JPH026370Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a device for detecting motion acceleration of a moving object.
Specifically, the present invention relates to an acceleration detection device that can detect acceleration acting on any part of a moving body such as a ship, vehicle, or aircraft when the body moves. This is used, for example, in the field of investigating the influence of loaded cargo on a moving body by knowing the acceleration at a desired location.

[Prior art]

When a moving body carrying heavy cargo, such as a ship, rocks during navigation, acceleration acts on the hull structure or the loaded object, and as a result, a dynamic load is applied to the hull structure, the loaded object, and its supporting structure. work. As a result, it is necessary for the person planning the placement of the load and the ship operator to ensure that the load has a predetermined strength based on the response characteristics of the ship's hull to waves and long-term predictions of the wave and sea conditions that will be encountered. In other words, the layout planner takes into account the strength of the ship's hull structure when placing heavy objects and how to secure them, and the ship operator takes measures to avoid rough weather such as slowing down and changing course to avoid excessive dynamic loads during waves. need to be taken.

In such cases, if the dynamic load that actually acts can be detected, even more effective countermeasures can be taken. Therefore, in the past, several locations on the hull were determined in advance, and acceleration sensors were installed in three directions at each location. He is steering the ship. However, the acceleration that acts on each part of the ship and on each load is generally different, and even if excessive acceleration is applied at a location that is not measured, it is impossible to know. As a result, if the ship is maneuvered based on the detected values at several points, parts of the ship's hull may be damaged at points where excessive force is applied, or the lashing system for the cargo may be damaged, causing the cargo to collapse. A situation like this occurs. Therefore, in recent years, there has been a strong demand for a device that can arbitrarily detect acceleration acting on a ship's hull and cargo.

[Purpose of invention]

The present invention was developed in view of the above-mentioned needs, and its purpose is to detect the dynamic load acting on any part of the moving body or its payload in real time by detecting acceleration at a predetermined location on the moving body. It is an object of the present invention to provide a motion acceleration detecting device for a moving body that can display the motion acceleration of a moving body and obtain guidelines for changing a ship maneuvering method.

[Structure of the idea]

The configuration of the present invention will be explained with reference to FIG. 1. (i) A gyro 1 is mounted on the moving body 2 in order to detect the angle of motion of the moving body 2 or its angular velocity.

(ii) Amplifying means 3 for amplifying the output signal from this gyro 1 is provided.

(iii) Acceleration detection means 4 is provided, which is comprised of acceleration sensors 4ax, 4ay, and 4az placed at at least one position a in the space above moving body 2.

(iv) Amplifying means 5 for amplifying the output signal from the acceleration detecting means 4 is provided.

(v) Filter means 6 are provided for removing noise from the amplified acceleration signal.

(vi) An AD converter 7 is provided which digitizes the detection signals from the gyro 1 and the acceleration detection means 4.

(vii) Calculating means 8 is provided for calculating the acceleration at any position on the moving body 2 from the digitized signal.

(viii) Display means 9 for displaying the calculation results is provided.

〔Example〕

Hereinafter, the present invention will be described in detail based on examples thereof.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In the figure, 1 is a gyroscope mounted on the hull 2. For example, the pitch angle Θ due to the movement of the hull 2,
It detects motion angles in three directions: roll angle Φ and yaw angle Ψ. Reference numeral 3 denotes an amplifying means for amplifying the output signal from the gyro 1. Reference numeral 4 denotes acceleration detection means consisting of three acceleration sensors installed at one position a in the space above the hull 2. Note that the acceleration sensors 4ax, 4ay, and 4az are mounted at position a so as to detect acceleration in each of the three directions x, y, and z, as shown in FIG. 5 in Figure 1
are these three acceleration sensors 4ax, 4ay, 4az
6 is a filter means for removing noise from the amplified acceleration signal, and 7 is an AD converter for converting the detected analog signal into digital data so that it can be used for calculations. 8 indicates the hull 2 from the digitized signal.
This calculation means calculates the acceleration at any arbitrary position above and performs statistical processing calculations based on the calculated value. Reference numeral 9 denotes a display means such as a CRT for displaying the calculation results so that the vessel operator can check at a glance the magnitude of the acceleration and its change over time. Reference numeral 10 denotes a storage device in which accelerations allowed for various parts of the hull 2 and the load are stored in advance. Reference numeral 11 denotes an external storage device, which is a portable storage medium that accumulates and stores a large number of calculated values, and provides the data when the calculation means 8 performs statistical processing calculations. Reference numeral 12 denotes a printer, which is used to print out calculation results in order to save them.

