AIS-based port cargo ship and port ship operation carbon emission estimation method and system

Abstract

The invention relates to the field of carbon emission, in particular to an AIS-based port cargo ship and port ship operation carbon emission estimation method and system. The method comprises the following steps: acquiring AIS data, VTS range data and berth range data of port cargo ships and port ships; according to the AIS data of the port cargo ship and the port ship, track point cleaning is carried out, and a cleaned track point set is obtained; according to the cleaned track point set and the VTS range data, obtaining an accumulated voyage in each VTS range; according to the cleaned track point set and the berth range data, port ship operation track points are obtained; the total carbon emission amount of the port cargo ship is calculated according to the accumulated voyage in each VTS range; and calculating the total carbon emission of the port ship according to the port ship operation track point. According to the method, high-cost real-time direct measurement and calculation of the carbon emission are avoided, the total carbon emission amount of the port cargo ship and the total carbon emission amount of the port ship are calculated respectively, and the carbon emission of the port is estimated more comprehensively.

Description

Technical Field

[0001] The present invention relates to the field of carbon emission, and more specifically, to a method and system for estimating carbon emission of port cargo ships and port-operating ships based on AIS. Background Art

[0002] CO2 emissions from the shipping industry account for about 3% of the world's total emissions. According to forecasts, if no measures are taken, greenhouse gas emissions from ships will increase by 150% to 250% by 2050 compared to 2012, and their share of global emissions will also increase significantly. As an important node for water and land transportation, ports are an important part of the transportation industry. In recent years, with the increasing requirements for green and low-carbon development, port companies have paid more and more attention to the accounting and reporting of carbon emissions. At present, the carbon emissions of port cargo ships are mostly calculated by direct measurement, but the cost of direct measurement of CO2 is relatively expensive, and it is difficult for port companies to obtain the carbon emissions of cargo ships that are not operated by themselves in the port area. In addition, most studies only focus on the carbon emissions of cargo ships in the port area, and the overall estimation of carbon emissions of port tugboats in the port area, the spatial pattern of carbon emissions, and near-real-time simulation research are ignored. Port tugboats bear the carbon emissions of the port area caused by the shutdown of cargo ship operators during the period of cargo ship docking and cargo ship departure with high-frequency traction work. Since the entire process of "entering the port-berthing-unberthing-leaving the port" of the port tugboat is closely related to the cargo ship, and there is a high degree of overlap in position, a comprehensive, efficient and low-cost calculation method and system can be provided in combination with the AIS trajectory of the ship in the port area.

[0003] The prior art discloses a device for monitoring carbon emissions of ships, which is used to monitor the carbon emissions of ships, including: a first receiving module receives AIS information sent by an AIS transmitter; a second receiving module receives shipboard remote terminal information sent by a shipboard remote terminal; a storage module stores a gaseous emission ratio coefficient model, ship archive information, ship fuel supply registration information, AIS information and shipboard remote terminal information; a calculation module calls the ship archive information and ship fuel supply information according to the ship identification number, and obtains the gaseous emission ratio coefficient of each type of engine in combination with the gaseous emission ratio coefficient model, and calculates the total carbon emissions of the ship according to the gaseous emission ratio coefficient, AIS information and shipboard remote terminal information. However, the above method does not comprehensively consider the total carbon emissions of port cargo ships and the total carbon emissions of port-operating ships, so it is not comprehensive enough. There is already guidance for port-operating tugboats and port-entering cargo ships to optimize the energy conservation and emission reduction of ship stop paths, but there is also a lack of specific guidance basis and data support. Summary of the invention

[0004] The purpose of the present invention is to break through the previous related methods that AIS is only used to estimate carbon emissions of cargo ships based on a set of cargo ship AIS trajectory data and port tugboat data, and expand the research object of carbon emissions of port area ships to two parts: the process of cargo ships entering and leaving the port and the process of port tugboat operations, that is, the entry and exit of ships is the first part of the carbon emission process, and the part where the tugboat operates on the stopped cargo ship and moves it to the berth is the second part of the carbon emission process. Based on AIS data, the present invention can achieve near real-time estimation of carbon emissions with a time resolution of 10 minutes, a spatial resolution of 1km*1km in the port area, and grams (g) as the finest weight unit. Compared with the carbon emission estimation of traditional port ships, the method and system for estimating carbon emissions from port cargo ships and port ship operations of the present invention have higher time and spatial resolution, lower estimation cost, and more comprehensive estimation results.

