JP7626322B2 - Combustion pressure data transmission device, ship-to-shore communication system equipped with the same, and combustion pressure data transmission method - Google Patents

Description

The present invention relates to a combustion pressure data transmission device installed on a ship, a ship-to-shore communication system equipped with the same, and a combustion pressure data transmission method.

It is known to acquire combustion pressure data of an internal combustion engine, such as an engine, in order to diagnose the condition of the internal combustion engine or detect signs of deterioration, etc., based on the combustion conditions of the internal combustion engine. In addition, the acquired combustion pressure data is also transmitted to a management device installed in a location separate from the facility or mobile object equipped with the internal combustion engine, and the data is analyzed in the management device.

If this technology is applied to an internal combustion engine installed on a ship, the combustion pressure data acquired on board the ship will be transmitted to a management device on land. For land-based facilities or mobile bodies, data can be transmitted cheaply and quickly by communication via the Internet from multiple access points, not only via wired communication but also wireless communication.

On the other hand, since ships travel on ocean routes far from access points installed on land, it is necessary to use satellite communications to transmit data from the ship to a management device on land (see, for example, Patent Document 1 below). When using satellite communications to transmit data, communication fees are higher than communications via the Internet on land, and it is not practical to constantly transmit combustion pressure data that changes from moment to moment.

When extracting and transmitting specific data to reduce communication volume, setting an arbitrary time for extracting the data may affect the analysis of the data in the management device, which may result in a failure to perform the analysis correctly. In addition, the following Patent Document 2 discloses a method for reducing communication volume by comparing the data transmitted last time with the data to be transmitted this time, and transmitting only the data that differs from the previous time.

However, if this method is applied to combustion pressure waveform data, which is prone to fluctuations due to disturbances, there is a risk that the amount of communication will not be reduced because there will be almost no data that has the same value as the previous time due to fluctuations in the value (combustion pressure) on the same horizontal axis (for example, the crank angle of an internal combustion engine).

JP 2014-75654 A Japanese Unexamined Patent Publication No. 62-39941

The present invention has been made in consideration of the above, and aims to provide a combustion pressure data transmission device, a ship-to-shore communication system including the same, and a combustion pressure data transmission method that can reduce the amount of data transmitted from the ship to shore via satellite communication while providing data content that enables a management device on land to properly monitor the status of an internal combustion engine installed on a ship.

A combustion pressure data transmitting device according to one embodiment of the present invention is a combustion pressure data transmitting device installed on a ship to transmit combustion pressure data of an internal combustion engine installed on the ship using a ship-to-shore communication system that transmits data from the ship to a management device on land via satellite communication, and is equipped with a condition determination unit that acquires predetermined condition data related to the internal combustion engine and different from the combustion pressure data and determines whether the condition data satisfies a predetermined condition, a combustion pressure data extraction unit that extracts combustion pressure data of the internal combustion engine for at least a portion of an extraction period during which the condition is satisfied, and a signal generation unit that generates a data transmission signal for transmitting the extracted combustion pressure data to the management device.

According to the above configuration, when predetermined condition data related to the internal combustion engine and different from the combustion pressure data satisfies a predetermined condition, the combustion pressure data of the internal combustion engine during at least a part of the extraction period during which the condition is satisfied is extracted. Therefore, the combustion pressure data when the internal combustion engine is in a predetermined state is transmitted. This makes it possible to transmit combustion pressure data that matches the conditions to be analyzed by the management device. As a result, it is possible to reduce the amount of data transmitted from the ship to the land via satellite communication while ensuring that the data content enables the land-based management device to appropriately monitor the state of the internal combustion engine installed on the ship.

The condition determination unit may determine whether the period during which the condition data is in a predetermined state continues for a predetermined reference period or longer, and determine that the condition is satisfied if the period during which the predetermined state continues for a predetermined reference period or longer, and the combustion pressure data extraction unit may acquire the combustion pressure data during the extraction period at each predetermined data acquisition interval, and extract at least a portion of the combustion pressure data acquired during the period during which the condition is satisfied as combustion pressure data to be transmitted to the management device .

According to the above configuration, the combustion pressure data of the internal combustion engine is extracted when the period during which the internal combustion engine is in a predetermined state continues for a predetermined reference period or longer. Therefore, it is possible to transmit the combustion pressure data when the internal combustion engine is stable in that state. This makes it possible to extract more appropriate combustion pressure data that matches the conditions to be analyzed by the management device.

