Patent ID: 7152547

Claim:
A helipad motion compensation system for a vessel, comprising: at least three controllable length actuators operatively coupled between the helipad and the vessel; a first attitude sensor configured to measure an attitude of at least one of the helipad and the vessel along at least one direction; a second attitude sensor configured to measure motion of at least one of the helipad and the vessel alone a second direction orthogonal to the at least one direction; a controller in operative communication with the first and second sensors and the at least three actuators, the controller configured to operate the actuator to substantially maintain an attitude of the helipad to compensate for motion of the vessel along the first and second directions; and at least one acceleration sensor configured to measure vertical acceleration of at least one of the vessel and the helipad, the at least one acceleration sensor in operative communication with the controller, and wherein the controller is configured to operate the at least three actuators to maintain the helipad at a substantially constant geodetic elevation.