Here, a method of calculating the acceleration at an arbitrary position using the detection values from the three acceleration sensors 4ax, 4ay, 4az and the gyro 1 at the aforementioned position a will be explained.

First, assume a hull-fixed coordinate system in which the bow direction of the hull is x, the width direction of the hull is y, and the vertical direction passing through the center of gravity of the hull is z. As a result, any position of the hull or payload is (x, y, z), the center of gravity of the hull is xG,
It is given by O,zG. Next, assume a spatially fixed coordinate system (X, Y, Z) on the hull. As shown in Figure 3 a to c, the amount of displacement in the coordinate system (X, Y, Z), that is, the amount of surge, which is movement in the front and back direction, is ζ, the amount of sway, which is movement in the left and right direction, is η, and the amount of up and down If the amount of heave, which is the movement in the direction, is ζ, the (X, Y, Z) components of the space-fixed coordinate system of the x, y, and z movements at arbitrary points on the ship are expressed by Equations 1-1 to 1.
-3 [see page 8].

Therefore, it is measured at arbitrary points x, y, and z.

X=ζ+(z-zG)Θ-yΨ...(1-1) Y=η+(x-xG)Ψ-(z-zG)Φ
…(1-2) Z=ζ−(x−xG)Θ+yΦ…(1−3) αx=ζ¨+(z−zG)Θ¨−yΨ¨−(x−xG)(Θ¨
² + ^Ψ¨2 )
+gΘ¨...(2-1) αy=η¨+(x-xG)Ψ¨-(z-zG)(Φ¨-y(
Φ〓 ² +
Ψ〓 ² )−gΦ …(2-2) αz=ζ¨+(x−xG)Θ¨+yΦ¨−(z−zG)(Θ〓
² +Φ〓 ² )
−gcosΘcosΦ…(2-3) αx=αxa+(z−za)Θ¨−(y−ya)Ψ¨−(x−
xa) (Θ〓 ² +Ψ〓 ² ) …(3-1) αy＝αya＋(x−xa)Ψ¨−(z−za)Φ¨−(y−y
a)
(Φ〓 ² +Ψ¨ ² ) …(3-2) αz＝αza−(x−xa)Θ¨+(y−ya)Φ¨−(z−z
a)
(Θ〓 ² +Φ¨ ² ) …(3-3) Ψ¨=(αyb−αya)/(xb−xa)…(4) Φ¨=(αyc−αya)/(za−zc)…(5− 1) Φ¨=(αzd-αza)/(yd-ya)...(5-2) Θ¨=(αzb-αza)/(xa-xb)...(6) Three directions of acceleration in the hull fixed coordinate system Component αx,
αy, αz are calculated using equations (2-1) to (2-3), considering the combination of gravitational acceleration g and centrifugal force around the center of gravity.
[See page 8] can be approximated. now,
When the accelerations αxa, αya, αza in three directions at point a are measured, from equations (2-1) to (2-3), the accelerations αx, αy, αz at any point (x, y, z) are calculated. is given by equations (3-1) to (3-3) [see page 8]. That is, αxa, αya, αza in equations (3-1) to (3-3) are substituted with the acceleration measured at position a (see Figure 2), and x-xa, y
The distance from the position a to the desired position is calculated and substituted for -ya and z-za. On the other hand, the yaw angular acceleration Ψ¨ of the hull, the roll angular acceleration Φ¨, the pitch angular acceleration Θ¨ and the yaw acceleration Ψ〓, the roll angular velocity Φ〓,
The angular velocity Θ of the pitch is obtained by first- and second-order differentiation from the yaw angle Ψ, roll angle Φ, and pitch angle Θ detected by the gyro 1, respectively, by the calculation means 8. These are the above-mentioned equations (3-1) to (3
-3), αx, αy, αz are obtained. Note that if the gyro 1 is a rate gyro, the yaw angular velocity Ψ〓, the roll angular velocity Φ〓, and the pitch angular velocity Θ〓 are directly detected, so their values and the first-order differential value thereof are substituted.

