Liquid level sensing system

Abstract

A liquid level sensing system is disclosed for detecting a target container. The liquid level sensing system includes a system body, an optical sensor, a fan unit and a computing processor. The system body has a loading platform for placing the target container. The optical sensor is disposed above the loading platform for generating a detection image covering the target container. The fan unit is disposed in the system body and faces the loading platform. The computing processor is electrically connected to the optical sensor. The computing processor analyzes the detection image generated when the fan unit is running to obtain effective feature points of the target container in the detection image. The liquid level sensing system can preferably set a support plate made of low reflectivity material on the loading platform, and then use the long and short exposure interleaving mechanism of the optical sensor to identify whether the target container belongs to a transparent container or a non-transparent container, and then accurately detect the cup rim and liquid level of the target container according to the cup body characteristics of the target container.

Description

Technical Field

[0001] This invention relates to a liquid level sensing system, and more particularly to a liquid level sensing system that uses optical technology to accurately and quickly detect the liquid level of a target container. Background Technology

[0002] Traditional water dispensers cannot detect the water level or the characteristics of the container. Users must visually inspect the container and manually control the dispenser to avoid spillage. Traditional coffee machines use proximity or ultrasonic sensors to detect if the container is positioned correctly near the spout; however, these sensors cannot detect the container's characteristics, remaining capacity, or liquid level. Therefore, designing a liquid detection device that utilizes optical detection technology to detect the container's remaining capacity, characteristics, and liquid level to enhance the functionality of water dispensers and coffee machines has become a key development goal for the optical detection industry. Summary of the Invention

[0003] This invention relates to a liquid level sensing system that uses optical technology to accurately and quickly detect the liquid level of a target container.

[0004] This invention further discloses a liquid level sensing system for detecting a target container. The liquid level sensing system includes a system body, an optical sensor, a fan unit, and a processing unit. The system body has a platform for placing the target container. The optical sensor is positioned above the platform to generate a detection image covering the target container. The fan unit is mounted on the system body and faces the platform. The processing unit is electrically connected to the optical sensor. The processing unit analyzes the detection image generated when the fan unit operates to obtain valid feature points of the target container from the detection image.

[0005] The present invention also discloses that the liquid level sensing system further includes an illumination source disposed in the main body of the system, which outputs illumination light to the carrying platform.

[0006] The present invention also discloses that the illumination light is projected onto the side of the target container, and the processing unit analyzes the illumination characteristics of the illumination light in the detection image to determine whether the target container is a transparent container or a non-transparent container.

[0007] The present invention also discloses that the liquid level sensing system further includes a fluid output device for injecting fluid into the target container, and the optical sensor is disposed adjacent to the fluid output device in the main body of the system.

[0008] The present invention also discloses that the fan unit generates suction or blowing force to expel gas above the carrying platform.

[0009] The present invention also discloses that the processing unit is further electrically connected to the fan unit, and the fan unit is started or stopped according to the image quality of the detected image.

[0010] The present invention also discloses that the processing unit can adjust the airflow of the fan unit according to the image quality of the detected image.

[0011] The present invention also discloses that the liquid level sensing system further includes a heating unit disposed in the main body of the system, for raising the ambient temperature above the carrying platform.

[0012] The present invention also discloses that the heating unit is an infrared heater, and the wavelength of the heating light signal output by the infrared heater is between 2000 nanometers and 4000 nanometers.

[0013] The present invention also discloses that the liquid level sensing system further includes a protective cover covering the optical sensor, the outer surface of which has an anti-fogging coating.

[0014] This invention also discloses a liquid level sensing system for detecting a target container. The liquid level sensing system includes a system body, a support plate, an optical sensor, and a processing unit. The system body has a carrying platform. The support plate is disposed on the carrying platform. The support plate is made of a low-reflectivity material and is used to hold the target container. The optical sensor is disposed above the carrying platform and is used to generate a detection image covering the target container and the support plate. The processing unit is electrically connected to the optical sensor. The processing unit analyzes the detection image to obtain effective feature points that can distinguish the target container from the support plate.

