1 / 11

« Structure from motion » algorithms for the CYCAB robot

« Structure from motion » algorithms for the CYCAB robot. Guillaume CERNIER ENSIMAG - 2nd year internship 19th June - 15th September 2006. INRIA presentation. Well-known french research centre in : Computer science Control theory Applied mathematics

hea
Télécharger la présentation

« Structure from motion » algorithms for the CYCAB robot

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. « Structure from motion » algorithms for the CYCAB robot Guillaume CERNIER ENSIMAG - 2nd year internship 19th June - 15th September 2006

  2. INRIA presentation • Well-known french research centre in : • Computer science • Control theory • Applied mathematics • 6 research centres (Lorraine, Rennes, Rhône-Alpes, Rocquencourt, Sophia-Antipolis, Futurs) • Partner of the new research centre of Microsoft at Orsay • INRIA Rhône-Alpes unit : • 26 research teams among 8 associated with foreign laboratories • Near 500 people (engineers, researches, PhD students, interns, …) • Local partners : IMAG, UJF, INPG, CNRS, … • Member of 10 european research networks • 271 contracts among 53 with industry and 26 european • 14 start-ups created since 1998 (more than 560 jobs created) Guillaume CERNIER« Structure from motion » algorithms for the CYCAB robot

  3. e-Motion team presentation • “GEometry and Probability for MOtion and AcTION” • Belongs to the GRAVIR lab (INRIA, CNRS, UJF, INPG) • Goals : • Developing algorithmic models and methods allowing to build artificial systems • With capacities of perception, decision, and action • Operating in open and dynamic environments • Start-ups : Itmi (1982), Getris Images (1985), Aleph Technologies (1989), Aleph Med (1992), Probayes (2003). • Industrial collaborations : Robotsoft, Renault, PSA, AW Europe (linked to Toyota), XL-Studio, Aesculap, Teamlog, Kelkoo. Guillaume CERNIER« Structure from motion » algorithms for the CYCAB robot

  4. CYCAB presentation • Large R&D program between INRIA & INRETS • Autonomous vehicle intended for urban areas • Automatic taxi computer-guided • Can be adapted for blind and/or handicapped people • Autonomous + urban areas => avoiding obstacles • Before my internship : avoidance realized by a laser telemeter • Internship goal : use a video camera to estimate the structure of the whole scene in front of the vehicle • Called “structure from motion” Guillaume CERNIER« Structure from motion » algorithms for the CYCAB robot

  5. 3D estimation of the structure Internship goals Videos, sequence of pictures • Constraints : • Software development : C/C++ • Real-time processing • Integration to the whole platform embedded in the Cycab (plug-in format) Helps : • Use of an open-source 3D vision library : “OpenCV” Guillaume CERNIER« Structure from motion » algorithms for the CYCAB robot

  6. “Structure from motion” (1/3) • The problem : only one camera => unknown motion between 2 snapshots • So, structure from motion is a 2-step process : • Optical flow (vector field) computation between 2 pictures • Thanks to this optical flow, computing : • First, the motion of the camera between the 2 pictures • Finally, the 3D structure of the scene Guillaume CERNIER« Structure from motion » algorithms for the CYCAB robot

  7. Optical flow computation (2/3) • SPARSE Vector field • To lighten computation • Vectors tracking real points in the scene • How choose the points to track ? • GoodFeaturesToTrack algorithm • Exists in OpenCV library • Computation of the optical flow : • Pyramidal algorithms • Establishing correspondence between points of the 2 pictures • Eliminate “outliers” • Let to know the “fundamental matrix” Guillaume CERNIER« Structure from motion » algorithms for the CYCAB robot

  8. 3D structure computation (3/3) • 2 steps : • Find the motion between the 2 pictures : • Thanks to fundamental & intrinsic matrixes • Find the rotation and translation resulting • Here, we know the position of the camera at the 2 snapshots • Computes the 3D point for each point pair (q1,q2) in the 2 pictures : • Triangulation methods • Least-square methods (retained) • Depends of the projection matrixes P1 & P2 • Pi = KRi( I3x3 | -ti ) (4x3 matrixes) Guillaume CERNIER« Structure from motion » algorithms for the CYCAB robot

  9. Other development • Camera Calibration GUI Guillaume CERNIER« Structure from motion » algorithms for the CYCAB robot

  10. Difficulties and successes • 3D vision library OpenCV contains some bugs … • Tutors absence … • Very interesting research field ! • Reach the internship goals 2 weeks before the planned date • Research article writing for a robotics conf (ICRA 07) • Learning a GUI API (Gtk+) Guillaume CERNIER« Structure from motion » algorithms for the CYCAB robot

  11. Team life • Different culture people (Italian, Brazilian, Asiatic, …) • Summer at INRIA is … Guillaume CERNIER« Structure from motion » algorithms for the CYCAB robot

More Related