦r ♠✉❧t✐♣❧❡ ❞❡t❡❝t❡❞ ♦❜st❛❝❧❡ ❢r♦♥ts t❤❛t ❛t

❧❡❛st ♣❛rt❧② ❞❡s❝r✐❜❡ t❤❡ ♣❤②s✐❝❛❧ ♦❜st❛❝❧❡✳ ❚❤❡ ❞❡t❡❝t✐♦♥ r❛t❡ t❤❡♥ ✐s t❤❡

♣❡r❝❡♥t❛❣❡ ♦❢ ❢r❛♠❡s ❢♦r ✇❤✐❝❤ t❤❛t ✐s tr✉❡ ❝♦♠♣❛r❡❞ ❛❣❛✐♥st t❤❡ t♦t❛❧ ♥✉♠❜❡r

♦❢ ❢r❛♠❡s✳

❋✐❣✉r❡ ✶✺ s❤♦✇s t❤❛t t❤❡ ❞❡t❡❝t✐♦♥ r❛t❡ ❛t ❝❧♦s❡ r❛♥❣❡s ✉♣ t♦ ✸ ♠❡t❡rs ✐s ❛❧♠♦st

❛t ✶✵✵✪ ❛♥❞ ❞r♦♣s ❢♦r ❧❛r❣❡r ❞✐st❛♥❝❡s✳ ❖♥❡ r❡❛s♦♥ ❢♦r t❤✐s r❡s✉❧t ❝♦✉❧❞ ❜❡

t❤❛t t❤❡ r❡❣✐♦♥s ✇✐t❤ ❤✐❣❤ ❞✐st❛♥❝❡s ♦♥ t❤❡ ❞✐st❛♥❝❡ ♠❛♣ ❜❡❝♦♠❡ s♠❛❧❧❡r ❛t

❤✐❣❤❡r ❞✐st❛♥❝❡s✳ ❚❤✐s ❡✛❡❝t ❜❡❝♦♠❡s ❡✈❡♥ str♦♥❣❡r ❛s s♠❛❧❧❡r ❢❡❛t✉r❡s ♦♥ t❤❡

❡✈❡♥ s✉r❢❛❝❡s ♦❢ ♦❜st❛❝❧❡ ❜♦①❡s ✇✐❧❧ ♥♦t ❜❡ ❞❡t❡❝t❡❞ ❛t ❧❛r❣❡r ❞✐st❛♥❝❡s✳ ❚❤❡

❛❧❣♦r✐t❤♠ t❤❡♥ ❞♦❡s ♥♦t s❡❧❡❝t t❤❡s❡ r❡❣✐♦♥s ❜❡❝❛✉s❡ t❤❡ ♠❡❛♥ ❞✐st❛♥❝❡ ✈❛❧✉❡s

r❡♣r❡s❡♥t❡❞ ❜② ♣✐①❡❧s ♦♥ ❧♦✇❡r ❧❡✈❡❧s ♦❢ t❤❡ ❛ss♦❝✐❛t❡❞ ✐♠❛❣❡ ♣②r❛♠✐❞s ❛r❡ t♦♦

✷✾

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❋✐❣✉r❡ ✶✺

❧♦✇✳

❖♥❡ ❤❛s t♦ ❦❡❡♣ ✐♥ ♠✐♥❞ t❤❛t t❤❡s❡ t❡st ❛r❡ ❞♦♥❡ ✇✐t❤♦✉t ✜❧t❡r✐♥❣ ♦r tr❛❝❦✐♥❣

♦❜st❛❝❧❡s ♦✈❡r ♠✉❧t✐♣❧❡ ❢r❛♠❡s✱ s✐♥❝❡ t❤✐s ✇♦✉❧❞ ❣♦ ❜❡②♦♥❞ t❤❡ s❝♦♣❡ ♦❢ t❤✐s

✇♦r❦✳ ❊✈❡♥ ✇✐t❤ ❛ ❞❡t❡❝t✐♦♥ r❛t❡ ♦❢ s❧✐❣❤t❧② ❜❡❧♦✇ ✺✵✪ ❛t ❛ ❞✐st❛♥❝❡ ♦❢ ✺

♠❡t❡rs✱ tr❛❝❦✐♥❣ ♦❜st❛❝❧❡ ❢r♦♥ts ♦✈❡r ♠✉❧t✐♣❧❡ ❢r❛♠❡s ✇♦✉❧❞ r❡s✉❧t ✐♥ ❛ r❡❧✐❛❜❧❡

❞❡t❡❝t✐♦♥✳

✺✳✸ ❊①♣❡r✐♠❡♥t ✷✿ ▼❡❛s✉r❡❞ ❞✐st❛♥❝❡s

❚❤❡ ❛❝❝✉r❛❝② ♦❢ ♠❡❛s✉r❡❞ ❞✐st❛♥❝❡s ❜❡t✇❡❡♥ ♦❜st❛❝❧❡ ❛♥❞ ❝❛r ✐s ♦♥❡ ♦❢ t❤❡

♠♦st ✐♠♣♦rt❛♥t ❢❛❝t♦rs ❢♦r ❧❛t❡r ❜❡❤❛✈✐♦r t❤❛t ♠❡❛♥t ❛✈♦✐❞ ❝♦❧❧✐s✐♦♥s✳ ❆s t❤❡

♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ♠❡t❤♦❞ ♣r❡s❡♥t❡❞ ✐♥ s❡❝t✐♦♥ ✹ ✇♦r❦s ✇✐t❤ ❞✐s♣❛r✐t② ♠❛♣s

r❡❝❡✐✈❡❞ ❢r♦♠ t❤❡ st❡r❡♦ ❝❛♠❡r❛✱ ✐t r❡❧✐❡s ♦♥ t❤❡ ❛❝❝✉r❛❝② ♦❢ ❞❡♣t❤ ✐♥❢♦r♠❛t✐♦♥

❝♦♥t❛✐♥❡❞ ✐♥ t❤❡s❡ ♠❛♣s✳ ❚❤❛t ✐s ✇❤② t❤❡ ❛❝❝✉r❛❝② ♦❢ ♣r❡❞✐❝t✐♥❣ ❞✐st❛♥❝❡s

❜❡t✇❡❡♥ ♦❜st❛❝❧❡s ❛♥❞ t❤❡ ❝❛r ✐s ❡s♣❡❝✐❛❧❧② ❞❡♣❡♥❞❡♥t ♦♥ t❤❡ q✉❛❧✐t② ♦❢ t❤❡

st❡r❡♦ ❝❛❧✐❜r❛t✐♦♥ ✉s❡❞✳

❋✐❣✉r❡ ✶✻ s❤♦✇s t❤❡ r❡s✉❧ts ❢♦r ♦❜st❛❝❧❡s ♣❧❛❝❡❞ ❛t ❞✐st❛♥❝❡s ♦❢ ✶ t♦ ✺ ♠❡t❡rs t♦