According to the embodiment of the above-described configuration and its calculation method, acceleration at an arbitrary location can be detected in the following manner. In order to facilitate understanding of the operation, the explanation will be made with reference to the flowchart shown in FIG. 4.

First, start up the system of the motion acceleration detection device (step 1 of the flowchart, hereinafter referred to as S1), and specify the arbitrary position (x, y, z) and measurement time you want to measure, as well as any necessary bibliographic information. The following items are set (S2). Acceleration sensors 4ax, 4ay, and 4az provided at position a detect respective acceleration signals (S3), each of which is amplified and filtered, and converted into a digital value by AD conversion means 7 (S4). On the other hand, at the same time, yaw angle Ψ, roll angle Φ, and pitch angle Θ are detected by gyro 1 (S5), and each is amplified and
It is converted into a digital value by the AD conversion means 7 (S
6). Then, the calculation means 8 calculates the formula (3-1) to
(3-3), (x,
Accelerations αx, αy, and αz in three directions at (y, z) are calculated (S7). This calculated acceleration is
It is displayed on the CRT screen together with the allowable acceleration at that position stored in the storage device 10. Also, when time history plotting is commanded as necessary (S8), the specified position (x,
y, z) are displayed in real time over time (S9). In this way, the acceleration at different arbitrary positions is displayed one after another to confirm whether the acceleration is permissible at each position, and if necessary, the ship maneuvering method is changed to reduce the acceleration. In addition, these data are compared with previous data at the same position stored in the external storage device 11, and a significant value, 1/3 maximum expected value, etc. are statistically calculated in the calculation means 8 (S10 ), this calculated value is also displayed on the CRT as necessary (S11). The detected data is logged in the external storage device 11 (S1
2) Also, logging items are printed out as necessary (S13). Then, based on the statistically processed data, the cargo placement planner can consider whether or not the cargo placement and lashing method for the next voyage should be improved. Furthermore, hull designers can also use the data to design the strength of the hull structure. Note that acceleration at any position can be detected using at least three acceleration sensors installed at one location a, but it is possible to increase detection accuracy by installing a plurality of acceleration sensors in each of the three directions at location a. It can also be improved.

By the way, in the above example, a three-direction detection gyroscope was used to detect the pitch angle Θ, roll angle Φ, yaw angle Ψ, or their angular velocities Θ〓, Φ〓, Ψ〓, which are the hull movements. It is something that detects the roll angle Φ or its angular velocity Θ〓, Φ〓,
If the angle or angular velocity in only one direction is to be detected, the acceleration at any location can be measured as follows. As the acceleration detection means 4, for example, as shown in FIG.
In a vertical plane including different first and second points a and b selected in the longitudinal direction (i.e.
A third point c is on the line B that is perpendicular to the line A connecting and point b.
Acceleration sensors 4ax, 4ay, 4 detect acceleration in the x, y, and z directions at position a, which is set as a reference point.
az, and acceleration sensors 4by and 4bz that detect acceleration in the y and z directions at another point b in the longitudinal direction,
An acceleration sensor 4cy for detecting acceleration in the y direction is installed at the third point c. That is, hull 2
The assumed coordinate system and the arrangement of the respective motion and acceleration sensors are shown in FIGS. 6a to 6c. Then, six acceleration sensors 4ax, 4ay, 4az, 4by,
The acceleration at an arbitrary position is calculated using the detected values by 4bz and 4cy. Now, if the accelerations αxa, αya, αza in three directions at point a are measured, then the accelerations αx, αx, and αza at any point (x, y, z) are measured.
αy, αz are the formulas (3-1) to (3-3) [8
page reference]. That is, the formula (3-
αxa, αya, αza in 1) to (3-3) are
Acceleration measured at position a (see Figure 5)
is assigned, and x-xa, y-ya, z-za are at position a
The distance from to the desired position is calculated and substituted. On the other hand, as can be seen from Figure 5, the yaw angular acceleration Ψ¨ is calculated at two points a and b where (y, z) are the same but x is different.
From the measured accelerations αya and αyb at
From the measured accelerations αya and αyc at c, the angular acceleration Θ¨ of the pitch can be calculated from two points a, where (y, z) are the same and x is different.
From the measured accelerations αza and αzb at b, equations (4) and
(5-1), (6) [see page 8], and the yaw angular velocity Ψ〓, roll angular velocity Φ〓 and pitch angular velocity Θ〓 are the calculated yaw angular acceleration Ψ¨, roll angular acceleration Φ¨ and pitch angular acceleration Θ¨ are calculated by calculation means 6
It is calculated by integrating. Then, when these are substituted into the above equations (3-1) to (3-3),
αx, αy, αz are obtained. As shown in FIG. 5, if the acceleration sensor 4dz is provided at position d in the horizontal plane instead of position c, the angular acceleration Φ¨ of the roll described above will be as follows with (x, z) being the same and y being the same. From the measured accelerations αza and αzd at two different points a and d, the formula (5
-2) is calculated. Therefore, by such calculation, it is possible to measure the acceleration at any location without using a gyro. Conversely,
If a gyroscope for detecting any angle or its angular velocity is provided, a part of the above-mentioned acceleration sensor will be unnecessary, and therefore, the corresponding calculation will also be unnecessary. That is, when the gyro detects the pitch angle Θ or its angular velocity Θ〓, the acceleration sensors 4az and 4bz that detect the accelerations αza and αzb are unnecessary, and the gyro detects the roll angle Φ or its angular velocity Φ〓. acceleration αya, αyc or acceleration αza,
Acceleration sensor 4ay, 4cy or 4 that detects αzd
az, 4dz are no longer required, and if the gyro detects the yaw angle Ψ or its angular velocity Ψ〓, the acceleration sensor 4 that detects the accelerations αya, αyb
ay and 4by are no longer necessary. Of course, if the gyro detects angles in any two directions or their angular velocities, the corresponding acceleration sensors described above are not required. This has the advantage that it is not necessary to use an expensive gyroscope that can detect in three directions.

