Download CS 8520: Artificial Intelligence

CS 8520: Artificial Intelligence
Robotics
Paula Matuszek
Fall, 2008
What is your favorite robot?
HAL 9000
Robby – Forbidden Planet
Robocop
Data
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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What is a robot?
Definition:
“A robot is a reprogrammable, multifunctional manipulator
designed to move material, parts, tools, or specialized devices
through variable programmed motions for the performance of
a variety of tasks.” (Robot Institute of America)
Alternate definition:
“A robot is a one-armed, blind idiot with limited memory
and which cannot speak, see, or hear.”
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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What are robots good at?
• What is hard for humans is easy for robots.
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Repetitive tasks.
Continuous operation.
Complicated calculations.
Refer to huge databases.
• What is easy for a human is hard for robots.
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Reasoning.
Adapting to new situations.
Flexible to changing requirements.
Integrating multiple sensors.
Resolving conflicting data.
Synthesizing unrelated information.
Creativity.
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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What tasks would you give robots?
• Dangerous
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space exploration
chemical spill cleanup
disarming bombs
disaster cleanup
• Boring and/or repetitive
– welding car frames
– part pick and place
– manufacturing parts.
• High precision or high
speed
– electronics testing
– surgery
– precision machining.
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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What does building robots teach us about
humans?
• How do our sensors work?
– eyes
– brain
• How do we integrate sensors?
• How does our muscular-skeletal
system work?
– How do we grab and hold an object?
• How does our brain process
information?
• What is nature of intelligence?
• How do we make decisions?
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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What subsystems make up a robot?
• Action
– Stationary base
– Mobile
• Sensors
• Control
• Power supply
Robert Stengel, Princeton Univ.
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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Action – do some function.
• Actuators
– pneumatic
– hydraulic
– electric solenoid
• Motors
– Analog (continuous)
– Stepping (discrete increments)
• Gears, belts, screws, levers
• Manipulations
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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Three types of robot actions.
• Pick and place
– Moves items between points.
• Continuous path control
– Moves along a programmable path
• Sensory
– Employs sensors for feedback
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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How do robots move?
• Simple joints (2D)
– Prismatic — sliding along one axis
• square cylinder in square tube
– Revolute — rotating about one axis
• Compound joints (3D)
– ball and socket = 3 revolute joints
– round cylinder in tube = 1 prismatic, 1 revolute
• Degrees of freedom = Number of independent
motions
– 3 degrees of freedom: 2 translation, 1 rotation
– 6 degrees of freedom: 3 translation, 3 rotation
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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Mobility
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Legs
Wheels
Tracks
Crawls
Rolls
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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What sensors might robots have?
• Optical
– Laser / radar
– 3D
– Color spectrum
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Pressure
Temperature
Chemical
Motion & Accelerometer
Acoustic
– Ultrasonic
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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What use are sensors?
• Uses sensors for feedback
– Closed-loop robots use sensors in
conjunction with actuators to gain
higher accuracy – servo motors.
– Uses include mobile robotics,
telepresence, search and rescue, pick
and place with machine vision.
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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Control - the Brain
• Open loop, i.e., no feedback,
deterministic
– Instructions
– Rules
• Closed loop, i.e., feedback
– Learn
– Adapt
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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What are some problems with control of robot
actions?
• Joint play, compounded through N joints.
• Accelerating masses produce vibration, elastic
deformations in links.
• Torques, stresses transmitted depending on end
actuator loads.
• Feedback loop creates instabilities.
– Delay between sensing and reaction.
• Firmware and software problems
– Especially with more intelligent approaches
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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How do you measures of performance of
robot?
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Speed and acceleration
Resolution
Working volume
Accuracy
Cost
Plus all the kinds of evaluation functions we have
talked about for any AI system.
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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Measures of Performance
• Speed and acceleration
– Faster speed often reduces resolution or increases cost
– Varies depending on position, load.
– Speed can be limited by the task the robot performs (welding,
cutting)
• Resolution
– Often a speed tradeoff
– The smallest movement the robot can make
• Working volume
– The space within which the robot operates.
– Larger volume costs more but can increase the capabilities of a
robot
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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Performance (cont.)
•Accuracy
•The difference between the actual
position of the robot and the
programmed position
•Repeatability
•Will the robot always return to the same
point under the same control conditions?
•Varies depending on position, load
•Cost
•Typically a tradeoff – improved
performance on other metrics vs lower
cost
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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How are robots different from automated
machinery?
• Machinery is designed to carry out
a specific task.
– Bottling machine
– Dishwasher
– Paint sprayer
• Robots are designed to carry out a
variety of tasks
– Pick and place arms
– Mobile robots
– Computer Numerical Control
machines
• The lines are becoming blurred.
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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The Future of Robotics.
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Robots that can learn.
Robots with artificial intelligence.
Robots that make other robots.
Swarms
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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Lab:
• Look at a couple of robotic videos and note:
– Which features makes the task something a robot would be used for?
– What are the components of the robot:
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Action
Sensors
Control
Power Supply
• How is their performance?
– Speed and acceleration
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Resolution
Working volume
Accuracy
Cost
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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Some good robotics videos.
• Swimming fish:
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http://vger.aa.washington.edu/research.html
http://www.newscientist.com/article/dn14101-shoal-of-robot-fish-casts-a-wider-data-net.html
• Robot wars:
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http://robogames.net/videos.php
• Japanese robots:
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http://www.ecst.csuchico.edu/~renner/Teaching/Robotics/videos.html (note: about half the
links are broken)
• Social robots:
– http://www.ai.mit.edu/projects/humanoid-robotics-group/kismet/kismet.html
• Miscellaneous Robots:
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http://www.newscientist.com/article/dn9972-video-top-10-robots.html
http://grinding.be/category/robots
• Swarms
– http://www.youtube.com/watch?v=SkvpEfAPXn4
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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Play Robot Constructor
• http://www.channel4.com/science/microsites
/R/robots/constructor.html
• What options does it give you for
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Action
Sensors
Control
Power Supply
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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Will robots take over the world?
• Which decisions can the machine
make without human supervision?
• May machine-intelligent systems
make mistakes (at the same level as
humans)?
• May intelligent systems gamble
when uncertain (as humans do)?
• Can (or should) intelligent systems
exhibit personality?
• Can (or should) intelligent systems
express emotion?
• How much information should the
machine display to the human
operator?
HAL - 2001
Space Odyssey
CSC 8520 Fall, 2008. Paula Matuszek. Slides based on www.jhu.edu/virtlab/course-info/ei/ppt/robotics-part1.ppt and -part2.ppt
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