t❤❡ ❝❛r✳ ❈♦♥s♣✐❝✉♦✉s❧②✱ ❡✈❡r② ♠❡❛s✉r❡❞ ❞✐st❛♥❝❡ ✐s s♠❛❧❧❡r t❤❛♥ t❤❡ ❛ss♦❝✐❛t❡❞

❣r♦✉♥❞ tr✉t❤✳ ❚❤❡ ❡rr♦r s❡❡♠s t♦ ❜❡ ❝♦♠♣♦s❡❞ ♦❢ t✇♦ ❢❛❝t♦rs✳ ❚❤❡ ✜rst ✐s t❤❡

❣❛♣ ❜❡t✇❡❡♥ t❤❡ ♠❡❛♥ ♦❢ ♠❡❛s✉r❡❞ ❞✐st❛♥❝❡s ❛♥❞ t❤❡ ❣r♦✉♥❞ tr✉t❤✳ ❚❤❡ s❡❝♦♥❞

✐s ❞❡s❝r✐❜❡❞ t❤r♦✉❣❤ t❤❡ st❛♥❞❛r❞ ❞❡✈✐❛t✐♦♥ ❜② ✇❤✐❝❤ t❤❡ ♠❡❛s✉r❡♠❡♥ts ❛r❡

s♣r❡❛❞ ❛r♦✉♥❞ t❤✐s ♠❡❛♥✳ ❇♦t❤ ✐♥❝r❡❛s❡ ✇✐t❤ ❤✐❣❤❡r ❞✐st❛♥❝❡s ❜❡t✇❡❡♥ ♦❜st❛❝❧❡

❛♥❞ ❝❛♠❡r❛✳ ❚❤❡ ♠❡❛♥s ❛♥❞ st❛♥❞❛r❞ ❞❡✈✐❛t✐♦♥ ❢♦r ❡❛❝❤ s❡t ♦❢ ❞❛t❛ s❤♦✇♥ ✐♥

✜❣✉r❡ ✶✼ s✉♣♣♦rt t❤✐s✳

✸✵

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❋✐❣✉r❡ ✶✻✿ ▼❡❛s✉r❡❞ ❞✐st❛♥❝❡ ❜❡t✇❡❡♥ ♦❜st❛❝❧❡ ❛♥❞ ❝❛r✳ ❚❤❡ ❣r♦✉♥❞ tr✉t❤ ✐s ♠❛r❦❡❞

✐♥ r❡❞✳

♦❜st❛❝❧❡ ❞✐st❛♥❝❡ ✐♥ ♠

✶ ✷ ✸ ✹ ✺

♠❡❛♥ ❞✐st❛♥❝❡ ✐♥ ♠ ✵✳✾✽✸ ✶✳✾✺✼ ✷✳✾✵✹ ✸✳✼✻✻ ✹✳✻✷✺

st❛♥❞❛r❞ ❞❡✈✐❛t✐♦♥ ✐♥ ♠ ✵✳✵✵✶ ✵✳✵✵✺ ✵✳✵✶✸ ✵✳✵✷✶ ✵✳✵✺✸

❋✐❣✉r❡ ✶✼✿ ▼❡❛♥ ❞✐st❛♥❝❡ ❛♥❞ st❛♥❞❛r❞ ❞❡✈✐❛t✐♦♥ ❢♦r ♦❜st❛❝❧❡s ♣❧❛❝❡❞ ✐♥ ❢r♦♥t ♦❢ t❤❡

