Object measurement device and object measurement method

Abstract

The problem lies in providing a target measurement device and a target measurement method that can more accurately estimate the size and / or weight of a target. The solution lies in that the target measurement device (1) includes: a transceiver (10) that transmits a transmission wave into water and receives its reflected wave; a target echo signal extraction unit (32) that extracts the echo signal of the target from the received signal of the reflected wave; a peak detection unit (33) that respectively detects a plurality of peaks included in the echo signal; an intensity difference calculation unit (35) that calculates the intensity difference between the intensity of a first peak among the plurality of peaks and the intensity of a second peak different from the first peak; and a target measurement unit (37) that obtains data related to the size and / or weight of the target based on the intensity difference.

Description

Technical Field

[0001] The present invention relates to a target measurement device and a target measurement method for transmitting a transmission wave into water and measuring a target based on a reflected wave thereof. Background Art

[0002] Conventionally, a target measurement device for transmitting a transmission wave into water and measuring a target based on a reflected wave thereof has been known. For example, the body length of fish in a fish tank is measured using sound waves. A sound wave is transmitted into water from a transceiver. The reflected wave of the sound wave is received by the transceiver, and based on the received wave signal, the target strength of the fish is measured. Based on the relational expression between the target strength and the body length, the size of the fish is estimated. Such a target measurement device is disclosed in Patent Document 1.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: U.S. Patent Application Publication No. 2006 / 0018197 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] The size of a fish can vary greatly not only according to its body length but also according to its obesity. Even fish with the same body length can have significantly different sizes and weights depending on their obesity. Therefore, when estimating the size of a fish based on the relational expression between the target strength and the body length as described above, the estimation result may include an error.

[0008] In view of this problem, an object of the present invention is to provide a target measurement device and a target measurement method capable of more accurately estimating the size and / or weight of a target.

[0009] Means for Solving the Problems

[0010] A first aspect of the present invention relates to a target measurement device. The target measurement device according to this aspect includes: a transceiver that transmits a transmission wave into water and receives a reflected wave of the transmission wave; a target echo signal extraction unit that extracts an echo signal of a target from a received signal of the reflected wave; a peak detection unit that detects a plurality of peaks included in the echo signal; an intensity difference calculation unit that calculates an intensity difference between an intensity of a first peak among the plurality of peaks and an intensity of a second peak different from the first peak; and a target measurement unit that obtains data related to the size and / or weight of the target based on the intensity difference.

[0011] Here, the intensity difference calculation unit may be configured to: determine a highest peak having the highest intensity among the plurality of peaks included in the echo signal, and calculate the intensity difference using the highest peak as the first peak.

[0012] In addition, the object measurement device may be configured to further include: a time difference calculation unit that calculates a time difference between the times at which the first peak and the second peak appear; and the object measurement unit obtains the data related to the size and / or weight of the object based on the time difference.

[0013] A second aspect of the present invention relates to an object measurement method. The object measurement method according to this aspect sends a transmission wave into water, receives a reflected wave of the transmission wave, extracts an echo signal of the object from the received signal of the reflected wave, separately detects a plurality of peaks included in the echo signal, calculates an intensity difference between the intensity of the first peak and the intensity of a second peak different from the first peak among the plurality of peaks, and obtains data related to the size and / or weight of the object based on the intensity difference.

[0014] According to the above aspect, data related to the size and / or weight of the object is obtained based on the difference in intensity between the first peak and the second peak. As shown in the following embodiments, the intensity difference depends on the ratio of the body width to the body length of the object. That is, the intensity difference can be an index representing the obesity of the object. Therefore, according to the above aspect, the size and / or weight of the object can be estimated more accurately.

[0015] Advantages of the Invention

[0016] As described above, according to the present invention, an object measurement device and an object measurement method capable of more accurately estimating the size and / or weight of an object can be provided.

[0017] The advantages and significance of the present invention will become clearer through the description of the embodiments shown below. However, the embodiments shown below are merely examples when implementing the present invention, and the present invention is not limited at all to the forms described in the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a perspective view showing a usage mode of the object measurement device according to the embodiment.

[0019] Figure 2 is a block diagram showing the configuration of the object measurement device 1 according to the embodiment.

[0020] Figure 3 is a diagram showing an example of an echo signal according to the embodiment.

[0021] Figure 4 In (a), it is a diagram schematically showing the state of the reflected wave when the transmission wave according to the embodiment is reflected by the swim bladder of a fish. Figure 4 In (b), it is a diagram schematically showing the state of the reflected wave when the transmission wave according to the embodiment is reflected by the backbone of a fish.Figure 4 Figure (c) is a diagram schematically showing the state of a reflected wave when the transmitted wave involved in the embodiment is reflected by the belly of a fish. Figure 4 Figure (d) is a diagram showing the parameters used in calculating the body width of a fish in the embodiment.

[0022] Figure 5 is a diagram showing an example of a two-dimensional histogram with intensity difference and time difference as two axes in the embodiment.

[0023] Figure 6 is a diagram showing an example of a two-dimensional histogram with intensity difference and time difference as two axes in the embodiment.

[0024] Figure 7 is a diagram showing an example of a two-dimensional histogram with intensity difference and time difference as two axes in the embodiment.

[0025] Figure 8 is a diagram showing an example of a two-dimensional histogram with intensity difference and time difference as two axes in the embodiment.

[0026] Figure 9 is a flowchart showing the processing in the target measurement device in the embodiment.

[0027] Figure 10 Figure (a) is a graph showing the change in relative position obtained on each measurement day in the verification example of the embodiment. Figure 10 Figure (b) is a graph showing the change in relative level obtained on each measurement day in the verification example of the embodiment. Figure 10 Figure (c) is a graph showing the number of second peaks of the reflected wave based on the back obtained on each measurement day in the verification example of the embodiment. Detailed Embodiment

[0028] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following embodiments, an example in which the present invention is applied to a target measurement device provided in a fish tank is shown. However, the present invention is not limited to the following embodiments at all.

[0029] Figure 1 is a perspective view showing the usage mode of the target measurement device 1.

[0030] As Figure 1 shown, in the present embodiment, in a fish tank 2 provided in the sea for culturing fish as a kind of aquatic organism, the target measurement device 1 is used. The fish tank 2 includes a frame 3, a floating body 4, a net 5, and a pier 6.

[0031] The frame 3 is formed in a ring shape when viewed from above. A plurality of floating bodies 4 are installed on the frame 3. Due to the buoyancy of the floating bodies 4, the frame 3 floats on the water surface. The frame 3 is connected to a heavy object at the bottom of the water by a mooring rope (not shown).

[0032] The upper end portion of the net 5 is fixed to the frame 3. The net 5 is suspended from the frame 3 in such a way as to divide the water to form an enclosed space. Fish are raised inside this enclosed space. Above the frame 3, a pier 6 for performing various operations during aquaculture is fixed.

[0033] A float 7 floats at approximately the central portion inside the frame 3. The float 7 is connected to the pier 6 by a rope. A target measurement device 1 is arranged on this float 7.

