Impact meters, falling object impact meters, and raindrop impact meters

Abstract

The present invention provides a raindrop impact meter for measuring the impact force of impacting objects, including raindrops; a falling object impact meter for measuring the impact force of falling objects; and a raindrop impact meter for measuring the impact force of raindrops. [Solution] The raindrop impact meter M, which is an example of an impact meter and an example of a falling object impact meter, comprises a raindrop impact detector 1 having a 3-axis acceleration sensor, and a control unit of a second computer 32 that obtains the raindrop impact force based on the combined acceleration obtained by combining the accelerations of each axis. The raindrop impact detector 1 is an example of an impact detector and an example of a falling object impact detector. The raindrop impact detector 1 has a raindrop receiving section 2 that receives raindrops. The raindrop receiving section 2 is an example of a receiving section. The upper surface of the raindrop receiving section 2 is rounded and convex upwards. The lower surface of the raindrop receiving section 2 is flat. The acceleration sensor is attached to the lower surface of the raindrop receiving section 2.

Description

【Technical Field】 【0001】 The present disclosure relates to a shock meter for measuring the impact force of a collision object such as a raindrop, a falling object shock meter, and a raindrop shock meter. 【Background Art】 【0002】 As a rainfall sensor, one described in Japanese Patent Application Laid-Open No. 2018-173342 (Patent Document 1) is known. This rainfall sensor has a vibrating body that vibrates due to the impact of raindrops, an acceleration sensor provided on the vibrating body, and a transmission interface that transmits acceleration data from the acceleration sensor. The acceleration data is used for estimating the rainfall in a rainfall estimation device. The rainfall estimation device has means for performing a Fourier transform on the acceleration data into data in the frequency domain for each time period, means for extracting feature data consisting of correlation values between the data in the frequency domain, and means for estimating the rainfall from the feature data using a regression formula obtained by machine learning for the rainfall sensor. 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2018-173342 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 Although the above rainfall sensor and rainfall estimation device estimate the rainfall from acceleration data, they do not obtain the impact force of raindrops. 【0005】 The main object of the present disclosure is to provide a shock meter for measuring the impact force of a collision object such as a raindrop, a falling object shock meter for measuring the impact force of a falling object, and a raindrop shock meter for measuring the impact force of a raindrop. 【Means for Solving the Problems】 【0006】 This specification discloses an impact meter. This impact meter may include an impact detector having a three-axis acceleration sensor. The impact meter may also include a control unit that obtains an impact force based on a combined acceleration obtained by combining the accelerations of each axis. Furthermore, this specification discloses a falling object impact meter. This falling object impact meter may include a falling object impact detector having a three-axis acceleration sensor. The falling object impact meter may also include a control unit that obtains a falling object impact force based on a combined acceleration obtained by combining the accelerations of each axis. Moreover, this specification discloses a raindrop impact meter. This raindrop impact meter may include a raindrop impact detector having a three-axis acceleration sensor. The raindrop impact meter may also include a control unit that obtains a raindrop impact force based on a combined acceleration obtained by combining the accelerations of each axis. 【Advantages of the Invention】 【0007】 The main advantage of the present disclosure is to provide an impact meter capable of measuring the impact force of a colliding object such as a raindrop, a falling object impact meter capable of measuring the impact force of a falling object, and a raindrop impact meter capable of measuring the impact force of a raindrop. 【Brief Description of the Drawings】 【0008】 [Figure 1] It is a perspective view of the upper surface, rear surface, and right side of a raindrop impact detector belonging to a raindrop impact meter according to the first embodiment of the present disclosure. [Figure 2] It is a perspective view of the lower surface, front surface, and left side of the raindrop impact detector of FIG. 1. [Figure 3] It is a schematic top view of a raindrop impact meter including a plurality of the raindrop impact detectors of FIG. 1. [Figure 4] It is a flowchart related to an operation example of the raindrop impact meter. [Figure 5] It is a graph showing an example of changes in each acceleration when there is a raindrop impact, and is a graph when the x acceleration Ax and the y acceleration Ay are large. [Figure 6] ]]It is a graph showing an example of changes in each acceleration when there is a raindrop impact, and is a graph when the z acceleration Az is large. [Figure 7] This graph shows the average (G) of the maximum acceleration values ​​for x-acceleration Ax, y-acceleration Ay, z-acceleration Az, and combined acceleration As for each different raindrop collision position on the x-axis. [Figure 8] This graph shows the sum of the maximum acceleration values ​​(G) for each of the following: x-acceleration Ax, y-acceleration Ay, z-acceleration Az, and combined acceleration As, for each of the two different raindrop collision locations on the x-axis. [Figure 9] These are perspective views of the top, rear, and right side of a raindrop impact detector belonging to the second embodiment of the raindrop impact meter described herein. [Figure 10] Figure 9 shows perspective views of the raindrop impact detector from the bottom, front, and left side. [Figure 11] These are perspective views of the top, rear, and right side of a raindrop impact detector belonging to the third embodiment of the raindrop impact meter described herein. [Figure 12] Figure 11 shows perspective views of the raindrop impact detector from the bottom, front, and left side. [Figure 13] Figure 11 is a schematic top view of a raindrop impact meter that includes multiple raindrop impact detectors. [Figure 14] This graph shows examples of changes in the combined acceleration As(G) when various objects fall and cause impact. [Modes for carrying out the invention] 【0009】 The embodiments and modifications thereof relating to this disclosure will be described below with reference to the drawings as appropriate. This disclosure is not limited to the following forms and variations. 