Computer-aided engineering capabilities continue to evolve and expand as the increasing power of desktop computers lets software vendors develop more powerful software. At the same time, the decreasing cost of these computers enables users to take advantage of the productivity benefits these CAE packages offer.
One of the newest branches of CAE gaining popularity is Model-Based Design. Model-Based Design lets engineers develop system-level simulation models that mathematically describe the dynamic behavior of devices and equipment. The models incorporate multiple domains of engineering, including, but not limited to, mechanical, electrical and control systems. Model-Based Design is well suited for mechatronic development, with an emphasis on embedded control development.
Why is Model-Based Design rapidly gaining the attention of equipment makers wrestling with the complexities of developing embedded control systems? The benefits boil down to the documented fact that Model-Based Design reduces the time and costs associated with traditional approaches that usually involve prototype design on the actual system hardware. Performing Model-Based Design lets you find errors early in the simulation stage of the project, instead of during the hardware phase where problems are more difficult to trace and costly to fix. In Model-Based Design, the final stages involving hardware prototype tests are done to validate good designs, not to catch bad designs.
The concept of Model-Based Design should be familiar to engineering managers who witnessed the evolution of CAD. In Model-Based Design, the simulation model is a mathematical specification of the system, much as a 3-D CAD file is a geometric specification. The idea of a model as a specification is an important concept. Models in both Model-Based Design and CAD represent unambiguous definitions of the product, dynamically and geometrically, respectively. This table, above, explains the parallels of these CAE solutions.
Model-Based Design presents capabilities not obtainable from other CAE areas. Because it involves multi-domain modeling, engineers can use Model-Based Design to:
Optimize the entire system with respect to the overall electromechanical architecture and control strategy.
Perform design trade-offs for different transient and steady-state operating scenarios.
Conduct formal verification, validation and testing including requirements traceability.
Simulate the combined digital and analog aspects of a design to determine the effects of sampling rates on system performance.
Generate code (C code, HDL, IEC 61131-3) automatically for real-time simulations of the equipment and embeddable control algorithms.
One of the most valuable benefits of Model-Based Design is the time savings associated with automatic code generation. Real-time simulations of equipment let control engineers develop and test their control strategies long before actual hardware is available. Doing this early in the development process can help all engineering disciplines involved understand the dynamic interaction of their respective systems and have more meaningful design trade-off discussions.