A multi-sensor-based real-time monitoring method and system for ship hull posture

Abstract

The application discloses a kind of based on multi-sensor ship hull posture real-time monitoring method and system, suitable for the real-time monitoring of ship hull posture in the process of ship operation.The method is by setting in the left side, right side, bow and stern of ship draft sensor, real-time collection corresponding position draft data, and in combination with ship related structure parameters, the left and right side draft difference and the bow and stern draft difference are solved, the roll angle and the pitch angle of ship are obtained respectively, so as to realize the real-time monitoring of ship hull posture.The system includes draft data acquisition module, data processing module and posture output module.Compared with prior art, the application can directly reflect the roll and pitch state of ship hull based on the draft change of different positions of ship, with the advantages of simple structure, easy to implement, good monitoring real-time.

Description

Technical Field

[0001] This invention belongs to the field of marine propulsion technology, and in particular relates to a method and system for real-time monitoring of ship hull attitude based on multiple sensors. Background Technology

[0002] During ship loading and unloading, offshore construction, semi-submersible transport, heavy cargo deck operations, and berthing and unberthing in port, changes in the ship's attitude directly affect ship stability, the operational status of deck equipment, and operational safety. Especially when a ship is affected by changes in load distribution, ballast water adjustments, cargo shifting, wind and wave disturbances, or localized stress changes, the hull may experience heeling and trimming. If the ship's current attitude cannot be assessed in a timely manner, it can lead to delays in the assessment of the hull's condition by operators, thereby affecting the safety margins of lifting, loading, load adjustment, and berthing operations. Current ship attitude monitoring typically employs inclinometers, gyroscopes, inertial measurement units, satellite positioning systems, or relies on manual reading of draft gauges. While inclinometers and inertial devices can directly output attitude angles, their measurements are easily affected by hull vibration, equipment installation angle, instantaneous swaying, and sensor zero-point drift. During ship operations, this can lead to significant fluctuations in attitude angle readings, insufficient long-term stability, or the need for frequent calibration. Satellite positioning or inertial navigation systems are costly and require complex installation and maintenance. For engineering scenarios where only the overall heel and trim status of the hull needs to be monitored, the system complexity and operating costs are too high. Manual draft readings, while reflecting the draft at different positions, have long reading cycles, poor real-time performance, and are significantly affected by personnel experience, line-of-sight conditions, and water surface fluctuations, making them unsuitable for continuous monitoring at the operational site. Furthermore, one of the most direct external manifestations of a ship's heel or trim is the corresponding change in draft at different hull positions. For example, the difference in draft between the port and starboard sides reflects the lateral heel, while the difference between the bow and stern reflects the longitudinal heel. While some existing systems collect draft data for loading, ballast, or ship buoyancy management, they often only display draft as a single-point or local water level parameter. They fail to integrate draft changes on the port, starboard, bow, and stern with hull structural parameters to generate real-time calculations and outputs directly related to heel and trim angles. Therefore, current technologies for monitoring ship operational attitude still suffer from problems such as high equipment complexity, insufficient engineering adaptability, poor real-time performance of manual methods, and the inability of single-point draft data to fully reflect ship attitude. A simple, easy-to-install, real-time monitoring solution is needed that can directly reflect ship attitude using draft changes at different locations. Summary of the Invention

[0003] To address the technical problem that existing technologies cannot meet the high reliability requirements for attitude monitoring in shipborne lifting operations, this invention provides a method and system for real-time monitoring of ship hull attitude based on multiple sensors.

[0004] To achieve the above objectives, a method for real-time monitoring of ship hull attitude based on multiple sensors is provided in a first aspect of the present invention, comprising the following steps: S1. Install draft sensors on the port side, starboard side, bow, and stern of the ship respectively, determine the lateral horizontal distance between the draft sensors on the port and starboard sides and the longitudinal horizontal distance between the draft sensors on the bow and stern, and perform unified benchmark calibration on the four draft sensors to obtain the calibration offset of each sensor. S2. Collect the original draft measurement values ​​at four positions: port side, starboard side, bow, and stern, in real time according to a unified sampling period. Use the calibration offset to convert the original draft measurement values ​​into real-time draft values ​​after a unified reference. Combine the lateral horizontal spacing and longitudinal horizontal spacing with the real-time draft values ​​to form a real-time data set. S3. Read the port draft, starboard draft, bow draft and stern draft at the same sampling time from the real-time data set, calculate the difference between the starboard draft and the port draft to obtain the port draft difference, and calculate the difference between the bow draft and the stern draft to obtain the bow-stern draft difference. S4. Divide the difference in draft between the port and starboard sides by the horizontal distance between the two sides and take the arctangent to obtain the ship's heel angle; divide the difference in draft between the bow and stern by the horizontal distance between the two sides and take the arctangent to obtain the ship's trim angle; output the heel angle and trim angle as the real-time attitude result of the ship.

