Geometric reasoning and symbol grounding in SPARK

All the properties are send to the ontology server ONLY when they change.

Scene status

In the robot's model:
  [Object ID] isMoving true|false

Spatial relationships

At each SPARK iteration, all the following relationships are tested:

for R in [isIn, isOn, isNextTo]
  for obj1, obj2 in Objects:
    check(obj1 R obj2)

for R in [relativePosition]:
  for obj in Objects, agent in Agents:
    check(obj1 R agent)

relativePosition are summarized in this figure:

Updates to the spatial relationships are only sent to the robot's model.

Visibility/Reachability

In EACH agents' model:
  [Object ID] isVisible true|false
  [Object ID] isReachable true|false

Agent focus tracking

Computed facts:

In the robot's model:
  [Agent ID] pointsAt [Object ID]
  [Agent ID] looksAt [Object ID]

Besides, the commonsense.oro.owl ontology contains a rule that infer that:

[Agent ID] pointsAt [Object ID] AND [Agent ID] looksAt [Object ID] -> [Agent ID] focusesAt [Object ID]