[0034] Figure 2 It is a block diagram showing the configuration of the target measurement device 1.

[0035] The target measurement device 1 includes a transceiver 10, a transceiver 20, a signal processing unit 30, and an operation unit 40. In addition, the transceiver 10, the transceiver 20, and the signal processing unit 30 are shown in Figure 1 while the operation unit 40 is omitted. The operation unit 40 is used for performing operation input on the target measurement device 1. Electric power is supplied to each part of Figure 2 from a power supply unit (not shown). The power supply unit includes, for example, a rechargeable secondary battery such as a lithium-ion battery.

[0036] The transceiver 10 includes an element capable of converting an electrical signal and an ultrasonic vibration with each other. The transceiver 10 uses an ultrasonic transmission wave to detect the water. As Figure 1 shown, the transceiver 10 is installed at the center of the lower surface of the float 7. The transceiver 10 is arranged vertically downward and sends ultrasonic waves (transmission waves) downward from near the water surface into the water.

[0037] The transceiver 10 includes a transmitter 11 and a receiver 12. The receiver 12 has a plurality of elements divided into 4 receiving channels. The transmitter 11 sends a pulsed transmission wave into the water. In order to improve the resolution in the depth direction, it is preferable to send the transmission wave with as short a pulse as possible. Each receiving channel of the receiver 12 receives the reflected wave reflected from a target in the water. The transceiver 10 sends an electrical signal based on the received reflected wave to the transceiver 20.

[0038] Here, the transceiver 10 obtains the position of the target based on the time difference of the reflected waves received by the 4 receiving channels, that is, the phase difference of the received reflected waves. Thereby, 3D detection based on a known beam splitting method is achieved. In addition, the structure of the transceiver 10 can be appropriately changed. For example, the transceiver 10 can also be configured to perform both transmission and reception through the elements of the receiver 12.

[0039] The transceiver 20 is connected to the transceiver 10 via an electrical cable. The transceiver 20 outputs an electrical signal to the transceiver 10 via the electrical cable, which causes the transceiver 10 to transmit a transmission wave. Furthermore, the transceiver 20 receives an electrical signal received by the transceiver 10 based on the reflected wave via the electrical cable. The transceiver 20 then converts the electrical signal received from the transceiver 10 into a digital received signal and transmits it to the signal processing unit 30. The transceiver 20 converts the electrical signals received via the four reception channels into received signals and transmits them to the signal processing unit 30.

[0040] The signal processing unit 30 is configured as a well-known computer. It is connected to the transceiver 20 via a communication cable. The signal processing unit 30 communicates with the transceiver 20 via the communication cable. Through this communication, the signal processing unit 30 acquires a received signal from the transceiver 20. The signal processing unit 30 processes the received signal for target object measurement.

[0041] The signal processing unit 30 includes a transmission control unit 31 , a target object echo signal extraction unit 32 , a peak detection unit 33 , a peak arrival direction calculation unit 34 , an intensity difference calculation unit 35 , a time difference calculation unit 36 , a target object measurement unit 37 , and a storage control unit 38 .

[0042] The signal processing unit 30 includes a CPU (Central Processing Unit) and other arithmetic processing circuits, as well as a ROM (Read Only Memory), RAM (Random Access Memory), a hard disk and other storage media. The storage medium stores a program for implementing the processing for object measurement. The signal processing unit 30 executes the program. Figure 2 The functions of each part are shown in FIG. Figure 2 1 and 2 show functional modules executed by the signal processing unit 30 based on a program.

[0043] The transmission control unit 31 controls the transmitter 11 to output a transmission wave via the transceiver 20. The target object echo signal extraction unit 32 extracts the echo signal based on the reflected wave from the fish from the received signal acquired from the transceiver 20. Specifically, the target object echo signal extraction unit 32 generates a summed signal by adding the received signals based on the reflected waves received by the four receiving channels of the receiver 12. The summed signal is then envelope-detected to generate an echo signal. The target object echo signal extraction unit 32 then extracts echo signals above a predetermined threshold as echo signals based on the reflected wave from the fish.

[0044] Figure 3 is a diagram showing an example of an echo signal.Figure 3 In order to easily understand the reflection position of the waveform, the horizontal axis is converted to water depth. Here, the water depth is obtained by multiplying the time from the transmission wave to the reception of the reflected wave by the speed of sound in water and dividing it by 2. Figure 3 The vertical axis represents the target intensity based on the echo signal. Target intensity is a parameter that indicates the extent to which a portion of the reflected wave, scattered by the ultrasonic wave (transmitted wave) upon reaching the target object, returns in the direction of incidence. It is essentially equivalent to the intensity of the echo signal. Target intensity is expressed in decibels.

[0045] return Figure 2 The target echo signal extraction unit 32 extracts the target intensity value as Figure 3 Echo signals above the predetermined threshold value Th1 are considered fish echo signals. To exclude reflected waves from the net 5 and other sources, echo signals within a range where the time between transmission and reception is excessively long are excluded from the fish echo signal extraction target. For example, the water depth range of 1 to 4 meters is set as the fish echo signal extraction range. The target object echo signal extraction unit 32 outputs the echo signals based on the reflected waves from the fish to the peak detection unit 33.

[0046] The peak detection unit 33 detects peaks contained in the echo signal from the fish extracted by the target object echo signal extraction unit 32. Generally, in the echo signal from one fish, a curve showing the temporal transition of the signal level is shown, for example, Figure 3 As shown in FIG. 1 , the peak detection unit 33 detects each of the multiple peaks included in the fish echo signal. The peak detection unit 33 outputs data related to each detected peak to the peak arrival direction calculation unit 34.

[0047] The peak arrival direction calculation unit 34 calculates the arrival direction of each of the multiple peaks detected by the peak detection unit 33 based on the time difference (phase difference) between the reception times of the reflected waves on each reception channel. The arrival direction calculation is performed using the aforementioned beam splitting method. The peak arrival direction calculation unit 34 outputs the calculated arrival direction of each peak to the intensity difference calculation unit 35 and the time difference calculation unit 36, respectively.

[0048] The intensity difference calculation unit 35 and the time difference calculation unit 36 extract peaks generated from the same fish based on the arrival directions of the peaks input from the peak arrival direction calculation unit 34. Peak extraction is performed by the following method.

[0049] Generally speaking, it is known that the transmission wave (ultrasound) transmitted from the transceiver 10 is reflected most strongly by the swim bladder among various parts of the fish (such as the back and abdomen). Figure 3Among them, the peak P11 with the highest signal intensity among the multiple peaks P11, P21 to P23 included in the echo signal of the fish can be assumed to originate from the reflected wave reflected by the swim bladder. Here, this peak P11 is set as the first peak P1.