❝❛♠❡r❛ ✐♥ ❞✐st❛♥❝❡s ❢r♦♠ ✶ ♠ t♦ ✺ ♠✳

❚❤❡s❡ ✈❛❧✉❡s ❛❞❞✐t✐♦♥❛❧❧② s❤♦✇ t❤❛t st❛♥❞❛r❞ ❞❡✈✐❛t✐♦♥ ❢♦r ❡❛❝❤ s❡t ♦❢ ♠❡❛✲

s✉r❡❞ ❞✐st❛♥❝❡s st❛②s s♠❛❧❧ ✐♥ ❣❡♥❡r❛❧✱ ❛♥❞ ✐s ♥❡❣❧✐❣✐❜❧❡ ❢♦r ❞✐st❛♥❝❡s ♦❢ ❧❡ss

t❤❛♥ ✹ ♠❡t❡rs✳ ❚❤❡ ✐♥❝r❡❛s❡ ♦✈❡r ❞✐st❛♥❝❡ ♦❢ t❤❡ ❣❛♣ ❜❡t✇❡❡♥ t❤❡ ♠❡❛s✉r❡❞

♠❡❛♥ ❞✐st❛♥❝❡ ❛♥❞ t❤❡ ❣r♦✉♥❞ tr✉t❤ s❡❡♠s t♦ r❡s✉❧t ❢r♦♠ ❛ s②st❡♠❛t✐❝ ❡rr♦r✳

❋✐♥❞✐♥❣ ✐ts ♦r✐❣✐♥ ✇♦✉❧❞ ♥❡❡❞ ❛ ❝❧♦s❡r ✐♥s♣❡❝t✐♦♥ ♦❢ t❤❡ ❝❛♠❡r❛s ✐♥tr✐♥s✐❝ ♣❛✲

r❛♠❡t❡rs ❛♥❞ t❤❡ tr❛♥s❢♦r♠❛t✐♦♥s ♣❡r❢♦r♠❡❞ ❜② t❤❡ ❝❛♠❡r❛s s♦❢t✇❛r❡✱ ❛ t❛s❦

❝♦♠♣❧✐❝❛t❡❞ ❜② t❤❡ ♠✐ss✐♥❣ ❞♦❝✉♠❡♥t❛t✐♦♥ ♦❢ t❤❡ ❱✐s❑♦s✲❙♠❛rt❈❛♠✳ ■t t❤❡r❡✲

❢♦r❡ ❣♦❡s ❜❡②♦♥❞ t❤❡ s❝♦♣❡ ♦❢ t❤✐s ✇♦r❦✳ ❆ s❤♦rt✲t❡r♠ s♦❧✉t✐♦♥ ✇♦✉❧❞ ❜❡ t♦

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✺ ❊✈❛❧✉❛t✐♦♥ ❏❛♥♥✐s ■❤r✐❣

♠♦❞❡❧ t❤❡ ❣❛♣ ❜❡t✇❡❡♥ ♠❡❛♥ ❛♥❞ ❣r♦✉♥❞ tr✉t❤ ❜② ❝✉r✈❡ ✜tt✐♥❣✳

✺✳✹ ❊①♣❡r✐♠❡♥t ✸✿ ❲✐❞t❤ ❛♥❞ ❤♦r✐③♦♥t❛❧ ❞✐s♣❧❛❝❡♠❡♥t ♦❢

❞❡t❡❝t❡❞ ♦❜st❛❝❧❡ ❢r♦♥ts

❋✐❣✉r❡ ✶✽✿ ❚❤❡ ❜♦✉♥❞✐♥❣ ❜♦① ♣❧❛❝❡❞ ❛r♦✉♥❞ ❛♥ ♦❜st❛❝❧❡ ❛♥❞ t❤❡ ♣r♦❥❡❝t❡❞ ♦❜st❛❝❧❡

❢r♦♥t ✉s❡❞ ❛s r❡❢❡r❡♥❝❡✳

❚❤✐s ❡①♣❡r✐♠❡♥t ❢♦❝✉s❡s ♦♥ t❤❡ ✇✐❞t❤ ❛♥❞ ❤♦r✐③♦♥t❛❧ ❧♦❝❛t✐♦♥ ♦❢ ❞❡t❡❝t❡❞ ♦❜✲

st❛❝❧❡ ❢r♦♥ts✳ ❆ ❜♦✉♥❞✐♥❣ ❜♦① ✇❛s ♠❛♥✉❛❧❧② ♣❧❛❝❡❞ ❛r♦✉♥❞ ♦❜st❛❝❧❡s ♣r❡s❡♥t❡❞

t♦ t❤❡ ❝❛♠❡r❛ ❛♥❞ ♣r♦❥❡❝t❡❞ ✐♥t♦ t✇♦✲❞✐♠❡♥s✐♦♥❛❧ ❝♦♦r❞✐♥❛t❡s r❡❧❛t✐✈❡ t♦ t❤❡

❝❛r ✭s❡❡ ✜❣✉r❡ ✶✽✮✳ ❚❤❡ ♣r♦❥❡❝t❡❞ r❡❢❡r❡♥❝❡ ✇❛s ✉s❡❞ t♦ ❝♦♠♣❛r❡ t❤❡ ✇✐❞t❤ ♦❢

❞❡t❡❝t❡❞ ♦❜st❛❝❧❡ ❢r♦♥ts ❛❣❛✐♥st t❤❡✐r ❛❝t✉❛❧ ✇✐❞t❤✳ ❆❞❞✐t✐♦♥❛❧❧②✱ t❤❡ ❝❡♥t❡rs ♦❢

t❤❡ r❡❢❡r❡♥❝❡s ❛♥❞ ♦❢ t❤❡ ❞❡t❡❝t❡❞ ♦❜st❛❝❧❡ ❢r♦♥ts ✇❤❡r❡ ❝♦♠♣❛r❡❞ t♦ ♠❡❛s✉r❡

t❤❡ ❤♦r✐③♦♥t❛❧ ❞✐s♣❧❛❝❡♠❡♥t ♦❢ ❞❡t❡❝t❡❞ ❢r♦♥ts✳

❋✐❣✉r❡ ✶✾ s❤♦✇s t❤❡ r❡s✉❧ts ♦❢ t❤❡ ❡①♣❡r✐♠❡♥ts ✇✐t❤ r❡❣❛r❞ t♦ ♠❡❛s✉r❡❞ ✇✐❞t❤✳

■t ❜❡❝♦♠❡s ❝❧❡❛r t❤❛t t❤❡ ✇✐❞t❤ ♦❢ ♦❜st❛❝❧❡ ❢r♦♥ts ✐s ❣❡♥❡r❛❧❧② ♦✈❡r❡st✐♠❛t❡❞ ❛t

s♠❛❧❧❡r ❞✐st❛♥❝❡s✳ ❚❤✐s ✐s ❝❛✉s❡❞ ❜② ✐♠❛❣❡ ♣❛t❝❤❡s ♦♥ t❤❡ maxLevel t❤❛t ❝♦♥✲

t❛✐♥ t❤❡ ❜♦r❞❡r ♦❢ ❛♥ ♦❜st❛❝❧❡ ❛♥❞ ❛r❡ s❡❧❡❝t❡❞ ✇✐t❤♦✉t ❢✉rt❤❡r ✐♥s♣❡❝t✐♦♥✳ ❚❤❡

♠❛❣♥✐t✉❞❡ ♦❢ t❤✐s ❡✛❡❝t ❝❛♥ ❜❡ ✐♥✢✉❡♥❝❡❞ ❜② ❝❤♦♦s✐♥❣ ❛ ❞✐✛❡r❡♥t maxLevel

❛♥❞ fixedInspectThreshold✳ ❙♠❛❧❧❡r ❞❡t❡❝t❡❞ ♦❜st❛❝❧❡ ❢r♦♥ts ❛t ❞✐st❛♥❝❡s ♦❢

✹ ♠❡t❡rs ❛♥❞ ✺ ♠❡t❡rs ❛r❡ ❛ r❡s✉❧t ♦❢ t❤❡ ♥❛t✉r❡ ♦❢ t❤❡ ❞✐s♣❛r✐t② ♠❛♣ r❡❣✐♦♥s

❞❡♣✐❝t✐♥❣ t❤❡ ♦❜st❛❝❧❡✳ ❙✐♥❝❡ t❤❡ ❞✐st✐♥❝t ❜♦r❞❡rs ♦❢ t❤❡ ❧❡❢t ❛♥❞ r✐❣❤t ❡❞❣❡s

♦❢ t❤❡ ♦❜st❛❝❧❡s ❛r❡ t❤❡ ♠❛✐♥ s♦✉r❝❡ ♦❢ ✈❛❧✐❞ r❡❣✐♦♥s ♦♥ t❤❡ ❞✐s♣❛r✐t② ♠❛♣✱ ♥♦t

t❤❡ ❛❝t✉❛❧ ♦❜st❛❝❧❡ s✉r❢❛❝❡s✱ ♦♥❧② ♦♥❡ ♦❢ t❤❡s❡ r❡❣✐♦♥s r❡s✉❧t✐♥❣ ❢r♦♠ ❛♥ ❡❞❣❡

♠❛② ❜❡ ❞❡t❡❝t❡❞ ❜② t❤❡ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ❛❧❣♦r✐t❤♠✳ ❚❤✐s ❧❡❛❞s t♦ ❛ ❞❡t❡❝t❡❞

♦❜st❛❝❧❡ ❢r♦♥t t❤❛t ❤❛s r♦✉❣❤❧② ❤❛❧❢ t❤❡ ✇✐❞t❤ ♦❢ t❤❡ ❛❝t✉❛❧ ❢r♦♥t✳

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✺ ❊✈❛❧✉❛t✐♦♥ ❏❛♥♥✐s ■❤r✐❣

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measured obstacle width in % of actual obstacle width

❋✐❣✉r❡ ✶✾✿ ▼❡❛s✉r❡❞ ✇✐❞t❤ ♦❢ ♦❜st❛❝❧❡ ❢r♦♥ts✳ ❚❤❡ ❤✐st♦❣r❛♠s s❤♦✇ r❡s✉❧ts ❢♦r

♦❜st❛❝❧❡s ♣❧❛❝❡❞ ❛t ❞✐st❛♥❝❡s t♦ t❤❡ ❝❛♠❡r❛ ❢r♦♠ ✶ ♠❡t❡r ❛t t❤❡ t♦♣ ✉♣ t♦ ✺ ♠❡t❡rs

