Problem Decomposition: Goal Trees, Rule Based Systems, Rule Based Expert Systems. Planning: STRIPS, Forward and Backward State Space Planning, Goal Stack Planning, Plan Space Planning, A Unified Framework For Planning. Constraint Satisfaction : N-Queens, Constraint Propagation, Scene Labeling, Higher order and Directional Consistencies, Backtracking and Look ahead Strategies.

1. Topic To Be Covered:
I. Planning problem II. strips
III. Solution to block world problem
Jagdamba Education Society's
SND College of Engineering & Research Centre
Department of Computer Engineering
SUBJECT: Artificial Intelligence & Robotics
Lecture No-02(Unit-04)
Prof.Dhakane Vikas N

2. PLANNING PROBLEM
What is Planning Problem In AI?
The planning problem in Artificial Intelligence is about the decision
making performed by intelligent creatures like robots, humans or computer
programs when trying to achieve some goal.
It involves choosing a sequence of actions that will transform the state of
the world and step by step so that it satisfy the goals.
Planning:->Set of Actions.
Action:->Precondition:->For actions to performed there is need of some
preconditions.
:->Effect:-Effect is result of action performed.

3. PLANNING PROBLEM
Planning Generally consist of Following Things:
I. Choose the best rule
II. Applying rule on the problem to get new state.
III. Detect if solution is found.
IV. Detect dead end so that new direction will get explored.

4. strips
What is STRIPS AI?
 After planning problem it is required to solve that problem and to solve
problem planning language or techniques are required.
 Languages should be expressive enough to explain a wide variety of
problems & must allow efficient algorithm to operate on it.
 Planning languages are known as action language.
 STRIPS was such technique/Language founded by Richard fike & Nilsson
in 1971 as an automated planner.
 STRIPS stands for stands for Stanford Research Institute Problem
Solver.
 It's an automated planning technique for finding goals by executing a
domain from the initial state

5. PLANNING PROBLEM
What is STRIPS AI?
 Later on this name was given other formal language .
 STRIPS is foundation for most of the language in order to express
automated planning in current use.
 ADL:(Action Description Language) is an advancement of STRIPS,
proposed by Pednault in 1987

6. Example of block world puzzle
What is Block World Puzzle
Problem?
 Block:-square block of same
size can be stack on one
another.
 Flat surface(Table)
 Robotic arm
 Stack

7. Example of block world puzzle
Rules to Provide Solution for Block World Puzzle Problem
RULE PRECONDITION ACTION
Pickup(X) on(X, table)
clear(X)
handempty
holding(X)
Putdown(Y) Holding(X) on(X, table)
clear(X)
handempty
Stack(X,Y) holding(X)
clear(Y)
On(X,Y)
clear(X)
Unstack(X,Y) On(X,Y)
clear(X)
holding(X)
clear(Y)

8. Example of block world puzzle
Basic Operations:
 stack(X,Y): put block X on block Y
 unstack(X,Y): remove block X from block Y
 pickup(X): pickup block X
 putdown(X): put block X on the table

9. Example of block world puzzle
Example
SOLUTION:
Note: Initially goal state on STACK
always.
I. Compare initial state with goal state if
match then stop, ELSE step (2)
II.POP goal state from stack and apply
suitable rule to perform action
III.If all preconditions of rule satisfied
then perform action.
IV. If any precondition of certain rule
satisfied then just POP that from stack
,don’t perform any action.

10. Example of block world puzzle
Example SOLUTION:
ON(A,B)
Action: stack(A,B)
Precondition: holding(A)
clear(B)
Action: pickup(A)
Precondition: on(A, table)
clear(A)
hand empty