Abstract
Ride is an important attribute which must be accounted in the passenger segment vehicles. Excessive H point acceleration, Steering wheel acceleration, Pitch acceleration can reduce the comfort of the driver and the passengers during high frequency and low frequency rough road events. Therefore, the end objective was to improve SUV ride performances by keeping handling performance attributes same or better than base vehicle. Multi Objective Optimization was carried out by keeping spring, bushing and damper characteristic as the design variables to avoid new system or component development time and cost. To improve the Ride performance, Multi Objective Optimization was carried out by Integrating multi-body model of full vehicle built in the ADAMS/Car® with the optimization tool in Mod Frontier, a cooperative simulation for improving multi-performance of vehicle dynamics, which is useful in the engineering practice. Steady state Cornering, Step Steer and Braking maneuvers are considered for handling and Single bump, Rough road and Long wave pitch road profiles are considered for Ride analysis. Flex body with FTire is used for analysis. The first step in this process is DOE (Design of Experiments method) which allows us to select critical or highly influence input variables and to understand the effect of input variables on output performances. Based on the DOE, the optimization has done using critical parameters. The consequent Optimization leads to select the optimum from various conflicting solutions. By the above approach, we achieved good ride improvement by keeping the Handling performances attributes same or better than base. Single bump H-Point vertical acceleration is improved more than 10 % compare to baseline simulation. Rough road Steering Wheel Vertical Acceleration RMS is improved more than 15 % and H point Vertical acceleration Max and RMS are improved more than 10 % compare to baseline simulation. Long way pitch- H Point Vertical Acceleration Max is improved more than 10% compare to baseline simulation. In this paper, a lot of work has been done in optimization of vehicle handling and ride comfort by establishing multi-body models of the full vehicle and resorting to multi-objective optimization tools for an optimal result. The cooperative optimization provides a convenient and effective way to enhance vehicle handling and ride comfort performances which conflict with each other in developing a chassis system. Using this approach increase the ride performance by keeping the handling attributes same or better than base is made possible