US 7,530,865 B2
	Control device for plural propulsion units
Takuya Kado, Shizuoka-ken (Japan); and Shu Akuzawa, Shizuoka-ken (Japan)
Assigned to Yamaha Hatsudoki Kabushiki Kaisha, Shizuoka (Japan)
Filed on Jan. 25, 2008, as Appl. No. 12/20,499.
Claims priority of application No. 2007-014632 (JP), filed on Jan. 25, 2007.
Prior Publication US 2008/0182464 A1, Jul. 31, 2008
This patent is subject to a terminal disclaimer.
Int. Cl. B63H 21/22 (2006.01)

U.S. Cl. 440—1  [440/86]

13 Claims

1. A propulsion unit control system for a vessel having a plurality of propulsion units arranged side by side and electrically connected in association with two control levers that are controllable by an operator to operate a shift actuator and/or a throttle actuator of a corresponding one of the propulsion units, the control system configured to synchronize the engine rotational speed of a target one of the propulsion units with the engine rotational speed of a reference one of the propulsion units when a specified condition is satisfied, the control system comprising a first control lever corresponding to the reference propulsion unit, a second control lever corresponding to the target propulsion unit, a lever position detector adapted to detect a lever position of the first and second control levers, and an engine rotational speed detection device configured to detect an engine rotational speed of the reference propulsion unit and an engine rotational speed of the target propulsion unit, wherein the control system is configured so that, when a deviation between the first lever position and the second lever position has been equal to or greater than a lever determining value for a first prescribed duration, or when a deviation between the engine rotational speed of the reference propulsion unit and the engine rotational speed of the target propulsion unit has been equal to or greater than an engine speed determining value for a second prescribed duration, engine synchronization is cancelled.