CN110366522B

CN110366522B - Ship load observation device, ship load observation method, and storage medium

Info

Publication number: CN110366522B
Application number: CN201880014702.1A
Authority: CN
Inventors: 中村拓; 户田裕行; 藤泽奈绪美
Original assignee: Furuno Electric Co Ltd
Current assignee: Furuno Electric Co Ltd
Priority date: 2017-03-03
Filing date: 2018-02-22
Publication date: 2022-02-11
Anticipated expiration: 2038-02-22
Also published as: EP3590818A4; CN110366522A; EP3590818A1; WO2018159440A1; EP3590818B1; JPWO2018159440A1; JP6880171B2

Abstract

The objective is to observe the hull load with a simple structure. The ship body load observation device (10) is provided with an acceleration measurement unit (21), an attitude measurement unit (22), an extraction unit (30), and a load calculation unit (40). An acceleration measuring unit (21) measures the acceleration of the hull. An attitude measurement unit (22) measures the attitude of the hull. An extraction unit (30) extracts the acceleration for load observation from the acceleration, and extracts the posture for load observation from the posture. A load calculation unit (40) calculates the load on the hull using the acceleration for load observation and the attitude for load observation.

Description

Ship load observation device, ship load observation method, and storage medium

Technical Field

The present invention relates to a hull load observation device, a hull load observation method, and a hull load observation program for observing a load applied to a hull due to waves and the like.

Background

In a ship such as a large commercial ship, a hull load applied by navigation becomes a problem. For example, slamming (slamming) and sloshing (striking) are factors that generate a hull load. Slamming is the impact of a wave when it collides with a hull and scouring is the vibration of the hull due to slamming.

The accumulation of the hull load may cause a change in the characteristics of the hull and damage to the hull, which affect safe navigation, driving, and the like.

Therefore, various systems for observing the load of the hull have been studied. For example, non-patent document 1 describes a ship load monitoring system using an optical fiber or the like and a high-precision sensor.

Prior art documents

Non-patent document

Non-patent document 1: network, http:// dspace. dsto.depth. gov. au/dspace/bitstream/desto/10246/1/DSTO-TR-2818% 20PR.pdf

Disclosure of Invention

Problems to be solved by the invention

However, the configuration described in non-patent document 1 requires a large-scale installation work, and the hull load cannot be observed with a simple configuration.

Accordingly, an object of the present invention is to provide a hull load observation device, a hull load observation method, and a hull load observation program capable of observing a hull load with a simple configuration.

Means for solving the problems

A ship body load observation device is provided with an acceleration measurement unit, an attitude measurement unit, an extraction unit, and a load calculation unit. An acceleration measuring unit measures the acceleration of the hull. The attitude measurement unit measures the attitude of the hull. The extraction unit extracts a load-observing acceleration generated by a phenomenon that is a factor causing a hull load from the acceleration, and extracts a load-observing attitude generated by the phenomenon from the attitude. The load calculation unit calculates a load using the acceleration for load observation and the posture for load observation.

In this configuration, the acceleration measuring unit and the posture measuring unit have uncomplicated structures, and the extracting unit and the load calculating unit connected thereto can be realized by an arithmetic processing device such as a normal CPU.

Effects of the invention

According to the present invention, the hull load can be observed with a simple configuration.

Drawings

Fig. 1 is a block diagram of a hull load observation device according to embodiment 1 of the present invention.

Fig. 2 is a block diagram showing an example of a configuration of a motion state measuring unit for realizing embodiment 1 of the present invention.

Fig. 3 (a) is a plan view of a ship equipped with the hull load observation device according to embodiment 1 of the present invention, and fig. 3 (B) is a side view of the ship equipped with the hull load observation device according to embodiment 1 of the present invention.

Fig. 4 is a flowchart of a main process executed by the hull load observing apparatus according to embodiment 1 of the present invention.

Fig. 5 is a flowchart of the 1 st load calculation process.

Fig. 6 is a flowchart of the 2 nd load calculation processing.

Fig. 7 is a flow chart of a flow of observation slamming.

Fig. 8 (a) is a schematic flowchart of the estimation of the surge, and fig. 8 (B) is a detailed flowchart of the estimation of the surge.

Figure 9 is a flow chart for calculating changes in attitude of a hull due to slamming using angular velocity.

Fig. 10 is a block diagram of a hull load observation device according to embodiment 2 of the present invention.

Fig. 11 (a) is a plan view of a ship equipped with the hull load observation device according to embodiment 2 of the present invention, and fig. 11 (B) is a side view of the ship equipped with the hull load observation device according to embodiment 2 of the present invention.

Fig. 12 is a flowchart for inferring the arrival direction of a wave that is the cause of a slam.

