Variable tracking active suspension system

A method of operating an active suspension system in a vehicle, the method comprising:

• measuring an acceleration of a mass selected from the group consisting of a sprung mass of the vehicle and an unsprung mass of the vehicle;
• determining a distance between the sprung mass and the unsprung mass;
• controlling an actuator, operatively interposed between the sprung mass and an unsprung mass, to apply a force on the sprung mass to control a motion of the sprung mass;
• based on the measurement of the acceleration, applying the force to control the motion in a first frequency range;
• based on the determination of the distance, applying the force to control the motion in a second frequency range lower than the first frequency range.

An active suspension system of a seat in a vehicle, the system comprising:

• at least one actuator operatively interposed between the seat and a vehicle floor, wherein the at least one actuator is configured to apply a force on the seat;
• at least one acceleration sensor configured to measure acceleration of the seat resulting at least partially from road induced perturbations;
• at least one position sensor configured to measure a distance between the seat and the floor;
• a controller configured to control a motion of the seat in a first frequency range, by applying the force with the actuator in a first frequency range, based at least partially on the measured distance, and in a second frequency range, based at least partially on the measured acceleration.