ACTIVE SUSPENSION CONTROL ON REPEATING SURFACE UNDULATIONS

A control system () configured to control an active suspension system () of a vehicle (), the control system comprising one or more controller (), wherein the control system is configured to: determine () that the vehicle is travelling on or approaching repeating surface undulations; determine () vehicle speed; determine () an indication of surface wavelength of the repeating surface undulations; and control () the active suspension system to control at least one of a leading wheel suspension frequency and a trailing wheel suspension frequency in dependence on the vehicle speed and surface wavelength.