Fig. 13 is a flowchart of inferring surge transfer characteristics.

Fig. 14 is a block diagram of a navigation assistance system to which the hull load observation device according to the embodiment of the present invention is applied.

Detailed Description

A hull load observation device according to embodiment 1 of the present invention will be described with reference to the drawings. Fig. 1 is a block diagram of a hull load observation device according to embodiment 1 of the present invention. Fig. 2 is a block diagram showing an example of a configuration of a motion state measuring unit for realizing embodiment 1 of the present invention. Fig. 3 (a) is a plan view of a ship equipped with the hull load observation device according to embodiment 1 of the present invention, and fig. 3 (B) is a side view of the ship equipped with the hull load observation device according to embodiment 1 of the present invention.

As shown in fig. 1, the hull load observation device 10 includes a motion state measurement unit 20, an extraction unit 30, and a load calculation unit 40. The extraction unit 30 and the load calculation unit 40 constitute a data processing unit 50. The data processing unit 50 is realized by hardware such as a CPU that executes arithmetic processing, and a program that causes the arithmetic processing hardware to execute the processing of the extraction unit 30 and the processing of the load calculation unit 40.

The motion state measurement unit 20 is disposed at a position suitable for load calculation in the hull 100, and is disposed at the bow 101 of the hull 100 in the case of fig. 3 (a) and 3 (B), for example. Although not shown in fig. 3 (a) and 3 (B), the data processing unit 50 is provided in the steering room 110 of the hull 100. The exercise state measurement unit 20 and the data processing unit 50 are connected by a general-purpose communication means such as a communication cable, a wired LAN, or a wireless LAN. In other words, the exercise state measuring unit 20 and the data processing unit 50 are connected by a general-purpose and inexpensive communication means.

The exercise state measurement unit 20 includes an acceleration measurement unit 21 and an attitude measurement unit 22. The acceleration measuring unit 21 measures the acceleration of the hull 100 equipped with the hull load observing device 10. The attitude measurement unit 22 measures the attitude of the hull to which the hull load observation device 10 is attached. The acceleration measuring unit 21 outputs the acceleration to the extracting unit 30. The posture measuring unit 22 outputs the posture to the extracting unit 30. In the case of fig. 3 (a) and 3 (B), the acceleration measuring unit 21 measures the acceleration of the hull 100 at the bow 101. The attitude measurement unit 22 measures the attitude of the hull 100 at the bow 101.

The extraction unit 30 uses the acceleration and the attitude to observe a phenomenon such as slamming or surging, which is a factor causing a hull load (hereinafter simply referred to as a load).

The extraction unit 30 extracts the acceleration for load observation from the acceleration using the observation result. The load-observation acceleration is an acceleration generated by a phenomenon that causes a load, such as the above-described slamming or bumping. In other words, the load-observation acceleration is an acceleration obtained by removing an acceleration generated during normal navigation from the measured acceleration.

The extraction unit 30 extracts the posture for load observation from the postures using the observation results. The posture for load observation is a posture generated by a phenomenon that causes a load such as the above-described slamming or sloshing. In other words, the posture for load observation is a posture excluding a posture generated during normal navigation from the measured postures.

The extraction unit 30 outputs the load-observing acceleration and the load-observing posture to the load calculation unit 40.

The load calculation unit 40 calculates the load on the hull 100 using the load observation acceleration and the load observation attitude. Specifically, the load calculation unit 40 calculates a load index value from the load observation acceleration and the load observation attitude. For example, the load index value is calculated as a value corresponding to the posture for load observation and the acceleration for load observation. The load index value is calculated such that the value of the load index value increases as the acceleration for load observation increases.

In this case, the load index value may be calculated such that the larger the amount or rate of change of the load observation acceleration, the larger the value of the load index value. In this case, the amount of change or the change speed of the load-observing acceleration is calculated from the load-observing acceleration before and after the time when a phenomenon that is a factor causing the load occurs.

In this case, the load index value may be calculated such that the larger the amount or rate of change of the load observation posture, the larger the value of the load index value. In this case, the amount of change or the change speed of the posture for load observation is calculated from the posture for load observation before and after the time when a phenomenon that causes the load is generated.

The load calculation unit 40 integrates the sequentially calculated load index values. The load calculation unit 40 calculates the integrated value as a load. In this case, the load calculation unit 40 may set a threshold value for the index value to the load index value and accumulate the load index value only when the load index value exceeds the threshold value for the index value.

For example, the load calculation unit 40 compares the load, which is the integrated value of the load index values, with a predetermined notification threshold. The load calculation unit 40 notifies a warning or the like when the load exceeds a notification threshold.

