Remaining quantity estimation system

Abstract

To provide a remaining quantity estimation system capable of more accurately estimating the remaining quantity of an accommodated article.SOLUTION: A remaining quantity estimation system is attached to a container T in which an accommodated article C is stored and estimates the remaining quantity of the accommodated article C. The remaining quantity estimation system includes: a sensor unit 6 that measures a distance df to the accommodated article C by measuring the time for a transmitted radio wave to be reflected by a surface F of the accommodated article C and then received, and outputs measurement result information indicating the measured distance; and a remaining quantity estimation unit that estimates the remaining quantity based on the measurement result information. The remaining quantity estimation unit estimates the remaining quantity without using any measured distance that is equal to or shorter than a first threshold value d1 that is set in advance according to specifications of the sensor unit 6 and / or the container T, among measured distances indicated by the measurement result information.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a remaining amount estimation system.

Background Art

[0002] Patent Document 1 discloses an inventory quantity notification system for managing the remaining amount of kerosene stored in a general household or the like. The inventory quantity notification system disclosed in Patent Document 1 includes an inventory quantity detection means such as a pressure sensor, a transmission terminal that transmits data on the remaining amount of kerosene detected by the inventory quantity detection means wirelessly or the like, a reception terminal that receives the data on the remaining amount of kerosene transmitted from the transmission terminal, and an inventory quantity management device that stores the data on the remaining amount received from the reception terminal and notifies the remaining amount of kerosene.

[0003] Patent Document 2 discloses an inventory quantity estimation method for estimating the inventory quantity in a storage tank storing a solid, a liquid, or a mixture thereof from the indicated value of a level meter such as an ultrasonic sensor. The inventory quantity estimation method disclosed in Patent Document 2 includes a first step of conducting a model experiment in accordance with the scale of a reduced-scale model of the storage tank to obtain the relationship between the indicated value of the level meter and the inventory quantity in the actual storage tank, a second step of measuring the height of the stored material in the actual storage tank with the level meter, and a third step of estimating the inventory quantity of the actual storage tank from the relationship between the indicated value of the level meter obtained from the actual storage tank and the inventory quantity corresponding to the indicated value of the level meter in the actual storage tank obtained by the model experiment.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the technologies disclosed in Patent Document 1 and Patent Document 2, sensors are used to estimate the remaining amount of the contained substance (kerosene in Patent Document 1 and stored substance in Patent Document 2). Among the sensors, there are also sensors with regions that cannot be accurately detected due to sensitivity characteristics and the like. Depending on the sensor used, there are problems such as the remaining amount of the contained substance cannot be accurately estimated.

[0006] Therefore, there is a need for a remaining amount estimation system that can more accurately estimate the remaining amount of the contained substance.

Means for Solving the Problems

[0007] The characteristic configuration of the remaining amount estimation system according to the present invention is a remaining amount estimation system that is attached to a container in which a contained substance is stored and estimates the remaining amount of the contained substance. By measuring the time until the transmitted radio wave is reflected by the surface of the contained substance and received, the distance to the contained substance is measured, and a sensor unit that outputs measurement result information indicating the measured distance, and a remaining amount estimation unit that estimates the remaining amount based on the measurement result information. The remaining amount estimation unit estimates the remaining amount without using the measurement distance that is equal to or less than a first allowable threshold value preset according to the specifications of the sensor unit and / or the container among the measurement distances indicated by the measurement result information.

[0008] With such a characteristic configuration, the estimation of the remaining amount is performed without using the measurement distance that is equal to or less than a first allowable threshold value preset according to the specifications of the sensor unit (for example, a region that cannot be accurately measured due to the sensitivity characteristics of the sensor unit, etc.) and the specifications of the container (for example, a region that cannot be accurately measured due to the size of the container, the shape of the container, etc.). Therefore, the remaining amount of the contained substance can be estimated more accurately.

[0009] Further, the remaining amount estimation unit determines whether or not the measurement distance exceeds a second allowable threshold value preset based on the bottom surface distance indicating the distance between the sensor unit and the bottom surface of the container. When it is determined that the measurement distance exceeds the second allowable threshold value, it is preferable to estimate that the remaining amount of the contained substance is full.

[0010] When a container houses a content having a relative permittivity greater than that of air, the measured distance to the bottom surface indicated by the measurement result information output from the sensor unit becomes larger than the actual bottom surface distance, and a value exceeding the second allowable threshold is output as the measured distance. By utilizing such a phenomenon, when the measured distance exceeds the second allowable threshold set in advance based on the bottom surface distance, it is possible to determine that the remaining amount of the content is full, and the remaining amount of the content can be estimated more accurately.

[0011] Further, when the remaining amount estimation unit determines that the measured distance is equal to or less than the first allowable threshold, it is preferable to estimate that the remaining amount of the content is full.

[0012] With such a configuration, even when the reflected wave reflected from the bottom surface is attenuated by the size and type of the content and is not received by the sensor unit, or is not detected (determined to be received) by the sensor unit, it is possible to determine that the remaining amount of the content is full, and the remaining amount of the content can be estimated more accurately.

[0013] Further, when the remaining amount estimation unit determines that the measured distance is equal to or less than the second allowable threshold, it determines whether the measured distance is included in a preset allowable range with respect to the bottom surface distance. When it is determined that the measured distance is included in the allowable range, it is preferable to estimate that the remaining amount is empty.

[0014] With such a configuration, by determining whether the measured distance is included in a preset allowable range with respect to the bottom surface distance, it is possible to estimate that the remaining amount is empty, and the remaining amount of the content can be estimated more accurately.

[0015] Further, when the remaining amount estimation unit determines that the measured distance is not included in the allowable range, it is preferable to estimate the remaining amount based on the measured distance.

[0016] With such a configuration, since the remaining amount of the content is obtained by calculation when the content is neither full nor empty, the remaining amount of the content can be estimated more accurately.

[0017] Also, it is preferable that the bottom surface distance is the measurement result information acquired by the sensor unit in a state where the container is not filled with the contents.

[0018] With such a configuration, since the value actually measured and acquired by the sensor unit attached to the container can be set as the bottom surface distance, the remaining amount of the contents can be estimated more accurately.

[0019] Also, it is preferable that the bottom surface distance is container-specific information based on the specifications of the container.

[0020] With such a configuration, since the bottom surface distance can be set based on the specifications of the container such as catalog values, the operation for attaching the sensor unit to the container to acquire (measure) the bottom surface distance becomes unnecessary, and the complication of the operation can be avoided.

[0021] Also, it is preferable to further include a storage unit capable of storing the container-specific information.

[0022] With such a configuration, for example, the operation for executing communication to acquire the container-specific information between the container and an external device that stores the container-specific information becomes unnecessary, and the responsiveness of the sensor unit can be enhanced.

[0023] Also, it is preferable to further include an input unit capable of inputting the container-specific information.

[0024] With such a configuration, for example, the operation for attaching the sensor unit to the container to acquire (measure) the bottom surface distance becomes unnecessary, and the complexity of the operation can be avoided.

[0025] Also, it is preferable that the contents are organic substances.

[0026] With such a configuration, the remaining amounts of various organic substances can be estimated as the contents.

Brief Description of the Drawings

[0027]

Figure 1

Figure 2

Figure 3

Figure 4

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Figure 6A

Figure 6B

Figure 6C

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Figure 8

Figure 9

Mode for Carrying Out the Invention

[0028] Hereinafter, a remaining amount estimation system including a remaining amount estimation device according to an embodiment of the present invention will be described. Note that each component of the embodiment described below can be combined with each other as long as they do not contradict each other. In addition, the materials, shapes, dimensions, numbers, arrangements, etc. of the components constituting each aspect of the embodiment described below are merely examples, and can be arbitrarily designed and modified as long as the same functions can be realized.

[0029] [Remaining Amount Estimation System] With reference to FIGS. 1 to 3, the schematic configuration of the remaining amount estimation system 200 including the remaining amount estimation device 100 will be described. FIG. 1 is a diagram showing the schematic configuration of the remaining amount estimation system 200. FIG. 2 is a perspective view showing the configuration of the container T and the remaining amount estimation device 100, and FIG. 3 is a cross-sectional view of the state where the remaining amount estimation device 100 is attached to the container T shown in FIG. 2.

[0030] As shown in FIG. 1, in addition to the remaining amount estimation device 100 that estimates the remaining amount Ra of the contained substance C (see FIG. 3) contained in the container T (see FIG. 2), the remaining amount estimation system 200 includes a first external device 201 and a second external device 202 that are configured to be communicable with the remaining amount estimation device 100.

[0031] [First External Device] The first external device 201 is, for example, a monitoring device for monitoring the remaining amount Ra of the contained substance C. The first external device 201 can communicate with the remaining amount estimation device 100 in accordance with a long-distance wireless standard corresponding to a first communication distance (1 km or more in this embodiment). In this embodiment, the first external device 201 is a server existing on a network such as a cloud server provided by a telecommunications carrier or the like, and is configured to be communicable with the remaining amount estimation device 100 via a base station.

[0032] [Second External Device] The second external device 202 is, for example, a maintenance management device for performing maintenance on the remaining amount estimation device 100. The second external device 202 can communicate with the remaining amount estimation device 100 in accordance with a short-distance wireless standard corresponding to a second communication distance (up to 300 m in this embodiment). In this embodiment, the second external device 202 is an information processing terminal such as a mobile phone or a smartphone, and is configured to be communicable with the remaining amount estimation device 100 at a visually observable distance (range) from the remaining amount estimation device 100.

[0033] [Container] As shown in FIGS. 2 and 3, the container T has a container main body portion T1, a cylindrical opening portion T2 protruding from the container main body portion T1, and a lid portion T3 that closes the opening portion T2. In this embodiment, the container T is a kerosene tank, and the contained substance C is kerosene.

[0034] The container body part T1 includes a bottom surface T11, a side surface T12, and an upper surface T13, and a storage space TS (see FIG. 3) for storing (reserving) the content C is formed by the bottom surface T11, the side surface T12, and the upper surface T13. The opening T2 communicates the storage space TS with the outside of the container T. The opening T2 is disposed on the upper surface T13 facing the bottom surface T11 of the container body part T1 and protrudes in a direction away from the bottom surface T11 with respect to the upper surface T13 (a direction orthogonal to the upper surface T13). The opening T2 has, for example, a diameter (inner diameter) of 50 mm or more and 65 mm or less, and has a small area with respect to the upper surface T13 when viewed from a direction orthogonal to the upper surface T13. The upper surface T13 is, for example, 5000 mm 2 or more and 7000 mm 2 or less.

[0035] The content C is supplied to the storage space TS through the opening T2 and is stored (reserved) in the storage space TS. The opening T2 is configured such that the lid part T3 can be attached, and is closed when the lid part T3 is attached. The lid part T3 contains resin as a material, and the remaining amount estimating device 100 is attached to the lid part T3. That is, the remaining amount estimating device 100 is disposed facing the bottom surface T11 of the container body part T1.

[0036] In the following, in a state where the lid part T3 to which the remaining amount estimating device 100 is attached is attached to the opening T2, the direction from the remaining amount estimating device 100 toward the bottom surface T11 of the container body part T1 is referred to as the "vertical direction Z", the side on which the bottom surface T11 is disposed in the vertical direction Z is referred to as the "lower side Z1", and the opposite side (the side on which the remaining amount estimating device 100 is disposed) is referred to as the "upper side Z2".

[0037] [Remaining amount estimating device] The remaining amount estimating device 100 estimates the remaining amount Ra of the content C stored in the container T. FIGS. 4 and 5 are exploded perspective views of the remaining amount estimating device 100.

[0038] As shown in FIGS. 4 and 5, the remaining amount estimation device 100 includes a housing 1, a lens unit 2, a substrate 3, a power supply unit 4 (see FIG. 5), a control unit 5 (see FIG. 5), a sensor unit 6 (see FIG. 4), a memory unit 7 (see FIG. 5), a remaining amount estimation unit 8 (see FIG. 5), and a communication unit 9 (see FIG. 5). Note that the communication unit 9 is an example of an input unit.

[0039] [Housing] The housing 1 is insulating and contains resin as a material. As shown in FIG. 3, the housing 1 is arranged to cover the lid portion T3 of the container T and is held by the lid portion T3. The housing 1 forms a housing space 1S (see FIG. 4) that houses the lens unit 2, the substrate 3, the power supply unit 4, the control unit 5, the sensor unit 6, the memory unit 7, the remaining amount estimation unit 8, and the communication unit 9 between the housing 1 and the lid portion T3. In the present embodiment, the housing space 1S is configured to be watertight. The housing space 1S is configured to be watertight, for example, by applying a sealing material such as an adhesive or grease to the gap between the lid portion T3 and the housing 1.

[0040] [Lens Unit] The lens unit 2 shown in FIGS. 4 and 5 improves the sensitivity of the sensor unit 6. The lens unit 2 includes a lens 21 (convex lens) and a lens holder 22 that holds the lens 21. The lens 21 is a resin lens made of resin and is held by the lens holder 22 so as to face the sensor unit 6 in a posture where the container T side bulges. In the present embodiment, the lens holder 22 is configured separately from the lid portion T3 and is supported by the lid portion T3 of the container T. Note that the lens holder 22 may be configured integrally with the lid portion T3.

[0041] [Substrate] The power supply unit 4, the control unit 5, the sensor unit 6, the memory unit 7, the remaining amount estimation unit 8, and the communication unit 9 are mounted on the substrate 3. In the present embodiment, the sensor unit 6 is arranged on one first surface 31 of the substrate 3 (see FIG. 4), and the power supply unit 4, the control unit 5, the memory unit 7, the remaining amount estimation unit 8, and the communication unit 9 are arranged on the other second surface 32 of the substrate 3 (see FIG. 5). The substrate 3 is housed in the housing 1 such that the side (first surface 31) on which the sensor unit 6 is arranged becomes the lower side Z1 and is attached to the lid portion T3 (see FIG. 3).

[0042] [Power supply unit] The power supply unit 4 supplies power to each part of the remaining amount estimation device 100. The power supply unit 4 includes a power supply circuit 41 and a battery unit 42. The power supply circuit 41 converts the power from the battery unit 42 (DC-AC conversion and / or voltage conversion), and supplies the converted power to each part of the remaining amount estimation device 100 (control unit 5, sensor unit 6, storage unit 7, remaining amount estimation unit 8, and communication unit 9). In the present embodiment, the battery unit 42 is a built-in primary battery, but the battery unit 42 may be a secondary battery, or a combination of a self-power generating device and a secondary battery.

[0043] [Control unit] The control unit 5 can control the operations of each part of the remaining amount estimation device 100. The control unit 5 can perform power supply control for the power supply unit 4 and communication control for the communication unit 9. The control unit 5 can also update the firmware of devices such as the sensor unit 6 and the communication unit 9. Note that the control unit 5 is composed of a microcontroller equipped with a processor or the like.

[0044] [Sensor unit] The sensor unit 6 outputs estimation source information C1 used for estimating the remaining amount Ra of the content C contained in the container T. In the present embodiment, the sensor unit 6 is a distance measurement sensor (millimeter wave sensor for distance measurement) that measures the distance to the measurement target using radio waves (millimeter waves). As shown in FIG. 3, the sensor unit 6 measures the time from when the radio wave transmitted from the transmission unit of the sensor unit 6 is reflected by the reflecting surface until it is received by the receiving unit (light receiving element) of the sensor unit 6. That is, the sensor unit 6 is a ToF (Time Of Flight) type level sensor, and can measure the distance to the content C in a non-contact manner. Note that the radio wave transmission and reception efficiency of the sensor unit 6 is improved when the radio wave passes through the lens 21 of the lens unit 2.

[0045] The reflecting surface includes the boundary surface F of the contained substance C (the liquid level of kerosene in this embodiment), the bottom surface T11 of the container T, and the wall surface forming the opening T2 of the container T, etc. In this embodiment, the relative permittivity εr of the contained substance C is "2", which is greater than the relative permittivity εr of air "1 (approximately 1)". That is, the relative permittivity εr changes at the boundary surface F of the contained substance C. It is preferable that the gas (air) existing between the sensor unit 6 and the boundary surface F does not contain water vapor.

[0046] The sensor unit 6 outputs measurement result information C2 (see FIGS. 6A to 6C) indicating the distance to the measurement object based on the measured time.

[0047] Each of FIGS. 6A to 6C is a diagram showing an example of the measurement result information C2 output by the sensor unit 6. The vertical axis shown in each of FIGS. 6A to 6C is the reflection intensity Ri of the radio wave transmitted from the sensor unit 6 is shown, and the horizontal axis shows the measurement distance ds between the sensor unit 6 and the reflecting surface. FIG. 6A shows an example of the measurement result information C2 output from the sensor unit 6 when the remaining amount Ra of the contained substance C is estimated to be full. FIG. 6B shows an example of the measurement result information C2 output from the sensor unit 6 when the remaining amount Ra of the contained substance C is estimated to be empty. FIG. 6C shows an example of the measurement result information C2 output from the sensor unit 6 when the remaining amount Ra of the contained substance C is estimated as a specific amount that is neither full nor empty. Here, the full amount is, for example, the remaining amount Ra of the contained substance C when the capacity of the contained substance C accommodated in the storage space TS is equal to the storable capacity of the container T (hereinafter referred to as the "storable capacity"). Empty means, for example, the remaining amount Ra of the contained substance C when the capacity of the contained substance C accommodated in the storage space TS is "0". However, the capacity of the contained substance C when estimating as full and the capacity of the contained substance C when estimating as empty can be adjusted by the administrator of the remaining amount estimating device 100, etc., and it is also possible to provide an allowable range described later. When the contained substance C is at the remaining amount Ra of the storable capacity, it is preferable to set the full state of the contained substance C so that there is an air region of about several centimeters between the lid portion T3 and the contained substance C.

[0048] As shown in FIGS. 6A to 6C, in the present embodiment, two threshold values (a first threshold value d1 and a second threshold value d2) are set for the measurement distance ds (the distance between the reflecting surface from which the radio wave is reflected and the sensor unit 6) indicated by the measurement result information C2 output from the sensor unit 6.

[0049] [First Threshold Value] The first threshold value d1 is a threshold value set in advance according to the specifications of the sensor unit 6 and / or the container T. Specifically, the first threshold value d1 is set in advance by an administrator or the like based on the sensitivity characteristics of the sensor unit 6 (the distance from the sensor unit 6 at which the distance measurement of the sensor unit 6 becomes unstable), the shape of the container T (for example, the shape of the opening T2), the size of the container T (for example, the size of the opening T2), and the like. In the present embodiment, as the first threshold value d1, the distance between the first division line L1 shown in FIG. 3 and the sensor unit 6 is set in consideration of the sensitivity characteristics of the sensor unit 6 (whether the sensor unit 6 can output an accurate value).

[0050] The first division line L1 is, for example, a boundary between a region including the measurement distance ds output by the sensor unit 6 that has received radio waves reflected by a wall surface (other than the boundary surface F and the bottom surface T11) constituting the opening T2 as a reflecting surface, and a region including the measurement distance ds output by the sensor unit 6 that has received radio waves reflected by a reflecting surface other than the wall surface constituting the opening T2 and being the boundary surface F or the bottom surface T11, and is set in consideration of the sensitivity characteristics of the sensor unit 6. In the present embodiment, the first division line L1 is set in consideration of the sensitivity characteristics of the sensor unit 6 when the boundary surface F (liquid surface) of the contained substance C is estimated (regarded as) to be the full amount when the remaining amount Ra of the contained substance C is the full amount, and in the example shown in FIG. 3, it is set at a position separated from the lower end of the opening T2 by a preset distance. However, the first division line L1 may be set at the lower end of the opening T2.

[0051] [Second Threshold Value] The second threshold value d2 is preset based on the distance (actual distance) between the second division line L2 and the sensor unit 6. In the present embodiment, the second division line L2 is preset by an administrator or the like on the bottom surface T11 of the container T. That is, as the second threshold value d2, a value equal to the actual distance (hereinafter referred to as "bottom surface distance dt") between the sensor unit 6 and the bottom surface T11 is set.

[0052] [Allowable range] In the present embodiment, an allowable range (first allowable range R1 and second allowable range R2) is set for each of the first division line L1 and the second division line L2. Note that the upper limit of the first allowable range R1 (a value larger than that for the first division line L1) is an example of the first allowable threshold value, and the upper limit of the second allowable range R2 (a value larger than that for the second division line L2) is an example of the second allowable threshold value. Also, the second allowable range R2 is an example of the allowable range.

[0053] The first allowable range R1 and the second allowable range R2 are set, for example, so as to straddle each of the first division line L1 and the second division line L2 for each of the first division line L1 and the second division line L2. Specifically, the first allowable range R1 and the second allowable range R2 are values (values corresponding to several centimeters to several tens of centimeters) such that the upper side Z2 (sensor unit 6 side) and the lower side Z1 (bottom surface T11 side) ranges of each of the first division line L1 and the second division line L2 are included. The values set as the first allowable range R1 and the second allowable range R2 are determined in advance by an administrator or the like.

[0054] By setting the first allowable range R1 and the second allowable range R2, individual differences such as the characteristics of the sensor unit 6 (sensor IC) can be absorbed, and a margin can be provided for estimating the remaining amount Ra. For example, by setting the first allowable range R1, variations in the sensitivity characteristics of the sensor unit 6 can be accommodated. Also, for example, by setting the second allowable range R2, when the remaining amount Ra of the contained substance C is extremely small, the remaining amount Ra of the contained substance C can be estimated (regarded as) empty.

[0055] Note that the second allowable range R2 is set to a value such that when the actual remaining amount Ra of the contained object C is full, the measured distance ds indicated by the measurement result information C2 output from the sensor unit 6 exceeds (a value such that the third measurement result information C23 described later is included in the measurement result information C2).

[0056] Hereinafter, with reference to Formula (1) and Formula (2), an example of a method for determining the value set as the second allowable range R2 will be described.

[0057] On the premise that the measured distance ds output from the sensor unit 6 is proportional to the square root of the relative permittivity εr of the medium (the contained object C) through which the radio wave passes with respect to the actual distance dm of the medium (the contained object C) through which the radio wave passes, it is obtained by the following formula (1). ds = dm × √εr ··· Formula (1)

[0058] The measured distance ds output from the sensor unit 6 as the distance between the sensor unit 6 and the bottom surface T11 is obtained by the following formula (2), which is the sum of the distance df of the contained object (see Fig. 3) between the sensor unit 6 and the contained object C and the depth dc1 of the contained object C (a value considering the relative permittivity εr: see Fig. 3). ds = df + dc1 ··· Formula (2) For example, when the bottom surface distance dt (the value indicated by the container-specific information C3) indicating the actual distance between the sensor unit 6 and the bottom surface T11 is "100 cm", the relative permittivity εr of air is "1" (about 1), and the actual distance (distance df of the contained object) between the contained object C with a relative permittivity εr of "2" and the sensor unit 6 is 10 cm or less, and it is assumed (regarded) that the remaining amount Ra of the contained object C is full, the measured distance ds output from the sensor unit 6 as the distance between the sensor unit 6 and the bottom surface T11 is Substituting the values into the above formula (2) respectively, ds = 10 × √1 + (100 - 10) × √2 ≒ 137. Therefore, in order to estimate that the remaining amount Ra of the container C is full when the actual distance (container distance df) between the container C with a relative dielectric constant εr of "2" and the sensor unit 6 is 10 cm or less, a value less than 37 cm (137 cm - 100 cm) may be set as the value of Z1 on the lower side Z1 with respect to the second division line L2 of the second allowable range R2.

[0059] Further, for example, when it is assumed that the remaining amount Ra of the container C is estimated to be empty when the depth dc (actual distance) of the container C is 5 cm or less (the depth dc1 considering the relative dielectric constant is 5 × √2 from Equation (1)), the measurement distance ds can be obtained by substituting the respective values into the above Equation (2). and ds = (100 - 5) × √(1 + 5 × √2) ≈ 102. Therefore, in order to estimate that the remaining amount Ra is empty when the depth dc (actual distance) of the container C is 5 cm or less, a value of 2 cm or more may be set as the value of Z1 on the lower side Z1 with respect to the second division line L2 of the second allowable range R2.

[0060] From the above, if the allowable range of Z1 on the lower side with respect to the second division line L2 is set to a value between more than 2 cm and less than 37 cm, it is possible to estimate that the remaining amount Ra of the container C is full when the actual distance between the container C and the sensor unit 6 is 10 cm or less, and it is possible to accurately estimate that the remaining amount Ra of the container C is empty when the depth dc (actual distance) of the container C is 5 cm or less. Note that by increasing the value set as the second allowable range R2 of Z1 on the lower side with respect to the second division line L2, the actual remaining amount Ra of the container C when it is estimated that the remaining amount Ra of the container C is empty can be increased.

[0061] Note that, hereinafter, as shown in FIGS. 6A to 6C, the region below the upper limit of the first allowable range R1 is referred to as the "first region A1", the region exceeding the upper limit of the first allowable range R1 and below the upper limit of the second allowable range R2 is referred to as the "second region A2", and the region exceeding the upper limit of the second allowable range R2 is referred to as the "third region A3". Among the measurement result information C2 output from the sensor unit 6, the measurement result information C2 included in the first region A1 is referred to as the "first measurement result information C21", the measurement result information C2 included in the second region A2 is referred to as the "second measurement result information C22", and the measurement result information C2 included in the third region A3 is referred to as the "third measurement result information C23".

[0062] The sensor unit 6 outputs the measurement result information C2 including at least one of the first measurement result information C21, the second measurement result information C22, and the third measurement result information C23. The first measurement result information C21 can be output, for example, by the sensor unit 6 that has received radio waves reflected by the wall surface constituting the opening T2 as a reflecting surface. That is, the measurement distance ds indicated by the first measurement result information C21 appearing in the first region A1 may not indicate an accurate value as the distance between the sensor unit 6 and the contained object C, and is not suitable for estimating the remaining amount Ra of the contained object C. Therefore, the measurement distance ds indicated by the first measurement result information C21 (the measurement distance ds included in the first region A1) is not used for estimating the remaining amount Ra of the contained object C. Thereby, a decrease in the accuracy of the sensor unit 6 can be suppressed.

[0063] The second measurement result information C22 can be output, for example, by the sensor unit 6 that has received radio waves reflected by the boundary surface F (liquid surface) or the bottom surface T11 of the container T as a reflecting surface. That is, the second measurement result information C22 appearing in the second region A2 indicates the distance between the sensor unit 6 and the contained object C or the bottom surface T11, and is suitable for estimating the remaining amount Ra of the contained object C. Therefore, the measurement distance ds indicated by the second measurement result information C22 (the measurement distance ds included in the second region A2) is used for the remaining amount Ra of the contained object C.

[0064] The third measurement result information C23 is the measurement result information C2 output due to the change in the radio wave propagation speed (change in the measured distance) caused by the remaining content C. Specifically, when the content C with a relative permittivity εr greater than that of air remains in the container T, it can be output by the sensor unit 6 that receives the radio wave reflected from the bottom surface T11 of the container T as a reflection surface.

[0065] For example, when a radio wave is propagated in a state where the content C is full, the radio wave is propagated only through the content C (without passing through air). In contrast, when a radio wave is propagated in a state where the content C is "0" (empty state), the radio wave is propagated only through air (without passing through the content C). As described above, the relative permittivity εr "2" of the content C is greater than the relative permittivity εr "1" of air. Therefore, the measured distance ds (apparent distance) to the bottom surface T11 of the container T indicated by the measurement result information C2 output from the sensor unit 6 becomes larger than the actual bottom distance dt, and a value exceeding the second threshold d2 (that is, the third measurement result information C23) is output.

[0066] Specifically, the bottom surface distance dt between the sensor unit 6 and the bottom surface T11 is theoretically obtained by the sum of the distance from the sensor unit 6 to the boundary surface F of the contained substance C and the depth dc of the contained substance C. However, as described above, when the contained substance C with a relative permittivity εr greater than "1" remains, the measured distance ds indicated by the measurement result information C2 output from the sensor unit 6 shows a value larger than the actual bottom surface distance dt. That is, the depth dc1 (measured distance ds) of the contained substance C obtained based on the measurement result information C2 output from the sensor unit 6 becomes a value larger than the actual depth dc of the contained substance C. As long as a plurality of media with different relative permittivities εr are not mixed as the contained substance C, the second measurement result information C22 is considered to be one. Therefore, the third measurement result information C23 indicating a distance (value) larger than the second measurement result information C22 is assumed to indicate the distance between the sensor unit 6 and the reflecting surface (bottom surface T11) when the bottom surface T11 is used as the reflecting surface. That is, the measured distance ds indicated by the third measurement result information C23 appearing in the third region A3 does not indicate the distance between the sensor unit 6 and the contained substance C and is not suitable for estimating the remaining amount Ra (specific value) of the contained substance C. Therefore, the measured distance ds (the measured distance ds included in the third region A3) indicated by the third measurement result information C23 is not used for estimating the remaining amount Ra (specific value) of the contained substance C. Although it is also assumed that the third measurement result information C23 is not output depending on the sensitivity characteristics such as the ranging limit distance of the sensor unit 6 (sensor IC), the size of the container T, the relative permittivity εr of the contained substance C, etc., since the third measurement result information C23 is not used for estimating the remaining amount Ra of the contained substance C, it has no influence on the accuracy of estimating the remaining amount Ra of the contained substance C.

[0067] [Storage unit] The storage unit 7 shown in FIGS. 4 and 5 is composed of a non-volatile semiconductor memory or the like. The storage unit 7 is configured to be able to store container-specific information C3 based on the specifications of the container T to which the remaining amount estimation device 100 is attached, and estimation-related information C4 related to the estimation of the remaining amount Ra of the contained substance C stored in the container T. The storage unit 7 also stores information indicating the first threshold value d1, the second threshold value d2, the first allowable range R1, and the second allowable range R2.

[0068] [Container-specific information] The container-specific information C3 is information regarding the specifications (size) unique to the container T. The container-specific information C3 includes information indicating the bottom surface distance dt between the sensor unit 6 fixed to the lid portion T3 and the bottom surface T11 of the container T. In the present embodiment, the container-specific information C3 is acquired by measuring with the sensor unit 6 attached to the lid portion T3 in a state where the container T does not contain the content C (that is, in a state where the remaining amount Ra of the content C is empty). However, the container-specific information C3 may be set based on the specifications (catalog values) of the container T, or may be set to a value actually measured with a measuring tool or the like.

[0069] [Estimation-related information] The estimation-related information C4 is information indicating the relationship between the measurement result information C2 output from the sensor unit 6 and the remaining amount Ra of the content C (see FIG. 7). FIG. 7 is a graph showing an example of the relationship between the depth dc of the content C and the remaining amount Ra of the content C. The horizontal axis shown in FIG. 7 indicates the depth dc of the content C, and the vertical axis indicates the remaining amount Ra of the content C. Note that the depth dc of the content C indicates the actual distance between the boundary surface F of the content C (the sensor unit 6 side (upper side Z2) shown in FIG. 3) and the bottom surface T11 of the container T.

[0070] [Remaining amount estimation unit] The remaining amount estimation unit 8 has a processor such as a CPU (Central Processing Unit). The remaining amount estimation unit 8 estimates the remaining amount Ra of the content C based on the measurement result information C2 output from the sensor unit 6 and the information stored in the storage unit 7 (the container-specific information C3 and the estimation-related information C4). Estimate the remaining amount Ra of the content C.

[0071] In the present embodiment, the remaining amount estimation unit 8 estimates the remaining amount Ra of the content C by utilizing the fact that the propagation speed of the radio wave changes (the measured distance changes) due to the relative dielectric constant εr of the content C as described above. Specifically, as described above, the remaining amount Ra of the content C is estimated by utilizing the fact that the measured distance ds output by the sensor unit 6 that receives the reflected wave reflected by the bottom surface T11 of the container T is larger than the actual bottom surface distance dt (the actual distance between the sensor unit 6 and the bottom surface T11).

[0072] Specifically, as shown in FIGS. 6A to 6C, the remaining amount estimation unit 8 estimates the remaining amount Ra without using the measurement distance ds included in the first region A1 among the measurement distances ds output by the sensor unit 6 (the measurement distance ds that is equal to or less than the upper limit of the first allowable range R1). In the present embodiment, the remaining amount estimation unit 8 estimates the remaining amount Ra of the contained material C by determining whether or not it is included in the second region A2 (a region that exceeds the upper limit of the first allowable range R1 and is equal to or less than the upper limit of the second allowable range R2). Note that when the measurement distance ds indicated by the measurement result information C2 (the second measurement result information C22) is equal to or less than the first allowable range R1, the remaining amount estimation unit 8 may determine that the remaining amount Ra of the contained material C is full.

[0073] When the remaining amount estimation unit 8 determines that the measurement distance ds is not included in the second region A2, it determines whether or not the measurement distance ds exceeds the upper limit of the second allowable range R2. When it determines that the measurement distance ds exceeds the upper limit of the second allowable range R2, it estimates that the remaining amount Ra of the contained material C is full.

[0074] When the remaining amount estimation unit 8 determines that the measurement distance ds output by the sensor unit 6 is included in the second region A2 (the measurement distance ds exceeds the upper limit of the first allowable range R1 and is equal to or less than the upper limit of the second allowable range R2), it determines whether or not the measurement distance ds is included in the second allowable range R2 (equal to or more than the lower limit and equal to or less than the upper limit of the second allowable range R2). When it determines that the measurement distance ds is included in the second allowable range R2 (that is, the measurement distance ds is a value close to the distance between the sensor unit 6 and the bottom surface T11), it estimates that the remaining amount Ra of the contained material C is "0" (empty). On the other hand, when it determines that the measurement distance ds is not included in the second allowable range R2 (that is, the measurement distance ds is a value far from the distance between the sensor unit 6 and the bottom surface T11), it obtains the remaining amount Ra of the contained material C based on the measurement distance ds by calculation.

[0075] [Calculation of remaining amount] When the remaining amount Ra of the contained material C is full, the remaining amount estimation unit 8 outputs remaining amount result information C5 indicating, for example, a value preset as the remaining amount Ra (the capacity of the contained material C when estimated as full). When the remaining amount Ra is empty, the remaining amount estimation unit 8 outputs remaining amount result information C5 indicating "0". Further, when the remaining amount Ra of the contained material C is neither full nor empty, the remaining amount estimation unit 8 calculates the remaining amount Ra of the contained material C and outputs remaining amount result information C5 indicating the calculated result. Note that hereinafter, the process of calculating the remaining amount Ra may be referred to as "remaining amount estimation process".

[0076] [Communication unit] The communication unit 9 can transmit and receive data indicating the remaining amount result information C5 output from the remaining amount estimation unit 8. The communication unit 9 has an antenna (not shown). The antenna can be, for example, an antenna member mounted on the substrate 3, a pattern antenna formed on the surface of the substrate 3, an antenna built in a communication IC mounted on the substrate 3, or may be connected by a communication electric wire or the like to an antenna member disposed within the accommodation space 1S.

[0077] The communication unit 9 has a first communication unit 91 and a second communication unit 92 with different communication distances (communication standards). Note that the container-specific information C3 stored in the storage unit 7 can be input into the storage unit 7 of the remaining amount estimation device 100 via the first communication unit 91 or the second communication unit 92.

[0078] The first communication unit 91 can communicate in accordance with a long-distance wireless standard. The first communication unit 91 is composed of a communication device that complies with the long-distance wireless standard. In the present embodiment, the first communication unit 91 is composed of a communication device that complies with LPWA (Low Power Wide Area). Note that the first communication unit 91 may be a communication device that complies with 5G, LTE, or the like.

[0079] The first communication unit 91 is configured to be able to transmit the remaining amount result information C5 estimated by the remaining amount estimation unit 8 to the first external device 201 described with reference to FIG. 1. That is, the first external device 201 is configured to be able to receive the remaining amount result information C5 output from the remaining amount estimation unit 8. The first external device 201 has a first external communication unit (not shown) capable of communicating according to the same communication standard as the first communication unit 91, and can communicate with the first communication unit 91 in accordance with a long-distance wireless standard. Thereby, the remaining amount Ra of the container T output from the remaining amount estimation device 100 can be remotely monitored. By monitoring the remaining amount Ra, it becomes possible to replenish the container T with the contents C at an appropriate timing by the replenishment service system of the contents C.

[0080] The second communication unit 92 is capable of communicating in accordance with a short-distance wireless standard. The second communication unit 92 is composed of a communication device that complies with a short-distance wireless standard. In the present embodiment, the second communication unit 92 is composed of a communication device that complies with BLE (Bluetooth Low Energy). Note that the second communication unit 92 may be a device that complies with Bluetooth (registered trademark), WiFi, Private LoRa, Z-Wave, ZigBee (registered trademark), Thread, Matter, etc. other than BLE.

[0081] The second communication unit 92 receives control data for the remaining amount estimation device 100 (control unit 5) from the second external device 202 described with reference to FIG. 1. That is, the second external device 202 is configured to be able to transmit control data for the remaining amount estimation device 100. The second external device 202 has a second external communication unit (not shown) capable of communicating according to the same communication standard as the second communication unit 92, and can communicate with the second communication unit 92 in accordance with a short-distance wireless standard (for example, wireless communication between the remaining amount estimation device 100 and P to P).

[0082] [Remaining amount estimation process] Next, with reference to FIG. 8, the remaining amount estimation process (remaining amount estimation method) by the remaining amount estimation unit 8 will be described. FIG. 8 is a flowchart showing the remaining amount estimation process. The remaining amount estimation process is executed, for example, at a preset (scheduled) frequency (for example, at one-hour intervals). However, the remaining amount estimation process may be executed in response to an instruction from an operator who estimates the remaining amount Ra of the contained substance C.

[0083] When execution is instructed at a preset timing or by an operator, as shown in FIG. 8, the sensor unit 6 measures the distance to the reflecting surface by transmitting radio waves from the transmitting unit, receives the radio waves, and outputs measurement result information C2 (step S101). When the remaining amount estimation unit 8 acquires the measurement result information C2 from the sensor unit 6 (step S103), it determines whether the measurement result information C2 includes second measurement result information C22 other than the first measurement result information C21 (step S105). That is, the remaining amount estimation unit 8 determines whether the measurement distance ds indicated by the measurement result information C2 exceeds the upper limit of the first allowable range R1 and is less than or equal to the upper limit of the second allowable range R2.

[0084] When the remaining amount estimation unit 8 determines that the measurement result information C2 does not include the second measurement result information C22 (the measurement distance ds is less than or equal to the upper limit of the first allowable range R1 or exceeds the upper limit of the second allowable range R2) (step S105; No), it estimates that the remaining amount Ra of the contained substance C is full (step S107) and proceeds to step S115.

[0085] On the other hand, when the remaining amount estimation unit 8 determines that the measurement result information C2 includes second measurement result information C22 other than the first measurement result information C21 (the measurement distance ds exceeds the upper limit of the first allowable range R1 and is less than or equal to the upper limit of the second allowable range R2) (step S105; Yes), it determines whether the measurement distance ds is included in the second allowable range R2 (that is, whether it is greater than or equal to the lower limit of the second allowable range R2) (step S109).

[0086] When the remaining amount estimation unit 8 determines that the measured distance ds is included in the second allowable range R2 (step S109; Yes), it estimates that the remaining amount Ra is empty (remaining amount Ra is "0") (step S111), and proceeds to step S115.

[0087] On the other hand, when the remaining amount estimation unit 8 determines that the measured distance ds is not included in the second allowable range R2 (step S109; No), the remaining amount estimation unit 8 obtains the remaining amount Ra of the contained substance C by calculating based on the measurement result information C2 estimated by the sensor unit 6 and the measurement result information C2 stored in the storage unit 7 (step S113), and proceeds to step S115.

[0088] For example, when the value indicated by the container specific information C3 (the bottom surface distance dt between the sensor unit 6 and the bottom surface T11) is "100 cm" and the contained substance distance df between the sensor unit 6 and the contained substance C with a relative dielectric constant εr of "2" is "50 cm", the depth dc (actual distance) of the contained substance C is obtained as 100 - 50 (50×√1) = 50 cm. The remaining amount estimation unit 8 obtains the remaining amount Ra of the contained substance C based on the obtained depth dc (actual distance) of the contained substance C and the estimation related information C4. For example, as shown by the graph in FIG. 7, when the depth dc (actual distance) of the contained substance C is "50 cm", the remaining amount estimation unit 8 obtains the remaining amount Ra of the contained substance C as "100 L". Note that the remaining amount estimation unit 8 may obtain the remaining amount Ra using values within the second allowable range R2 (values shifted to the lower side Z1 or the upper side Z2).

[0089] Next, in step S115, the remaining amount estimation unit 8 outputs the remaining amount result information C5 indicating the remaining amount Ra of the contained substance C. In the present embodiment, the remaining amount result information C5 is transmitted to the first external device 201 via the first communication unit 91. Thereby, the remaining amount estimation process ends.

[0090] [Effects of the Embodiment] The remaining amount estimation device 100 configured as described above has the following effects.

[0091] (1) According to the above embodiment, the measurement distance ds that is equal to or less than the upper limit of the first allowable range R1 preset according to the specifications of the sensor unit 6 (a region that cannot be accurately measured due to the sensitivity characteristics of the sensor unit 6, etc.) and the specifications of the container T (regions that cannot be accurately measured due to specifications such as the size of the container T (especially the opening T2) and the shape of the container T (especially the opening T2)) is not used for estimating the remaining amount Ra. Therefore, the remaining amount Ra of the contained substance C can be estimated more accurately.

[0092] (2) When there is a remaining amount Ra of the contained substance C whose relative permittivity εr is large with respect to air, the measurement distance ds to the bottom surface T11 indicated by the measurement result information C2 output from the sensor unit 6 becomes larger than the actual bottom surface distance dt, and a value exceeding the upper limit of the second allowable range R2 is output as the measurement distance ds. By utilizing such a phenomenon, when the measurement distance ds exceeds the upper limit of the second allowable range R2 preset based on the bottom surface distance dt, the remaining amount Ra of the contained substance C can be determined as the full amount, and the remaining amount Ra of the contained substance C can be estimated more accurately.

[0093] (3) Even when the reflected wave reflected by the bottom surface T11 is attenuated and not received by the sensor unit 6 or not detected (determined to be received) by the sensor unit 6 depending on the size and type of the contained substance C, the remaining amount Ra of the contained substance C can be determined as the full amount, and the remaining amount Ra of the contained substance C can be estimated more accurately.

[0094] (4) According to the above embodiment, by determining whether the measurement distance ds is included in the second allowable range R2 preset based on the bottom surface distance dt indicating the distance between the sensor unit 6 and the bottom surface T11 of the container T, the remaining amount Ra can be estimated as empty, and the remaining amount Ra of the contained substance C can be estimated more accurately. Moreover, by adjusting the second allowable range R2, it is possible to estimate (regard) the remaining amount Ra as empty when it is small. Alternatively, by adjusting the first allowable range R1, it is possible to estimate (regard) it as the full amount even when there is a margin with respect to the storage capacity.

[0095] (5) According to the above embodiment, since the remaining amount Ra of the contained substance C is obtained by calculation when the contained substance C is not full and not empty, the remaining amount Ra of the contained substance C can be estimated more accurately.

[0096] (6) According to the above embodiment, since the value actually measured and acquired by the sensor unit 6 attached to the container T can be set as the bottom surface distance dt, the remaining amount Ra of the contained substance C can be estimated more accurately. Also, it becomes possible to distinguish between the second measurement result information C22 and the third measurement result information C23.

[0097] (7) According to the above embodiment, since the bottom surface distance dt can be set based on the specifications of the container T such as catalog values, the work (command creation) for attaching the sensor unit 6 to the container T and acquiring (measuring) the bottom surface distance dt becomes unnecessary, and the complication of the work can be avoided.

[0098] (8) According to the above embodiment, for example, the work (command creation) for executing communication for acquiring the container-specific information C3 between the external device (for example, the first external device 201) that stores the container-specific information C3 becomes unnecessary, and the responsiveness of the sensor unit 6 can be enhanced.

[0099] (9) According to the above embodiment, for example, the work (command creation) for attaching the sensor unit 6 to the container T and acquiring (measuring) the bottom surface distance dt becomes unnecessary, and the complication of the work can be avoided. Also, in any of the manufacturing process of the remaining amount estimation device 100, at the time of shipment, after shipment, and after attachment to the container T, etc., the container-specific information C3 can be stored in the storage unit 7 via the communication unit 9 without requiring the disassembly of the remaining amount estimation device 100.

[0100] (10) According to the above embodiment, the remaining amount Ra of various organic substances can be estimated as the contained substance C. Note that since millimeter waves are absorbed by water and water vapor, millimeter waves that are transmitted into the water without being reflected by the water surface are absorbed by the water. Therefore, when the sensor unit 6 is a millimeter wave sensor, the sensor unit 6 cannot receive the reflected wave having the bottom surface T11 as the reflection surface and cannot output the measurement distance ds. Further, since oxygen absorbs millimeter waves in the vicinity of 60 GHz, when the frequency of the radio wave of the millimeter wave sensor to be used is in the vicinity of 60 GHz, it is affected in the same manner as water and water vapor. However, if the contained substance C is an organic substance, the sensor unit 6 can output the measurement distance ds.

[0101] [Other Embodiments] (1) In the above embodiment, the remaining amount estimation device 100 includes the control unit 5, the storage unit 7, the remaining amount estimation unit 8, and the communication unit 9. However, the storage unit 7 and the remaining amount estimation unit 8 may be provided in a device different from the remaining amount estimation device 100 (for example, a first external device 201 different from the remaining amount estimation device 100 among the devices included in the remaining amount estimation system as shown in FIG. 9). The first external device 201 may include an external storage unit 201a capable of storing the container specific information C3 and an external remaining amount estimation unit 201b capable of estimating the remaining amount Ra. Note that the storage unit 7 and the remaining amount estimation unit 8 may be provided in both the remaining amount estimation device 100 and the first external device 201. That is, the housing 1 included in the remaining amount estimation device 100 only needs to accommodate at least the lens unit 2, the substrate 3, the sensor unit 6, and the communication unit 9, and the power supply unit 4, the control unit 5, the storage unit 7, and the remaining amount estimation unit 8 may be accommodated in a housing different from the housing 1. Thereby, the configuration of the remaining amount estimation device 100 can be simplified. As a result, the cost required for the remaining amount estimation device 100 can be suppressed.

[0102] (2) In the above embodiment, the case where the housing 1 is configured as a single unit has been described. However, the housing 1 may be composed of a plurality of divided bodies divided into a plurality. Also, the substrate 3 is not limited to one and may be composed of a plurality.

[0103] (3) Also, in the above-described embodiment, the case where the accommodation space 1S is configured to be watertight by applying a sealing material such as an adhesive or grease to the gap between the lid portion T3 and the housing 1 has been described. However, the configuration for making the accommodation space 1S watertight is not particularly limited. For example, the accommodation space 1S may be configured to be watertight by disposing an O-ring between the lid portion T3 and the housing 1. Alternatively, the lid portion T3 and the housing 1 may be ultrasonically welded to configure it to be watertight. Further, as a part of the lid portion T3, a member that allows gas to permeate and does not allow liquid to permeate may be used. Also, the housing 1 may be dustproof or explosion-proof. That is, the housing 1 may be configured to be waterproof, dustproof, explosion-proof, etc. by injecting a sealing material such as a potting material.

[0104] (4) A waterproof connector (not shown) may be assembled to the housing 1 described in the above embodiment. Thereby, it becomes possible to dispose the antenna outside the housing 1 by connecting the antenna to the connector. Alternatively, it becomes possible to dispose the battery unit 42 outside the housing 1 by connecting the battery unit 42 to the connector. Thereby, it becomes possible to dispose the components that occupy a large volume outside the housing 1. That is, by assembling a waterproof connector to the housing 1, it is possible to reduce the size of the remaining amount estimation device 100 while maintaining the watertightness of the accommodation space 1S of the housing 1.

[0105] (5) In the above-described embodiment, the case where the contained substance C is kerosene has been described. However, the contained substance C is not limited to kerosene, and any substance having a relative dielectric constant εr of air "substantially 1" or more (preferably "2" or more) and capable of being contained in the container T may be used. For example, it may be an organic substance (organic solvent). Also, the contained substance C is not limited to a liquid, and may be a solid or a mixture of a liquid and a solid. However, it is preferable that the contained substance C does not contain air. Note that the container T is appropriately changed according to the contained substance C to be contained.

[0106] (6) In the above embodiment, the first allowable range R1 is set to straddle the first division line L1, but the first allowable range R1 may not be set to straddle the first division line L1 (it may be only one of the upper side Z2 (sensor unit 6 side) and the lower side Z1 (bottom surface T11 side)). The same applies to the second allowable range R2.

[0107] (7) In the above embodiment, the first allowable range R1 is set for the first division line L1, but the first allowable range R1 may not be set. The same applies to the second allowable range R2.

Industrial Applicability

[0108] The present invention can be used in a remaining amount estimation device.

Explanation of Signs

[0109] 6: Sensor unit 7: Storage unit 8: Remaining amount estimation unit 9: Communication unit (input unit) 200: Remaining amount estimation system C: Contents C2: Measurement result information C3: Container-specific information R2: Second allowable range (allowable range) Ra: Remaining amount T: Container T11: Bottom surface ds: Measurement distance dt: Bottom surface distance

Claims

1. A remaining amount estimation system attached to a container containing a content for estimating a remaining amount of the content, a sensor unit that measures a distance to the content by measuring a time until a transmitted radio wave is reflected from a surface of the content and received, and outputs measurement result information indicating the measured distance; a remaining amount estimation unit that estimates the remaining amount based on the measurement result information, wherein the remaining amount estimation unit estimates the remaining amount without using a measurement distance equal to or less than a first allowable threshold value preset according to specifications of the sensor unit and / or the container among the measurement distances indicated by the measurement result information.

2. The remaining amount estimation unit determines whether or not the measurement distance exceeds a second allowable threshold value preset based on a bottom surface distance indicating a distance between the sensor unit and a bottom surface of the container, and when it is determined that the measurement distance exceeds the second allowable threshold value, estimates that the remaining amount of the content is full. The remaining amount estimation system according to claim 1.

3. The remaining amount estimation unit estimates that the remaining amount of the content is full when it is determined that the measurement distance is equal to or less than the first allowable threshold value. The remaining amount estimation system according to claim 1.

4. When the remaining amount estimation unit determines that the measurement distance is equal to or less than the second allowable threshold value, determines whether or not the measurement distance is included in a preset allowable range with respect to the bottom surface distance, and when it is determined that the measurement distance is included in the allowable range, estimates that the remaining amount is empty. The remaining amount estimation system according to claim 2.

5. When the remaining amount estimation unit determines that the measurement distance is not included in the allowable range, it estimates the remaining amount based on the measurement distance. The remaining amount estimation system according to claim 4.

6. The residual amount estimation system according to claim 2, wherein the bottom surface distance is the measurement result information obtained by the sensor unit in a state where the container is not filled with the contents.

7. The residual amount estimation system according to claim 2, wherein the bottom surface distance is container-specific information based on the specifications of the container.

8. The residual amount estimation system according to claim 7, further comprising a storage unit capable of storing the container-specific information.

9. The residual amount estimation system according to claim 8, further comprising an input unit capable of inputting the container-specific information.

10. The residual amount estimation system according to claim 1 or 2, wherein the contents are organic substances.

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