[0005] In order to achieve the above object, the present invention provides a method for estimating carbon emissions of port cargo ships and port-operating ships based on AIS, comprising:

[0006] S1: Obtain AIS data, VTS range data and berth range data of port cargo ships and port-operating ships;

[0007] S2: Clean the track points according to the AIS data of the port cargo ships and port ships to obtain a set of cleaned track points;

[0008] S3: Obtain the cumulative voyage within each VTS range according to the set of trajectory points after cleaning and the VTS range data; obtain the port ship operation trajectory points according to the set of trajectory points after cleaning and the berth range data;

[0009] S4: Calculate the total carbon emissions of port cargo ships based on the cumulative voyage within each VTS section; calculate the total carbon emissions of port ships based on the operation trajectory points of port ships.

[0010] Furthermore, in step S1, the AIS data of port cargo ships and port working vessels are text data stored based on the Maritime Mobile Service Identifier MMSI, including static data and dynamic data, wherein the static data includes the length and maximum tonnage of the cargo ship; and the dynamic data includes the position and speed of the cargo ship.

[0011] Furthermore, dynamic data can be expressed as L = {A i |i=1,…,m}, m represents the number of ships; read the trajectory data information of a ship within a certain time range, and construct a ship trajectory set A with MMSI as the unique identifier. i = {I i,j |j=1,2,…,n}, where n is the number of ship trajectory points, I i,j ={t i,j ,lon i,j ,lat i,j ,vi,j} is a four-tuple, I i,j Indicates that the ship is at t i,j The trajectory point information at the time, lon i,j t i,j The longitude of the vessel at the moment, lat i,j t i,j The dimension of the ship at the moment, v i,j t i,j The speed at which the ship is travelling at a given moment.

[0012] Furthermore, in step S2, it includes: using distance and speed thresholds to eliminate abnormal trajectory points, and compressing the trajectory points, specifically:

[0013] S2.1: Calculate the trajectory points I at adjacent moments i,j with I i,j+1 The distance between i,j ,I i,j+1 ], the compression distance threshold is δ d , if d[I i,j ,I u,j+1 ]>δ d , keep I i,j+1 Otherwise, delete I i,j+1 ; The removal distance threshold is ε d , if d[I i,j ,I i,j+1 ]<ε d , keep I i,j+1 Otherwise, delete I i,j+1 ; The calculation method is:

[0014] dlon=lon i,j -lon i,j+1 , dlat = lat i,j -lat i,j+1 ,

[0015] a=sin(dlat / 2)*2+cos(lat i,j )*cos(lat i,j+1 )*sin(dlon / 2)*2

[0016] c=2*atan2(sqrt(a),sqrt(1-a))

[0017] d[I i,j ,I i,j+1 ]=R*c (R represents the radius of the earth)

[0018] S2.2: Calculate the trajectory points I at adjacent moments i,j with I i,j+1 Sailing speed difference v[Iu,j ,I i,j+1 ], the speed threshold is δ v , if v[I i,j ,I i,j+1 ]<δ v , keep I i,j+1 Otherwise, delete I i,j+1 , the calculation formula is as follows:

[0019] v[I i,j ,I i,j+1 ]=abs(v i,j -v i,j+1 )

[0020] S2.3: Return to step S2.1 until all the track points of the ships are processed.

[0021] Further, in step S3, the cumulative voyage within each VTS range is obtained according to the cleaned track point set and the VTS range data, and the sjoin module of the Geopandas package is used in Python to perform spatial intersection judgment: a new field 1 is added as an attribute of the track point, and the intersection information is recorded in the AIS text data of field 1. The field 1 of the track point within the VTS range is marked as T, otherwise it is marked as F; in the AIS text data of the newly added field 1, the track points are sorted in time order, and the AIS track point is divided into multiple segments in turn according to whether the field 1 of the track point is marked as T or F. The time difference Δt between the two segments marked as T entering and exiting the VTS track is calculated. If it is less than the time threshold, the latter segment should be merged with the former segment to form a complete segment, and the field 1 mark of the track point between the two segments is updated to T. If it is greater than the time threshold, it will not be changed; the cumulative voyage within each VTS range is obtained according to the track points with field 1 of T in the VTS range.