By using such a configuration, the load on the hull 100 due to slamming or sloshing can be calculated with a simple configuration. Further, the load of the hull 100 can be notified of the dangerous level by an easily realized configuration.

The hull load observation device 10 calculates the load from only the acceleration and the attitude that are factors causing the load by using the acceleration for load observation extracted from the acceleration and the attitude for load observation extracted from the attitude. Therefore, the hull load observation device 10 can calculate the load with high accuracy.

In the above description, the respective processes are executed for each functional unit, but the processes of the functional units may be stored as a program and the program may be executed by hardware such as a CPU for performing arithmetic processing. In this case, the processing is executed based on the flow shown below. Fig. 4 is a flowchart showing a main process of load observation according to embodiment 1 of the present invention.

As shown in fig. 4, the hardware for arithmetic processing (hereinafter referred to as an arithmetic processing unit) acquires the acceleration and attitude of the hull (S101). The arithmetic processing device extracts the acceleration for load observation from the acceleration, and extracts the posture for load observation from the posture (S102). The arithmetic processing unit calculates a load using the acceleration for load observation and the posture for load observation (S103).

The specific load calculation method is, for example, the method shown in fig. 5 and 6. Fig. 5 is a flowchart of the 1 st load calculation process. Fig. 6 is a flowchart of the 2 nd load calculation processing.

In the case shown in fig. 5, the arithmetic processing unit calculates the load index value as described above based on the load observation acceleration and the load observation posture (S111). The arithmetic processing device integrates the load index value to calculate the load (S112).

In the case shown in fig. 6, the arithmetic processing unit calculates the load index value from the load observation acceleration and the load observation posture as described above (S111). When the load index value exceeds the index value threshold (YES in S113), the arithmetic processing unit calculates the load by accumulating the load index value (S112). If the load index value does not exceed the index value threshold (NO in S113), the arithmetic processing unit calculates the load without adding the load index value to the cumulative value (S114). In the case of using the method shown in fig. 6, if the load index value is small to such an extent that it does not adversely affect (e.g., fatigue) the hull 100, the load index values in this case are not integrated. This makes it possible to calculate the load with high accuracy.

Next, an example of a specific configuration of the exercise state measuring unit 20 will be described with reference to fig. 2.

The exercise state measurement unit 20 includes

antennas

201, 202, and 203, receiving

units

204, 205, and 206, an inertial sensor 207, and a calculation unit 208. The antenna 201 is connected to the receiver 204, the antenna 202 is connected to the receiver 205, and the antenna 203 is connected to the receiver 206. The receiving

units

204, 205, and 206 and the inertial sensor 207 are connected to the arithmetic unit 208.

The

antennas

201, 202, and 203 are not all arranged in a single line. The antenna 201 receives the positioning signal and outputs the positioning signal to the receiving unit 204. The antenna 202 receives the positioning signal and outputs the positioning signal to the receiving unit 205. Antenna 203 receives the positioning signal and outputs the signal to receiving unit 206. The positioning signal is a signal transmitted from a positioning satellite such as a GNSS satellite, and is a signal obtained by modulating a carrier signal for each code specific to the positioning satellite. The carrier signal is superimposed with a navigation message including orbit information of the positioning satellite and the like. The

antennas

201, 202, and 203 may receive at least four positioning signals common to them.

The receiver 204 captures and tracks the positioning signal received by the antenna 201, and observes a code phase and a carrier phase. The receiver 205 captures and tracks the positioning signal received by the antenna 202, and observes a code phase and a carrier phase. The receiver 206 captures and tracks the positioning signal received by the antenna 203, and observes a code phase and a carrier phase.

The receiving

units

204, 205, and 206 observe the code phase and the carrier phase at predetermined time intervals. The receiving

units

204, 205, and 206 output the observed carrier phase to the arithmetic unit 208 together with the observation time. The receiving

units

204, 205, and 206 may output the code phase to the arithmetic unit 208, or may output the code pseudo range obtained from the code phase or the positioning result based on the code pseudo range to the arithmetic unit 208.

The inertial sensor 207 includes at least an acceleration sensor. The inertial sensor 207 measures the acceleration of the three orthogonal axes of the hull coordinate system at the installation position, and outputs the measured acceleration to the calculation unit 208.

The calculation unit 208 calculates the angular velocity and the attitude of the hull 100 at the installation position of the motion state measurement unit 20 using the carrier phase. More specifically, the arithmetic unit 208 sets the baseline vectors for the

antennas

201, 202, and 203 using the differences in carrier phase (carrier phase differences) among the receiving

units

204, 205, and 206. The calculation unit 208 calculates angular velocities around the three orthogonal axes of the absolute coordinate system from the change in the baseline vector obtained at each observation time. The calculation unit 208 calculates the attitude of the hull 100 by converting the angular velocities around the three orthogonal axes of the absolute coordinate system into a hull coordinate system.

