COGS 300
Notes
March 13, 2014
Today’s “Fun” Example: Timo Boll vs. KUKA Robot
In a heavily edited and carefully scripted public relations video, Timo Boll takes on a KUKA robot
in a table tennis match
The Duel: Timo Boll vs. KUKA Robot
The video was released (and shown) at the official opening, March 11, 2014, of the new KUKA
Robotics factory in Shanghai, China
Timo Boll, a former world number one ranked table tennis player, currently is ranked eighth. He
is said to enjoy celebrity status in China. He is an “ambassador” for KUKA in China
Another Example: A Robot Prison Guard
Field trials of the “world’s first robotic prison guard” began in April, 2012, at a prison in Pohang,
South Korea. The robot was developed by the Asian Forum for Corrections (AFC), a South Korean
group of researchers
As designed, the robot does not engage in physical interaction with the prisoners. The next step,
say the designers, is to be able to conduct prisoner body searches
Point your web browser to the Reuters video
Robo-Guard on Patrol in South Korea Prison
which includes comments by AFC Chairman Lee Baik-Chul
Recall: This Week’s Learning Goals
1. To explore the basics of robot control including:
— degrees of freedom (DOF)
— kinematics (forward and inverse), statics, dynamics
— position control (path, velocity, acceleration)
— force control
— hybrid control
2. “Higher level” manipulator centric control
3. Example: cortical control of a prosthetic arm (Velliste et al.)
4. Autonomous robots: drones, humanoid
5. Constraint programming, situated agents (Mackworth)
6. Brain computer interface (BCI) (Sitaram et al.)
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Quiz 1
(Mackworth) The basic idea of network consistency algorithms is that once can efficiently eliminate
non-solutions before constructing
solutions
A)
B)
C)
D)
E)
global, local
local, global
global, global
local, local
None of the above
Quiz 2
(Mackworth) Arc consistency is a simple member of the class of algorithms we called. . .
A)
B)
C)
D)
constraint consistency algorithms
network consistency algorithms
deterministic consistency algorithms
parallel consistency algorithms
Quiz 3
(Mackworth) What metaassumptions exist in a world where a pure GOFAIR robot operates?
A)
B)
C)
D)
E)
There are two agents
The agent executes actions in parallel
Actions occur in a non-deterministic world
All of the above
None of the above
Quiz 4
(Sitaram et al.)
BCIs, respectively
A)
B)
C)
D)
and
are disadvantages for EEG-BCIs and fMRI-
low spatial resolution; complexity of development & usage
ambiguous localization of neuronal activity; high cost
high cost; low spatial resolution
A&B
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Quiz 5
(Sitaram et al.) An fMRI-BCI system is a closed-loop system NOT including which one of the
following subsystems?
A)
B)
C)
D)
E)
Signal acquisition
Signal feedback
Signal analysis
Signal reorganization
Signal preprocessing
Quiz 6
(Sitaram et al.) Which of the following is cited as an application of fMRI-BCI?
A)
B)
C)
D)
E)
Alleviation of chronic pain
Lie detection
Movement restoration following a stroke
Clinical rehabilitation of emotional disorders
All of the above
Situated Agents and Constraints
“Horizontal” Architecture of GOFAIR
Mackworth critiques the “horizontal” architecture of a GOFAIR robot
Figure credit: Mackworth, AI Magazine, 2009
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Note: If we replace “robot” with “human” in Mackworth’s diagram, we could also critique GOFCOGS
GOFAIR Metaassumptions
In a “cartoon” sense, a pure GOFAIR robot operates in a world that satisfies several metaassumptions:
• Single agent
• Agent executes actions serially
• Actions occur in a deterministic world
• World is a fully observable, closed world (i.e., Reiter’s closed world assumption)
• Agent has a perfect internal model of infallible actions and world dynamics
• Perception is needed only to determine the initial world state
• A perfect plan to achieve the goal is obtained by reasoning, and executed in an open loop
Aside: The “closed world assumption” is the presumption that what is not currently known to be
true is false. In contrast, an “open world assumption” holds that lack of knowledge does not imply
falsity.
Mackworth’s main critique of GOFAIR is that work in this paradigm typically fails to distinguish
between the agent’s world model and the world itself “because there really is no distinction in
GOFAIR.” Mackworth calls this “a classic mistake.”
Mackworth claims that GOFAIR robots cannot play soccer! Thus, “robot soccer” is a way forward.
Robocup
RoboCup is an international competition (full name, “Robot Soccer World Cup”)
The stated goal:
“By the middle of the 21st century (2050), a team of fully autonomous humanoid robot soccer
players shall win a soccer game, complying with the official rules of FIFA, against the winner of
the most recent World Cup”
Currently, RoboCup has multiple leagues and subleagues. Each team is fully autonomous in all
RoboCup leagues. Once the game starts, the only input from any human is from the referee
The first Robocup competition was held in 1997 in Nagoya, Japan, with 38 teams from 11 countries participating. The most recent Robocup competition was held in 2013 in Eindhoven, The
Netherlands, with 410 teams from 45 countries participating. The entry from Canada is the UBC
Thunderbots. Aside: The UBC Thunderbot team makes an annual pitch for volunteers.