[0022] Further, in step S3, spatial intersection determination is performed based on the cleaned trajectory point set and berth range data: to screen the trajectory points of the berthing and unberthing working conditions, the port ship operation trajectory points and trajectory points are used, and the sjoin module of the Geopandas package is used in Python to perform spatial intersection determination, and a new field 2 is added as an attribute of the trajectory point, and the intersection information is recorded in the AIS text data of field 2; the field 2 of the trajectory point within the berth range is marked as T, otherwise it is marked as F, in the AIS text data of the newly added field 2, the trajectory points are sorted according to the time sequence, and the AIS trajectory point is divided into multiple segments in sequence according to whether the field 2 of the trajectory point is marked as T or F, and the total berthing time Δt of each segment marked as T in and out of the berth is calculated for the field 2 of the trajectory point. If it is less than the time threshold, it is considered that the data recorded this time does not reflect the actual port stop process, and the port stop time is too short, and the field 2 mark of the trajectory point is updated to F. If it is greater than the time threshold, it is unchanged, and the port ship operation trajectory point is obtained according to the trajectory point whose field 1 is T within the VTS range.

[0023] Further, in step S4, the total carbon emissions of port cargo ships are calculated according to the cumulative voyage within each VTS range, including: extracting the EEOI value according to the maximum tonnage in the AIS data of port cargo ships and port ships, using the chemical tanker classification for ships transporting chemical liquids, and using the bulk carrier classification for solid bulk cargoes; calculating the carbon emissions of a single cargo ship from three perspectives: the lower quartile, the median estimate, and the upper quartile. The CO2 emissions of a single ship are calculated as follows:

[0024] CO2 emissions of a single ship = EEOI value * maximum tonnage * cumulative voyage within each VTS range

[0025] Further, in step S4, the total carbon emissions of the port-working ship are calculated according to the port-working ship operation trajectory points, including: dividing the carbon emissions of the port-working ship into two parts: among the trajectory points whose field 2 is T, the first trajectory point of the cargo ship entering the port is located in the berth and the speed is below 0.5m / s as point A, the last trajectory point entering the berth as point B, and point A and point B as the trajectory points of the tugboat operation;

[0026] The first trajectory point of the departing cargo ship outside the berth with a speed above 0.5m / s is taken as point C, the last trajectory point leaving the berth is taken as point D, and points C and D are taken as the trajectory of the departing tugboat operation.

[0027] point

[0028] Calculate the distance from point B to point A as the port entry distance, and calculate the distance from point D to point C as the port departure distance.

[0029] Calculate carbon emissions from port inflows:

[0030] Total CO2 emissions from tugboats entering the port = total distance of port operations * port experience value * diesel CO2 emission coefficient

[0031] Calculate departure carbon emissions:

[0032] Total CO2 emissions from tugboats leaving the port = total distance of departure operations * empirical value of the departure port * diesel CO2 emission coefficient

[0033] The total carbon emissions of ships at port are obtained based on the carbon emissions entering the port and leaving the port.

[0034] Furthermore, the method further comprises step S5: for the total carbon emissions of cargo ships at the port, the STEAM model is

[0035] The basic formula:

[0036]

[0037] Among them, P n,main is the ship's main engine power, P n,main =kv 3 , EF n,mainbase , A LF,t It is the basic property of the ship's main engine and will not change. Therefore, the carbon emissions per unit distance of the ship are proportional to the fifth power of the ship's speed. The total carbon emissions of port cargo ships are distributed in a 1km*1km grid in proportion to the fifth power of the speed for visualization.

[0038] For the total carbon emissions of port-operating ships, the position of the last trajectory point entering and leaving the berth is retained and visualized.

[0039] In addition, the present invention also provides a carbon emission estimation system for port cargo ships and port-operating ships based on AIS, comprising:

[0040] Acquisition module: Acquisition of AIS data, VTS range data and berth range data of port cargo ships and port-operating ships;

[0041] Cleaning module: cleans track points according to AIS data of cargo ships and port vessels, and obtains a set of cleaned track points;

[0042] Classification module: obtain the cumulative voyage within each VTS range according to the set of trajectory points after cleaning and the VTS range data; obtain the port ship operation trajectory points according to the set of trajectory points after cleaning and the berth range data;

[0043] Calculation module: Calculate the total carbon emissions of port cargo ships based on the cumulative voyage within each VTS range; calculate the total carbon emissions of port ships based on the operation trajectory points of port ships.