The calculation unit 208 directly uses the output of the inertial sensor 207 as the acceleration output of the hull 100. The calculation unit 208 may calculate the acceleration of the hull 100 by correcting the output of the inertial sensor 207 using the acceleration calculated from the carrier phase. This can improve the accuracy of acceleration calculation.

In this way, in the configuration shown in fig. 2, the acceleration measuring unit 21 of fig. 1 is realized by the inertial sensor 207 and the arithmetic unit 208. In the configuration shown in fig. 2, the posture measuring unit 22 shown in fig. 1 is realized by the receiving

units

204, 205, and 206 and the arithmetic unit 208. Thus, with a simple configuration such as a device integrating the positioning calculation function and the inertial sensor, the acceleration of the extraction source serving as the acceleration for load observation and the posture of the extraction source serving as the posture for load observation can be measured.

In addition, the inertial sensor 207 can be omitted in the motion state measurement unit 20, and in this case, the acceleration may be calculated using the carrier phase. On the other hand, in the motion state measurement unit 20, the

antennas

201, 202, and 203 and the receiving

units

204, 205, and 206 may be omitted, and the inertial sensor 207 may be provided with an acceleration sensor and an attitude sensor. The inertial sensor 207 may be provided with an angular velocity sensor, and the attitude of the extraction source serving as the load observation attitude may be calculated using the output of the angular velocity sensor and the angular velocity based on the carrier phase.

Next, an observation method for extracting the slamming and sloshing of the acceleration and posture for load observation will be described. As shown in fig. 3 (B), slamming is an impact generated when a wave collides with the hull 100. As shown in fig. 3 (B), the surge is a vibration generated in the hull 100 due to slamming.

In general, the extracting unit 30 observes the slamming using the accelerations at a plurality of observation times. The extraction unit 30 observes the surge using the acceleration or the change in posture (angular velocity) at a plurality of observation times. The extraction unit 30 detects the occurrence timing of the slamming or ringing. That is, the extraction unit 30 also functions as a detection unit that detects the occurrence timing of a phenomenon that becomes a factor causing the hull load.

Fig. 7 is a flow chart of a flow of observation slamming.

First, the extraction unit 30 buffers the accelerations at a plurality of observation times (S211). At this time, the extraction unit 30 also buffers the attitude together with the acceleration. The extraction unit 30 acquires the Z-axis acceleration az included in the acceleration at each observation time (S212). The Z-axis acceleration az is an acceleration in the vertical (vertical) direction in the hull coordinate system.

The extraction unit 30 performs high-pass filtering (HPF) processing on the Z-axis acceleration az (S213). The slamming Z-axis acceleration az is higher in frequency than the steady-state Z-axis acceleration due to a normal wave. Therefore, the threshold frequency of the high-pass filtering process is set between the steady-state Z-axis acceleration due to the normal waves and the Z-axis acceleration az that is experimentally, empirically, or due to a simulation of a pre-acquired slamming. By performing this processing, the steady-state components due to the normal waves included in the Z-axis acceleration are removed.

The extraction unit 30 compares the HPF post-acceleration azf with the threshold Th (S214). The threshold Th is set to a lower limit value of the Z-axis acceleration at which it can be determined that a wave collides with the hull 100 and slams. The threshold Th is a value determined experimentally, empirically, or by simulation, and may be changed based on the motion state of the hull. For example, the threshold Th may be increased in a storm weather and decreased in a stationary weather.

If the HPF post-acceleration azf is equal to or greater than the threshold Th (azf ≧ Th) (S215: yes), the extraction unit 30 detects the occurrence of a crash (S216). When the generation of the slap is detected, the extraction unit 30 stores the accelerations at a plurality of observation times before the generation of the slap is detected (S217). At this time, the extraction unit 30 stores the acceleration and the posture. In addition, when only the slamming detection is performed, step S217 can be omitted.

The extraction unit 30 sets the HPF post-acceleration azf at the slamming-on time as the load observation acceleration. The extraction unit 30 sets the posture of the slamming time as the posture for load observation.

On the other hand, if the HPF rear acceleration azf is smaller than the threshold Th (azf < Th) (S215: no), the data processing unit 50 determines that no slamming has occurred.

By using such a configuration and processing, the extraction unit 30 can observe the slamming. In this case, if the acceleration using the carrier phase is used, the extraction unit 30 can accurately observe the slamming, and can extract the high-accuracy acceleration for load observation.

Further, the extraction unit 30 can accurately separate the acceleration due to the swing of the normal hull 100 and the acceleration due to the impact of the slamming by using the HPF post-acceleration azf. This enables the extraction unit 30 to observe the slamming with higher accuracy.

