Patent Description:
In a boat rental business, for instance, the followings are executed at the time of returning a rental watercraft: charging of fuel fee and checkup of a trouble or malfunction and so forth caused by a user operation.

The fuel fee is charged based on the amount of fuel required for filling up the watercraft after rental. However, a fill-up position varies with the tilt of the watercraft; hence, the fuel fee has a large margin of error. Besides, it is difficult to check whether or not the watercraft had been filled up at the start of rental. Regarding the trouble or malfunction and so forth, for instance, even when an undesired load has acted on an engine due to an unrecommended operation performed by the user during navigation, it is difficult to confirm occurrence of such a trouble unless the trouble is uncovered in a recognizable manner.

On the other hand, there is a type of watercraft including a communication device for performing wireless communication with a server. For example, <CIT> describes a watercraft including a communication device communicable with a server over the Internet. A controller in the watercraft transmits information related to the watercraft obtained during navigation to the server through the communication device.

Because of this, it can be assumed to transmit data related to an engine, including the flow rate of fuel, operations, and so forth, to the server through the communication device during navigation. However, it is concerned that the data are falsified and are then transmitted to the server.

The following content has been disclosed as a technology for inhibiting data falsification: a terminal transmits, to a server, information encrypted with an identification code assigned to the terminal; then, the server decrypts the information with the identification code assigned to the terminal as a sender (see e.g., <CIT>).

However, even if the technology described in <CIT> is used for transmitting information related to a watercraft to a server, it is made impossible to find falsification made for the information when the information per se has been falsified at the time of informational input into the terminal from an information source. Besides, even when encryption made for the information has not been cracked yet, false information can be transmitted to the server by recording data communication in advance and thereafter transmitting the recorded data to the server.

It is an object of the present invention to provide a marine propulsion device information transmitting and receiving system and a marine propulsion device information transmitting and receiving method, whereby data related to an engine of a watercraft can be inhibited from being falsified. According to the present invention said object is solved by a marine propulsion device information transmitting and receiving system having the features of independent claim <NUM>. Moreover, according to the present invention said object is solved by a marine propulsion device information transmitting and receiving method having the features of independent claim <NUM>. Preferred embodiments are laid down in the dependent claims.

A marine propulsion device information transmitting and receiving system according to an aspect includes a server and a watercraft. The watercraft includes a propulsion device and a communication device performing communication with the server. The propulsion device includes an engine and a controller that controls the engine and is connected to the communication device. The controller encrypts an operating time of the engine and data related to the engine with an encryption key associated with information unique to the engine. The communication device transmits the information unique to the engine, the encrypted operating time of the engine, and the encrypted data related to the engine to the server. The server receives the information unique to the engine, the encrypted operating time of the engine, and the encrypted data related to the engine, decrypts the encrypted operating time of the engine and the encrypted data related to the engine with the encryption key associated with the information unique to the engine, and determines whether or not the decrypted data related to the engine are genuine based on the decrypted operating time of the engine.

A marine propulsion device information transmitting and receiving method according to another aspect is a method of transmitting and receiving data related to an engine of a propulsion device installed in a watercraft. The marine propulsion device information transmitting and receiving method includes encrypting the data related to the engine of the propulsion device and an operating time of the engine with an encryption key associated with information unique to the engine, transmitting the information unique to the engine, the encrypted data related to the engine, and the encrypted operating time of the engine through a communication device, receiving the information unique to the engine, the encrypted data related to the engine, and the encrypted operating time of the engine by a server, and decrypting the encrypted data related to the engine and the encrypted operating time of the engine with the encryption key associated with the information unique to the engine and determining whether or not the decrypted data related to the engine are genuine based on the decrypted operating time of the engine.

A marine propulsion device information transmitting and receiving system according to yet another aspect includes a server and a watercraft. The watercraft includes a propulsion device and a communication device performing communication with the server. The propulsion device includes an engine and a controller that controls the engine and is connected to the communication device. The controller encrypts data related to the engine with an encryption key. The communication device transmits the encrypted data related to the engine to the server. The server decrypts the encrypted data related to the engine with the encryption key.

The data related to the engine are encrypted with the encryption key and are then transmitted to the server, whereby such a situation can be inhibited that false data are inputted into the communication device and are then transmitted to the server. The operating time of the engine is transmitted together with the data related to the engine; hence, it is possible to determine whether or not the data related to the engine are genuine based on the operating time of the engine. Because of this, even when the engine is operated in an arbitrary operating state; then, data outputted from the engine at this point of time are stored for a predetermined period of time, are then transmitted to the communication device, and are further transmitted therefrom as false data to the server, it is possible to determine that the data received by the server correspond to the stored data with reference to the operating time of the engine. With the configuration, it is possible to prevent the data related to the engine from being falsified.

A preferred embodiment will be hereinafter explained with reference to drawings.

<FIG> is a diagram showing a marine propulsion device information transmitting and receiving system <NUM> according to the preferred embodiment. The marine propulsion device information transmitting and receiving system <NUM> includes a watercraft <NUM> and a cloud server <NUM> (exemplary server). The watercraft <NUM> transmits data (information) related to an engine of a marine propulsion device <NUM> (exemplary propulsion device) to the cloud server <NUM>; then, the cloud server <NUM> receives the data related to the engine and determines whether or not the received data is genuine. The watercraft <NUM> includes a vessel body <NUM>, the marine propulsion device <NUM>, and a DCM (Data Communication Module) <NUM>. The data related to the engine of the marine propulsion device <NUM> are outputted to the DCM <NUM>. The DCM <NUM> performs wireless communication with the cloud server <NUM>.

The marine propulsion device <NUM> is attached to the stern of the vessel body <NUM>. The marine propulsion device <NUM> generates a thrust for propelling the watercraft <NUM>. In the present preferred embodiment, the marine propulsion device <NUM> is an outboard motor. <FIG> is a side view of the marine propulsion device <NUM>.

The marine propulsion device <NUM> includes an upper casing <NUM>, a lower casing <NUM>, an exhaust guide section <NUM>, and an engine <NUM>. The upper casing <NUM>, the lower casing <NUM>, and the engine <NUM> are fixed to the exhaust guide section <NUM>.