[0015] The present invention also discloses that the liquid level sensing system further includes an illumination source disposed in the main body of the system, which outputs illumination light to the carrying platform.

[0016] The present invention also discloses that the illumination light is projected onto the side of the target container, and the processing unit analyzes the illumination characteristics of the illumination light in the detection image to determine whether the target container is a transparent container or a non-transparent container.

[0017] The present invention also discloses that the optical sensor generates multiple detection images with different exposure parameters.

[0018] The present invention also discloses that the processing unit compares the image features of the detected image to a feature threshold range, and shortens the exposure parameters of the optical sensor when the image features exceed the feature threshold range, and extends the exposure parameters when the image features are equal to or below the feature threshold range.

[0019] The present invention also discloses that the optical sensor alternately generates a first detection image and a second detection image with a first exposure parameter and a second exposure parameter, and the first exposure parameter of the first detection image is greater than the second exposure parameter of the second detection image.

[0020] The present invention also discloses that the processing unit analyzes the first detection image to find the rim of the target container, and analyzes the second detection image to confirm the liquid level in the target container.

[0021] The present invention also discloses that the processing unit compares the liquid level height with a preset height condition, and adjusts the ratio of the number of the first detection image and the second detection image per unit time according to the comparison result.

[0022] The present invention also discloses that when the processing unit determines that the liquid level height meets the preset height condition, it increases the number of the second detection images within the unit time.

[0023] The present invention also discloses that when the processing unit determines that the liquid level height meets the preset height condition, it generates the second detection image using only the second exposure parameter.

[0024] The liquid level sensing system of this invention can utilize one or both of a fan unit and a heating unit to remove steam above the target container, ensuring that the detection image acquired by the optical sensor is not interfered with and its image quality is not affected. The liquid level sensing system can also selectively provide a protective cover with an anti-fogging coating on the optical sensor to further prevent steam interference with the detection image. Preferably, the liquid level sensing system can be equipped with a support plate made of a low-reflectivity material on the platform, and can use an illumination source to project illumination light onto the side of the target container in a side-projection manner. Combined with the long and short exposure alternation mechanism of the optical sensor, it first identifies whether the target container is transparent or opaque, and then selects the appropriate exposure algorithm based on the characteristics of the target container's body, thus accurately detecting the relevant information of the rim and liquid level height of the target container. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the liquid level sensing system according to the first embodiment of the present invention.

[0026] Figure 2 This is a functional block diagram of the liquid level sensing system according to the first embodiment of the present invention.

[0027] Figure 3 and Figure 4 This is a schematic diagram of the detection images obtained by the liquid level sensing system in different scenarios according to the first embodiment of the present invention.

[0028] Figure 5 and Figure 6This is a schematic diagram of the detection images obtained by the liquid level sensing system of the first embodiment of the present invention in other situations.

[0029] Figure 7 This is a schematic diagram of the liquid level sensing system according to the second embodiment of the present invention.

[0030] Figure 8 This is a functional block diagram of the liquid level sensing system according to the second embodiment of the present invention.

[0031] Figure 9 This is a schematic diagram of the detected image obtained by the liquid level sensing system according to the second embodiment of the present invention.

[0032] Figure 10 and Figure 11 This is a schematic diagram of the detection images obtained by the liquid level sensing system of the second embodiment of the present invention under different exposure parameters.

[0033] The reference numerals in the attached figures are explained as follows:

[0034] 10. Liquid Level Sensing System

[0035] 12 System Main Body

[0036] 14 Optical Sensors

[0037] 16 fan units

[0038] 18 Fluid output device

[0039] 20 processing units

[0040] 22. Passenger Platform

[0041] 24 Target Container

[0042] 26 heating units

[0043] 28 Protective Cover

[0044] 30 Lighting source

[0045] 50 Liquid Level Sensing System

[0046] 52 System Main Body

[0047] 54 Support Plate

[0048] 56 Optical Sensors

[0049] 58 processor

[0050] 60 passenger platform

[0051] 62 Target Container

[0052] 64 Lighting source

[0053] I,I1,I2,I3,I4 Detected Images

[0054] Il First Detection Image

[0055] Is the second detection image Detailed Implementation

[0056] Please see Figures 1 to 4 , Figure 1 This is a schematic diagram of the external appearance of the liquid level sensing system 10 according to the first embodiment of the present invention. Figure 2 This is a functional block diagram of the liquid level sensing system 10 according to the first embodiment of the present invention. Figure 3 and Figure 4 This is a schematic diagram of the detection images obtained by the liquid level sensing system 10 according to the first embodiment of the present invention under different conditions. The liquid level sensing system 10 may include a system body 12, an optical sensor 14, a fan unit 16, a fluid output device 18, and a processing unit 20. The system body 12 may have a carrying platform 22 for placing the target container 24. The optical sensor 14 and the fluid output device 18 may be arranged adjacent to each other on the system body 12 and located above the carrying platform 22. The fan unit 16 may be arranged on the system body 12, and may be located next to or below the optical sensor 14; as long as the fan unit 16 can face the carrying platform 22, it meets the design purpose of the present invention.

[0057] The fluid output device 18 can be used to inject fluid into the target container 24. The optical sensor 14 generates a detection image I covering the target container 24. The processing processor 20 is electrically connected to the optical sensor 14, the fan unit 16, and the fluid output device 18. The processing processor 20 analyzes the detection image I to obtain feature points of the target container 24, thereby determining the liquid level information of the target container 24. However, if the fluid is a high-temperature liquid and the fan unit 16 is not activated, the optical sensor 14 will be affected by hot steam, causing the feature points of the generated detection image I to be blurred and difficult to identify. Therefore, the processing processor 20 can activate the fan unit 16 and analyze the detection image I2 generated by the optical sensor 14 when the fan unit 16 is running, so as to obtain the effective feature points of the target container 24 from the detection image I2 and correctly determine the liquid level height in the target container 24.

[0058] In this invention, the fan unit 16 can selectively generate suction or blowing force to expel the gas above the carrying platform 22, so that the optical sensor 14 can obtain a clear detection image I in an environment free from the interference of hot steam; or, the fan unit 16 may also generate suction and blowing force alternately. As long as the mode can quickly and reliably expel the gas above the carrying platform 22, it is within the design purpose of this invention.

[0059] When the optical sensor 14 generates a detection image I, the processing processor 20 can instantly analyze whether the detection image I belongs to a detection image I1 with blurred feature points or a detection image I2 with clear feature points. If it belongs to a detection image I1 with poor image quality, the processing processor 20 can start the fan unit 16, or further increase the airflow of the fan unit 16 if the fan unit 16 is already started; if it belongs to a detection image I2 with superior image quality, the processing processor 20 can turn off the fan unit 16, or reduce the airflow of the fan unit 16 if the fan unit 16 is already started.

[0060] In addition, the liquid level sensing system 10 can optionally be equipped with a temperature sensor (not shown in the figures) on the main body 12 of the system. The temperature sensor is electrically connected to the processing unit 20 and is located above the platform 22 to detect changes in the ambient temperature caused by the target container 24. If the ambient temperature obtained by the temperature sensor is higher than the preset temperature value, it indicates that the fluid in the target container 24 is a high-temperature liquid, and the processing unit 20 will start the fan unit 16 or increase the fan speed of the fan unit 16; if the ambient temperature obtained by the temperature sensor is equal to or lower than the preset temperature value, the fluid in the target container 24 is not a high-temperature liquid, and the processing unit 20 can turn off the fan unit 16 or reduce the fan speed of the fan unit 16.

[0061] Furthermore, the liquid level sensing system 10 can optionally include a heating unit 26 on the system body 12. The heating unit 26 is electrically connected to the processing unit 20 and is used to increase the ambient temperature above the platform 22. The heating unit 26 is preferably a mid-wave infrared heater, outputting a heating light signal with a wavelength between 2000 nm and 4000 nm, intended to heat the steam and cause it to evaporate and dissipate rapidly. The processing unit 20 can determine whether to activate the heating unit 26 and the energy intensity of the activating heating unit 26 based on one or both of the image quality of the detected image I and the ambient temperature from the temperature sensor. Notably, the processing unit 20 can simultaneously or alternately activate the fan unit 16 and the heating unit 26 to accelerate steam removal; the specific variations depend on the steam diffusion range and the power supply conditions of the liquid level sensing system 10, and therefore, other variations will not be described in detail.