❞✐st❛♥❝❡ ❛t t❤❡ ❜♦tt♦♠✳

❚❤❡ ♣r❡✈✐♦✉s ❡①♣❡r✐♠❡♥t ❛❧r❡❛❞② ❝♦✈❡r❡❞ t❤❡ ❛❝❝✉r❛❝② ♦❢ ♠❡❛s✉r❡❞ ❞✐st❛♥❝❡s

❜❡t✇❡❡♥ ♦❜st❛❝❧❡s ❛♥❞ t❤❡ ❝❛r✳ ❋✐❣✉r❡ ✷✵ ❞❡s❝r✐❜❡s t❤❡ ❤♦r✐③♦♥t❛❧ ❧♦❝❛t✐♦♥ ♦❢

❞❡t❡❝t❡❞ ♦❜st❛❝❧❡ ❢r♦♥ts ❝♦♠♣❛r❡❞ t♦ t❤❡ ❛❝t✉❛❧ ❢r♦♥ts✳ ■t s❤♦✇s t❤❡ ♠❡❛♥

❤♦r✐③♦♥t❛❧ ❞✐s♣❧❛❝❡♠❡♥t ❜❡t✇❡❡♥ ❝❡♥t❡rs ♦❢ ❞❡t❡❝t❡❞ ❛♥❞ ❛❝t✉❛❧ ❢r♦♥ts ❛♥❞ t❤❡

r❡❧❛t❡❞ st❛♥❞❛r❞ ❞❡✈✐❛t✐♦♥✳ ❚❤❡ ❞✐s♣❧❛❝❡♠❡♥t ❢♦r s♠❛❧❧❡r ❞✐st❛♥❝❡s ✐s s♠❛❧❧

❡♥♦✉❣❤ t♦ ❛ss✉♠❡❞ t❤❛t ❛ ❞❡t❡❝t❡❞ ♦❜st❛❝❧❡ ❢r♦♥t ❝♦♠♣❧❡t❡❧② ❝♦✈❡rs t❤❡ ❛❝✲

t✉❛❧ ♦❜st❛❝❧❡ ❢r♦♥t✳ ❚❤✐s ❛❧s♦ ❤❡❧♣s t♦ ❝♦♠♣❡♥s❛t❡ ❢♦r ♦✈❡r❡st✐♠❛t❡❞ ✇✐❞t❤ ♦❢

♦❜st❛❝❧❡s✳

♦❜st❛❝❧❡ ❞✐st❛♥❝❡ ✐♥ ♠✶ ✷ ✸ ✹ ✺

♠❡❛♥ ❞✐st❛♥❝❡ ✐♥ ♠ ✵✳✵✸✺ ✵✳✵✶✼ ✵✳✵✶✷ ✲✵✳✵✵✹ ✲✵✳✵✺✸st❛♥❞❛r❞ ❞❡✈✐❛t✐♦♥ ✐♥ ♠ ✵✳✵✷✵ ✵✳✵✷✻ ✵✳✵✸✼ ✵✳✵✺✻ ✵✳✵✾✼

❋✐❣✉r❡ ✷✵✿ ❉✐s♣❧❛❝❡♠❡♥t ❜❡t✇❡❡♥ t❤❡ ❝❡♥t❡r ♦❢ ❞❡t❡❝t❡❞ ♦❜st❛❝❧❡ ❢r♦♥ts ❛♥❞ t❤❡

❝❡♥t❡r ♦❢ t❤❡ ❛rt✐✜❝✐❛❧❧② ❝r❡❛t❡❞ r❡❢❡r❡♥❝❡s✳

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✺ ❊✈❛❧✉❛t✐♦♥ ❏❛♥♥✐s ■❤r✐❣

✺✳✺ ❊①♣❡r✐♠❡♥t ✹✿ ❘✉♥t✐♠❡

❘✉♥t✐♠❡ ✐s ♦♥❡ ♦❢ t❤❡ ♠♦st ✐♠♣♦rt❛♥t ❢❛❝t♦rs ✐♥ t❤❡ ❡✈❛❧✉❛t✐♦♥ ♦❢ t❤❡ ♣r♦♣♦s❡❞

♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ♠❡t❤♦❞✱ s✐♥❝❡ t❤❡ ❛❧❣♦r✐t❤♠ ❤❛s t♦ r✉♥ ✇✐t❤ ❛ ♠❛①✐♠✉♠ ♦❢

✺✵ ♠s ♦♥ t❤❡ ❖❞r♦✐❞✲❳❯ t♦ ❜❡ ❛❜❧❡ t♦ ❡①❡❝✉t❡ ❢♦r ❡✈❡r② ♦♥❡ ♦❢ t❤❡ ✷✵ ❢r❛♠❡s

❞❡❧✐✈❡r❡❞ ❜② t❤❡ ❝❛♠❡r❛ ♣❡r s❡❝♦♥❞✳ ▲♦✇❡r ❢r❛♠❡ r❛t❡s ❛r❡ ✉♥❞❡s✐r❛❜❧❡ ❛s t❤❡②

❝♦✉❧❞ ❦❡❡♣ t❤❡ ❝❛r ❢r♦♠ r❡❛❝❤✐♥❣ ❤✐❣❤❡r s♣❡❡❞s ✇❤✐❧❡ ❛✈♦✐❞✐♥❣ ♦❜st❛❝❧❡s✳

■t ❤❛s t♦ ❜❡ ♠❡♥t✐♦♥❡❞ t❤❛t ♦♥❧② t❤❡ ❡①❡❝✉t✐♦♥ t✐♠❡ ♦❢ t❤❡ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥

♠❡t❤♦❞ ❞❡s❝r✐❜❡❞ s❡❝t✐♦♥ ✹ ✐s t❡st❡❞ ❤❡r❡✳ ❈r❡❛t✐♦♥ ♦❢ ❛❧❧ ✐♥t❡❣r❛❧ ✐♠❛❣❡s

t♦❣❡t❤❡r ❝✉rr❡♥t❧② t❛❦❡s ❛♥ ❛❞❞✐t✐♦♥❛❧ ✷✸ ♠s ♦♥ ❛✈❡r❛❣❡✳ ❇✉t t❤❡ ❝✉rr❡♥t

✐♠♣❧❡♠❡♥t❛t✐♦♥ ❧❡❛✈❡s ❛ ❧♦t ♦❢ r♦♦♠ ❢♦r ♦♣t✐♠✐③✐♥❣ t❤✐s ♣r♦❝❡ss s✐♥❝❡ t❤❡ ❢♦❝✉s

♦❢ t❤✐s ✇♦r❦ ❧✐❡s ♦♥ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥✳ ❚❤❡r❡ ❛r❡ ❡✛♦rts t♦ ♠♦✈❡ ❝r❡❛t✐♦♥ ♦❢

