Simulation and CAD in automation and mechatronics

Simulation has developed mainly to meet the need for authorization, and is therefore essentially concerned with dynamic phenomena. In automation, there is a clear need for "simple" or rather "just necessary" dynamic models, from which control laws can be synthesized. The automatician's first simulation tools were analog tube ECUs, followed by integrated circuits. A rapid transition to hybrid ECUs (analog and digital) led to the almost exclusive use of digital ECUs from the 1970s onwards. In terms of standardization, mathematical operators were standardized for analog ECUs, followed by the standardized CSSL language (Continuous System Simulation Language, 1960) [1] . Several simulation tools supported this standard, the leading software in the 1980s being ACSL (Mitchell & Gauthier Associates). It was also in these years that the role of simulation was to be revolutionized by its integration into the design cycle of systems including increasingly sophisticated control electronics, combined with the inescapable need to control the entire system. The need to extend simulation from an activity reserved for a few initiates to the design activities of modern mass-market products, where control electronics not only increase possibilities tenfold, but also call into question design methods hitherto based on a division by scientific disciplines. Indeed, each specialist has a different perspective on the sub-problems posed, and the combination is rarely optimal due to communication barriers between these specialists. This situation can be summed up in the expression that the whole is more than the sum of its parts, in the sense that it is not trivial to deduce the behavior of the whole from the properties of the individual parts.

From this context emerges the idea of "simultaneous design", sometimes called "system approach" or "mechatronics approach", where simulation plays a crucial role.

From this point of view, it is easy to understand why simulation tools designed to help the automation engineer are part of a design assistance platform presented in this article, in which the automation engineer plays a transversal role.