Method for removing foam using drainage information and washing machine

Abstract

The present invention relates to a method for removing foam by using drainage information and a washing machine, the method for removing foam by using drainage information according to an embodiment of the present invention, comprises the steps of: performing a course in which a function module of a washing machine is set; calculating first drainage information related to drainage during a drainage operation of the function module by a controller of the washing machine; and executing a foam removal logic by using the first drainage information by the controller.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a method for removing foam based on drainage information and a washing machineBACKGROUND ART

[0002] Conventionally, in a washing machine, when detergent is excessively injected during a washing process, there is a problem that the foam remain in the laundry. Accordingly, the washing machine needs to detect the foam and perform an operation of removing residual detergent.

[0003] Therefore, there is a need for a technique for accurately determining whether the detergent remains and thus effectively removing detergent foam based on the determining result.DETAILED DESCRIPTION OF THE INVENTIONTechnical Purpose

[0004] In order to solve the above-described problem, a purpose of the present disclosure is to propose a method for quickly removing the detergent foam in the washing process.

[0005] A purpose of the present disclosure is to propose a method for checking whether foam have been produced using information generated during a drainage process.

[0006] A purpose of the present disclosure is to propose a method for determining an amount of foam based on the information generated during the drainage process and performing foam removal based on the amount of foam.

[0007] Purposes according to the present invention are not limited to the above-mentioned purpose, and other purposes and advantages according to the present invention that are not mentioned may be understood based on following descriptions, and may be more clearly understood based on embodiments according to the present invention. Further, it will be easily understood that the purposes and advantages according to the present invention may be realized using means shown in the claims or combinations thereof.Technical Solution

[0008] A method for removing foam based on drainage information according to an embodiment of the present invention includes performing, by a functional module of a washing machine, a set course; calculating, by a controller of the washing machine, first drainage information related to drainage during a drainage operation of the functional module; and executing, by the controller, a foam removal logic, based on the first drainage information.

[0009] A washing machine for removing foam based on drainage information according to an embodiment of the present invention includes a functional module configured to perform a set course and generate data related to drainage during a drainage operation; and a controller configured to: calculate first drainage information based on data related to drainage during the drainage operation of the functional module; and control execution of a foam removal logic based on the first drainage information.Technical Effect

[0010] In accordance with the present invention, the detergent foam in the washing process may be quickly removed.

[0011] In accordance with the present invention, the foam may be removed based on a checking result of whether the foam have been produced using the information generated during the drainage process.

[0012] In accordance with the present invention, the amount of foam may be determined based on the information generated during the drainage process, and the foam removal may be performed based on the amount of foam

[0013] The effects of the present invention are not limited to the above-described effects, and those skilled in the art may easily derive various effects of the present invention from the configuration of the present invention.BRIEF DESCRIPTION OF DRAWINGS

[0014] FIG. 1 is a diagram illustrating a process of removing foam in a washing machine according to an embodiment of the present invention and a configuration of devices.

[0015] FIG. 2 is a diagram illustrating a configuration of a washing machine according to an embodiment of the present invention.

[0016] FIG. 3 is a diagram illustrating a process of sensing foam in a drainage situation according to an embodiment of the present invention.

[0017] FIG. 4 is a diagram for determining foam generation according to an embodiment of the present invention.

[0018] FIG. 5 is a graph for sensing foam based on a change in a RPM according to an embodiment of the present invention.

[0019] FIG. 6 is a diagram illustrating a change in a RPM according to an embodiment of the present invention.

[0020] FIG. 7 is a diagram showing a change in a water level according to an embodiment of the present invention.

[0021] FIG. 8 is a diagram showing a change in a water level according to another embodiment of the present invention.

[0022] FIG. 9 is a diagram showing a time correlation between water supply and drainage based on an amount of foam according to an embodiment of the present invention.

[0023] FIG. 10 is a diagram illustrating an operation of each sensor or a timer for detecting an amount of foam according to an embodiment of the present invention.

[0024] FIG. 11 is a diagram illustrating an RPM profile of a washing machine corresponding to dehydration according to an embodiment of the present invention.

[0025] FIG. 12 is a diagram illustrating a process of determining foam generation based on washing course information according to an embodiment of the present invention.MODE FOR INVENTION

[0026] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings so that those skilled in the art to which the present disclosure pertains may easily implement the present invention. The present invention may be implemented in several different forms and is not limited to the embodiments described herein.

[0027] In order to clearly describe the present invention, parts irrelevant to the description are omitted, and the same reference numerals refer to the same or similar components throughout the specification. Further, some embodiments of the present invention will be described in detail with reference to the example drawings. In adding reference numerals to the components of each drawing, the same components may be denoted by the same reference numerals as much as possible even though the components are shown in different drawings. In addition, in describing the present invention, upon determination that a detailed description of related known components or functions may obscure the gist of the present disclosure, the detailed description thereof may be omitted.