The engine <NUM> is disposed inside the upper casing <NUM>. The engine <NUM> includes a crankshaft <NUM>. A drive shaft <NUM> is disposed inside the lower casing <NUM>. The drive shaft <NUM> is disposed along an up-and-down direction inside the lower casing <NUM>. The drive shaft <NUM> is coupled to the crankshaft <NUM> of the engine <NUM>. A propeller <NUM> is disposed at a lower portion of the lower casing <NUM>. The propeller <NUM> is disposed below the engine <NUM>. A propeller shaft <NUM> is coupled to the propeller <NUM>. The propeller shaft <NUM> is disposed along a back-and-forth direction. The propeller shaft <NUM> is coupled to a lower portion of the drive shaft <NUM> through a forward/rearward moving switch section <NUM>.

Diagrams (a) and (b) in <FIG> are closeup views of the forward/rearward moving switch section <NUM> shown in <FIG> and the vicinity thereof. The forward/rearward moving switch section <NUM> includes a pinion gear <NUM>, a forward moving gear <NUM>, a rearward moving gear <NUM>, and a dog clutch <NUM>. The pinion gear <NUM> is coupled to the drive shaft <NUM>. The pinion gear <NUM> is meshed with the forward moving gear <NUM> and the rearward moving gear <NUM>. The forward moving gear <NUM> and the rearward moving gear <NUM> are provided to be rotatable relative to the propeller shaft <NUM>. The dog clutch <NUM> is attached to the propeller shaft <NUM>, while being non-rotatable relative thereto. Besides, the dog clutch <NUM> is provided to be movable to a forward moving position, a rearward moving position, and a neutral position along the axial direction of the propeller shaft <NUM>. The dog clutch <NUM> is moved to the forward moving position, the rearward moving position, and the neutral position by a shift actuator <NUM> (to be described). When the dog clutch <NUM> is located in the forward moving position shown in the diagram (a) of <FIG>, the forward moving gear <NUM> and the propeller shaft <NUM> are fixed by the dog clutch <NUM>, while being non-rotatable relative to each other. In this case, rotation of the drive shaft <NUM> is transmitted to the propeller shaft <NUM> through the forward moving gear <NUM>. In other words, the forward/rearward moving switch section <NUM> is set to a forward moving state in which rotation of the drive shaft <NUM> is transmitted to the propeller <NUM> so as to rotate the propeller <NUM> in a direction corresponding to forward movement. Accordingly, the propeller <NUM> is rotated in the direction corresponding to the forward movement of the vessel body <NUM>. On the other hand, when the dog clutch <NUM> is located in the rearward moving position shown in the diagram (b) of <FIG>, the rearward moving gear <NUM> and the propeller shaft <NUM> are fixed by the dog clutch <NUM>, while being non-rotatable relative to each other. In this case, rotation of the drive shaft <NUM> is transmitted to the propeller shaft <NUM> through the rearward moving gear <NUM>. In other words, the forward/rearward moving switch section <NUM> is set to a rearward moving state in which rotation of the drive shaft <NUM> is transmitted to the propeller <NUM> so as to rotate the propeller <NUM> in a direction corresponding to rearward movement. Accordingly, the propeller <NUM> is rotated in the direction corresponding to the rearward movement of the vessel body <NUM>. When the dog clutch <NUM> is located in the neutral position between the forward moving position and the rearward moving position, each of the forward moving gear <NUM> and the rearward moving gear <NUM> is made rotatable relative to the propeller shaft <NUM>. In other words, rotation of the drive shaft <NUM> is not transmitted to the propeller shaft <NUM>; hence, the propeller shaft <NUM> is enabled to idle.

In the marine propulsion device <NUM>, a driving force generated by the engine <NUM> is transmitted to the propeller <NUM> through the drive shaft <NUM> and the propeller shaft <NUM>. Accordingly, the propeller <NUM> is rotated in either the direction corresponding to forward movement or the direction corresponding to rearward movement. As a result, a thrust is generated to move forward or rearward the watercraft <NUM> to which the marine propulsion device <NUM> is attached.

Besides, as shown in <FIG>, the marine propulsion device <NUM> is provided with an exhaust pathway <NUM> in the interior thereof. The exhaust pathway <NUM> extends downward from the engine <NUM>. The exhaust pathway <NUM> is connected to an exhaust port of the engine <NUM> and, as shown in <FIG>, is communicated with the internal space of a propeller boss 33a of the propeller <NUM>. The exhaust gas from the engine <NUM> passes through the exhaust pathway <NUM> and is then discharged through the internal space of the propeller boss 33a into the water.

<FIG> is a schematic top view of an internal configuration of the engine <NUM>. In the present preferred embodiment, the engine <NUM> includes a crankcase <NUM> and a plurality of cylinders <NUM>; however, the number and the layout of the cylinders <NUM> may be set arbitrarily. The configuration of one cylinder <NUM> among the plural cylinders <NUM> of the engine <NUM> will be hereinafter explained based on <FIG>; however, all the plural cylinders <NUM> of the engine <NUM> have a similar configuration to the cylinder <NUM> shown in <FIG>. The cylinder <NUM> includes a cylinder head <NUM> and a cylinder block <NUM>. The cylinder head <NUM> is attached to the cylinder block <NUM>. The cylinder block <NUM> is provided with a cylinder chamber <NUM> in the interior thereof. A piston <NUM> is disposed inside the cylinder chamber <NUM>, while being movable in the axial direction of the cylinder chamber <NUM>. A connecting rod <NUM> is coupled at one end thereof to the piston <NUM>. The connecting rod <NUM> is coupled at the other end thereof to the crankshaft <NUM>.

