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

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] Conventionally, there is known a technique for measuring dryness from the relative temperature difference caused by the heat of vaporization using an infrared sensor. However, with this method, the information on the surrounding temperature due to the location and the surrounding environment becomes noise, making the method of identifying the object to be detected for dryness unclear, and it is necessary to process a large amount 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 creates 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 one of the horizontal and vertical axes is the background temperature and the other is the differential temperature, and plots points corresponding to the background temperature and the differential temperature. Based on the scatter diagram, a threshold value is determined, and the differential temperature is compared with the threshold value to detect the presence or absence of a person.

[0004] Patent Document 2 discloses a new type of electric fan, stating that there is a problem that the effect of improving drying efficiency is not sufficient, the drying time is long, and there is a risk of causing an increase in costs, and that in order to blow air directly onto the entire laundry, it is necessary to devise a position for hanging the laundry, etc., 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 capable of appropriately processing 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 an 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 environmental temperature of the environment in which the infrared camera is used and calibration data acquired in advance, 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 air and sends it 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 uniformity of temperature distribution of the clothes and the average temperature, and outputs a control signal based on at least one of the uniformity of temperature distribution of the clothes and the average temperature. The controller decides 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] JP 2019-085882 A [Patent Document 3] JP 2023-091428 A [Patent Document 4] JP 2018-069053 A [Patent Document 5] Japanese Patent Application Publication No. 09-145647 [Patent Document 6] JP 2002-275781 A [Patent Document 7] JP 2002-273308 A [Patent Document 8] JP 2014-206409 A [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 can detect 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 know 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 is characterized in that it comprises a sensor which images a space in which an object to be dried is placed, a thermal image data conversion means which converts the signal for each pixel obtained by the sensor into thermal image data of a required temperature gradation, a background thermal image storage means which images the space when an object to be dried is not present and stores the background thermal image data obtained by the thermal image data conversion means, a differential thermal image data acquisition means which images the space when an object to be dried is placed and determines the 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, and a dryness determination means which 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.

[0012] In the dryness detection device of an embodiment of the present invention, a drying object area designation unit is provided which designates and inputs the area of ​​the object to be dried in the space, and the differential thermal image data acquisition means is characterized in that when determining the difference, it performs the difference for the area designated and input from the drying object area designation unit.

[0013] In the dryness detection device of an embodiment of the present invention, the dryness judgment means filters the thermal image data of the difference result using a temperature parameter for judging the heat of vaporization, to reveal pixels in a dry state, and judges that drying is complete when the number of pixels in a dry state is equal to or greater than a predetermined number.

[0014] In the dryness detection device according to an embodiment of the present invention, the dryness determination means determines that drying is complete when there is no longer any change in the time-series differential thermal imaging data obtained by the differential thermal imaging data acquisition means.

[0015] In the dryness detection device according to the embodiment of the present invention, the dryness determining means determines that drying is complete when the difference obtained by the differential thermal imaging data acquiring means becomes zero.

[0016] In the dryness detection device according to the 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 detection device according to the embodiment of the present invention is characterized by comprising a gradation instruction input unit for changing a required gradation used in the conversion performed by the thermal image data conversion means. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a configuration diagram of a dryness detection device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing the configuration of the dryness detection device in FIG. 1 when configured using a computer. [Diagram 3] FIG. 2 is a diagram showing each unit of a program for implementing the dryness detection device according to the embodiment of the present invention. [Figure 4] FIG. 2 is a diagram showing an image of conversion of a signal obtained by an infrared array sensor used in the dryness detection device according to the embodiment of the present invention into thermal imaging data. [Diagram 5] 4 is a flowchart showing the operation of the dryness detection device according to the embodiment of the present invention. [Figure 6] FIG. 13 is a diagram showing an image of thermal imaging data obtained by imaging a space without an object to be dried. [Figure 7] FIG. 13 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 a difference result between the thermal imaging data of FIG. 6 and the thermal imaging data of FIG. [Figure 9] 10 is a flowchart showing the operation of a modified example of a dryness detection device according to an embodiment of the present invention. [Figure 10] 10A to 10C are diagrams for explaining the results of specifying and inputting the area of ​​the object to be dried in space. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, a dryness detection device, a dryness detection method, and a dryness detection program according to an embodiment of the present invention will be described with reference to the accompanying drawings. In each drawing, the same components are assigned the same reference numerals, and duplicated explanations will be omitted. FIG. 1 shows a configuration 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 an image of a space in which an object to be dried is placed. In this embodiment, the infrared array sensor 2 is described, but this infrared array sensor is a sensor that captures an image of a space in which an object to be dried is placed, and includes all sensors that can convert the signal for each pixel obtained by this sensor into thermal imaging data of 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 configures 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 and used by the CPU 10 in the main memory 11 as appropriate. For this reason, 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, as shown in FIG. 3. An input device 4 such as a keyboard or a 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, infrared photoelectric conversion elements (pixels) of M (positive integer) rows and N (positive integer) columns, and outputs a signal (for example, a voltage) reflecting the temperature corresponding to the pixels of M rows and N columns as shown in Fig. 4. Correspondingly, the thermal image data conversion means 24 converts the voltage 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 images 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 images the space when an object to be dried is placed, and calculates the difference between the thermal image data when an 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 judges 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 above operates according to a program corresponding to the flowchart shown in Fig. 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. Fig. 6 shows an example of an image displayed based on the stored background thermal imaging data. Next, an image of the space is captured with an object to be dried arranged therein, and thermal imaging data when the object is present is obtained (S12). Fig. 7 shows an example of an image displayed based on the thermal imaging data when the object is present obtained 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). An example of an image displayed based on the difference data is shown in Fig. 8. As a result, basically, only the difference thermal imaging data of the part of the object to be dried remains as shown in Fig. 8.

