Autopilot system

• US 5,235,927 A
• Filed: 10/29/1992
• Issued: 08/17/1993
• Est. Priority Date: 12/22/1989
• Status: Expired due to Term

• Current Assignee: Raymarine UK Limited (Teledyne Technologies Incorporated)
• Original Assignee: Nautech Limited (Teledyne Technologies Incorporated)
• Inventors: Singh, Harjit, Clark, Andrew W.
• Primary Examiner(s): Basinger, Sherman
• Assistant Examiner(s): Brahan, Thomas J.
• Application Number:
  US07/968,257
• Time in Patent Office: 292 Days
• Field of Search: 114/144 E, 114/144 R, 244/197, 318/588
• US Class Current: 114/144.00E
• CPC Class Codes: B63H 25/24 by electrical means
• CPC Class Codes: G05D 1/0061 for transition from automatic pilot to manual pilot and vice versa

Abstract

An autopilot system for a vessel such as a boat has an autopilot unit connected via a drive to the rudder or other direction determining means of the vessel. When the autopilot unit is operating normally, direction information from e.g. a heading sensor is processed by the autopilot unit and the drive is controlled by the autopilot unit to determine the appropriate position of the rudder. The rudder is also linked to a steering wheel or other manual steering arrangement. When the steering wheel is moved during normal operation of the autopilot unit, this causes an interference with the control of the rudder by the drive and, if this interference has sufficient magnitude and duration, this triggers override of the autopilot unit, returning the vessel to manual control via the steering wheel. The override may alternatively be triggered by detection of rudder movement by a sensor.

Claims

1. An autopilot system for a marine vessel comprising a steering system including means for determining the direction of movement of the vessel and user operable means for controlling the direction determining means, an autopilot unit for automatically controlling the direction determining means, and means for overriding the control of the direction determining means by the autopilot unit;

wherein the override means is operatively connected to the steering system and arranged such that actuation of the user operable means causes the actuation of the override means, and further wherein the override means is arranged to be actuated when the actuation of the user operable means exceeds a predetermined magnitude of actuation for a predetermined duration of actuation.

2. An autopilot system according to claim 1, wherein the direction determining means is a rudder, and the override means includes means for detecting the displacement of the rudder.

3. An autopilot system according to claim 1, wherein the steering system further includes a linkage (11,13) between the direction determining means (10) and the user operable means (12) and the override means is arranged to detect changes in said linkage (11,13) due to actuations of said user operable means (12).

4. An autopilot system according to claim 3, wherein the override means is arranged to detect changes in said linkage as an interference to said autopilot unit.