[0050] Other peaks that appear at a time near the first peak P1, that is, peaks among the remaining peaks included in the echo signal of the fish with an arrival direction substantially the same as that of the first peak P1, can be assumed to be peaks obtained from parts such as the back and abdomen of the same fish from which the first peak P1 was obtained. That is, when the difference between the arrival direction of the first peak P1 and the arrival direction of other peaks is smaller than a specified threshold, these other peaks can be assumed to be peaks obtained from parts such as the back and abdomen of the same fish from which the first peak P1 was obtained.

[0051] Based on the above assumption, the intensity difference calculation unit 35 and the time difference calculation unit 36 extract other peaks with a difference in arrival direction from the first peak P1 smaller than a specified threshold as the second peak P2 based on the arrival direction of each peak input from the peak arrival direction calculation unit 34. The intensity difference calculation unit 35 and the time difference calculation unit 36 use the first peak P1 and the second peak P2 extracted in this way as peaks originating from the same fish for the calculation process of the intensity difference and the time difference.

[0052] In Figure 3 the example, when the difference in the arrival direction between the peaks P21 to P23 and the arrival direction of the first peak P1 is smaller than a specified threshold, these peaks P21 to P23 are extracted as the second peak P2. In this case, the peaks P21 and P22 are closer (earlier reception time) than the peak P11, so they are assumed to be peaks based on the reflected wave from the dorsal fin, back, etc. of the fish. In addition, the peak P23 is farther (later reception time) than the peak P11, so it is assumed to be a peak based on the reflected wave from the abdomen, etc. of the fish.

[0053] The intensity difference calculation unit 35 calculates the intensity difference between the first peak P1 and the second peak P2 extracted by the above method, and sends the calculated intensity difference to the target measurement unit 37. For example, in Figure 3 the example, the intensity difference calculation unit 35 calculates the intensity difference L1 between the peak P11 (the first peak P1) and the peak P21 (the second peak P2), the intensity difference L2 between the peak P11 (the first peak P1) and the peak P22 (the second peak P2), and the intensity difference L3 between the peak P11 (the first peak P1) and the peak P23 (the second peak P2), and sends the calculated intensity differences L1 to L3 to the target measurement unit 37.

[0054] The time difference calculation unit 36 calculates the time difference between the first peak P1 and the second peak P2 extracted by the above method, and sends the calculated time difference to the target measurement unit 37. For example, in Figure 3In the example of [], the time difference calculation unit 36 calculates the time difference T1 between the peak P11 (the first peak P1) and the peak P21 (the second peak P2), the time difference T2 between the peak P11 (the first peak P1) and the peak P22 (the second peak P2), and the time difference T3 between the peak P11 (the first peak P1) and the peak P23 (the second peak P2), and sends the calculated time differences T1 to T3 to the target measurement unit 37.

[0055] Based on the intensity difference between the first peak P1 and the second peak P2 input from the intensity difference calculation unit 35 and the time difference between the first peak P1 and the second peak P2 input from the time difference calculation unit 36, the target measurement unit 37 obtains data related to the size and / or weight of the fish. Specifically, the target measurement unit 37 obtains data related to the body height of the fish based on the time difference, and obtains data related to the weight of the fish based on the obtained data related to the body height and the intensity difference. Hereinafter, the method of obtaining these data will be described.

[0056] Figure 4 of (a) to Figure 4 of (c) is a graph showing the relationship between the time difference between the first peak P1 and the second peak P2 and the body height of the fish.

[0057] Figure 4 of (a) shows the state of the reflected wave R1 when the transmitted wave (ultrasonic wave) is reflected by the swim bladder of the fish. Figure 4 of (b) and (c) show the states of the reflected waves R2 and R3 when the transmitted wave (ultrasonic wave) is reflected by the back and abdomen of the fish, respectively. As described above, it is known that the transmitted wave (ultrasonic wave) transmitted from the transceiver 10 has the strongest reflection for the swim bladder among each part (each part such as the back and abdomen) of the fish. Therefore, the peak of the echo signal based on the reflected wave R1 corresponds to the first peak P1 described above, and the peaks of the echo signals based on the reflected waves R2 and R3 correspond to the second peak P2 described above, respectively.

[0058] Here, the time difference between the second peak P2 and the first peak P1 based on the reflected wave from the back of the fish is as shown in Figure 4 of (b), and corresponds to the distance Ha from the swim bladder to the back. That is, by multiplying this time difference by the speed of sound in the fish body and dividing by 2, the distance Ha can be calculated. In addition, the time difference between the second peak P2 and the first peak P1 based on the reflected wave from the abdomen of the fish is as shown in Figure 4 of (c), and corresponds to the distance Hb from the swim bladder to the abdomen. That is, by multiplying this time difference by the speed of sound in the fish body and dividing by 2, the distance Hb can be calculated.

[0059] Therefore, the body height of the fish can be calculated based on the time difference between the second peak P2 based on the reflected wave R2 from the back or the reflected wave R3 from the abdomen and the first peak P1 based on the reflected wave from the swim bladder. For example, the body height of the fish can be calculated by applying the time difference between the second peak P2 based on the reflected wave R2 from the back of the fish and the first peak P1 based on the reflected wave from the swim bladder to a prescribed relationship (a relationship that takes into account the speed of sound in the body of the fish and the relationship between the distance Ha and the body height). Here, the second peak P2 based on the reflected wave R2 from the back of the fish corresponds to the second peak P2 that appears earliest among the peaks of the echo signal above the threshold value Th1 (at Figure 3 Therefore, the time difference between the second peak P2 and the first peak (in Figure 3 The time difference T2) is used to calculate the body height.

[0060] Furthermore, if the body height is H (unit: cm), the weight W (unit: g) of the fish can be expressed by the following relational expression, for example.

[0061] W=a×H b ……(1)

[0062] By taking the logarithm of both sides of equation (1), the following relationship holds.

[0063] logW=loga+b×logH……(2)

[0064] Therefore, by taking the logarithm of both weight W and height H and calculating the regression line, the coefficients a and b can be found from the intercept and slope of the regression line. By applying the found coefficients a and b to the above equation (1), the weight W of the fish can be calculated from the height H.

[0065] However, it is considered that the weight W of the fish is affected not only by the body height H but also by the body width D. Therefore, by using the body width D (unit: cm), the above formula (1) can be corrected as follows.

[0066] W=a×H b ×D c ……(3)

[0067] However, the body width D cannot be directly calculated from the fish's echo signal.

[0068] Therefore, the inventors studied the use of the intensity difference between the first peak P1 and the second peak P2 to calculate the body width D of the fish. The second peak P2 can be calculated by using the peak of the echo signal based on the reflected wave from the back of the fish (in Figure 3 Peak P22 in the middle).

[0069] Figure 4Figure (d) shows the parameters used in calculating the body width D.

[0070] In Figure 4 Figure (d), Lb is the body length of the fish and Ls is the length of the swim bladder. The swim bladder grows approximately in the same proportion as the fish grows. That is, there is a proportional relationship between the body length Lb and the length Ls of the swim bladder. Therefore, the following relational expression holds.

