Ship route tidal window passage calculation method and system

Abstract

The invention relates to the field of intelligent shipping, in particular to a ship route tidal window passage calculation method and system, and the method comprises the steps: obtaining the navigation parameters of a ship and the hydrological geographic information of a target route; calculating the minimum safe water depth required by the ship in the sailing process based on the sailing parameters; predicting the tidal height change of at least one tidal point on the target route in a period of time in the future based on the hydrological geographic information; the actual water depth change of the tidal point in a period of time in the future is dynamically determined in combination with the tidal height change and hydrological geographic information; performing comparative analysis on the actual water depth change and the minimum safe water depth, and generating one or more passable time windows of the tidal point according to an analysis result; and outputting a passable time window for ship navigation decision. According to the method, multiple factors such as ship sinkage, waves, ship swing and safety reserve are comprehensively considered, the dynamically calculated minimum safety water depth is more scientific and comprehensive, and risks possibly brought by fixed safety margin are avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of intelligent shipping, in particular to a ship route tidal window passing calculation method and system. BACKGROUND

[0002] When a ship passes through a restricted waterway such as a near-shore shallow water area, an estuary, a canal, etc., it must accurately calculate the tidal window to ensure that the ship has a sufficient water depth greater than a safety threshold, so as to avoid grounding accidents. The periodic change in water depth caused by tides is a key factor in determining the time window that can be passed. Currently, existing passing calculation methods mainly rely on the following methods: crew members or shore-based dispatch personnel use official published tide prediction tables, combined with fixed parameters such as ship static draft, chart water depth, etc., to estimate the time period that can be passed through by manual calculation. Some slightly more advanced systems can integrate tide prediction data to achieve simple "chart water depth + tidal height ≥ ship draft + fixed safety margin" automatic calculation.

[0003] However, the existing technology relies on static and outdated data, especially the chart reference water depth. The chart update cycle is long and cannot reflect the real-time changes of the seabed topography in the estuary and siltation area. The system uses one possibly inaccurate basic data for calculation, and the "safety window" output by it may actually hide the risk of grounding. Since it relies on static data, it will be difficult to handle the dramatic impact of dynamic environmental factors such as storm surges on water depth, further exacerbating the unreliability of its calculation results. Secondly, the existing solution is essentially a one-way, deterministic calculation tool. It assumes that the input data is completely accurate and outputs a seemingly certain result. When the calculation conditions are in a critical state or the data is unreliable (which is often the case in actual navigation), the system either cannot pass or can only provide an unverified "optimistic" window, and cannot quantify the risk therein. It forces the crew to rely heavily on personal experience for judgment, which is not only inefficient, but also prone to accidents due to lack of experience or misjudgment.

[0004] Therefore, the existing technology has defects and needs to be improved. SUMMARY

[0005] In order to solve one or several problems in the prior art, the main purpose of the present application is to provide a ship route tidal window passing calculation method and system.

[0006] In order to achieve the above-mentioned purpose of the application, the present application provides a ship route tidal window passing calculation method, which comprises:

[0007] Obtaining the navigation parameters of the ship and the hydrographic information of the target route;

[0008] Based on the navigation parameters, calculating the minimum safety water depth required by the ship during navigation;

[0009] predict a tidal height change of at least one tidal point on the target route in a future period of time based on the hydrographic information;

[0010] determine an actual water depth change of the tidal point in the future period of time dynamically by combining the tidal height change and the hydrographic information;

[0011] perform comparison analysis on the actual water depth change and the minimum safe water depth, and generate one or more passable time windows of the tidal point according to an analysis result;

[0012] output the passable time windows for use in ship navigation decision-making.

[0013] Embodiments of the present application also provide a ship route tidal window passing calculation system, comprising:

[0014] an acquisition module configured to acquire a ship navigation parameter and hydrographic information of a target route;

[0015] a calculation module configured to calculate a minimum safe water depth required by the ship in a navigation process based on the navigation parameter;

[0016] a prediction module configured to predict a tidal height change of at least one tidal point on the target route in a future period of time based on the hydrographic information;

[0017] a combination module configured to determine an actual water depth change of the tidal point in the future period of time dynamically by combining the tidal height change and the hydrographic information;

[0018] an analysis module configured to perform comparison analysis on the actual water depth change and the minimum safe water depth, and generate one or more passable time windows of the tidal point according to an analysis result;

[0019] an output module configured to output the passable time windows for use in ship navigation decision-making.

[0020] The present application also provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements steps of the method according to any one of the preceding embodiments when executing the computer program.

[0021] The present application also provides a computer readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement steps of the method according to any one of the preceding embodiments.

