Towards Automated Exploration and Assembly of Vehicle Design Models

Abstract

We describe the use of the Cyber-Physical Modeling Language (CyPhyML) to support trade studies and integration activities in system-level vehicle designs. CyPhyML captures integration interfaces across multiple design domains for system components, and generic design assembly rules given in terms of architecture alternatives. The CyPhyML tools support automated exploration of system-level architectural and parametric tradeoffs using a suite of design exploration tools that can be applied to models at different levels of fidelity and scale. Our overall approach includes exploration over the space of potential designs by evaluating structural combinations and then comparison of designs by simulating the dynamics of systems and subsystems with varying degrees of detail. In that flow, we use the DESERT toolkit for design tradeoffs that can be evaluated from the structure of the design model (i.e. interconnections of components and their parameters). DESERT extends a graphical modeling language with concepts and relations to define structural alternatives and constraints on system properties. Alternatives are given in an abstract way, decoupled from the details of the encoding of the combinatorial design space problem for the underlying binary decision diagram (BDD) solver. For desirable design instance models, the tools automatically assemble complete vehicle or subsystem computer-aided design (CAD) models from the associated component CAD models, and likewise create detailed finite-element structural analysis (FEA) models for selected component assemblies. Evaluation results are presented in a dashboard display which provides comparisons between different valid designs over all specified design metrics.

A Framework for Unambiguous and Extensible Specification of DSMLs for Cyber-Physical Systems

“…Using these tools, we have formalized several languages, both from the physical, computational and CPS integration domains. We have specified the structural and behavioral semantics for hybrid bond graphs, ESMoL (an embedded software modeling language [22]) and CyPhyML (Cyber-Physical Modeling Language [23], [24], [25]). These specifications serve as the formal documentation for our languages, they facilitate correct-by-construction modeling, and serve as a reference implementation for model transformations, that can be used for specification-based testing.…”

OpenMETA: A Model- and Component-Based Design Tool Chain for Cyber-Physical Systems

“…Our approach to improve the predictability of design has been the explicit modeling of multi-physics, multi-abstraction and multi-fidelity interactions and providing methods for composing heterogeneous component models. The OpenMETA design flow is implemented as a multi-model composition/synthesis process that incrementally shapes and refines the design space using formal, manipulable models [3] [19]. The model composition and refinement process is intertwined with testing and analysis steps to validate and verify requirements and to guide the design process toward the least complex, therefore the least risky and least expensive solutions.…”

“…Composition. Model-and component-based technologies are based on composing different design artifacts (such as DAE-s for representing lumped parameter dynamics as Modelica equations [23], input models for verification tools [25], CAD models of component assemblies [19], design space models [25], and many others) from appropriate models of components and component architectures.…”

Towards Automated Evaluation of Vehicle Dynamics in System-Level Designs

“…System requirements drive the specification of component assemblies and design alternatives. Some requirements are modeled as static constraints during automated design space exploration processes [4]. The static constraints eliminate many designs from a set of feasible design candidates, leaving a smaller set of designs for more detailed evaluation.…”