9. Deterministic world Slippery wheels Partial (local) Observability and Stochastic Worlds Deterministic actions; observe only local square Observe only local square; Suck is determ. R/L are stoch. (may fail to move)
10. Slippery wheels Planning and Sensing in Partially Observable and Stochastic World What is a plan to achieve all states clean? [1: Suck ; 2: Right ; ( if A : goto 2); 3: Suck ] also written as [ Suck ; ( while A : Right ); Suck ] Observe only local square; Suck is determ. R/L are stoch.; may fail to move
11. Search Graph as And/Or Tree What do we need to guarantee success? What kind of guarantee?
12.
13. Kindergarten world: dirt may appear anywhere at any time, But actions are guaranteed to work. b1 b3 =UPDATE( b1 ,[ A,Clean ]) b5 = UPDATE( b4,… ) b2 =PREDICT( b1, Suck ) b4 =PREDICT( b3 , Right )
37. Situations as Result of Action Situation Calculus First-order Logic ∃s, p : Goal(s) ∧ s = Result(s0, p) s = Result(s, []) Result(s, [a,b,…]) = Result(Result(s, a), [b,…])
44. Planning Graph Example Add persistence actions (inaction = no-ops) to map all literals in state S i to state S i+1 .
45. Planning Graph Example Identify mutual exclusions between actions and literals based on potential conflicts.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
Editor's Notes
This course: Spiral approach to dealing with complexity
Executing a plan without looking at the world often fails
In the real world actions are at many levels: the action of driving from one city to the next involves a series of intersection-to-intersection actions, each of which involves a sequence of steering wheel, accelerator, and brake actions.
Deterministic, fully observable world: how to get from upper left to clean state?
Conformant plan to clean everything? Didn’t know where we were, but didn’t matter
Slippery wheels: may move, may not. Suck always works.
Slippery wheels: may move, may not. Suck always works.
Does predict add or subtract states? Does update?
What about h(s)? Is that atomic?
In classical planning, schema over finite domain – abbreviation for spelling out individual variables.
![AI: Dealing with Complexity ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)