[0071] Ls = k × Lb...(4)

[0072] By taking the logarithm of both sides of Equation (4), the following relational expression holds.

[0073] log Ls = log Lb + log k...(5)

[0074] Here, considering that the width of the swim bladder is determined by the length of the swim bladder, the reflection intensity of the swim bladder is proportional to the square (area) of the length Ls of the swim bladder. Additionally, considering that the reflection intensity of the fish body is proportional to the product of the body length Lb and the body width D (the area of the fish body). Therefore, if the peak intensity of the reflected wave from the swim bladder is set as Ts(P1) and the peak intensity of the reflected wave from the back is set as Ts(P2), the following relational expressions hold.

[0075] Ts(P1) = ks × Ls 2 ...(6)

[0076] Ts(P2) = kb × Lb × D...(7)

[0077] By taking the logarithm of both sides of Equations (6) and (7) and converting to decibels, the following relational expressions hold.

[0078] TS(P1) = 20 log Ls + 10 log ks...(8)

[0079] TS(P2) = 10 log Lb + 10 log D + 10 log kb...(9)

[0080] In the above Equations (8) and (9), when converting the left sides of Equations (6) and (7) to decibels, TS(P1) and TS(P2) are replaced by the following expressions.

[0081] TS(P1) = 10 log Ts(P1)...(10)

[0082] TS(P2) = 10 log Ts(P2)...(11)

[0083] TS(P1) corresponds to the intensity of the above-mentioned first peak P1 (the peak of the echo signal based on the swim bladder), and TS(P2) corresponds to the intensity of the above-mentioned second peak P2 (the peak of the echo signal based on the back).

[0084] Here, if the difference between the calculation formulas (10) and (11) is calculated, the following relational expression holds.

[0085] TS(P2) - TS(P1) = 10logLb + 10logD - 20logLs + TScmb - TScms……(12)

[0086] Among them, TScmb and TScms are expressed by the following formulas.

[0087] TScmb = 10logkb……(13)

[0088] TScms = 10logks……(14)

[0089] If formula (5) is applied to the above formula (12), the following relational expression is obtained.

[0090] TS(P2) - TS(P1) = -10logLb + 10logD + α = 10log(D / Lb) + α……(15)

[0091] Among them, the constant α is expressed by the following formula.

[0092] α = TScmb - TScms - 20logk……(16)

[0093] According to the relational expression (15), it can be known that the intensity difference between the first peak P1 and the second peak P2 depends on the body width D and body length Lb of the fish. That is, considering that the intensity difference between the first peak P1 and the second peak P2 becomes an index representing the fatness of the fish. By using the relational expression (15), the body width D of the fish can be calculated based on the intensity difference between the first peak P1 and the second peak P2. In this way, the body width D of the above relational expression (3) can be obtained.

[0094] Here, if the body length Lb and body height H are in a proportional relationship, the relational expression (3) is deformed into the following formula.

[0095] W = a×H b ×Lb c ×(D / Lb) c ……(17)

[0096] Here, if the above relational expression (15) is applied to the relational expression obtained by taking the logarithm of both sides of the relational expression (17) and the coefficients and exponents are sorted out, the following formula is obtained.

[0097] logW = a' + b'logH + c'ΔTS……(18)

[0098] Here, ΔTS is the intensity difference between the first peak P1 and the second peak P2 (unit: dB).

[0099] Therefore, by performing multiple regression analysis based on logW, logH, and ΔTS to obtain coefficients a', b', and c', the weight W of the fish can be calculated by the following formula.

[0100] W = 10 a' ×H b' ×10 c'ΔTS ……(19)

[0101] In the relational expression (19), ΔTS is the intensity difference between the first peak P1 and the second peak P2, and the body height H can be calculated from the time difference between the first peak P1 and the second peak P2. Thus, based on the intensity difference calculated by the Figure 2 intensity difference calculation unit 35 and the time difference calculated by the time difference calculation unit 36, the weight W of the fish can be obtained.

[0102] In addition, in the present embodiment, instead of obtaining the weight W of each fish, the process of obtaining the average weight of the fish housed in the fish tank 2 is performed. Among them, instead of, or together with, the process of obtaining the average weight of the fish, the process of obtaining the weight W of each fish may be performed. Hereinafter, the process of obtaining the average weight of the fish will be described.

[0103] The target measurement unit 37 generates a two-dimensional histogram with the intensity difference and the time difference as two axes based on the intensity differences and time differences obtained from multiple fish. In generating the two-dimensional histogram, multiple echo signals obtained by observing the echo signal for a certain period of time (several hours to several tens of hours) are used.

[0104] Figures 5 to 8 is a diagram showing an example of a two-dimensional histogram with the intensity difference and the time difference as two axes. In Figures 5 to 8 it, the vertical axis is the intensity difference (relative level), and the horizontal axis is the time difference (relative position). Here, the time difference is converted into the relative position of the water depth at which the second peak P2 is obtained with respect to the water depth at which the first peak P1 is obtained and is defined on the horizontal axis.

[0105] Figures 5 to 8 The two-dimensional histogram of Figure 5 and Figure 6 is based on the received signal obtained by actually installing the target measurement device 1 having the above configuration in the fish tank 2. Figure 7 and Figure 8 are two-dimensional histograms obtained from yellowtail, respectively, Figure 6 and Figure 5 are two-dimensional histograms obtained from red sea bream, respectively. Figure 8 The histogram of Figure 7 is based on the data obtained in the stage where the yellowtail has grown further compared to the histogram of

[0106] The target measurement unit 37 obtains representative values of the intensity difference and the time difference, for example, between the first peak P1 based on the reflected wave reflected from the swim bladder of the fish and the second peak P2 based on the reflected wave reflected from the back of the fish, respectively, from the two-dimensional histogram. In Figures 5 to 8 , in the area enclosed by the dash-dotted line, a data group including the intensity difference and the time difference between the first peak P1 (swim bladder) and the second peak P2 (back) is included. The target measurement unit 37 sets an extraction range where these data groups may exist for the two-dimensional histogram. Here, as the extraction range, a range determined in advance for each species of fish can be used. The target measurement unit 37 obtains the intensity difference and the time difference at the position where the frequency is concentrated in the extraction range as representative values.

[0107] For example, the target measurement unit 37 sets a rectangular extraction range in the two-dimensional histogram, and applies the processing of kernel density estimation to the data group included in the extraction range for each of the vertical axis (intensity difference) and the horizontal axis (time difference). Thereby, the target measurement unit 37 obtains a smoothed frequency distribution curve for each of the vertical axis (intensity difference) and the horizontal axis (time difference) with respect to the data group included in the extraction range. Then, in each of the obtained frequency distribution curves, the target measurement unit 37 obtains the intensity difference and the time difference with the maximum frequency, and sets the obtained intensity difference and time difference as representative values of the intensity difference and the time difference corresponding to the fish group housed in the fish tank 2.

