Active and semi–active suspensions for engines and vehicles

Abstract

This paper assesses the future of active engine isolation, and outlines the progyession in sophistication that these devices will be most likely to follow. The passive, fluid–filled engine mount is introduced in several internal configurations. Simple, low bandwidth, activation of these more or less conventional devices is introduced, and performance benefits are described. This simple activation is the first step toward a fully active engine mount. Another step in sophistication is the adaptive engine mount, which will use a relatively slow effector and simple measurements to maximise at all times r.m.s. deflection across the device in some optimal way. This type of control action is discussed. The ultimate goal in engine isolation is an active or semi–active, high bandwidth device that is optimal in some sense. This device will use state measurement and feedback to minimise transmitted force continuously from the engine to the body. Before this approach to engine isolation becomes practical, considerable development in sensors and high speed, low cost effectors is necessary. Some possible configurations of this type of device are presented.