On the Ride Comfort Benefits available from Road Preview with Slow-active Car Suspensions

SUMMARY

The potential for road preview information to improve the ride comfort performance of an active suspension with limited control bandwidth is assessed theoretically. A half-car model is augmented by a Padd filter to represent the wheelbase travel time, making the system have only a single input, that to the front axle. Extended continuous time Linear Quadratic Gaussian optimal control theory is then used to establish control laws which minimise cost indices containing various weighting constants. The indices are evaluated for several combinations of vehicle speed, preview time and control bandwidth and conclusions are drawn on the value and usage of the preview information as functions of the operating conditions.