US-20260125143-A1 - JET PROPULSION BOAT THRUST CONTROL SYSTEM

US20260125143A1US 20260125143 A1US20260125143 A1US 20260125143A1US-20260125143-A1

Abstract

A jet propulsion boat includes: a boat body; a propulsion device that imparts propulsion force to the boat body to propel the boat body; an engine and an electric motor that drive the propulsion device; and a control device that determines which of an engine mode and an electric mode is to be used as an operation mode of driving the propulsion device in accordance with a condition, the engine mode configured to drive the propulsion device with the engine and the electric mode configured to drive the propulsion device with the electric motor while stopping the engine, and controls the engine and the electric motor to drive the propulsion device in the determined operation mode.

Inventors

Toshio Araki
Kazumasa Hisada
Daisuke Kawai
Shohei Terai
Takuya Sakamoto
Yoshihito Uchino

Assignees

KAWASAKI MOTORS, LTD.

Dates

Publication Date: 20260507
Application Date: 20260102

Claims (19)

1 . A jet propulsion boat comprising: a boat body; a propulsion device that imparts propulsion force to the boat body to propel the boat body; an engine and an electric motor that drive the propulsion device; and control circuitry configured to determine which of an engine mode and an electric mode is to be used as an operation mode of driving the propulsion device in accordance with a condition, the engine mode configured to drive the propulsion device with the engine and the electric mode configured to drive the propulsion device with the electric motor while stopping the engine, and controls the engine and the electric motor to drive the propulsion device in the determined operation mode, wherein the control circuitry determines the operation mode to be the electric mode when the boat body is requested to be maintained at a fixed position.
2 . The jet propulsion boat according to claim 1 , wherein the electric motor has maximum output smaller than maximum output of the engine.
3 . The jet propulsion boat according to claim 1 , wherein the propulsion device includes: a first propulsion device that is driven by the engine to impart propulsion force to the boat body, and a second propulsion device that is driven by the electric motor to impart propulsion force to the boat body, the propulsion force of the second propulsion device being different from the propulsion force imparted to the boat body by the first propulsion device.
4 . The jet propulsion boat according to claim 3 , wherein: the second propulsion device is to impart propulsion force to the boat body, the propulsion force being different in direction from the propulsion force of the first propulsion device.
5 . The jet propulsion boat according to claim 3 , wherein: the second propulsion device is to impart the propulsion force in each of a plurality of directions different from each other to the boat body.
6 . The jet propulsion boat according to claim 5 , wherein: the second propulsion device includes a plurality of thrusters that are each capable of imparting propulsion force different in direction to the boat body, and the control circuitry adjusts a traveling direction of the boat body by adjusting a magnitude of propulsion force of each of the plurality of thrusters when the propulsion device is driven in the electric mode.
7 . The jet propulsion boat according to claim 5 , wherein: the second propulsion device includes a plurality of thrusters that are each capable of imparting propulsion force different in direction to the boat body, and the control circuitry adjusts a posture of the boat body by adjusting a magnitude of propulsion force of each of the plurality of thrusters when the propulsion device is driven in the electric mode.
8 . The jet propulsion boat according to claim 1 , further comprising: a falling overboard detector configured to detect that a driver of the jet propulsion boat has fallen into the water, wherein the control circuitry determines the operation mode to be the electric mode when the falling overboard detector detects that the driver has fallen into the water.
9 . The jet propulsion boat according to claim 8 , further comprising: a falling overboard position detector configured to detect a falling overboard position of the driver, wherein when the falling overboard detector detects that the driver has fallen into the water, the control circuitry causes the boat body to navigate toward the falling overboard position of the driver detected by the falling overboard position detector in a state where the operation mode is set to the electric mode.
10 . The jet propulsion boat according to claim 1 , wherein: the control circuitry determines the operation mode to be the electric mode when the boat body is requested to be moved toward a target position.
11 . The jet propulsion boat according to claim 1 , wherein: the control circuitry determines the operation mode to be the electric mode when the boat body is requested to be changed in posture.
