Advanced Topics in Robotics CS493/790 (X)

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Advanced Topics in Robotics CS493/790 (X)

• Lecture 1
• Instructor Monica Nicolescu

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General Information

• Instructor Dr. Monica Nicolescu
• E-mail monica_at_cs.unr.edu
• Office hours Tuesday, Thursday 1100am-noon
• Room SEM 239
• Class webpage
• http//www.cs.unr.edu/monica/Courses/CS493-790/
• Lectures
• Tuesday 930-1045am SEM 344
• Laboratory
• Thursday 930-1045am SEM 246

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What will we Learn?

• Cover fundamental aspects of robotics
• What is a robot?
• Robot control architectures
• Advanced robotics techniques
• Biologically inspired robotics
• Robot learning reinforcement, imitation,
  demonstration, genetic algorithms
• Multiple robot systems coordination and
  cooperation
• Human-robot interaction
• Navigation and mapping
• Hands-on experience

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Readings and Presentations

• Two papers (on average) discussed at each lecture
• Each paper is presented by a student
• Presentation guidelines
• At most 30 minutes
• Briefly summarize the paper
• Discuss the paper, its strengths, weaknesses, any
  points needing clarification
• Addressing any questions the other students may
  have

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Readings and Paper Reports

• For each paper, all students must submit, at the
  beginning of the class a brief report of the
  paper
• Report format (typed)
• Student's name
• Title and authors of the paper
• A short paragraph summarizing the contributions
  of the paper
• A critique of the paper that addresses the
  strengths and weaknesses of the paper

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Project/Lab Testbeds

• The Player-Stage-Gazebo simulator
  (playerstage.sourceforge.net)
• Player is a general purpose language-indepedent
  network server for robot control
• Stage is a Player-compatible high-fidelity indoor
  multi-robot simulation testbed
• Gazebo is a Player-compatible high-fidelity 3D
  outdoor simulation testbed with dynamics
• Player/Stage/Gazebo allows for direct porting to
  Player-compatible physical robots.

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Project/Lab Testbeds

• One Player-compatible ActivMedia Pioneer 3 DX
• sonar sensors
• Laser
• PTZ camera
• Onboard computer
• One Player-compatible ActivMedia Pioneer 1 AT
  robot
• 7 sonar sensors and requires the use of a laptop
  (not provided)
• 16 LEGO robot kits
• Handy Board microcontroller
• Programming in Interactive C

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Project

• Individual project on topics covered in class
• Project topics an implementation of either
• a single robot system (involving complex behavior
  and demonstrated on a physical robot) or
• a multi-robot system (involving cooperation/
  communication/ coordination between robots and
  demonstrated in simulation)

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Project Reports

• Should include the following
• Title, author
• Abstract
• Introduction and motivation
• Problem definition project goals, assumptions,
  constraints, and evaluation criteria
• Details of proposed approach
• Results and objective experimental evaluation
• Review of relevant literature
• Discussion (strengths and weaknesses) and
  conclusion
• References
• Appendix (relevant code or algorithms)

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Class Policy

• Grading
• Paper reports 15
• Paper presentations 20
• Participation in class discussions 15
• Lab assignments 20
• Final project 30
• Late submissions
• No late submissions will be accepted
• Attendance
• Full participation in class discussions

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Important Dates/Milestones

• February 23
• Project topic proposal and presentation
• One page that outlines the specific goals,
  contribution, implementation platform and the
  proposed approach
• April 6
• Project status presentations
• 5 minute in-class presentation
• One-two pages that describe the current status of
  the project, what has been done, what is still to
  be done

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Important Dates/Milestones

• May 12
• Project final presentations 
• Project final demonstrations
• Project final reports due

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Optional Textbooks

• Basic topics
• The Robotics Primer, 2001. Author Maja Mataric'
• Available in draft form at the bookstore
• Advanced topics
• Behavior-Based Robotics, 2001.Author Ron Arkin
• Available at the library
• Lego Robots
• Robotic Explorations An Introduction to
  Engineering Through Design, 2001. Author Fred G.
  Martin

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Key Concepts

• Situatedness
• Agents are strongly affected by the environment
  and deal with its immediate demands (not its
  abstract models) directly
• Embodiment
• Agents have bodies, are strongly constrained by
  those bodies, and experience the world through
  those bodies, which have a dynamic with the
  environment

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Key Concepts (cont.)

• Situated intelligence
• is an observed property, not necessarily internal
  to the agent or to a reasoning engine instead it
  results from the dynamics of interaction of the
  agent and environment
• and behavior are the result of many interactions
  within the system and w/ the environment, no
  central source or attribution is possible

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The term robot

• Karel Capeks 1921 play RUR (Rossums Universal
  Robots)
• It is (most likely) a combination of rabota
  (obligatory work) and robotnik (serf)
• Most real-world robots today do perform such
  obligatory work in highly controlled
  environments
• Factory automation (car assembly)
• But that is not what robotics research about the
  trends and the future look much more interesting

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What is in a Robot?

