[MUSIC PLAYING]
Hey Nathan, do you know where Leslie is?
Yeah, she's in EJ272.
Thanks.
I have a bagel for her.
[MUSIC PLAYING]
Hey Leslie.
A bagel.
Suppose Stan is not a human being.
Suppose Stan is a robot and has to deliver a bagel to Leslie.
The picture changes.
What is a relatively simple task for Stan
is an extremely challenging one for a robot.
Computer scientists at SRI International
are developing a robot that can perform complex tasks, tasks
that require the robot to have advanced perception,
natural language, and reasoning abilities.
While researchers have made advances
in each of these areas, up to now
few have attempted to combine these technologies
into a single robot.
That's where Flakey comes in.
Flakey, the product of SRI's Artificial Intelligence Center,
is a robot consisting of computers, sensors,
and other hardware.
Flakey's sensors include vision sensors, sonar sensors,
and contact sensors.
Flakey's shaft encoders, sensors connected to the wheels,
can tell how far and how fast the robot has traveled.
A speech recognition system allows those around Flakey
to communicate using voice commands.
You have a bagel.
Enter.
Let's see how Flakey goes about delivering a bagel to Leslie.
Parsing sentence.
You have a bagel.
Finished successfully parsing sentence.
I want Leslie to have the bagel.
Enter.
I want Leslie to have the bagel.
Finished successfully parsing sentence.
Nathan knows where Leslie is.
Enter.
Parsing sentence.
Nathan knows where Leslie is.
Finished successfully parsing sentence.
Nathan is in EJ227.
Enter.
Parsing sentence.
Nathan is in EJ227.
Finished successfully parsing sentence.
Moving to region 13.
[MUSIC PLAYING]
OK.
Well, I'll talk to you later.
Bye bye.
Where is Leslie?
Leslie is in EJ272.
Enter.
Parsing sentence.
Leslie is in EJ272.
Finished successfully parsing sentence.
[MUSIC PLAYING]
Moving to region three.
[MUSIC PLAYING]
Moving to region 18.
[MUSIC PLAYING]
Moving to region 15.
[MUSIC PLAYING]
Take a bagel.
Thank you, Flakey.
We've just seen Flakey deliver a bagel to Leslie.
Now let's take a closer look at how Flakey operates.
Flakey's sensors constantly collect data
from his environment.
The data he gathers must undergo a continual process
of interpretation in order for Flakey
to select actions to perform.
Here's how it works.
Flakey's software is organized into three layers, low, middle,
and high level.
Each layer can interpret incoming information
and carry out certain tasks.
The higher the level, the more abstract
the information and tasks.
Low level tracks Flakey's location
by finding walls and doors.
This computer screen shows a map of the corridors.
It illustrates how the robot uses motion feedback and sonar
measurements to locate and classify surfaces.
By continually matching descriptions of these surfaces
against a stored map of the corridor,
Flakey reduces his uncertainty about his position.
Low level also takes output from the speech recognition system
and collects word sequences that can be interpreted
by higher levels of software.
Finally, low level is responsible for generating
Flakey's speech and for steering him
by controlling the motion of his wheels.
Going up the hierarchy, we come to a middle level
where linguistic processing takes place.
In order for Flakey to understand sentences
that are spoken to him, mid-level
must analyze them and construct a symbolic representation.
This is done using a unification based chart parser.
When Flakey decides to speak, mid-level
must convert symbolic forms into English sentences.
Mid-level uses the same grammar to generate Flakey's sentences
as it does to parse.
Where is Leslie?
Mid-level also sequences and monitors
the execution of robot actions.
At high level, reasoning takes place.
Reasoning is carried out by a deductive system
similar to Prolog but incorporating full first order
deduction.
The deductive system operates on a knowledge base of facts,
including new facts received from mid-level
as well as previously stored facts.
This reasoning process produces a plan of action
that will cause Flakey to achieve his overall goal.
Let's look at some examples of how these three levels interact
to help Flakey reach his goal.
In this instance, Flakey receives a speech command.
I want Leslie to have the bagel.
Enter.
The interpretive process looks like this.
Flakey receives speech input from his sensors.
Low level collects the string of spoken words.
The data is further refined when it reaches mid-level.
Here parsing produces a symbolic formula
that expresses the meaning of the sentence.
The data continues up to high level,
where reasoning takes place and conclusions are drawn.
High level forms plans by projecting the consequences
of alternative actions until finally it selects
the actions to be executed.
In this instance, high level concludes Flakey
should move to region one.
Mid-level initiates the move command and low level
steers the robot to region one by controlling wheel
velocities.
Let's look at another example of the interaction between levels
of this hierarchy.
Here Flakey encounters and obstruction.
His sensors identify a barrier and immediately Flakey stops.
The interpretive process looks like this.
Low level monitors data gathered by the sonar sensors,
detects a closed door, and stops Flakey
without waiting for high level processing.
The information about the closed door travels up from low level
through mid-level to high level.
High level realizes that the closed door
invalidates a key step in the original plan for achieving
the goal.
This leads high level to formulate a new plan involving
an alternate route.
High level concludes that Flakey should move to region two.
As the command is executed, Flakey
turns away from the closed door and begins his new route.
You have seen Flakey follow a command given to him
by Stan, a human being.
Scientists at SRI designed Flakey's software
so he will be able to communicate
not only with human beings but with other robots.
The concept of robots working together in teams
suggests a wide range of new applications.
To make cooperating robots a reality,
however, will require further research
in the area of intelligent communicating agents.
Taking a step into the future, suppose Stan
is out of the picture.
In his place is another robot.
Let's call her Ramona.
Together Flakey and Ramona are a team.
Their teamwork might look something like this.
Ramona, Leslie wants a bagel.
Where is Leslie?
Leslie is in EJ272.
Please take a bagel to Leslie.
OK, Flakey.
[MUSIC PLAYING]