Patent Description:
Background description includes information that may be useful in understanding the present disclosure. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed subject matter, or that any publication specifically or implicitly referenced is prior art.

Aquaculture is the breeding, rearing, and harvesting of fish, shellfish, plants, algae, and other organisms in all types of water environments. In aquaculture, there is need to measure fish weight without actually touching the fish. Conventionally, technology based on stereo type camera is used to measure the fish weight. In another conventional echo sounding technology, an ultrasonic detection apparatus is used to measure the fish weight. The ultrasonic detection apparatus has a transmitter and a receiver to send a transmission wave signal and receive a reception signal containing echo data after reflecting from the target object (for example fish).

With the stereo camera technology as explained in <NPL>, the two views of the fish can be obtained from captured images of the fish with two different cameras which enables to measure fish length and fish width when the cameras are looking in a vertical direction. In another configuration, when the cameras are looking in a horizontal direction, fish length and fish height can be obtained. However, as the stereo camera based technology measures fish sizes only in two dimensions, an accurate weight of the fish cannot be measured.

With the echo sounding technology as explained in <NPL>". , fish echo enables to measure fish length based on Target Strength (TS), when the transducer is sounding in a vertical direction.

Therefore, the echo sounding technology alone or the stereo camera technology alone cannot provide a measurement of all <NUM> dimensions, i.e., length, height, width of target, and therefore cannot accurately estimate target weight.

<CIT> discloses a system for determining the biomass, size and number of tuna in a region of water. A measurement means is used which comprises two cameras acting to obtain a sequence of stereoscopic images with two sub-sequences, and an acoustic sensor made up of an echo sounder and a transducer, generating an echogram. The measurement means are installed submerged in a known position and aimed in an upward direction, such that ventral measurements of the tuna passing through the region of water are taken. The echogram is used for determining the number of tuna, whereas the images are used for determining their size, and accordingly their weight. Given that the relative positions of the cameras are known, the distance at which the tuna is located can be triangulated and compensation can be made for the measurement of size considering said distance.

The document by <NPL>, discloses an experimental setup to estimate the biomass of caged bluefin tuna. A combined system of acoustic and optical techniques was used in order to obtain direct values of acoustic target strength (TS) and information on the orientation of tuna inside the acoustic beam and their size.

<CIT> discloses a fish finder which uses an acoustic transducer to detect fish. It is disclosed that fish body height can be calculated based on the length of the fish echo signal. It is disclosed that fish body length can be obtained from the echo signal. It is also disclosed that fish weight can be calculated based on body length.

To solve the above technical problem, i.e., accurately measuring weight of target, the present subject matter provides an apparatus and method for measuring length, width, and height of the target.

According to one aspect of the present invention there is provided a target measuring apparatus as defined in claim <NUM>.

According to another aspect of the present invention there is provided a method for measuring a weight of a target as defined in claim <NUM>.

Preferred features of the invention are recited in the dependent claims.

It is a general object of the present disclosure to provide an apparatus and a method for measuring weight of a target (for example fish).

It is an object of the present disclosure to provide an apparatus and a method for measuring weight of a target based on length, width, and height.

These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.

This summary is provided to introduce concepts related to an apparatus and a method for measuring weight of a target based on length, width, and height. The concepts are further described below in the detailed description.

The present disclosure relates to a target measuring apparatus. The target measuring apparatus includes a transducer configured to transmit a transmission wave into water and configured to generate a reception signal based on a reflection wave of the transmission wave on a target; and a camera configured to take a picture of the target, the camera and the transducer facing a first direction. The target measuring apparatus further includes a target measuring system coupled to the transducer and the camera. The target measuring system includes a first length measuring module configured to measure a first length of the target based on the reception signal, the first length being measured in a direction parallel with the first direction; a target distance measuring module configured to measure a target distance between the camera and the target based on the reception signal; a second and third length measuring module configured to measure a second length and a third length of the target based on the picture and the target distance, the second length being measured in a second direction, the third length being measured in a third direction perpendicular to the second direction, the second and third directions forming a plane perpendicular to the first direction; and a weight measuring module configured to measure a weight of the target based on the first length, the second length, and the third length of the target.

