The present invention provides an active control system for coupling the
movements of a pair of independently operated manual input devices such as
dual flight control sticks operated by a pilot and co-pilot flying an
aircraft. Each input device is configured to receive manual input data in
the form of angular displacement of the device about one or more
rotational axes. The active control system provides desired tactile
feedback to an operator who displaces one of the manual input devices in
the form of a restorative centering force. If an external system such as
an auto-pilot system is engaged, the restorative force may be in a
direction necessary to reconcile manual displacement of the input device
with a position commanded by the external system, rather than directed
toward the center position. The system also acts to reflect manual
displacement of each input device as a force applied to the other. For
example, when a pilot moves his or her control stick forward, the co-pilot
will feel a like force tending to move the co-pilot's control stick
forward.