[0108] In addition, the method for obtaining the representative values is not limited to this. As long as the average intensity difference and time difference are set as the representative values, other methods can also be used. For example, the target measurement unit 37 may not apply kernel density estimation to the extraction range, but obtain the mode (intensity difference and time difference with the highest frequency) of the intensity difference and the time difference based on the data included in the extraction range, and set the obtained mode as the representative values of the intensity difference and the time difference corresponding to the fish group housed in the fish tank 2. Or, the target measurement unit 37 may calculate the centroid position of the frequency distribution in the extraction range, and set the intensity difference and the time difference corresponding to the centroid position as the representative values of the intensity difference and the time difference corresponding to the fish group housed in the fish tank 2. In addition, the average value or the median value, etc. of the intensity difference and the time difference in the extraction range can also be set as the representative values of the intensity difference and the time difference corresponding to the fish group housed in the fish tank 2.

[0109] In Figure 5 and Figure 6 In the example (yellowtail) of Figure 7 and Figure 8In the example of (red sea bream), values near -21 dB and values near -19 dB are respectively obtained as representative values of the intensity difference (relative level), and values near -0.03 m and values near -0.05 m are obtained as representative values of the time difference (relative position). These representative values all change along with the growth of the targets (yellowtail, red sea bream).

[0110] The target measurement unit 37 applies the obtained representative values of the intensity difference and the time difference to the above relational expression (19) to calculate the average weight W of the fish accommodated in the fish tank 2. In this way, the average weight W of the fish is obtained.

[0111] Figure 9 It is a flowchart showing the processing in the target measurement device 1.

[0112] If the processing starts, first, the transmission control unit 31 makes the transceiver 20 execute the transmission of the transmission wave (S11). Thereby, a pulsed transmission wave is transmitted from the transceiver 10 at a prescribed period. Corresponding to this transmission wave, the transceiver 20 generates a reception signal based on the reception wave signals input from the respective reception channels of the transceiver 10 for each period, and transmits the generated reception signal to the target echo signal extraction unit 32 (S12).

[0113] The target echo signal extraction unit 32 adds the reception signals of the respective reception channels to generate an echo signal, and extracts the echo signal in the range above the threshold Th1 as the echo signal of the fish (S13). The target echo signal extraction unit 32 transmits the extracted echo signal of the fish to the peak detection unit 33. The peak detection unit 33 detects a plurality of peaks included in the echo signal of the fish, and transmits the detection result to the peak arrival direction calculation unit 34 (S14). The peak arrival direction calculation unit 34 calculates the arrival direction of each peak based on the reception time difference (phase difference) of the four reception channels of the transceiver 10, and transmits the calculation result to the intensity difference calculation unit 35 and the time difference calculation unit 36 (S15).

[0114] The intensity difference calculation unit 35 sets the peak with the highest intensity among the plurality of peaks detected by the peak detection unit 33 as the first peak P1, and sets the peaks whose difference in arrival direction from the first peak P1 is smaller than the prescribed threshold as the second peak P2. Then, the intensity difference calculation unit 35 calculates the intensity difference between the first peak P1 and the second peak P2, and transmits the calculated intensity difference to the target measurement unit 37 (S16).

[0115] The time difference calculation unit 36 sets the first peak P1 and the second peak P2 through the same processing as the intensity difference calculation unit 35. Then, the time difference calculation unit 36 calculates the time difference between the first peak P1 and the second peak P2, and transmits the calculated time difference to the target measurement unit 37 (S17).

[0116] The target measurement unit 37 aggregates the intensity difference and the time difference input from the intensity difference calculation unit 35 and the time difference calculation unit 36, and generates a two-dimensional histogram with the intensity difference and the time difference as two axes as described above based on the aggregated intensity difference and time difference. Then, the target measurement unit 37 obtains representative values of the intensity difference and the time difference as described above based on the generated two-dimensional histogram, and applies the obtained representative values to the above relational expression (19) to calculate the average weight W of the fish accommodated in the fish tank 2 (S18). The target measurement unit 37 transmits the calculated weight W to the storage control unit 38.

[0117] The storage control unit 38 stores the received weight W in its own storage medium and also stores it in the external memory 50 that is detachably attached to the target measurement device 1 (S19). Thus, the processing in the target measurement device 1 ends. By detaching the external memory 50 from the target measurement device 1 and attaching it to an external computer or the like, the user can refer to the average weight W of the fish. Thus, the user can grasp the growth status of the fish in the fish tank 2.

[0118] <Verification Example>

[0119] The inventor actually performed the processing in the above-described embodiment on the yellowtail cultured in the fish tank and measured the average weight of the yellowtail. The data was measured four times during the period from the end of July to the end of November in 2018.

[0120] (1) First time: July 30th, 31st, August 1st

[0121] (2) Second time: October 1st, 2nd

[0122] (3) Third time: October 30th, 31st, November 1st

[0123] (4) Fourth time: November 28th, 29th, 30th

[0124] In each measurement, the actual weight of the yellowtail was also measured. The measured values (average values) are as follows.

[0125] (1) First time: 370 g

[0126] (2) Second time: 1040 g

[0127] (3) Third time: 1290 g

[0128] (4) Fourth time: 1650 g

[0129] Figure 10 (a) is a graph showing the change in the relative position (the relative position obtained by converting the time difference between the first peak P1 and the second peak P2 into the water depth difference between the two) obtained on each measurement date. In addition,Figure 10 Graph (b) shows the change in the relative level (intensity difference between the first peak P1 and the second peak P2) obtained on each measurement day. Here, as the second peak P2, the peak based on the reflected wave from the backbone of a fish (yellowtail) was used in the same manner as in the above-described embodiment.

[0130] Figure 10 Graph (c) shows the number of the second peaks P2 of the reflected wave from the backbone obtained on each measurement day. Since the measurement time is different for each measurement day, the detected number of the second peaks P2 is different. The shortest measurement time is 3.5 hours on November 28, and the longest measurement time is 24 hours on August 1.

[0131] Based on the data obtained through the above measurement, by calculating the above regression line, the coefficients a and b of the above formula (1) are obtained. At this time, the coefficient a is 2.93 and the coefficient b is 4.35. Using these values, the average weight W of the fish (yellowtail) in each measurement is obtained based on the above formula (1). At this time, the average value of the error rate of the weight W with respect to the measured value is 5.8%. In particular, if November 28 with a short measurement time and insufficient data volume is excluded, the average value of the error rate is 4.5%. Therefore, through the above formula (1), the average weight of the fish (yellowtail) was also obtained with a low error rate.

[0132] Next, based on the data obtained through the above measurement, by the above multiple regression analysis, the coefficients a', b', and c' of the above formula (19) are obtained. At this time, the coefficient a' is 1.38, the coefficient b' is 3.30, and the coefficient c' is 0.0146. Using these values, the average weight W of the fish (yellowtail) in each measurement is obtained based on the above formula (19). At this time, the average value of the error rate of the weight W with respect to the measured value is 4.9%. In particular, if November 28 with a short measurement time and insufficient data volume is excluded, the average value of the error rate is 3.4%. In this way, by using the above formula (19), the error rate of the average weight of the fish (yellowtail) can be significantly suppressed, and in addition, the error rate is greatly improved compared with the case of using the above formula (1). Thus, the effect of the above-described embodiment was confirmed.