• Sensors
• Effectors and actuators
• Used for locomotion and manipulation
• Controllers for the above systems
• Coordinating information from sensors
• with commands for the robots actuators
• Robot an autonomous system which exists in the
  physical world, can sense its environment and can
  act on it to achieve some goals

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Challenges

• Perception
• Limited, noisy sensors
• Actuation
• Limited capabilities of robot effectors
• Thinking
• Time consuming in large state spaces
• Environments
• Dynamic, impose fast reaction times

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Uncertainty

• Uncertainty is a key property of existence in the
  physical world
• Physical sensors provide limited, noisy, and
  inaccurate information
• Physical effectors produce limited, noisy, and
  inaccurate action
• The uncertainty of physical sensors and effectors
  is not well characterized, so robots have no
  available a priori models

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Uncertainty (cont.)

• A robot cannot accurately know the answers to the
  following
• Where am I?
• Where are my body parts, are they working, what
  are they doing?
• What did I just do?
• What will happen if I do X?
• Who/what are you, where are you, what are you
  doing, etc.?...

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Classical activity decomposition

• Locomotion (moving around, going places)
• factory delivery, Mars Pathfinder, lawnmowers,
  vacuum cleaners...
• Manipulation (handling objects)
• factory automation, automated surgery...
• This divides robotics into two basic areas
• mobile robotics
• manipulator robotics
• but these are merging in domains like robot
  pets, robot soccer, and humanoids

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Robots Alternative Terms

• UAV
• unmanned aerial vehicle
• UGV (rover)
• unmanned ground vehicle
• UUV
• unmanned undersea vehicle

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An assortment of robots
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Anthropomorphic Robots
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Animal-like Robots
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Humanoid Robots
QRIO
Asimo (Honda)
DB (ATR)
Robonaut (NASA)
Sony Dream Robot
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A Brief History of Robotics

• Robotics grew out of the fields of control
  theory, cybernetics and AI
• Robotics, in the modern sense, can be considered
  to have started around the time of cybernetics
  (1940s)
• Early AI had a strong impact on how it evolved
  (1950s-1970s), emphasizing reasoning and
  abstraction, removal from direct situatedness and
  embodiment
• In the 1980s a new set of methods was introduced
  and robots were put back into the physical world

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W. Grey Walters Tortoise

• Machina Speculatrix (1953)
• 1 photocell, 1 bump sensor, 1 motor, 3 wheels, 1
  battery
• Behaviors
• seek light
• head toward moderate light
• back from bright light
• turn and push
• recharge battery
• Uses reactive control, with behavior
  prioritization

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Braitenberg Vehicles

• Valentino Braitenberg (1980)
• Thought experiments
• Use direct coupling between sensors and motors
• Simple robots (vehicles) produce complex
  behaviors that appear very animal, life-like
• Excitatory connection
• The stronger the sensory input, the stronger the
  motor output
• Light sensor ? wheel photophilic robot (loves
  the light)
• Inhibitory connection
• The stronger the sensory input, the weaker the
  motor output
• Light sensor ? wheel photophobic robot (afraid
  of the light)

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Example Vehicles

• Wide range of vehicles can be designed, by
  changing the connections and their strength
• Vehicle 1
• One motor, one sensor
• Vehicle 2
• Two motors, two sensors
• Excitatory connections
• Vehicle 3
• Two motors, two sensors
• Inhibitory connections

Vehicle 1
Being ALIVE
FEAR and AGGRESSION
Vehicle 2
LOVE
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Artificial Intelligence

• Officially born in 1956 at Dartmouth University
• Marvin Minsky, John McCarthy, Herbert Simon
• Intelligence in machines
• Internal models of the world
• Search through possible solutions
• Plan to solve problems
• Symbolic representation of information
• Hierarchical system organization
• Sequential program execution

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AI and Robotics

• AI influence to robotics
• Knowledge and knowledge representation are
  central to intelligence
• Perception and action are more central to
  robotics
• New solutions developed behavior-based systems
• Planning is just a way of avoiding figuring out
  what to do next (Rodney Brooks, 1987)
• Distributed AI (DAI)
• Society of Mind (Marvin Minsky, 1986) simple,
  multiple agents can generate highly complex
  intelligence
• First robots were mostly influenced by AI
  (deliberative)

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Background Readings

• F. Martin Sections 1.1, 1.2.3
• M. Mataric Chapters 1, 3