[0062] Generally, the liquid level sensing system 10 preferably utilizes a protective cover 28 to cover the optical sensor 14. The outer surface of the protective cover 28 may have an anti-fogging coating to avoid or reduce interference from steam on the image quality of the detected image I acquired by the optical sensor 14. The anti-fogging coating may be made of highly hydrophilic polycarbonate or polyester material, forming a continuous water film on the optical sensor 14 to prevent irregular scattering of light, thereby improving the clarity of the optical sensor 14. The material of the anti-fogging coating is not limited to the aforementioned embodiment and depends on the design requirements.

[0063] The liquid level sensing system 10 may further include an illumination source 30, disposed on the system body 12 and electrically connected to the processing processor 20. The illumination source 30 is used to output illumination light to the platform 22, thereby improving the image quality and clarity of the detected image I. In other possible variations, the liquid level sensing system 10 may position the illumination source 30 on the side of the system body 12, and the illumination light output by the illumination source 30 may be projected onto the side of the target container 24. Please refer to [link to relevant documentation]. Figure 5 and Figure 6 , Figure 5 and Figure 6 This is a schematic diagram of the detection images obtained by the liquid level sensing system 10 of the first embodiment of the present invention in other scenarios. For example... Figure 5 As shown, if the target container 24 is a non-transparent container, the detection image I3 obtained by the optical sensor 14 will only show illumination features caused by the illumination light on a small portion of the side of the target container 24; as Figure 6 As shown, if the target container 24 is a transparent container, the detection image I4 obtained by the optical sensor 14 can show illumination features in the middle and most sides of the target container 24.

[0064] In other words, the liquid level sensing system 10 can use the illumination source 30 to provide lateral illumination to the target container 24, and then perform image recognition through methods such as reference image comparison or deep learning to determine whether the target container 24 is a transparent or opaque container, thereby selecting a suitable algorithm to correctly obtain the effective feature points of the target container 24 from the detection image I. The liquid level sensing system 10 can be equipped with a single illumination source 30 in the system body 12, serving the purpose of both enhancing the illumination brightness of the target container 24 and classifying and detecting the cup body; alternatively, the liquid level sensing system 10 can also selectively provide two illumination sources 30, used for enhancing the illumination brightness of the target container 24 and classifying and detecting the cup body, respectively.

[0065] Therefore, when the liquid level sensing system 10 acquires the detection image I, it first performs cup classification detection, classifying the illumination features generated by the side illumination light in the detection image I to determine whether the cup characteristics of the target container 24 belong to a non-transparent container or a transparent container. If the target container 24 is a non-transparent container, the corresponding exposure algorithm is applied to calculate the rim height and liquid level of the target container 24 to obtain the liquid level information of the target container 24. This liquid level information can be the ratio of the liquid level height to the rim height, but practical applications are not limited to this. If the target container 24 is a transparent container, it is preferable to first identify the material of the contents, for example, identifying whether the fluid in the target container 24 is a transparent liquid such as water or a non-transparent liquid such as coffee, and then selecting the corresponding exposure algorithm according to the fluid material to calculate the rim height and liquid level of the target container 24 to obtain the liquid level information of the target container 24.

[0066] Please see Figures 7 to 11 , Figure 7 This is a schematic diagram of the external appearance of the liquid level sensing system 50 according to the second embodiment of the present invention. Figure 8 This is a functional block diagram of the liquid level sensing system 50 according to the second embodiment of the present invention. Figure 9 This is a schematic diagram of the detection image I obtained by the liquid level sensing system 50 according to the second embodiment of the present invention. Figure 10 and Figure 11 This is a schematic diagram of detection images Il and Is obtained by the liquid level sensing system 50 according to a second embodiment of the present invention under different exposure parameters. The liquid level sensing system 50 may include a system body 52, a support plate 54, an optical sensor 56, and a processing unit 58. The system body 52 may have a carrying platform 60. The support plate 54 may be made of a low-reflectivity material and is disposed on the carrying platform 60 to support the target container 62. The optical sensor 56 may be disposed above the carrying platform 60 to generate detection image I covering the target container 62 and the support plate 54. The processing unit 58 may be electrically connected to the optical sensor 56 to analyze the detection image I to obtain effective feature points in the detection image I that can distinguish the target container 62 and the support plate 54.

