W. A. Lindsey, A. M. Spagnuolo, J. C. Chipman and M. Shillor,

A new model for low power active control of automotive suspension is described
and numerically simulated. It is based on the Vertically Compressed Horizontally
Sliding Spring (VeCHSS - pronounced `vex') and is in the form of a nonlinear coupled
system of ordinary differential equations. The numerical simulations indicate
that when the system has one steady state, it is stable; when there are three
steady states two are stable and the middle one is unstable. However,
when there are two steady states, both are unstable, although the system
trajectory is shown to be bounded. The simulations also indicate that the
system, without any controls, can follow a periodic road profile well.