[0005] Furthermore, in S1, the method of unified reference calibration is as follows: when the ship is in a stable operating condition, the standard draft values ​​at the corresponding positions of the port side, starboard side, bow and stern are read, and the original measurement values ​​of the four draft sensors are read simultaneously. The calibration offset of each sensor is obtained by subtracting the original measurement value from the standard draft value.

[0006] Furthermore, in S1, the lateral horizontal distance between the port and starboard draft sensors is the horizontal projection distance between the actual installation points of the port and starboard sensors in the lateral direction of the hull; the longitudinal horizontal distance between the bow and stern draft sensors is the horizontal projection distance between the actual installation points of the bow and stern sensors in the longitudinal direction of the hull.

[0007] Furthermore, in S2, the real-time draft value after unifying the benchmark is obtained by adding the calibration offset of the corresponding sensor to the original draft measurement value; the real-time data set includes the port draft value, starboard draft value, bow draft value, stern draft value, transverse horizontal distance, and longitudinal horizontal distance at the same sampling time.

[0008] Furthermore, in S3, the difference in draft between the port and starboard sides is calculated by subtracting the draft from the starboard side, and the difference in draft between the bow and stern is calculated by subtracting the draft from the stern. When the draft on the port side is greater than the draft on the starboard side, the difference in draft between the port and starboard sides is negative, and the corresponding heel angle is negative. When the draft on the stern is greater than the draft on the bow, the difference in draft between the bow and stern is negative, and the corresponding trim angle is negative.

[0009] Furthermore, in S4, the calculation results of the yaw angle and pitch angle are output in radians or angles, and the output includes the sampling time, the yaw angle value, and the pitch angle value.

[0010] Furthermore, the draft sensor is a pressure-type draft sensor, an ultrasonic draft sensor, or a radar level-type draft sensor.

[0011] Furthermore, the draft sensor output signal is transmitted to the draft data acquisition module via a 4-20mA analog interface, RS485 interface, CAN interface, or Ethernet interface.

[0012] Furthermore, the unified sampling period is 1Hz, and the four draft sensors are triggered synchronously by the same clock to ensure the consistency of draft data on the port side, starboard side, bow, and stern in the time dimension.

[0013] Secondly, the present invention also provides a multi-sensor-based real-time ship hull attitude monitoring system for implementing any of the multi-sensor-based real-time ship hull attitude monitoring methods described in any one of the claims, comprising: The draft sensing module is used to install draft sensors on the port side, starboard side, bow, and stern of the ship, determine the lateral horizontal distance between the draft sensors on the port and starboard sides and the longitudinal horizontal distance between the draft sensors on the bow and stern, and perform unified benchmark calibration on the four draft sensors to obtain the calibration offset of each sensor. The draft analysis module is used to collect the original draft measurement values ​​at four positions: port, starboard, bow, and stern, in real time according to a unified sampling period. It uses the calibration offset to convert the original draft measurement values ​​into real-time draft values ​​after a unified reference, and combines the lateral horizontal spacing and longitudinal horizontal spacing with the real-time draft values ​​to form a real-time data set. The data processing module is used to read the port draft, starboard draft, bow draft and stern draft at the same sampling time from the real-time data set, calculate the difference between the starboard draft and the port draft to obtain the port draft difference, and calculate the difference between the bow draft and the stern draft to obtain the bow-stern draft difference. The attitude output module is used to divide the difference in draft between the port and starboard sides by the horizontal distance and take the arctangent to obtain the ship's heel angle; divide the difference in draft between the bow and stern by the horizontal distance in the longitudinal direction and take the arctangent to obtain the ship's trim angle; and output the heel angle and trim angle as the real-time attitude result of the hull.

[0014] The real-time monitoring method and system for ship hull attitude based on multiple sensors provided by this invention brings significant and multifaceted benefits compared to existing technologies.

[0015] The main inventive point of this invention is that it uses the draft data of four positions of the ship—port, starboard, bow, and stern—as the basic data source for ship attitude monitoring. By using multi-point draft sensors to collect the draft changes of different positions of the ship in real time, and combining them with relevant structural parameters of the ship, it calculates the difference in draft between the port and starboard sides and the difference in draft between the bow and stern, thereby obtaining the ship's heel angle and pitch angle respectively. This solution addresses the issues of existing inclinometers and inertial measurement equipment being susceptible to vibration, instantaneous swaying, and installation errors at ship operation sites. It uses the difference in draft at different hull positions as the basis for attitude judgment, allowing monitoring results to directly correspond to changes in the ship's buoyancy. To address the problems of poor real-time performance and insufficient continuity of manual draft readings, a draft data acquisition module enables real-time acquisition of draft data for the port, starboard, bow, and stern. Furthermore, to address the issue that single-point draft only reflects local draft and cannot represent the overall hull attitude, a data processing module maps the draft difference between the port and starboard sides to transverse structural parameters, and the draft difference between the bow and stern to longitudinal structural parameters, generating output results for heel and trim angles. Finally, addressing the high cost and demanding installation and maintenance requirements of traditional, highly complex attitude monitoring systems, this invention only requires a draft data acquisition module, a data processing module, and an attitude output module to achieve real-time hull attitude monitoring. Its clear structure and convenient implementation make it suitable for continuous monitoring of the hull's heel and trim states during ship operations. Attached Figure Description

[0016] The present invention will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention. For those skilled in the art, other drawings can be obtained based on the following drawings without creative effort.