Quoting from the Wikipedia article on RoboCup
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The contest currently has four major competition domains, each with a number of
leagues and subleagues:
1. RoboCup Soccer
• Standard Platform League (formerly Four Legged League)
• Small Size League
• Middle Size League
• Simulation League
– 2D Soccer Simulation
– 3D Soccer Simulation
• Mixed Reality Competition
• Humanoid League
2. RoboCup Rescue
• Rescue Robot League
• Rescue Simulation League
3. RoboCup@Home (debuted in 2006, and focuses on the introduction of autonomous
robots to human society)
4. RoboCupJunior
• Soccer Challenge
• Dance Challenge
• Rescue Challenge
• General
Robot Soccer: Humble Beginnings
The world’s first robot soccer game
c
Drawing credit: Jim Marin, 2009
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“Vertical” Architecture for Situated Agents
Figure credit: Mackworth, AI Magazine, 2009
(Prioritized) Constraint Satisfaction
Figure credit: Mackworth, AI Magazine, 2009
Constraints in a Simple Robot
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• Level 1: Ball in view
• Level 2: Orient toward ball
• Level 3: Move toward ball
Figure credit: Mackworth, AI Magazine, 2009
Constraint-Based Agent (CBA) Framework
The “math” (i.e., formal methods for constraint-based agents) gets complicated. The CBA framework of Zhang and Mackworth consists of three components:
1. Constraint Nets (CN) for system modeling
2. Timed for-all automata for behavior specification
3. Model-checking and Liapunov methods for behavior verification
Constraint Nets (CN) are an architecture for distributed asynchronous programming languages.
CN programs represent the robot body, the controller, the environment, and the constraints that are
local on the structure and dynamics of each system. Timed for-all automata specify the behavior. Formal verification uses model checking or generalized Liapunov techniques taken from the
standard control literature but generalized for symbolic as well as numerical techniques.
Drones
Drones
An unmanned aerial vehicle (UAV), more commonly referred to as a drone, is an aircraft without
an onboard human pilot
Most drones today are controlled remotely by human operators
Increasingly, drones are becoming autonomous with flight (and actions performed while in flight)
controlled by onboard computers
Journeyman Pictures released a 27 minute documentary Rise of the Machines on October 15, 2012.
Both the video and a transcript are available on-line
The USA is now training more drone pilots than pilots for piloted aircraft. Has “flipping a switch”
as a drone operator become more like our trolley example, whereas firing weaponry from a piloted
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aircraft (or as a soldier on the ground) feels more like our footbridge example. Are the cases
different ethically?
Brain Computer Interfaces (BCI)
Brain-Computer Interface (BCI)
• Assumption: “Stochastically unique” pattern of brain activity for each action pattern (muscle
contractions correspond to force/torque exertions)
• Assumption: “Stochastically unique” pattern of brain activity for each mental state, including
intention to act (motor), perceptions, thoughts, dreams, etc.
• Goal: Have computer “learn” brain activity pattern associated with each mental state
• Issue: How can we measure (dynamically changing) patterns of brain activity?
• Question: How stable are these patterns?
The work described in the two Sitaram et al. papers addresses the issue of how to measure (dynamically changing) patterns of brain activity. Functional Magnetic Resonance Imaging (fMRI) is
one such way.
An fMRI-BCI System
Figure credit: Sitaram et al. IEEE Signal Processing Magazine, 2008
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fMRI
fMRI measures task-induced blood oxygen level-dependent (BOLD) changes that correlate with
neuronal activity in the brain
Advantages:
• Noninvasive
• Real-time fMRI of whole brain images now is feasible
• Very specific regions of the brain can be targeted
Disadvantages:
• Equipment is:
— expensive
— physically cumbersome
— non-portable
• Owing to the strong magnetic fields involved, not all patients can be subjected to fMRIs
fMRI-BCI Major Subsystems
An fMRI-BCI system is a closed-loop system with the following major subsystems:
1. Signal acquisition
— trade-off between spatial and temporal resolution
— response due to BOLD effect lags neuronal activity by 3–6 s
2. Signal preprocessing
— corrections, compensations (and smoothing)
3. Signal analysis
— statistical analysis and generation of functional maps
(the computational “heavy lifting”)
4. Signal feedback
— various auditory and visual feedback modalities
(when part of a patient learning activity)
Sample Exam Question:
Patients diagnosed as in a vegetative state open their eyelids occasionally and demonstrate sleepwake cycles, but completely lack consciousness. By comparision, patients with total locked-in syndrome are aware and awake but cannot move or communicate verbally due to complete paralysis of
all voluntary muscles in the body, including the eyes. A patient with total locked-in syndrome can
easily be miss-diagnosed as being in a vegetative state. Based on material covered in the course,
suggest a way that consciousness could be verified in someone with total locked-in syndrome
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On March 22, 2013 Global TV aired a story, Waking the Brain, that featured the work of Adrian
Owen and his group at Western University, London, Ontario. See also an update aired June 5,
2013.
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