Dryness detection device, dryness detection method, and dryness detection program

Abstract

To enable a dry state to be recognized in a non-contact manner while minimizing influence of a use environment.SOLUTION: A dryness detection device includes an infrared array sensor 2 for imaging a space in which a dry object is arranged, thermal image data conversion means 24 for converting a signal of each pixel obtained by the infrared array sensor 2 into thermal image data of temperature of a required gradation, background thermal image holding means 25 for imaging the space when the dry object does not exist, and holding obtained background thermal image data, differential thermal image data acquisition means 26 for imaging the space when the dry object is arranged, and acquiring the difference between the obtained thermal image data with the existence of the object and the background thermal image data, and dryness determination means 27 for determining the dryness of the dry object on the basis of the secular change of the differential thermal image data acquired by the differential thermal image data acquisition means 26.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a dryness detection device, a dryness detection method, and a dryness detection program. [Background technology]

[0002] A conventional technique for measuring dryness using an infrared sensor based on the relative temperature difference caused by the heat of vaporization is known. However, this method involves noise from ambient temperature information depending on the location and surrounding environment, making it difficult to identify the object to be detected for dryness, and requiring the processing of large amounts of complex image information.

[0003] Patent Document 1 discloses a system for improving the accuracy of detecting people. The detection device described in this document includes a storage device that stores a background thermal image of a space and a processing device that detects the presence or absence of a person in the space. The processing device creates a current thermal image based on current temperature information of the space, and a differential thermal image including a differential temperature, which is the difference between the current temperature in the current thermal image and the background temperature in the background thermal image. Furthermore, the processing device creates a scatter diagram in which points corresponding to the background temperature and the differential temperature are plotted, with one of the horizontal and vertical axes representing the background temperature and the other representing the differential temperature. A threshold is determined based on the scatter diagram, and the differential temperature is compared with the threshold to detect the presence or absence of a person.

[0004] Patent Document 2 discloses a new type of electric fan, stating that conventional electric fans do not provide sufficient improvement in drying efficiency, take a long drying time, which may cause increased costs, and that in order to blow air directly onto the entire laundry, it is necessary to devise a position for hanging the laundry, which is time-consuming.The electric fan described in Patent Document 2 is equipped with a fan body and a temperature detection means provided on the fan body, and is configured to blow air toward the items to be dried based on the temperature detection result of the temperature detection means.

[0005] Patent Document 3 discloses an image processing device, an image processing method, and a program that can appropriately process thermal imaging data captured by an infrared camera. This image processing device includes a thermal imaging data acquisition unit that acquires thermal imaging data captured by the infrared camera, a correction unit that generates shutterless corrected image data by correcting first thermal imaging data captured by the infrared camera with the shutter closed based on the ambient temperature of the environment in which the infrared camera is used and previously acquired calibration data, a noise component extraction unit that extracts noise components that change over time based on the shutterless corrected image data, and a noise removal unit that removes noise components from second thermal imaging data captured by the infrared camera with the shutter open.

[0006] Patent Document 4 discloses a clothes dryer. The disclosed clothes dryer has a cylinder, a heater, a motor, a temperature sensor, and a controller. The cylinder contains clothes to be dried. The heater heats and sends air into the cylinder. The motor rotates the cylinder. The temperature sensor has an infrared array sensor and a signal processor. The infrared array sensor detects infrared rays emitted by the clothes and outputs a detection signal. The signal processor processes the detection signal to obtain at least one of the temperature distribution uniformity and average temperature of the clothes, and outputs a control signal based on at least one of the temperature distribution uniformity and average temperature of the clothes. The controller determines whether to stop the drying process based on the control signal. The above clothes dryer can automatically stop the drying process to save energy.

[0007] In addition, Patent Documents 5 to 9 disclose various dryness detection devices. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. 2022-176151 [Patent Document 2] Japanese Patent Application Publication No. 2019-085882 [Patent Document 3] Japanese Patent Publication No. 2023-091428 [Patent Document 4] Japanese Patent Application Publication No. 2018-069053 [Patent Document 5] Japanese Patent Application Publication No. 09-145647 [Patent Document 6] Japanese Patent Application Laid-Open No. 2002-275781 [Patent Document 7] Japanese Patent Application Laid-Open No. 2002-273308 [Patent Document 8] Japanese Patent Application Laid-Open No. 2014-206409 [Patent Document 9] Special Publication No. 2019-512386 Summary of the Invention [Problem to be solved by the invention]

[0009] As described above, there are various conventional devices and methods for detecting dryness, but none of them can separate the object to be dried from the environmental background and determine the dryness state in a non-contact manner while minimizing the influence of the usage environment.