[0022] The ship route tidal window passing calculation method and system of the embodiment of the application, through integrating ship static and dynamic parameters, chart hydrographic data and tidal prediction information, the system automatically completes dynamic calculation of the minimum safe water depth, simulation of the future actual water depth and safety condition comparison, solves the traditional mode of relying on the experience of the crew to manually check the table and estimate, and significantly improves the calculation efficiency and accuracy. Secondly, the safety of ship navigation in shallow water is improved. The present application comprehensively considers multiple factors such as ship sinking amount, wave, ship swing and safety reserve, and the dynamically calculated minimum safe water depth is more scientific and comprehensive, avoiding the risk that may be caused by the fixed safety margin. The generated passing window is based on the accurate water depth condition judgment, and the probability of grounding accidents caused by insufficient water depth is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The flowchart of the ship route tidal window passing calculation method of an embodiment of the application is shown in the figure.

[0024] Figure 2 The flowchart of the ship route tidal window passing calculation method of an embodiment of the application is shown in the figure.

[0025] Figure 3 The structural schematic block diagram of the ship route tidal window passing calculation system of an embodiment of the application is shown in the figure.

[0026] Figure 4 The structural schematic block diagram of the computer device of an embodiment of the application is shown in the figure.

[0027] The implementation, functional features and advantages of the application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the application more clear, the application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the application and not to limit the application.

[0029] Referring to Figure 1 , an embodiment of the application provides a ship route tidal window passing calculation method, which comprises:

[0030] S1, obtaining the navigation parameters of a ship and the hydrographic information of a target route;

[0031] S2, calculating the minimum safe water depth required by the ship during navigation based on the navigation parameters;

[0032] S3, predicting the tidal height change of at least one tidal point on the target route in a future period of time based on the hydrographic information;

[0033] S4, dynamically determine the actual water depth change of the tidal point in the future period of time in combination with the tidal height change and the hydrographic information;

[0034] S5, compare and analyze the actual water depth change with the minimum safe water depth, and generate one or more passable time windows of the tidal point according to the analysis result;

[0035] S6, output the passable time window for ship navigation decision-making.

[0036] As described in steps S1-S3 above, information is collected in real time or quasi-real time from data sources such as the Automatic Identification System (AIS), ship database, Electronic Chart Display and Information System (ECDIS), etc. through the interface. The object of calculation is clearly defined (which ship, which route). Provide necessary input parameters for all subsequent calculation modules. Realize the automatic process driven by data, liberate the crew from the tedious work of manual searching and inputting various parameters, provide "raw materials" for the automatic operation of the whole system, and ensure the pertinence and accuracy of the calculation results. The minimum safe water depth (h_min) is not a fixed value, but a dynamic value that changes with the state of the ship (such as speed) and the environment (such as water depth). Its core calculation is to consider the sinking amount (Squat) generated during ship navigation and the Under Keel Clearance (UKC) required to deal with uncertain factors such as waves and sway. Scientifically and dynamically determine the water depth threshold required for a specific ship to safely pass in a specific navigation state. Convert the physical characteristics and safety specifications of the ship into a quantifiable value that can be compared with the environmental water depth. Avoid the problem of over-conservatism or risk-taking that may be caused by using a fixed safety margin in traditional methods. Make the safety standard personalized and precise, which is a key technical link to improve the efficiency and safety of navigation. Use celestial mechanics and oceanography principles (such as the harmonic constant method) to predict the periodic change of future tides according to the latitude and longitude of the tidal point. The tidal height (t(t)) is a function of time (t). Obtain the predicted data of how the external environment (water depth) changes over time in the future period of time. Provide key time series input for calculating "actual water depth". Convert the uncontrollable natural environmental factors into predictable and quantifiable time series data, which makes it possible to determine "when the water depth is sufficient" in the future.

[0037] The simulation reconstruction of the navigation environment is performed as described in steps S4-S6. At any time t, the actual water depth (h(t)) of a point is equal to the static chart datum water depth (h0) plus the dynamic tidal height (t(t)), i.e. h(t) = h0 + t(t). Through this formula, the static geographic information is fused with the dynamic prediction information. The real available water depth at each future time is calculated. A bridge connecting the ship's own conditions (minimum safe water depth) and the external environment (actual water depth) is built. A continuous actual water depth curve bound to the time axis is generated, which provides a baseline for the next step of comparison and analysis. For each time point t, if h(t) >= h_min, the time is navigable. All continuous time periods that meet this condition are found and combined, i.e. a "navigable time window" is formed. The conversion from "data" to "conclusion" is automatically completed. All potential navigation periods that meet the safety conditions are accurately found. The automation and precision of the navigation window discovery are realized, replacing the outdated manual estimation method relying on the experience of the crew. The calculation results are presented to the end user (captain or dispatcher) in a clear and intuitive form (such as a list or chart). The "calculation" to "application" is completed. The technical achievements can serve practical decision-making, improving the scientificity and efficiency of decision-making, and ultimately achieving the goal of ensuring safety and optimizing operation.