【0010】 [First form] Figure 1 is a perspective view of the top, rear, and right side of the raindrop impact detector 1 belonging to the raindrop impact meter M according to the first embodiment. Figure 2 is a perspective view of the bottom, front, and left side of the raindrop impact detector 1 of Figure 1. The thin solid lines in Figures 1 and 2 (excluding the leader lines of the symbols) are used to identify the shape of the three-dimensional surface. Raindrop impact meter M is an example of an impact meter, and is an example of a falling object impact meter. Raindrops are an example of falling objects. Raindrop impact detector 1 is an example of an impact detector, and is an example of a falling object impact detector. The first form of the raindrop impact detector 1 comprises a drip receiving section 2, a sensor section 4, and multiple (in this case, tripod) legs 6. The legs 6 may consist of one to two legs, or four or more legs. For convenience, the various directions of the raindrop impact detector 1 are as shown in each figure. However, these directions may be changed as appropriate by movement due to the driving of a component or part, and by at least one of the installation postures. The raindrop impact detector 1 is a device that measures the impact force of raindrops. 【0011】 One example of a receiving part is the drip-receiving part 2, which is made of resin, specifically polytetrafluoroethylene (PTFE). However, the material of the drip-receiving part 2 may be other than PTFE. The drip receiving section 2 is dome-shaped. The drip receiving section 2 may also be composed of multiple integrated parts. The upper surface of the drip-receiving section 2, which serves as the first surface, is rounded and convex outward, i.e., upward. If the upper surface of the drip-receiving section 2 is rounded and convex upward, water is less likely to accumulate in the drip-receiving section 2 compared to when the upper surface is flat or concave downward. Also, if the upper surface of the drip-receiving section 2 is rounded and convex upward, it is easier to transmit the force originating from raindrops to the sensor section 4 compared to when the upper surface is conical. Furthermore, if the upper surface of the drip-receiving section 2 is rounded and convex upward, it will have a certain thickness at least in the radial center, making it easier to transmit the force originating from raindrops to the sensor section 4 compared to when the drip-receiving section 2 is film-like. Note that the shape of the upper surface of the drip-receiving section 2 is not limited to a dome shape. The lower surface of the drip-receiving section 2, which serves as the second surface, is flat, making it easier to mount the sensor section 4 in a manner appropriate for detecting the force originating from raindrops, compared to a curved surface. The upper surface of the drip-receiving section 2, which serves as the first surface, faces the lower surface, which serves as the second surface. However, the shape of the lower surface of the drip-receiving section 2 is not limited to a flat surface. Also, the first surface and the second surface do not have to face each other. Furthermore, the first surface may be other than the upper surface, and the second surface may be other than the lower surface. For example, if the raindrop impact detector 1 is installed with the flat second surface at an angle to the horizontal plane, it will be possible to detect the impact of lateral raindrops when they are received by the first surface of the drip-receiving section 2. A sensor mounting portion 10 is provided in the center of the lower surface, which is the second surface of the drip receiving portion 2. The sensor mounting portion 10 is a recess that is recessed upward in a thin plate shape relative to the adjacent portion. Note that the shape of the sensor mounting portion 10 does not have to be thin plate-shaped, nor does it have to be a recess. Also, the placement of the sensor mounting portion 10 does not have to be in the center of the lower surface. 【0012】 The sensor unit 4 includes an acceleration sensor. The sensor unit 4 is attached to the sensor mounting portion 10 of the drip receiving portion 2. The acceleration sensor in sensor unit 4 detects acceleration in three axes. These three axes are the x-axis, y-axis, and z-axis. The x-axis runs in the left-right direction. The y-axis runs in the front-back direction. The z-axis runs in the up-down direction. The x-axis, y-axis, and z-axis are orthogonal to each other. The origins of the x-axis, y-axis, and z-axis are located in sensor unit 4. The z-axis passes through the center of the upper surface of the drip receiving unit 2. On the x-axis, x to the left of the origin is a negative value. On the y-axis, y behind the origin is a negative value. On the z-axis, z below the origin is a negative value. The acceleration along the x-axis is denoted as x-acceleration. The acceleration along the y-axis is denoted as y-acceleration. The acceleration along the z-axis is denoted as z-acceleration. Furthermore, the three axes are not limited to those relating to the x, y, and z axes as described above. For example, x values ​​to the right of the origin on the x-axis may be negative, y values ​​in front of the origin on the y-axis may be negative, z values ​​above the origin on the z-axis may be negative, the x-axis may be aligned in the front-to-back direction and the y-axis in the left-to-right direction, or a polar coordinate system may be used. 【0013】 Each leg portion 6 has a leg body 20 and a foot portion 22. Each leg body 20 extends vertically and is mounted below the drip receiving section 2, radially outward from the sensor mounting section 10, and arranged at equal intervals in the circumferential direction. However, the arrangement of each leg body 20 is not limited to this configuration. Each foot portion 22 is provided at the lower end of the corresponding leg body 20. Each foot portion 22 protrudes radially outward from the lower end of the corresponding leg body 20. The shape of some or all of the foot portions 22 may be other than a radially outward protruding shape. Also, some or all of the foot portions 22 may be omitted. 【0014】 Figure 3 is a schematic top view of the raindrop shock meter M. The raindrop impact meter M comprises multiple (19 in this case) raindrop impact detectors 1, a first computer 30 (first COM), and a second computer 32 (second COM). Furthermore, the number of raindrop impact detectors 1 may be between 1 and 18, or between 20 and 20. 