Fig. 8 (a) is a schematic flowchart of the estimation of the surge. Fig. 8 (B) is a detailed flowchart of the estimation of the surge.

As shown in fig. 8 a, the extraction unit 30 acquires the postures of the plurality of observation times before and after the occurrence of the slamming (S301). The extraction unit 30 calculates the change speed of the posture from the postures at the plurality of observation times. The extraction unit 30 performs frequency analysis of the change speed of the posture (S302). The frequency resolution refers to a process (for example, FFT process) of calculating a spectrum of a change speed of the attitude. The extraction unit 30 estimates the frequency of the sloshing and the intensity of the sloshing from the frequency spectrum (S303).

More specifically, as shown in fig. 8B, the extraction unit 30 detects a peak of the spectrum of the change speed of the posture, and detects the peak intensity PS (S311). The extraction unit 30 compares the peak intensity PS with the surge detection threshold Thp. The surge detection threshold Thp is set to a lower limit value at which the spectral intensity at which the occurrence of the surge can be determined. The surge detection threshold value Thp is a value determined experimentally, empirically, or by simulation, and may be changed based on the motion state of the hull. For example, the surge detection threshold value Thp may be increased in stormy weather and may be decreased in stationary weather.

When the peak intensity PS is equal to or higher than the surge detection threshold Thp (PS ≧ Thp) (S312: yes), the extraction unit 30 determines that a surge has occurred (S313). Then, the extraction unit 30 sets the peak intensity PS to the intensity of the surge. The extraction unit 30 sets the frequency of the peak intensity PS as the frequency of the impulsive motion. On the other hand, if the peak intensity PS is smaller than the surge detection threshold Thp (PS < Thp) (S312: no), the extraction unit 30 determines that no surge is generated.

The extraction unit 30 sets the posture at the time of occurrence of the surge as the posture for load observation. The extraction unit 30 sets the post-HPF acceleration azf at the surge generation time as the load observation acceleration.

Here, as described above, the attitude is calculated with high accuracy using the carrier phase. Therefore, with such a configuration and processing, the extraction unit 30 can reliably and accurately determine the occurrence of the sloshing with a simple configuration. Furthermore, the extracting unit 30 can reliably and accurately detect the intensity of the sloshing and the frequency of the sloshing with a simple configuration. This makes it possible to accurately calculate the load index value and the load.

The posture, the amount of change in the posture, and the change speed of the posture at the time of occurrence of the phenomenon that causes the load can be calculated from the angular velocity using the angular velocity sensor. Figure 9 is a flow chart for calculating changes in attitude of a hull due to slamming using angular velocity.

The extraction unit 30 detects the occurrence of the slamming as described above, and acquires angular velocities at a plurality of observation times before and after the occurrence of the slamming (S401). The extraction unit 30 performs low-pass filtering processing on the angular velocity (S402). Various kinds of noise are contained in the angular velocity, and in general, the frequency of the noise is higher than that of the angular velocity caused by the slamming. Therefore, the noise is removed by low-pass filtering the angular velocity.

The extraction unit 30 calculates the posture within a predetermined time before and after the occurrence of the slamming by using the angular velocity (S403). The predetermined time may be set as appropriate, or may be different between the case before the occurrence of the slamming and the case after the occurrence of the slamming.

The extraction unit 30 calculates the posture change amount using the difference between the posture before the slap generation and the posture after the slap generation (S404). Alternatively, the extraction unit 30 calculates the posture change speed using the time change amount of the posture before the slap generation and the posture after the slap generation (S404).

In the above processing, a load using the amount of change in acceleration or posture is calculated. However, by using the direction of change in the acceleration and the direction of change in the attitude, the direction of displacement of a specific position of the hull 100, which may be a factor of the load, can be extracted. For example, the direction of displacement in the Z-axis direction of a specific position of the hull 100 such as the bow 101 can be extracted. This makes it possible to detect whether a specific position such as the bow 101 is lowered or raised due to slamming, that is, to detect the state of impact of the sea water.

In the above configuration, the exercise state measuring unit 20 is provided with the 3

antennas

201, 202, and 203 and the receiving

units

204, 205, and 206. However, by providing an acceleration sensor as the inertial sensor, the motion state measurement unit 20 may include at least 2 antennas and 2 receiving units.

Next, a hull load observation device according to embodiment 2 of the present invention will be described with reference to the drawings. Fig. 10 is a block diagram of a hull load observation device according to embodiment 2 of the present invention. Fig. 11 (a) is a plan view of a ship equipped with the hull load observation device according to embodiment 2 of the present invention. Fig. 11 (B) is a side view of a ship equipped with the hull load observation device according to embodiment 2 of the present invention.