[0133] <Effect of the Embodiment>

[0134] According to the embodiment, the following effects can be obtained.

[0135] Based on the intensity difference between the first peak P1 and the second peak P2, data related to the weight of the target object (fish) is obtained. As shown in the above relational expression (15), the intensity difference depends on the ratio of the body width D to the body length Lb of the target object (fish). That is, the intensity difference can be an index representing the fatness of the target object (fish). Therefore, by using the intensity difference between the first peak P1 and the second peak P2, the weight of the target object (fish) can be estimated more accurately.

[0136] In addition, the target object measurement unit 37 also obtains data related to the weight of the target object (fish) by using the time difference between the first peak P1 and the second peak P2. Specifically, the target object measurement unit 37 calculates the body height H of the target object (fish) based on the time difference between the first peak P1 and the second peak P2, and applies the calculated body height H and the intensity difference to the relational expression (19) to calculate the weight of the target object (fish). Thereby, data related to the weight of the target object (fish) can be obtained with high precision.

[0137] In addition, the target object measurement unit 37 obtains data related to the weight of the target object (fish) based on the histograms of the intensity differences and time differences calculated for a plurality of echo signals. More specifically, the target object measurement unit 37 obtains representative values of the intensity differences and time differences in the histograms, and based on the obtained representative values, obtains the average weight of the target object (fish). Thereby, as shown in the above verification example, the average weight of the target object (fish) with a significantly suppressed error rate can be obtained. Thereby, data related to the average weight of the target object (fish) can be obtained with high precision.

[0138] In addition, in order to obtain data related to the weight of the target object (fish) with higher precision, as shown in the above embodiment, it is preferable to obtain the intensity difference and the time difference for the second peak P2 that appears earlier in time than the first peak P1 among the plurality of peaks included in the echo signal, and obtain data related to the weight of the target object (fish).

[0139] That is, as in the above embodiment, when the transmission wave is transmitted downward, in the range later in time than the first peak P1, peaks based on the second echo or the third echo from the swim bladder may appear. Therefore, these peaks are likely to coincide with the peaks based on the reflected waves from the abdomen or the like, and it is difficult to obtain the peak based on the reflected wave from the abdomen or the like as the second peak P2 with high precision.

[0140] In contrast, in the range earlier in time than the first peak P1, there are no peaks based on the second echo or the third echo from the swim bladder. Therefore, the second peak P2 based on the reflected wave from the back or the like can be obtained with high precision. Thereby, by using the intensity difference and the time difference obtained according to the second peak P2 that appears earlier in time than the first peak P1, data related to the weight of the target object (fish) can be obtained with higher precision.

[0141] In addition, as in the above embodiment, when the transmission wave is transmitted downward, the peak of the reflected wave from the ridge is usually Figure 3 The earliest peak among the multiple peaks included in the echo signal that are above the threshold value Th1 is selected. Therefore, the earliest peak among these multiple peaks can be roughly assumed to be the peak based on the back of the target object (fish). Thus, as in the above embodiment, by setting the earliest peak as the second peak P2 used in the fish weight acquisition process, data related to the target object (fish) weight can be acquired with higher accuracy.

[0142] Furthermore, in the above-described embodiment, the peak arrival direction calculation unit 34 calculates the arrival directions of the first peak P1 and other peaks. Other peaks whose arrival directions differ from the arrival direction of the first peak P1 by less than a predetermined threshold are set as second peaks P2. Consequently, the first peak P1 and the second peak P2 originating from the same target object (fish) are used in the fish weight determination process, while peaks resulting from echoes from other fish or peaks resulting from sudden noise are excluded from the process. Consequently, data related to the target object (fish) weight can be acquired with higher accuracy.

[0143] Here, the peak arrival direction calculation unit 34 calculates the arrival direction of each peak based on the difference (phase difference) in the time it takes for the four receiving channels of the transceiver 10 to receive the reflected waves. This allows the arrival direction of each peak to be calculated smoothly and accurately based on the beam splitting method.

[0144] <Change Example>

[0145] The present invention is not limited to the above-described embodiment. In addition, various modifications can be made to the embodiment of the present invention in addition to the above-described configuration.

[0146] For example, in Figure 9 In step S18, the average weight W of the fish may not necessarily be calculated. For example, in step S18, based on the above-mentioned relationship (15), the average body width D of the fish or the ratio (D / Lb) of the average body width D to the body length Lb may be calculated as data related to the size and / or weight of the fish. Based on these data, the size and obesity of the target object (fish) can also be grasped. In this case, in step S19, the calculated average body width D or ratio (D / Lb), and the body height H of the fish calculated based on the time difference are stored in the external memory 50. When obtaining the average weight of the fish, for example, in an external computer equipped with the external memory 50, the weight can be calculated based on these data. In this case, as in the above-mentioned embodiment, the average weight of the fish can be obtained with high precision.

[0147] In addition, the processing of step S18 can also be performed by an external computer. In this case, Figure 9Step S18 is omitted from the flowchart. Additionally, in step S19, the data groups of the intensity difference and time difference calculated in steps S16 and S17 are stored in the external memory 50. Then, in an external computer with the external memory 50 installed, the data groups are read out from the external memory 50 and the same processing as in step S18 is performed. Thus, the average weight of the fish is calculated. In this case as well, similar to the above-described embodiment, the average weight W of the fish can be obtained with high precision.

[0148] Furthermore, the number of receiving channels of the transceiver 10 is not limited to 4, and 5 or more can also be set. In this case as well, the arrival direction of each peak can be calculated through processing based on the beam splitting method.

[0149] Additionally, the receiving channels of the transceiver 10 can also be 2. In this case, the transceiver 10 can be replaced with a known dual-beam type transceiver. The transceiver 10 includes a transmitting wave device 11 and a receiving wave device 12 having 2 receiving channels. The transmitting wave device 11 transmits a transmitting wave toward the water in the same manner as in the above-described embodiment. The 2 receiving channels of the receiving wave device 12 are receiving channels with different directivities, and each receives the reflected wave reflected from a target in the water. Then, the transceiver 10 converts the data related to the received reflected wave into an electrical signal.

[0150] In the case of using the dual-beam method, the peak arrival direction calculation unit 34 obtains the angle formed by the arrival direction of the reflected wave and the direction of the central axis of the transmitting wave based on the difference in echo intensity received by the 2 receiving channels. Thus, it is possible to determine whether the first peak P1 and the second peak P2 originate from the same fish.