[0017] Figure 1 This is a flowchart illustrating the working steps of a real-time ship attitude monitoring method based on multiple sensors, as disclosed in one embodiment of the present invention. Detailed Implementation

[0018] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0019] Example 1 refer to Figure 1 This invention provides an embodiment of a method for real-time monitoring of ship hull attitude based on multiple sensors, comprising the following steps: S1. Install draft sensors on the port side, starboard side, bow, and stern of the ship respectively, determine the lateral horizontal distance between the draft sensors on the port and starboard sides and the longitudinal horizontal distance between the draft sensors on the bow and stern, and perform unified benchmark calibration on the four draft sensors to obtain the calibration offset of each sensor. S2. Collect the original draft measurement values ​​at four positions: port side, starboard side, bow, and stern, in real time according to a unified sampling period. Use the calibration offset to convert the original draft measurement values ​​into real-time draft values ​​after a unified reference. Combine the lateral horizontal spacing and longitudinal horizontal spacing with the real-time draft values ​​to form a real-time data set. S3. Read the port draft, starboard draft, bow draft and stern draft at the same sampling time from the real-time data set, calculate the difference between the starboard draft and the port draft to obtain the port draft difference, and calculate the difference between the bow draft and the stern draft to obtain the bow-stern draft difference. S4. Divide the difference in draft between the port and starboard sides by the horizontal distance between the two sides and take the arctangent to obtain the ship's heel angle; divide the difference in draft between the bow and stern by the horizontal distance between the two sides and take the arctangent to obtain the ship's trim angle; output the heel angle and trim angle as the real-time attitude result of the ship.

[0020] As a preferred embodiment of the present invention, S1 specifically includes: Draft sensors are installed on the port side, starboard side, bow, and stern of the vessel. During the installation phase, the locations of the measuring points are confirmed, the draft measurement benchmark is standardized, and the hull structure parameters are entered. During on-site implementation, the approximate locations of the four measuring points are first determined based on the ship's general arrangement drawing and hull structure drawing. Then, the actual installation points are determined by considering the hull plating structure, sensor installation space, wiring conditions, and maintenance convenience. The port and starboard draft sensors are positioned near the same transverse section so that their draft data can be used to calculate the draft difference between the port and starboard sides. The bow and stern draft sensors are positioned longitudinally along the hull so that their draft data can be used to calculate the draft difference between the bow and stern. Draft sensors can be pressure-type, ultrasonic, or radar-based. When using pressure-type sensors, the pressure, current, or digital signals output by the sensor are transmitted to the draft data acquisition module via a 4–20mA analog interface, RS485 interface, CAN interface, or Ethernet interface. The draft data acquisition module then converts these signals into raw draft measurements in meters. The four measuring points use the same sampling period, for example, outputting data at a uniform sampling frequency of 1Hz and transmitting it to the data processing module in the same data format, so that the draft data of the four positions of port, starboard, bow and stern can be called and processed at the same sampling time.

[0021] Understandably, after the sensors are fixed, a unified reference calibration is performed on the four sensors. During calibration, the ship is positioned in calm water or other stable conditions while berthed. On-site personnel read the draft values ​​at corresponding positions on the port, starboard, bow, and stern, or use the standard draft value confirmed by ship loading calculations, and simultaneously read the original measurements from the four draft sensors at the same reference time. Because the sensor installation height, protective tube position, diaphragm center position, or level gauge zero point position may differ from the ship's draft reference, the original measurements need to be unified to the same draft reference through calibration offset. This calibration relationship originates from the zero-point correction relationship in metrology, where the calibrated measurement value is obtained by adding the zero-point offset to the original measurement value. In this scheme, this relationship is applied to the synchronous calibration of the four draft measuring points on the port, starboard, bow, and stern, enabling the four measuring points to generate directly comparable draft data. The specific relationship is as follows: ; in, Indicates the location of the draft measurement point, take , , , These correspond to the port side, starboard side, bow, and stern, respectively. The reference calibration time is generated by the system clock of the data acquisition module or data processing module. The data format is a timestamp, and the unit is 12000. ; For the first The raw draft measurement values ​​output by each draft sensor at the reference calibration time originate from the draft sensor at the corresponding location. These values ​​are transmitted to the draft data acquisition module via a 4–20mA, RS485, CAN, or Ethernet interface and converted to floating-point numbers. The unit is [unit missing]. ; For the first The calibration offset of each draft sensor is obtained by subtracting the original measurement value of the sensor at that location from the standard draft value at that location. The data format is floating-point, and the unit is [missing information]. ; For the first The draft values ​​of each measuring point after standardization at the benchmark calibration time are determined by the data processing module. and The calculated data is in floating-point format, and the unit is [missing information]. The left side of the formula The dimension of is length right side and The dimensions of all are length. The sum of the lengths is still the length. The dimensions on both sides of the formula are consistent. Taking the field debugging record as an example, at the reference calibration time... The standard draft values ​​for the port side, starboard side, bow, and stern are respectively , , and The raw converted values ​​synchronously read by the draft data acquisition module are as follows: , , and The calibration offsets at the four positions are respectively , , and After writing the above offset into the data processing module, the draft after port side calibration is... After starboard calibration, the draft is After bow calibration, the draft is After stern calibration, the draft is Thus, the sensor outputs at the four measuring points are unified to the same draft standard.

