Design of LQR controller for active suspension system

The present paper aims at developing an active suspension for a passenger car by designing a controller using linear quadratic optimal control theory. In this work, two different control approaches are proposed, viz., conventional method (CM) and acceleration dependent method (ADM). A quarter car model with 3 degrees-of-freedom has been considered for the analysis. The performance of the active suspension system with two control approaches has been compared with that of passive one. It is concluded that active suspension system has a better potential to improve both the ride comfort and road holding, since the RMS (Root Mean Square) passenger acceleration has been reduced by 54.23% for active CM system and by 93.88% for active ADM system compared to passive one, and suspension travel has also reduced to about 37.5%.