How does a box work?

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How does a box work?
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• Starting state
• Objects OO and box B are at L.
• Goal Objects OO are at M.
• Plan for (O in OO) putin(O,B)
• move(B,L,M)
• repeatchoose(OXremovable(OX,B)),
• takeout(OX,B)
• until(empty(B)).

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STRIPS representation

• Action putin(O,B,L)
• Preconditions at(O,L), at(B,L), box(B)
• Effects in(O,B), at(O,L)
• Action move(B,L,M)
• Preconditions at(B,L)
• Effects at(B,M), at(B,L)
• Action takeout(O,B,L)
• Preconditions in(O,B), at(B,L)
• Effects at(O,L), in(O,B)

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Limitations of STRIPS representation

• No geometry.
• Discrete atomic actions.
• Does not generalize or share knowledge with
  similar situations.

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Scientific Computing

• Equations Newtons laws, impact model.
• Boundary conditions
• Shapes of objects
• External forces on manipulators.
• Solve (numerically) for trajectories.

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Scientific Computing Limitations

• Requires exact specifications for shape and
  action. Cannot handle incomplete knowledge or
  generalization.
• Unstable. Answer is not reliable.
• Generates lots of useless intermediate states
• Only supports prediction, not other types of
  reasoning postdiction, diagnosis, design.

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Knowledge-based qualitative physical reasoning

• Representation for partial specifications of
  shape and action 3D shape, continuous time
• Rules to characterize dynamics of domain
  sufficient to support commonsense inferences
• Effective reasoning strategies for different
  tasks.

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Variants

• Objects can be carried on a tray but greater care
  is needed.
• Large objects can be carried in a milkcrate, but
  small objects will fall through.
• A box with a lid is safe against objects fallling
  out in transit.
• etc.
• Share knowledge.

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Sample rule

• holds(S,openBox(B,INTERIOR,TOP))
• forall(O in OO) holds(S,in(place(O),INTERIOR))
  
• value(S,zeroVelocity(O)
  )
• long(S,S1)
• throughout(S,S1, isolated(OO,B))
• throughout(S,S1, motionless(B)) gt
• holds(S1,stable(OO U B))
• forall(O in OO) holds(S1,in(place(O),INTERIOR))

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And when weve finished boxes

• How do pails and dippers work?