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Introduction to Robotics – CS223A

Oussama KhatibTorsten Kroeger

Department of Computer ScienceStanford University

Stanford’s JediBot

Celebrating  50 Years of Robotics!

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Service & Assistance

Haptic Interaction

Main Entry: hap·ticEtymology: from Greek haptesthai to touch

Robotically Aided Surgery

Robotic Catheter Technology

Hansen Medical

..in remote environments

• remote exploration

• instinctive control

• pre operation planning

• assisted navigation

.. human movement understanding

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..in human interaction

• digital actors

• virtual worlds

• synthetic movies

• simulated environments

• social interaction

.. in the human environment

S a f e t y

.. not only walk, but also interact with the world!mobility & whole body compliant manipulation!

Multiple Sensing ModalitiesCombining visual, range, force, and tactile sensing feedback.

Probabilistic framework for globalstate estimation

Sensing and Perception

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.. motion in contact

Compliant Manipulation Primitives

Advanced Manipulation Capabilities

Multi-contact Manipulation

The Challenge

safety & performance

Sensing and Perception

Planning, Control, Skills

real-time, unstructured world

many degrees of freedom

Human-Robot Interaction

Mechanisms and Actuation

cognitive and physical

Interactivity & Human-Friendly

human-like skills, learningmobility and manipulation

Autumn • Introduction to Computer Graphics (CS148, Fedkiw)• Machine Learning (CS229, Ng)•. Introduction to Computer Vision (CS232A, Li)

Winter• Artificial Intelligence: Principles & Techniques (CS221, Liang)• Introduction to Robotics (CS223A, Khatib)• Experimental Haptics (CS277, Salisbury)• Feedback Control Design (E105, Okamura)

Spring• Experimental Robotics (CS225A, Khatib)• Mathematical Methods for Robotics and Vision (CS205, Fedkiw)• Computer Graphics: Image Synthesis Techniques(CS348B, Hanrahan)• Advanced Robotics (CS327A, Khatib)• Can Machines Know? Can Machines Feel? (CS21N, Shoham)• Geometric Algorithms (CS268, Guibas)• Design and Control of Haptic Systems (ME327, Okamura)• Medical Robotics (ME 328, Okamura)

Related Courses

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Professor Oussama KhatibOffice: Gates144 Phone: 723-9753 Email: khatib@cs.stanford.eduOffice hours: MW 4:00 - 5:00

Dr. Torsten KrogerE-mail: tkr@stanford.eduOffice: Gates 122Phone: 725-8810Office hours: MW 4:00 - 5:00

Instructors

Jaeyun Bae Gerald Brantner Mihitha Nutakki Xiyang Yeh

Teaching Assistants

Office: Gates B26B Office hours: Mo 4-5pm, Tu 2-6pm Th 2-3pm

Lecture Notes

Recommended reading:Introduction to Robotics: Mechanics and Control,John J. Craig, Pearson Education, 3rd Edition, 2005

Mechanics, 3rd Edition: Volume 1 - Course of Theoretical Physics, L D Landau, E.M. Lifshitz.

Monday, January 07, 2013 Introduction (read  handout)Wednesday, January 09, 2013 Spatial descriptions 1 (read LN:ch 1)

Monday, January 14, 2013 Spatial descriptions 2 (read LN:ch 1)Wednesday, January 16, 2013 Forward Kinematics 1 (read LN:ch 2)

Monday, January 21, 2013 Holiday (Martin Luther King)Wednesday, January 23, 2013 Forward Kinematics 2 (read LN:ch 2)

Monday, January 28, 2013 Inverse Kinematics  (read LN: ch3)Wednesday, January 30, 2013 Trajectory Generation (read LN: ch6)Monday, February 04, 2013 Jacobians:  Explicit Form (read LN:ch4)

Wednesday, February 06, 2013 Jacobians: Velocities (read LN: ch4)Wednesday, February 06, 2013 Review 1 – Group I (7‐9pm, Gates 119)

Thursday, February 07, 2013 Review 1 – Group II (7‐9pm, Gates 119)Monday, February 11, 2013 Midterm examination (in class)

Wednesday, February 13, 2013 Jacobians:  Static Forces (read LN:ch4)Monday, February 18, 2013 Holiday (President’s Day)

Wednesday, February 20, 2013 Dynamics: Acceleration and Inertia: (read LN:ch5)Monday, February 25, 2013 Dynamics:  Explicit Form (read LN:ch5)

CS223A Lecture and Reading Schedule

Wednesday, February 27, 2012 Vision in Robotics (Guest Lecturer)Monday, March 04, 2012 Control:  PID control (read LN:ch7)

Wednesday, March 06, 2012 Control:  Joint space control (read LN:ch7)Monday, March 11, 2012 Control:  Operational space & Force control (read  LN:ch7)Monday, March 11, 2012 Review 2 – Group I (7‐9pm, Gates 119)Tuesday, March 12, 2012 Review 2 – Group II (7‐9pm, Gates 119)

Wednesday, March 13, 2012 Advanced TopicsMonday, March 18, 2012 Final examination (12:15 ‐ 3:15 p.m.)

