1. AuRA: Autonomous Robot Architecture From: Integrating Behavioral, Perceptual, and World Knowledge in Reactive Navigation Ron Arkin, 1990

2. Architecture

3. Hierarchical Planning 1. Generate possible linear segments

4. Hierarchical Planning 2. Find a piecewise linear plath

5. Hierarchical Planning 3. Generate a sequence of schema groupings

6. Using World Knowledge & Reactive Schemas World knowledge can be used to determine the general area in which to move or look for a landmark When the landmark is found, then reactive navigation takes over Arkin’s claim: World knowledge is necessary for efficient, flexible, and generalizable navigation Do you agree?

7. Docking

8. Docking in a Cluttered Environment

9. Long Term Memory for persistent, a priori info Short Term Memory for dynamically acquired info Cartographer for building a map Homeostati c control to monitor internal conditions

10. Discussion Questions What is the best way of handling traps in vector potential fields? Noise addition, deadlines, or ?? Can the noise schema ever cause the robot to become trapped beyond its capability to recover? Are there times when the methodology of low-level reactive planning will fail? What would happen if a motor schema failed to activate correctly, say, due to a hardware failure? Could the robot self-correct?

11. Discussion Questions The output of the schemas is a velocity vector. Are we assuming a nearly instantaneous change in velocity or a delay? In the experiments conducted, a particular velocity is used. What if the velocity were increased? How does the schema-based navigation relate to the way humans make navigational decisions? How would the potential field navigation be adaptable to 3 dimensions?

12. 3D Schema-Based Navigation

13. Discussion Questions If the perceptual schema confidence exceeds the motor schema threshold for action, the motor schema starts to produce a repulsive field surrounding the obstacle. Why? What happens if obstacles suddenly appear or disappear? How does the robot adapt? What environments are idea for the use of schema-based navigation?