In an aspect, the first length measuring module measures the first length based on a measure of a duration of at least a part of the reception signal that corresponds to the target.

In an aspect, the second and third length measuring module measures the second length based on a measure of a longitudinal size of the target on the picture, and the third length based on a measure of a lateral size of the target on the picture.

In an aspect, the second and third length measuring module measures the second length and the third length based on a focal length of the camera.

In an aspect, the weight measuring module measures the weight of the target based on a model of the target, the model linking the first length, the second length, and the third length of the target with the weight of the target.

In an aspect, the first direction is vertical; the first length corresponds to a target height; the second length corresponds to a target length; and the third length corresponds to a target width.

In an aspect, the target measuring apparatus includes the target measuring system selects the target that is close to centre of the picture.

In an aspect, the target measuring system is further configured to select the target having a straight body on the picture.

In an aspect, the target measuring system selects the target that is swimming substantially perpendicular to optical axis of the camera.

In an aspect, the target is a fish to be raised in an aquaculture environment.

The present disclosure further relates to a method for measuring a weight of a target. The method includes measuring a first length of the target based on a reception signal generated by a transducer based on a reflection wave of a transmission wave transmitted on the target; measuring a target distance between a camera and the target based on the reception signal, the camera is being configured to take a picture of the target, the camera and the transducer facing a first direction parallel to a direction in which the first length is measured; measuring a second length and a third length of the target based on the picture and the target distance, the second length being measured in a second direction, the third length being measured in a third direction perpendicular to the second direction, the second and third directions forming a plane perpendicular to the first direction; and measuring a weight of the target based on the first length, the second length, and the third length of the target.

Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

The illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and methods that are consistent with the subject matter as claimed herein, wherein:.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

Various embodiments and/or implementations described herein relates to an apparatus and a method for measuring weight of a fish in an aquaculture. In an embodiment represented in <FIG>, a target measuring apparatus <NUM> (hereinafter may be referred as apparatus <NUM>) includes a camera <NUM> and a transducer <NUM> of a sounder. In an aspect and as show in <FIG>, the camera <NUM> and the transducer <NUM> are placed next to each other. The camera <NUM> and transducer <NUM> of the sounder are positioned at the same level in a vertical direction and are facing vertically downward from above the target <NUM>. However, without deviating from the scope of the present disclosure, those skilled in the art can appreciate that the camera <NUM> and the transducer <NUM> can be placed so that both are facing vertically upward from below the target <NUM>. In another aspect, the camera <NUM> and the transducer <NUM> may be positioned so that both are facing horizontally from the side of the target <NUM>.

The camera <NUM> is single camera and the sounder is a single beam echo sounder. Further, the camera may be a stereo type camera and the sounder may be dual beam sounder or multi-beam sounder. The sounder includes the transducer <NUM>, a transmitter, and a receiver that work as per their pre-specified profile. On activation of the apparatus <NUM>, the transmitter of the sounder generates a transmission signal at different time interval or ping as per requirement and the transducer <NUM> converts the transmission signal into a transmission wave that gets transmitted into water. The transmission wave after getting reflected from a target <NUM>, such as fish (hereinafter target and fish are used interchangeably) is received by the transducer <NUM> to convert the reflected wave into a reception signal. Accordingly, the transducer <NUM> generates the reception signal based on the reflected wave of the transmission wave on the target <NUM>. Based on the received reception signal, the sounder captures echo data of the target <NUM>.

Simultaneous to this capturing of the echo data by the sounder, the camera <NUM> facing a first direction (x-direction) captures picture data of the target <NUM>. The captured echo data and the picture data of the target <NUM> can be used to measure weight of the fish <NUM> in the aquaculture. The process of measurement of the weight of the fish <NUM> from the echo data and the picture data is described in detail with reference to the description of <FIG>.

<FIG> illustrates a block diagram of the target measuring apparatus <NUM> in accordance with an embodiment of the present disclosure. The target measuring apparatus <NUM> includes the camera <NUM>, the transducer <NUM> of the sounder, and a target measuring system <NUM>. The target measuring system <NUM> includes a first length measuring module <NUM>, a target distance measuring module <NUM>, a second and third length measuring module <NUM>, and a weight measuring module <NUM>.