[0022] Furthermore, after standardizing the four draft measurement points, the hull structure parameters required for subsequent attitude calculations are calculated and entered. The lateral horizontal distance between the port and starboard draft sensors is defined as... This parameter is obtained from the horizontal projection distance between the actual installation points of the port and starboard sensors in the transverse direction of the hull; the longitudinal horizontal distance between the bow and stern draft sensors is defined as... This parameter is obtained from the horizontal projection distance between the actual installation points of the bow sensor and the stern sensor in the longitudinal direction of the hull. In practice, this distance can be obtained by verifying the horizontal distance between the sensor installation points using a total station, laser rangefinder, or steel ruler, or it can be calculated based on the coordinate differences of the sensor installation points in the hull drawings. If the coordinate method in the drawings is used, the difference between the port and starboard sensors in the lateral coordinates of the hull is... The difference between the sensors at the bow and stern on the longitudinal coordinates of the hull is... If on-site measurement is used, the measured actual horizontal projection distance is directly entered into the data processing module as the corresponding parameter. For example, if the width of a certain ship type is... However, due to structural limitations, the port and starboard sensors were installed at a position away from the inner side of the outer plating, and the horizontal projection distance between them measured on-site was [missing information]. ,but The overall length of a certain ship is However, the longitudinal horizontal projection distance between the actual installation points of the sensors at the bow and stern is... ,but Therefore, the output of this step is... and The distance is obtained by measuring or calculating the horizontal projected distance between the actual installation points of the sensors, and is saved to the data processing module in floating-point form, with units of 1. .in, Used to subsequently calculate the heel angle by combining the draft difference between the port and starboard sides. Used to calculate the pitch angle in subsequent calculations based on the difference in draft between the fore and stern.

[0023] As a preferred embodiment of the present invention, S2 specifically includes: In step one, the lateral horizontal distance between the draft sensors on the port and starboard sides has been obtained. and the longitudinal and horizontal spacing between the draft sensors at the bow and stern Subsequently, the draft data acquisition module synchronously collects data from four measuring points according to a unified sampling clock during ship operations, and directly organizes the collected data into a data format that can participate in subsequent geometric calculations. In on-site implementation, the port, starboard, bow, and stern draft sensors are connected to the acquisition module through independent signal channels. The 4–20mA current signal output by the pressure sensor is converted into a voltage signal by the internal resistance sampling circuit of the acquisition module, and then converted into a digital quantity by the A / D conversion chip. If it is a digital sensor with an RS485 or CAN interface, the value in the register is read through the serial port or bus interface. The acquisition module is internally set with a unified sampling period, for example... And all four channels are triggered by the same clock at the same sampling time. Data is read synchronously to ensure consistency of data on the port and starboard sides and at the bow and stern in the time dimension.

[0024] Understandably, after the acquisition module obtains the raw draft measurements from the four measuring points, the data processing module calls the calibration offset determined in step one. A unified reference transformation is performed on the data. This process is derived from the zero-point correction formula in surveying, which transforms measured values ​​to a unified reference standard by superimposing a fixed offset. In this scheme, this formula is used to unify the outputs of draft sensors at different installation locations to the same hull draft reference, ensuring physical consistency in subsequent draft difference calculations. Its expression is: ; in, These represent the port side, starboard side, bow, and stern, respectively. For the first The sampling time is generated by the clock of the acquisition module, and the unit is... ; For the first Each sensor at time The raw draft measurement value comes from the sensor output after A / D conversion or digital interface reading, and the unit is... ; The calibration offset, obtained in step one by comparing the standard draft value with the original measured value, is expressed in units of... ; The real-time draft value, after standardization, is calculated by the data processing module, and the unit is [unit missing]. The left and right sides of this formula are both length quantities, with dimensions of . It meets the requirement of dimensional consistency.

