Construction of New MBD Process for Valve Train That Realizes Multi-Functional and High-Performance Optimal Design in a Short Time

Model-based development (MBD), which makes it possible to study and adjust contradictory requirements between a large number of functions and systems to a high level in a short period of time was implemented within an engine development. In fact, however, elevating engine systems to more advanced levels is a challenge even by satisfying the stand-alone requirements of components. In addition, a still higher level of technology is required for the conflicting relationships between multiple functions, e.g. the power output of an engine and its strength and durability performance, and the reconciliation between the numerous related systems that comprise it. Such reconciling technology requires the consideration of overall optimization that envisions design over a wide range. For present-day development, this would require an extensive period of examination over several years. This presents the issue of requiring an extended period for verification. The valve train, which has multiple functions and is influenced by multiple systems, was therefore taken as the subject of the present research for the purpose of further advancing MBD. The research discussed in this paper conducted a risk analysis in relation to multiple requirements using a design structure matrix (DSM). Quantification of values made it possible to isolate parameters that presented a high risk of rework. Multi-objective design exploration (MODE) was employed to narrow down the design range and satisfy the requested values simultaneously in a short period of time. By this means, the authors sought to create a new MBD process that would reduce development man-hours. The use of a DSM and MODE has increased the efficiency of verification of important parameters, making it possible to realize a new MBD process that reduces the time needed for determination of specifications by 57% against conventional development.