Ship oil tank oil quantity dynamic measurement method based on optical fiber compass attitude compensation

Abstract

The application provides a ship oil tank oil quantity dynamic measurement method based on an optical fiber compass attitude compensation, and comprises the following steps: installing an optical fiber compass on a ship to collect acceleration, angular velocity and inclination angle data of the ship in real time; simultaneously, installing a temperature sensor and a pressure sensor in an oil tank to collect temperature and pressure data of fuel oil in the oil tank; obtaining an oil quantity-stability parameter relationship model: in a ship design stage, a relationship model between ship oil tank oil quantity and ship stability parameters is established by combining theoretical calculation and experimental testing; when obtaining real-time oil quantity of the oil tank, the real-time ship stability parameters are substituted into the obtained oil quantity-stability parameter relationship model, and the real-time oil quantity of the ship oil tank is calculated; according to the collected real-time temperature and pressure data of the fuel oil in the oil tank, the calculated real-time oil quantity is compensated and corrected in temperature and pressure; and the application can accurately and timely measure the ship oil tank oil quantity.

Description

Technical Field

[0001] This invention relates to the field of marine fuel measurement technology, and in particular to a dynamic measurement method for marine fuel tank fuel quantity based on fiber optic compass attitude compensation. Background Technology

[0002] In marine propulsion systems, fuel oil is the primary energy source. Marine fuel oil (heavy oil) and ordinary diesel oil (light oil) are commonly used as fuels. To meet navigation needs, ships are typically equipped with multiple fuel tanks and containers for fuel storage. Accurately measuring and recording the fuel reserves in each tank is crucial, as it directly affects the ship's fuel replenishment plan and navigation safety.

[0003] Currently, the measurement of ship fuel reserves mainly relies on manual methods. For the main fuel tank, crew members typically use a gauging hammer to measure the fuel level through a gauging hole when the ship is berthed, and then convert this information into fuel reserves by referring to the ship's tank capacity table. If the ship is trimmed or listless, the measurement data must be corrected according to the angle of inclination. For day fuel tanks, the fuel level is read manually from the level gauge and the fuel capacity is calculated by referring to the tank capacity table. However, the above-mentioned traditional measurement methods have the following technical drawbacks:

[0004] 1. High dependence on manual labor and low efficiency: The measurement process relies entirely on crew operation, making real-time monitoring impossible, and it must be carried out while the ship is docked, resulting in delayed data updates;

[0005] 2. Measurement accuracy is affected by human factors: Since the cabin capacity table is based on ideal cabin dimensions, while there are individual differences in actual ship construction, coupled with the operating skills of the surveyors and the errors of the measuring tools, the accuracy of the final data is difficult to guarantee;

[0006] 3. Inability to meet the needs of refined management: Modern ship fuel management requires real-time and dynamic data support, while traditional manual measurement methods cannot provide continuous fuel consumption monitoring, affecting fuel optimization scheduling.

[0007] To overcome the aforementioned technical challenges, ship fuel inventory measurement systems based on fiber optic compasses and automated data calculations have emerged in recent years. These systems monitor real-time changes in fuel tank (cabinet) levels using automated sensing technology and dynamically correct these changes by combining them with ship attitude data, thus replacing traditional manual measurement methods. Compared to traditional methods, this technology improves measurement efficiency and reliability, reduces human error, and enables real-time dynamic monitoring of fuel inventory, providing data support for refined ship fuel management. However, existing automated measurement systems still face challenges such as sensor calibration and data fusion algorithm optimization, requiring further improvements to enhance measurement accuracy and system stability. Summary of the Invention

[0008] The purpose of this invention is to provide a high-precision dynamic measurement method for ship fuel tank quantity based on fiber optic compass attitude compensation, in order to solve the problems of existing ship fuel tank quantity measurement methods being greatly affected by ship attitude, having low measurement accuracy, and not fully considering fuel sloshing, and to achieve high-precision dynamic measurement of ship fuel tank quantity.