[0067] The liquid level sensing system 50 is mainly used to detect the liquid level information of the target container 62 with a transparent body. The platform 60 is typically made of a highly reflective material; if the target container 62 is placed directly on the platform 60, the detection image I obtained by the optical sensor 56 will simultaneously show the reflection characteristics of both the platform 60 and the target container 62. The processing processor 58 has difficulty clearly distinguishing the difference between the two, and therefore cannot obtain the correct liquid level information of the target container 62. Figure 9 As shown, the liquid level sensing system 50 places a support plate 54 made of low reflectivity material on the carrying platform 60 to support the target container 62. Only the target container 62 and the support plate 54 will appear in the detection image I, thus effectively eliminating the interference of high reflectivity of the carrying platform 60, thereby improving the image recognition accuracy of the detection image I.

[0068] In addition, the liquid level sensing system 50 also uses a mechanism of alternating long and short exposures to identify the rim and liquid level of the target container 62 in order to obtain the correct liquid level information of the target container 24. The optical sensor 56 generates multiple detection images I according to different exposure parameters. For example, a first detection image II is generated with a longer first exposure parameter, and a second detection image Is is generated with a shorter second exposure parameter. When the rim and liquid level of the target container 62 are still unknown, the optical sensor 56 will alternately generate the first detection image II and the second detection image Is. If preliminary liquid level information is obtained, but it is uncertain whether the liquid level information will continue to change, the generation ratio of the first detection image II and the second detection image Is obtained by the optical sensor 56 can be adaptively adjusted according to the sensing results, so as to accurately and quickly obtain the continuously changing liquid level information of the target container 24.

[0069] For example, the processing unit 58 can compare the obtained liquid level height with a preset height condition, and then adjust the ratio of the number of the first detection image 1l and the second detection image Is per unit time based on the comparison result. If the liquid level height does not meet or is lower than the preset height condition, it indicates that there is only a small amount of fluid or no fluid in the target container 62. In this case, the optical sensor 56 preferably detects at a frequency where the first detection image 1l and the second detection image Is are generated alternately. If the liquid level height meets or exceeds the preset height condition, it indicates that the fluid in the target container 62 has increased or filled up. In this case, the number of second detection images Is per unit time can be increased to find the continuous change of liquid level information; the first detection image 1l can still be used to detect the edge of the cup to determine whether the position of the target container 62 has changed. It is worth mentioning that if the liquid level height meets or exceeds the preset height condition, the optical sensor 56 can also generate only the second detection image Is to find the subsequent changes of liquid level information.

[0070] Because the target container 62 has a transparent cup body, the optical sensor 56 will increase the exposure parameters of the detection image I. The liquid level sensing system 50 needs to use the first exposure parameters to generate the first detection image Il in order to clearly identify the rim of the target container 62. The rim can be referenced as follows: Figure 10 The area shown is indicated by the dashed line. However, the first detection image II generated by the long exposure parameters will have a reduced resolution due to reflections inside the target container 62. Therefore, the liquid level sensing system 50 will use a second detection image Is generated by the second exposure parameters to clearly identify the liquid level height inside the target container 62. Thus, the liquid level sensing system 50 can utilize the alternating long and short exposure mechanism of the detection images to simultaneously and accurately detect the relevant information of the rim and liquid level height of the target container 62.

