Introduction to Planning
The purpose of planning is to find a sequence of actions that achieves a given goal when
performed starting in a given state. In other words, given a set of operator instances
(defining the possible primitive actions by the agent), an initial state description, and a
goal state description or predicate, the planning agent computes a plan.
What is a plan?
A sequence of operator instances, such that "executing" them in the
initial state will change the world to a state satisfying the goal state description. Goals
are usually specified as a conjunction of goals to be achieved.
Simple Planning Agent:
Earlier we saw that
are able to plan ahead - to consider the
consequences of sequences
of actions - before acting. We also saw that a knowledge-based agents can select actions based on explicit, logical representations of the current state and the effects of actions. This allows the agent to succeed in complex, inaccessible environments that are too difficult for a problem-solving agent
Problem Solving Agents + Knowledge-based Agents = Planning Agents
In this module, we put these two ideas together to build
At the most abstract level, the task of planning is the same as problem solving. Planning can be
viewed as a type of problem solving in which the agent uses beliefs about actions and
their consequences to search for a solution over the more abstract space of plans, rather than over the space of situations