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Fingertip Placement Planning for Unknown Object GraspingNatchanon WongwilaiAdviser: Nattee Niparnan, Ph.D.M.Eng.

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Outline• Introduction• How to grasp?, Why failed to grasp?, Goal

• Related Works• Vision-based grasping, Manipulation under uncertainty

• Our Problem• Challenge, Proposed method

• Etc.• Scopes, Work plan

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Robotic Grasping

[http://spectrum.ieee.org/robotics/robotics-software/slideshow-born-bionic/0]

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Modelµ = 0.53

W = 39 g

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How to grasp?

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Unknown object grasping• 2D [Borst el at.,00; Chinellato el at.,05; Calli el

at.,11; ...]• 3D [Miller el at.,03; Goldfeder el at.,07; Hubner el

at.,08; ...]• 2.5D [Richtsfeld el at.,08; ...]• Others [Saxena el at.,08; ...]

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Grasping in Real World• (Video)

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Why failed to grasp?“The most common failure mode I've seen is that the closing fingers bump the object so that the fingers don't touch the intended contact points. Then the fingers knock the object completely out of the grasp. I think the causes are localization errors from the perception system and asking the robot to carry out an inherently dynamic task that was planned with static analysis tools.”

Jeff TrinkleGRSSP Workshop 2010

“The most common failure mode I've seen is that the closing fingers bump the object so that the fingers don't touch the intended contact points. Then the fingers knock the object completely out of the grasp. I think the causes are localization errors from the perception system and asking the robot to carry out an inherently dynamic task that was planned with static analysis tools.”

Jeff TrinkleGRSSP Workshop 2010

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Why failed to grasp?• Contact position error• Theory vs. Practical

• Cause of error• Sensor• Control• Computation

Uncertainty

[http://www.cs.columbia.edu/~cmatei/]

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Goal• Accuracy of fingertip placement• Planning• Using camera

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SensorSensor Price Accuracy Data typeTactile sensor Expensive High Force arrayLaser range finder

Expensive High Range

Camera Vary Moderate Image

Tactile sensor[Bekiroglu el at., 11]

Laser range finder Camera

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Related works• Vision-based grasping• Stereo camera• Eye-in-hand camera

• Manipulation under uncertainty• Independent contact region• Visual servoing• Reactive grasping• Probabilistic model

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Vision-based grasping• Stereo vision based grasping• [Popovic et al.,11; Gratal el at., 12]

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Vision-based grasping• Eye-in-hand camera• [Walck el at., 10; Lippiello el at., 11; Calli el at., 11]

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• (Video)

Eye-in-hand grasping

15Manipulation under uncertainty• Independent contact region• [Nilwatchararang et al., 08; Roa et al.,09]

16Manipulation under uncertainty• Visual servoing• [Gratal el at., 12; Calli el at., 11]

17Manipulation under uncertainty• Reactive Grasping• [Teichmann et al.,94; Hsiao et al.,09; Hsiao et al.,10]

18Manipulation under uncertainty• Probabilistic model• [Laaksonen et al.,11; Dogar et al.,11; Platt et al.,11]

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Our Problem• Propose online planning method for

accurate fingertip placement under uncertainty using eye-in-hand camera

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Challenge• ACCURACY!!!

• Insufficient information• Bearing-only data• Unknown object model and properties• Don’t have any initial information• Close-up view with featureless image

• Kinematic constraint• Unreachable position• Object out of view

• Uncertainty• Unpredictable noise

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Proposed method

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How to grasp? (revisited)Modeling

Grasp planning

Localization

Grasping

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Our method

Grasping

Loca

lizat

ion

Mod

elin

gGr

asp

plan

ning

24Simultaneous Localization And Mapping (SLAM)• Robot build up a map and localize itself

simultaneously while traversing in an unknown environment

[Paul Newman, 06]

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Localization & Modeling• Robot location Hand(Fingertips)

location

• Environment map Object model

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Probabilistic map

http://www.biorobotics.org/projects/tslam/experiments/slam1experiment.html

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SLAM algorithm• Probabilistic SLAM [Smith and Cheeseman, 86]• The probability distribution of robot state and landmark locations

• The observation model

• The motion model

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SLAM algorithm• SLAM recursive algorithm• Time-update

•Measurement Update

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Observation model• Feature detection• Point features, Line features

• Feature association• How features associate with landmarks

• Feature measurements• Observation model

[http://www.sciencedirect.com/science/article/pii/S0377042711002834]

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Map representation• How to represent a map (object model)

from available features

[http://www.deskeng.com/articles/aaayex.htm]

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Planning• Exploration• How to explore for object modeling

• Strategy• Close-up strategy• Out of view strategy

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Evaluation• Fingertips placement evaluation• Using ground truth data• Contact position marking

• Modeling evaluation• Using ground truth data from structural environment• Database• Kinect

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Scopes• Develop online planning method for

accurate fingertip placement using eye-in-hand camera

• Not develop algorithm to find grasping points

• No clutter in work space• Simple & Textured object

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Work Plan• Study the works in the related fields• Develop algorithms• Test the system• Evaluate a result• Prepare and engage in a thesis defense

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Thank you