The cylinder head <NUM> includes an intake port <NUM>, an exhaust port <NUM>, and a combustion chamber <NUM>. Each of the intake port <NUM> and the exhaust port <NUM> is communicated with the combustion chamber <NUM>. The intake port <NUM> is opened and closed by an intake valve <NUM>. The exhaust port <NUM> is opened and closed by an exhaust valve <NUM>. An intake pipe <NUM> is connected to the intake port <NUM>. A fuel injection device <NUM> is attached to the intake pipe <NUM>. The fuel injection device <NUM> injects a fuel to be supplied to the combustion chamber <NUM>. Besides, a throttle valve <NUM> is disposed in the intake pipe <NUM>. The amount of mixture gas to be fed to the combustion chamber <NUM> is configured to be regulated by changing the opening degree of the throttle valve <NUM>. An exhaust pipe <NUM> is connected to the exhaust port <NUM>. Besides, an ignition device <NUM> is attached to the cylinder head <NUM>. The ignition device <NUM> is inserted into the combustion chamber <NUM> and ignites the fuel.

The intake valve <NUM> is biased in a direction corresponding to closing the intake port <NUM> by an urging member such as a coil spring or so forth (not shown in the drawings). The intake valve <NUM> is opened and closed when an intake camshaft <NUM> is driven to be rotated. The exhaust valve <NUM> is biased in a direction corresponding to closing the exhaust port <NUM> by an urging member such as a coil spring or so forth (not shown in the drawings). The exhaust valve <NUM> is opened and closed when an exhaust camshaft <NUM> is driven to be rotated.

<FIG> is a top view of a drive mechanism for driving the intake camshaft <NUM> and the exhaust camshaft <NUM> to be rotated. The drive mechanism is disposed on, for instance, the top surface of the engine <NUM>. As shown in <FIG>, an intake cam pulley <NUM> is fixed to an end of the intake camshaft <NUM>. An exhaust cam pulley <NUM> is fixed to an end of the exhaust camshaft <NUM>. Besides, a crank pulley <NUM> is fixed to the crankshaft <NUM>. Moreover, a cam belt <NUM> is wrapped and stretched over the intake cam pulley <NUM>, the exhaust cam pulley <NUM>, the crank pulley <NUM>, and a plurality of intermediate pulleys 66a, 66b, and 66c. The driving force of the crankshaft <NUM> is transmitted to the intake camshaft <NUM> and the exhaust camshaft <NUM> through the cam belt <NUM>. It should be noted that a flywheel <NUM> is fixed to an end of the crankshaft <NUM>.

<FIG> is a schematic diagram of a configuration of a control system of the engine <NUM>. The engine <NUM> is controlled by an ECU (Engine Control Unit) <NUM>. An operating device <NUM> and a variety of sensors <NUM> to <NUM> for detecting a variety of information related to the engine <NUM> are connected to the ECU <NUM> (exemplary controller).

The operating device <NUM> includes a throttle operating device <NUM>, a shift operating device <NUM>, and a start/stop operating device <NUM> for operating start and stop of the engine <NUM>. The throttle operating device <NUM> includes, for instance, a throttle operating member 73a such as a throttle lever. The throttle operating device <NUM> inputs an operating signal for controlling an output of the engine <NUM> to the ECU <NUM> in accordance with an operation of the throttle operating member 73a. The shift operating device <NUM> includes, for instance, a shift operating member 74a such as a shift lever. The shift operating device <NUM> inputs an operating signal for switching forward movement and rearward movement of the watercraft <NUM> to the ECU <NUM> in accordance with an operation of the shift operating member 74a. Specifically, the shift operating member 74a is operable to any one of shift positions composed of a forward moving position, a rearward moving position, and a neutral position. An operating signal, corresponding to one selected from the shift position, is inputted the ECU <NUM>. The start/stop operating device <NUM> for operating start and stop of the engine <NUM> is, for instance, a key switch and inputs an operating signal for starting or stopping the engine <NUM> to the ECU <NUM>.

The sensors <NUM> to <NUM>, connected to the ECU <NUM>, are specifically composed of a crank angle sensor <NUM> (exemplary rotational speed sensor), a cam angle sensor <NUM>, a throttle opening degree sensor <NUM>, an intake pressure sensor <NUM>, an exhaust pressure sensor <NUM>, and a shift position sensor <NUM>. The crank angle sensor <NUM> detects the angle of rotation of the crankshaft <NUM>. The cam angle sensor <NUM> detects the angle of rotation of the exhaust camshaft <NUM>. The throttle opening degree sensor <NUM> detects the opening degree of the throttle valve <NUM>. The intake pressure sensor <NUM> detects the pressure inside the intake pipe <NUM>. The exhaust pressure sensor <NUM> detects the pressure inside the exhaust pipe <NUM>. The shift position sensor <NUM> detects to which of the shift states the forward/rearward moving switch section <NUM> is set among the forward moving state, the rearward moving state, and the neutral state. The shift position sensor <NUM> detects the shift state of the forward/rearward moving switch section <NUM> by detecting, for instance, the position of the dog clutch <NUM> described above. Each of the sensors inputs a detection signal to the ECU <NUM>.

The ECU <NUM> includes a recording section <NUM>, a CPU (Central Processing Unit) <NUM>, and an externally outputting section <NUM>. The recording section <NUM> is a recording device that electronic data are writable therein and are readable therefrom. The recording section <NUM> includes a memory such as a RAM (Random Access Memory) or a ROM (Read Only Memory) and an auxiliary storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The recording section <NUM> stores control programs corresponding to predetermined operating states.

The recording section <NUM> records the detection signals outputted from the sensors <NUM> to <NUM>. The recording section <NUM> records a serial number D1 of the engine <NUM> and an encryption key associated with the serial number D1 of the engine <NUM>. The engine serial number and the encryption key associated therewith are written in the ECU <NUM> in manufacture of the engine <NUM>. It should be noted that the information, with which the encryption key is associated, may not be limited to the engine serial number and is not particularly limited to specific information as long as the information is unique to the engine.

The recording section <NUM> records an operating time of the engine <NUM> (engine operating time D2) and information related to the engine <NUM> (engine related data D3). The engine operating time D2 is a cumulative operating time of the engine <NUM> since manufacture of the engine <NUM>. The recording section <NUM> stores the cumulative engine operating time inputted thereto through the CPU <NUM> at predetermined intervals of time.