[0044] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0045] The method first obtains the cumulative voyage within each VTS range according to the set of cleaned trajectory points and the VTS range data; obtains the port ship operation trajectory points according to the set of cleaned trajectory points and the berth range data; then calculates the total carbon emissions (unit: gram) of the port cargo ship according to the cumulative voyage within each VTS range; calculates the total carbon emissions (unit: gram) of the port ship according to the port ship operation trajectory points. The present invention avoids the high-cost real-time direct measurement of carbon emissions, and the present invention calculates the total carbon emissions of port cargo ships and the total carbon emissions of port ships respectively, and more comprehensively estimates the carbon emissions of the port. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a flow chart of the carbon emission estimation method for port cargo ships and port-working ships based on AIS as described in Example 1;

[0047] Figure 2 The visualization result of the total carbon emissions of the port cargo ships described in Example 2;

[0048] Figure 3 The visualization result of the total carbon emissions of the port-operating ships described in Example 2;

[0049] Figure 4 This is a framework diagram of the carbon emission estimation system for port cargo ships and port-operating ships based on AIS as described in Example 3; DETAILED DESCRIPTION

[0050] The drawings are for illustrative purposes only and should not be construed as limiting the present patent;

[0051] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0052] Embodiment 1:

[0053] This embodiment provides Figure 1 The carbon emission estimation method for port cargo ships and port-operating ships based on AIS is shown, including:

[0054] S1: Obtain AIS data, VTS range data and berth range data of port cargo ships and port-operating ships;

[0055] S2: Clean the track points according to the AIS data of the port cargo ships and port ships to obtain a set of cleaned track points;

[0056] S3: Obtain the cumulative voyage within each VTS range according to the set of trajectory points after cleaning and the VTS range data; obtain the port ship operation trajectory points according to the set of trajectory points after cleaning and the berth range data;

[0057] S4: Calculate the total carbon emissions of port cargo ships based on the cumulative voyage within each VTS section; calculate the total carbon emissions of port ships based on the operation trajectory points of port ships.

[0058] This embodiment first obtains the cumulative voyage within each VTS range based on the set of cleaned trajectory points and the VTS range data; obtains the port ship operation trajectory points based on the set of cleaned trajectory points and the berth range data; then calculates the total carbon emissions of port cargo ships based on the cumulative voyage within each VTS range; and calculates the total carbon emissions of port ships based on the port ship operation trajectory points. This embodiment avoids the high-cost real-time direct measurement of carbon emissions, and this embodiment calculates the total carbon emissions of port cargo ships and the total carbon emissions of port ships respectively, and more comprehensively estimates the carbon emissions of ports.

[0059] Embodiment 2:

[0060] This embodiment further discloses on the basis of the first embodiment:

[0061] In step S1, the AIS data of port cargo ships and port working vessels are text data stored based on the Maritime Mobile Service Identifier (MMSI), including static data and dynamic data, wherein the static data includes the length and maximum tonnage of the cargo ship; the dynamic data includes the position and speed of the cargo ship.

[0062] Dynamic data can be expressed as L = {A i |i=1,…,m}, m represents the number of ships; read the trajectory data information of a ship within a certain time range, and construct a ship trajectory set A with MMSI as the unique identifier. i = {I i,j |j=1,2,…,n}, where n is the number of ship trajectory points, I i,j ={t i,j ,lon i,j ,lat i,j ,v i,j} is a four-tuple, I i,j Indicates that the ship is at t i,j The trajectory point information at the time, lon i,j t i,j The longitude of the vessel at the moment, lat i,j t i,j The dimension of the ship at the moment, v i,j t i,j The speed at which the ship is travelling at a given moment.

[0063] In step S2, it includes: using distance and speed thresholds to eliminate abnormal trajectory points, and compressing the trajectory points, specifically:

[0064] S2.1: Calculate the trajectory points I at adjacent moments i,j with I i,j+1 The distance between i,j ,I i,j+1 ], the compression distance threshold is δ d , if d[I i,j ,I i,j+1 ]>δ d , keep I i,j+1 Otherwise, delete I i,j+1 ; The removal distance threshold is ε d , if d[I i,j ,I i,j+1 ]<ε d , keep I i,j+1 Otherwise, delete I i,j+1 ; The calculation method is:

[0065] dlon=lon i,j -lon i,j+1 , dlat = lat i,j -lat i,j+1 ,

[0066] a=sin(dlat / 2)*2+cos(lat i,j )*cos(lat i,j+1 )*sin(dlon / 2)*2

[0067] c=2*atan2(sqrt(a),sqrt(1-a))

[0068] d[I i,j ,I i,j+1 ]=R*c (R represents the radius of the earth)

[0069] S2.2: Calculate the trajectory points I at adjacent moments i,j with I i,j+1 Sailing speed difference v[I i,j ,I i,j+1 ], the speed threshold is δ v , if v[I i,j ,I i,j+1 ]<δ v , keep I i,j+1 Otherwise, delete I i,j+1 , the calculation formula is as follows:

[0070] v[I i,j ,I i,j+1 ]=abs(vi,j -v i,j+1 )

[0071] S2.3: Return to step S2.1 until all the track points of the ships are processed.