【0015】 The drip receiving section 2 of each raindrop impact detector 1 is positioned a predetermined distance above the installation surface via the legs 6. In this case, the installation surface is the horizontal surface of the top of a stand placed on the ground. The installation surface may also be the ground, the top surface of an object other than a stand, a slope, or a curved surface. Each raindrop impact detector 1 is arranged in a regular pattern. However, some or all of the raindrop impact detectors 1 may be arranged irregularly. More specifically, each raindrop impact detector 1 is arranged such that, when viewed from above to below, the centers of adjacent detectors are located at the vertices of a virtual equilateral triangle. However, the arrangement of some or all of the raindrop impact detectors 1 may differ from that of such an equilateral triangle. In Figure 3, the leftmost raindrop impact detector 1 is numbered 01, the raindrop impact detector 1 to its right and rear is numbered 02, the one further to its right and rear is numbered 03, the one to the right and in front of number 01 is numbered 04, and so on up to number 19. Note that the numbers, i.e., the identification information for each raindrop impact detector 1, may be assigned in a different manner, or may not be assigned at all. Furthermore, above each of the raindrop impact detectors 1 numbered 08 to 12, a frame FR, which serves as a girder in a transmission tower, is placed. Note that the frame FR may belong to a transmission tower for distribution lines, to a tower for other purposes, or to other artificial or natural structures. Also, a frame FR may pass above raindrop impact detectors 1 of other numbers. Alternatively, in place of the frame FR, or together with the frame FR, other artificial or natural structures may be placed above some or all of the raindrop impact detectors 1, or shielding objects may be placed, or nothing may be placed above them, including the frame FR. An example of a natural structure is, for example, a tree. Furthermore, the front-to-back direction may be north-south, east-west, or a direction deviating from the north-south or east-west direction. 【0016】 The first computer 30 is a portable microcontroller and is located adjacent to each raindrop impact detector 1. However, the first computer 30 may be a non-portable, i.e., stationary computer, or it may not be a microcontroller, or it may be located in a position other than adjacent to each raindrop impact detector 1. The first computer 30 includes an input unit, an output unit, a memory, a memory writing unit, a position information unit, a clock unit, and a control unit. The input section is the part that receives information, and is, for example, at least one of a switch, keyboard, pointing device, or the receiving section of a communication unit. The output section is the part that outputs information, and is, for example, at least one of a lamp, monitor, speaker, or the transmission section of a communication unit. Memory is the part that stores information, and in this case, it is a portable memory card. Note that other forms of memory may be used instead of, or in conjunction with, the memory card. The memory writing unit, in this context, is the unit that writes information to the memory card. The location information unit is the part that acquires location information using the Global Positioning System (GPS), which belongs to the Global Navigation Satellite System (GNSS). The location information unit may acquire location information from other GNSS systems instead of GPS, or in conjunction with GPS. Alternatively, the location information unit may acquire location information from sources other than satellites, such as cell phone base stations. The clock section is the part that holds the date and time information. The control unit is responsible for controlling other parts of the first computer 30 and processing information; in this case, it is the CPU. However, the control unit may be something other than the CPU. Furthermore, the part that controls other parts and the part that processes information may be separate components. Furthermore, two or more parts may be integrated, such as by providing a touch panel that serves as both an input and output unit, or by having the memory writing unit and memory as internal memory. Also, the first computer 30 may be provided in multiple, distributed configurations that enable cooperation. 【0017】 The first computer 30 is wirelessly connected to the sensor unit 4 of each raindrop impact detector 1. Furthermore, the first computer 30 may be connected to each raindrop impact detector 1 via wired communication. 【0018】 The second computer 32 is a portable laptop computer and may be placed adjacent to each raindrop impact detector 1, or in offices, workshops, etc. The first computer 30 may be a non-portable computer, a desktop computer or other type of computer, or may be placed in various locations other than those mentioned above. The second computer 32, like the first computer 30, has an input unit, an output unit, a memory, a memory writing unit, and a control unit. The second computer 32 may also further include at least one of a position information unit and a clock unit. Furthermore, the second computer 32 may have modifications similar to those of the first computer 30 as appropriate. In addition, the first computer 30 and the second computer 32 may be integrated, or they may be distributed across three or more computers. 【0019】 The second computer 32 is wirelessly connected to the first computer 30. Furthermore, the second computer 32 may be connected to the first computer 30 via wired communication. Alternatively, the second computer 32 may receive information stored in the first computer 30 by inserting a memory card removed from the first computer 30, either in lieu of or in conjunction with communication. In addition, the second computer 32 may be connected to some or all of the raindrop impact detectors 1 in a communication-enabled manner. 