The engine related data D3 is a type of data for which falsification can be possibly made. The engine related data D3 includes the flow rate of fuel, information related to contact of an object against the propeller, or information related to reverse rotation.

The CPU <NUM>, which is a processor, determines the present operating state based on the signals inputted thereto from the variety of sensors <NUM> to <NUM> and the operating device <NUM>. Under the control program corresponding to the present operating state, the CPU <NUM> controls actions of the ignition device <NUM>, the fuel injection device <NUM>, and the throttle valve <NUM>. Besides, the ECU <NUM> controls the shift actuator <NUM> based on the operating signal inputted thereto from the shift operating device <NUM>. The shift actuator <NUM> includes, for instance, drive means such as a motor. The shift actuator <NUM> is controlled by the ECU <NUM> to move the dog clutch <NUM> described above to any one of the forward moving position, the rearward moving position, and the neutral position.

The CPU <NUM> obtains the flow rate of fuel by cumulating the amount of fuel injected by the fuel injection device <NUM> and records the obtained flow rate of fuel in the recording section <NUM>. Data related to the flow rate of used fuel are recorded in the recording section <NUM>.

The CPU <NUM> determines whether or not the crankshaft <NUM> has been reversely rotated based on the detection signals recorded in the recording section <NUM>, i.e., the detection signals inputted thereto from the crank angle sensor <NUM> and the cam angle sensor <NUM>. Chances are that in occurrence of the reverse rotation of the crankshaft <NUM>, water intrudes into the engine <NUM> through the exhaust pathway <NUM> shown in <FIG>.

The reverse rotation of the crankshaft <NUM> is detected by, for instance, such a heretofore known method as disclosed in <CIT>. Specifically, the reverse rotation of the crankshaft <NUM> is detected by the detection signals outputted from the crank angle sensor <NUM> and the cam angle sensor <NUM>. In other words, the crank angle sensor <NUM> and the cam angle sensor <NUM> correspond to a reverse rotation detector for detecting the reverse rotation of the crankshaft <NUM> in the present invention. A series of processing executed by the CPU <NUM> for detecting the reverse rotation of the crankshaft <NUM> will be hereinafter explained.

The crank angle sensor <NUM> is a magnetic sensor, and as shown in <FIG>, detects passage of a plurality of protrusions 32a of the crankshaft <NUM>. It should be noted that in <FIG>, reference sign 32a is assigned to only portion of the plural protrusions 32a. The crankshaft <NUM> is provided with the plural protrusions 32a regularly aligned on the surface thereof. It should be noted that the crankshaft <NUM> is provided with a missing region 32b on the surface thereof. The protrusions 32a are not provided in the missing region 32b and the interval between a pair of adjacent protrusions 32a defining the missing region 32b is different from that between each other pair of adjacent protrusions 32a.

The cam angle sensor <NUM> is a magnetic sensor and detects passage of a plurality of protrusions 62a provided on the exhaust camshaft <NUM>. It should be noted that in <FIG>, reference sign 62a is assigned to only portion of the plural protrusions 62a. The exhaust camshaft <NUM> is provided with the plural protrusions 62a regularly aligned on the surface thereof. It should be noted that the exhaust camshaft <NUM> is provided with a missing region 62b on the surface thereof. The protrusions 62a are not provided in the missing region 62b and the interval between a pair of adjacent protrusions 62a defining the missing region 62b is different from that between each other pair of adjacent protrusions 62a. When the engine <NUM> is started, the crankshaft <NUM>, the intake camshaft <NUM>, and the exhaust camshaft <NUM> are driven. Accordingly, the crank angle sensor <NUM> detects passage of the protrusions 32a of the crankshaft <NUM>. On the other hand, the cam angle sensor <NUM> detects passage of the protrusions 62a of the exhaust camshaft <NUM>. The crank angle sensor <NUM> and the cam angle sensor <NUM> transmit the detection signals to the ECU <NUM>.

Now, a magnetic field is strengthened when the protrusions 62a pass through a position opposed to the crank angle sensor <NUM>; hence, periodic spikes are formed in the waveform of the detection signal. By contrast, when the missing region 62b passes through the position opposed to the crank angle sensor <NUM>, such spikes are not formed in the waveform of the detection signal and the signal strength of the detection signal is kept constant. Because of this, crank spike regions, in each of which the periodic spikes are formed, and crank flat regions, in each of which the periodic spikes are not formed and the signal strength is kept constant (i.e., the waveform is flat), alternately appear in the waveform of the detection signal of the crank angle sensor <NUM>. As a result of detecting these regions, the speed of rotation and the angle of rotation of the crankshaft <NUM> are detected. Likewise, cam spike regions, in each of which the periodic spikes continue due to passage of the protrusions 62a, and cam flat regions, in each of which a flat waveform continues due to passage of the missing region 62b, alternately appear in the waveform of the detection signal of the cam angle sensor <NUM>. As a result of detecting these regions, the speed of rotation and the angle of rotation of the exhaust camshaft <NUM> are detected.

As described above, the crankshaft <NUM> and the exhaust camshaft <NUM> are rotated in conjunction with each other; hence, when the crankshaft <NUM> is rotated forwardly (i.e., in a normal rotational direction), the crank spike regions and the cam spike regions appear in conjunction at identical timing.

Contrarily, when the crankshaft <NUM> is rotated reversely (i.e., in a direction opposite to the normal rotational direction), the timing at which the cam spike regions are detected are made different from that in forward rotation of the crankshaft <NUM>. Because of this, the periods at which the crank spike regions and the cam spike regions are detected are made different from those in the forward rotation of the crankshaft <NUM>. When the crank spike regions and the cam spike regions are detected at periods different from those in the forward rotation of the crankshaft <NUM>, the CPU <NUM> determines that reverse rotation of the crankshaft <NUM> has occurred.

When determining that reverse rotation of the crankshaft <NUM> has occurred, the CPU <NUM> records the information in the recording section <NUM> as information related to reverse rotation.