As shown in fig. 10, 11 (a), and 11 (B), a hull load observation device 10A according to the present embodiment is different from the hull load observation device 10 according to embodiment 1 in that it includes a motion

state measurement unit

20A, 20B, 20C, and 20D, and the motion state measurement unit is connected to a data processing unit 50A.

The motion

state measurement units

20A, 20B, 20C, and 20D are disposed at different positions in the hull 100. In other words, a plurality of sets of the acceleration measuring unit 21 and the attitude measuring unit 22 are provided, and the acceleration measuring unit 21 and the attitude measuring unit 22 are placed at different positions in the hull 100 for each set.

The exercise

state measuring units

20A, 20B, 20C, and 20D have the same configuration. As shown in fig. 11 (a) and 11 (B), the motion

state measuring units

20A, 20B, 20C, and 20D are provided on the hull 100. The motion state measurement unit 20A is provided at the bow 101 of the hull 100. The moving state measuring unit 20B is provided at an intermediate position of the hull 100 in the bow-stern direction (X-axis direction of the hull coordinate system). The motion

state measuring units

20C and 20D are provided above a steering room 110 near the stern 102 of the hull 100. The motion

state measuring units

20C and 20D are provided near the starboard or the port of the hull 100, respectively. The motion

state measurement units

20C and 20D are arranged such that a base line connecting the motion

state measurement units

20C and 20D is parallel to the starboard-port direction (Y-axis direction of the hull coordinate system).

The data processing unit 50A performs load observation similar to the load observation (detection of a slamming, detection of occurrence of a sloshing, or the like) described in embodiment 1 above with respect to the installation positions of the motion

state measuring units

20A, 20B, 20C, and 20D. Thereby, the hull load observing apparatus 10 can individually observe the load at each of the plurality of positions of the hull 100. Further, the loads at the plurality of positions can be synchronized with high accuracy at the time of the positioning system that can demodulate the positioning signal. This makes it possible to observe the load occurring at the same time at a plurality of positions of the hull 100.

The arrangement of the exercise

state measurement units

20A, 20B, 20C, and 20D is not limited to this, and it is preferable that not all of the exercise

state measurement units

20A, 20B, 20C, and 20D be arranged in a straight line. Thus, even if there is one antenna provided in the motion

state measurement units

20A, 20B, 20C, and 20D, a plurality of baseline vectors can be set, and the baseline vectors can be used for load observation. In other words, if there is one antenna in the motion

state measurement units

20A, 20B, 20C, and 20D, a plurality of baseline vectors can be set and used for observing a load using a carrier phase.

As a specific example, in the configuration shown in fig. 11 (a), the exercise state measurement unit 20B is disposed at a position on any of the baseline that is not located on the baseline connecting the exercise state measurement unit 20A and the exercise state measurement unit 20C, the baseline connecting the exercise state measurement unit 20A and the exercise state measurement unit 20D, and the baseline connecting the exercise state measurement unit 20C and the exercise state measurement unit 20D. This makes it possible to increase the number of baseline vectors that are not parallel to each other as much as possible within the limit of the number of motion state measurement units. The exercise

state measurement units

20A, 20B, 20C, and 20D are preferably arranged so as to extend over a wide range, that is, so that the length of the baseline vector connecting the exercise state measurement units is long. This improves the calculation accuracy of the baseline vector, and improves the calculation accuracy of the attitude and thus the calculation accuracy of the load.

Further, the time of the positioning system can be used for synchronization, and the data processing unit 50A can observe the factors causing the load as described below. As the observed factors causing the load, for example, the arrival direction of the collision of the waves, the transfer characteristics of the surge, and the like are estimated.

The data processing unit 50A acquires the accelerations at the plurality of observation times after the slamming output from the motion

state measuring units

20A, 20B, 20C, and 20D14 is generated (S501).

The data processing unit 50A extracts the acceleration for load observation for each acceleration. The data processing unit 50A synchronizes the accelerations (acceleration for load observation) of the exercise

state measuring units

20A, 20B, 20C, and 20D. Synchronization of the acceleration (acceleration for load observation) is performed using an observation time acquired together with the acceleration (acceleration for load observation). Since the observation time uses the time of the positioning system, the observation times can be synchronized with high accuracy.

The data processing unit 50A detects the maximum acceleration of the accelerations (load observation accelerations) of the exercise

state measuring units

20A, 20B, 20C, and 20D at the same time (S502).

The data processing unit 50A estimates the position of the motion state measuring unit that has observed the maximum acceleration with respect to the hull 100 as the arrival direction of the wave that is the cause of the slamming (S503).

