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Artificial Intelligence Planning
Introduction and Overview

Artificial Intelligence Planning
•Introduction and Overview

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Overview
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What is Planning (in AI)?
A Conceptual Model for Planning
Planning and Search
Example Problems

Overview
What is Planning (in AI)?
•now: what do we mean by (AI) planning?
•A Conceptual Model for Planning
•Planning and Search•Example Problems

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Human Planning and Acting
• acting without (explicit) planning:
– when purpose is immediate
– when performing well-trained behaviours
– when course of action can be freely adapted

• acting after planning:
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when addressing a new situation
when tasks are complex
when the environment imposes high risk/cost
when collaborating with others

• people plan onlywhen strictly necessary

Human Planning and Acting
•humans rarely plan before acting in everyday situations
•acting without (explicit) planning: (may be subconscious)
•when purpose is immediate (e.g. switch on computer)
•when performing well-trained behaviours (e.g. drive car)
•when course of action can be freely adapted (e.g. shopping)
•acting after planning:
•when addressing a newsituation (e.g. move house)
•when tasks are complex (e.g. plan this course)
•when the environment imposes high risk/cost (e.g. manage nuclear power
station)
•when collaborating with others (e.g. build house)
•people plan only when strictly necessary
•because planning is complicated and time-consuming (trade-off: cost vs.
benefit)
•often we seek only good rather than optimal plans

3Defining AI Planning
• planning:
– explicit deliberation process that chooses and organizes
actions by anticipating their outcomes
– aims at achieving some pre-stated objectives

• AI planning:
– computational study of this deliberation process

Defining AI Planning
•planning:
•explicit deliberation process that chooses and organizes actions by
anticipating their outcomes
•in short:planning is reasoning about actions
•aims at achieving some pre-stated objectives
•or: achieving them as best as possible (planning as optimization
problem)
•AI planning:
•computational study of this deliberation process

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Why Study Planning in AI?
• scientific goal of AI:
understand intelligence
– planning is an important component of rational
(intelligent) behaviour

• engineeringgoal of AI:
build intelligent entities
– build planning software for choosing and
organizing actions for autonomous intelligent
machines

Why Study Planning in AI?
•scientific goal of AI: understand intelligence
•planning is an important component of rational (intelligent) behaviour
•planning is part of intelligent behaviour
•engineering goal of AI: build intelligent entities
•buildplanning software for choosing and organizing actions for
autonomous intelligent machines
•example: Mars explorer (cannot be remotely operated)
•robot: Shakey, SRI 1968

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Domain-Specific vs.
Domain-Independent Planning
• domain-specific planning: use specific representations and
techniques adapted to each problem
– important domains: path and motion planning, perception planning,manipulation planning, communication planning

• domain-independent planning: use generic representations and
techniques
– exploit commonalities to all forms of planning
– leads to general understanding of planning

• domain-independent planning complements domain-specific
planning

Domain-Specific vs. Domain-Independent Planning
•domain-specific planning: use specific representations andtechniques
adapted to each problem
•important domains: path and motion planning, perception planning,
manipulation planning, communication planning
•domain-independent planning: use generic representations and techniques
•exploit commonalities to all forms of planning
•saves effort; no need to reinvent same techniques for different
problems
•leads to general understanding of planning...