UML – robocluedo rosplan – in a nutshell

Contents

elements

nodes and components:

  • knowledge base

  • problem interface

  • planning interface

  • parsing interface

  • plan dispatcher

… actions …

  • feedback manager

  • rosplan kb interface

  • rosplan pipeline manager

UML – Architecture (simplified)

here’s a essential representation of the package plus the ROSPlan system, controlled by this package:

@startuml scale 0.7 ''' DIAGRAM INFOS title "robocluedo rosplan" skinparam Padding 8 left to right direction ''' DIAGRAM ELEMENTS package "robocluedo rosplan" { file "pddl\ndomain" as PDDL_DOM file "pddl\nproblem" as PDDL_PROB package "ROSplan" { database "knowledge base" <<ROSPlan>> as KB [problem interface] <<ROSPlan>> as PROBLEM [planning interface] <<ROSPlan>> as PLAN [parsing interface] <<ROSPlan>> as PARSE [plan dispatcher] <<ROSPlan>> as DISPATCH KB -- PROBLEM PROBLEM -- PLAN PLAN -- PARSE ' KB -- PARSE PARSE -- DISPATCH ' KB -- DISPATCH } package "actions dispatch" as ACTION { node actions } [feedback\nmanager] as FEEDBACK [ROSPlan\npipeline manager] <<node>> as MANAGER [KB interface] <<node>> as IKB DISPATCH -- ACTION PDDL_DOM -- KB PDDL_PROB -- KB IKB -- KB ACTION -- FEEDBACK FEEDBACK -- MANAGER PROBLEM -right- MANAGER PLAN -right- MANAGER PARSE -right- MANAGER DISPATCH -right- MANAGER } () "service pipeline manager" as SRV_MANAGER MANAGER --> SRV_MANAGER () "KB interface service" as SRV_IKB IKB --> SRV_IKB IKB <--> MANAGER @enduml

Blocks

let’s see better some important blocks:

  • the rosplan pipeline manager controls the steps the ROSPlan architecture uses to make and execute the plan, from the problem loading phase to the dispatch. Another fundamental functionality provided by this block is to make explainable possible problems that could occur during the planning, with a rich feedback send to the node using the pipeline manager.

  • the service for dispatching the plan provides just two informations: if the plan has been executed successfully, and if the goal has been fulfilled at the end of the dispatch, and unfortunately nothing else. Here’s where the feedback manager comes in: role of the feedback manager is to make the ROSPlan actions able to explain in details each possible “problematic” situation which could happen during the plan dispatch. The action encountering something wrong publishes a precise type of feedback through a topic reserved for the feedback exchange, and the ROSPlan pipeline manager exploits such a feedback to explain what’s wrong with the last plan dispatch.

  • another fundamental tool inside the package is the so-called KB interface, which provides the ability to modify the predicates of the problem instance inside the knowledge base. This eposes services making easier to replan as well as to alter and to read the informations inside the knowledge base. Its implementation follows the particular characteristics of the PDDL domain, hence one of its roles is to hide the spcificity of the PDDL problem, providing a general, flexible interface for handling the problem in a (kinda) “standard” way.

  • the dispach can interact with the system using a bunch of both ROS actions and Simulated Actions, enabling the system to perform functionalities such as navigation and manipulation.