The Optimization of Vehicle Performances Using Dynamic Models with Two Steps 2015-01-0028
This paper presents an industrial application of the Analytical Target Cascading (ATC) methodology to the optimal design of commercial vehicle steering and suspension system. This is a pilot study about the suspension and steering design of a semi medium bus, whose objective is to develop and introduce an ATC methodology to an automobile development process.
In the conventional process, it is difficult not only to find design variables which meet the target of Ride and Handling (R&H) performance using a detailed full car model, but also to figure out the interrelation between the vehicle and its subsystems.
In this study, ATC methodology is used in order to obtain the optimal values such as geometric characteristics satisfying both the vehicle's R&H target and the subsystem (suspension and steering system) 's target. In the framework of ATC, the vehicle is decomposed into two levels - simplified vehicle level and detailed suspension and steering system level - and the target of optimization on each level is variable during the optimization in order to find the optimum not only for the vehicle but also for the suspension and steering system. With a flexible target in each level, the final optimized results can satisfy all the targets of both levels.
By the ATC process using two level models, R&H performances can be checked in the early step of the vehicle developing process, which can save the development cost with the optimum design variables for the R&H and suspension system.