[0025] Furthermore, after obtaining the real-time draft values ​​at four measuring points, the data processing module further processes the structural parameters. and By binding the data with draft data, the collected data directly possesses the structural information required for geometric calculation. This processing is based on the fundamental idea of ​​"difference-scale correspondence" in analytical geometry, meaning that the height difference between two points in space must be combined with the horizontal distance between the two points to reflect the tilt state. Therefore, at each sampling time... Construct the following data combination relationship: ; in, Indicates at the sampling time The resulting real-time data set; , , and The real-time draft values ​​for the port side, starboard side, bow, and stern are respectively calculated using the zero-point correction formula mentioned above, and the units are... ; The lateral horizontal distance between the port and starboard sensors is derived from the measurement or calculation results in step one, and the unit is [unit missing]. ; The longitudinal horizontal distance between the sensors at the bow and stern is derived from the measurement or calculation results in step one, and the unit is [unit missing]. This combination essentially incorporates both "measured values" and "structural scales" into the same data structure, eliminating the need for additional parameter lookups in subsequent calculations and ensuring the continuity of the solution process. All elements in this formula are length quantities. The internal dimensions of the data structure are consistent.

[0026] Understandably, the calculations are explained in conjunction with on-site operational data: at a certain sampling time The data acquisition module reads the raw draft value. , , , In step one, the calibration offset is... , , , Then, according to the zero-point correction formula, the result is obtained. , , , Furthermore, the result obtained in step one... and Combined with the above draft data, we obtain This dataset contains the port and starboard drafts, fore and aft drafts, and corresponding structural parameters simultaneously, and can be directly used to calculate the port and starboard draft differences and fore and aft draft differences. Through the above processing, a dataset containing four real-time draft values ​​and two structural parameters is generated at each sampling time. This data set is generated collaboratively by the draft data acquisition module and the data processing module, and serves as the direct input for subsequent attitude calculations. This allows draft changes at different positions of the ship to participate in the calculations under the conditions of unified time, unified reference, and unified structural parameters, thus providing a complete and consistent data foundation for the calculation of heel and trim angles.

[0027] As a preferred embodiment of the present invention, S3 specifically includes: The real-time draft data set formed in step two Based on this, the data processing module reads the same sampling time according to a fixed field order. lower port draft Starboard draft Draft at the bow and stern draft and read the horizontal spacing. and vertical horizontal spacing Among them, the draft on the port side With starboard draft Used to create the difference in draft between port and starboard sides, and the draft at the bow. With the stern draft Used to create a difference in draft between the two ends; Used to identify the lateral structural parameters of the hull corresponding to the difference in draft between port and starboard sides. This is used to identify the longitudinal structural parameters of the hull corresponding to the difference in draft between the bow and stern. Through this data reading method, the real-time draft data output in step two and the hull structural parameters determined in step one are both incorporated into the data processing process of this step, which is consistent with the technical content in this patent abstract of "collecting draft data at the corresponding position in real time and calculating the difference in draft between the port and starboard sides and the difference in draft between the bow and stern in combination with the relevant structural parameters of the hull".

[0028] Furthermore, the calculation of the draft difference between port and starboard sides and the draft difference between the bow and stern originates from the relationship of height difference under the same reference datum in basic surveying and analytical geometry. That is, under the same reference datum, the vertical height difference between two measuring points can be obtained by subtracting the two measured values. This scheme applies this height difference relationship to four draft measuring points on the port, starboard, bow, and stern of the ship, and uses a fixed difference convention according to the direction of the ship's attitude monitoring: the draft difference between port and starboard sides is calculated by subtracting the draft from the port side, and the draft difference between the bow and stern is calculated by subtracting the draft from the stern. The resulting difference retains both the magnitude of the draft change and the directional information of the ship's attitude change. The specific calculation relationship is as follows: ; in, Sampling time The difference in draft between the port and starboard sides is determined by the data processing module based on the same real-time draft data set. Starboard draft and port draft Subtraction yields the result, in units of ; Sampling time The draft difference between the two ends is determined by the data processing module based on the same real-time draft data set. The bow draft of the ship and stern draft Subtraction yields the result, in units of ; , , and All data originates from the draft data collected in real-time by the draft sensors on the port side, starboard side, bow, and stern in step two, and converted using a unified reference. All units are... ; Derived from the lateral horizontal distance between the actual installation points of the draft sensors on the port and starboard sides, as determined in step one, the unit is... This step is used to determine Hull structure parameters corresponding to the port and starboard directions; Derived from the longitudinal horizontal distance between the actual installation points of the draft sensors at the bow and stern, as determined in step one, in units of... This step is used to determine The hull structure parameters corresponding to the bow and stern directions. (Left side of the above formula) and The dimensions of all are length. The dimensions of all draft values ​​on the right are also in length. The length remains the same after subtracting the lengths. The dimensions on both sides of the formula are consistent, which is consistent with the physical meaning of the difference in draft.

