18-05-2013, 01:01 PM
Intelligent Agents
Intelligent Agents.ppt (Size: 2.37 MB / Downloads: 104)
Intelligent Agents
What is an agent ?
An agent is anything that perceiving its environment through sensors and acting upon that environment through actuators
Example:
Human is an agent
A robot is also an agent with cameras and motors
A thermostat detecting room temperature.
Agent function & program
Agent’s behavior is mathematically described by
Agent function
A function mapping any given percept sequence to an action
Practically it is described by
An agent program
The real implementation
Concept of Rationality
Rational agent
One that does the right thing
= every entry in the table for the agent function is correct (rational).
What is correct?
The actions that cause the agent to be most successful
So we need ways to measure success.
Performance measure
Performance measure
An objective function that determines
How the agent does successfully
E.g., 90% or 30% ?
An agent, based on its percepts
action sequence :
if desirable, it is said to be performing well.
No universal performance measure for all agents
Rationality
What is rational at any given time depends on four things:
The performance measure defining the criterion of success
The agent’s prior knowledge of the environment
The actions that the agent can perform
The agents’s percept sequence up to now
Task environments
Actuators (for outputs)
Control over the accelerator, steering, gear shifting and braking
A display to communicate with the customers
Sensors (for inputs)
Detect other vehicles, road situations
GPS (Global Positioning System) to know where the taxi is
Many more devices are necessary
Properties of task environments
Single agent VS. multiagent
Playing a crossword puzzle – single agent
Chess playing – two agents
Competitive multiagent environment
Chess playing
Cooperative multiagent environment
Automated taxi driver
Avoiding collision
Goal-based agents
Current state of the environment is always not enough
The goal is another issue to achieve
Judgment of rationality / correctness
Actions chosen goals, based on
the current state
the current percept