[0038] As described above, by integrating the static and dynamic parameters of the ship, the chart hydrographic data and the tidal prediction information, the system automatically completes the dynamic calculation of the minimum safe water depth, the simulation of the future actual water depth and the comparison of the safety conditions, solves the traditional method of relying on the experience of the crew to manually look up and estimate, significantly improves the calculation efficiency and accuracy. Secondly, the safety of ship navigation in shallow water is improved. The present application comprehensively considers the factors such as ship sinking amount, wave, ship rolling and safety reserve, and the dynamically calculated minimum safe water depth is more scientific and comprehensive, avoiding the risks that may be caused by the fixed safety margin. The generated navigation window is based on the accurate water depth condition judgment, reducing the probability of grounding accidents caused by insufficient water depth.

[0039] In one embodiment, the navigation parameters include static parameters and dynamic parameters of the ship; the static parameters at least include the ship's full load draft, and the dynamic parameters at least include the ship's speed; the hydrographic information at least includes the chart datum water depth of the tidal point in the route; and the steps of calculating the minimum safe water depth required by the ship include:

[0040] According to the ship speed and the chart datum water depth, the sinking amount formula is used to calculate the sinking amount of the ship during navigation due to the ship's displacement effect and wave action;

[0041] Based on the sinking amount, the total reserve water depth is calculated by combining the wave reserve water depth, the ship rolling reserve water depth and the safety reserve water depth;

[0042] The minimum safe water depth is obtained by adding the ship's full load draft, the sinking amount and the total residual water depth;

[0043] The formula for calculating the sinking amount is: Wherein, k is a coefficient related to the type of ship, A is the underwater cross-sectional area of the ship body, h is the current water depth, and v is the ship speed;

[0044] The formula for calculating the total residual water depth is: F=Δd+F1+F2+F3, wherein F1 is the wave residual water depth, which is 1 / 2 of the estimated wave height; F2 is the ship rolling residual water depth, which is 1 / 20 of the ship width; F3 is the safety reserve water depth determined according to the channel grade.

[0045] As described above, the navigation parameters include static parameters and dynamic parameters of the ship; the static parameters at least include the ship's full load draft (d0), and the dynamic parameters at least include the ship's speed (V); the hydrographic geographic information at least includes the chart datum depth (h0) of the tidal point in the route. Static parameters: represent the inherent and infrequently changing physical characteristics of the ship. Full load draft (d0) is the absolute reference for calculating water depth requirements. Dynamic parameters: represent the real-time motion state of the ship. Speed (V) is the key input for calculating the sinking amount (Δd), and the sinking amount is the core of the dynamic safety water depth. Hydrographic geographic information: Chart datum depth (h0) is the static basis for calculating the actual water depth. Precise input of the calculation model is realized. By limiting these minimum necessary parameter sets, it is ensured that the system can complete the core functions on the premise of the most concise and most operable data requirements, avoiding system complexity or data acquisition difficulties caused by too many parameters. "Static draft + dynamic draft increment + environmental safety margin". Calculate the sinking amount (Δd): The principle is that when the ship sails in shallow water, the interaction between the ship body and the river bed / sea bed causes the water flow to accelerate and the pressure to decrease, thereby causing the ship body to sink. The faster the speed (V), the shallower the water depth (h), and the more significant the sinking effect. This step quantifies the effective draft increase caused by the motion behavior of the ship itself. Calculate the total residual water depth (F): The principle is that there are uncertainties in the navigation environment, and a buffer space must be reserved for these risks. F1 (wave residual water depth): Compensate for the water surface fluctuation caused by waves to avoid the ship touching the bottom when it is in the trough. F2 (ship rolling residual water depth): Compensate for the additional space required for the downward movement of the ship's bilge (the curved part connecting the bottom and the side of the ship) when the ship rolls laterally / vertically due to wind and waves. F3 (safety reserve water depth): Compensate for unexpected factors such as chart errors and mild siltation, which is the last safety barrier. This step quantifies the safety buffer required to respond to external environmental risks. Synthesize the minimum safe water depth (h min ): Add all the above components: h min= d0+Δd+F. This formula integrates the three factors of the ship itself, ship movement and environmental risk, and obtains a comprehensive, scientific and dynamic safety standard. Compared with the traditional method of using a fixed value (such as 0.5 meters or 1 meter) as a safety margin, the h min This method dynamically calculates h min may be smaller than the traditional method using a fixed large margin, thereby revealing a longer passable window, reducing unnecessary waiting time of the ship, and improving operational efficiency. The sinking amount formula: accurately depicts the physical relationship between the speed (V), ship type (reflected by k and A), and water depth (h). The excess water depth formula: clearly defines the composition and value method of each component of the total excess water depth (such as F1 taking 1 / 2 of the wave height, and F2 taking 1 / 20 of the ship width), digitizes and standardizes the empirical rules in navigation practice. Automation and standardization of calculation are achieved. Clear calculation rules are provided, so that different users using the system can obtain consistent results, eliminating the subjectivity and errors brought by manual experience judgment, and ensuring the repeatability and reliability of the patent scheme.