[0029] During on-site operation, the data processing module is based on real-time draft data sets. The difference is calculated by dividing the fields in the correct order. Taking a set of sampled data as an example, at a certain sampling time... The real-time draft data set is The fields represent the port draft in sequence. Starboard draft Draft at the bow stern draft Horizontal spacing and vertical horizontal spacing After reading the port and starboard drafts, the data processing module calculates the result by subtracting the port draft from the starboard draft. This result indicates that the draft on the port side is greater than that on the starboard side. This can be used as the difference in draft between port and starboard for subsequent calculations of the ship's heel angle; after the data processing module reads the bow and stern drafts, it calculates the difference by subtracting the stern draft from the bow. This result indicates that the bow draft is greater than the stern draft. This data can be used to subsequently calculate the ship's trim angle and the difference in draft between the bow and stern. Because of the data in this set... Corresponding to the difference in draft between port and starboard, Corresponding to the difference in draft between the two sterns, subsequent steps can directly […]. and Combined with the calculation of the tilt angle, and Combine this with the calculation of the pitch angle.

[0030] This step outputs the difference in draft between the port and starboard sides. and the difference in draft between the beginning and end .in, Starboard draft output from step two With port draft The calculated horizontal spacing is compared with the horizontal spacing output in step one. Maintain correspondence; The bow draft output from step two With the stern draft The calculated distance is compared with the vertical horizontal spacing output in step one. Maintain correspondence. Through this step, the draft data at different positions on the port side, starboard side, bow, and stern of the ship are converted into draft difference data that can reflect the changes in the ship's lateral and longitudinal attitudes, respectively, and serve as the direct calculation basis for subsequently obtaining the heel and trim angles.

[0031] As a preferred embodiment of the present invention, S4 specifically includes: The difference in draft between port and starboard sides is obtained in step three. and the difference in draft between the beginning and end Subsequently, the data processing module at the same sampling time The internal function calls the two differences mentioned above and then calls the corresponding hull structure parameters. and This converts the difference in draft from a length measurement into hull attitude angles. Specifically, The calculation is derived from the difference between the port and starboard draft data, and the corresponding hull structural parameter is the lateral horizontal distance between the port and starboard draft sensors. ; The difference between the draft data at the bow and the draft data at the stern is calculated, and the corresponding hull structural parameter is the longitudinal horizontal distance between the draft sensors at the bow and stern. The data processing module performs calculations according to the above correspondence, using the difference in draft between the port and starboard sides to obtain the ship's heel angle, and the difference in draft between the bow and stern to obtain the ship's trim angle. This is consistent with the technical content in the abstract of this patent, which states that "by combining relevant structural parameters of the hull, the difference in draft between the port and starboard sides and the difference in draft between the bow and stern are calculated to obtain the ship's heel angle and trim angle, respectively."

[0032] Furthermore, the calculation of heel and trim angles originates from the arctangent relationship of right triangles in analytic geometry and trigonometry. In a right triangle, given the vertical height difference and horizontal distance, the angle of inclination of the connecting line relative to the horizontal plane is equal to the arctangent of the ratio of the vertical height difference to the horizontal distance. This scheme applies this geometric relationship to the ship's draft measurement points: the draft difference between the two measurement points on the port and starboard sides is taken as the vertical side of the transverse right triangle, and the horizontal distance between the measurement points on the port and starboard sides is taken as the horizontal side of the transverse right triangle; the draft difference between the two measurement points on the bow and stern is taken as the vertical side of the longitudinal right triangle, and the horizontal distance between the measurement points on the bow and stern is taken as the horizontal side of the longitudinal right triangle. Therefore, the calculation relationship for the ship's heel and trim angles is obtained as follows: ; in, Sampling time The ship's heel angle is determined by the data processing module based on the port and starboard draft difference output in step three. Horizontal spacing The result is calculated in radians. It can also be converted into angles in the attitude output module. ; Sampling time The ship's trim angle is determined by the data processing module based on the bow-stern draft difference output in step three. Vertical and horizontal spacing The result is calculated in radians. It can also be converted into angles in the attitude output module. ; Derived from the starboard draft in step three With port draft The difference is calculated in units of . ; Derived from the bow draft in step three With the stern draft The difference is calculated in units of . ; The horizontal distance between the actual installation points of the port and starboard draft sensors, determined in step one and maintained in steps two and three, is expressed in units of [unit missing]. ; Derived from the longitudinal horizontal distance between the actual installation points of the bow and stern draft sensors, determined in step one and maintaining the corresponding relationship in steps two and three, the unit is [unit missing]. In terms of dimensions, The dimensions are , The dimensions are also The input to the arctangent function is a dimensionless quantity, and the output is an angle quantity. Therefore, the physical meaning of the left and right sides of the formula is consistent, which is in line with the geometric relationship of the ship attitude angle calculation.

