Chassis Design Process Automation Using PIDO Technology

摘要

This study builds a web-based chassis design process and database system and applies an optimization approach to replace an iterative decision-making procedure with manual operation. Through an automated optimal design process of this study, critical performance targets and major design variables can be quickly and reasonably determined. The chassis design process consists of four steps where each step summarizes the design results and uploads them to a database system in standard report forms. The conventional chassis design process tries to satisfy design requirements by using performance targets and basic knowledge. Four steps of the process characterize ride and handling performances and dependencies among performances and design variables. Using the dependency, chassis design variables are to be decided so as to satisfy many target performances with considering performance conflicts. However, decision making by trial and error is time-consuming and makes improvements of vehicle performances difficult. In this study, a web-based chassis design process is developed using the process integration capability of PIAnO, a commercial PIDO (Process Integration and Design Optimization) tool. The process executes four modes step-by-step. Following the procedure provided with design know-how at each mode, the chassis design engineer can obtain the design results that satisfy the design requirements specified. For the design engineer to intuitively understand performance tradeoffs, a realtime parametric study tool is provided by using meta-modeling and visualization techniques. Also, in order to efficiently determine the tire and suspension characteristics that simultaneously satisfy target ride and handling performances, PQRSM (Progressive Quadratic Response Surface Method), a function-based sequential approximate optimizer embedded in PIAnO, is utilized instead of the conventional trial and error approach. Moreover, all the data accumulated during a chassis design process are stored in the central database system so that the accumulated data can be conveniently reused on the web-based system to offer a good initial design or a reference design for a new chassis design. The web-based chassis design process and database system built in this study is proved to efficiently and intelligently obtain design results satisfying all the design requirements by exploiting the standardized design procedure including design know-how, optimization, and realtime parametric study, and the conveniently reusable design data accumulated during the previous chassis designs.