The extraction period may be the period between when the crank angle of the internal combustion engine reaches a predetermined start angle and when the crank angle of the internal combustion engine reaches a predetermined end angle. This allows combustion pressure data to be transmitted in a specific state of the internal combustion engine (scavenging, compression, combustion, exhaust, etc.).

The condition determination unit may determine that the condition is satisfied when a state in which a variance, a standard deviation, or a coefficient of variation of the condition data acquired during a period determined by the data acquisition interval of the combustion pressure data is within a predetermined threshold range continues for the reference period. By performing a condition determination based on the variance, the standard deviation, or the coefficient of variation of the condition data during a period determined by the data acquisition period of the combustion pressure data , it is possible to transmit combustion pressure data related to the state of the internal combustion engine to be analyzed by the management device while allowing a certain degree of disturbance.

The condition data may be data that changes depending on changes in the load on the internal combustion engine. This makes it possible to transmit combustion pressure data when the internal combustion engine is in a specified load condition.

The condition data may include at least one of engine load data, engine speed data, fuel injection amount data, engine load command value data, engine speed command value data, fuel injection amount command value data, and turbocharger speed data.

The combustion pressure data extraction unit may have a data interpolation unit that determines whether or not there is a gap in the extracted combustion pressure data, and if there is a gap, interpolates the data of the missing portion from the data before and after the missing portion. Even if there is a gap in the extracted combustion pressure data, by performing data interpolation in advance at the sender of the combustion pressure data (the ship side), it becomes unnecessary to separately send information (data) indicating the existence of missing data to the management device. In addition, it is possible to eliminate the rejection of data due to missing data in the management device, and to efficiently transmit valid combustion pressure data.

The condition determination unit may have a condition setting unit that can change the conditions. By allowing various conditions to be set, combustion pressure data in multiple states of the internal combustion engine can be easily extracted and transmitted.

The internal combustion engine may have a plurality of cylinders, and the combustion pressure data extraction unit may extract the combustion pressure data for at least one cylinder that is designated in advance among the plurality of cylinders.

A ship-to-shore communication system according to another aspect of the present invention includes the above-described combustion pressure data transmitting device,
and a management device that is provided on land and transmits and receives data to and from the combustion pressure data transmitting device via satellite communication.

A combustion pressure data transmission method according to another aspect of the present invention is a combustion pressure data transmission method for transmitting combustion pressure data of an internal combustion engine installed on a ship using a ship-to-shore communication system that transmits data from the ship to a management device on land via satellite communication, the method obtaining specified condition data related to the internal combustion engine and different from the combustion pressure data , determining whether the condition data satisfies a predetermined condition, extracting combustion pressure data of the internal combustion engine for at least a portion of an extraction period during which the condition is satisfied, generating a data transmission signal for transmitting the extracted combustion pressure data to the management device, and transmitting the data transmission signal to the management device.

The present invention makes it possible to reduce the amount of data transmitted from the ship to the shore via satellite communication while providing data content that enables the onshore management device to properly monitor the status of the internal combustion engine installed on the ship.

FIG. 1 is a block diagram showing a schematic configuration of a ship-to-shore communication system to which a combustion pressure data transmitting device according to an embodiment of the present invention is applied. FIG. 2 is a diagram showing functional blocks in the data transmission device shown in FIG. FIG. 3 is an image diagram illustrating a combustion data extraction mode in this embodiment.

Below, the embodiment of the present invention will be described in detail with reference to the drawings. Note that, in the following, the same or corresponding elements are given the same reference numerals throughout the drawings, and duplicated explanations will be omitted.

Figure 1 is a block diagram showing the schematic configuration of a ship-to-shore communication system to which a combustion pressure data transmission device according to one embodiment of the present invention is applied. In this embodiment, the ship-to-shore communication system 1 includes an on-board system 2 provided on a ship 4 and a management device 3 provided on land.