[0072] In step S3, the cumulative voyage within each VTS range is obtained based on the cleaned track point set and the VTS range data, and the sjoin module of the Geopandas package is used in Python to perform spatial intersection judgment: a new field 1 is added as an attribute of the track point, and the intersection information is recorded in the AIS text data of field 1. The field 1 of the track point within the VTS range is marked as T, otherwise it is marked as F; in the AIS text data of the newly added field 1, the track points are sorted in time order, and the AIS track point is divided into multiple segments in sequence according to whether the field 1 of the track point is marked as T or F. The time difference Δt between the two segments marked as T entering and exiting the VTS track is calculated. If it is less than the time threshold, the latter segment should be merged with the former segment to form a complete segment, and the field 1 mark of the track point between the two segments is updated to T. If it is greater than the time threshold, it will not be changed; the cumulative voyage within each VTS range is obtained based on the track points with field 1 of T in the VTS range.

[0073] In step S3, spatial intersection determination is performed based on the cleaned trajectory point set and berth range data: to screen the trajectory points of the berthing and unberthing working conditions, the port ship operation trajectory points and trajectory points are used, and the sjoin module of the Geopandas package is used in Python to perform spatial intersection determination, and a new field 2 is added as an attribute of the trajectory point, and the intersection information is recorded in the AIS text data of field 2; the field 2 of the trajectory point within the berth range is marked as T, otherwise it is marked as F, in the AIS text data of the newly added field 2, the trajectory points are sorted according to the time sequence, and the AIS trajectory point is divided into multiple segments in sequence according to whether the field 2 of the trajectory point is marked as T or F. For the field 2 of the trajectory point, the total berthing time Δt of each segment marked as T in and out of the berth is calculated. If it is less than the time threshold, it is considered that the data recorded this time does not reflect the actual port stop process, and the port stop time is too short. The field 2 mark of the trajectory point is updated to F. If it is greater than the time threshold, it is unchanged, and the port ship operation trajectory point is obtained according to the trajectory point whose field 1 is T within the VTS range.

[0074] In step S4, the total carbon emissions of port cargo ships are calculated based on the cumulative voyage within each VTS range, including: extracting the EEOI value based on the maximum tonnage in the AIS data of port cargo ships and port vessels, using the chemical tanker classification for ships transporting chemical liquids, and using the bulk carrier classification for solid bulk cargoes; calculating the carbon emissions of a single cargo ship from three perspectives: lower quartile, median estimation, and upper quartile. The CO2 emissions of a single ship are calculated as follows:

[0075] CO2 emissions of a single ship = EEOI value * maximum tonnage * cumulative voyage within each VTS range

[0076] In step S4, the total carbon emissions of the port-based vessel are calculated based on the port-based vessel operation trajectory points, including:

[0077] The carbon emissions of port-operating ships are divided into two parts: among the trajectory points whose field 2 is T, the first trajectory point of the incoming cargo ship is located inside the berth and the speed is below 0.5m / s as point A, the last trajectory point entering the berth is point B, and points A and B are used as the trajectory points of the tugboat operation; the first trajectory point of the outgoing cargo ship is located outside the berth and the speed is above 0.5m / s as point C, the last trajectory point leaving the berth is point D, and points C and D are used as the trajectory points of the outgoing tugboat operation.

[0078] Calculate the distance from point B to point A as the port entry distance, and calculate the distance from point D to point C as the port departure distance.

[0079] Calculate carbon emissions from port inflows:

[0080] Total CO2 emissions from tugboats entering the port = total distance of port operations * port experience value * diesel CO2 emission coefficient

[0081] Calculate departure carbon emissions:

[0082] Total CO2 emissions from tugboats leaving the port = total distance of departure operations * empirical value of the departure port * diesel CO2 emission coefficient

[0083] The total carbon emissions of ships at port are obtained based on the carbon emissions entering the port and leaving the port.