【0020】 In response to raindrops colliding with the drip-receiving section 2, the x-accelerometer, y-accelerometer, and z-accelerometer detected by the 3-axis acceleration sensor of the sensor section 4 change. The control unit of the first computer 30 acquires the x-acceleration, y-acceleration, and z-acceleration from the acceleration sensor of each raindrop impact detector 1 via communication at predetermined timings and stores them appropriately in the memory card. The timing may be, for example, a frequency of 1000 times per second (s), or at unequal intervals, each time a predetermined condition is met, or an appropriate combination thereof. Note that the frequency is not limited to 1000 times / s. The control unit of the second computer 32 calculates the x-acceleration A for each axis stored in the memory card of the first computer 30. x , y-acceleration A y , z acceleration A z In this case, the composite acceleration A s This is calculated based on the following equation (1). Then, the second computer 32 calculates the combined acceleration A sBased on this, the impact force of the raindrop is determined. Note that the combined acceleration A s At least one of the impact force of the raindrops may be determined by the first computer 30. 【0021】 【number】 【0022】 An example of the operation of such a raindrop shock meter M is described below. Figure 4 is a flowchart illustrating an example of the operation of the raindrop shock meter M. 【0023】 The control unit of the first computer 30 first activates the location information unit (step S1). Next, the first computer 30 assigns a set value to the acceleration sensor for each sensor unit 4 and transmits it. The first computer 30 also sends a command to each sensor unit 4 to perform zero-point correction, thereby causing it to perform zero-point correction (step S2). 【0024】 Next, the control unit of the first computer 30 starts the memory writing unit (step S3). Furthermore, the control unit of the first computer 30 acquires location information using the location information unit and stores it in the memory card, updates the internal clock, and creates a save file on the memory card to store the information (step S4). 【0025】 Then, the first computer 30 performs a "measurement" loop process. In this loop process, first, the control unit of the first computer 30 determines whether a predetermined time (6 hours in this case) has elapsed since the acquisition of location information (step S5). If the answer in step S5 is Yes, the control unit reacquires location information, updates the internal clock (step S6), and proceeds to step S7. On the other hand, if the answer in step S5 is No, the control unit proceeds to step S7 without executing step S6. Steps S5 and S6 correct any positional information deviations and internal clock deviations that may occur due to the passage of a predetermined time, thereby improving the accuracy of each. Note that at least one of the steps of reacquiring positional information and updating the internal clock may be omitted. 【0026】 Next, the control unit of the first computer 30 acquires x-acceleration, y-acceleration, and z-acceleration data from the acceleration sensors of each sensor unit 4 via communication (step S7). Each acceleration data or combination thereof is assigned the number of the corresponding raindrop impact detector 1. For ease of understanding, the following description will mainly focus on data processing related to one raindrop impact detector 1. Unless otherwise specified, the data processing related to each raindrop impact detector 1 is the same as the data processing described below. Next, the control unit of the first computer 30 determines whether at least one of the absolute values ​​of x acceleration, y acceleration, and z acceleration falls below a threshold (step S8). If the control unit determines No in step S8, it returns to the beginning of the loop processing (step S5). On the other hand, if the control unit determines Yes in step S8, it proceeds to step S9. 【0027】 In step S9, the control unit of the first computer 30 determines whether at least one of the x acceleration, y acceleration, and z acceleration has been below the threshold for a predetermined number of consecutive times (nth time). Here, n = 4. If the result in step S9 is No, the control unit stores the x-acceleration, y-acceleration, and z-acceleration data into the memory card (step S10) and returns to the beginning of the loop processing. On the other hand, if the control unit responds YES in step S9, it proceeds to step S11. In step S11, the control unit of the first computer 30 writes the stored acceleration data and the corresponding date and time information to the memory card. 【0028】 Next, the control unit proceeds to step S12 and determines whether the number of data items to be written is greater than or equal to a predetermined number (a items). Here, a = 50000. When the control unit of the first computer 30 is Yes in step S12, it closes the current saved file, creates a new saved file (step S13), and returns to the beginning of the loop process. Steps S12 to S13 suppress the situation where the size of the saved file becomes excessive and an error occurs. On the other hand, when the control unit is No in step S12, it returns directly to the beginning of the loop process. 【0029】 Figures 5 and 6 are graphs showing examples of changes in each acceleration when there is an impact of raindrops. Figure 5 relates to the case where the x acceleration A x and the y acceleration A y are large, and Figure 6 relates to the case where the z acceleration A z is large. In Figures 5 and 6, the x acceleration, y acceleration, and z acceleration are acquired at a frequency of 1000 times / s. In Figures 5 and 6, the horizontal axis is time (milliseconds), and the vertical axis is acceleration (G) with the unit of gravitational acceleration. Note that the unit of acceleration does not have to be G, and for example, it may be m / s 2 . As shown in Figures 5 and 6, the combined acceleration A s is large immediately after the raindrop collides with the droplet receiving part 2 and decays over time. 【0030】 The combined acceleration A s rarely becomes zero, and even when there is no impact of raindrops, it exists almost constantly, albeit slightly, due to at least one of fine vibration, noise of the acceleration itself, and noise of the first computer 30. Therefore, when at least one of the absolute values of the x acceleration, y acceleration, and z acceleration from the raindrop impact detector 1 is less than the threshold value n times continuously by the threshold-based process (steps S8 to S11) of the control unit of the first computer 30, the x acceleration, y acceleration, and z acceleration are not stored hereafter until a new value above the threshold value occurs. The threshold value is obtained experimentally and / or theoretically in advance. In Figures 5 and 6, an example of the threshold value is shown by a dashed-dotted line. Through this process, the impact force of raindrops below a predetermined raindrop impact energy is ignored by the raindrop impact meter M. Therefore, the situation in which the impact force of raindrops is determined from acceleration data caused by at least one of the following: minute vibrations not based on collisions with raindrops, noise from the acceleration itself, and noise from the first computer 30 is suppressed. In addition, the computational load on the first computer 30 and the second computer 32 is reduced, resulting in power savings. Furthermore, strictly speaking, the impact force of extremely small raindrops, such as those in a light drizzle, may not be obtainable due to the setting of such a threshold. However, when it is necessary to understand the impact force of raindrops, such as when analyzing soil erosion caused by raindrops, it is necessary to obtain the impact force of raindrops that can exert an effect of a certain degree or more. Therefore, it is not a problem if the impact force of extremely small raindrops cannot be obtained due to the setting of the threshold. Also, from this viewpoint, the raindrop impact meter M is preferably used for soil erosion analysis. 