Fix ambiguities for distances

Describe the bug

We might have a general issue with distances. In the last couple of days we got stuck with the interpretation of distances in several actions and conditions.

• RelativeDistanceCondition #217 (closed)
• LongitudinalDistanceAction #300 (closed), #216 (closed).
• LateralDistanceAction #300 (closed), #216 (closed).
• DistanceCondition #301 (closed)
• RelativeLanePosition #302 (closed)

I seems we are now starting to solve the same problem for any single issue differently.

Proposed solution

Describe (at least) 5 different distance types. Consider aspects like freespace (and orientation), vehicle coordinates, road coordinates, lane distance. The general concept must be applicable to any action/condition/position where distances are used.

Basically 7 distance types are identified:

• Cartesian Distance: Shortest distance between an entity and a referenced entity or a position.
• LateralEntityDistance: Shortest distance in Y direction of an entity's coordinate system to a referenced entity or a position.
• LongitudinalEntityDistance: Shortest distance in X direction of an entity's coordinate system to a referenced Entity or a position.
• LateralRoadDistance: Shortest distance of an entity to a referenced entity or a position measured in the t direction of a road coordinate system.
• LongitudinalRoadDistance: Shortest distance of an entity to a referenced entity or a position measured in the s direction of a road coordinate system.

Optional:

• LateralLaneDistance: Like LateralRoadDistance, but the center line of a lane represents the reference axis.
• LongitudinalLaneDistance: Like LongitudnalRoadDistance, but the center line of a lane represents the reference axis.

Remarks

• Any distance can define freespace=true/false. freespace=true: In this case the distance of the bounding boxes of the two entitys are considered (or if a position is defined, the distance between the entity's bounding box and the defined position).freespace=false: the origins of the two entities coordinate systems are condidered (or if a position is defined, the distance between the origin of the entity's coordinate systems and the defined position)
• Note that for freespace=true any distance types (LateralEntityDistance, LongitudinalEntityDistance...) considers different reference points according to the given orientation (see scetches).

No Ideas about

• Route Distance: How would we unambiguously define a distance where routes ar involved?

Consequences

The different types can be used in any action/condition/position that defines a distance. Some restrictions apply. E.g it is useful to define one of [LongitudinalLaneDistance, LongitudinalEntityDistance, LongitudinalRoadDistance] for LongitudinalDistanceActions.

Sketches

Sketches are given for freespace=true, since freespace=false is less complex. Optional distances (LateralLaneDistance, LongitudinalLaneDistance are not shown). Also, when a position is involved instead of a referenced entity, entity B can be replaced by a position.