[0033] The above formula has a direct logical relationship with the difference calculation in step three. Step three converts the draft data of the port side, starboard side, bow, and stern at the same sampling time into two vertical draft differences, i.e. and This step divides the two vertical draft differences by the corresponding horizontal spacing. and This process yields two dimensionless slope values; then, the slope values ​​are converted into angle values ​​using arctangent calculation. In this way, the draft data at different positions of the ship are sequentially processed through draft difference calculation and angle calculation, ultimately forming attitude results that directly represent the ship's heel and trim states.

[0034] Based on the on-site operational data, if at a certain sampling time Get the difference in draft between port and starboard sides Difference in draft between the front and rear ends And the corresponding horizontal spacing Longitudinal and horizontal spacing When the data processing module calculates the tilt angle, it first calculates... Then take the arctangent to get The attitude output module, after conversion to angles, is approximately When calculating the pitch angle, first calculate... Then take the arctangent to get After conversion to angles, it is approximately In this calculation, a negative heel angle indicates the transverse heel direction when the port draft is greater than the starboard draft, while a positive heel angle indicates the longitudinal heel direction when the bow draft is greater than the stern draft. This calculation process directly reflects the relationship between the port / port draft difference and the heel angle, and between the bow / stern draft difference and the heel angle.

[0035] Understandably, after obtaining the yaw angle... and pitch angle Subsequently, the attitude output module outputs both as the real-time attitude result of the hull according to a fixed output format. During engineering implementation, the data processing module can... , and This forms an attitude record, which is sent to the display terminal via Ethernet, serial port, CAN bus, or the ship monitoring system interface. Alternatively, the roll and pitch angles can be displayed in real-time on a local interface, and recorded in a time sequence. The output can retain radian values ​​for internal calculations while simultaneously displaying angle values ​​to the operator, for example, as "roll angle". pitch angle This step ultimately outputs the ship's heel angle. and pitch angle ,in Calculated from the difference in draft between port and starboard sides and the lateral horizontal spacing. The data is calculated from the difference in draft between the bow and stern and the longitudinal horizontal distance, thus enabling real-time monitoring of the ship's attitude.

[0036] This embodiment also provides a multi-sensor-based real-time ship attitude monitoring system for implementing any of the multi-sensor-based real-time ship attitude monitoring methods described in this embodiment, comprising: The draft sensing module is used to install draft sensors on the port side, starboard side, bow, and stern of the ship, determine the lateral horizontal distance between the draft sensors on the port and starboard sides and the longitudinal horizontal distance between the draft sensors on the bow and stern, and perform unified benchmark calibration on the four draft sensors to obtain the calibration offset of each sensor. The draft analysis module is used to collect the original draft measurement values ​​at four positions: port, starboard, bow, and stern, in real time according to a unified sampling period. It uses the calibration offset to convert the original draft measurement values ​​into real-time draft values ​​after a unified reference, and combines the lateral horizontal spacing and longitudinal horizontal spacing with the real-time draft values ​​to form a real-time data set. The data processing module is used to read the port draft, starboard draft, bow draft and stern draft at the same sampling time from the real-time data set, calculate the difference between the starboard draft and the port draft to obtain the port draft difference, and calculate the difference between the bow draft and the stern draft to obtain the bow-stern draft difference. The attitude output module is used to divide the difference in draft between the port and starboard sides by the horizontal distance and take the arctangent to obtain the ship's heel angle; divide the difference in draft between the bow and stern by the horizontal distance in the longitudinal direction and take the arctangent to obtain the ship's trim angle; and output the heel angle and trim angle as the real-time attitude result of the hull.

[0037] Finally, it should be noted that the real-time monitoring method and system for ship hull attitude based on multiple sensors disclosed in the embodiments of the present invention are merely preferred embodiments of the present invention and are only used to illustrate the technical solutions of the present invention, not to limit it. 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. Such 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 real-time monitoring of ship hull attitude based on multiple sensors, characterized in that, Includes the following steps: S1. Install draft sensors on the port side, starboard side, bow, and stern of the ship respectively, determine the lateral horizontal distance between the draft sensors on the port and starboard sides and the longitudinal horizontal distance between the draft sensors on the bow and stern, and perform unified benchmark calibration on the four draft sensors to obtain the calibration offset of each sensor. S2. Collect the original draft measurement values ​​at four positions: port side, starboard side, bow, and stern, in real time according to a unified sampling period. Use the calibration offset to convert the original draft measurement values ​​into real-time draft values ​​after a unified reference. Combine the lateral horizontal spacing and longitudinal horizontal spacing with the real-time draft values ​​to form a real-time data set. S3. Read the port draft, starboard draft, bow draft and stern draft at the same sampling time from the real-time data set, calculate the difference between the starboard draft and the port draft to obtain the port draft difference, and calculate the difference between the bow draft and the stern draft to obtain the bow-stern draft difference. S4. Divide the difference in draft between the port and starboard sides by the horizontal distance between the two sides and take the arctangent to obtain the ship's heel angle; divide the difference in draft between the bow and stern by the horizontal distance between the two sides and take the arctangent to obtain the ship's trim angle; output the heel angle and trim angle as the real-time attitude result of the ship.

