Intelligent Systems

CS 461: Artificial Intelligence

Introduction Introd ction to Intelligent S stems Systems (agents)

Outline
 Agents and environments  Rationality  PEAS
 Performance measure, Actuators, Sensors Environment,

 Environment types  Agent types
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Agents agent noun: a person or thing that acts … ( (root of Latin agere, to do) g , )

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Agents act = A t AgentFn(percept) tF ( t) sensors agent fn

actuators
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Agents (Some definitions)
• Agent: anything that can be viewed as p g y g perceiving its g environment through sensors and acting upon through actuators • Percept: refers to the agent’s perceptual inputs at any given instant of time • Percept sequence: complete history of everything the agent has perceived th i d • Agent’s action at any instant of time depends on the percept sequence • Agent function: describes an agent’s behavior • Agent program: implementation of agent function
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Agents and environments

 The agent function maps from percept histories to actions: [f: P*  A]  The agent program runs on the physical architecture to produce f agent = architecture + program

Vacuum-cleaner world

 Percepts: location and contents e g [A contents, e.g., [A, Dirty]  Actions: Left, Right, Suck, NoOp

Rational agents
 Tabulation of agent functions
 Describes the agent  Infinite !( for most agents) unless bound on percept sequence

 Rational agent
 Does the right thing  Every entry in the table filled correctly

doing the i ht thing is better than doing the d i th right thi i b tt th d i th wrong thi thing what does it mean by right thing? Right action should cause the agent most successful need some ways t measure success d to
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Tabulation o s p e age t functions abu at o of simple agent u ct o s
Percept sequence p q [A, clean] [A, dirty] [B, clean] [B, dirty] [B di t ] [A, clean], [A, clean] [A, clean][A, [A clean][A dirty] …………………………………… [A, clean], [A, clean], [A, clean] Right Action Right Suck Left Suck S k Right Suck

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Performance measures