[0151] To implement 2 receiving channels with different directivities, for example, by arranging 2 elements with different sizes in the receiving wave device 12 and having each element perform reception, 2 receiving channels can be formed. Without being limited thereto, for example, 1 element can also be used to perform reception at 2 frequencies of low frequency and high frequency to form 2 receiving channels. In addition, the structure of the transceiver 10 can be appropriately changed. For example, as the transmitting wave device 11, the elements of the receiving wave device 12 can also be used, and it can be configured to transmit and receive waves with the same elements.

[0152] Additionally, in the above-described embodiment, since the processing is performed using the echo signal (target intensity) converted into decibels, as Figure 3 shown, the intensity difference is obtained as the difference between the intensity of the first peak P1 and the intensity of the second peak P2. However, in the case of performing processing with the value (linear value) before being converted into decibels, the intensity difference can be obtained as the ratio of the intensity of the first peak P1 to the intensity of the second peak P2. In this case, by using the intensity difference as a ratio and performing the same processing as in the above-described embodiment, data related to the size and / or weight of the target (fish) can also be obtained.

[0153] In addition, the signal processing unit 30 may also generate display data for displaying data related to the size and weight of the target. In this case, the signal processing unit 30 may also output the display data to a display device connected to the signal processing unit 30.

[0154] In addition, in the above-described embodiment, data related to the weight of the target is obtained based on the intensity difference and time difference between the first peak P1 and the second peak P2. However, data related to the size of the target, such as the ratio (D / Lb) of the body width D of the target to the body height H or the body length Lb, may also be obtained. The body height H of the target is obtained based on the time difference between the first peak P1 and the second peak P2 as described in (a) to (c) of Figure 4 The ratio (D / Lb) of the body width D of the target to the body height H or the body length Lb can be obtained by applying the intensity difference between the first peak P1 and the second peak P2 to the above-described relational expression (15). In addition, the body width D of the target may also be obtained as data related to the size of the target.

[0155] In addition, in the above-described embodiment, the average weight of the fish housed in the fish tank 2 is obtained by using a two-dimensional histogram with the intensity difference and time difference as two axes. However, data related to the weight and size of each fish can also be obtained for each individual fish based on the intensity difference and time difference obtained for each fish.

[0156] In addition, in the above-described embodiment, the transceiver 10 is vertically disposed downward with the transmission wave (ultrasonic wave) being transmitted downward from the water surface side into the water. However, the transceiver 10 may also be disposed at the bottom of the net 5 and transmit the transmission wave (ultrasonic wave) vertically upward toward the water surface above. In this case, the second peak P2 based on the reflected wave from the fish's back appears later than the first peak P1, and the second peak P2 based on the reflected wave from the abdomen appears earlier than the first peak P1. In this case, it is also preferable to use the second peak P2 based on the reflected wave from the abdomen that appears earlier than the first peak P1 to avoid the influence of the second echo or third echo from the swim bladder, as the second peak P2 for obtaining the size and / or weight of the target.

[0157] In addition, in the above-described embodiment, for the sake of convenience of explanation, a two-dimensional histogram with the intensity difference and time difference as two axes is shown in Figures 5 to 8 However, it is not necessarily required to generate such a two-dimensional histogram. It is also possible to perform data processing on the data group and perform operations related to reference Figures 5 to 8The description of the processing is the same processing. For example, in the above-described embodiment, it is also possible to extract only the data group included in the extraction range (the range of intensity difference and the range of time difference) for obtaining the representative values of the intensity difference and the time difference, and apply the kernel density estimation process to the extracted data group for each of the intensity difference and the time difference to obtain the frequency distribution curve, and obtain the intensity difference and the time difference with the highest frequency in the obtained frequency distribution curve as the representative values of the intensity difference and the time difference. Alternatively, it is also possible to obtain, for each of the intensity difference and the time difference, the intensity difference and the time difference with the highest occurrence frequency for the extracted data group, and obtain the obtained intensity difference and time difference as the representative values of the intensity difference and the time difference.

[0158] In addition, it is also possible to perform the processing based on the histogram by data processing without generating the histogram as a chart. The configurations of Technical Solutions 4 and 5 are not limited to generating the histogram as a chart, but include performing the processing assuming the histogram by data processing.

[0159] In addition, as described above, the transceiver 10 preferably transmits the transmitted wave (ultrasonic wave) with as short a pulse as possible in order to improve the resolution in the depth direction. However, instead of using a short pulse, it is also possible to use a pulse called a chirp signal in which the frequency changes temporally, and apply pulse compression to the received signal.

[0160] In addition, the target object for data acquisition is not limited to the fish cultured in the farm (for example, the fish tank 2). For example, it is also possible to install the transceiver 10 on a fishing boat and measure the weight and size of a school of fish of approximately the same size and weight swimming in the sea.

[0161] In addition, the embodiments of the present invention can be appropriately modified within the scope described in the claims.

[0162] Description of reference numerals:

[0163] 1 Target object measurement device

[0164] 10 Transceiver

[0165] 32 Target object echo signal extraction unit

[0166] 33 Peak detection unit

[0167] 34 Peak arrival direction calculation unit

[0168] 35 Intensity difference calculation unit

[0169] 36 Time difference calculation unit

[0170] 37 Target object measurement unit

[0171] Terms:

[0172] Not all of the objectives or effects / advantages may be achieved in accordance with any particular embodiment described in this specification. Thus, for example, those skilled in the art can conceive that a particular embodiment can be configured to operate in a manner that achieves or optimizes one or more of the effects / advantages taught in this specification, but may not necessarily achieve other objectives or effects / advantages taught or suggested in this specification.

[0173] All of the processes described in this specification can be specifically implemented by software code modules executed by a computing system including one or more computers or processors and be fully automated. The code modules can be stored in any type of non-volatile computer-readable medium or other computer storage device. Some or all of the methods can be specifically implemented using dedicated computer hardware.

[0174] There are many other variations in addition to the ways described in this specification, which are obvious from this disclosure. For example, according to an embodiment, any particular action, event, or function of the algorithms described in this specification can be executed in a different time sequence, can be added, combined, or completely excluded (e.g., not all of the described actions or events are necessary for the execution of the algorithms). Further, in a particular embodiment, actions or events can be executed not sequentially (serially) but concurrently (in parallel) through, for example, multi-threading, interrupt handling, or multiple processors or processor cores, or on other parallel architectures. Further, different tasks or processes can also be executed by different machines and / or computing systems that can function together.

[0175] The various illustrative logical modules and units described in connection with the embodiments disclosed in this specification can be implemented or executed by a machine such as a processor. The processor can be a microprocessor, but alternatively, the processor is a controller, a microcontroller, or a state machine, or a combination thereof, etc. The processor can include an electrical circuit configured to process computer-executable instructions. In other embodiments, the processor includes an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable devices that perform logical operations without processing computer-executable instructions. The processor can also be installed as a combination of computing devices, such as a combination of a digital signal processor (digital signal processing device) and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration. In this specification, mainly digital technology is described, but the processor can also mainly include analog components. For example, part or all of the signal processing algorithms described in this specification can be installed by an analog circuit or an analog-digital hybrid circuit. The computing environment includes a computer system based on a microprocessor, a mainframe computer, a digital signal processor, a portable computing device, a device controller, or a computing engine within a device, but can include any type of computer system not limited thereto.