[0026] Following this step S13, the thermal image data of the difference result is filtered using a temperature parameter for judging the heat of vaporization to reveal pixels in the dry state (S14). For example, thermal image data during drying corresponding to the time when the heat of vaporization no longer has an effect on the object to be dried and the temperature becomes constant is obtained in advance. Then, for an object to be dried whose temperature drops due to the heat of vaporization during drying (such as ordinary laundry), 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. Also, for an object to be dried whose temperature rises due to the heat of vaporization during drying (such as concrete), 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 related to the loop of steps S12 to S15 continues. If the result is YES in step S15, a notification is given by displaying the completion of drying of the object to be dried on the display device 3 (S16), and the process ends.

[0028] In the above, the dryness determination means 27 filters the thermal imaging data of the difference result by the temperature parameter for judging the heat of vaporization, and displays pixels in a dry state, and determines completion of drying when the number of pixels in a dry state is equal to or greater than a predetermined number. The dryness determination means 27 may determine completion of drying when there is no change in the time-series difference thermal imaging data obtained by the difference thermal imaging data acquisition means 26. The dryness determination means 27 may also determine completion of drying when the difference obtained by the difference thermal imaging data acquisition means 26 becomes zero, i.e., when it becomes the same temperature as the background.

[0029] The background thermal image storage means 25 may update the background thermal image data stored therein at predetermined intervals after the dryness determination means 27 starts making a determination. That is, as shown in the flow chart of Fig. 9, a step S21 for monitoring the arrival of the time to update the stored background thermal image data may be provided between steps S11 and S12 of the flow chart 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, obtains thermal image data, and stores the image (S11).

[0030] Also, 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 thermogram 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 difference, an accurate dryness judgment can be made when a larger (or smaller) area is the actual object to be dried.

[0031] Furthermore, a gradation instruction input unit for changing the required gradation used in the conversion performed by the thermal image data conversion means 24 may be provided. 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 the L gradations can be expressed in k bits. In this case, the value of L can be stored in the thermal image data conversion means 24 in advance. Instead of this, for example, the input device 4 can be a keyboard, which serves as a gradation instruction input unit for changing the gradation, and a command for changing the gradation and the value of L can be input. For example, the value of L can be made larger than the default value 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 images the space when there is no object to be dried, stores the obtained background thermal image data, and judges whether the object to be dried is dry using the image data, but the present invention is not limited to this. That is, the space is imaged when there is no object to be dried, and the values ​​of each pixel of the background thermal image data obtained by the thermal image data conversion means 24 are averaged (flattened), and the result is stored as background thermal image data. Then, when an object to be dried such as laundry is placed, the space is imaged, and 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 is calculated, and the dryness of the object to be dried is judged based on the change over time of the calculated difference thermal image data. That is, when the drying is completed, the flattened background thermal image data and the thermal image data when the object is present obtained by imaging the space when the object is placed become the same and disappear (the difference disappears), so that dryness detection can be performed. [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 Entry Interface 22 Pointing Device 23 External storage device 24 Thermal image data conversion means 25 Background thermal image retention means 26 Differential thermal imaging data acquisition means 27 Means for determining dryness

Claims

1. A sensor for imaging a space in which an object to be dried is placed; Thermal image data conversion means for converting the signal for each pixel obtained by the sensor into thermal image data of a required gradation temperature; Background thermal image holding means for imaging the space when there is no object to be dried and holding the background thermal image data obtained by the thermal image data conversion means; Differential thermal image data acquisition means for imaging the space when an object to be dried is placed and obtaining the difference between the thermal image data in the presence of the object obtained by the thermal image data conversion means and the background thermal image data held by the background thermal image holding means; Drying determination means for determining the drying 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 drying detection device comprising the above.

2. Comprising a drying object area instruction unit for instructing and inputting the area of the drying object in the space, The differential thermal image data acquisition means performs the difference for the area instructed and input from the drying object area instruction unit when obtaining the difference. The drying detection device according to Claim 1.