✐♥t❡❣r❛❧ ✐♠❛❣❡s t♦ t❤❡ ●P❯ ❛❧t♦❣❡t❤❡r✳

❆s ❛❧r❡❛❞② ♠❡♥t✐♦♥❡❞ ✐♥ s❡❝t✐♦♥ ✺✳✶✱ maxLevel ❣r❡❛t❧② ✐♥✢✉❡♥❝❡s t❤❡ ❡①❡❝✉✲

t✐♦♥ t✐♠❡ ❢♦r t❤❡ ❛❧❣♦r✐t❤♠✳ ❇✉t ❛s ♣✐①❡❧s ♦♥ ✐♠❛❣❡s ♦♥ ❤✐❣❤❡r ❧❡✈❡❧s ♦❢ t❤❡

✐♠❛❣❡ ♣②r❛♠✐❞s ❛r❡ ♦♥❧② ✐♥s♣❡❝t❡❞ ❢♦r ❡❧❡✈❛t❡❞ r❡❣✐♦♥s✱ r✉♥t✐♠❡ ♦❢ t❤❡ ❛❧❣♦✲

r✐t❤♠ ❛❧s♦ ❞❡♣❡♥❞s ♦♥ t❤❡ ♥✉♠❜❡r ♦❢ ♦❜st❛❝❧❡s ✐♥ ❢r♦♥t ♦❢ t❤❡ ❝❛♠❡r❛✳ ❚♦ t❡st

t❤✐s ✵ t♦ ✹ ♦❜st❛❝❧❡s ✇❤❡r❡ ♣❧❛❝❡❞ ✐♥ ❢r♦♥t ♦❢ t❤❡ ❝❛♠❡r❛ ❛t ❛ ❞✐st❛♥❝❡ ♦❢ ✷

♠❡t❡rs✳ ❙✐t✉❛t✐♦♥s ✇✐t❤ ♠♦r❡ t❤❛♥ ✹ ♦❜st❛❝❧❡s ✐♥ ❢r♦♥t ♦❢ t❤❡ ❝❛r ✇✐❧❧ r❛r❡❧②

❜❡ ❡♥❝♦✉♥t❡r❡❞ ✐♥ t❤❡ ❈❛r♦❧♦✲❈✉♣✳ ❆ r♦✉❣❤❧② ❧✐♥❡❛r r❡❧❛t✐♦♥ ❜❡t✇❡❡♥ ♥✉♠❜❡r

♦❢ ♦❜st❛❝❧❡s ❛♥❞ ❡①❡❝✉t✐♦♥ t✐♠❡ ❝❛♥ ❜❡ ❡①♣❡❝t❡❞✱ ❛s t❤❡ ♥✉♠❜❡r ♦❢ r❡❣✐♦♥s ♦♥

t❤❡ ❞✐s♣❛r✐t② ♠❛♣ t❤❛t ❤❛✈❡ t♦ ❜❡ ✐♥s♣❡❝t❡❞ ✐♥❝r❡❛s❡s ❧✐♥❡❛r❧② ❢♦r ♦❜st❛❝❧❡s ♦❢

t❤❡ s❛♠❡ s✐③❡✳

♥✉♠❜❡r ♦❢ ♦❜st❛❝❧❡s✵ ✶ ✷ ✸ ✹

♠❡❛♥ r✉♥t✐♠❡ ✐♥ ♠s ✹✳✸✸✹ ✺✳✶✽✵ ✺✳✹✵✸ ✻✳✹✺✻ ✻✳✼✸✺st❛♥❞❛r❞ ❞❡✈✐❛t✐♦♥ ✐♥ ♠s ✵✳✾✻✾ ✵✳✾✼✾ ✶✳✵✸✾ ✶✳✵✼✶ ✶✳✵✽✹

❋✐❣✉r❡ ✷✶✿ ▼❡❛s✉r❡❞ r✉♥t✐♠❡ ❞❡♣❡♥❞✐♥❣ ♦♥ t❤❡ ♥✉♠❜❡r ♦❢ ♦❜st❛❝❧❡s✳ ❚❤❡

♠❡❛s✉r❡♠❡♥ts ✇❤❡r❡ t❛❦❡♥ ♦♥ t❤❡ ❖❞r♦✐❞✲❳❯ ❝✉rr❡♥t❧② ✉s❡❞ ✐♥ ❇❛❦❡r✳

❋✐❣✉r❡ ✷✶ s❤♦✇s t❤❡ ♠❡❛s✉r❡❞ ♠❡❛♥ r✉♥t✐♠❡ ❛♥❞ t❤❡ r❡❧❛t❡❞ st❛♥❞❛r❞ ❞❡✈✐✲

❛t✐♦♥ ❢♦r ❡❛❝❤ ♥✉♠❜❡r ♦❢ ♦❜st❛❝❧❡s✳ ■t ✉♥❞❡r❧✐♥❡s t❤❡ ♣r❡✈✐♦✉s ❛ss✉♠♣t✐♦♥ ♦❢

❧✐♥❡❛r❧② ✐♥❝r❡❛s✐♥❣ r✉♥t✐♠❡ ❢♦r ✐♥❝r❡❛s✐♥❣ ♦❜st❛❝❧❡ ♥✉♠❜❡rs✳ ▼♦r❡ ✐♠♣♦rt❛♥t✱

♦✈❡r❛❧❧ r✉♥t✐♠❡ ✐s ❧♦✇ ❡♥♦✉❣❤ t♦ ❛❧❧♦✇ ❡①❡❝✉t✐♦♥ ♦❢ t❤❡ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ❛❧❣♦✲

r✐t❤♠ ❛t ✷✵ ❍③✱ ❡✈❡♥ ✇✐t❤ t❤❡ ❛❞❞✐t✐♦♥❛❧ ✷✸ ♠s ♦❢ ❡①❡❝✉t✐♦♥ t✐♠❡ ❢♦r ❝r❡❛t✐♥❣

t❤❡ ✐♥t❡❣r❛❧ ✐♠❛❣❡s✳

✸✹

Page 40: Obstacle detection for an autonomous model car …...a stereo vision based real-time obstacle detection system for an autonomous model car on the scale of 1:10 built for the annual

✻ ❈♦♥❝❧✉s✐♦♥ ❛♥❞ ❢✉t✉r❡ ✇♦r❦ ❏❛♥♥✐s ■❤r✐❣

✻ ❈♦♥❝❧✉s✐♦♥ ❛♥❞ ❢✉t✉r❡ ✇♦r❦

❆s st❛t❡❞ ✐♥ t❤❡ ♣r♦❜❧❡♠ ❞❡s❝r✐♣t✐♦♥✱ t❤✐s ✇♦r❦ ✐s ♠❡❛♥t t♦ ❛❞❞ ♥❡✇ ♦❜st❛❝❧❡

❞❡t❡❝t✐♦♥ ❝❛♣❛❜✐❧✐t✐❡s t♦ t❤❡ ❡①✐st✐♥❣ ♣❧❛t❢♦r♠ ❛s ❛ ❜❛s✐s ❢♦r ❧❛t❡r ♦❜st❛❝❧❡

❛✈♦✐❞❛♥❝❡ ❜❡❤❛✈✐♦r✳ ❚❤❡ ✜rst t❛s❦ ✇❛s t♦ ❡①t❡♥❞ t❤❡ ❡①✐st✐♥❣ ❤❛r❞✇❛r❡ ✇✐t❤

❛ s❡♥s♦r ❝❛♣❛❜❧❡ ♦❢ ♣❡r❝❡✐✈✐♥❣ ❞❡♣t❤✳ ❚❤❡ r❡❝❡✐✈❡❞ s❡♥s♦r ❞❛t❛ s❤♦✉❧❞ ❛❧❧♦✇

♥♦t ♦♥❧② ❞❡t❡❝t✐♦♥ ♦❢ ♦❜st❛❝❧❡s ❜✉t ❛❧s♦ ❛♥ ❡st✐♠❛t✐♦♥ ♦❢ t❤❡✐r ♣♦s✐t✐♦♥✳ ❚❤✐s

✇❛s s✉❝❝❡ss❢✉❧❧② ❞♦♥❡ ❜② ✐♥t❡❣r❛t✐♥❣ ❱✐s❑❖❙✲❙♠❛rt❈❛♠ ✇✐t❤ t❤❡ ❢r❛♠❡✇♦r❦

❛s ♣r❡s❡♥t❡❞ ✐♥ s❡❝t✐♦♥ ✸✳✷✳

❚❤❡ s❡❝♦♥❞ st❡♣ ✇❛s t♦ ♣r♦♣♦s❡ ❛♥❞ ✐♠♣❧❡♠❡♥t ❛♥ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ♠❡t❤♦❞