【0031】 The control unit of the second computer 32 controls the composite acceleration A s The equivalent acceleration A is calculated using equation (1), and here we have the equivalent acceleration A. s The raindrop impact force is determined from the maximum value. 【0032】 The force F exerted by the impact of raindrops on the drip-receiving part 2 can be calculated using the following equation (2), where m (kg) is the mass of the drip-receiving part 2. 【0033】 【number】 【0034】 The work W (N·m) done by a raindrop upon impact is given by the force F and the deformation distance d of the drip-receiving part 2, as shown in equation (3). The deformation distance d is a constant determined by the material, shape, etc., of the drip-receiving part 2. Also, as shown in equation (3), the work W is equal to the change in the kinetic energy E of the raindrop. 【0035】 【number】 【0036】 Substituting equation (2) into equation (3) yields equation (4), which can be further transformed to obtain equation (5). 【0037】 【number】 【number】 【0038】 If the rigidity and elastic properties of the drip receiving part 2 are constant, the impact position of the raindrop is constant relative to the sensor, the contact time (the time the raindrop is in contact with the drip receiving part 2 at the impact point) is constant, the transmission time (the time it takes for the impact to be transmitted from the raindrop to the drip receiving part 2 at the impact point) is constant, and the shape of the drip receiving part 2 does not affect the impact transmission characteristics, then the composite acceleration A s This is proportional to the change in the kinetic energy of the raindrop, E, i.e., the impact energy of the raindrop. In reality, the proportionality constant 1 / md in equation (5) is not constant due to the attenuation of the impact force within the drip-receiving section 2, changes in the collision position, etc. This change in the proportionality constant due to changes in the collision position, etc., is known in advance by performing calibration and taken into account when measuring the raindrop impact force. In this way, the control unit of the second computer 32 determines the change in the kinetic energy E of the raindrop, i.e., the raindrop impact force, and stores it in memory. 【0039】 Furthermore, the collision position of a raindrop in one of the drip receiving sections 2 can be determined by the second computer 32, for example, as follows. Alternatively, the collision position of the raindrop may also be determined by the first computer 30. 【0040】 The closer the raindrop impact point is to the center of the upper surface of the raindrop receiving section 2, the less loss there is in transmitting the raindrop impact force to the sensor section 4. The further the raindrop impact point is from the center of the upper surface of the raindrop receiving section 2, the greater the loss in this transmission, resulting in a corresponding decrease in x, y, and z acceleration. The angle θ of the collision position relative to the x-axis is given by the x-acceleration A. x and y-acceleration A y Therefore, it can be expressed by the following equation (6). 【0041】 【number】 【0042】 And the distance d from the center of the upper surface of the droplet receiving part 2 at the collision point. c is x-acceleration A x , y-acceleration A y and z-accelerometer A z The constant K is expressed by the following equation (7). The constant K depends on the material properties and vibration transmission characteristics of the drip receiving section 2. 【0043】 【number】 【0044】 The angle θ and distance d related to the collision position are as follows: c If this is known, the magnitude of the damping of the x, y, and z accelerations corresponding to these can be determined. Therefore, the control unit of the second computer 32 can correct at least one of the x, y, and z accelerations based on the magnitude of the damping, and by using the appropriately corrected x, y, and z accelerations, the raindrop impact force can be measured with greater accuracy. 【0045】 The following tests were conducted to determine how various accelerations change at different raindrop collision locations in the drip-receiving section 2. Specifically, the tester set up the drip receiving unit 2 with the sensor unit 4 horizontally in a room, and dropped water droplets with a diameter of 4.35 mm from a height of 2.5 m onto various positions on the upper surface of the drip receiving unit 2. These positions were -8 cm, -6 cm, -4 cm, -2 cm, 0 cm (also on the z axis), 2 cm, 4 cm, 6 cm, and 8 cm on the x-axis. The tester dropped 50 water droplets onto each impact position, and for each impact, the x-accelerometer A of the sensor unit 4 was measured. x , y-acceleration A y , z acceleration A zThe data is acquired, received by the first computer 30, and the combined acceleration A is processed by the second computer 32. s The tester calculated the average of the maximum values ​​of various accelerations (m / s²). 2 ) and the sum of the maximum values ​​of various accelerations (m / s²). 2 ) was sought. Furthermore, in this test, x-acceleration A x , y-acceleration A y , and z-accelerometer A z None of them have been corrected. 