Passive and active, fluid and mechanical inerters for vehicle dynamics control

An inerter is a device that generates a force related to the relative acceleration across it. It was invented in the late 1900's and used in F-1 racing for some period of time. In this paper the concept of an inerter is introduced as a passive suspension element alongside conventional springs and shock absorbers. A model vehicle traverses both a single bump and a random roadway and the effect of the inerter is analysed. It is shown to be beneficial for road holding. Several configurations are presented that are being considered for testing. An issue with an inerter is that it requires added unsprung weight. To compensate for this, the concept of a fluid inertia inerter is introduced. Such a device uses fluid as the inertial element and, due to a beneficial geometry, far less fluid mass is needed to achieve the same inerter effect as using physical mass. It is also possible to have an act…