[0046] In an embodiment, the step of predicting the tidal height change of at least one tidal point on the target route in a future period of time based on the hydrographic geographic information comprises:

[0047] Obtaining the longitude and latitude coordinates of each tidal point on the target route;

[0048] Based on the longitude and latitude coordinates of the tidal points, calling a tidal prediction model to calculate the tidal height of each time point in a future set period of time through the tidal prediction model;

[0049] The tidal prediction model is the harmonic constant method, and the tidal height calculation formula is: wherein H0 is the average sea level height, H i is the amplitude of the i-th component tide, ω i is the angular frequency of the i-th component tide, is the initial phase of the i-th component tide, and t is time.

[0050] As mentioned above, the tide phenomenon is essentially the response of the Earth's oceans to the tidal forces exerted by celestial bodies. The characteristics of tides (such as the height of the tide, the time of the tide) at different geographical locations are very different, which is determined by factors such as the latitude and longitude of the point, the seafloor topography, the shape of the coastline, etc. The latitude and longitude coordinates are the most critical index to determine the tide characteristics of a location. The system makes it possible to provide independent and customized tide forecasts for each point by obtaining the coordinates of the key nodes on the route. It ensures that the tide forecast is not a general prediction for a vast area, but an accurate point-by-point forecast for the points on the route. This is the primary guarantee of the accuracy of the calculation results. For a winding route, the tide times at different locations can be very different. This feature enables the system to establish a tide model for each key point on the route, which is the basis for subsequent "correlation window" calculations. The system has a pre-installed or accessible database containing global or regional tide data. When a specific latitude and longitude is input, the system will call the tide model parameters corresponding to the location, then run the model algorithm to calculate the tide height at each future time (e.g. every minute or hour). This is an automated process of "input location > call model > output time series". The crew is completely liberated from the tedious task of consulting paper tide tables and manually interpolating tide heights and times. Instead of discrete time points (such as high tide and low tide times), a continuous tide height curve t(t) is output, which accurately corresponds to the time axis. This provides an indispensable data foundation for subsequent high-frequency and high-precision water depth comparisons. The principle of the harmonic constant method is that any complex tide at a location can be mathematically decomposed into the superposition of multiple regular astronomical constituents (such as the main lunar semidiurnal constituent M2 caused by the moon's gravity, the main solar semidiurnal constituent S2 caused by the sun's gravity, etc.). Each constituent has its own amplitude (H i , representing the influence of the constituent), angular frequency (ω i , representing the period of the constituent) and initial phase ( representing the initial state of the constituent). H0 (mean sea level height): is the reference surface for calculation. The summation formula represents the sum of the contributions of all constituents to the total water level at time t. For any given location, a complete set of (H i , ω i , ) parameters is called the "harmonic constant" of the location, which is obtained by fitting long-term observation data and can be used for future prediction once determined.

[0051] Referring to Figure 2 , in an embodiment, the step of comparing and analyzing the actual water depth change with the minimum safe water depth, and generating one or more passable time windows for the tide point according to the analysis result, comprises:

[0052] S51. When the target route contains only one tidal point, calculate the actual water depth of the tidal point over a future period of time.

[0053] S52. Based on the calculation results, the actual water depth at each moment is compared with the minimum safe water depth, and all moments that satisfy the condition that the actual water depth is greater than or equal to the minimum safe water depth are selected.

[0054] S53. Based on the filtering results, merge the time periods to which the consecutive times that meet the conditions are located to generate one or more consecutive passable time windows for the tidal point.

[0055] As described above, the system superimposes the time-varying tide height data t(t) output by the tide height prediction module with the static nautical chart reference water depth h0 at that point on a time-by-time basis, i.e., h(t) = h o +t(t) generates a new continuous curve h(t) representing the true water depth at every future moment of that point. This transforms the environmental prediction data into a "water depth simulation timeline" that can be directly used for safety analysis. This curve forms the basis for all subsequent judgments, transforming the complex navigation condition problem into a quantifiable water depth data problem that varies over time. Along the time axis, a judgment operation is performed at an extremely high frequency (e.g., every minute or every second), marking moments that meet the conditions as "passable". This is a fully automated, high-precision scanning process that traverses the entire future time period (e.g., 72 hours) without omission, ensuring that all possible safe moments are identified. After the previous step, a set of numerous discrete "passable moments" is obtained. The algorithm in this step scans this set, identifies all consecutive time segments, and merges each consecutive segment into an independent "passable time window". For example, consecutive time points such as "02:00, 02:01, 02:02, ..., 08:59, 09:00" can be combined and represented as a single window "[02:00-09:00]". This aggregates thousands of discrete data points into several "time intervals" with clearly defined start and end times that are easy for humans to understand and use. This is a crucial leap from "computation" to "usability". Crew members need to know "from what time to what time" they can pass through, not "from hundreds of time points". Defining the continuity and number of windows ("one or more") provides a basis for subsequent possible multi-window optimization (such as selecting the longest window or the window for daytime passage).