The transducer <NUM> transmits a transmission wave into water and generates a reception signal 104a based on a reflected wave of the transmission wave on the target <NUM>. Simultaneously, the camera <NUM> takes a picture data 102a of the target <NUM>, where the camera <NUM> and the transducer <NUM> are positioned facing a first direction (x-direction).

The first length measuring module <NUM> receives the reception signal (which may also be referred to as echo data) from the transducer <NUM> to measure a first length (height) 106a of the target <NUM>. The first length 106a is being measured in a direction parallel with the first direction (x-direction).

The target distance measuring module <NUM> measures a target distance 102b between the camera <NUM> and the target <NUM> based on the reception signal received from the transducer <NUM>. As mentioned previously, the camera <NUM> and the transducer <NUM> of the sounder are positioned at the same level in a vertical direction and are facing vertically downward from above the target <NUM>.

The second and third length measuring module <NUM> measures a second length (length) 106b and a third length (width) 106c of the target <NUM> based on the picture data 102a and the target distance 102b. The second length 106b is being measured in a second direction (y-direction), and the third length 106c is being measured in a third direction (z-direction) perpendicular to the second direction (y-direction), where the second and third directions form a plane perpendicular to the first direction (x-direction).

The first length 106a of the target <NUM> generated by first length measuring module <NUM> and the second length 106b and the third length 106c of the target <NUM> generated by the second and third length measuring module <NUM> are fed to the weight measuring module <NUM> to measure a weight 106d of the target <NUM>.

In an aspect, the target measuring apparatus <NUM> may include a display device (not shown in <FIG>) to display results of measurement. The camera <NUM> and the transducer <NUM> are connected with the target measuring system <NUM> over wire or wireless network to send the captured picture data 102a and the reception signal 104a, respectively. The camera <NUM> and the transducer <NUM> are connected with the target measuring system <NUM> through an interface (not shown in <FIG>). Also, although the camera <NUM> and the transducer <NUM> are shown in the vicinity of the target measuring system <NUM>; however, without deviating from the scope of the present disclosure, the target measuring system <NUM> may be positioned at a remote location from the camera <NUM> and the transducer <NUM>. In another scenario, more than one pair of camera and transducer may be connected to the remotely located target measuring system so that the target measuring system can be utilized for measurement of weight of fishes present in differently located cages in which aquaculture is performed.

Various components of the target measuring system <NUM> are represented in <FIG>. In an example, the system <NUM> is in communication with the camera <NUM> and/or with the transducer <NUM> through a communication network.

The system <NUM> includes one or more processor(s) <NUM>. The one or more processor(s) <NUM> may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, logic circuitries, and/or any devices that manipulate data based on operational instructions. Among other capabilities, the one or more processor(s) <NUM> are configured to fetch and execute computer-readable instructions stored in a memory <NUM> of the system <NUM>. The memory <NUM> may store one or more computer-readable instructions or routines, which may be fetched and executed to measure the weight of the target <NUM>. The memory <NUM> may include any non-transitory storage device including, for example, volatile memory, such as RAM, or non-volatile memory, such as EPROM, flash memory, and the like.

The system <NUM> also includes an interface(s) <NUM>. The interface(s) <NUM> may include a variety of interfaces, for example, interfaces for data input and output devices, referred to as I/O devices, storage devices, and the like. The interface(s) <NUM> facilitate communication of the system <NUM> with various devices coupled to the system <NUM>. The interface(s) <NUM> may also provide a communication pathway for one or more components of the system <NUM>. Examples of such components include, but are not limited to, module(s) <NUM> and data <NUM>.