Note that detection accuracy can also be improved by installing a plurality of acceleration sensors in a predetermined direction at each position. Additionally, if the hull is a rigid body, only one set of the above-mentioned sensors is required, but if the hull is elastically deformed and behaves differently at the bow, mid-hull, and stern, one set may be installed for each. , more accurate acceleration can be detected in each part. It goes without saying that the above-mentioned detection using the gyroscope and acceleration sensor can be applied not only to the hull but also to all moving bodies such as vehicles and aircraft.

[Effect of idea]

As can be seen from the description of the embodiments above, the present invention has the following features:
Calculates the acceleration at any position on the ship body based on the detection signal of the acceleration detection means consisting of three acceleration sensors provided at at least one place on the moving body and the motion angle or its angular velocity detected by the gyroscope. be able to. Therefore, it is possible to change the ship maneuvering method according to the acceleration displayed in real time, and on ships carrying heavy cargo, it is easier to arrange the cargo and select the lashing method, which improves navigation safety. can be achieved.

[Brief explanation of the drawing]

Figure 1 is a configuration block diagram of the motion acceleration detection device, Figure 2 is a measurement state diagram showing the acceleration sensor installed on the hull and its measurement direction, and Figures 3 a to c are the coordinate systems assumed for the hull, respectively. FIG. 4 is a flowchart showing the operation procedure,
Figure 5 is a measurement state diagram showing the acceleration sensor installed on the hull and its measurement direction, and Figures 6 a to c show the coordinate system assumed for the hull, each movement, and the installation status of the acceleration sensor at three locations. It is a schematic diagram. 1...Gairo, 2...Moving body (hull), 33,
5...Amplifying means, 4...Acceleration detection means, 4ax,
4ay, 4az, 4by, 4bz, 4cy, 4dz... acceleration sensor, 6... filter means, 7... AD converter, 8... calculation means, 9... display means, a to d...
…position.

Claims (1)

[Claims for Utility Model Registration] A gyroscope mounted on a movable body to detect the angle of motion of the movable body or its angular velocity; an amplifying means for amplifying the output signal from the gyroscope; and at least one location in a space above the movable body. an acceleration detection means comprising an acceleration sensor installed at a position; an amplification means for amplifying the output signal from the acceleration detection means; a filter means for removing noise from the amplified acceleration signal; and the gyro and the acceleration detection means. An AD converter that digitizes the detection signal from the digitized signal, a calculation means that calculates the acceleration at an arbitrary position on the moving body from the digitized signal, and a display means that displays the calculation result. A device for detecting the motion acceleration of a moving object.