SYNCHRONIZING MULTIPLE STEERING INPUTS TO MARINE RUDDER/STEERING ACTUATORS

摘要

A steering system (100) includes an incremental helm (102), a control pane l (104), and an autopilot (106) that are electrically connected to a command processor (108). The steering system further includes an autopilot attitude controller (110) and an incremental servo (112) for actuating the rudder. The incremental helm ac ts as a course selector for the autopilot. Upon autopilot engagement, the set headin g is the current heading plus any heading change received from the helm after engagement. A course selection controller (120) employs a helm increment summer (122) an d a washout filter (124) that are initialized to zero upon engagement. The washo ut filter follows short-term course changes but forgets them over a longer time. A disengage threshold block (126) receives the washout filter output and disengages the autopilot if the threshold is exceeded. The course selection controller allows a helmsman to make occasional course changes without automatically disengaging the autopil ot unless the helmsman rotates the helm at a rate that exceeds the threshold. Upon disengagement, the autopilot is inhibited from re-engaging for a short time, after which the autopilot can re-engage when the turning rate approaches zero. The steering system further includes a helm rotation stop that provides the helmsman with rudder stop position feedback, responds to the rudder stops regardless of th e current steering ratio, incorporates a powerful braking action with a low-power mechanism, and provides unidirectional braking at either rudder stop in response to a single steering limit signal.