A new passive non-linear damper for automobiles

Abstract

Passive linear suspension systems are limited in their ability to improve ride characteristics owing to the conflicting interdependence between ride comfort, road holding, and space occupied by the suspension system. Non-linear systems can improve the performance of passive designs by de-linking the various metrics involved in ride comfort. Based on the control strategies used in semi-active suspensions, a new non-linear damper design is proposed, where the damping rapidly changes with stroke. This design has been fabricated and tested to validate the analytical expressions governing the damping as a function of stroke. Experimental results show excellent agreement with analytical expressions. The novel damper model has been used along with an existing non-linear spring design, in a quarter-car simulation. The results indicate that the non-linear design leads to significantly lower acceleration levels when compared with a linear system, without any compromise on other metrics.