Hybrid A* Heuristics

The paper Junior: The Stanford Entry in the Urban Challenge is a good read overall, but Section 6.3 - Free Form Navigation is especially good and goes into detail about how the Stanford team thought about heuristics for their Hybrid A* algorithm (which they tended to use in parking lots).

Read section 6.3 of the paper and then answer the following question:

Quiz: Valid Heuristics

If you have two individually admissible heuristic functions h_1 and h_2 , which of the following combinations are also valid?

Check the box next to all admissible combinations.

h1 + h2

(h1 + h2) / 2

min(h1, h2)

max(h1, h2)

SOLUTION:

• (h1 + h2) / 2
• min(h1, h2)
• max(h1, h2)