【0046】 Figure 7 shows the x-accelerometer A for each of the different raindrop collision locations on the x-axis. x , y-acceleration A y , z acceleration A z , and combined acceleration A s This graph shows the average (G) of the maximum acceleration values ​​related to [the event]. Figure 8 shows the x-acceleration A for each of the different raindrop collision positions on the x-axis. x , y-acceleration A y , z acceleration A z , and combined acceleration A s This graph shows the sum of the maximum acceleration values ​​(G) related to [the specified event]. Figures 7 and 8 show that the degree of attenuation of various accelerations originating from raindrops of the same size, depending on the collision position, can be determined in the raindrop receiving section 2 of the first embodiment of the raindrop impact detector 1. The degree of attenuation at different collision positions, which has been determined in advance, is x acceleration A x , y-acceleration A y , z acceleration A z This can be used as a calibration in the correction process. Furthermore, the determination of the degree of damping related to various accelerations for calibration may be performed outdoors, or along at least one of the y-axis and diagonal axes, either in place of or in conjunction with the x-axis, or under conditions different from the above test. 【0047】 The second computer 32 can measure the impact force of each raindrop, while knowing the collision location, using the x, y, and z accelerations from each raindrop impact detector 101. Therefore, users of the raindrop impact meter M can understand the distribution of raindrop impact force over a sufficient range at the measurement point and analyze the effects of raindrops at the measurement point. For example, the raindrop impact meter M measures and analyzes whether the raindrop impact force is strong directly below the frame FR of the transmission tower, strong at a predetermined distance from directly below the frame FR to one or both sides in the width direction of the frame FR, or strong directly below enlarged parts such as the joints of the frame FR. Based on such measurements and analyses, the user can plan countermeasures such as soil improvement work in areas with strong raindrop impact force, installation of structures such as roofs to mitigate the raindrop impact force, greening in areas with relatively weak raindrop impact force, or an appropriate combination of these measures. Furthermore, the user can actually implement countermeasures such as carrying out soil improvement work. 【0048】 The raindrop shock meter M described above provides the following effects: In other words, the raindrop impact meter M comprises a raindrop impact detector 1 having a sensor unit 4 including a 3-axis acceleration sensor, and a control unit of a second computer 32 that obtains the raindrop impact force based on the combined acceleration obtained by combining the accelerations of each axis. Therefore, a raindrop impact meter M is provided to measure the impact force of raindrops. 【0049】 Furthermore, the raindrop impact detector 1 has a raindrop receiving section 2. The upper surface of the raindrop receiving section 2, which serves as the first surface, is rounded and convex upwards. Therefore, by receiving raindrops in the dome-shaped raindrop receiving section 2, the impact is appropriately transmitted to the acceleration sensor, and the accumulation of raindrops in the raindrop receiving section 2 is suppressed. Consequently, the raindrop impact meter M can obtain the three-axis acceleration of the raindrop with high accuracy, and the raindrop impact force can be measured with high accuracy. In addition, the lower surface of the drip-receiving section 2, which is the second surface facing the first surface, is flat. The acceleration sensor is mounted on the lower surface of the drip-receiving section 2. Therefore, the impact transmitted to the acceleration sensor is detected more appropriately, the three-axis acceleration of the raindrop is obtained with high accuracy, and the raindrop impact force is measured with high accuracy. 【0050】 Furthermore, multiple raindrop impact detectors 1 are provided. Therefore, the raindrop impact meter M measures the raindrop impact force over a much wider area compared to when raindrops are received by a single raindrop impact detector 1. 【0051】 Furthermore, the control unit synthesizes the combined acceleration using the acceleration of each axis whose absolute value is above the threshold. Therefore, the acceleration of each axis whose absolute value is below the threshold is ignored and not used in the synthesis of the combined acceleration. Consequently, only the extremely small raindrops that are not very useful for analysis are excluded, the usefulness of measuring raindrop impact force is not greatly impaired, and the raindrop impact force is measured in an effective state with reduced information processing load. Furthermore, the control unit obtains the raindrop impact force based on the maximum of a series of combined accelerations. The series of combined accelerations may be a collection of accelerations obtained from each axis before the threshold is exceeded n times consecutively, a sequence of combined accelerations determined by fitting a raindrop impact force damping model, or a collection of accelerations obtained from each axis of the raindrop within a predetermined time or until the next large acceleration occurs, for a collision position within a predetermined range. In this case, the raindrop impact force is measured with good accuracy and processing efficiency based on the characteristics of the raindrop. Furthermore, the control unit is included in a computer that can communicate directly or indirectly with the raindrop impact detector 1. Therefore, a control unit capable of performing the above-described processing can be constructed simply and inexpensively. 【0052】 [Second form] Next, a second embodiment of the raindrop shock meter, which is similar to the first embodiment of the raindrop shock meter M except for the raindrop shock detector, will be described. Components and parts in the second embodiment that are the same as those in the first embodiment will be appropriately denoted by the same reference numerals, and their descriptions will be omitted. Furthermore, the various modifications described above relating to the first form may be applied as appropriate in the second form. In addition, parts or all of the first form and parts or all of the second form may be combined as appropriate. 【0053】 Figure 9 is a perspective view of the raindrop impact detector 101 in the second embodiment of the raindrop impact meter, showing the top, rear, and right side views. Figure 10 is a perspective view of the raindrop impact detector 101, showing the bottom, front, and left side views. The raindrop impact detector 101 includes a drip receiving section 2, a sensor section 4, and an installation section 106. 