[0009] This application proposes a dynamic measurement method for ship fuel tank oil quantity based on fiber optic compass attitude compensation, including the following steps:

[0010] Fiber optic compasses are installed on the ship to collect real-time data on the ship's acceleration, angular velocity, and tilt angle; meanwhile, temperature and pressure sensors are installed in the fuel tanks to collect data on the temperature and pressure of the fuel.

[0011] Obtaining a model of the relationship between oil volume and stability parameters: During the ship design phase, a model of the relationship between the oil volume in the ship's oil tanks and the ship's stability parameters is established through a combination of theoretical calculations and experimental tests.

[0012] When obtaining the real-time oil volume in the oil tank, the real-time ship stability parameters are substituted into the obtained oil volume-stability parameter relationship model to calculate the real-time oil volume in the ship's oil tank.

[0013] Based on the real-time temperature and pressure data of the fuel in the fuel tank, the calculated real-time fuel quantity is corrected for temperature and pressure.

[0014] Furthermore, the method for establishing the relationship model between the oil volume in the ship's fuel tanks and the ship's stability parameters through a combination of theoretical calculations and experimental tests is as follows:

[0015] Under different fuel quantity conditions, the ship's stability parameters were measured, and the corresponding fuel quantity and stability parameter data were recorded. Using mathematical regression analysis, a functional relationship between fuel quantity and stability parameters was established.

[0016] Q = f(GM, X) G Y G Z G );

[0017] Among them, stability parameters include metacenter height and center of gravity position; Q represents the oil volume in the oil tank; GM is the metacenter height; X G Y G Z G These are the coordinates of the ship's center of gravity.

[0018] Furthermore, based on the collected real-time temperature and pressure data of the fuel in the fuel tank, the method for temperature and pressure compensation correction of the calculated real-time fuel quantity is as follows:

[0019] The temperature compensation correction formula is Q T=Q(1+βΔT), where β is the volumetric expansion coefficient of the fuel, ΔT is the change in fuel temperature, and Q represents the amount of fuel in the tank. T This indicates the oil level in the tank after temperature compensation.

[0020] The pressure compensation correction formula is Q P =Q T (1-αΔP), where α is the fuel compression coefficient, ΔP is the fuel pressure change, and Q P This indicates the amount of oil in the tank after pressure compensation.

[0021] Furthermore, the method also includes data processing and display, which involves filtering the calculated real-time oil volume data of the ship's oil tanks to remove noise interference, then displaying the oil volume data in real time through the ship's monitoring system, and storing the data in the ship's data center for subsequent querying and analysis.

[0022] Furthermore, the method also includes an early warning system that automatically issues an alarm signal when the oil level falls below a preset safety threshold, alerting staff to take action.

[0023] Furthermore, stability parameters include the height of the epicenter and the position of the center of gravity, and the specific calculation formulas are as follows:

[0024] The method for calculating the geocentric height GM is as follows:

[0025]

[0026] Where C0 is the dimensionless roll period coefficient of the ship, T is the roll period, and B is the ship's beam;

[0027] The method for calculating the position of the center of gravity is as follows:

[0028] The ship is divided into multiple parts, and the weight m of each part is calculated separately. i and the centroid coordinates (x i ,y i ,z i Then according to the formula Calculate the X of the ship's center of gravity G Y G Z G coordinate.

[0029] The advantages and positive effects of this invention are:

[0030] The method of this invention can accurately and in real time measure the oil level in a ship's fuel tank. The measurement accuracy meets the requirements of ship fuel management and navigation safety, and has good application prospects and promotion value. Attached Figure Description

[0031] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that these drawings are designed for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, unless specifically indicated, these drawings are intended only to conceptually illustrate the structural construction described herein and are not necessarily drawn to scale.