[0056] In one embodiment, the step of comparing and analyzing the actual water depth change with the minimum safe water depth, and generating one or more passable time windows for the tidal point based on the analysis results, further includes:

[0057] when the target route contains multiple continuous tidal points, obtaining a sailing speed of the ship;

[0058] according to the sailing speed, calculating a predicted sailing time of the ship between two adjacent tidal points;

[0059] according to the calculation result, determining a passable time window of one tidal point and the predicted sailing time required to go to the next tidal point;

[0060] based on the passable time window of the one tidal point and the predicted sailing time required to go to the next tidal point, inferring and determining an associated passable time window of the next tidal point.

[0061] As mentioned above, the system, when performing the calculation, will judge the structure of the current route being processed. When it identifies that the route contains a series of tidal points that need to be passed through consecutively (such as multiple shallow points on an approach channel), the system will automatically enter a more advanced analysis mode. In this mode, the system will proactively obtain the current or planned sailing speed of the ship. The sailing speed here represents the ability of the ship to move quickly between points and is a key input for calculating the time cost. The calculation mode can be automatically switched according to the complexity of the route, and the most core dynamic parameters are prepared for subsequent correlation analysis. The system knows the geographical distance between the two adjacent tidal points. By dividing this distance by the sailing speed of the ship, the system can calculate the approximate time it takes for the ship to travel from leaving the first point to arriving at the next point. This process essentially converts the spatial distance into a time delay. It achieves the conversion from static geographical information to dynamic time planning. It provides the crucial information of "how long does it take for the ship to go from point A to point B", which lays a solid foundation for the next step of determining whether the ship can pass through two points consecutively. Use a "relay race" metaphor to understand: time window shift: assume the ship departs from the first tidal point (point A) within a certain allowed passage time period. Then, the time range for it to arrive at the next tidal point (point B) is a new time range obtained by delaying the departure time from point A by a "sailing time". Time window matching: point B itself also has an original time range that it allows passage according to the water depth conditions. Instead of directly using this original range, the system performs a key operation: comparing the time range obtained by "shifting" in the previous step with the original passage time range of point B itself to find the overlapping part of the two. Generation of correlation window: this overlapping common time is the passage time window that the ship can actually use effectively at point B and is associated with the passage time period of point A. If no overlap is found, it means that the ship cannot arrive at point B on time and safely from the departure window at point A. The system will automatically try other passage windows at point A until it finds a safe passage for the entire route that seamlessly connects all nodes in time. It solves the core problem of route connectivity: it ensures that the system does not recommend a time point that can cause the ship to be stranded in the middle of the route, but a complete and feasible navigation plan that is globally coherent. Crew members only need to follow this plan to safely navigate the entire complex route. It proactively avoids significant safety risks that can be caused by ignoring the sailing time between points. At the same time, it can intelligently dig out the most optimized and efficient passage time sequence to save valuable waiting time for ship scheduling.

[0062] In an embodiment, after the step of outputting the passable time window for use in ship navigation decision making, the method further comprises:

[0063] establishing a historical transit database associated with the target route, the database recording actual transit data of other vessels passing through each tidal point on the route, the actual transit data including at least actual draft of the vessel and passing time;

[0064] performing a reverse depth verification based on the historical transit database, the steps including: for a specific tidal point, retrieving vessel data passing through the point at a known tidal height time, and according to actual draft of the vessel and navigation parameters of the vessel, reversely calculating actual depth of the point at the transit time;

[0065] comparing the reversely calculated actual depths with the chart reference depth, and generating a depth confidence assessment result of the tidal point;

[0066] in response to the depth confidence assessment result being lower than a preset threshold, generating alert information about reliability of the chart reference depth of the tidal point, and suggesting to use a corrected safe depth value for transit window calculation.