2. The method for real-time monitoring of ship hull attitude based on multiple sensors as described in claim 1, characterized in that, In S1, the unified reference calibration method is as follows: when the ship is in a stable operating condition, the standard draft values ​​at the corresponding positions of the port side, starboard side, bow and stern are read, and the original measurement values ​​of the four draft sensors are read simultaneously. The calibration offset of each sensor is obtained by subtracting the original measurement value from the standard draft value.

3. The method for real-time monitoring of ship hull attitude based on multiple sensors as described in claim 1, characterized in that, In S1, the lateral horizontal distance between the port and starboard draft sensors is the horizontal projection distance between the actual installation points of the port and starboard sensors in the lateral direction of the hull; the longitudinal horizontal distance between the bow and stern draft sensors is the horizontal projection distance between the actual installation points of the bow and stern sensors in the longitudinal direction of the hull.

4. The method for real-time monitoring of ship hull attitude based on multiple sensors as described in claim 1, characterized in that, In S2, the real-time draft value after unifying the benchmark is obtained by adding the calibration offset of the corresponding sensor to the original draft measurement value; the real-time data set includes the port draft value, starboard draft value, bow draft value, stern draft value, transverse horizontal distance, and longitudinal horizontal distance at the same sampling time.

5. The method for real-time monitoring of ship hull attitude based on multiple sensors as described in claim 1, characterized in that, In S3, the difference in draft between the port and starboard sides is calculated by subtracting the draft from the starboard side, and the difference in draft between the bow and stern is calculated by subtracting the draft from the stern. When the draft on the port side is greater than the draft on the starboard side, the difference in draft between the port and starboard sides is negative, and the corresponding heel angle is negative. When the draft on the stern is greater than the draft on the bow, the difference in draft between the bow and stern is negative, and the corresponding trim angle is negative.

6. The method for real-time monitoring of ship hull attitude based on multiple sensors as described in claim 1, characterized in that, In step S4, the calculation results of the yaw angle and pitch angle are output in radians or angles, and the output includes the sampling time, the yaw angle value and the pitch angle value.

7. The method for real-time monitoring of ship hull attitude based on multiple sensors as described in claim 1, characterized in that, The draft sensor is a pressure-type draft sensor, an ultrasonic draft sensor, or a radar level-type draft sensor.

8. The method for real-time monitoring of ship hull attitude based on multiple sensors as described in claim 1, characterized in that, The draft sensor output signal is transmitted to the draft data acquisition module through a 4-20mA analog interface, RS485 interface, CAN interface or Ethernet interface.

9. The method for real-time monitoring of ship hull attitude based on multiple sensors as described in claim 1, characterized in that, The unified sampling period is 1Hz, and the four draft sensors are triggered synchronously by the same clock to ensure the consistency of draft data in the port, starboard, bow and stern dimensions over time.

10. A multi-sensor-based real-time ship hull attitude monitoring system for implementing the multi-sensor-based real-time ship hull attitude monitoring method as described in any one of claims 1 to 9, characterized in that, include: The draft sensing module is used to install draft sensors on the port side, starboard side, bow, and stern of the ship, determine the lateral horizontal distance between the draft sensors on the port and starboard sides and the longitudinal horizontal distance between the draft sensors on the bow and stern, and perform unified benchmark calibration on the four draft sensors to obtain the calibration offset of each sensor. The draft analysis module is used to collect the original draft measurement values ​​at four positions: port, starboard, bow, and stern, in real time according to a unified sampling period. It uses the calibration offset to convert the original draft measurement values ​​into real-time draft values ​​after a unified reference, and combines the lateral horizontal spacing and longitudinal horizontal spacing with the real-time draft values ​​to form a real-time data set. The data processing module is used to read the port draft, starboard draft, bow draft and stern draft at the same sampling time from the real-time data set, calculate the difference between the starboard draft and the port draft to obtain the port draft difference, and calculate the difference between the bow draft and the stern draft to obtain the bow-stern draft difference. The attitude output module is used to divide the difference in draft between the port and starboard sides by the horizontal distance and take the arctangent to obtain the ship's heel angle; divide the difference in draft between the bow and stern by the horizontal distance in the longitudinal direction and take the arctangent to obtain the ship's trim angle; and output the heel angle and trim angle as the real-time attitude result of the hull.

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