12 . The jet propulsion boat according to claim 1 , wherein: the control circuitry includes area determination circuitry configured to detect whether the boat body is located within a predetermined restriction area, and when the area determination circuitry determines that the boat body is located within the predetermined restriction area, the control circuitry determines the operation mode to be the electric mode.
13 . The jet propulsion boat according to claim 1 , further comprising: an operation interface to interface with a driver of the jet propulsion boat, wherein the control circuitry determines the operation mode to be the electric mode when a predetermined operation is performed on the operation interface.
14 . The jet propulsion boat according to claim 1 , further comprising: a battery mounted on the boat body to supply power to the electric motor; and a remaining battery capacity detector configured to detect remaining capacity of the battery, wherein the control circuitry prohibits switching from the engine mode to the electric mode when the remaining capacity of the battery detected by the remaining battery capacity detector is equal to or less than predetermined determination capacity.
15 . The jet propulsion boat according to claim 1 , further comprising: a display mounted on the boat body to display the operation mode that is switched from the engine mode to the electric mode.
16 . A jet propulsion boat comprising: a boat body; a propulsion device that imparts propulsion force to the boat body to propel the boat body; an engine and an electric motor that drive the propulsion device; and control circuitry configured to determine which of an engine mode and an electric mode is to be used as an operation mode of driving the propulsion device in accordance with a condition, the engine mode configured to drive the propulsion device with the engine and the electric mode configured to drive the propulsion device with the electric motor while stopping the engine, and controls the engine and the electric motor to drive the propulsion device in the determined operation mode, wherein the control circuitry determines the operation mode to be the electric mode when the boat body is requested to be moved toward a target position.
17 . A jet propulsion boat comprising: a boat body; a propulsion device that imparts propulsion force to the boat body to propel the boat body; an engine and an electric motor that drive the propulsion device; and control circuitry configured to determine which of an engine mode and an electric mode is to be used as an operation mode of driving the propulsion device in accordance with a condition, the engine mode configured to drive the propulsion device with the engine and the electric mode configured to drive the propulsion device with the electric motor while stopping the engine, and controls the engine and the electric motor to drive the propulsion device in the determined operation mode, wherein the control circuitry determines the operation mode to be the electric mode when the boat body is requested to be changed in posture.
18 . A jet propulsion boat comprising: a boat body; a propulsion device that imparts propulsion force to the boat body to propel the boat body; an engine and an electric motor that drive the propulsion device; control circuitry configured to determine which of an engine mode and an electric mode is to be used as an operation mode of driving the propulsion device in accordance with a condition, the engine mode configured to drive the propulsion device with the engine and the electric mode configured to drive the propulsion device with the electric motor while stopping the engine, and controls the engine and the electric motor to drive the propulsion device in the determined operation mode; and an operation interface to interface with a driver of the jet propulsion boat, wherein the control circuitry determines the operation mode to be the electric mode when a predetermined operation is performed on the operation interface.
19 . A jet propulsion boat comprising: a boat body; a propulsion device that imparts propulsion force to the boat body to propel the boat body; an engine and an electric motor that drive the propulsion device; control circuitry configured to determine which of an engine mode and an electric mode is to be used as an operation mode of driving the propulsion device in accordance with a condition, the engine mode configured to drive the propulsion device with the engine and the electric mode configured to drive the propulsion device with the electric motor while stopping the engine, and controls the engine and the electric motor to drive the propulsion device in the determined operation mode; a battery mounted on the boat body to supply power to the electric motor; and a remaining battery capacity detector configured to detect remaining capacity of the battery, wherein the control circuitry prohibits switching from the engine mode to the electric mode when the remaining capacity of the battery detected by the remaining battery capacity detector is equal to or less than predetermined determination capacity.