The CPU <NUM> determines whether or not the propeller <NUM> has been contacted (hit) by an object based on the detection signal of the crank angle sensor <NUM>, which has been recorded in the recording section <NUM>. The ECU <NUM> is enabled to determine the speed of rotation of the propeller <NUM> based on the detection signal of the crank angle sensor <NUM>. Specifically, the speed of rotation of the propeller <NUM> is recorded at intervals of <NUM>, for instance, and the CPU <NUM> determines that the propeller <NUM> has been contacted by an object when the speed of rotation of the propeller <NUM> has reduced for <NUM> to an extent unlikely to occur in sudden deceleration normally assumed. A threshold for determining the above can be arbitrarily set based on the horsepower of the marine propulsion device <NUM> or so forth. When determining that the propeller <NUM> has been contacted by an object, the CPU <NUM> records the result of determination in the recording section <NUM> as information related to contact of an object against the propeller (information related to hitting of the propeller).

Alternatively, the CPU <NUM> may determine whether or not the propeller <NUM> has been contacted by an object based on the detection signal of the intake pressure sensor <NUM> and that of the crank angle sensor <NUM>, both of which have been recorded in the recording section <NUM>. The CPU <NUM> is enabled to determine a throttle state based on the detection signal of the intake pressure sensor <NUM>. The ECU <NUM> is enabled to determine the speed of rotation of the propeller <NUM> based on the detection signal of the crank angle sensor <NUM>. Thus, when it is specifically detected that the speed of rotation of the propeller <NUM> has reduced abruptly and then has increased while the throttle state has been kept constant, the CPU <NUM> determines that the propeller <NUM> has been contacted by an object. A threshold for determining the above can be arbitrarily set based on the horsepower of the marine propulsion device <NUM> or so forth. When determining that the propeller <NUM> has been contacted by an object, the CPU <NUM> records the result of determination in the recording section <NUM> as the information related to contact of an object against the propeller (information related to hitting of the propeller).

As described above, the flow rate of fuel, the information related to reverse rotation, or the information related to contact of an object against the propeller can be included in the engine related data D3.

The ECU <NUM> encrypts the engine operating time D2 and the engine related data D3 with the encryption key associated with the engine serial number D1. The ECU <NUM> outputs the serial number D1, the encrypted engine operating time D2, and the encrypted engine related data D3 to the DCM <NUM> through the externally outputting section <NUM>.

The externally outputting section <NUM> is an interface for performing electronic data communication with the DCM <NUM>. The externally outputting section <NUM> transmits the serial number D1, the encrypted engine operating time D2, and the encrypted engine related data D3 to the DCM <NUM>.

The DCM <NUM> is disposed in the watercraft <NUM> and is connected to the ECU <NUM>. As shown in <FIG>, the DCM <NUM> includes a GPS (Global Positioning System) module <NUM>, a recording section <NUM>, a CPU (Central Processing Unit) <NUM>, and a cellular module <NUM>. The GPS module <NUM> receives a GPS signal from a GPS satellite and outputs positional information D4 of the watercraft <NUM> to the CPU <NUM>. The recording section <NUM> includes a memory such as a RAM (Random Access Memory) or a ROM (Read Only Memory) and an auxiliary storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The recording section <NUM> stores control programs corresponding to predetermined operating states.

The CPU <NUM>, which is a processor, operates under the control programs stored in the recording section <NUM>. The CPU <NUM> records the serial number D1, the encrypted engine operating time D2, and the encrypted engine related data D3, all of which are inputted thereto from the ECU <NUM>, in the recording section <NUM>.

The CPU <NUM> records the positional information D4, inputted thereto from the GPS module <NUM>, in the recording section <NUM>. The CPU <NUM> may record the positional information D4, inputted thereto from the GPS module <NUM>, in the recording section <NUM>, while associating the positional information D4 with the serial number D1, the encrypted engine operating time D2, and the encrypted engine related data D3, all of which have been received at a clock time that the positional information D4 has been received.

The CPU <NUM> transmits the serial number D1, the encrypted engine operating time D2, the encrypted engine related data D3, and the positional information D4, all of which have been recorded in the recording section <NUM>, to the cloud server <NUM> through the cellular module <NUM> at predetermined intervals of time. Data are outputted from the ECU <NUM> to the DCM <NUM> every several minutes and are recorded in the recording section <NUM>; then, data are transmitted from the DCM <NUM> to the cloud server <NUM> every several minutes or every several hours. Likewise, the positional information D4 outputted from the GPS module <NUM> may be recorded in the recording section <NUM> every several minutes.

Specifically, data may be outputted from the ECU <NUM> to the DCM <NUM> every one minute and may be recorded in the recording section <NUM>; then, data may be transmitted from the DCM <NUM> to the cloud server <NUM> every <NUM> minutes. In the case described above, a plurality of data sets recorded in the recording section <NUM> are collectively transmitted to the cloud server <NUM>. Likewise, regarding the positional information D4, a plurality of data sets may be recorded in the recording section <NUM>: then, the plurality of data sets of positional information D4 may be collectively transmitted from the DCM <NUM> to the cloud server <NUM>.

It should be noted that a time stamp may be applied to each of the plurality of data sets to be transmitted to the cloud server <NUM>. When the ECU <NUM> obtains either the engine operating time D2 or the engine related data D3, a time stamp may be applied to the obtained one D2, D3. The ECU <NUM> may encrypt the time stamp together with the engine operating time D2 and the engine related data D3. Besides, clock time information, included in the data received by the GPS module <NUM>, may be used as the time stamp for the positional information D4; alternatively, the DCM <NUM> may apply a time stamp to the positional information D4.

The cellular module <NUM> is communicable with the cloud server <NUM> through a mobile communication network. The mobile communication network is, for instance, a network of a <NUM>, <NUM>, or <NUM> mobile communication system.

The cloud server <NUM> receives the serial number D1, the encrypted engine operating time D2, the encrypted engine related data D3, and the positional information D4 from the DCM <NUM>. The cloud server <NUM> stores a plurality of engine serial numbers and a plurality of encryption keys associated with the engine serial numbers on a one-to-one basis as a plurality of pairs of engine serial number and encryption key. The cloud server <NUM> decrypts the encrypted engine operating time D2 and the encrypted engine related data D3 with the encryption key associated with the received serial number D1.