[0010] The present invention has been made in consideration of the current state of conventional dryness detection devices and methods as described above, and its purpose is to provide a dryness detection device, dryness detection method, and dryness detection program that can separate the object to be dried from the environmental background and determine the dryness state in a non-contact manner while minimizing the influence of the usage environment. [Means for solving the problem]

[0011] A dryness detection device according to an embodiment of the present invention comprises a sensor for capturing an image of a space in which an object to be dried is placed, a thermal image data conversion means for converting a pixel-by-pixel signal obtained by the sensor into thermal image data of a required temperature gradation, a background thermal image storage means for capturing an image of the space when an object to be dried is not present and storing background thermal image data obtained by the thermal image data conversion means, a differential thermal image data acquisition means for capturing an image of the space when an object to be dried is placed and calculating the difference between the thermal image data when an object is present obtained by the thermal image data conversion means and the background thermal image data stored by the background thermal image storage means, and a dryness determination means for determining whether the object to be dried is dry based on the change over time in the differential thermal image data obtained by the differential thermal image data acquisition means. A dryness detection device, comprising: The dryness determining means obtains in advance the thermal imaging data of the object to be dried when the object to be dried is no longer affected by the heat of vaporization and reaches a constant temperature, detects pixels constituting the differential thermal imaging data obtained by the differential thermal imaging data obtaining means having a difference value equal to or greater than the value of the thermal imaging data during drying, and calculates the number of pixels having a value equal to or greater than the value of the thermal imaging data as the number of pixels in the dry state, and determines that drying is complete when the number of pixels in the dry state is equal to or greater than a predetermined number. It is characterized by:

[0012] In the dryness detection device according to the embodiment of the present invention, a drying object area designation unit is provided for designating and inputting an area of ​​the object to be dried in the space, and the differential thermal image data acquisition unit determines the difference by inputting the area designated by the drying object area designation unit. Find the difference It is characterized by:

[0016] In the dryness detection device according to an embodiment of the present invention, the background thermal image storage means updates the stored background thermal image data at predetermined intervals after the dryness determination means starts making a determination.

[0017] The dryness detecting device according to the embodiment of the present invention is characterized by comprising a gradation instruction input unit for changing the required gradation used in the conversion performed by the thermal image data converting means. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a diagram illustrating the configuration of a dryness detection device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing the configuration of the dryness detection device of FIG. 1 configured using a computer. [Figure 3]2 is a diagram showing each means of a program that realizes the dryness detection device according to the embodiment of the present invention. FIG. [Figure 4] FIG. 2 is a diagram showing an image of converting a signal obtained by an infrared array sensor used in the dryness detection device according to the embodiment of the present invention into thermal image data. [Figure 5] 4 is a flowchart showing the operation of the dryness detection device according to the embodiment of the present invention. [Figure 6] FIG. 10 is a diagram showing an image of thermal imaging data obtained by capturing an image of a space without an object to be dried. [Figure 7] FIG. 10 is a diagram showing an image of an image obtained by capturing an image of a space in which an object to be dried is placed and acquiring thermal imaging data. [Figure 8] FIG. 8 is a diagram showing an image of the difference result between the thermal imaging data of FIG. 6 and the thermal imaging data of FIG. 7. [Figure 9] 10 is a flowchart showing the operation of a modified example of the dryness detection device according to the embodiment of the present invention. [Figure 10] 10A and 10B are diagrams illustrating the results of specifying and inputting the area of ​​the object to be dried in space. DETAILED DESCRIPTION OF THE INVENTION

[0019] A dryness detection device, a dryness detection method, and a dryness detection program according to an embodiment of the present invention will be described below with reference to the accompanying drawings. In each drawing, the same components are designated by the same reference numerals, and redundant description will be omitted. FIG. 1 shows a block diagram of a dryness detection device according to an embodiment of the present invention. The dryness detection device according to an embodiment of the present invention has a configuration in which an infrared array sensor 2, a display device 3, and an input device 4 are connected to a controller 1. The infrared array sensor 2 captures images of the space in which the objects to be dried are placed. In this embodiment, the infrared array sensor 2 is described, but this infrared array sensor includes any sensor that captures images of the space in which the objects to be dried are placed and can convert the pixel-by-pixel signals obtained by this sensor into thermal imaging data with a required temperature gradation.