The vessel 4 is equipped with an internal combustion engine 5, an engine control device 6a that controls the internal combustion engine 5, and an engine measurement device 6b that measures the state of the internal combustion engine 5. The engine control device 6a acquires data related to the internal combustion engine 5 and controls the internal combustion engine 5 based on the data. The engine measurement device 6b also measures the combustion pressure data (combustion waveform data) of the internal combustion engine 5. The internal combustion engine 5 is equipped with, for example, a large two-cycle (two-stroke) engine 10 (hereinafter simply referred to as the engine) that is the main engine for propulsion of the vessel 4, and a supercharger 20 that compresses air to supply scavenging air to the engine 10. The engine 10 may be an engine for generating electricity for the vessel 4. Also, instead of the two-cycle engine 10, a four-cycle (four-stroke) engine may be provided. In this case, "scavenging air" in the following description is replaced with "air supply".

The engine 10 has multiple cylinders 11 (only one is shown in FIG. 1). In particular, in a uniflow two-stroke engine, each cylinder 11 has a scavenging port 12 formed in the lower part and an exhaust port 13 formed in the upper part. Each cylinder 11 is provided with a piston 14, a fuel injection valve 15, and an exhaust valve 16. The piston 14 slides inside the cylinder 11 across the scavenging port 12, and its lower end is connected to a crankshaft 18 via a connecting rod 17.

The fuel injection valve 15 is located in the upper part of the cylinder 11, and fuel is supplied from a fuel supply device 31. The fuel supply device 31 can change the fuel injection pattern and fuel injection timing of the fuel injection valve 15. The exhaust valve 16 is a valve that opens and closes the exhaust port 13, and is driven by an exhaust valve drive device 32. The exhaust valve drive device 32 can change the opening and closing pattern and opening and closing timing of the exhaust valve 16.

The turbocharger 20 is configured to adiabatically compress the air supplied to the engine 10. The turbocharger 20 includes a compressor 22 having a plurality of compressor blades that rotates around a rotating shaft 23 to compress air introduced from the outside, and a turbine 21 that is connected to the rotating shaft 23 of the compressor 22 and generates the rotational power of the compressor 22.

The air compressed by the compressor 22 is supplied to the engine 10 as scavenging air via the scavenging pipe 24 and scavenging chamber 25. Exhaust gas discharged from combustion in the engine 10 flows into the turbine 21 of the turbocharger 20. The turbine 21 has multiple turbine blades, and the exhaust gas rotates the turbine 21 around the rotating shaft 23, causing the compressor 22 to rotate.

The onboard system 2 is equipped with a data transmission device 7 for transmitting data acquired by the engine control device 6a and the engine measurement device 6b to the management device 3. The data transmission device 7 acquires specific data from the engine control device 6a and the engine measurement device 6b, and generates a data transmission signal for transmission to the management device 3. The data transmission device 7 includes a known computer device.

The onboard system 2 further includes an extraboard communication unit 8 that transmits the data transmission signal generated by the data transmission device 7 to the management device 3 via satellite communication. The data transmission device 7 and the extraboard communication unit 8 are connected to the onboard LAN 9 so that signals can be exchanged. The extraboard communication unit 8 includes a mail server capable of transmitting, for example, e-mail. Various data servers, computing devices, input devices, display devices, etc. can be connected to the onboard LAN 9.

The data transmission signal sent from the extravehicular communication unit 8 is transmitted by satellite communication via a communication satellite 40. The management device 3 may be provided with a satellite antenna 41 capable of receiving the data transmission signal by satellite communication. In addition to this, or instead of this, the data transmission signal may be received once by another satellite antenna 42 provided on land, and the data transmission signal may be transmitted from the satellite antenna 42 to the management device 3 via a communication network 43 such as the Internet.

The following describes how the data transmission device 7 transmits the combustion pressure data of the internal combustion engine 5 in this embodiment. That is, the data transmission device 7 in this embodiment functions as a combustion pressure data transmission device.

Figure 2 is a diagram showing the functional blocks of the data transmission device shown in Figure 1. As shown in Figure 2, the data transmission device 7 in this embodiment includes a condition determination unit 71, a combustion pressure data extraction unit 72, and a signal generation unit 73.

The condition determination unit 71 acquires predetermined condition data related to the internal combustion engine 5 and determines whether the condition data satisfies a predetermined condition. In this embodiment, the condition data is data that changes depending on changes in the load on the internal combustion engine 5.

