Reverse operation control for watercraft

• US 7,399,210 B2
• Filed: 06/24/2004
• Issued: 07/15/2008
• Est. Priority Date: 06/24/2003
• Status: Active Grant

• Current Assignee: Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Original Assignee: Yamaha Marine Kabushiki Kaisha
• Inventors: Yoshimasa, Kinoshita
• Primary Examiner(s): Vasudeva; Ajay
• Application Number:
  US10/876,283
• Publication Number:
  US 20040266286A1
• Time in Patent Office: 1,482 Days
• Field of Search: 440/1, 440 84- 87
• US Class Current: 440/1
• CPC Class Codes: B63H 21/22 the propulsion power units being controlled from exterior of engine room, e.g. from navigation bridge; Arrangements of order telegraphs
• CPC Class Codes: B63H 21/24 the vessels being small craft, e.g. racing boats
• CPC Class Codes: F02B 61/045 for outboard marine engines
• CPC Class Codes: F02D 11/105 characterised by the function converting demand to actuation, e.g. a map indicating relations between an accelerator pedal position and throttle valve opening or target engine torque
• CPC Class Codes: F02D 2250/26 by applying a torque limit
• CPC Class Codes: F02D 29/02 peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers
• CPC Class Codes: F02D 41/0225 in relation with the gear ratio or shift lever position
• CPC Class Codes: F02D 41/2422 Selective use of one or more tables

Abstract

A watercraft has an engine that is controlled to provide a slower operational watercraft speed during a reverse operation of the watercraft. The engine is controlled by detecting a reverse operation and an operator engine torque request. An operational characteristic of the engine (e.g., engine speed) is adjusted to decrease the engine output by a predetermined amount after it is determined that the watercraft is in reverse operation.

Claims

1. A method of controlling an engine associated with a watercraft having a reverse propulsion device and an engine power output request device operable by a rider of the watercraft, the method comprising controlling the power output of the engine such that the power output of the engine is proportional to a position of the power output request device in accordance with a first proportional relationship when the watercraft is not operating in reverse, determining whether the rider has operated the reverse propulsion device to propel the watercraft in reverse and controlling the power output of the engine such that the power output of the engine is changed proportionally to changes in the power output request device at all points over a range of movement of the power output request device in accordance with a second proportional relationship between the power output of the engine and the position of the power output request device when the watercraft is operated in reverse such that the power output of the engine is less than that corresponding to a state of the power output request device under the first proportional relationship.

2. The method of claim 1, wherein controlling the power output of the engine further comprises decreasing the engine power output in response to determining that the rider has operated the reverse propulsion device.

3. The method of claim 2, wherein controlling the power output of the engine further comprises limiting the engine power output based upon detection of predetermined engine operational conditions.

4. The method of claim 1, wherein controlling the power output of the engine comprises moving a throttle valve such that air flow into the engine is less than that requested by the engine power output request device.

5. A method of controlling an engine associated with a watercraft having a reverse propulsion device and an engine power output request device operable by a rider of the watercraft, the method comprising determining whether the rider has operated the reverse propulsion device to propel the watercraft in reverse and controlling the power output of the engine such that the power output of the engine, when the watercraft is operating in reverse, is less than that corresponding to a state of the power output request device when the watercraft is not operated in reverse, wherein controlling the power output of the engine comprises retarding ignition timing.

6. A method of controlling an engine associated with a watercraft having a reverse propulsion device and an engine power output request device operable by a rider of the watercraft, the method comprising determining whether the rider has operated the reverse propulsion device to propel the watercraft in reverse and controlling the power output of the engine such that the power output of the engine, when the watercraft is operating in reverse, is less than that corresponding to a state of the power output request device when the watercraft is not operated in reverse, wherein controlling the power output of the engine comprises delivering less fuel to at least one combustion chamber of the engine so as to form a non-stoichiometric air/fuel ratio thereby causing the engine to produce less power.

7. The method of claim 6, wherein the non-stoichiometric air-fuel ratio is a lean air-fuel ratio.

8. A watercraft comprising a hull, a reverse propulsion device selectively operable by a rider of the watercraft to propel the watercraft in reverse, an engine disposed within the hull, an engine power output request device operable by the rider of the watercraft, and a control system including a controller configured to determine whether the rider has operated the reverse propulsion device and to control the power output of the engine such that the power output of the engine is proportional to a state of the power output request device in accordance with a first proportion relationship when the watercraft is not operated in reverse, and to control the power output of the engine such that the power output of the engine is changed proportionally relative to changes in a state of the power output request device over a range of states of the power output request device in accordance with a second proportion relationship when the watercraft is operated in reverse such that the power output of the engine under the second proportional relationship is less than that corresponding to a state of the power output request device under the first proportional relationship.

9. The watercraft of claim 8, wherein the engine further comprises an induction system including at least one throttle valve configured to meter an amount of air moving through the induction system, and the control system includes an actuator configured to control movement of the throttle valve.

10. The watercraft of claim 9, wherein the controller is configured to adjust the actuator to provide a power output from the engine that is less than that corresponding to the state of the power output request device.

11. The watercraft of claim 8, wherein the control system includes a reverse switch to determine when the rider operates the reverse propulsion device, and the reverse switch communicates with the controller.

12. The watercraft of claim 11, wherein the controller is configured to control the power output of the engine in accordance with the state of the power output request device if the determined that the watercraft is not in a reverse operation.

13. A watercraft comprising a hull, a reverse propulsion device operable by a rider of the watercraft, an engine, an engine power output request device also operable by the rider of the watercraft, means for determining a reverse operation of the watercraft and means for controlling the power output of the engine such that the power output of the engine is changed in accordance with a first proportional relationship relative to a position of the power output request device when the watercraft is not operated in reverse, and such that the power output of the engine is changed proportionally relative to all movements of the power output request device when the watercraft is operated in reverse in accordance with a second proportional relationship relative to a position of the power output request device in which the power output of the engine is less under the second proportional relationship than that corresponding to a state of the power output request device under the first proportional relationship.

14. A method of controlling an engine associated with a watercraft having a reverse propulsion device and an engine power output request device operable by a rider of the watercraft, the method comprising controlling the power output of the engine such that the power output of the engine is proportional to a position of the power output request device in accordance with a first proportional relationship when the watercraft is not operating in reverse, determining whether the rider has operated the reverse propulsion device to propel the watercraft in reverse and controlling the power output of the engine in accordance with a second proportional relationship between the power output of the engine and the position of the power output request device when the watercraft is operated in reverse such that the power output of the engine is less than that corresponding to a state of the power output request device under the first proportional relationship, wherein the second relationship defines a smooth and continuous proportional relationship between a position of a throttle valve of the engine over the entire range of movement of the power output request device.

15. A watercraft comprising a hull, a reverse propulsion device selectively operable by a rider of the watercraft to propel the watercraft in reverse, an engine disposed within the hull, an engine power output request device operable by the rider of the watercraft, and a control system including a controller configured to determine whether the rider has operated the reverse propulsion device and to control the power output of the engine such that the power output of the engine is proportional to a state of the power output request device in accordance with a first proportion relationship when the watercraft is not operated in reverse, and to control the power output of the engine such that the power output of the engine is proportional to a state of the power output request device in accordance with a second proportion relationship when the watercraft is operated in reverse such that the power output of the engine under the second proportional relationship is less than that corresponding to a state of the power output request device under the first proportional relationship, wherein the second relationship defines a smooth and continuous proportional relationship between a position of a throttle valve of the engine over the entire range of states of the power output request device.