3. Introduction to
Planning
• Planning is nothing but deciding a
set of actions to be performed in
agent environment based on the
perception to achieve the decided
goal.
• To reach a particular destination
first we should find the best route
and then identify a set of actions to
be done at a particular time is
called planning.
6. Languages used for Planning
STRIPS (Stanford Research Institute Problem Solver)
ADL (Action Description Language)
The expressiveness and extensions of STRIPS are lower
than ADL
7.
8. Planning with STATE SPACE SEARCH
Forward state space search algorithm
Backward state space search algorithm
Heuristic for state space search
9. Forward state space search
◦ It is also called as progression planning.
◦ Planning with forward state-space search is similar to
the problem-solving approach.
◦ Forward search is an algorithm that searches forward
from the initial state of the world to try to find a state
that satisfies the goal formula.
13. Drawbacks of FSSS
FSSS does not address the irrelevant action
problems and this approach quickly bogs
down without a good heuristic.
14. Backward state space search
It is also called as regression planning.
Want to generate possible predecessors of a given goal state, work
backwards toward the initial state.
Backward Planning is also known as backward reasoning or goal directed
reasoning. It is preferred when the branching factor in reverse direction is
less than in forward direction.
Backward planning is sometimes better as we start with the goal and thus
the visibility of the goal helps us choosing the moves
17. Planning Graph
The Planning graph is based on the idea of reachability analysis,
which is a process of computing whether a set of states is
reachable or not from an initial set of states.
Graphplan is an algorithm for automated planning developed by
Avrim Blum and Merrick Furst in 1995.
18. Planning Graph
Planning graphs are an efficient way to create a representation of
a planning problem that can be used to
Achieve better heuristic estimates
Directly construct plans
Planning graphs only work for propositional problems.
