Adaptive air suspension system for automotive applications with lqr control

Abstract

Automobile have become inevitable in our day-to-day lives. An average person spends one to two hours daily on travel. While urban roads are smooth, rural roads are commonly irregular in nature. Long rides on irregular roads and infrastructure problems like uncomfortable seating have a very bad impact on human body. The passengers suffer not only physical pain but also from stress related problems. Various types of suspensions are employed in the vehicles to ensure ride comfort on all types of roads. While the primary job of a suspension is to ensure road-wheel contact without compromising ride comfort, most of the suspensions are seen having contradiction between ride comfort and ride handling. This led to an extensive research on active automobile suspension systems which are capable of providing better ride comfort without compromising ride handling. Airsprings gain more popularity in passenger vehicles with an increase in demand for ride comfort. The airsprings are basically containers made from calendared rubber, enclosed between steel plates and filled with air. The air pressure inside the bellow and the elastic property of the rubber contribute majorly for the properties of airspring. Variable stiffness is achievable with an airspring and thus, ride comfort at various operating loads could be accomplished. This research focuses on obtaining variable stiffness of the airspring based on applied load using apposite control systems. In the past, semi-active and active systems were used to overcome the above-mentioned contradictions and provide superior ride experience to the passengers. An improved analytical design to investigate the static stiffness of a convoluted airspring is developed and presented in this research newline