3. The drying determination means filters the thermal image data of the difference result by a temperature parameter for latent heat of vaporization determination, exposes the pixels in the drying state, and determines that drying is completed when the number of pixels in the drying state is equal to or more than a predetermined number. The drying detection device according to Claim 1 or 2.

4. The drying determination means determines that drying is completed when there is no change in the time-series differential thermal image data obtained by the differential thermal image data acquisition means. The drying detection device according to Claim 1 or 2.

5. The drying determination means determines that drying is completed when the difference obtained by the differential thermal image data acquisition means becomes zero. The drying detection device according to Claim 1 or 2.

6. The background thermal image holding means updates the background thermal image data held at predetermined time intervals after the determination is started by the drying determination means. The drying detection device according to Claim 1.

7. Comprising a gradation instruction input unit for changing the required gradation used for the conversion performed by the thermal image data conversion means. The drying detection device according to Claim 1.

8. Obtained by a sensor that images the space in which the object to be dried is placed, and a thermal image data conversion step of converting the signal for each pixel into thermal image data of a required gradation temperature; A background thermal image holding step of imaging the space when there is no object to be dried and holding the background thermal image data obtained by the thermal image data conversion step; When the object to be dried is placed, image the space, and obtain the difference between the thermal image data in the presence of the object obtained by the thermal image data conversion step and the background thermal image data held by the background thermal image holding step. A differential thermal image data acquisition step; A drying determination step of determining the drying of the object to be dried based on the change over time of the differential thermal image data obtained by this differential thermal image data acquisition step; A drying detection method characterized by comprising the above.

9. The differential thermal image data acquisition step is characterized in that, when obtaining the difference, the difference is calculated for the area indicated by the object to be dried area indicating unit that instructs and inputs the area of the object to be dried in the space. The drying detection method according to claim 8.

10. In the drying determination step, filtering is performed on the thermal image data of the difference result by a temperature parameter for latent heat of vaporization determination to expose the pixels in the drying state, and when the number of pixels in the drying state is equal to or more than a predetermined number, it is determined that drying is complete. The drying detection method according to claim 8 or 9, characterized in that.

11. In the drying determination step, it is determined that drying is complete when there is no change in the time-series differential thermal image data obtained by the differential thermal image data acquisition step. The drying detection method according to claim 8 or 9, characterized in that.

12. In the drying determination step, it is determined that drying is complete when the difference obtained by the differential thermal image data acquisition step becomes zero. The drying detection method according to claim 8 or 9, characterized in that.

13. In the drying background thermal image holding step, the background thermal image data held at predetermined time intervals after the determination is started by the drying determination step is updated. The drying detection method according to claim 8, characterized in that.

14. When there is an instruction input by the gradation instruction input unit, the required gradation used for the conversion performed by the thermal image data conversion step is changed. The drying detection method according to claim 8, characterized in that.

15. A computer, Thermal image data conversion means for converting the signal for each pixel obtained by a sensor that images the space in which the object to be dried is placed into thermal image data of a required gradation temperature, Background thermal image holding means for imaging the space when there is no object to be dried and holding the background thermal image data obtained by the thermal image data conversion means, Differential thermal image data acquisition means for imaging the space when the object to be dried is placed and obtaining the difference between the thermal image data in the presence of the object obtained by the thermal image data conversion means and the background thermal image data held by the background thermal image holding means, Drying judgment means for making a drying judgment on the object to be dried based on the change over time of the differential thermal image data obtained by this differential thermal image data acquisition means, A drying detection program characterized by being made to function as such.

16. The computer functioning as the differential thermal image data acquisition means is made to function so as to perform the difference for the area indicated by the drying object area instruction unit that instructs and inputs the area of the drying object in the space when obtaining the difference. The drying detection program according to claim 15.

17. The computer functioning as the drying judgment means filters the thermal image data of the difference result by a temperature parameter for latent heat of vaporization, exposes the pixels in the drying state, and when the number of pixels in the drying state is equal to or more than a predetermined number, determines that drying is complete. The drying detection program according to claim 15 or 16.

18. The computer functioning as the drying judgment means determines that drying is complete when there is no change in the time-series differential thermal image data obtained by the computer functioning as the differential thermal image data acquisition means. The drying detection program according to claim 15 or 16.

19. The computer functioning as the drying judgment means is made to function so as to determine that drying is complete when the difference obtained by the computer functioning as the differential thermal image data acquisition means becomes zero. The drying detection program according to claim 15 or 16.

20. The drying detection program according to claim 15, wherein the computer functioning as the background thermal image holding means is caused to function so as to update the background thermal image data held at every predetermined time after the determination is started by the computer functioning as the drying determination means.

21. The drying detection program according to claim 15, wherein when an input is received from the gradation instruction input unit that gives a change to the required gradation, the computer functioning as the thermal image data conversion means uses the input gradation to convert the signal for each pixel obtained by a sensor that images the space in which the object to be dried is arranged into thermal image data of a temperature of the required gradation.

Images