[0032] Figure 1 This is a flowchart illustrating the dynamic measurement method for ship fuel tank oil quantity based on fiber optic compass attitude compensation provided in an embodiment of the present invention. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this invention. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this invention, and should not be construed as limiting the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0034] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0035] like Figure 1 As shown, this embodiment provides a method for dynamic measurement of ship fuel tank quantity based on fiber optic compass attitude compensation, including the following steps:

[0036] Fiber optic compasses are installed on ships to collect real-time data on the ship's acceleration, angular velocity, and tilt. Simultaneously, temperature and pressure sensors are installed in the fuel tanks to collect data on the temperature and pressure of the fuel. It should be noted that, to ensure the accuracy of the collected data, the fiber optic compass should be installed on the ship's bow and stern baseline (centerline) plane, ensuring that its baseline coincides with or is parallel to the ship's bow and stern baselines, with an error controlled within ±0.5°. Typically, a dedicated bracket is used for fixed installation to ensure the compass body is level and stable, avoiding vibration interference.

[0037] Obtaining a model of the relationship between fuel quantity and stability parameters: During the ship design phase, a model is established to represent the relationship between fuel quantity in the ship's fuel tanks and the ship's stability parameters through a combination of theoretical calculations and experimental tests. Specifically, under different fuel quantity conditions, the ship's stability parameters are measured, and the corresponding fuel quantity and stability parameter data are recorded. Mathematical regression analysis is then used to establish the functional relationship between fuel quantity and stability parameters.

[0038] Q = f(GM, X) G Y G Z G );

[0039] Among them, stability parameters include metacenter height and center of gravity position; Q represents the oil volume in the oil tank; GM is the metacenter height; X G Y G Z G These are the coordinates of the ship's center of gravity.

[0040] It should be noted that the essence of measuring fuel quantity using ship stability is to infer load changes by inverting the angle of inclination. When the fuel quantity changes, the ship's total weight and center of gravity position will change, causing the ship to tilt (bow and stern) or list (board). By measuring this angle of inclination and combining it with the ship's stability parameters (such as metacenter height, moment of inertia, etc.), the change in fuel weight can be deduced.

[0041] The specific formulas for calculating the center of gravity height and center of gravity position are as follows:

[0042] The method for calculating the geocentric height GM is as follows:

[0043]

[0044] Where C0 is the dimensionless roll period coefficient of the ship, T is the roll period, and B is the ship's beam.

[0045] The method for calculating the position of the center of gravity is as follows:

[0046] The ship is divided into multiple parts, and the weight m of each part is calculated separately. i and the centroid coordinates (x i ,y i ,z i Then according to the formula (where n is the number of parts of the ship), calculate the X of the ship's center of gravity. G Y G Z G coordinate.

[0047] When the real-time oil volume in the oil tank is obtained, the real-time ship stability parameters are substituted into the obtained oil volume-stability parameter relationship model to calculate the real-time oil volume in the ship's oil tank.

[0048] Based on the collected real-time temperature and pressure data of the fuel in the fuel tank, the calculated real-time fuel quantity is corrected for temperature and pressure. Specifically, the method for correcting the calculated real-time fuel quantity for temperature and pressure is as follows:

[0049] The temperature compensation correction formula is Q T=Q(1+βΔT), where β is the volumetric expansion coefficient of the fuel, ΔT is the change in fuel temperature, and Q represents the amount of fuel in the tank. T This indicates the oil level in the tank after temperature compensation.

[0050] The pressure compensation correction formula is Q P =Q T (1-αΔP), where α is the fuel compression coefficient, ΔP is the fuel pressure change, and Q P This indicates the oil level in the tank after pressure compensation.

[0051] The temperature-compensated fuel tank volume is obtained using the supplementary formula described above, and the pressure-compensated fuel tank volume is used to obtain the final real-time fuel volume of the ship's fuel tanks. Temperature and pressure are key environmental factors affecting the measurement of fuel volume, density, and pressure. During ship navigation, temperature (such as diurnal temperature variation and sea ambient temperature) and pressure (such as tank pressure and changes in ship attitude) fluctuate frequently. Without compensation, this can lead to significant errors in fuel volume measurement results, affecting fuel consumption statistics, cost accounting, and loading safety. Therefore, temperature and pressure compensation is a necessary means to ensure the accuracy of fuel volume measurement in ship fuel tanks.