The cloud server <NUM> determines whether or not the decrypted engine related data D3 are genuine based on the decrypted engine operating time D2. The cloud server <NUM> determines whether or not the data D3 have been falsified.

Specifically, the cloud server <NUM> determines whether or not the engine related data D3 are genuine based on whether or not the engine operating time D2 has increased with elapse of time. For example, a time stamp has been applied to the engine operating time D2; hence, the cloud server <NUM> is enabled to determine that the engine related data D3 are not genuine, for instance, when the engine operating time D2 at a predetermined clock time is lesser than that at a clock time earlier than the predetermined clock time. Alternatively, the cloud server <NUM> is enabled to determine that the engine related data D3 are not genuine, for instance, when the engine operating time D2 received presently by the cloud server <NUM> is lesser than that received previously by the cloud server <NUM>. When the cloud server <NUM> collectively receives a plurality of data sets of the engine operating time D2, for instance, comparison can be made between one of the plurality of data sets of the engine operating time D2 received presently by the cloud server <NUM> and another of those received previously by the cloud server <NUM>. With the configuration, it is possible to prevent a type of falsification that data outputted from the ECU <NUM> have been recorded in advance and thereafter the recorded data are outputted to the DCM <NUM>.

Incidentally, when the engine related data D3 include the flow rate of fuel, the cloud server <NUM> is enabled to determine whether or not the engine related data D3 are genuine based on whether or not the operating time has increased in accordance with the used amount of fuel. For example, when a difference between a presently received operating time and a previously received operating time is large in comparison with the used amount of fuel calculated from a difference between a presently received flow rate of fuel and a previously received flow rate of fuel, it is possible to determine that the operating time is long with respect to the used amount of fuel; hence, the cloud server <NUM> is enabled to determine that the engine related data D3 are not genuine. With the configuration, it is possible to prevent a type of falsification that data outputted from the ECU <NUM> have been recorded in traveling at a low speed with a lesser used amount of fuel and thereafter the recorded data are outputted to the DCM <NUM>.

The cloud server <NUM> is enabled to determine that a misconduct has been done in the following situation: the cloud server <NUM> has received the positional information D4 but has not received yet the encrypted engine operating time D2 and the encrypted engine related data D3 even though the positional information has been changed. For example, the misconduct can be exemplified by cutting/disconnecting of a wiring for connection between the DCM <NUM> and the ECU <NUM>. When cutting/disconnecting of the wiring between the DCM <NUM> and ECU <NUM> is thus done as the misconduct, the positional information D4 detected by the DCM <NUM> becomes the only data to be transmitted to the cloud server <NUM>; hence, the misconduct can be detected based on the reasoning.

The cloud server <NUM> may receive unencrypted engine related data D3 together with the serial number D1, the encrypted engine operating time D2, and the encrypted engine related data D3 from the DCM <NUM>. In this case, the cloud server <NUM> may compare the unencrypted engine related data D3 and the decrypted engine related data D3 and may determine that the engine related data D3 are genuine when the unencrypted engine related data D3 and the decrypted engine related data D3 are matched. With the configuration, it is possible to confirm whether or not data decryption has been made correctly. Even when data decryption succeeds albeit a false encryption key is used for the data decryption, the following can be prevented: whether or not data are genuine is erroneously determined based on the data decrypted with the false encryption key. It should be noted that when the unencrypted engine related data D3 are transmitted to the cloud server <NUM>, the ECU <NUM> transmits the unencrypted engine related data D3 to the DCM <NUM>; then, the DCM <NUM> records the unencrypted engine related data D3 in the recording section <NUM>.

Next, a marine propulsion device information transmitting and receiving method according to the present preferred embodiment will be explained. <FIG> is a flowchart showing a marine propulsion device information transmitting and receiving method according to the present preferred embodiment.

In step S1, the CPU <NUM> in the ECU <NUM> encrypts the engine operating time D2 and the engine related data D3 with the encryption key associated with the serial number of the engine <NUM>. The encryption key has been recorded in the recording section <NUM> in advance.

In step S2, the serial number D1, the encrypted engine operating time D2, and encrypted engine related data D3 are outputted from the ECU <NUM> to the DCM <NUM>.

In step S3, the serial number D1, the encrypted engine operating time D2, and the encrypted engine related data D3 are inputted to the DCM <NUM>; then, the DCM <NUM> records the data D1, D2, and D3 in the recording section <NUM>.

In parallel with steps S1 to S3 described above, the GPS module <NUM> in the DCM <NUM> receives the positional information D4 from the GPS satellite in step S4. Then, in step S5, the positional information D4 is recorded in the recording section <NUM> in the DCM <NUM>.

In step S6, the DCM <NUM> determines whether or not a predetermined period of time has elapsed. The control flow in steps S1 to S3 and that in steps S4 and S5 are repeated respectively until the predetermined period of time elapses. With repetition of steps S1 to S3, a triad of data, composed of the serial number D1, the encrypted engine operating time D2, and the encrypted engine related data D3, is recorded in the recording section <NUM> in the DCM <NUM> a plurality of times in a time-series manner as a plurality of triads of data sets. Besides, with repetition of steps S4 and S5, the positional information D4 is recorded in the recording section <NUM> in the DCM <NUM> a plurality of times in a time-series manner as a plurality of data sets. The encrypted engine operating time D2 and the encrypted engine related data D3 may be obtained at intervals of time equal to or different from those at which the positional information D4 is obtained. Besides, when a clock time, at which the encrypted engine operating time D2 and the encrypted engine related data D3 have been obtained, and a clock time, at which the positional information D4 has been obtained, fall in a predetermined range of clock time, the CPU <NUM> may record the encrypted engine operating time D2, the encrypted engine related data D3, and the positional information D4 in the recording section <NUM>, while both the encrypted engine operating time D2 and the encrypted engine related data D3 are associated with the positional information D4.

