Effect of Time Delay on Active Vehicle Suspensions Equipped with Linear Quadratic Control
Zhang Wenfeng Hu Haiyan
(Nanjing University of Aeronautics and Astronautics, Institute of Vibration Engineering Research. 210016)

Abstract: The paper presents a case study of the effect of time de lay in the control path on dynamic performance of a 1/4 car model of active vehicle suspension equipped with "LQ" control. First, Based on the generalized Sturm criterion, the delay-independent stability for single degree system of a car model is investigated. The stable region for feedback gains is given under the known time delays. Secondly, the delay-independent stability for two degree system of a car model is given and the stable region for arbitrary time delay is give n under various combinations of feedback gains. In addition, the paper deals wit h the stability switches of the car model equipped with "LQ" control under full state feedback. Finally, the effect of time delay on the dynamic performance o f the model is discussed through using numerical simulations in the frequency domain and time domain, respectively. Keywords: stability, time delay, vehicle suspension, LQ control.