CS223A Lecture and Reading Schedule

Introduction to Robotics, CS223A

Mathematical Models• Kinematics• Dynamics

Planning and Control• Motion Planning• Motion Control• Force Control

Advanced Topics

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Stanford’s JediBot

Spatial Descriptions

• Position and Orientation Descriptions• Transformations between Frames

ManipulatorPrismatic Joint

RevoluteJoint

Base End-Effector

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Manipulator Kinematics

• Link Description• Denavit-Hartenberg Notation• Forward Kinematics

Link Description

Link I-1

Axis i

Axis (I-1)

ai-1

i-1

1joint

1Link

0Linknjoint

nLink

1nLink

1iz

1iy 1iR

1ix

nynR

nx

nz0 1,z z

1y

0R 1

1x0x 1R 0y

iyiR

ix

iz

1iLink

ijoint

iLink

1ijoint

2iLink

Kinematic Chain

0R

1R01T

nR( 1)n nT

1nR

Forward Kinematics

Jacobian: Velocities and Forces•Velocities

(end-effector linear and angular velocities)• Forces

(end-effector forces and moments)• Jacobian: relationships

(joint velocities & end-effector velocities)(joint torques & end-effector forces)

Jacobian

{0} angular velocity

linear velocity

vJ q q

x

xn nxFHGIKJ

(

( ) (( ) 6 1)

0 6 1)

v

( 1 )

( 1 )

n x

n x

q

qJoint Angles

Joint Velocities

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The Jacobian (EXPLICIT FORM)i

Pin v j

v j i i inP

End-Effector Linear Velocity

End-Effector Angular Velocity

v Z Z P qi i i i ini

n

i [ ( )].

1

( ). i ii

n

iZ q1

Inverse Kinematics

Finding joint positions given

end-effector position and

orientation

Solvability,

Existence,

MultiplicityClosed Form,Numerical Solutions

Path DescriptionJoint Space TrajectoriesCartesian Space Trajectories

i

l k

j

ttk

t jk

tdjktdij

slope= jk

slope= kl

slope= ij

slope= lm

ti tmtlmtltkltjtij

Midterm Examination (in-class)

Monday, February 11 (2:15 - 3:30 p.m.)

Manipulator Dynamics

• Acceleration and Inertia• Newton-Euler Formulation• Lagrange Formulation

MA23

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ni

fi

fi 1 ni 1

pi1

pCi

Fi

Ni

F f f

N n n f fi i i

i i i C i i C ii i

1

1 1 1( ) ( ) ( )p p p

Newton-Euler

vcii

Pci

Link i

K m v v Ii i CT

C iT C

i ii i

1

2( )

K Kii

n

1

Total Kinetic Energy

Explicit FormLagrange Formulation

1

2

1

2 1

1

[ ( )

( )

q q qT Ti v

Tv

T CC

i

n

i vT

vT C

Ci

n

M m J J J I J

M m J J J I J

i i i i i

i i i i i

Manipulator Equations of MotionExplicit Form vci

i

Pci

Link i

Mass Matrix

Manipulator Control

• PID Control• Joint Space Dynamic Control• Cartesian Space Dynamic Control

Manipulator Control

M V G( ) ( , ) ( )

m m

m m

m mm

G

G11 12

21 22

1

2

1121 2

122

11212

22

1

2

1

20

0

20

FHG

IKJFHGIKJ FHGIKJ

FHG

IKJFHGIKJ FHGIKJ FHGIKJ

d i

m m m m G

m mm

G

11 1 12 2 112 1 2 122 22

1 1

22 2 21 1112

12

2 22

m2

l2 2

m1l1

1

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F

( )GoalV xF

( )GoalV x

T FJ

Task-Oriented Control

F

dynamics( )F F

x

x Fp

Task-Oriented Dynamics

Manipulator Force Control

• Constrained Motion• Position/Force Control• Contact Stability

Unified Motion/Force Control

motion contactF F F contactF

motionF

Advanced Topics

• Robot Design• Motion Planning• Haptics• Humanoids

Safety

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Safety

Performance

Competing?

Requirements

Human-Friendly Robot Design

: Stanford Human-Safe Robot 2s

: Stanford Human-Safe Robot 2s

: Stanford Human-Safe Robot 2s

Impact-reducingproximity andpressure sensingSkin using SDM

Mobile ManipulationHuman Guided Motion & Human-Robot Interaction

Romeo & Juliet (1993)

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Mobile ManipulationHuman Guided Motion & Human-Robot Interaction

Romeo & Juliet (1993)

Artificial Potential Field -Video

ElasticPlanning

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ElasticPlanning

Human movement

understandinghuman motion

Motion capture

Simulation 79 DOF and 136 MusclesBiometric Data & Bone Geometry (Scott Delp)

Dynamic simulation

Data from Subjects

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Physio-Mechanical Advantage

ASIMO

SAI Neuromuscular Library

Throwing

Football Player

Motion CaptureForce Plate

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Human MotionAtlas

Collision Detection

Collision Resolution

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.. simulating the sense of touch

h a p t i c s

SAI: real-time interactive multi-body simulation

Ultrasound Imaging

Ultrasound Imaging

Haptic Teleoperation

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Haptic Teleoperation

Exploring the Oceans..

Exploring the Oceans..

Final Examination (in-class)

Monday, March 18 (12:15 - 3:15 p.m.)

Course Mechanics• Homework: Weekly Problem Set

- Due 7 days later (30% per day penalty)- All homework must be done individually- All homework must be handed in to receive the final grade

• Grading: Weighted Average(Homework 30%, Midterm 25%, Final 45%)

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Thank You!