Controlling a vehicle damper and differentiating between wheel and body events

A method for controlling a controllable suspension damper for a vehicle wheel comprising the steps of:

• a) obtaining an input signal corresponding to the vertical velocity of the vehicle wheel;
• b) filtering the input signal with a filter to obtain an output signal;
• c) determining the frequency of the input signal using the input and output signals;
• d) applying a vehicle-wheel-event control signal to the controllable suspension damper for at least some determined frequencies greater than a predetermined low value;
• and
• e) applying no vehicle-wheel-event control signal to the controllable suspension damper if the determined frequency is below the predetermined low value, wherein the predetermined low value differentiates between a vehicle wheel event and a vehicle body event.

A method for controlling a magnetorheological suspension damper for a vehicle wheel comprising the steps of:

• a) obtaining an input signal corresponding to the vertical velocity of the vehicle wheel;
• b) filtering the input signal with a lead-lag filter to obtain an output signal;
• c) determining the frequency of the input signal using the magnitudes of the input and output signals;
• d) applying a vehicle-wheel-event control signal to the magnetorheological suspension damper for at least some determined frequencies greater than a predetermined low value;
• and
• e) applying no vehicle-wheel-event control signal to the magnetorheological suspension damper if the determined frequency is below the predetermined low value, wherein the predetermined low value differentiates between a vehicle wheel event and a vehicle body event.