A New Non-Linear Design Method For Active Vehicle Suspension Systems.

A novel non-linear design method based on linear quadratic optimal control theory is presented that applies both to linear and (a wide class of) non-linear systems. The method is easy to apply and results in a globally stabilising, near optimal solution, that can be implemented in real time. The key feature of the design method is the introduction of state-dependence in the weight matrices of the usual linear quadratic cost function, leading to a non-linear design method, even for linear dyanmics. To demonstrate the method, a simple linear suspension model is used, in conjunction with a non-linear state penalty, which better reflects the engineering objectives of active vehicle vibration suppression. Non-linear dynamics can equally well be accommodated. A number of simulations is conducted and compared, favourably with a passively mounted vehicle. These preliminary results indicate the potential of the method.