[0020] In this embodiment, the controller 1 is configured by a computer such as a microcomputer, and its configuration is as shown in Fig. 2. That is, it constitutes a dryness detection device in which a CPU 10 operates using programs and data in a main memory 11. An external storage interface 13, an input interface 14, a display interface 15, and a data input interface 16 are connected to the CPU 10 via a bus 12.

[0021] An external storage device 23 is connected to the external memory interface 13. The external storage device 23 stores programs and data for the operation of this system, which can be read out and used by the CPU 10 in the main memory 11 as needed. For this reason, as shown in Fig. 3, the external storage device 23 stores programs for implementing a thermal image data conversion means 24, a background thermal image storage means 25, a differential thermal image data acquisition means 26, and a dryness determination means 27. An input device 4 such as a keyboard or touch panel and a pointing device 22 such as a mouse are connected to the input interface 14. A display device 3 having a screen such as an LCD is connected to the display interface 15. An infrared array sensor 2 is connected to the data input interface 16.

[0022] The thermal image data conversion means 24 shown in Fig. 3 converts the signal for each pixel obtained by the infrared array sensor 2 into thermal image data of temperature with a required gradation. The infrared array sensor 2 has, for example, M (positive integer) rows and N (positive integer) columns of infrared photoelectric conversion elements (pixels), and outputs signals (e.g., voltages) reflecting the temperatures corresponding to the M rows and N columns of pixels as shown in Fig. 4. Correspondingly, the thermal image data conversion means 24 converts the voltages into thermal image data of temperature with a required gradation. Here, the thermal image data is expressed in L (positive integer) gradations corresponding to wavelengths from blue to red, and the L gradations can be expressed in k bits.

[0023] Next, the functions of the background thermal image storage means 25, the differential thermal image data acquisition means 26 and the dryness determination means 27 will be described. The background thermal image storage means 25 captures an image of the space when there is no object to be dried, and stores the background thermal image data obtained by the thermal image data conversion means 24. The differential thermal image data acquisition means 26 captures an image of the space when there is an object to be dried, and calculates the difference between the thermal image data when the object is present obtained by the thermal image data conversion means 24 and the background thermal image data stored by the background thermal image storage means 25. The dryness determination means 27 determines whether the object to be dried is dry based on the change over time in the differential thermal image data obtained by the differential thermal image data acquisition means 26.

[0024] The dryness detection device configured as described above operates in accordance with a program corresponding to the flowchart shown in Figure 5. The operation will be described below with reference to this flowchart. The process starts with the infrared array sensor 2 capturing an image of a space without an object to be dried, acquiring and storing thermal imaging data (S11). This results in background thermal imaging data being stored. Figure 6 shows an example of an image displayed based on the stored background thermal imaging data. Next, an image of the space with an object to be dried is captured to acquire thermal imaging data with the object present (S12). Figure 7 shows an example of an image displayed based on the thermal imaging data with the object present acquired in step S12.

[0025] Next, the difference between the thermal imaging data when the object is present acquired in step S12 and the background thermal imaging data stored in step S11 is calculated (S13). Figure 8 shows an example of an image displayed based on the difference data. As a result, basically, only the difference thermal imaging data of the part of the object to be dried remains, as shown in Figure 8.

[0026] Following step S13, the thermal imaging data resulting from the difference is filtered using a temperature parameter for determining the heat of vaporization to reveal pixels in the dry state (S14). For example, the thermal imaging data for the drying state corresponding to the time when the heat of vaporization no longer has an effect on the object to be dried and the object reaches a constant temperature is obtained in advance. Then, for the object to be dried (such as ordinary laundry) whose temperature drops due to the heat of vaporization during drying, the number of pixels having a difference value with a gradation equal to or higher than this temperature (the number of pixels in the dry state) is obtained. On the other hand, for the object to be dried (such as concrete) whose temperature rises due to the heat of vaporization during drying, the number of pixels having a difference value with a gradation equal to or lower than this temperature (the number of pixels in the dry state) is obtained.

[0027] Following step S14, it is checked whether the number of pixels in the dry state is equal to or greater than a predetermined number (S15). If the result is NO, the process returns to step S12, and the process relating to the loop of steps S12 to S15 continues. If the result is YES in step S15, a notification is given by, for example, displaying on the display device 3 that the object to be dried has been dried, and the process ends (S16).

