Patent ID: 8675179

Claim:
A control system configured to position a movable object in two or more degrees of freedom with respect to another object, the movable object comprising two or more actuators configured to actuate the object, the control system comprising: a set-point generator configured to provide a set-point position quantity for the movable object for each degree of freedom; a position quantity measurement sensor configured to measure a position quantity of the movable object; a subtractor configured to provide for each degree of freedom an error signal by comparing the set-point position quantity and the measured position quantity; a controller configured to control the position quantity of the movable object and comprising a plurality of input-single output controllers, each input-single output controller associated with a particular degree of freedom and providing a control signal in logical coordinates on the basis of the error signal; and a gain scheduling device configured to provide centre-of-gravity control signals in centre-of gravity coordinates of the movable object on the basis of control signals provided by the controller, the centre-of-gravity control signals being used to actuate the movable object, wherein the gain scheduling device comprises a static gain device and a dynamic gain device, the dynamic gain device arranged in parallel with the static gain device so that the static gain device and the dynamic gain device are adapted to receive the same control signals in logical coordinates outputted by said plurality of input-single output controllers, said static gain device including a static relationship between logical coordinates and centre-of-gravity coordinates of the movable object and said dynamic gain device including a dynamic relationship between logical coordinates and centre-of-gravity coordinates of the movable object.