[0084] The step S5 is also included: for the total carbon emissions of cargo ships in the port, the basic formula of the STEAM model is:

[0085]

[0086] Among them, P n,main is the ship's main engine power, P n,main =kv 3 , EF n,mainbase , ALF,t It is the basic property of the ship's main engine and will not change. Therefore, the carbon emissions per unit distance of the ship are proportional to the fifth power of the ship's speed. The total carbon emissions of the port cargo ships are distributed in a 1km*1km grid in proportion to the fifth power of the speed and visualized. The results are as follows Figure 2 As shown;

[0087] For the total carbon emissions of the port-operating ships, the position of the last trajectory point entering and leaving the berth is retained and visualized. The results are as follows: Figure 3 shown.

[0088] This embodiment first obtains the cumulative voyage within each VTS range based on the set of cleaned trajectory points and the VTS range data; obtains the port ship operation trajectory points based on the set of cleaned trajectory points and the berth range data; then calculates the total carbon emissions of port cargo ships based on the cumulative voyage within each VTS range; and calculates the total carbon emissions of port ships based on the port ship operation trajectory points. This embodiment avoids the high-cost real-time direct measurement of carbon emissions, and this embodiment calculates the total carbon emissions of port cargo ships and the total carbon emissions of port ships respectively, and more comprehensively estimates the carbon emissions of ports.

[0089] Embodiment three:

[0090] This embodiment provides Figure 4 The AIS-based port cargo ship and port ship operation carbon emission estimation system shown is characterized by:

[0091] Acquisition module: Acquisition of AIS data, VTS range data and berth range data of port cargo ships and port-operating ships;

[0092] Cleaning module: cleans track points according to AIS data of cargo ships and port vessels, and obtains a set of cleaned track points;

[0093] Classification module: obtain the cumulative voyage within each VTS range according to the set of trajectory points after cleaning and the VTS range data; obtain the port ship operation trajectory points according to the set of trajectory points after cleaning and the berth range data;

[0094] Calculation module: Calculate the total carbon emissions of port cargo ships based on the cumulative voyage within each VTS range; calculate the total carbon emissions of port ships based on the operation trajectory points of port ships.

[0095] This embodiment first obtains the cumulative voyage within each VTS range based on the set of cleaned trajectory points and the VTS range data; obtains the port ship operation trajectory points based on the set of cleaned trajectory points and the berth range data; then calculates the total carbon emissions of port cargo ships based on the cumulative voyage within each VTS range; and calculates the total carbon emissions of port ships based on the port ship operation trajectory points. This embodiment avoids the high-cost real-time direct measurement of carbon emissions, and this embodiment refines the potential carbon emission process during the ship entering the port, and calculates the total carbon emissions of port cargo ships and port ships respectively, and more comprehensively estimates the carbon emissions of the port.

[0096] In summary, the embodiments of the present invention relate to the field of carbon emissions, and to a method and system for estimating carbon emissions from port cargo ships and port-based ship operations based on AIS. The method includes: obtaining AIS data, VTS range data, and berth range data of port cargo ships and port-based ships; cleaning track points according to the AIS data of port cargo ships and port-based ships to obtain a set of cleaned track points; obtaining the cumulative voyage within each VTS range according to the cleaned track point set and the VTS range data; obtaining the port-based ship operation track points according to the cleaned track point set and the berth range data; calculating the total carbon emissions of the port cargo ship according to the cumulative voyage within each VTS range; calculating the total carbon emissions of the port-based ship according to the port-based ship operation track points. The embodiment of the present invention first obtains the cumulative voyage within each VTS range according to the cleaned track point set and the VTS range data; obtains the port-based ship operation track points according to the cleaned track point set and the berth range data; then calculates the total carbon emissions of the port cargo ship according to the cumulative voyage within each VTS range; and calculates the total carbon emissions of the port-based ship according to the port-based ship operation track points. The embodiment of the invention avoids the high-cost direct real-time measurement of carbon emissions, and calculates the total carbon emissions of port cargo ships and port-operating ships respectively, and estimates the carbon emissions of the port more comprehensively. The system ultimately provides important technical support and decision-making basis for further optimizing the port ship entry path and tugboat operations, and achieving the goal of energy conservation and emission reduction.