The module(s) <NUM> may be implemented as a combination of hardware and programming (for example, programmable instructions) to implement one or more functionalities of the module(s) <NUM>. In implementations described herein, such combinations of hardware and programming may be implemented in several different ways. For example, the programming for the module(s) <NUM> may be processor executable instructions stored on a non-transitory machine-readable storage medium and the hardware for the module(s) <NUM> may include a processing resource (for example, one or more processors), to execute such instructions. In the present implementations, the machine-readable storage medium may store instructions that, when executed by the processing resource, implement module(s) <NUM>. In such examples, the target measuring system <NUM> may include the machine-readable storage medium storing the instructions and the processing resource to execute the instructions, or the machine-readable storage medium may be separate but accessible to target measuring system <NUM> and the processing resource. In other examples, the module(s) <NUM> may be implemented by electronic circuitry.

The data <NUM> includes data that is either stored or generated as a result of functionalities implemented by any of the module(s) <NUM>. In an aspect, the module(s) <NUM> include the first length measuring module <NUM>, the target distance measuring module <NUM>, the second and third length measuring module <NUM>, the weight measuring module <NUM>, and other module(s) <NUM>. The other module(s) <NUM> may implement functionalities that supplement applications or functions performed by the target measuring system <NUM>.

Further, the data <NUM> may include processed data <NUM> and pre-stored data <NUM>. The processed data <NUM> is generated data, for example, target distance, picture data, reception signal as an output result of functionalities implemented by one of the modules <NUM> and devices. On the other hand, the pre-stored data <NUM> includes data, such as speed of sound in the water, focal length of camera, model/fish species specific coefficient which is pre-stored in the system to be used by the modules <NUM> during processing.

In operation, both the camera <NUM> and the transducer <NUM> are synchronized with each other to acquire picture data 102a and the reception signal 104a simultaneously. Further, as shown in <FIG>, the coverage area of the transducer <NUM> is thinner than the coverage area of the camera <NUM>, thereby the coverage area of the transducer <NUM> is included within the coverage area of the camera <NUM>. Accordingly, the transducer <NUM> and the camera <NUM> are having an overlapping portion as shown in <FIG> in accordance with an implementation of the present disclosure.

In a scenario in which the camera <NUM> and the transducer <NUM> are facing the first direction (x-direction) to acquire picture data 102a and reflection wave that generates reception signal 104a, the target measuring system <NUM> selects the target <NUM> which is close to the centre of the picture 102a taken by the camera <NUM>. The target measuring system <NUM> also selects the target <NUM> which has substantially a straight body on the picture 102a, the aim being to discard the target <NUM> that is bending its body on the picture 102a so that the second and third length measuring module <NUM> can accurately perform measurement of the second length 106b and third length 106c. Upon selection of the target <NUM>, the target distance measuring module <NUM> measures target distance, i.e., Fish dist. 102b from the transducer <NUM> to the selected target, i.e., fish with the reception signal 104a. The target distance measuring module <NUM> measures the target distance 102b in parallel to the first direction (x-direction). The target distance measuring module <NUM> measures time difference (t) <NUM> (as shown in <FIG>) between the timing at which the transmission wave or transmission pulse <NUM> is transmitted from the transducer <NUM> and the timing at which echo, i.e., Fish echo <NUM> from the target <NUM>, is received by the transducer <NUM> as shown in <FIG>. The target distance measuring module <NUM> calculates the Fish dist. 102b based on equation <NUM>: <MAT> Where c is speed of sound in water which is pre-stored in the pre-stored data <NUM>.

As mentioned previously, the camera <NUM> and the transducer <NUM> are positioned at the same level in the vertical direction, thereby the target distance measuring module <NUM> sets the result obtained from equation <NUM> as the target distance 102b, namely the distance between the camera <NUM> and the target <NUM>.

In another embodiment, when there is position difference between the camera <NUM> and the transducer <NUM> in the x-direction, the position difference is required to be corrected in order to know the distance from the camera <NUM> to the target <NUM>. For example, if the transducer <NUM> is positioned below the camera <NUM>, position difference between the camera <NUM> and the transducer <NUM> is added in the calculated Fish dist.

Referring to <FIG> and <FIG> together, the first length measuring module <NUM> measures the first length 106a (which may also be referred to as target/fish height 'H') by measuring duration (t echo) <NUM> of the fish echo <NUM> using equation <NUM>: <MAT>.