The data that changes due to the load change of the internal combustion engine 5 may include engine load data obtained by directly or indirectly detecting the load on the moving parts of the internal combustion engine 5, fuel injection amount data obtained by detecting the amount of fuel injected from the fuel injection valve 15, engine speed command value data indicating the engine speed command value output from the engine control device 6a, fuel injection amount command value data indicating the fuel injection amount command value output from the engine control device 6a, and supercharger speed data obtained by detecting the speed of the supercharger 20. In addition, if the internal combustion engine 5 is an internal combustion engine for power generation, the engine load command value data may be used as the condition data in that case, since load control may be performed with the speed of the internal combustion engine 5 constant. The condition determination unit 71 may make a determination using any one of these data. Alternatively, the condition determination unit 1 may make a determination using multiple types of data among these data. In other words, the determination condition described later may be an AND condition or an OR condition for determining each of the multiple types of data.

The engine load data may be data detected by the load detector 51. For example, the load detector 51 may detect a displacement in the internal combustion engine 5 or an output shaft connected thereto. The engine measurement device 6b or the condition determination unit 71 may calculate the load from the detected displacement. The fuel injection amount and the engine speed may be obtained from the engine control device 6a, and the virtual load may be calculated from them. The fuel injection amount is detected by the fuel injection amount detector 61 provided in the fuel supply device 31 and sent to the engine control device 6a. The engine speed is detected by the engine speed detector 62 provided in the internal combustion engine 5 and sent to the engine control device 6a. Note that FIG. 2 illustrates both a mode in which the engine load data is obtained from the load detector 51 via the engine measurement device 6b and a mode in which the engine load data is obtained from the fuel injection amount detector 61 and the engine speed detector 62 via the engine control device 6a, but when the condition determination unit 71 obtains the engine load data, it is sufficient if it can obtain the engine load data in either one of these modes.

As described above, data (condition data) that changes due to changes in the load on the internal combustion engine 5 is input to the data transmission device 7 via the engine control device 6a and/or the engine measurement device 6b. Alternatively, the data transmission device 7 may acquire the condition data directly from the corresponding detectors 51, 61, 62, etc. Information on the judgment conditions is stored in a memory unit (not shown) of the data transmission device 7. The condition judgment unit 71 reads out the judgment conditions and judges whether the acquired condition data (engine load data) satisfies the judgment conditions.

In this embodiment, the condition determination unit 71 determines whether the period during which the variance of the condition data acquired for a predetermined period is within a predetermined threshold range continues for a predetermined reference period T _r (e.g., 30 minutes) or more, and determines that the condition is satisfied when the period in the predetermined state continues for the reference period T _r or more. The combustion pressure data extraction unit 72 extracts the combustion pressure data of the internal combustion engine 5 for at least a part of the period during which the condition is satisfied.

3 is an image diagram illustrating a combustion data extraction mode in this embodiment. The top graph is a graph showing a change in load over time. The engine measurement device 6b measures the combustion pressure from the combustion pressure detector 52 at a predetermined sampling period and generates combustion pressure data. The combustion pressure data extraction unit 72 periodically acquires the combustion pressure data from the engine measurement device 6b at a predetermined time interval (hereinafter referred to as a data acquisition interval _Td , for example, every 10 minutes). The combustion pressure data extraction unit 72 extracts the combustion pressure data of the internal combustion engine 5 during a predetermined extraction period from the acquisition timing.

The condition determination unit 71 calculates the variance V of the condition data in the data acquisition interval _Td for each combustion pressure data acquisition timing. The second graph from the top in FIG. 3 is a graph showing the time change of the variance of the load in a predetermined time interval _Td . The variance V is calculated by squaring the difference between the average value of each of the values of a plurality of data elements, adding them up, and dividing by the number of data elements. The condition determination unit 71 determines whether or not this variance V satisfies the condition (whether or not it is within the threshold range: 0≦V≦ _Vmax ). Furthermore, the condition determination unit 71 determines whether or not the state in which the variance V satisfies the condition has continued a predetermined number of times (for example, four times). For example, if the state in which the variance V satisfies the condition has continued four times in a row (if the condition is satisfied at any of the times _t1 to _t4 in FIG. 3), it is determined that the state in which the condition is satisfied has continued for a period of more than the reference period T _r (30 minutes).