【0054】 The mounting section 106 is cylindrical and extends vertically. The mounting section 106 is fixed to the lower surface of the drip receiving section 2 and surrounds the sensor section 4 attached to the sensor mounting section 10. The mounting section 106 has a plurality (two) of holes 108. Each hole 108 extends in the front-to-back direction. A pair of holes 108 are arranged front-to-back so as to face each other. However, the configuration of each hole 108 is not limited to the above. For example, all holes 108 may be omitted. Alternatively, the arrangement of the holes 108 may be other than front-to-back. Furthermore, the number of holes 108 may be one or three or more. The raindrop impact detector 101 is installed at the measurement point via the installation part 106. For example, a member having at least one of a groove and a hole is placed at the measurement point below the frame FR of the transmission tower, and the installation part 106 is inserted into at least one of the groove and hole of the member, thereby fixing the installation part 106 to the member. The member may be one or more pipes, a mat, a box, or an appropriate combination thereof. The pipes may be fixed to the transmission tower, or more specifically, they may be stretched between the columns of the transmission tower below the frame FR. In addition, when fixing the installation part 106 to the member, at least one of the two holes 108 may be used, for example, by passing a screw that is fixed to the member through each hole 108. 【0055】 The raindrop impact detector 101 also detects the x, y, and z accelerations necessary to obtain the impact force of the raindrops. Furthermore, the raindrop impact detector 101 can be installed at the measurement point in a different manner from the raindrop impact detector 1 of the first embodiment, by means of an installation part 106 that is different from the leg part 6. In particular, when multiple raindrop impact detectors 101 are fixed to a series of members, the multiple raindrop impact detectors 101 are connected by the series of members, so their relative positions are maintained even more closely than with the raindrop impact detector 1. 【0056】 [Third form] Next, a third form of raindrop shock meter M3 will be described, which is similar to the second form of raindrop shock meter except for the raindrop shock detector. Components and parts in the third form that are the same as those in the second form will be appropriately denoted by the same reference numerals, and their descriptions will be omitted. Furthermore, in the third form, the various modifications described above relating to the first and second forms may be applied as appropriate. In addition, at least one of the following may be combined as appropriate: part or all of the first form, part or all of the second form, and part or all of the third form. 【0057】 Figure 11 is a top, rear, and right-side perspective view of the raindrop impact detector 201 in the third embodiment of the raindrop impact meter M3. Figure 12 is a bottom, front, and left-side perspective view of the raindrop impact detector 201. Figure 13 is a schematic top view of the raindrop impact meter M3 including multiple raindrop impact detectors 201. The raindrop impact detector 201 includes a drip receiving section 202, a sensor section 4, and an installation section 106. 【0058】 The drip receiving section 202 is the same as the drip receiving section 2 of the first and second forms, except for its external shape when viewed from above and below. The external shape of the drip receiving section 202 is a regular hexagon. The raindrop impact detector 201 also detects the x, y, and z accelerations necessary to obtain the impact force of the raindrops. The raindrop impact detector 201 is installed at the measurement point via the drip receiving section 202. When multiple raindrop impact detectors 201 are installed, as shown in Figure 13, if the outer shape of each drip receiving section 202 is a regular hexagon, the gaps between adjacent drip receiving sections 202 can be filled. Therefore, the raindrop impact meter M3 can grasp the raindrop situation at the measurement point with even greater accuracy. 【0059】 [Fourth form] In a fourth embodiment of this disclosure, the raindrop impact meter M of the first embodiment is used as a falling object impact meter for falling objects other than raindrops, and the impact of falling objects other than raindrops is measured. Components and parts in the fourth embodiment that are the same as those in the first embodiment are appropriately denoted by the same reference numerals, and their descriptions are omitted. Furthermore, in the fourth form, the various modifications described above relating to at least one of the first to third forms may be applied as appropriate. In addition, at least one of the following may be combined as appropriate: part or all of the first form, part or all of the second form, part or all of the third form, or part or all of the fourth form. 【0060】 The following five types of objects were used as falling objects in the fourth form: The first object used was a stainless steel screw. This screw had a mass of 2.49 g and a length of 38 mm. As a second object, a spherical glass bead was used. This bead had a mass of 0.51 g and a diameter of 6 mm. As a third object, a frustoconical cap (No. 2) made of silicone resin was used. This cap had a mass of 4.86 g and a length of 24 mm. As the fourth object, an ellipsoidal stone was used. This stone had a mass of 0.96 g, a length of 10 mm, and a width of 8 mm. As the fifth object, a small resin cap was used, having a cylindrical body and a small cylindrical projection that protruded outward from the center of one of the planes of the body. The mass of this small cap was 0.43 g, the diameter of the body was 10 mm, the length of the body was 8 mm, and the diameter and length of the projection were both 3 mm. Furthermore, falling objects are not limited to these items and may also include, for example, hail, sand, fruit, structures, parts of structures, flying objects, and parts of flying objects. Structures may include, for example, transmission towers, buildings, and trees. Flying objects may include, for example, airplanes, aircraft, drones, rockets, missiles, bullets, satellites, arrows, and birds. 【0061】 Each falling object fell naturally without initial velocity from 40 cm above the center of the receiving section 2, which was used as the receiving part of the raindrop impact detector 1, which was used as a falling object impact detector for falling objects other than raindrops. The impact force from the falling object that struck the drip receiving section 2 in such a free fall is the combined acceleration A s Measured by (G). 