COMP 14: Computer Science, Robotics, Artificial Intelligence

June 22, 2000Nick Vallidis

Announcements

P6 is due tomorrowTomorrow is a review class - bring

questions you want answered!!!!

Today

What does a computer scientist do?RoboticsArtificial Intelligence

What's a computer scientist do?

Let's ask Jeeves first: Jeeves' answer

My answer: Computers are a new, complex kind of tool Computer scientists figure out how to do useful

things with computers:graphics & medical imagingnetworkingsharing information (the web)robotics & artificial intelligence!

Where do we work?

There are basically three places that use computer scientists: Academia - colleges and universities for

teaching and research Research institutions - NASA, plus other

companies that do research (Microsoft, Bell Labs, etc.)

Industry - programmers (writing the software that people use on their computers)

Robotics

a robot is basically a mechanism that operates under computer control

The main purpose they serve these days is to do boring, repetitive tasks

The fun ones are research robots and that's what I'll talk about

Basic Robot

Has three parts:

Reads sensors to understand environment

Computes what to do based on sensorsUses actuators to do it

Sensors Computer Actuators

Sensors & Actuators

Many possible sensors: video cameras tilt sensors force sensors

Many possible actuators: Electric motors Hydraulics Pneumatics

Mobile Robotics

All the stuff I've done is in the field called Mobile Robotics. means that robot can move around on its

own power as opposed to most industrial robots, which

are giant arms bolted to the floorThere are two types of mobile robots:

walking robots wheeled robots

Examples, examples

We'll do this by example…Robots I worked on at Carnegie

Mellon: Daedalus Lunar Rover (Nomad) Black Widow

Robot I worked on at NASA: Dexter

Daedalus

Designed to be a planetary explorer

Daedalus

an example of a frame walker

Frame 1:

Frame 2:

Legs

Nomad

Designed to test ideas for a commercial trip to the moon (LunaCorp)

Nomad

Went to the Atacama desert of ChileSearched for meteorites in Antarctica

Is a wheeled robotSuper-cool collapsible steering

mechanismVideo

Dexter

Test robot for doing low-power legged locomotion

Video

Black Widow

My senior thesis research project

Black Widow

Patterned somewhat after an insect (leg length, number of legs)

Patterned somewhat after a crab

Purpose was to try out walking algorithms.

I tested out a training method for neural networks

Artificial Intelligence

Attempts to understand and build intelligent entities

Four different definitions of AI: acting humanly (the Turing Test) thinking humanly thinking rationally acting rationally (this is the goal of

robotics)

Problems that require AI

Natural Language Processing make a computer understand English

Machine Learning change behavior based on experience

Perception of a visual scene be able to pick out people, objects, etc.

Robotics! navigation, accomplishing tasks, etc.

AI Techniques

Some that you've probably heard of: Neural Networks Genetic Algorithms Fuzzy Logic

Others that are popular: Reinforcement learning Probabilisitic reasoning Search techniques

Neural Networks

Based on animal nervous systems:

Neural Network Neuron

Input Links(from other neurons)

WeightedSum

ActivationFunction

Output Links(to other neurons)

A Simple Neural Network

Output

Input

Input

Training Neural Networks

That was Black Widow's neural network to keep the body level.

To train (decide the weights to use in the weighted sums) a NN, you have to give it LOTS of examples

Traditionally, these are generated in simulation or by people I made the robot do the work...

Review tomorrow

BRING QUESTIONS!!!!!