1. CS 4630: Intelligent Robotics and Perception
Planning (Chapter 2)
Instructor: Tucker Balch
Wonderful to be here!
This is work led by me in collaboration with my graduate students at CMU
I am going to focus on work begun over the last year that I plan to continue in the future
General -- collaborations

2. The Hierarchical Paradigm
World Model
Planner
Sensors
Actuators
The Environment
Tucker Balch
BORG Lab
CS 4630

3. Hierarchical Architectures
What is a robot architecture?
A method of implementing a paradigm, of embodying the principles in some concrete way.
Example hierarchical architectures
Nested Hierarchical Controller
RCS
Tucker Balch
BORG Lab
CS 4630

4. Nested Hierarchical Controller (Meystel)
Mission Planner
Goal
World Model
Navigator
Path
Pilot
Turn/Drive
Low Level Controller
Sensors
The Environment
Tucker Balch
BORG Lab
CS 4630

5. NHS Interleaves planning and acting (unlike Strips)
Revises plan if new information comes available
Disadvantage
Only appropriate for navigation tasks
Decomposition is specific to navigation
Tucker Balch
BORG Lab
CS 4630

6. Real-time Control System (Albus)
Sense
Model/Plan
Act
Time scale
The Environment
Tucker Balch
BORG Lab
CS 4630

7. Difficulties with Planning/Hierarchical Architectures
Closed world assumption:
The world model contains everything the robot needs to know
Even if closed world assumption is true
Models are huge
Hard to maintain
Poor or no handling of uncertainty and failure
Tucker Balch
BORG Lab
CS 4630

8. The Frame Problem How to maintain the world model? Tucker Balch
BORG Lab
CS 4630

9. Assignments
Chapter 3 by Friday
Tucker Balch
BORG Lab
CS 4630