In step S7, the DCM <NUM> transmits the serial number D1, the encrypted engine operating time D2, the encrypted engine related data D3, and the positional information D4 to the cloud server <NUM>.

In step S8, the cloud server <NUM> receives the serial number D1, the encrypted engine operating time D2, the encrypted engine related data D3, and the positional information D4.

In step S9, the cloud server <NUM> decrypts the encrypted engine operating time D2 and the encrypted engine related data D3 with the encryption key associated with the serial number D1.

In step S10, the cloud server <NUM> determines whether or not the decrypted engine related data D3 are genuine based on the decrypted engine operating time D2; then, the control steps end.

It should be noted that, when determining that the engine related data D3 are not genuine, the cloud server <NUM> may record the watercraft <NUM> relevant to the engine related data D3 and may specify a user who has used the watercraft <NUM>. Besides or alternatively, when determining that the engine related data D3 are not genuine, the cloud server <NUM> may transmit a signal for warning to the DCM <NUM> so as to display a warning on a monitor or so forth installed in the watercraft <NUM>.

The marine propulsion device information transmitting and receiving system <NUM> according to the present preferred embodiment has the following features.

The engine related data D3 are encrypted with the encryption key and are then transmitted to the cloud server <NUM>, whereby such a situation can be inhibited that false data are inputted into the DCM <NUM> and are then transmitted to the server. The engine operating time D2 is transmitted together with the engine related data D3; hence, it is possible to determine whether or not the engine related data D3 are genuine based on the operating time. Because of this, even when the engine is operated in an arbitrary operating state; then, data outputted from the engine at this point of time are stored for a predetermined period of time, are then transmitted to a communication device, and are further transmitted therefrom as false data to the server, it is possible to determine that the data received by the server correspond to the stored data with reference to the operating time. With the configuration, it is possible to prevent the engine related data from being falsified.

The ECU <NUM> obtains the flow rate of fuel to be supplied to the engine <NUM>. The engine related data D3 include the flow rate of fuel. With the configuration, it is possible to determine whether or not data of the flow rate of fuel transmitted to the cloud server <NUM> are genuine.

The cloud server <NUM> determines whether or not the engine related data D3 are genuine based on increase in the engine operating time D2. For example, in boat rental or so forth, when the engine operating time D2 is too short in comparison with a rental time, occurrence of a trouble or data falsification can be suspected.

When the engine operating time D2 at predetermined timing is lesser than that at earlier timing than the predetermined timing, the cloud server <NUM> determines that the engine related data D3 are not genuine. The engine operating time is defined as a cumulative operating time counted since manufacture of the engine; hence, when the operating time becomes lesser, it is possible to determine that the following type of data falsification has been made: the data, outputted from the ECU <NUM>, have been recorded previously and are thereafter inputted into the DCM <NUM>.

The cloud server <NUM> determines whether or not the engine related data D3 are genuine based on whether or not the engine operating time D2 has increased with increase in used amount of fuel detected based on the flow rate of fuel. With the configuration, it is possible to determine that the engine related data D3 are not genuine when the operating time has not appropriately increased with increase in used amount of fuel.

The DCM <NUM> transmits not only the serial number D1, the encrypted engine operating time D2, and the encrypted engine related data D3 but also the unencrypted engine related data to the cloud server <NUM>. The cloud server <NUM> compares the decrypted engine related data D3 and the unencrypted engine related data; then, when the compared data are matched, the cloud server <NUM> determines that the engine related data D3 are genuine. With the configuration, it is possible to confirm whether or not data decryption has been made correctly. Even when data decryption succeeds albeit a false encryption key is used for the data decryption, it is possible to prevent that whether or not data are genuine is erroneously determined based on the data decrypted with the false encryption key.

The marine propulsion device <NUM> further includes the propeller <NUM>, the crankshaft <NUM>, and the crank angle sensor <NUM> (exemplary rotation speed sensor). The crankshaft <NUM> is rotated by the engine <NUM> and transmits the driving force of the engine <NUM> to the propeller <NUM>. The ECU <NUM> determines whether or not the propeller <NUM> has been contacted by an object based on the detection signal transmitted thereto from the crank angle sensor <NUM>. The engine related data D3 include information related to contact of an object against the propeller <NUM>. Thus, the ECU <NUM> encrypts the information that the propeller <NUM> has been contacted by an object and transmits the encrypted information to the cloud server <NUM>; then, the cloud server <NUM> determines whether or not the engine related data D3 are genuine based on the engine operating time D2. Because of this, it is possible to prevent a type of falsification of deleting a record that the propeller <NUM> has been contacted by an object.

The marine propulsion device <NUM> further includes the propeller <NUM>, the crankshaft <NUM>, the crank angle sensor <NUM> (exemplary rotation speed sensor), and the intake pressure sensor <NUM>. The crankshaft <NUM> is rotated by the engine <NUM> and transmits the driving force of the engine <NUM> to the propeller <NUM>. The ECU <NUM> determines whether or not the propeller <NUM> has been contacted by an object based on the detection signals transmitted thereto from the intake pressure sensor <NUM> and the crank angle sensor <NUM>. The engine related data D3 include information related to contact of an object against the propeller <NUM>. Thus, the ECU <NUM> encrypts the information that the propeller <NUM> has been contacted by an object and transmits the encrypted information to the cloud server <NUM>; then, the cloud server <NUM> determines whether or not the engine related data D3 are genuine based on the engine operating time D2. Because of this, it is possible to prevent the type of falsification of deleting a record that the propeller <NUM> has been contacted by an object.