[0097] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for estimating carbon emissions from port cargo ships and port-operating ships based on AIS, characterized in that: include: S1: Obtain AIS data, VTS range data and berth range data of port cargo ships and port-operating ships; S2: Clean the track points according to the AIS data of the port cargo ships and port ships to obtain a set of cleaned track points; S3: Obtain the cumulative voyage within each VTS range according to the set of trajectory points after cleaning and the VTS range data; obtain the port ship operation trajectory points according to the set of trajectory points after cleaning and the berth range data; S4: Calculate the total carbon emissions of port cargo ships based on the cumulative voyage within each VTS section; calculate the total carbon emissions of port ships based on the operation trajectory points of port ships.

2. The method for estimating carbon emissions of port cargo ships and port-operating ships based on AIS according to claim 1 is characterized in that: In step S1, the AIS data of port cargo ships and port working vessels are text data stored based on the Maritime Mobile Service Identifier (MMSI), including static data and dynamic data, wherein the static data includes the length and maximum tonnage of the cargo ship; the dynamic data includes the position and speed of the cargo ship.

3. The method for estimating carbon emissions of port cargo ships and port-operating ships based on AIS according to claim 2 is characterized in that: Dynamic data can be expressed as L = {A i |i=1,…,m}, m represents the number of ships; read the trajectory data information of a ship within a certain time range, and construct a ship trajectory set A with MMSI as the unique identifier. i = {I i,j |j=1,2,…,n}, where n is the number of ship trajectory points, I i,j ={t i,j ,lon i,j ,lat i,j ,v i,j } is a four-tuple, I i,j Indicates that the ship is at t i,j The trajectory point information at the time, lon i,j t i,j The longitude of the vessel at the moment, lat i,j t i,j The dimension of the ship at the moment, v i,j t i,j The speed at which the ship is travelling at a given moment.

4. The method for estimating carbon emissions of port cargo ships and port-operating ships based on AIS according to claim 3 is characterized in that: In step S2, it includes: using distance and speed thresholds to eliminate abnormal trajectory points, and compressing the trajectory points, specifically: S2.1: Calculate the trajectory points I at adjacent moments i,j with I i,j+1 The distance between i,j ,I i,j+1 ], the compression distance threshold is δ d , if d[I i,j ,I i,j+1 ]>δ d , keep I i,j+1 Otherwise, delete I i,j+1 ; The removal distance threshold is ε d , if d[I i,j ,I i,j+1 ]<ε d , keep I i,j+1 Otherwise, delete I i,j+1 ; The calculation method is: dlon=lon i,j -lon i,j+1 ,dlat=lat i,j -lat i,j+1 , a=sin(dlat / 2)*2+cos(lat i,j )*cos(lat i,j+1 )*sin(dlon / 2)*2 c=2*atan2(sqrt(a),sqrt(1-a)) d[I i,j ,I i,j+1 ]=R*c (R represents the radius of the earth) S2.2: Calculate the trajectory points I at adjacent moments i,j with I i,j+1 Sailing speed difference v[I i,j ,I i,j+1 ], the speed threshold is δ v , if v[I i,j ,I i,j+1 ]<δ v , keep I i,j+1 Otherwise, delete I i,j+1 , the calculation formula is as follows: v[I i,j ,I i,j+1 ]=abs(v i,j -v i,j+1 ) S2.3: Return to step S2.1 until all the track points of the ships are processed.

5. The method for estimating carbon emissions of port cargo ships and port-operating ships based on AIS according to claim 1 is characterized in that: In step S3, the cumulative voyage within each VTS range is obtained based on the cleaned track point set and the VTS range data, and the sjoin module of the Geopandas package is used in Python to perform spatial intersection judgment: a new field 1 is added as an attribute of the track point, and the intersection information is recorded in the AIS text data of field 1. The field 1 of the track point within the VTS range is marked as T, otherwise it is marked as F; in the AIS text data of the newly added field 1, the track points are sorted in time order, and the AIS track point is divided into multiple segments in sequence according to whether the field 1 of the track point is marked as T or F. The time difference Δt between the two segments marked as T entering and exiting the VTS track is calculated. If it is less than the time threshold, the latter segment should be merged with the former segment to form a complete segment, and the field 1 mark of the track point between the two segments is updated to T. If it is greater than the time threshold, it will not be changed; the cumulative voyage within each VTS range is obtained based on the track points with field 1 of T in the VTS range.

