SysML-based Reference Models for Fluid Power Components Chris Paredis, Raphael Kobi Product & Systems Lifecycle Management (PSLM) Center Systems Realization Laboratory G.W. Woodruff School of Mechanical Engineering Georgia Institute of Technology February 14, 2006 www.srl.gatech.edu www.pslm.gatech.edu

Reference Models for Fluid Power Components Aim: To organize knowledge about fluid power components into standardized, reusable and extensible models To develop methods for (re-)using this knowledge in support of the design of fluid power systems Method: Define an ontology for describing fluid power components and systems Define reference models as standardized containers that include knowledge and information about the form, function and behavior of components Formalize the ontology and reference models in SysML Create semantic mappings between SysML and authoring and analysis tools

Initial Focus: Wrapping Modelica Models Make wrappers of Modelica models available in SysML so that they can be used to create models of new systems Not the intent to replace Modelica authoring tools (e.g., Dymola) To use Modelica models, only the interface needs to be available Includes: Modelica connectors + parameters Modelica connectors  SysML InternalProperty Modelica parameters  SysML public value Note: "parameter" denotes a quantity that remains constant for the duration of a simulation Other model info is included for completeness But no semantics – unstructured text

Semantic Mapping: SysML <=> Modelica Modelica is object oriented  many concepts map directly to SysML Examples: Modelica class  SysML class Modelica model SysML block Modelica partial class  SysML abstract class But some mismatches due to richer Modelica semantics Special types of classes: model, record, block, connector, type, package, function encapsulated class  ?? Modelica Real has attributes: unit, quantity, displayUnit, nominal, fixed, start, min, max, … …

Approach: Modelica Profile Extend Semantics of SysML classes Extends Association Semantics Extend Semantics of SysML Types Note: work in progress…feedback welcome

SysML versions of Modelica Libraries Use Modelica Profile to Define the Interfaces of Models in Modelica Libraries Note: work in progress…

Example: Hydraulic Motor [… internal definition of ConMot…] The connectors are defined in this parent model parameters are quantities that remain constant during a simulation, and are publicly accessible

Example: Hydraulic Motor (NOTE: We have been using Artisan RTS SysML v0.9) Modelica (Dymola) SysML (Artisan)

Example: Using Motor in Hydraulic Circuit model VerticalLifter HyLibLight.Pumps.Tank tank; HyLibLight.Pumps.ConMot motor; HyLibLight.Pumps.Basic.IdFlowSource source; equation connect(tank.port_A, motor.port_B); connect(motor.port_A, source.port_B); end VerticalLifter; Automatically Generated Modelica Model

Next Steps Get feedback from SysML community on semantic mapping Expand the semantic mapping for Implement / modify the mapping for updated SysML spec We will wait for update of spec in Artisan RTS Implement tool for automatically mapping Modelica XML libraries into SysML wrappers