The measured target height 'H' 106a may be stored in the processed data <NUM> for further processing.

In another embodiment, the target/fish height H 106a can be measured using at least a part of the reception signal (δt) <NUM> between two positions within the fish echo <NUM> instead of using the whole duration of the fish echo <NUM>. For example, referring to <FIG>, the at least a part of the reception signal (δt) <NUM> between the first peak occurring in the fish echo <NUM> and the highest peak occurring in the fish echo <NUM> can be used, where the first peak indicates the position of the back of the fish <NUM> whereas the highest peak indicates the position of the swimbladder of the fish <NUM>. Knowing the fish species, the at least a part of the reception signal δt can be converted into fish height (H) using the equation <NUM>: <MAT> where coefficient fs is specific to the fish species. The coefficient 'fs' of a plurality of fishes is pre-stored in the pre-stored data <NUM> for processing.

The second and third length measuring module <NUM> then detects head and tail of the target <NUM> on the picture 102a taken by the camera <NUM> and measures the second length (which may also be referred to as real length 'L') 106b of the target <NUM> in the second direction (y-direction). The second length of the target <NUM> is a longitudinal size of the target <NUM>. The real length of the target (fish length) 106b can be measured knowing the focal length (f) of the camera <NUM> that is pre-stored in the pre-stored data <NUM>, the distance between the head and the tail of the fish on the picture 102a (Lpicture), and the distance between the camera <NUM> and the fish (i.e., Fish dist. 102b) calculated by the target distance measuring module <NUM> and stored in the processing data <NUM>. Further, the real length 'L' 106b of the target is determined by equation <NUM>.

The second and third length measuring module <NUM> detects both sides (i.e., flanks) of the target <NUM> in the third direction (z-direction) on the picture 102a taken by the camera <NUM> and measures the third length (which may also be referred to as real width 'D') 106c of the target <NUM> in the third direction (z-direction). The third length of the target <NUM> is a lateral size of the target <NUM>. The real width of the target 106c can be measured knowing the focal length (f) of the camera <NUM> that is pre-stored in the pre-stored data <NUM>, the distance between both sides (i.e., flanks) of the fish in the third direction (z-direction) on the picture 102a (Dpicture), and the distance between the camera <NUM> and the fish (i.e., Fish dist. 102b) calculated by the target distance measuring module <NUM> and stored in the processing data <NUM>. Further, the real width 'D' 106c of the target is determined by equation <NUM>.

The first length of the target, i.e., height H of target is being measured in the first direction (x-direction), the second length of the target, i.e., length L of the target is being measured in the second direction (y-direction), and the third length of the target, i.e., width D of the target is being measured in the third direction (z-direction), where the third direction (z-direction) is perpendicular to the second direction (y-direction) and second and the third directions are forming a plane perpendicular to the first direction (x-direction).

The weight measuring module <NUM> is coupled with the first length measuring module <NUM> and the second and third length measuring module <NUM> to receive the target length L 106b, the target width D 106c, and the target height H 106a. The weight measuring module <NUM> then measures the fish weight W using equation <NUM>: <MAT> where a, b, c , d are coefficients adapted beforehand and pre-stored in the pre-stored data <NUM> of the target weight measuring system <NUM> with respect to each fish species. Further, the pre-stored data <NUM> of the system <NUM> has a plurality of models corresponding to a plurality of fish species which are pre-stored along with corresponding coefficient values.

In a case when the camera <NUM> and the transducer <NUM> are facing vertically down, there is the possibility that the target <NUM> is not swimming horizontally (i.e., going up or down) and therefore not swimming perpendicularly to the optical axis of the camera <NUM>. In this case, the target length L 106b appears shorter than the real length of the target <NUM>. In order to reject the target <NUM> that is in this case, the target distance is measured on <NUM> or more pings and the target <NUM> is discarded if the distance change between <NUM> pings is beyond a predefined threshold.

