Planning As Search

Planning as Search: There are two main approaches to solving planning problems, depending on the kind of search space that is explored:

1. 1. Situation-space search
2. 2. Planning-space search

Situation-Space Search: In situation space search

• the search space is the space of all possible states or situations of the world
• initial state defines one node
• a goal node is a state where all goals in the goal state are satisfied
• a solution plan is the sequence of actions (e.g. operator instances) in the path from the start node to a goal node

Plan-Space Search

• the search space is the space of all possible plans
• a node corresponds to a partial plan
• initially we will specify an "initial plan" which is one node in this space
• a goal node is a node containing a plan which is complete, satisfying all of the goals in the goal state
• the node itself contains all of the information for determining a solution plan (e.g. sequence of actions)