Behaviour Data Relations Modeling Language

 

Building blocks


BDRML version 1.0

Designing and representing control algorithms is challenging in swarm robotics, where the collective swarm performance depends on interactions between robots and with their environment. The currently available modeling languages, such as UML, cannot fully express these interactions. The Behaviour-Data Relations Modeling Language (BDRML) explicitely represents robot behaviours and data that robots utilise, as well as relationships between them. This allows BDRML to express control algorithms where robots cooperate and share information with each other while interacting with the environment.

BDRML primitives


Primitives are the basic blocks of BDRML. They include:

  • Behaviour: A set of processes that deal with a particular situation a robot finds itself in, for example "Scout"
  • Internal data structure: Information that is stored in a robot's memory
  • External data structure: Information that is stored in a non-robot entity, i.e., in the robot's environment


BDRML primitives

BDRML relations


The following relations between entities can exist:

  • Transition: The robot transitions from one behavioural mode to another
  • Read \ Write: Internal data is used \ stored by the robot engaged in particular behaviour
  • Receive \ Send: External data is used \ stored by the robot. In the case of the Send relation, a robot may also send the data to another robot that stores it in its own internal data structure
  • Copy: Information is copied from one data structure to another
  • Update: The value of a data structure is updated from that in the previous time step by a subroutine not visualised in the BDRML diagram (for example, a pheromone level may spontaneously decrease over time).

The write and send relations can optionally define the new data structure value or a function that updates the value, indicated by a dashed line extending from the end of the relation arrow in a visual description, and written before a colon proceeding the data structure name in a textual description. The update relation always must specify the new value or the value update function.

BDRML relations

BRML relation conditions


Each relation or operation occurs under a specific set of conditions. A condition is visually represented as an annotated triangle at the beginning of a relation or operation arrow. In a textual representation, a condition set follows a relation signature and is separated from it by a colon. Unless otherwise specified, the "or" logical operator is used when multiple conditions affect a single relation.

BDRML relation conditions