In another embodiment as shown in <FIG>, the camera <NUM> and the transducer <NUM> are placed so that they are facing horizontally from the side of the target <NUM>. In the present case, there is the possibility that the fish is not swimming in a direction perpendicular to the optical axis of the camera <NUM>, as shown in the <FIG>. In this case, the fish length measured by the camera <NUM> would appear shorter.

To calculate the accurate target length, the target <NUM> is detected on two or more pings by the sounder and the target distance 102b is measured on each ping. If the distance change between two pings is close to <NUM>, it means that target is swimming roughly perpendicularly to the optical axis of the camera <NUM> and accurate target length can be anticipated. On the other hand, if the distance change between two pings is beyond a predefined threshold, the target length cannot be measured accurately and therefore, the target is discarded.

<FIG> illustrates a method <NUM> for measuring weight of target in aquaculture environment according to an implementation of the present disclosure. The order in which the method <NUM> is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any appropriate order to carry out the method <NUM> or an alternative method. Additionally, individual blocks may be deleted from the method <NUM> without departing from the scope of the subject matter described herein. The present method <NUM> illustrates particular process for weight measuring of a target, i.e., fish in the aquaculture environment.

In the present embodiment, both the camera <NUM> and the transducer <NUM> are facing first direction in which first length is measured.

At block <NUM>, the method <NUM> includes measuring of first length, i.e., height 'H' 106a of the target. The first length measuring module <NUM> measures the first length of the target <NUM> based on a reception signal generated by the transducer <NUM> from a reflection wave of a transmission wave on the target <NUM>. The first length measuring module <NUM> uses the reception signal to measure the first length using either equation <NUM> or equation <NUM>.

At block <NUM>, the method <NUM> includes measuring of target distance 102b between the camera <NUM> and the target <NUM>. The target distance measuring module <NUM> measures the target distance between the camera <NUM> and the target <NUM> based on the reception signal 104a and the equation <NUM>.

At block <NUM>, the method <NUM> includes measuring second and third length of the target. The second and third length measuring module <NUM> measures second length, i.e., target length 'L' 106b in the second direction (y-direction) by detecting head and tail of the target <NUM> on the picture 102a taken by the camera <NUM>. The second and third length measuring module <NUM> measures third length, i.e., target width 'D' 106c in the third direction (z-direction) by detecting both sides of the target <NUM> on the picture 102a taken by the camera <NUM>.

Claim 1:
A target measuring apparatus (<NUM>), comprising:
a transducer (<NUM>) configured to transmit a transmission wave (<NUM>) into water and configured to generate a reception signal (104a) based on a reflection wave of the transmission wave (<NUM>) on a target (<NUM>);
a camera (<NUM>) configured to take a picture (102a) of the target (<NUM>), the camera (<NUM>) and the transducer (<NUM>) both facing a first direction (x-direction); and
a target measuring system (<NUM>) coupled to the transducer (<NUM>) and the camera (<NUM>), wherein the target measuring system (<NUM>) comprises a weight measuring module (<NUM>) configured to measure a weight of the target (<NUM>),
characterised in that:
the target measuring system (<NUM>) comprises a first length measuring module (<NUM>) configured to measure a first length (106a) of the target (<NUM>) based on the reception signal (104a), the first length (106a) being measured in a direction parallel with the first direction (x-direction);
the target measuring system (<NUM>) comprises a target distance measuring module (<NUM>) configured to measure the target distance (102b) between the camera (<NUM>) and the target (<NUM>) based on the reception signal (104a);
the target measuring system (<NUM>) further comprises a second and third length measuring module (<NUM>) configured to measure a second length (106b) and a third length (106c) of the target (<NUM>) based on the picture (102a) and the target distance (102b) measured by the target distance measuring module (<NUM>), the second length (106b) being measured in a second direction (y-direction), the third length (106c) being measured in a third direction (z-direction) perpendicular to the second direction (y-direction), the second and third directions forming a plane perpendicular to the first direction (x-direction); and
the weight measuring module (<NUM>) is configured to measure the weight of the target (<NUM>) based on the first length (106a) of the target (<NUM>) measured by the first length measuring module (<NUM>), and the second and third lengths (106b, 106c) of the target (<NUM>) measured by the second and third length measuring module (<NUM>).