[0028] In the above, the dryness determination means 27 filters the thermal imaging data of the difference result using the temperature parameter for determining the heat of vaporization to reveal pixels in the dry state, and determines that drying is complete when the number of pixels in the dry state is equal to or greater than a predetermined number. The dryness determination means 27 may determine that drying is complete when there is no change in the time-series differential thermal imaging data obtained by the differential thermal imaging data acquisition means 26. Alternatively, the dryness determination means 27 may determine that drying is complete when the difference obtained by the differential thermal imaging data acquisition means 26 becomes zero, i.e., when there is no difference from the background temperature.

[0029] The background thermal image storage means 25 may update the stored background thermal image data at predetermined intervals after the dryness determination means 27 starts determining whether the data is dry or not. That is, as shown in the flowchart of Fig. 9, a step S21 for monitoring the time to update the stored background thermal image data may be provided between steps S11 and S12 of the flowchart of Fig. 5, and when the time to update arrives, the process returns to step S11, where the infrared array sensor 2 captures an image of a space without an object to be dried, acquires thermal image data, and stores the image data (S11).

[0030] Furthermore, a drying object area designation unit may be provided for designating and inputting the area of ​​the object to be dried in the space, and the differential thermal image data acquisition means 26 may perform the difference for the area designated and input by the drying object area designation unit when determining the difference. For example, the input device 4 may be a touch panel, and a command for designating and inputting the area of ​​the object to be dried may be touch-input and the area may be designated by touch-input as shown in Fig. 10. In this case, if the area of ​​the pattern picture shown in Fig. 10 is obtained by normal subtraction, accurate dryness determination can be performed when a wider (or narrower) area is actually the object to be dried.

[0031] Furthermore, a gradation instruction input unit may be provided to change the required gradation used in the conversion performed by the thermal image data conversion means 24. In the previous embodiment, it was stated that the thermal image data is expressed in L (positive integer) gradations corresponding to wavelengths from blue to red, and that the L gradations can be expressed in k bits. In this case, the value of L can be stored in advance in the thermal image data conversion means 24. Alternatively, for example, the input device 4 can be a keyboard, which serves as a gradation instruction input unit to change the gradation, and a command to change the gradation and the value of L can be input. For example, by increasing the value of L from the default value, it is possible to sense the degree of dryness in more detail and perform accurate dryness detection.

[0032] In the above embodiment, the background thermal image storage means 25 captures an image of the space when there is no object to be dried, stores the obtained background thermal image data, and uses the image data to determine whether the object is dry. However, this is not limiting. That is, the space may be imaged when there is no object to be dried, and the pixel values ​​of the background thermal image data obtained by the thermal image data conversion means 24 may be averaged (flattened) and stored as background thermal image data. Subsequently, the space may be imaged when there is an object to be dried, such as laundry, and the difference between the object-present thermal image data obtained by the thermal image data conversion means 24 and the background thermal image data stored by the background thermal image storage means 25 may be calculated. The dryness of the object to be dried may be determined based on the change over time in the calculated differential thermal image data. That is, once drying is complete, the flattened background thermal image data and the object-present thermal image data obtained by imaging the space when there is an object to be dried become the same and disappear (the difference disappears), thereby enabling dryness detection. [Explanation of symbols]

[0033] 1 Controller 2. Infrared array sensor 3 Display device 4 Input Devices 10 CPU 11 Main Memory 12 Bus 13 External memory interface 14 Input Interface 15 Display Interface 16 Data Input Interface 22 Pointing Device 23 External storage device 24 Thermal image data conversion means 25 Background thermal image retention means 26 Differential thermal image data acquisition means 27 Means for determining dryness

Claims

1. a sensor that captures an image of a space in which the object to be dried is placed; a thermal image data conversion means for converting the signal for each pixel obtained by the sensor into thermal image data of a desired temperature gradation; a background thermal image storage means for capturing an image of the space when there is no object to be dried and storing the background thermal image data obtained by the thermal image data conversion means; a differential thermal image data acquisition means for capturing an image of the space when an object to be dried is placed therein and calculating a difference between the thermal image data when the object is present obtained by the thermal image data conversion means and the background thermal image data stored by the background thermal image storage means; dryness determination means for determining dryness of the object to be dried based on the change over time of the differential thermal image data obtained by the differential thermal image data acquisition means; A dryness detection device comprising: The dryness determination means obtains in advance thermal imaging data of the object to be dried when the object to be dried is no longer affected by the heat of vaporization and has reached a constant temperature, detects pixels whose differential values ​​are equal to or greater than the thermal imaging data of the object to be dried for each pixel constituting the differential thermal imaging data obtained by the differential thermal imaging data acquisition means, and calculates the number of pixels having values ​​equal to or greater than this thermal imaging data as the number of pixels in the dry state, and determines that drying is complete when the number of pixels in the dry state is equal to or greater than a predetermined number.

2. a drying object area designation unit for designating and inputting an area of ​​the object to be dried in the space, 2. The dryness detection device according to claim 1, wherein the differential thermal image data acquisition means calculates the difference for an area designated by the object-to-dry area designation unit when calculating the difference.

3. 2. The dryness detection device according to claim 1, wherein the background thermal image storage means updates the stored background thermal image data at predetermined intervals after the dryness determination means starts making a determination.

4. 2. The dryness detecting device according to claim 1, further comprising a gradation instruction input unit for inputting a change to a required gradation used in the conversion performed by said thermal image data converting means.

5. a thermal image data conversion step of obtaining an image of the space in which the object to be dried is placed using a sensor and converting the signal for each pixel into thermal image data of a temperature with a required gradation; a background thermal image storage step of capturing an image of the space when there is no object to be dried and storing the background thermal image data obtained by the thermal image data conversion step; a differential thermal image data acquisition step of capturing an image of the space when an object to be dried is placed therein and calculating a difference between the thermal image data when the object is present obtained in the thermal image data conversion step and the background thermal image data stored in the background thermal image storage step; a dryness determination step of determining whether the object to be dried is dry or not based on the change over time in the differential thermal imaging data obtained in the differential thermal imaging data acquisition step; A dryness detection method comprising: The dryness determination step includes the steps of: obtaining thermal imaging data of the object to be dried when the object is no longer affected by the heat of vaporization and reaches a constant temperature; detecting pixels having difference values ​​equal to or greater than the thermal imaging data of the object to be dried for each pixel constituting the differential thermal imaging data obtained in the differential thermal imaging data obtaining step; determining the number of pixels having values ​​equal to or greater than the thermal imaging data as the number of pixels in the dry state; and determining completion of drying when the number of pixels in the dry state is equal to or greater than a predetermined number.

6. The dryness detection method according to claim 5, characterized in that the differential thermal image data acquisition step calculates the difference for an area specified by a drying object area specifying unit that specifies and inputs an area of ​​the object to be dried in the space.

7. The dryness detection method described in Claim 5, characterized in that in the background thermal image retention step, the background thermal image data retained is updated every predetermined time after the judgment is started by the dryness judgment step.

8. 6. The dryness detection method according to claim 5, wherein when an instruction is inputted by a gradation instruction input unit, a required gradation used in the conversion performed in said thermal image data conversion step is changed.

9. Computer, a thermal image data conversion means for converting a signal for each pixel obtained by a sensor that captures an image of the space in which the object to be dried is placed into thermal image data of a desired temperature gradation; a background thermal image storage means for capturing an image of the space when there is no object to be dried and storing the background thermal image data obtained by the thermal image data conversion means; a differential thermal image data acquisition means for capturing an image of the space when an object to be dried is placed therein and calculating a difference between the thermal image data when the object is present obtained by the thermal image data conversion means and the background thermal image data stored by the background thermal image storage means; a dryness determination means for determining the dryness of the object to be dried based on the change over time in the differential thermal image data obtained by the differential thermal image data acquisition means; A dryness detection program that functions as The computer is configured to function as the dryness determination means by: obtaining thermal imaging data of the object to be dried in advance when the object to be dried is no longer affected by the heat of vaporization and has reached a constant temperature; detecting pixels whose differential values ​​are equal to or greater than the thermal imaging data of the object to be dried obtained by the differential thermal imaging data obtaining means; determining the number of pixels having a value equal to or greater than the thermal imaging data as the number of pixels in the dry state; and determining that drying is complete when the number of pixels in the dry state is equal to or greater than a predetermined number.

10. A dryness detection program as described in Claim 9, characterized in that the computer, as the differential thermal image data acquisition means, is made to function so that when calculating the difference, the difference is calculated for an area specified by a drying object area specification unit that specifies and inputs the area of ​​the drying object in the space.

11. A program for detecting dryness as described in Claim 9, characterized in that the computer is made to function as the background thermal image holding means to update the background thermal image data held by the computer functioning as the dryness judgment means at predetermined intervals after judgment is started.

12. The dryness detection program according to claim 9, characterized in that when an input is received from a gradation instruction input unit that changes the required gradation, the computer is made to function as the thermal image data conversion means to use the input gradation to convert the signal for each pixel obtained by a sensor that captures an image of the space in which the object to be dried is placed into thermal image data of a temperature of the required gradation.

Images