[0176] Unless otherwise noted, conditional words such as "can", "be able to", "may", or "have the possibility" should be understood in the context generally used to convey that "a particular embodiment includes a particular feature, element, and / or step, but other embodiments do not". Therefore, such conditional words generally do not indicate that the feature, element, and / or step is required in any way in one or more embodiments, or that one or more embodiments necessarily include the logic for determining whether these features, elements, and / or steps are included in any particular embodiment or whether they are executed.

[0177] Optional language such as the phrase "at least one of X, Y, Z" should be understood in the context generally used to indicate that an item, term, etc. can be any one of X, Y, Z or any combination thereof (e.g., X, Y, Z). Therefore, such optional words generally do not indicate that a particular embodiment requires each of at least one of X, at least one of Y, or at least one of Z to exist separately.

[0178] Any process description, element, or module in a flowchart described in this specification and / or shown in the accompanying drawings should be understood as an object potentially representing a part of a module, segment, or code, including one or more executable commands for implementing a specific logical function or element in the process. Alternative embodiments are included within the scope of the embodiments described in this specification, where elements or functions can be deleted from or executed in a different order from the illustrated or described content, substantially simultaneously or in the reverse order, as understood by those skilled in the art according to the associated functionality.

[0179] Unless otherwise explicitly stated, numerals such as "a" should generally be interpreted to mean: including one or more of the items described. Thus, statements such as "a device configured in a... manner" mean including one or more of the listed devices. Such one or more listed devices can also be collectively configured in a manner that implements the recited reference. For example, "a processor configured to perform the following A, B, and C" can include a first processor configured to perform A and a second processor configured to perform B and C. Moreover, even when specific numbers of the introduced embodiments are explicitly listed, those skilled in the art should interpret such listings to typically mean at least the listed numbers (e.g., a simple listing of "listing two" without other modifiers generally means listing at least two, or listing two or more).

[0180] Generally, terms used in this specification are generally judged by those skilled in the art to be "non-limiting" terms (e.g., a term such as "comprising..." should be interpreted as "more than that, at least comprising...", a term such as "having..." should be interpreted as "at least having...", a term such as "including" should be interpreted as "including the following, but not limited to this", etc.).

[0181] For the purpose of illustration, terms such as "horizontal" in this specification are defined regardless of its direction, as the plane of the bottom surface of the area where the illustrated system is used or a plane parallel to the surface, or the plane where the illustrated method is implemented. The term "bottom surface" can be replaced with terms such as "ground surface" or "water surface". The term "vertical" refers to a direction perpendicular / vertical to the defined horizontal line. Terms such as "upper side", "lower side", "lower", "upper", "side surface", "higher", "lower", "above", "over...", "under" are defined relative to the horizontal plane.

[0182] As used in this specification, terms such as "attached", "connected", "paired" and other related terms should be interpreted to include detachable, movable, fixed, adjustable, and / or separable connections or couplings, unless otherwise noted. Connections / couplings include direct connections and / or connections having an intermediate structure between the two described components.

[0183] Unless otherwise expressly stated, numbers following terms such as "about", "substantially" and "essentially" as used in this specification include the recited numbers, and further represent amounts that are close to the recited amounts for performing the desired function or achieving the desired result. For example, "about", "substantially" and "essentially" refer to values less than 10% of the recited value, unless otherwise expressly stated. As used in this specification, features of the embodiments disclosed after terms such as "about", "substantially" and "essentially" further represent several variable features for performing the desired function or achieving the desired result with respect to that feature.

[0184] In the above embodiments, many variations and modifications can be added, and these elements should be understood to be included in other allowable examples. All such modifications and variations are intended to be included within the scope of the present disclosure and are protected by the following claims.

Claims

1. A target measurement device, characterized in that, Comprising: A transceiver that transmits a transmission wave into water and receives the reflected wave of the transmission wave; A target echo signal extraction unit that extracts the echo signal of a target from the received signal of the reflected wave; A peak detection unit that respectively detects a plurality of peaks included in the echo signal; An intensity difference calculation unit that calculates the intensity difference between the intensity of a first peak among the plurality of peaks and the intensity of a second peak different from the first peak; and A target measurement unit that obtains data related to the size and / or weight of the target based on the intensity difference; The intensity difference calculation unit determines the highest peak having the highest intensity among the plurality of peaks included in the echo signal, and calculates the intensity difference using the highest peak as the first peak.

2. The target measurement device according to claim 1, further comprising: A time difference calculation unit that calculates the time difference between the appearance times of the first peak and the second peak; The target measurement unit obtains the data related to the size and / or weight of the target based on the time difference.

3. The target measurement device according to claim 2, wherein the target measurement unit obtains the data related to the size and / or weight of the target based on a histogram of the intensity difference and the time difference calculated for a plurality of echo signals.

4. The target measurement device according to claim 3, wherein the target measurement unit obtains representative values of the intensity difference and the time difference in the histogram, and obtains the data related to the size and / or weight of the target based on the representative values.

5. The target measurement device according to any one of claims 1 to 4, wherein the transceiver substantially transmits the transmission wave downward; the second peak is a peak that appears earlier in time than the first peak among the plurality of peaks included in the echo signal.

6. The object measurement device according to any one of claims 1 to 4, characterized in that Further comprising: A peak arrival direction calculation unit that calculates the arrival direction of each of the plurality of peaks included in the echo signal based on the reflected wave; the second peak is a peak among the plurality of peaks whose difference in arrival direction from the first peak is smaller than a specified threshold value.

7. The target measurement device according to claim 6, wherein the transceiver has four or more receiving channels for receiving the reflected wave; the peak arrival direction calculation unit calculates the arrival direction based on the time difference between the times when each of the receiving channels receives the reflected wave.

8. The target measurement device according to claim 6, wherein the transceiver has two receiving channels for receiving the reflected wave; the peak arrival direction calculation unit calculates the arrival direction based on the intensity difference between the reflected waves received by each of the receiving channels.

9. The target measurement device according to any one of claims 1 to 4, wherein the target is a fish raised in a fish farm.

10. The target measurement device according to claim 9, wherein the transceiver substantially transmits the transmission wave along the vertical direction; the target measurement unit obtains the fish body width as the data related to the size and / or weight of the target.

11. A target measurement method, characterized in that Send a transmission wave into water, Receive the reflected wave of the transmission wave, Extract the echo signal of the target from the received signal of the reflected wave, Detect each of the multiple peaks included in the echo signal respectively, Calculate the intensity difference between the intensity of the first peak among the multiple peaks and the intensity of a second peak different from the first peak, Based on the intensity difference, obtain data related to the size and / or weight of the target, When calculating the intensity difference, Determine the highest peak with the highest intensity among the multiple peaks included in the echo signal, Use the highest peak as the first peak to calculate the intensity difference.

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