[0071] The actual values ​​of the first and second exposure parameters may vary due to ambient brightness, auxiliary lighting, the detection performance of the optical sensor 56, and the algorithm of the processing processor 58, and therefore will not be described in detail here. Specifically, the liquid level sensing system 50 can set two sets of feature threshold ranges and compare the image features of the first detection image Il and the second detection image Is to different feature threshold ranges. Image features may be the brightness of the detected image or other parameters. If the image features exceed the feature threshold range, it indicates that the image brightness is too high, so the exposure parameters of the optical sensor 56 can be automatically shortened to obtain a better quality image; if the image features are equal to or below the feature threshold range, it indicates that the image brightness is too low, and the exposure parameters of the optical sensor 56 will be automatically extended to generate the first detection image Il and the second detection image Is using appropriate exposure parameters, thereby obtaining effective feature points to identify the rim and liquid level of the target container 62.

[0072] In addition, the liquid level sensing system 50 can selectively provide an illumination source 64, which is located in the system body 52 and electrically connected to the processing processor 58. As described in the first embodiment, the illumination source 64 can provide illumination light to the platform 60; in addition to enhancing the illumination brightness of the detection image I, the illumination source 64 can also be used for cup classification detection. After the liquid level sensing system 50 correctly determines that the target container 62 has a transparent cup body using the illumination source 64, it can select the corresponding exposure algorithm and drive the optical sensor 56 to generate the corresponding first detection image I1 and second detection image Is using a long and short exposure alternation mechanism, so as to correctly identify the rim and liquid level height of the target container 62.

[0073] In summary, the liquid level sensing system of the present invention can utilize one or both of the fan unit and the heating unit to remove steam above the target container, ensuring that the detection image acquired by the optical sensor is not interfered with and its image quality is not affected. The liquid level sensing system can also selectively provide a protective cover with an anti-fogging coating on the optical sensor to further prevent steam interference with the detection image. Preferably, the liquid level sensing system can be equipped with a support plate made of a low-reflectivity material on the platform, and can use an illumination source to project illumination light onto the side of the target container in a side-projection manner. Combined with the long and short exposure staggered mechanism of the optical sensor, it first identifies whether the target container is transparent or opaque, and then selects the appropriate exposure algorithm according to the characteristics of the target container's body, thus accurately detecting the relevant information of the rim and liquid level height of the target container.

[0074] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A liquid level sensing system for detecting a target container, characterized in that, The liquid level sensing system includes: The main body of the system has a carrying platform for placing the target container; An optical sensor, positioned above the platform, is used to generate a detection image covering the target container; A fan unit is located in the main body of the system and faces the platform; and The processing unit is electrically connected to the optical sensor. The processing unit analyzes the detection image generated when the fan unit is operating, thereby obtaining the effective feature points of the target container in the detection image.

2. The liquid level sensing system as described in claim 1, characterized in that, The liquid level sensing system further includes an illumination source, which is located in the main body of the system and outputs illumination light to the carrying platform.

3. The liquid level sensing system as described in claim 2, characterized in that, The illumination light is projected onto the side of the target container, and the processing unit analyzes the illumination characteristics of the illumination light in the detected image to determine whether the target container is a transparent container or a non-transparent container.

4. The liquid level sensing system as described in claim 1, characterized in that, The liquid level sensing system further includes a fluid output device for injecting fluid into the target container, and the optical sensor is disposed adjacent to the fluid output device in the main body of the system.

5. The liquid level sensing system as described in claim 1, characterized in that, The fan unit generates suction or blowing force to expel gas above the platform.

6. The liquid level sensing system as described in claim 1, characterized in that, The processor is further electrically connected to the fan unit and starts or stops the fan unit according to the image quality of the detected image.

7. The liquid level sensing system as described in claim 6, characterized in that, The processor also adjusts the fan unit's airflow based on the image quality of the detected image.

8. The liquid level sensing system as described in claim 1, characterized in that, The liquid level sensing system further includes a heating unit, which is located in the main body of the system to increase the ambient temperature above the platform.

9. The liquid level sensing system as described in claim 8, characterized in that, The heating unit is an infrared heater, and the wavelength of the heating light signal output by the infrared heater is between 2000 nanometers and 4000 nanometers.

10. The liquid level sensing system as described in claim 1, characterized in that, The liquid level sensing system further includes a protective cover over the optical sensor, the outer surface of which has an anti-fogging coating.

Images