t❤❛t ✇♦✉❧❞ ✇♦r❦ ✐♥ t❤❡ r❡❞✉❝❡❞ ❡♥✈✐r♦♥♠❡♥t ❞❡✜♥❡❞ ❜② t❤❡ ❈❛r♦❧♦✲❈✉♣ r✉❧❡s✳

❚❤❡ ❡✈❛❧✉❛t✐♦♥ ♦❢ t❤❡ ♣r❡s❡♥t❡❞ ❛♣♣r♦❛❝❤ ✐♥ s❡❝t✐♦♥ ✺ s❤♦✇s t❤❛t ✐t r❡❧✐❛❜❧②

❞❡t❡❝ts ♦❜st❛❝❧❡s✳ ❚❤❡ st❡r❡♦ ❝❛♠❡r❛ ❝♦♠❜✐♥❡❞ ✇✐t❤ ✐♠♣❧❡♠❡♥t❡❞ ♦❜st❛❝❧❡

❞❡t❡❝t✐♦♥ ♠❡t❤♦❞ ❛❧❧♦✇s ❛♥ ❛♣♣r♦①✐♠❛t✐♦♥ ♦❢ ♦❜st❛❝❧❡ ❧♦❝❛t✐♦♥s ✇✐t❤ ❤✐❣❤ ❛❝✲

❝✉r❛❝②✳ ❆s ♣r❡✈✐♦✉s❧② st❛t❡❞✱ t❤❡ s♦❢t✇❛r❡ ❤❛s t♦ r✉♥ ✇✐t❤ ✷✵❍③ ❛♥❞ ❧✐♠✐t❡❞

r❡s♦✉r❝❡s ♣r♦✈✐❞❡❞ ❜② ♣❧❛t❢♦r♠✬s ❝❡♥tr❛❧ ♣r♦❝❡ss♦r ✐♥ ♦r❞❡r t♦ ♣❡r❢♦r♠ r❡❛❧✲t✐♠❡

♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥✳ ❚❤❡ ❡①♣❡r✐♠❡♥t❛❧ r❡s✉❧ts ♣r❡s❡♥t❡❞ ✐♥ s❡❝t✐♦♥ ✺✳✺ s❤♦✇❡❞

t❤❛t t❤✐s ✇❛s ❛❝❤✐❡✈❡❞✳

■♥ ❝♦♥❝❧✉s✐♦♥✱ ❛❧❧ t❤❡ r❡q✉✐r❡♠❡♥ts ❧✐st❡❞ ✐♥ s❡❝t✐♦♥ ✶✳✸ ❤❛✈❡ ❜❡❡♥ ❢✉❧✜❧❧❡❞ ❝♦♠✲

♣❧❡t❡❧②✳ ❚❤❡ s♦❧✉t✐♦♥ r❡♣r❡s❡♥ts ❛♥ ❡①❝❡❧❧❡♥t ❜❛s✐s ❢♦r ❢✉rt❤❡r ✇♦r❦ ♦♥ ♦❜st❛❝❧❡

❛✈♦✐❞❛♥❝❡ ❜❡❤❛✈✐♦r✳ ❚❤✐s ♥❡①t st❡♣ ✇♦✉❧❞ ❛❧❧♦✇ t❤❡ t❡❛♠ t♦ t❛❦❡ ♣❛rt ✐♥

t❤❡ ❝❤❛❧❧❡♥❣❡ ❉r✐✈✐♥❣ ❲✐t❤ ❖❜st❛❝❧❡s ✐♥ t❤❡ ❈❛r♦❧♦✲❈✉♣ ❝♦♥t❡st✳ ❚❤❡ ✐♠♣❧❡✲

♠❡♥t❡❞ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ s②st❡♠ ❝♦♥tr✐❜✉t❡s ❣r❡❛t❧② t♦ t❤❡ ❝♦♠♣❡t✐t✐✈❡♥❡ss

♦❢ t❤❡ t❡❛♠✬s ♣❧❛t❢♦r♠✳

❆t t❤❡ s❛♠❡ t✐♠❡✱ t❤❡ s♦❧✉t✐♦♥ ❧❡❛✈❡s s♣❛❝❡ ❢♦r ❢✉rt❤❡r ✐♠♣r♦✈❡♠❡♥ts✳ ❊①♣❡r✲

✐♠❡♥ts ❞✐s❝✉ss❡❞ ✐♥ ✺✳✷ ❛♥❞ ✺✳✸ s❤♦✇❡❞ t❤❛t t❤❡ ❞❡✈❡❧♦♣❡❞ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥

♠❡t❤♦❞ ✇♦✉❧❞ ❜❡♥❡✜t ♥♦t❛❜❧② ❢r♦♠ ❛ ♠♦r❡ ❝♦♠♣❧❡① ♦❜st❛❝❧❡ ♠♦❞❡❧ t❤❛t tr❛❝❦s

♦❜st❛❝❧❡s ♦✈❡r ♠✉❧t✐♣❧❡ ❢r❛♠❡s ❛♥❞ ✜❧t❡rs ♣♦s✐t✐♦♥ ❛♥❞ ❞✐st❛♥❝❡ t♦ ❣❡t ♠♦r❡ ❛❝✲

❝✉r❛t❡ ❡st✐♠❛t❡s✳ ❋✉rt❤❡r✱ t❤❡ ❛❧❣♦r✐t❤♠✬s st❡♣ ♦❢ ❛♣♣r♦①✐♠❛t✐♥❣ t❤❡ s✉r❢❛❝❡

♦❢ ♦❜st❛❝❧❡s ♠✐❣❤t ❜❡ ❡♥❤❛♥❝❡❞ t♦ ❝♦♥str✉❝t t❤❡ t❤r❡❡✲❞✐♠❡♥s✐♦♥❛❧ r❡♣r❡s❡♥t❛✲

t✐♦♥s ♦❢ ♦❜st❛❝❧❡s✳ ❚❤✐s ❝♦✉❧❞ ❜❡ ❞♦♥❡ ❜② ❝❛❧❝✉❧❛t✐♥❣ t❤❡ ♥♦r♠❛❧s ❢♦r s❡❧❡❝t❡❞

♣✐①❡❧s ♦♥ t❤❡ ✐♠❛❣❡ ♣②r❛♠✐❞s ❞❡r✐✈❡❞ ❢r♦♠ t❤❡ ❞✐st❛♥❝❡ ♠❛♣✳ ❚❤❡ ✇♦r❦ ♣r❡✲

s❡♥t❡❞ ✐♥ ❬✸❪ ❝❛♥ s❡r✈❡ ❛s ❛ ✉s❡❢✉❧ ❜❛s✐s ❢♦r t❤✐s t❛s❦✳ ❚❤❡ ❝r❡❛t✐♦♥ ♦❢ ✐♥t❡❣r❛❧