6. The method for estimating carbon emissions of port cargo ships and port-operating ships based on AIS according to claim 1 is characterized in that: In step S3, spatial intersection determination is performed based on the cleaned trajectory point set and berth range data: to screen the trajectory points of the berthing and unberthing working conditions, the port ship operation trajectory points and trajectory points are used, and the sjoin module of the Geopandas package is used in Python to perform spatial intersection determination, and a new field 2 is added as an attribute of the trajectory point, and the intersection information is recorded in the AIS text data of field 2; the field 2 of the trajectory point within the berth range is marked as T, otherwise it is marked as F, in the AIS text data of the newly added field 2, the trajectory points are sorted according to the time sequence, and the AIS trajectory point is divided into multiple segments in sequence according to whether the field 2 of the trajectory point is marked as T or F. For the field 2 of the trajectory point, the total berthing time Δt of each segment marked as T in and out of the berth is calculated. If it is less than the time threshold, it is considered that the data recorded this time does not reflect the actual port stop process, and the port stop time is too short. The field 2 mark of the trajectory point is updated to F. If it is greater than the time threshold, it is unchanged, and the port ship operation trajectory point is obtained according to the trajectory point whose field 1 is T within the VTS range.

7. The method for estimating carbon emissions from port cargo ships and port-operating ships based on AIS according to claim 2 is characterized in that: In step S4, the total carbon emissions of port cargo ships are calculated based on the cumulative voyage within each VTS range, including: extracting the EEOI value based on the maximum tonnage in the AIS data of port cargo ships and port vessels, using the chemical tanker classification for ships transporting chemical liquids, and using the bulk carrier classification for solid bulk cargoes; calculating the carbon emissions of a single cargo ship from three perspectives: lower quartile, median estimation, and upper quartile. The CO2 emissions of a single ship are calculated as follows: CO2 emissions of a single ship = EEOI value * maximum tonnage * accumulated voyage within each VTS range.

8. The method for estimating carbon emissions of port cargo ships and port-operating ships based on AIS according to claim 6 is characterized in that: In step S4, the total carbon emissions of port-based ships are calculated based on the trajectory points of port-based ships, including: dividing the carbon emissions of port-based ships into two parts: among the trajectory points whose field 2 is T, the first trajectory point of the incoming cargo ship's trajectory point is located inside the berth and has a speed below 0.5 m / s as point A, the last trajectory point entering the berth is point B, and points A and B are used as the trajectory points of the tugboat operation; the first trajectory point of the outgoing cargo ship's trajectory point is located outside the berth and has a speed above 0.5 m / s as point C, the last trajectory point leaving the berth is point D, and points C and D are used as the trajectory points of the outgoing tugboat operation. Calculate the distance from point B to point A as the port entry distance, and calculate the distance from point D to point C as the port departure distance. Calculate carbon emissions from port inflows: Total CO2 emissions of tugboats entering the port = total distance of port operations * empirical value of the port of entry * diesel CO2 emission coefficient Calculation of carbon emissions leaving the port: Total CO2 emissions from departing tugboats = total distance of departure operations * empirical value of the departure port * diesel CO2 emission coefficient. The total carbon emissions of port-operating ships are obtained based on the carbon emissions entering the port and leaving the port.

9. The method for estimating carbon emissions of port cargo ships and port-operating ships based on AIS according to claim 1 is characterized in that: The step S5 is also included: for the total carbon emissions of cargo ships in the port, the basic formula of the STEAM model is: Among them, P n,main is the ship's main engine power, P n,main =kv 3 , EF n,mainbase , A LF,t It is the basic property of the ship's main engine and will not change. Therefore, the carbon emissions per unit distance of the ship are proportional to the fifth power of the ship's speed. The total carbon emissions of port cargo ships are distributed in a 1km*1km grid in proportion to the fifth power of the speed for visualization. For the total carbon emissions of port-operating ships, the position of the last trajectory point entering and leaving the berth is retained and visualized.

10. AIS-based carbon emission estimation system for port cargo ships and port-operating ships, characterized by: include: Acquisition module: Acquisition of AIS data, VTS range data and berth range data of port cargo ships and port-operating ships; Cleaning module: cleans track points according to AIS data of cargo ships and port vessels, and obtains a set of cleaned track points; Classification module: obtain the cumulative voyage within each VTS range according to the set of trajectory points after cleaning and the VTS range data; obtain the port ship operation trajectory points according to the set of trajectory points after cleaning and the berth range data; Calculation module: Calculate the total carbon emissions of port cargo ships based on the cumulative voyage within each VTS range; calculate the total carbon emissions of port ships based on the operation trajectory points of port ships.

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