At this time, the condition determination unit 71 determines that the period during which the condition data is in the predetermined state continues for a predetermined reference period T _r or more. The combustion pressure data extraction unit 72 extracts the third combustion pressure data (combustion pressure data acquired at time t ₃ ) from the combustion pressure data (four pieces of data) acquired during the period during which the condition is satisfied, as the combustion pressure data to be transmitted to the management device 3. That is, the combustion pressure data 20 minutes after the first acquisition timing at which the variance V satisfied the condition is extracted. In this way, the combustion pressure data extraction unit 72 extracts the combustion pressure data of the internal combustion engine ₅ during the predetermined extraction period T _e from the extraction start time (time t ₃ 20 minutes after the first acquisition timing at which the condition is satisfied) that is predetermined based on the start time (time t 1 ) of the reference period T _r .

The timing for extracting the combustion pressure data is not limited to the above as long as it is within the reference period _Td . For example, the extraction timing may be determined according to the characteristics of the internal combustion engine 5 of the ship 4 (e.g., the period from when the load changes until the load stabilizes, etc.). Furthermore, the combustion data may be extracted at multiple times within the reference period _Td .

The extraction period T _e is the period during which the crank angle of the internal combustion engine 5 changes from a predetermined start angle to a predetermined end angle. In this embodiment, the angle range from the start angle to the end angle is, for example, 360° (one cycle in a two-stroke engine), as shown in the bottom graph of Fig. 3. Note that in the graph of Fig. 3, 0° is set when the piston 14 is at the top dead center, and the angle range is from -180° to 180° based on this.

The extracted combustion pressure data is a collection of combustion pressure values for each specified angle unit. For example, if the extraction period is 360° and the angle unit is 0.5°, 720 data elements are extracted.

The combustion pressure data extraction unit 72 extracts combustion pressure data for at least one pre-specified cylinder 11 among the multiple cylinders 11 of the engine 10.

The signal generating unit 73 generates a data transmission signal for transmitting the extracted combustion pressure data to the management device 3. The data transmission signal may include the extracted combustion pressure data and associated data. The associated data may include, for example, the identification number of the internal combustion engine 5, data on the date and time when the combustion pressure data to be transmitted was extracted, information on the load at the time of extraction (actual value, average value, variance value, etc.). The associated data may also include information on the cylinder 11 from which the combustion pressure data was extracted (such as the identification number of the specified cylinder 11). Alternatively, the extracted cylinder 11 may not be distinguished, and the data may be regarded as the combustion pressure data of the engine 10.

In addition, the combustion pressure data extraction unit 72 may extract combustion pressure data for two or more of the multiple cylinders 11, and the signal generation unit 73 may average them to generate a single combustion pressure data.

According to the above configuration, when the specified condition data related to the internal combustion engine 5 satisfies a predetermined condition, the combustion pressure data of the internal combustion engine 5 during at least a part of the period during which the condition is satisfied is extracted. Therefore, the combustion pressure data when the internal combustion engine 5 is in a specified state is transmitted. This makes it possible to transmit combustion pressure data that matches the conditions to be analyzed by the management device 3. As a result, it is possible to reduce the amount of data transmitted from the ship 4 to the land via satellite communication while providing data content that allows the land-based management device 3 to appropriately monitor the state of the internal combustion engine 5 installed on the ship 4.

Furthermore, according to the above configuration, when the period during which the internal combustion engine 5 is in a predetermined state continues for a predetermined reference period T _r or more, the combustion pressure data of the internal combustion engine 5 is extracted. Therefore, it is possible to transmit the combustion pressure data when the internal combustion engine 5 is stable in that state. This makes it possible to extract more appropriate combustion pressure data as the combustion pressure data that matches the condition to be analyzed by the management device 3. In addition, by performing the condition determination based on the variance of the condition data, it is possible to transmit the combustion pressure data related to the state of the internal combustion engine 5 to be analyzed by the management device 3 while allowing a certain degree of disturbance.

Moreover, by determining the condition using data that changes depending on the load of the internal combustion engine 5 as the condition data, it is possible to transmit the combustion pressure data when the internal combustion engine 5 is in a predetermined load state. Also, by extracting the combustion pressure data for the period _Te from the crank angle of the internal combustion engine to a predetermined end angle, it is possible to transmit the combustion pressure data in a specific state (scavenging, compression, combustion, exhaust, etc.) of the internal combustion engine 5.