As described above, since the acceleration at each observation time is calculated with high accuracy and the accelerations of the respective exercise state measurement units are synchronized with the high-accuracy observation time, the maximum acceleration calculated from the acceleration of the respective exercise state measurement units is also detected with high accuracy. Therefore, by using this configuration and processing, the hull load observation device 10A can reliably and accurately detect the arrival direction of the wave that causes slamming with a simple configuration, and can accurately observe the load.

Further, since the acceleration can be synchronized based on the highly accurate observation time, the arrival direction of the wave which is the cause of the slamming can be detected with a low-cost configuration without requiring a large-scale process.

Fig. 13 is a flowchart of inferring surge transfer characteristics.

The data processing unit 50A detects the surge for each of the exercise

state measuring units

20A, 20B, 20C, and 20D by using the above-described method (S601). At this time, the data processing unit 50A also detects the surge detection data including the intensity (amplitude) and frequency of the surge. The data processing unit 50A sets the detection time of the intensity (amplitude) and frequency of the surge based on the observation time, and includes the detection time in the surge detection data.

The data processing unit 50A synchronizes the surge detection data of the motion

state measuring units

20A, 20B, 20C, and 20D to estimate the surge transfer characteristic. That is, the data processing unit 50A estimates the surge transfer characteristic using the amplitude characteristic or the frequency characteristic of the acceleration of the motion

state measuring units

20A, 20B, 20C, and 20D or the amplitude characteristic or the frequency characteristic of the change amount (change speed) of the posture. Specifically, the data processing unit 50A estimates the transmission direction of the surge by using the time series, which is the difference between the detection times of the motion

state measuring units

20A, 20B, 20C, and 20D corresponding to the frequency component detected as the surge. The data processing unit 50A estimates the attenuation characteristics of the surge due to the transmission, etc. from the intensities of the surges detected by the motion

state measuring units

20A, 20B, 20C, and 20D, respectively. Thus, the data processing unit 50A can estimate the intensity of the sloshing at a desired position of the hull 100. Therefore, the hull load observation device 10A can estimate and observe the load at an arbitrary position of the hull 100 using the surge transfer characteristic.

Further, since the acceleration can be synchronized based on the highly accurate observation time, the surge transfer characteristic can be estimated with a low-cost configuration without requiring a large-scale process.

The hull

load observation devices

10 and 10A described above can be used in a navigation assistance system as described below. Fig. 14 is a block diagram of a navigation assistance system to which the hull load observation device according to the embodiment of the present invention is applied.

As shown in fig. 14, the navigation support system 80 includes a hull load observation device 10A, a support unit 70, a ship speed acquisition unit 61, a steering angle acquisition unit 62, and a sea state acquisition unit 63. The hull load observation device 10A, the ship speed acquisition unit 61, the rudder angle acquisition unit 62, and the sea state acquisition unit 63 are connected to the auxiliary unit 70.

The ship speed obtaining unit 61 obtains the ship speed by calculating the speed from the acceleration of any one of the motion

state measuring units

20A, 20B, 20C, and 20D. Alternatively, the ship speed acquisition unit 61 is connected to a doppler sonar attached to the hull 100, and acquires the ship speed by a known method based on an output value of the doppler sonar.

The rudder angle obtaining unit 62 is connected to a rudder angle sensor attached to the hull 100, and obtains a rudder angle by a known method based on an output value of the rudder angle sensor.

The sea state acquisition unit 63 is connected to a wave radar attached to the hull 100, and acquires the sea state from the output value of the wave radar by a known method. The sea state acquisition unit 63 has a wireless communication function and acquires sea states from the outside.

The support unit 70 generates navigation support information for avoiding the occurrence of a load, using information about the load from the hull load observation device 10A, the ship speed from the ship speed acquisition unit 61, the rudder angle from the rudder angle acquisition unit 62, and the sea state from the sea state acquisition unit 63. Specifically, the navigation assistance information is information including a ship speed control and a rudder angle control for avoiding slamming that may become a load.

With such a configuration and performing such processing, navigation assistance for reducing the load can be performed.

In fig. 14, the hull load observation device 10A is shown as being used, but the hull load observation device 10 may be used.

In the hull load observation device described above, although the phenomenon that is a main cause of the load is mainly the detection of slamming or surging, the configuration using the hull load observation device 10A also allows the detection of the camber or sag of the hull.

Description of the reference numerals

10. 10A: ship load observation device

20. 20A, 20B, 20C, 20D: exercise state measuring unit

21: acceleration measuring unit

22: attitude measuring unit

30: extraction section

40: load calculation unit

50. 50A: data processing unit

61: ship speed acquisition unit

62: steering angle acquisition unit

63: sea state obtaining part

70: auxiliary part

80: navigation assistance system

100: boat hull

101: ship bow

102: stern of ship

110: steering room

201. 202, 203: antenna with a shield

204. 205, 206: receiving part

207: inertial sensor

208: an arithmetic unit.