The marine propulsion device <NUM> further includes the propeller <NUM>, the crankshaft <NUM>, the crank angle sensor <NUM>, and the cam angle sensor <NUM> (exemplary reverse rotation detector). The crankshaft <NUM> is rotated by the engine <NUM> and transmits the driving force of the engine <NUM> to the propeller <NUM>. The crank angle sensor <NUM> and the cam angle sensor <NUM> detect information related to reverse rotation of the crankshaft <NUM>. The ECU <NUM> determines whether or not the crankshaft <NUM> has been reversely rotated based on the information detected by the crank angle sensor <NUM> and the cam angle sensor <NUM>. The engine related data D3 include information related to reverse rotation of the crankshaft <NUM>. Thus, the ECU <NUM> encrypts the information that the crankshaft <NUM> has been reversely rotated and transmits the encrypted information to the cloud server <NUM>; then, the cloud server <NUM> determines whether or not the engine related data D3 are genuine based on the engine operating time D2. Because of this, it is possible to prevent a type of falsification of deleting a record that the crankshaft <NUM> has been reversely rotated.

The DCM <NUM> includes the GPS module <NUM> (exemplary position detector) for detecting the position of the watercraft <NUM>. The DCM <NUM> transmits the positional information (exemplary detected positional data) detected by the GPS module <NUM> to the cloud server <NUM>. The cloud server <NUM> determines that a misconduct has been done when movement of the watercraft <NUM> has been detected based on the GPS module <NUM>, while the serial number D1, the encrypted engine operating time D2, and the encrypted engine related data D3 have not been received by the cloud server <NUM>. The misconduct can be exemplified by, for instance, cutting/disconnecting of a wiring for connection between the DCM <NUM> and the ECU <NUM>. The reason for providing this example is that, when cutting/disconnecting of the wiring between the DCM <NUM> and ECU <NUM> is done, the positional information D4 detected by the DCM <NUM> becomes the only data to be transmitted to the cloud server <NUM>.

In the preferred embodiment described above, whether or not the crankshaft <NUM> has been reversely rotated is configured to be determined by the ECU <NUM>; however, this may not be necessarily determined by the ECU <NUM> and may be determined by the cloud server <NUM>. In this case, the ECU <NUM> encrypts the detection signals transmitted thereto from the crank angle sensor <NUM> and the cam angle sensor <NUM>. The encrypted detection signals are included in the encrypted engine related data D3. The DCM <NUM> transmits the serial number D1, the encrypted engine operating time D2, and the encrypted engine related data D3 to the cloud server <NUM>. The cloud server <NUM> determines whether or not the crankshaft <NUM> has been reversely rotated based on the decrypted detection signals of the crank angle sensor <NUM> and the cam angle sensor <NUM>.

In the preferred embodiment described above, whether or not the propeller <NUM> has been contacted by an object is configured to be determined by the ECU <NUM>; however, this may not be necessarily detected by the ECU <NUM> and may be determined by the cloud server <NUM>. In this case, the ECU <NUM> encrypts the detection signals of the crank angle sensor <NUM> and the intake pressure sensor <NUM>. The encrypted detection signals are included in the encrypted engine related data D3. The DCM <NUM> transmits the serial number D1, the encrypted engine operating time D2, and the encrypted engine related data D3 to the cloud server <NUM>. The cloud server <NUM> determines whether or not the propeller <NUM> has been contacted by an object based on the decrypted detection signals of the crank angle sensor <NUM> and the intake pressure sensor <NUM>.

In the preferred embodiment described above, the DCM <NUM> is provided with the GPS module <NUM> but may not be provided with the GPS module <NUM>. In this case, the DCM <NUM> transmits the engine serial number D1, the encrypted engine operating time D2, and the encrypted engine related data D3 to the cloud server <NUM>.

In the preferred embodiment described above, the ECU <NUM> is configured to obtain the flow rate of fuel by cumulating the amount of fuel injected by the fuel injection device <NUM>. However, the flow rate of fuel may not be necessarily obtained as described above. For example, a fuel flow rate sensor may be provided as a discrete component; then, the flow rate of fuel may be obtained by obtaining a detection signal outputted from the fuel flow rate sensor.

In the preferred embodiment described above, the marine propulsion device information transmitting and receiving system <NUM> includes the cloud server <NUM>; however, the marine propulsion device information transmitting and receiving system <NUM> may not necessarily include the cloud server <NUM> but may include a physical server.

According to the present invention, it is possible to provide a marine propulsion device information transmitting and receiving system and a marine propulsion device information transmitting and receiving method, whereby data related to an engine of a watercraft can be inhibited from being falsified.

Claim 1:
A marine propulsion device information transmitting and receiving system (<NUM>) comprising:
a server (<NUM>); and
a watercraft (<NUM>) including a marine propulsion device (<NUM>) and a communication device configured to perform communication with the server (<NUM>), wherein
the marine propulsion device (<NUM>) includes an engine (<NUM>) and a controller (<NUM>), the controller (<NUM>) being connected to the communication device,
the controller (<NUM>) is configured to encrypt data (D3) related to the engine (<NUM>) with an encryption key associated with information (D1) unique to the engine (<NUM>),
the communication device is configured to transmit the encrypted data (D3) related to the engine (<NUM>) to the server (<NUM>), and
the server (<NUM>) is configured to receive the information (D1) unique to the engine (<NUM>), and the encrypted data (D3) related to the engine (<NUM>), the server (<NUM>) being configured to decrypt the encrypted data (D3) related to the engine (<NUM>) with the encryption key associated with information (D1) unique to the engine (<NUM>), characterized in that
the controller (<NUM>) is configured to control the engine (<NUM>) and configured to encrypt an operating time (D2) of the engine (<NUM>) with the encryption key associated with information (D1) unique to the engine (<NUM>),
the communication device is configured to transmit the information (D1) unique to the engine (<NUM>) and the encrypted operating time (D2) of the engine (<NUM>) to the server (<NUM>), and
the server (<NUM>) is configured to receive the encrypted operating time (D2) of the engine (<NUM>), and being configured to decrypt the encrypted operating time (D2) of the engine (<NUM>) an encryption key that is associated with the information (D1) unique to the engine (<NUM>), the server (<NUM>) is configured to decrypt the encrypted data (D3) related to the engine (<NUM>) with the encryption key associated with the information (D1) unique to the engine (<NUM>), and
the server (<NUM>) being configured to determine whether or not the decrypted data (D3) related to the engine (<NUM>) are genuine based on the decrypted operating time (D2) of the engine (<NUM>).