✐♠❛❣❡s ❝❛♥ ❜❡ ♦♣t✐♠✐③❡❞ ♦r ♠♦✈❡❞ t♦ t❤❡ ❖❞r♦✐❞s ●P❯✱ ❞r❛st✐❝❛❧❧② ✐♥❝r❡❛s✐♥❣

♦✈❡r❛❧❧ ♣❡r❢♦r♠❛♥❝❡✳

✸✺

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✻ ❈♦♥❝❧✉s✐♦♥ ❛♥❞ ❢✉t✉r❡ ✇♦r❦ ❏❛♥♥✐s ■❤r✐❣

❙✐♥❝❡ ♦♥❡ ♦❢ t❤❡ ♠❛✐♥ ❞✐✣❝✉❧t✐❡s ♦❢ ❛ st❡r❡♦ ❜❛s❡❞ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ❛♣♣r♦❛❝❤

✐♥ t❤❡ ❈❛r♦❧♦✲❈✉♣ ❡♥✈✐r♦♥♠❡♥t ✐s t❤❡ ❧♦✇ ❛♠♦✉♥t ♦❢ ❢❡❛t✉r❡s ❢♦✉♥❞ ♦♥ ✐♠❛❣❡s✱

❡①♣❡r✐♠❡♥ts ❞♦♥❡ ✇✐t❤ ❛♥ ✐♥❢r❛r❡❞ ♣r♦❥❡❝t♦r✱ ❛s ✉s❡❞ ✐♥ t❤❡ ❑✐♥❡❝t✱ ♣r♦♠✐s❡s

❣r❡❛t r❡s✉❧ts✳ ▼♦✉♥t✐♥❣ ✐t ♥❡①t t♦ t❤❡ st❡r❡♦ ❝❛♠❡r❛ ✇♦✉❧❞ ♣r♦❥❡❝t ✐♥❢r❛r❡❞

♥♦✐s❡ ♦♥ t❤❡ ♣❧❛✐♥ ✇❤✐t❡ s✉r❢❛❝❡s ♦❢ ♦❜st❛❝❧❡s ❛♥❞ r❡s✉❧t ✐♥ ❛ ❞❡♥s❡r ❞✐s♣❛r✐t②

♠❛♣ ♦❢ t❤❡s❡ r❡❣✐♦♥s✳

❆❧❧ ♦❢ t❤❡s❡ ♣r♦♠✐s✐♥❣ ❛♣♣r♦❛❝❤❡s t♦ ❢✉rt❤❡r ✐♠♣r♦✈❡ t❤❡ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥

❝❛♣❛❜✐❧✐t✐❡s ♦❢ t❤❡ ❛✉t♦♥♦♠♦✉s ♠♦❞❡❧ ❝❛r ✇✐❧❧ ❜❡ ♣✉rs✉❡❞ ❜② t❤❡ ❇❡r❧✐♥ ❯♥✐t❡❞

❘❛❝✐♥❣ ❚❡❛♠ t♦ str❡♥❣t❤❡♥ ♦✉r ❝♦♠♣❡t✐t✐✈❡ ♣♦s✐t✐♦♥ ✐♥ t❤❡ ✉♣❝♦♠✐♥❣ ❝♦♠♣❡✲

t✐t✐♦♥s✳

✸✻

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❘❡❢❡r❡♥❝❡s

❬✶❪ ❆✉t♦♥♦♠❡s ❋❛❤r③❡✉❣ ✒❈❛r♦❧✐♥❡✏ ❜❡st❡❤t ◗✉❛❧✐❢②✐♥❣ ♠✐t ❇r❛✈♦✉r✳

❯❘▲✿ ❤tt♣s✿✴✴✇✇✇✳t✉✲❜r❛✉♥s❝❤✇❡✐❣✳❞❡✴♣r❡ss❡✴♠❡❞✐❡♥✴

♣r❡ss❡✐♥❢♦r♠❛t✐♦♥❡♥❄②❡❛r❂✷✵✵✼✫♣✐♥r❂✶✸✼✳

❬✷❪ ❉❆❘P❆ ❯r❜❛♥ ❈❤❛❧❧❡♥❣❡✳ ❯❘▲✿ ❤tt♣✿✴✴❛r❝❤✐✈❡✳❞❛r♣❛✳♠✐❧✴

❣r❛♥❞❝❤❛❧❧❡♥❣❡✴✳

❬✸❪ ■♥ ❚❤♦♠❛s ❘ö❢❡r✱ ◆✳ ▼✐❝❤❛❡❧ ▼❛②❡r✱ ❏❡s✉s ❙❛✈❛❣❡✱ ❛♥❞ ❯❧✉❝ ❙❛r❛♥❧✙✱

❡❞✐t♦rs✱ ❘♦❜♦❈✉♣ ✷✵✶✶✿ ❘♦❜♦t ❙♦❝❝❡r ❲♦r❧❞ ❈✉♣ ❳❱✱ ✈♦❧✉♠❡ ✼✹✶✻ ♦❢

▲❡❝t✉r❡ ◆♦t❡s ✐♥ ❈♦♠♣✉t❡r ❙❝✐❡♥❝❡✳ ✷✵✶✷✳

❬✹❪ ❈❛r♦❧♦✲❈✉♣ ❘❡❣❡❧✇❡r❦ ✷✵✶✺✳ ❚❡❝❤♥✐s❝❤❡ ❯♥✐✈❡rs✐ät ❇r❛✉♥s❝❤✇❡✐❣✱

✵✸✳ ❏✉♥✐ ✷✵✶✹✳ ❯❘▲✿ ❤tt♣s✿✴✴✇✐❦✐✳✐❢r✳✐♥❣✳t✉✲❜s✳❞❡✴❝❛r♦❧♦❝✉♣✴

s②st❡♠✴❢✐❧❡s✴❍❛✉♣t✇❡tt❜❡✇❡r❜✷✵✶✺✳♣❞❢✳

❬✺❪ ❊✳ ❍✳ ❆❞❡❧s♦♥✱ ❈✳ ❍✳ ❆♥❞❡rs♦♥✱ ❏✳ ❘✳ ❇❡r❣❡♥✱ P✳ ❏✳ ❇✉rt✱ ❛♥❞ ❏✳ ▼✳ ❖❣❞❡♥✳

P②r❛♠✐❞ ♠❡t❤♦❞s ✐♥ ✐♠❛❣❡ ♣r♦❝❡ss✐♥❣✳ ❘❈❆ ❊♥❣✐♥❡❡r ✷✾✱ ✶✾✽✹✳

❬✻❪ ■❧♦♥❛ ❇✳ ❇❧❛♥❝❦✳ ❇❛❤♥♣❧❛♥✉♥❣ ❡✐♥❡s ❛✉t♦♥♦♠❡♥ ❋❛❤r③❡✉❣s ❛♠ st❛t✐♦♥är❡♥

❍✐♥❞❡r♥✐s✳ ❍♦❝❤s❝❤✉❧❡ ❢ür ❛♥❣❡✇❛♥❞t❡ ❲✐ss❡♥s❝❤❛❢t❡♥ ❍❛♠❜✉r❣✱ ✷✵✵✾✳

❬✼❪ ▲✳ ❇♦✱ ❳✳ ❘❡♥✱ ❛♥❞ ❉✳ ❋♦①✳ ❯♥s✉♣❡r✈✐s❡❞ ❋❡❛t✉r❡ ▲❡❛r♥✐♥❣ ❢♦r ❘●❇✲❉

❇❛s❡❞ ❖❜❥❡❝t ❘❡❝♦❣♥✐t✐♦♥✳ ■♥ ■❙❊❘✱ ❏✉♥❡ ✷✵✶✷✳

❬✽❪ ❏❛♥ ❋r❡❞❡r✐❦ ❇♦❧❞t ❛♥❞ ❙❡✈❡r✐♥ ❏✉♥❦❡r✳ ❊✈❛❧✉❛t✐♦♥ ✈♦♥ ▼❡t❤♦❞❡♥ ③✉r

❯♠❢❡❧❞❡r❦❡♥♥✉♥❣ ♠✐t ❍✐❧❢❡ ♦♠♥✐❞✐r❡❦t✐♦♥❛❧❡r ❑❛♠❡r❛s ❛♠ ❇❡✐s♣✐❡❧ ❡✐♥❡s

▼♦❞❡❧❧❢❛❤r③❡✉❣s✳ ❋r❡✐❡ ❯♥✐✈❡rs✐tät ❇❡r❧✐♥✱ ■♥st✐t✉t ❢ür ■♥❢♦r♠❛t✐❦✱ ✷✵✶✷✳

❬✾❪ ●❛r② ❘♦st ❇r❛❞s❦✐ ❛♥❞ ❆❞r✐❛♥ ❑❛❡❤❧❡r✳ ▲❡❛r♥✐♥❣ ❖♣❡♥❝✈✱ ✶st ❊❞✐t✐♦♥✳

❖✬❘❡✐❧❧② ▼❡❞✐❛✱ ■♥❝✳✱ ✜rst ❡❞✐t✐♦♥✱ ✷✵✵✽✳

❬✶✵❪ ❇✳ ❈②❣❛♥❡❦✳ ❆♥ ■♥tr♦❞✉❝t✐♦♥ t♦ ✸❉ ❈♦♠♣✉t❡r ❱✐s✐♦♥ ❚❡❝❤♥✐q✉❡s ❛♥❞

❆❧❣♦r✐t❤♠s✳ ❏♦❤♥ ❲✐❧❡② ✫ ❙♦♥s✱ ✷✵✵✼✳

❬✶✶❪ ❲❛❧❞❡♠❛r ❍❡❝❦✳ ❍✐♥❞❡r♥✐s✲ ✉♥❞ ❑r❡✉③✉♥❣s❡r❦❡♥♥✉♥❣ ❛✉❢ ❛✉t♦♥♦♠❡♥

❋❛❤r③❡✉❣❡♥ ❞✉r❝❤ ❑❛♠❡r❛ ✉♥❞ ■♥❢r❛r♦ts❡♥s♦r✐❦✳ ❍♦❝❤s❝❤✉❧❡ ❢ür ❛♥❣❡✲

✇❛♥❞t❡ ❲✐ss❡♥s❝❤❛❢t❡♥ ❍❛♠❜✉r❣✱ ✷✵✶✸✳

❬✶✷❪ ❘❛♣❤❛❡❧ ▲❛❜❛②r❛❞❡ ❛♥❞ ❉✐❞✐❡r ❆✉❜❡rt✳ ❘❡❛❧ t✐♠❡ ♦❜st❛❝❧❡ ❞❡t❡❝t✐♦♥ ✐♥

st❡r❡♦✈✐s✐♦♥ ♦♥ ♥♦♥ ✢❛t r♦❛❞ ❣❡♦♠❡tr② t❤r♦✉❣❤ ✈✲❞✐s♣❛r✐t② r❡♣r❡s❡♥t❛t✐♦♥✳

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♣❛❣❡s ✻✹✻✕✻✺✶ ♦❢✿ Pr♦❝s✳ ❚❡❝❤♥✐❝❛❧ r❡♣♦rt✱ Pr♦❝✳ ❙P■❊ ✷✸✽✳ ✼✶ ✶✸✻ ✈❡rs✐♦♥

✶ ✲ ✾ ❙❡♣ ✷✵✶✶ ▲❡●✉✐❧❧♦✉①✱ ✷✵✵✷✳

❬✶✸❪ ▼❛r❦✉s ▼❛✉r❡r✳ ❊❧❡❦tr♦♥✐s❝❤❡ ❋❛❤r③❡✉❣s②st❡♠❡ ✷✵✶✷✳ ❏❛❤r❡s❜❡r✐❝❤t✿

❆❦❛❞❡♠✐s❝❤❡s ❏❛❤r ✷✵✶✶✴✷✵✶✷✳ ❇❡r♥❞ ▲✐❝❤t❡✱ ❚❡❝❤♥✐s❝❤❡ ❯♥✐✈❡rs✐tät

❇r❛✉♥s❝❤✇❡✐❣✱ ✷✵✶✷✳

❬✶✹❪ ❉r✳ ❏❛✈✐❡r ❘♦❥♦✱ ❉r✳ ❘❛ú❧ ❘♦❥❛s✱ ❡t ❛❧✳ ❙♣✐r✐t ♦❢ ❇❡r❧✐♥✿ ❆♥ ❆✉t♦♥♦♠♦✉s

❈❛r ❢♦r t❤❡ ❉❆❘P❆ ❯r❜❛♥ ❈❤❛❧❧❡♥❣❡✳ ❍❛r❞✇❛r❡ ❛♥❞ ❙♦❢t✇❛r❡ ❆r❝❤✐t❡❝✲

t✉r❡✳ ✷✵✵✼✳

❬✶✺❪ ❙❡❜❛st✐❛♥ ❚❤r✉♥✱ ❲♦❧❢r❛♠ ❇✉r❣❛r❞✱ ❛♥❞ ❉✐❡t❡r ❋♦①✳ Pr♦❜❛❜✐❧✐st✐❝

❘♦❜♦t✐❝s✳ ❚❤❡ ▼■❚ Pr❡ss✱ ✷✵✵✺✳

❬✶✻❪ P❛✉❧ ❱✐♦❧❛ ❛♥❞ ▼✐❝❤❛❡❧ ❏✳ ❏♦♥❡s✳ ❘♦❜✉st ❘❡❛❧✲❚✐♠❡ ❋❛❝❡ ❉❡t❡❝t✐♦♥✳ ■♥t✳

❏✳ ❈♦♠♣✉t✳ ❱✐s✐♦♥✱ ✺✼✭✷✮✿✶✸✼✕✶✺✹✱ ▼❛② ✷✵✵✹✳

❬✶✼❪ ❏ör♥ ▼❛rt❡♥ ❲✐❧❧❡ ❡t ❛❧✳ ❉❡r ❙t❛❞t♣✐❧♦t✳ ❆✉t♦♥♦♠❡s ❋❛❤r❡♥ ❛✉❢ ❞❡♠

❇r❛✉♥s❝❤✇❡✐❣❡r ❙t❛❞tr✐♥❣✳ ❚❡❝❤♥✐s❝❤❡ ❯♥✐✈❡rs✐tät ❇r❛✉♥s❝❤✇❡✐❣✱ ✷✵✶✶✳