Claims

1. A ship body load observation device is provided with:

an acceleration measuring unit for measuring the acceleration of the hull;

an attitude measuring unit for measuring an attitude of the hull;

an extraction unit that extracts, from the acceleration, a load-observing acceleration generated due to a phenomenon that is a factor causing a load on the hull by performing a filtering process on the acceleration, and extracts, from the attitude, a load-observing attitude generated due to the phenomenon by detecting a peak of a frequency of the attitude; and

and a load calculation unit that calculates the load using the acceleration for load observation and the posture for load observation.

2. The hull load observing apparatus of claim 1,

the load calculation unit calculates a load at a specific position of the hull using the load observation acceleration and the load observation attitude.

3. The hull load observing apparatus of claim 1 or 2,

the load calculation unit calculates a load index value from the acceleration for load observation and the posture for load observation, and calculates the load using an integrated value of the load index value.

4. The hull load observing apparatus of claim 3,

the extraction unit extracts the load-observation acceleration and the load-observation attitude at 2 or more times including any one of a time at which the phenomenon occurs, a time before the time, and a time after the time,

the load calculation unit calculates the load index value using at least one of a change amount or a change speed of the load observation acceleration and a change amount or a change speed of the load observation posture at the 2 or more times.

5. The hull load observing apparatus of claim 3,

the load calculation unit adds the load index value to the integrated value when the load index value exceeds a threshold value.

6. The hull load observing apparatus of claim 3,

the load calculation unit calculates the attitude of the hull and the direction and intensity of the acceleration applied to the hull at the attitude using the attitude for load observation and the acceleration for load observation, and calculates the load index value using the attitude of the hull and the direction and intensity of the acceleration applied to the hull at the attitude.

7. The hull load observing apparatus of claim 1 or 2,

the acceleration measuring unit and the posture measuring unit are constituted by a motion state measuring unit,

the exercise state measurement unit includes:

the antenna is arranged on the ship body and used for receiving a positioning signal;

an attitude measurement unit that calculates at least the attitude using a carrier phase of the positioning signal received by the antenna; and

and an inertial sensor provided in the hull and measuring at least the acceleration.

8. The hull load observing apparatus of claim 1 or 2,

the acceleration measuring unit and the attitude measuring unit are disposed at a plurality of positions of the hull,

the load calculation unit calculates the load for each of a plurality of positions of the hull.

9. The hull load observing apparatus of claim 8,

the load calculation unit synchronizes measurement times of the plurality of accelerometer units or the plurality of posture measurement units to calculate the load.

10. The hull load observing apparatus of claim 9,

the acceleration measuring unit and the attitude measuring unit are disposed at the same position, and the plurality of motion state measuring units are disposed on the hull,

the plurality of motion state measurement units each include:

an inertial sensor provided in the hull and measuring at least the acceleration,

the plurality of motion state measurement units perform the synchronization using the positioning signal.

11. The hull load observation device according to claim 1 or 2, further comprising:

and a detection unit that detects a time when the amount or rate of change of the acceleration exceeds an acceleration threshold value, or a time when the amount or rate of change of the attitude exceeds an attitude threshold value, as a time when a phenomenon that causes a load on the hull occurs.

12. The hull load observing apparatus of claim 1 or 2,

the phenomenon is slamming or surging of the hull.

13. A method for observing the load of a ship body,

the acceleration of the ship body is measured,

the attitude of the ship body is measured,

by performing filtering processing on the acceleration, a load-observing acceleration generated due to a phenomenon that becomes a main cause of a load on the hull is extracted from the acceleration,

extracting a posture for load observation due to the phenomenon from the posture by detecting a peak value of the frequency of the posture,

the load is calculated using the acceleration for load observation and the posture for load observation.

14. The hull load observing method of claim 13,

the time when the amount or rate of change of the acceleration exceeds the threshold value for acceleration or the time when the amount or rate of change of the attitude exceeds the threshold value for attitude is detected as the occurrence time of a phenomenon that is a factor causing the load of the hull.

15. A storage medium storing a ship load observation program for causing an arithmetic processing device to execute:

measuring the acceleration of the ship body;

measuring the attitude of the ship body;

extracting, from the acceleration, a load-observing acceleration generated due to a phenomenon that becomes a factor causing a load on the hull by performing filter processing on the acceleration;

extracting a load-observing attitude resulting from the phenomenon from the attitude by detecting a peak value of a frequency of the attitude; and

16. A storage medium storing a hull load observing program according to claim 15, the hull load observing program causing an arithmetic processing device to execute: