Package com.google.ortools.constraintsolver

Class TypeRegulationsConstraint

  • public class TypeRegulationsConstraint
extends Constraint
    The following constraint ensures that incompatibilities and requirements
    between types are respected.

    It verifies both "hard" and "temporal" incompatibilities.
    Two nodes with hard incompatible types cannot be served by the same vehicle
    at all, while with a temporal incompatibility they can't be on the same
    route at the same time.
    The VisitTypePolicy of a node determines how visiting it impacts the type
    count on the route.

    For example, for
    - three temporally incompatible types T1 T2 and T3
    - 2 pairs of nodes a1/r1 and a2/r2 of type T1 and T2 respectively, with
    - a1 and a2 of VisitTypePolicy TYPE_ADDED_TO_VEHICLE
    - r1 and r2 of policy ADDED_TYPE_REMOVED_FROM_VEHICLE
    - 3 nodes A, UV and AR of type T3, respectively with type policies
    TYPE_ADDED_TO_VEHICLE, TYPE_ON_VEHICLE_UP_TO_VISIT and
    TYPE_SIMULTANEOUSLY_ADDED_AND_REMOVED
    the configurations
    UV --> a1 --> r1 --> a2 --> r2, a1 --> r1 --> a2 --> r2 --> A and
    a1 --> r1 --> AR --> a2 --> r2 are acceptable, whereas the configurations
    a1 --> a2 --> r1 --> ..., or A --> a1 --> r1 --> ..., or
    a1 --> r1 --> UV --> ... are not feasible.

    It also verifies same-vehicle and temporal type requirements.
    A node of type T_d with a same-vehicle requirement for type T_r needs to be
    served by the same vehicle as a node of type T_r.
    Temporal requirements, on the other hand, can take effect either when the
    dependent type is being added to the route or when it's removed from it,
    which is determined by the dependent node's VisitTypePolicy.
    In the above example:
    - If T3 is required on the same vehicle as T1, A, AR or UV must be on the
    same vehicle as a1.
    - If T2 is required when adding T1, a2 must be visited *before* a1, and if
    r2 is also visited on the route, it must be *after* a1, i.e. T2 must be on
    the vehicle when a1 is visited:
    ... --> a2 --> ... --> a1 --> ... --> r2 --> ...
    - If T3 is required when removing T1, T3 needs to be on the vehicle when
    r1 is visited:
    ... --> A --> ... --> r1 --> ... OR ... --> r1 --> ... --> UV --> ...

    • Constructor Detail

      • TypeRegulationsConstraint

        public TypeRegulationsConstraint​(long cPtr,
                                 boolean cMemoryOwn)

      • TypeRegulationsConstraint

        public TypeRegulationsConstraint​(RoutingModel model)

    • Method Detail

      • post

        public void post()
        Description copied from class: Constraint
        This method is called when the constraint is processed by the
        solver. Its main usage is to attach demons to variables.
        Overrides:
        post in class Constraint

      • initialPropagate

        public void initialPropagate()
        Description copied from class: Constraint
        This method performs the initial propagation of the
        constraint. It is called just after the post.
        Overrides:
        initialPropagate in class Constraint