【0062】 Figure 14 shows the combined acceleration A when various falling objects cause impact in the fourth form. s This graph shows an example of the change in (G). As shown in Figure 14, it can be said that the impact force was measured in a manner appropriate to the properties of each type of falling object. That is, the initial combined acceleration A 1.2 milliseconds after the start of free fall. s Therefore, the combined acceleration A of screws (made of stainless steel), stones, and beads (made of glass) is calculated based on their higher hardness and smaller contact area during impact. s The combined acceleration A of a cap (made of silicone resin) and a small cap (made of resin) that is larger, has lower hardness, and has a larger contact area during impact. s It was small. Also, the mass was largest in the order of screw, stone, and bead, and the initial combined acceleration A s The mass was large. Furthermore, the mass was larger in the order of cap, then small cap, and the initial combined acceleration A s That was a big factor. On the other hand, the resultant acceleration A s For the transition, the combined acceleration A of the screw, stone, and bead s This is the initial combined acceleration A s In contrast, it decreased rapidly over time, becoming almost zero after about 5 milliseconds. Also, the combined acceleration A of the cap s This is the initial combined acceleration A s After initially decreasing, the initial composite acceleration A occurs over a period of approximately 4 to 7 milliseconds. s It recovered to some extent, then decreased again, and the initial combined acceleration A was reached in about 10 milliseconds. s It recovered to that extent once again. Furthermore, the combined acceleration A of the small cap sThis is the initial combined acceleration A s It initially increased, then began to decrease, becoming almost zero in about 5 milliseconds. 【0063】 The fourth form of the falling object impact meter has the same configuration as the first form of the raindrop impact meter M and is capable of measuring the impact caused by the collision of falling objects. In other words, the fourth embodiment of the falling object impact meter comprises a raindrop impact detector 1 as a falling object impact detector having a sensor unit 4 including a three-axis acceleration sensor, and a control unit of a second computer 32 that obtains the falling object impact force based on the combined acceleration obtained by combining the accelerations of each axis. Thus, a falling object impact meter for measuring the impact force of a falling object is provided. Furthermore, the drip receiving section 2 in the raindrop impact detector 1, which functions as a falling object impact detector, also functions as a receiving section for falling objects. 【0064】 Furthermore, the fourth form of the falling object impact meter can also be used as an impact meter to measure the impact force applied to other objects. For example, if a falling object impact meter is used as an impact meter for projectiles, and a falling object impact detector is used as an impact detector for projectiles, the impact meter can measure the impact force generated when a projectile thrown at the impact detector collides with the receiving part, in the same way as the impact force caused by a falling object. Projectiles can be, for example, balls or spears. Furthermore, when a falling object impact meter is used as an impact meter for a moving object, and a falling object impact detector is used as an impact detector for a moving object, the impact meter can measure the impact force generated when the moving object collides with the receiving part of the impact detector, in the same way as the impact force caused by a falling object. Examples of moving objects include a moving vehicle and a flying object. [Explanation of Symbols] 【0065】 M, M3...Raindrop impact meter (impact meter, falling object impact meter) 1, 101, 201... Raindrop impact detector (impact detector, falling object impact detector) 2.Droplet receiving part (receiving part) 4. Sensor unit (accelerometer) 6 Legs 30. First Computer 32. Second Computer 106...Installation part

Claims

[Claim 1] One or more impact detectors having a 3-axis acceleration sensor, A control unit that obtains impact force based on the combined acceleration obtained by combining the accelerations of each axis, It is equipped with A shock meter characterized by the following features. [Claim 2] The impact detector has a receiving part that receives the impacting object, The first surface of the receiving portion is rounded and convex outward. The shock meter according to feature 1. [Claim 3] The second surface in the receiving portion that faces the first surface is a flat surface. The acceleration sensor is mounted on the second surface. The shock meter according to feature 2. [Claim 4] Multiple impact detectors are provided. The shock meter according to feature 1. [Claim 5] Each of the impact detectors has a receiving part that receives the impacting object. The outer shape of each of the aforementioned receiving parts is a regular hexagon. The shock meter according to feature 4. [Claim 6] Each of the aforementioned impact detectors is fixed to a series of members. The shock meter according to feature 4. [Claim 7] The control unit synthesizes the combined acceleration using the acceleration of each axis whose absolute value is greater than or equal to a threshold. The shock meter according to feature 1. [Claim 8] The control unit obtains the impact force based on the maximum of the series of combined accelerations. The shock meter according to feature 1. [Claim 9] The control unit is included in a computer that can communicate directly or indirectly with the impact detector. The shock meter according to feature 1. [Claim 10] In the shock meter according to any one of claims 1 to 9, The aforementioned impact detector is a falling object impact detector, The aforementioned impact force is the impact force of a falling object. A falling object impact meter characterized by the following: [Claim 11] In the falling object impact meter according to claim 10, The aforementioned falling object impact detector is a raindrop impact detector, The aforementioned impact force of the falling object is the impact force of the raindrop. A raindrop shock meter characterized by the following features. [Claim 12] In the shock meter according to claim 2 or claim 5, The aforementioned impacting object is a raindrop. The aforementioned impact detector is a raindrop impact detector, The aforementioned impact force is a raindrop impact force, The receiving part is a drip receiving part. A raindrop shock meter characterized by the following features.

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