Chapter 5

Outline

• Agents and environments • Rationality • PEAS (Performance measure, Environment, Actuators, Sensors) • Environment types • Agent types

Chapter 2 Intelligent Agents

CS 461 – Artificial Intelligence Aynur Dayanik Bilkent University

Slides are mostly adapted from AIMA

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Agents

• An agent is anything that can be viewed as

– perceiving its environment through sensors and – acting upon that environment through actuators – Assumption: Every agent can perceive its own actions (but not always the effects)

Agents

• Human agent:

– eyes, ears, and other organs for sensors; – hands,legs, mouth, and other body parts for actuators

• Robotic agent:

– cameras and infrared range finders for sensors; – various motors for actuators

• A software agent:

– Keystrokes, file contents, received network packages as sensors – Displays on the screen, files, sent network packets as actuators

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Agents and environments

• Percept: agent’s perceptual input at any given instant • Percept sequence: complete history of everything the agent has ever perceived • An agent’s choice of action at any given instant can depend on the entire percept sequence observed to date • An agent’s behavior is described by the agent function which maps from percept histories to actions: [f: P* A] • We can imagine tabulating the agent function that describes any given agent (External characterization) • Internally, the agent function will be implemented by an agent program which runs on the physical architecture to produce f • agent = architecture + program

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Vacuum-cleaner world

• Two locations: A and B • Percepts: location and contents, e.g., [A,Dirty] • Actions: Left, Right, Suck, oOp

Percept sequence [A,Clean] [A, Dirty] [B,Clean] [B,Dirty] [A,Clean],[A,Clean] [A,Clean],[A,Dirty] … [A,Clean],[A.Clean],[A,Clean] [A,Clean],[A,Clean],[A,Clean] Actions Right Suck Left Suck Right Suck … Right Suck

One simple function is : if the current square is dirty then...