WATERCRAFT STEERING SYSTEM

• US 20080115713A1
• Filed: 09/21/2007
• Published: 05/22/2008
• Est. Priority Date: 11/17/2006
• Status: Active Grant

• Current Assignee: Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Original Assignee: Yamaha Marine Kabushiki Kaisha
• Inventors: Mizutani, Makoto
• Granted Patent: US 7,540,253 B2
• Time in Patent Office: Days
• US Class Current: 114/162
• CPC Class Codes: B63H 20/12 Means enabling steering
• CPC Class Codes: B63H 25/42 Steering or dynamic anchoring by propulsive elements by jets B63H25/46; Steering or dynamic anchoring by propellers used therefor only; Steering or dynamic anchoring by rudders carrying propellers

Abstract

A boat steering system provides an operator with excellent efficiency and an excellent operation feel during direction guide member deflection by considering and making adjustments based on a running status of the boat. An ECU controls a direction guide member deflection angle limit. The ECU includes and/lor communicates with detectors and the like for detecting one or more of an operation status corresponding to a steering wheel operation, a running status of the boat, recognizing a status of an outboard motor, and detecting a status of an electric motor that roates an outboard motor. The ECU also controls a direction guide member deflection angle limit based on one or more of the detection values.

Claims

1. A boat, comprising a hull, a propulsion unit at a stern of the hull, a steering device comprising a deflectable direction guide member and an electric actuator for deflecting the direction guide member so as to steer the boat, a steering wheel operable by an operator, the steering wheel adapted to provide an actuation signal corresponding to the amount of a steering wheel operation, a controller adapted to receive the steering wheel actuation signal and to direct the electric actuator to deflect the direction guide member, the controller configured to obtain or receive detection data concerning at least one of an operation status corresponding to the steering wheel operation, a running status of the boat, a status of the propulsion unit, and a status of the electric actuator, wherein the controller calculates a direction guide member deflection angle limit based on at least one of the detection data, the direction guide member deflection angle limit being calculated so that direction guide member deflection remains within a range in which the electric actuator maintains a threshold performance level so that steering performance remains advantageous.

2. The boat according to claim 1, comprising an operation status detector that detects at least one of a direction guide member deflection force required for direction guide member deflection, a load to the direction guide member, a direction in which the direction guide member is deflected corresponding to a direction in which the steering wheel is operated and/or the steering wheel operation, and a deviation of a detected actual direction guide member deflection angle from a target direction guide member deflection angle corresponding to the steering wheel operation.

3. The boat according to claim 2, comprising a running status detector that detects at least one of a position of a waterline and a weight of the boat, a trim angle of the boat, and at least one of a speed, an acceleration, a deceleration and a propulsive force of the boat, and an output of the propulsion unit.

4. The boat according to claim 3 additionally comprising an operation storage device for storing therein any one of pieces of information on the installation number of the boat propulsion unit, an installation position of the boat propulsion unit relative to the boat, a rotational direction of a propeller of the boat propulsion unit, a propeller shape, a trim tab angle and a trim tab shape.

5. The boat according to claim 4, comprising an electric actuator status detector that includes a temperature detector for detecting a temperature of the electric actuator.

6. The boat according to claim 5, wherein the electric actuator status detector includes an operating number detector for detecting the number of electric actuators in operation.

7. The boat according to claim 1, comprising a running status detector that detects at least one of a position of a waterline and a weight of the boat, a trim angle of the boat, and at least one of a speed, an acceleration, a deceleration and a propulsive force of the boat, and an output of the propulsion unit.

8. The boat according to claim 1 additionally comprising an operation storage device for storing information on one or more of the installation number of the boat propulsion unit, an installation position of the boat propulsion unit relative to the boat, a rotational direction of a propeller of the boat propulsion unit, a propeller shape, a trim tab angle and a trim tab shape.

9. The boat according to claim 1, comprising an electric actuator status detector that includes a temperature detector for detecting a temperature of the electric actuator.

10. The boat according to claim 9, wherein the electric actuator status detector includes an operating number detector for detecting the number of electric actuators in operation.

11. The boat according to claim 10 additionally comprising a reaction motor for applying a reaction force to the steering wheel, and a reaction motor controller, wherein the reaction motor controller is adapted to increase a reaction force of the reaction motor as the direction guide member approaches the direction guide member deflection angle limit.

12. The boat according to claim 1, comprising an electric actuator status detector that includes an operating number detector for detecting the number of electric actuators in operation.

13. The boat according to claim 1 additionally comprising a reaction motor for applying a reaction force to the steering wheel, and a reaction motor controller, wherein the reaction motor controller is adapted to increase a reaction force of the reaction motor as the direction guide member approaches the direction guide member deflection angle limit.

14. The boat according to claim 1, wherein the propulsion unit comprises an outboard motor, and wherein the direction guide member is part of the outboard motor.

15. A method of steering a boat having a propulsion unit supported by a hull, a direction guide member, and an electric actuator adapted to deflect the direction guide member to effect steering, the method comprising providing a controller adapted to control deflection of the direction guide member, providing a steering wheel adapted to generate a signal corresponding to steering wheel operation, communicating the steering wheel signal to the controller, communicating to the controller detection data concerning at least one of an operation status corresponding to steering wheel operation, a running status of the boat, a status of the propulsion unit, and a status of the electric actuator, and calculating a direction guide member deflection angle limit based on at least one of the detection data communicated to the controller, wherein the direction guide member deflection angle limit is calculated so that the electric actuator will be capable of deflecting the direction guide member up to the direction guide member deflection angle limit while maintaining a desired range of performance.

16. The method of claim 15 additionally comprising providing a reaction motor for applying a reaction force to the steering wheel, the reaction motor being controllable by the controlling, and increasing the reaction force exerted by the reaction motor as the direction guide member approaches the direction guide member deflection angle limit.