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation of U.S. application Ser. No. 18/110,892, filled on Feb. 17, 2023, the entire disclosure of which are incorporated herein by reference. BACKGROUND Technical Field The present disclosure relates to a jet propulsion boat that moves on the water. Background Art Known types of a jet propulsion boat include a jet propulsion boat disclosed in US 2013/0102206 A1. To improve convenience of a jet propulsion boat, increase in a degree of freedom in operation is desirable. SUMMARY The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a jet propulsion boat that has a high degree of freedom in operation. To solve the above problem, a jet propulsion boat according to an aspect of the present disclosure includes a boat body, a propulsion device that imparts propulsion force to the boat body to propel the boat body, an engine and an electric motor that drive the propulsion device, and a control device that determines which of an engine mode and an electric mode is to be used as an operation mode of driving the propulsion device in accordance with a condition, the engine mode configured to drive the propulsion device with the engine and the electric mode configured to drive the propulsion device with the electric motor while stopping the engine, and controls the engine and the electric motor to drive the propulsion device in the determined operation mode. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially broken side view of a jet propulsion boat according to a first embodiment of the present disclosure; FIG. 2 is a plan view of the jet propulsion boat; FIG. 3 is a plan sectional view schematically illustrating structure of a second propulsion device of the jet propulsion boat; FIG. 4 is a perspective view illustrating an operation lever for operating the second propulsion device; FIG. 5 shows a relationship between a tilting direction of the operation lever and operation (traveling direction) of the jet propulsion boat in a table format; FIG. 6 is a functional block diagram illustrating a control system of a jet propulsion boat; FIG. 7 is a diagram illustrating an example of an image displayed on a display; and FIG. 8 is a flowchart illustrating contents of control related to mode switching performed by a control device. DETAILED DESCRIPTION Hereinafter, a jet propulsion boat according to an embodiment of the present disclosure will be described with reference to the drawings. Although some of the drawings indicate directions of front, rear, left, and right, these directions each align with a direction viewed from a driver on the jet propulsion boat. Configuration of Jet Propulsion Boat FIG. 1 is a partially broken side view of a jet propulsion boat 1 according to a first embodiment of the present disclosure, and FIG. 2 is a plan view of the jet propulsion boat 1. The jet propulsion boat 1 jets a water flow backward to move on the water in reaction to the water flow. The jet propulsion boat 1 according to the present embodiment is a straddle-type personal watercraft also called PWC. Thus, the jet propulsion boat 1 is abbreviated below as a PWC 1. The PWC 1 includes an engine 5 and an electric motor for driving a propulsion device that imparts propulsion force to a boat body 10. The PWC 1 in the present embodiment includes a plurality of electric motors 51, 61, 71 for driving the propulsion device. The propulsion device includes a first propulsion device 2, and a second propulsion device 3 that imparts propulsion force different from that of the first propulsion device 2 to the boat body 10. The first propulsion device 2 is an engine type propulsion device, and is driven by the engine 5. The second propulsion device 3 is an electric propulsion device, and is driven by electric motors 51, 61, and 71. The boat body 10 includes a hull 11 and a deck 12 overlying the hull 11. The deck 12 is provided with a handle 13, the seat 14, and a display 15. The handle 13 is a steering handle operated by the driver M for steering the PWC 1. The seat 14 allows a driver M who drives the PWC 1 to sit thereon. The seat 14 may be a seat on which at least the driver M can sit. That is, the seat 14 may be a multi-seat on which not only the driver M but also a fellow passenger can sit, or may be a single-seat on which only the driver M can sit. The display 15 displays various types of information regarding operation of the PWC 1, such as moving speed, a remaining amount of fuel, and an operation mode. The display 15 in the present embodiment is a touch panel type display that allows various input operations to be performed on the display 15. The display 15 corresponds to a “display unit” in the present disclosure. The first propulsion device 2 includes a jet pump 6 that is driven by the engine 5 and injects water, and a reverse bucket 7 (FIG. 1) disposed at an outlet part of the jet pump 6. The engi