| Popis: |
A generalized nonlinear model is formulated for the dynamic analysis of model 9 DOF road vehicle with active suspension systems. The model incorporates a nonlinear suspension spring and nonlinear damping force for active dampers and so, the linear model is formulated similar to Bouzara model. The active dampers are characterized by force generators in accordance with the control laws based upon suspension mass velocity. So, This paper reports on an investigation to determine the spring and damper settings that will ensure optimal ride comfort and road holding road vehicle, on different road profiles and at different speeds for linear and nonlinear vehicle models. The extent to which the ride comfort optimal suspension settings vary for roads of different roughness and varying speeds and the levels of ride comfort and road holding that can be achieved, are addressed. The issues of the best objective function to be used when optimizing and if a single road profile and speed can be used as representative conditions for ride comfort optimization of passive, semi-active and active suspensions, are dealt with. Optimization is performed with the Bees algorithm on a vibration model 9 degree of freedom for speeds ranging from 30 to 90 km/h. It is found that optimizing for a combined driver plus rear passenger seat weighted root mean square vertical acceleration rather than using driver or passenger values only, returns the best results. |
