Active engine mounting system using natural logarithm sliding mode control (ln-SMC)

Abstract

This paper discusses Natural Logarithm Sliding Mode Control (ln-SMC) for active engine mounting (AEM) system to isolate engine body vibration. AEM system is designed to deal with isolation of vibration in high level frequency. A number of controllers for AEM system have been proposed. One of them is sliding mode control. However there is no systematic method to determine sliding surface for conventional sliding mode technique to assure the controller able to attenuate the vibration and asymptotically stable. The main advantage of the proposed controller compared to the conventional (linear) sliding mode control is that the magnitude of vibration can be bounded by introducing the nonlinear sliding surface (logarithm function). The result shows that ln-SMC is not only able to attenuate the vibration but also robust to the different types of disturbance and parametric uncertainties such as mass, stiffness, and damping coefficient.