In this embodiment, the combustion pressure data extraction unit 72 includes a data interpolation unit 75. The data interpolation unit 75 determines whether or not there is a missing portion in the extracted combustion pressure data, and if there is a missing portion, it interpolates the data of the missing portion from the data before and after the missing portion. As described above, the combustion pressure data extracted in this embodiment is configured as a set of combustion pressure values for each predetermined angle unit. If the combustion pressure value at a certain crank angle in a portion of the combustion pressure data cannot be obtained for some reason, the data interpolation unit 75 interpolates from the combustion pressure values at crank angles before and after the crank angle in the missing data element. An appropriate data interpolation method is adopted from among known interpolation methods, such as linear interpolation.

In this way, even if some of the extracted combustion pressure data is missing, the source of the combustion pressure data (ship 4) can perform data interpolation in advance, eliminating the need to send information (data) indicating that there is missing data to the management device 3. This also eliminates the rejection of data due to some data being missing in the management device 3, making it possible to efficiently transmit valid combustion pressure data.

In addition, in this embodiment, the condition determination unit 71 has a condition setting unit 74 that can change the settings of the conditions. For example, the condition can be set and input in an input device (not shown) to the data transmission device 7. The condition setting unit 74 sets the conditions based on the contents of the input from the input device.

In addition to this, or instead of this, the condition setting unit 74 may automatically select and set one condition from multiple conditions previously stored in a storage unit or the like. For example, loads of 70%, 50%, and 30% may be set as multiple conditions, and after a first condition (e.g., load 70%) is satisfied and the combustion pressure data extraction unit 72 extracts the combustion pressure data at that time, the condition setting unit 74 may change the condition to a second condition (e.g., load 50%). In this way, the conditions may be configured to be switched in order as soon as the combustion pressure data under the currently set condition is extracted.

The condition setting unit 74 may also make judgments in parallel for multiple conditions. In this case, the condition judgment unit 71 judges that the condition is satisfied when the load is, for example, 70%, 50%, or 30%. The signal generation unit 73 generates a data transmission signal that includes the extracted combustion pressure data and the condition content at that time (information on which of the multiple conditions is satisfied).

Of course, the condition setting unit 74 may maintain the previous conditions in order to extract combustion pressure data multiple times under the same conditions.

In this way, by allowing various conditions to be set, combustion pressure data for multiple states of the internal combustion engine 5 can be easily extracted and transmitted.

The above describes an embodiment of the present invention, but the present invention is not limited to the above embodiment, and various improvements, changes, and modifications are possible without departing from the spirit of the invention.

For example, in the above embodiment, the condition for judgment in the condition judgment unit 71 is set to a period during which the condition data (variance) falls within a predetermined threshold range for a predetermined reference period T _r or more, but this is not limited to the above. For example, the condition for judgment may include at least one of the following: the value of the condition data in the reference period is within a predetermined threshold range; the average value, variance, standard deviation, or coefficient of variation of the condition data in the reference period is within a predetermined threshold range; and the number of times the condition data falls outside the predetermined threshold range in the reference period is within a predetermined number of times. Note that the standard deviation is given by the square root of the variance, and the coefficient of variation is given by dividing the standard deviation by the average value.

In addition, in the above embodiment, the angle range of the crank angle in the extracted combustion pressure data is 360°, but this is not limited to this. For example, the angle range may be less than 360°, 360° (one cycle), or greater than 360°. If the angle range is greater than 360°, X (X≧2) cycles of combustion pressure data may be extracted as is, or X cycles may be extracted and the combustion pressure data for one cycle averaged for each angle may be transmitted as the combustion pressure data. In this way, by averaging X cycles of combustion pressure data, the amount of transmission can be reduced.

In the above embodiment, the data transmission signal generated by the signal generation unit 73 of the data transmission device 7 is transmitted to the extraboard communication unit 8, and the extraboard communication unit 8 transmits data to the management device 3 on land via satellite communication. However, the data transmission device 7 may transmit data directly to the management device 3 on land via satellite communication. In other words, the data transmission device 7 may be equipped with an extraboard communication unit that performs satellite communication.

