Watercraft maneuvering system and watercraft including the watercraft maneuvering system

Abstract

A watercraft maneuvering system includes propulsion devices provided on a hull, steerings each including a steering actuator to change a steering angle of a corresponding propulsion device, steering angle sensors to detect the steering angle of the corresponding propulsion device, and steering controllers each configured or programmed to control the steering actuator of the corresponding steering. The steering controllers are configured or programmed to feedback-control the corresponding steering actuator based on an output signal of the corresponding steering angle sensor to achieve a target steering angle. The feedback control includes a first mode using a first feedback parameter, and a second mode using a second feedback parameter. The steering controllers are configured or programmed to perform the feedback control in the first mode when at least one of the propulsion devices is operating, and perform the feedback control in the second mode when all the propulsion devices are not operating.

What is claimed is: 
     
         1 . A watercraft maneuvering system comprising:
 a plurality of propulsion devices provided on a hull;   a plurality of steerings corresponding respectively to the plurality of propulsion devices, and each including a steering actuator to change a steering angle of the corresponding propulsion device;   a plurality of steering angle sensors corresponding respectively to the plurality of propulsion devices to detect the steering angle of the corresponding propulsion device; and   a plurality of steering controllers corresponding respectively to the plurality of steerings, and each configured or programmed to control the steering actuator of the corresponding steering; wherein   the plurality of steering controllers are each configured or programmed to feedback-control the corresponding steering actuator based on an output signal of the corresponding steering angle sensor so as to achieve a target steering angle;   the feedback control includes a first mode in which a first feedback parameter is used, and a second mode in which a second feedback parameter different from the first feedback parameter is used; and   the plurality of steering controllers are each configured or programmed to perform the feedback control in the first mode when at least one of the plurality of propulsion devices is operating, and to perform the feedback control in the second mode when all of the plurality of propulsion devices are not operating.   
     
     
         2 . The watercraft maneuvering system according to  claim 1 , wherein the plurality of steering controllers are each configured or programmed to perform the feedback control in the first mode when at least one of the plurality of propulsion devices has an unknown operation state. 
     
     
         3 . The watercraft maneuvering system according to  claim 1 , wherein the plurality of steering controllers are each configured or programmed to acquire information about operation states of the plurality of propulsion devices, respectively, through communications via a communication network, and to perform the feedback control in the first mode when a communication failure occurs in the communication network. 
     
     
         4 . The watercraft maneuvering system according to  claim 1 , wherein the second feedback parameter is defined so that the steering actuators are lower in at least one of responsiveness or steering speed in the second mode than in the first mode. 
     
     
         5 . The watercraft maneuvering system according to  claim 1 , wherein the second feedback parameter is smaller than the first feedback parameter. 
     
     
         6 . The watercraft maneuvering system according to  claim 1 , wherein
 the plurality of propulsion devices each include an engine to generate a propulsive force by a driving force of the engine;   the plurality of steering controllers are each configured or programmed to perform the feedback control in the first mode when the engine of at least one of the plurality of propulsion devices is operating, and to perform the feedback control in the second mode when the engines of all of the plurality of propulsion devices are not operating.   
     
     
         7 . The watercraft maneuvering system according to  claim 6 , wherein
 the plurality of propulsion devices each include a power generator to generate electric power by the driving force of the engine;   the plurality of steering actuators are each operated with electric power supplied from a battery charged with the electric power generated by the power generator;   the second feedback parameter is defined so that the steering actuators are lower in power consumption in the second mode than in the first mode.   
     
     
         8 . A watercraft maneuvering system comprising:
 a propulsion device provided on a hull and including an engine to generate a propulsive force by a driving force of the engine;   a steering including a steering actuator to change a steering angle of the propulsion device;   a steering angle sensor to detect the steering angle; and   a steering controller configured or programmed to feedback-control the steering actuator based on an output signal of the steering angle sensor so as to achieve a target steering angle; wherein   the steering controller is configured or programmed to perform the feedback control in a first mode in which a first feedback parameter is used when the engine is operating, and to perform the feedback control in a second mode in which a second feedback parameter is used when the engine is not operating, the second feedback parameter being defined so that the steering actuator has a smaller power consumption than in the first mode.   
     
     
         9 . The watercraft maneuvering system according to  claim 8 , wherein
 the propulsion device includes a power generator to generate electric power by the driving force of the engine; and   the steering actuator is operated by electric power supplied from a battery charged with the electric power generated by the power generator.   
     
     
         10 . The watercraft maneuvering system according to  claim 8 , wherein the second feedback parameter is smaller than the first feedback parameter. 
     
     
         11 . The watercraft maneuvering system according to  claim 8 , wherein the second feedback parameter is defined so that at least one of responsiveness or steering speed of the steering actuator is lower than that for the first feedback parameter. 
     
     
         12 . A watercraft maneuvering system comprising:
 a propulsion device provided on a watercraft;   a steering including a steering actuator to change a steering angle of the propulsion device;   a steering angle sensor to detect the steering angle; and   a steering controller configured or programmed to feedback-control the steering actuator based on an output signal of the steering angle sensor to achieve a target steering angle; wherein   the feedback control includes a first mode in which a first feedback parameter is used, and a second mode in which a second feedback parameter smaller than the first feedback parameter is used; and   the steering controller is configured or programmed to select the first mode or the second mode based on a predetermined mode selection criterion.   
     
     
         13 . The watercraft maneuvering system according to  claim 12 , wherein the predetermined mode selection criterion includes a criterion related to a charge/discharge state of a battery that supplies electric power to the steering actuator. 
     
     
         14 . The watercraft maneuvering system according to  claim 12 , wherein the predetermined mode selection criterion includes a criterion related to information about an operation state of the propulsion device. 
     
     
         15 . The watercraft maneuvering system according to  claim 12 , further comprising:
 a second propulsion device different from the first propulsion device; wherein   the predetermined mode selection criterion includes a criterion related to information about an operation state of the second propulsion device.   
     
     
         16 . The watercraft maneuvering system according to  claim 12 , further comprising:
 a network to provide information communications in the watercraft maneuvering system; wherein   the predetermined mode selection criterion includes a criterion related to a communication state of the network.   
     
     
         17 . A watercraft comprising:
 a hull; and   the watercraft maneuvering system according to  claim 1  provided on the hull.   
     
     
         18 . A watercraft comprising:
 a hull; and   the watercraft maneuvering system according to  claim 8  provided on the hull.   
     
     
         19 . A watercraft comprising:
 a hull; and   the watercraft maneuvering system according to  claim 12  provided on the hull.