[0067] As mentioned above, a huge database of background information is continuously and automatically collected after each calculation. This database specifically records the actual performance of other vessels in real navigation, the core content includes: a specific time, a specific location on the route, and the actual draft of a ship at that time. Upgrade the system from a one-time calculation tool to a learning platform that continuously accumulates knowledge. It turns every past ship into a mobile information collection point, providing the system with first-hand big data reflecting the real conditions of the channel. A ship can safely pass a point at a certain time, so the water depth at that point must be sufficient. For any record in the database, the system knows two certain information: the exact time the ship passed the point, and the actual draft of the ship at that time. According to the exact time of passing, the system can query the tide model to accurately know the tide height at that time. Then, the system performs a reverse calculation: since the ship can safely pass, it means that the total water depth at that time is at least equal to the draft of the ship plus a safety margin. Subtract the "tide height at that time" from the "total water depth" calculated to find out how much the "actual seabed depth" at that point is. Instead of sending professional surveying ships, it cleverly uses routine navigation ships as "volunteer surveyors" to continuously verify and record actual changes in seabed topography. Retrieve a large number of reverse calculation records for the same location, and compare and analyze these calculated "actual seabed depths" with the official reference depth marked on the chart. If a large number of calculation results are very close to the chart data, the chart is reliable, and the system has high "confidence" in this point (high confidence). If the calculation results are generally, continuously shallower or deeper than the chart depth, or the results are very chaotic and differ greatly, the chart data may be outdated, or the terrain in this area is extremely unstable, and the system's "confidence" in this point will be reduced (low confidence). It can intelligently assess whether these data themselves are reliable and give a quantitative "credibility" score. When the chart data for a certain location is found to be of low credibility through the above analysis, take proactive action. Immediately send clear warning information to the user, indicating that "the chart reference depth at this location may be inaccurate", clearly revealing the potential risks. Suggest using a "corrected depth" value calculated based on a large amount of historical data that is more in line with the current actual situation to recalculate the passage window, so as to get a safer and more reliable result. It can effectively prevent decision-making errors caused by using incorrect and outdated chart data, providing double protection for navigation safety.

[0068] In an embodiment, the performing reverse depth verification based on the historical passage database further comprises:

[0069] The credibility of each record in the historical navigation database is evaluated according to the type of the data source ship, the positioning accuracy of the ship, and the acquisition method of the actual draft data of the ship in the record.

[0070] According to the credibility evaluation result, a credibility weight is given to each data record.

[0071] When the actual depth at the point is calculated by back-stepping, a weighted average algorithm based on the credibility weight is used for calculation.

[0072] When there is a significant conflict between the multiple sets of actual depth values obtained by back-stepping calculation, the result of the high credibility weight data set is preferred, and an abnormal marking and review process of the low credibility data set is triggered.

[0073] As mentioned above, not all the data reported by ships are equally accurate. Therefore, before using any data, the system will first score its "credibility". The evaluation criteria include: the type of the data source ship: for example, the data of a professional ocean survey ship is much more authoritative and accurate than that of a common cargo ship. The data of research vessels and channel maintenance vessels are the most reliable. The positioning accuracy of the ship: the accuracy of the ship's GPS and other navigation equipment is different. The system can identify the positioning error of the data source (such as the accuracy identifier in the AIS information), and the data with higher positioning accuracy is more reliable. The way the actual draft data of the ship is obtained: is it automatically collected by high-precision sensors installed on the ship, or is it manually input by the crew? Obviously, automatically collected data is more reliable, avoiding the possibility of human error. The "survival of the fittest" of the original data is realized. The system no longer treats all data equally, but can distinguish the "background" and "quality" of the data like an experienced analyst, laying a solid and reliable data foundation for subsequent high-precision calculations. The result of the above evaluation is a qualitative judgment, and this step quantifies it into an operational weight value. The system will assign a weight coefficient to each data record, for example, the weight of high-precision data automatically collected by a professional survey ship is 1.0, while the weight of data manually reported by a common cargo ship may only be 0.6. The qualitative judgment of data quality is converted into a quantified parameter that can be used in mathematical calculations. This provides a direct basis for the next step of weighted calculation, so that high-quality data can have a greater influence on the final result. When performing reverse depth verification calculations, the system no longer uses simple arithmetic averaging, but uses "weighted averaging". This means that a high-credibility data with a weight of 1.0 has twice the influence on the final calculation result as a low-credibility data with a weight of 0.5. The final reverse-pushed depth value is more determined by high-quality, high-precision data, effectively suppressing the interference of low-quality data, noise data, or even incorrect data on the result. The result of the weighted average is more scientific and reliable than the simple average, and can better reflect the actual depth of the channel. When the system finds that multiple sets of water depth values calculated for the same location contradict each other (for example, some data calculates that the water depth is sufficient, while others calculate that the water depth is insufficient), it will not simply mix them together or take the average, but will start an intelligent conflict resolution process: at the same time, for low-weight data that contradicts the conclusion of high-weight data, it will be marked as "abnormal data" and trigger a review process. Prompt the administrator to perform manual review, or exclude it from subsequent calculations to prevent it from polluting the database. Properly handle the inevitable data conflict problem in the real world to ensure the stability of the system output. By marking abnormal data, it provides a target for later manual intervention and data cleaning, which helps to continuously optimize the quality of the entire historical database.

[0074] Reference Figure 3The ship route tidal window passing calculation system provided in the embodiments of the present application comprises:

[0075] The acquisition module 1 is configured to acquire a navigation parameter of a ship and hydrographic information of a target route.

[0076] The calculation module 2 is configured to calculate a minimum safe water depth required by the ship during navigation based on the navigation parameter.

