Eldad Palachi

Rhapsody: A Complete Life-Cycle Model-Based Development System

We discuss Rhapsody, a UML based software development tool, designed to support complete model-based iterative life-cycle. First, we identify several key inhibiting factors that prevent model-based approaches from being adopted as a mainstream practice.We then examine the requirements for allowing complete life-cycle model-based development and discuss how they are met by Rhapsody through its key enabling technologies, which include: - model-code associativity - automated implementation generation - implementation framework - model execution - model-based testingWe explain why each of these features is instrumental to an effective development of production systems, based on a key observation that the modeling language does not replace the implementation platform, but should be integrated with it in a synergistic manner. This allows the use of modeling for expressing requirements and design abstractions, along with the use of the full power of an implementation language and its supporting platform to specify implementation details. While allowing this flexibility, Rhapsody facilitates full consistency of the modeling and implementation artifacts throughout the life-cycle, and it also supports a high level of automation in the implementation and validation of the developed system.

Model based control system design using sysML, simulink, and computer algebra system

The Systems Modeling Language (SysML) is a standard, general-purpose, modeling language formodel-based systems engineering (MBSE). SysML supports the specification, analysis, and design of a broad range of complex systems such as control systems. The authors demonstrate how they can integrate a SysML modeling tool (IBM Rational Rhapsody) with a proprietary simulation tool (Math Works Simulink) and a Computer Algebra System (CAS) to validate system specification. The integration with Simulink enables users to perform systems engineering process in a SysML model, while designing continuous control algorithms and plant behavior in Simulink, and to validate the behavior by simulating the overall composition in Simulink. The integration with a CAS enables the evaluation of mathematical constraints defined in SysML parametric diagrams. The authors also show the overall approach using a Dual Clutch Transmission (DCT) and a Cruise Control System as examples.

Simulation of cyber physical models using SysML and numerical solvers

We demonstrate a modeling and simulation technique that allows integrating controller/plant behavior specified in numerical solvers, such as Simulink and Modelica, within the SysML model. This allows the mixing of discrete and continuous behaviors in a context of a system model that can be simulated as a complete system level specification. Our approach involves code generation, rather than semantic mappings or model transformation of behaviors, combined with the capability to transform the interface and type specification from one modeling language to the other. Using such complementary languages/tools allows the specification of a complete design model that can be simulated for various purposes such as verification and validation and trade studies.