[0052] The above method also includes data processing and display. The calculated real-time oil level data of the ship's fuel tanks is filtered to remove noise interference. The oil level data is then displayed in real time through the ship's monitoring system and stored in the ship's data center for subsequent querying and analysis. Of course, the above method also includes early warning and reminders. When the oil level is lower than the preset safety threshold, an alarm signal is automatically issued to remind the staff to take action.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for dynamic measurement of ship fuel tank quantity based on fiber optic compass attitude compensation, characterized in that, Includes the following steps: Fiber optic compasses are installed on the ship to collect real-time data on the ship's acceleration, angular velocity, and tilt angle; at the same time, temperature and pressure sensors are installed in the fuel tanks to collect data on the temperature and pressure of the fuel. Obtaining a model of the relationship between oil volume and stability parameters: During the ship design phase, a model of the relationship between the oil volume in the ship's oil tanks and the ship's stability parameters is established through a combination of theoretical calculations and experimental tests. When obtaining the real-time oil volume in the oil tank, the real-time ship stability parameters are substituted into the obtained oil volume-stability parameter relationship model to calculate the real-time oil volume in the ship's oil tank. Based on the real-time temperature and pressure data of the fuel in the fuel tank collected, the calculated real-time fuel quantity is corrected for temperature and pressure. The method for establishing a model relating ship fuel tank volume to ship stability parameters through a combination of theoretical calculations and experimental testing is as follows: Under different fuel quantity conditions, the ship's stability parameters were measured, and the corresponding fuel quantity and stability parameter data were recorded. Using mathematical regression analysis, a functional relationship between fuel quantity and stability parameters was established. ; Among them, stability parameters include the height of the center of gravity and the position of the center of gravity; This indicates the fuel level in the fuel tank; GM is the geocentric height. , , These are the coordinates of the ship's center of gravity.

2. The method for dynamic measurement of ship fuel tank quantity based on fiber optic compass attitude compensation according to claim 1, characterized in that, The method for temperature and pressure compensation correction of the calculated real-time oil quantity based on the collected real-time temperature and pressure data of the fuel in the oil tank is as follows: The temperature compensation correction formula is as follows ,in, is the coefficient of volumetric expansion of fuel. This represents the change in fuel temperature. Indicates the amount of oil in the fuel tank; This indicates the oil level in the tank after temperature compensation. The pressure compensation correction formula is as follows ,in, The compression coefficient of fuel. This represents the change in fuel pressure. This indicates the amount of oil in the tank after pressure compensation.

3. The method for dynamic measurement of ship fuel tank quantity based on fiber optic compass attitude compensation according to claim 1, characterized in that, The method also includes data processing and display, which involves filtering the calculated real-time oil volume data of the ship's oil tanks to remove noise interference, then displaying the oil volume data in real time through the ship's monitoring system, and storing the data in the ship's data center for subsequent querying and analysis.

4. The method for dynamic measurement of ship fuel tank quantity based on fiber optic compass attitude compensation according to claim 1, characterized in that, The method also includes an early warning system that automatically issues an alarm signal when the oil level falls below a preset safety threshold, alerting staff to take action.

5. The method for dynamic measurement of ship fuel tank quantity based on fiber optic compass attitude compensation according to claim 1, characterized in that, Stability parameters include the height of the epicenter and the position of the center of gravity, and the specific calculation formulas are as follows: The method for calculating the geocentric height GM is as follows: ； in, T is the dimensionless roll period coefficient for the ship, where T is the roll period and B is the ship's beam. The method for calculating the position of the center of gravity is as follows: The ship is divided into multiple parts, and the weight of each part is calculated separately. and centroid coordinates ( , , Then according to the formula , , Calculating the center of gravity of a ship , , coordinate.

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