[0077] The prediction module 3 is configured to predict a tidal height change of at least one tidal point on the target route within a future period of time based on the hydrographic information.

[0078] The combination module 4 is configured to dynamically determine an actual water depth change of the tidal point within the future period of time by combining the tidal height change and the hydrographic information.

[0079] The analysis module 5 is configured to compare and analyze the actual water depth change and the minimum safe water depth, and generate one or more passable time windows of the tidal point according to an analysis result.

[0080] The output module 6 is configured to output the passable time window for use in ship navigation decision-making.

[0081] As described above, it can be understood that each component of the ship route tidal window passing calculation system provided in the present application can realize the function of any one of the ship route tidal window passing calculation methods described above, and the specific structure will not be described again.

[0082] Reference Figure 4 The computer device provided in the embodiments of the present application can be a server, and the internal structure thereof can be as shown in Figure 4 The computer device comprises a processor, a memory, a network interface and a database connected through a system bus. The processor of the computer device is configured to provide calculation and control capabilities. The memory of the computer device comprises a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium. The database of the computer device is configured to store monitoring data and other data. The network interface of the computer device is configured to communicate with an external terminal through a network connection. The computer program is executed by the processor to implement a ship route tidal window passing calculation method.

[0083] The processor executes the ship route tidal window passing calculation method, and the ship route tidal window passing calculation method comprises the following steps: acquiring navigation parameters of a ship and hydrographic information of a target route; calculating a minimum safe water depth required by the ship in a navigation process based on the navigation parameters; predicting tidal height changes of at least one tidal point on the target route in a future period of time based on the hydrographic information; dynamically determining actual water depth changes of the tidal point in the future period of time in combination with the tidal height changes and the hydrographic information; comparing and analyzing the actual water depth changes and the minimum safe water depth, and generating one or more passable time windows of the tidal point according to an analysis result; and outputting the passable time windows for use in ship navigation decision-making.

[0084] An embodiment of the present application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement a ship route tidal window passing calculation method, and the ship route tidal window passing calculation method comprises the following steps: acquiring navigation parameters of a ship and hydrographic information of a target route; calculating a minimum safe water depth required by the ship in a navigation process based on the navigation parameters; predicting tidal height changes of at least one tidal point on the target route in a future period of time based on the hydrographic information; dynamically determining actual water depth changes of the tidal point in the future period of time in combination with the tidal height changes and the hydrographic information; comparing and analyzing the actual water depth changes and the minimum safe water depth, and generating one or more passable time windows of the tidal point according to an analysis result; and outputting the passable time windows for use in ship navigation decision-making.

[0085] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when executed, can include the processes of the above-mentioned embodiment methods. Any reference to memory, storage, databases, or other media in this application and in examples provided herein, unless specifically stated otherwise, can include non-volatile and / or volatile memory. Non-volatile memory can include, for example, read only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include, for example, random access memory (RAM), or external cache memory. As an illustration and not a limitation, RAM is available in many forms such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), Synchlink DRAM (SLDRAM), Rambus DRAM (RDRAM), direct Rambus dynamic RAM (DRDRAM), and Rambus dynamic RAM (RDRAM), etc.

[0086] It should be noted that the terms "comprising", "including", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, device, article, or method that comprises a list of elements does not include only those elements recited, but can also include other elements not expressly listed or inherent to such process, device, article, or method. Without further limitation, an element defined by the phrase "comprising a" does not exclude the presence of additional identical elements in the process, device, article, or method that includes the element.

[0087] The above description is only the preferred embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation using the content of the specification and drawings, or direct or indirect application in other related technical fields, is also included in the patent protection scope of the present application.

Claims

1. A method of calculating a tidal window for a vessel's passage along a route, characterised in that, The method comprises: acquiring navigation parameters of a ship and hydrographic information of a target route; based on the navigation parameters, calculating the minimum safe water depth required by the ship during navigation; based on the hydrographic information, predicting the tidal height change of at least one tidal point on the target route within a future period of time; combining the tidal height change and the hydrographic information, dynamically determining the actual water depth change of the tidal point within the future period of time; comparing and analyzing the actual water depth change and the minimum safe water depth, and generating one or more passable time windows of the tidal point according to the analysis result; outputting the passable time windows for use in ship navigation decision.

2. The method of claim 1, wherein, The navigation parameters include static parameters and dynamic parameters of the ship; the static parameters at least include the full load draft of the ship, and the dynamic parameters at least include the ship speed; the hydrographic information at least includes the chart datum depth of the tidal point in the route; The step of calculating the minimum safe water depth required by the ship comprises: According to the ship speed and the chart datum depth, the sinking amount formula is used to calculate the sinking amount caused by the ship hull displacement effect and wave action during ship navigation; Based on the sinking amount, the total surplus water depth is calculated by combining the wave surplus water depth, the ship rolling surplus water depth and the safety reserve water depth; The full load draft of the ship, the sinking amount and the total surplus water depth are added to obtain the minimum safe water depth; The calculation formula of the sinking amount is: Wherein, k is a coefficient related to the type of the ship, A is the underwater cross-sectional area of the ship body, h is the current water depth, and v is the ship speed. The calculation formula of the total surplus water depth is: F = Δd + F1 + F2 + F3, wherein F1 is the wave surplus water depth, which is 1 / 2 of the estimated wave height; F2 is the ship rolling surplus water depth, which is 1 / 20 of the ship width; F3 is the safety reserve water depth determined according to the channel grade.