The internal combustion engine 5 from which the combustion pressure data can be extracted is not particularly limited as long as it is a combustion engine installed in the ship 4. For example, the internal combustion engine 5 may include internal combustion engines for various purposes, such as a main propulsion engine, various auxiliary engines, and an internal combustion engine for onboard power generation.

The present invention is useful for providing a combustion pressure data transmission device, a ship-to-shore communication system including the same, and a combustion pressure data transmission method that can reduce the amount of data transmitted from the ship to shore via satellite communication while providing data content that enables a management device on land to properly monitor the status of an internal combustion engine installed on a ship.

1 Ship-to-shore communication system 3 Management device 4 Ship 5 Internal combustion engine 7 Data transmission device (combustion pressure data transmission device)
71 Condition determination unit 72 Combustion pressure data extraction unit 73 Signal generation unit 74 Condition setting unit 75 Data interpolation unit

Claims (8)

A combustion pressure data transmitting device provided on a ship for transmitting combustion pressure data of an internal combustion engine provided on the ship using a ship-to-shore communication system that transmits data from the ship to a management device on land via satellite communication, comprising:
a condition determination unit that obtains predetermined condition data related to the internal combustion engine and different from the combustion pressure data, and determines whether the condition data satisfies a predetermined condition;
a combustion pressure data extraction unit that extracts combustion pressure data of the internal combustion engine during at least a part of an extraction period during which the condition is satisfied;
a signal generating unit that generates a data transmission signal for transmitting the extracted combustion pressure data to the management device ;
the condition data is data that changes due to a change in load on the internal combustion engine,
The combustion pressure data extraction unit periodically acquires the combustion pressure data at a predetermined data acquisition interval,
the condition determination unit determines that the condition is satisfied when a state in which a variance, a standard deviation, or a coefficient of variation of the condition data acquired during a period determined by the data acquisition interval of the combustion pressure data is within a predetermined threshold range continues for the reference period or longer,
The combustion pressure data extraction unit extracts combustion pressure data for at least a portion of the combustion pressure data acquired during a period in which the condition is satisfied, the combustion pressure data for the extraction period being shorter than the data acquisition interval, for transmission to the management device . 2. The combustion pressure data transmitting device according to claim 1 , wherein the extraction period is a period from a predetermined start angle to a predetermined end angle of the crank angle of the internal combustion engine. 3. The combustion pressure data transmitting device according to claim 1, wherein the condition data includes at least one of engine load data, engine speed data, fuel injection amount data, engine load command value data, engine speed command value data, fuel injection amount command value data , and turbocharger speed data. 4. The combustion pressure data transmitting device according to claim 1, wherein the combustion pressure data extracting unit determines whether or not the extracted combustion pressure data is missing, and if there is a missing portion, has a data interpolating unit that interpolates data of the missing portion from data before and after the missing portion. 5. The combustion pressure data transmitting device according to claim 1, wherein the condition determining section has a condition setting section that is capable of changing the setting of the condition. The internal combustion engine includes a plurality of cylinders.
6. The combustion pressure data transmitting device according to claim 1, wherein the combustion pressure data extracting unit extracts the combustion pressure data for at least one cylinder designated in advance among the plurality of cylinders. A combustion pressure data transmitting device according to any one of claims 1 to 6 ,
a management device that is provided on land and transmits and receives data to and from the combustion pressure data transmitting device via satellite communication. A combustion pressure data transmission method for transmitting combustion pressure data of an internal combustion engine provided on a ship using a ship-to-shore communication system for transmitting data from a ship to a management device on land via satellite communication, comprising the steps of:
The combustion pressure data is periodically acquired at a predetermined data acquisition interval.
acquiring data relating to the internal combustion engine , the data being changed due to a load change of the internal combustion engine as predetermined condition data different from the combustion pressure data, and determining whether or not the condition data satisfies a predetermined condition;
determining that the condition is satisfied when a state in which a variance, a standard deviation, or a coefficient of variation of the condition data acquired during a period determined by the data acquisition interval of the combustion pressure data is within a predetermined threshold range continues for more than the reference period;
extracting combustion pressure data of the internal combustion engine during an extraction period that is shorter than the data acquisition interval from the combustion pressure data acquired during a period in which the condition is satisfied;
generating a data transmission signal for transmitting the extracted combustion pressure data to the management device;
A combustion pressure data transmission method, comprising: transmitting the data transmission signal to the management device.

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