3. The method of claim 1, wherein, The step of predicting the tidal height change of at least one tidal point on the target route within a future period of time based on the hydrographic information comprises: acquiring the longitude and latitude coordinates of each tidal point on the target route; Based on the longitude and latitude coordinates of the tidal point, a tidal prediction model is called to calculate the tidal height of each time point within a future set period of time through the tidal prediction model; The tide prediction model is the harmonic constant method, and the tide height calculation formula is: wherein H0 is the average sea level height, H i is the amplitude of the i-th component tide, ω i is the angular frequency of the i-th component tide, is the initial phase of the i-th component tide, and t is time.

4. The method of claim 1, wherein, The step of comparing and analyzing the actual water depth change and the minimum safe water depth, and generating one or more passable time windows of the tidal point according to the analysis result comprises: When the number of tidal points contained in the target route is one, the actual water depth of the tidal point changing with time within a future period of time is calculated; Based on the calculation result, the actual water depth at each time is compared with the minimum safe water depth, and all time points satisfying the condition that the actual water depth is greater than or equal to the minimum safe water depth are screened out; According to the screening result, the time period to which the time points continuously satisfying the condition belong is merged to generate one or more continuous passable time windows of the tidal point.

5. The method of claim 4, wherein, The step of comparing and analyzing the actual water depth change and the minimum safe water depth, and generating one or more passable time windows of the tidal point according to the analysis result further comprises: When the target route contains multiple continuous tidal points, the ship speed is acquired; According to the sailing speed, a predicted sailing time of the ship between two adjacent tidal points is calculated; According to the calculation result, a passable time window of a tidal point and the predicted sailing time required to reach the next tidal point are determined; Based on the passable time window of the tidal point and the predicted sailing time required to reach the next tidal point, the associated passable time window of the next tidal point is calculated and determined.

6. The method of claim 1, wherein, After the step of outputting the passable time window for use in ship navigation decision, the method further comprises: A historical passing database associated with the target route is established, and the database records actual sailing data of other ships passing through each tidal point on the route, and the actual sailing data at least includes actual draft of the ship and passing time; Based on the historical passing database, a reverse depth verification is performed, and the step comprises: for a specific tidal point, ship data passing through the point at a known tidal height time is retrieved, and the actual depth of the point at this passing is calculated reversely according to the actual draft of the ship and the sailing parameters of the ship; A plurality of sets of actual depths calculated reversely are compared with the chart reference depth to generate a depth confidence evaluation result of the tidal point; In response to the depth confidence evaluation result being lower than a preset threshold, warning information about reliability of the chart reference depth of the tidal point is generated, and a modified safe depth value is suggested to be used for passing window calculation.

7. The method of claim 6, wherein, The step of performing the reverse depth verification based on the historical passing database further comprises: A credibility evaluation is performed on a single ship data record in the historical passing database, and the evaluation is based on type of the data source ship, positioning accuracy of the ship, and acquisition method of actual draft data of the ship in the record; According to the credibility evaluation result, a credibility weight is given to each data record; Wherein, when the actual depth of the point is calculated reversely, a weighted average algorithm based on the credibility weight is used for calculation; And when there is a significant conflict between a plurality of sets of actual depth values calculated reversely, a result of a high credibility weight data set is preferentially adopted, and an abnormal marking and review process of a low credibility data set is triggered.

8. A system for calculating tidal window passage for ship routes, characterized in that, Comprise: An acquisition module is configured to acquire sailing parameters of a ship and hydrographic information of a target route; A calculation module is configured to calculate a minimum safe depth required by the ship during sailing based on the sailing parameters; A prediction module is configured to predict tidal height changes of at least one tidal point on the target route in a future period of time based on the hydrographic information; A combination module is configured to combine the tidal height changes and the hydrographic information to dynamically determine actual depth changes of the tidal point in the future period of time; An analysis module is configured to compare and analyze the actual depth changes and the minimum safe depth, and generate one or more passable time windows of the tidal point according to the analysis result; An output module is configured to output the passable time window for use in ship navigation decision. 9.A computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the computer device is configured to perform the method according to any one of claims 1-8 when the computer program is executed by the processor. The processor executes the computer program to realize the steps of the method in any one of claims 1 to 7.

10. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program, which is executed by a processor, implements the steps of the method according to any one of claims 1 to 7.

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