[0028] In describing the components of the present disclosure, terms such as first, second, A, B, (a), (b) may be used. The terminology is only intended for distinguishing the constituent elements from other constituent elements, and the nature, sequence, order, number, etc. of the corresponding constituent elements are not limited by the terminology. It will be understood that when a first component is referred to as being “connected to”, “joined to” or “coupled to” a second component, the first component may be directly connected to or joined to or coupled to the second component, or one or more intervening components may be present therebetween.

[0029] In addition, in the implementation of the present invention, the component may be subdivided for convenience of description. However, this component may be implemented in one device or module, or one component may be implemented so as to be distributed into a plurality of devices or modules.

[0030] Hereinafter, a method and device for detecting foam in a washing process of a washing machine will be described.

[0031] FIG. 1 is a diagram illustrating a process of removing foam in a washing machine according to an embodiment of the present invention and a configuration of devices.

[0032] A washing machine 100 detects foam and performs an operation for removing the foam in S1. In this case, the washing machine 100 may transmit information on a water level when the foam is detected, washing-related information, etc. to a server 300. The washing machine 100 may transmit information (a start time, an end time, a performance function, a drainage time duration, a drainage rate, etc.) based on each operation and the water level or the drainage to the server 300, and this information is stored in the server 300 in S2.

[0033] In another example, in the process S1, when there is information to be notified to the user in relation to foam removal, the washing machine 100 may store the related information in the washing machine 100. Thereafter, information related to over-injection of detergent may be notified to the user later, after washing is finished, or at a time when the door of the washing machine is opened.

[0034] The server 300 may transmit the information provided from the washing machine 100 to a user terminal 500 as a push message in S3. In this regard, the user terminal 500 is a terminal possessed by a user who owns or uses the washing machine 100, and the user terminal 500 may be linked to the washing machine 100 via the server 300.

[0035] The link manner between the user terminal 500 and the washing machine 100 may be implemented in various ways, such as a manner in which the washing machine 100 provides information for linking with the corresponding user terminal 500, a manner in which the user terminal 500 installs a predetermined application for linking with the washing machine 100. However, the present disclosure is not limited thereto.

[0036] In the configuration of FIG. 1, the washing machine 100 may provide the user with operation information indicating that the foam removal operation has been performed based on a detecting result of the foam due to the over-detergent during the washing process. The over-detergent refers to a case in which the amount of the input detergent is large compared to the amount or weight of the laundry, or a case in which the amount of detergent is large compared to the amount of water. Alternatively, the over-detergent refers to a case in which a large amount of the detergent is injected based on a specific reference set in the washing machine. Alternatively, the over-detergent refers to a case in which the amount of residual detergent exceeds a predetermined reference during the washing process. In the present disclosure, the over-detergent refers to various states in which a large amount of detergent is input compared to a preset reference.

[0037] In addition, information related to the amount of laundry and the amount of detergent, or the change in the water level, the drainage time duration, or the drainage rate may also be transmitted to the server 300 so that the server 300 may accurately detect the foam in the washing machine under the same condition.

[0038] FIG. 2 is a diagram illustrating a configuration of a washing machine according to an embodiment of the present invention. FIG. 2 is a diagram showing components of a washing machine according to an embodiment of the present invention.

[0039] The washing machine 100 includes a functional module 190 for performing washing, rinsing, and spin functions, a controller 150, a washing machine communicator 160, an interface 170, and a memory 180. The functional module 190 includes a washing tub, and includes a motor for controlling the washing tub, and auxiliary devices for supplying and draining water. More specifically, the functional module 190 may include a water level sensor 192, a RPM sensor 194, and a timer 196 in addition to the above-described components.

[0040] The functional module 190 performs washing, rinsing, and dehydration functions. In addition, the water level sensor 192, the RPM sensor 194 and the timer 196 of the functional module 190 may sense information on a water level, a Revolutions Per Minute (RPM) value, a drainage time duration, etc. in relation to the drainage of water in a water supply and drainage process.

[0041] The controller 150 operates the foam removal function of the functional module 190 to remove the foam detected based on the information sensed by the water level sensor 192, the RPM sensor 194, the timer 196, etc. in the operation process of the functional module 190, generates operation information on the operation of the foam removal function, and stores the generated information in the memory 180.

[0042] In particular, the controller 150 may perform various foam removal functions using a washing course, a washing time, a foam generation amount, and corresponding values detected by the water level sensor 192, the RPM sensor 194, the timer 196, etc. The controller 150 may determine whether the foam have been produced based on a combination of the values sensed by the water level sensor 192, the RPM sensor 194, and the timer 196.

[0043] That is, the controller 150 checks the amount of foam generated in the operation process of the functional module. The controller 150 may select one of the plurality of foam removal logics based on the generated foam amount and the course information set in the functional module 190, and control the functional module 190 according to the selected foam removal logic. In this regard, the foam removal logic includes a set of values for a determination criterion for removing the foam, or information on a function of the washing machine to be performed for the foam removal. Alternatively, the foam removal logic includes instructions, programs, software, or the like defining tasks that the controller 150 should perform to remove the foam.

[0044] The washing machine communicator 160 transmits various data (information related to the amount of laundry and the amount of detergent, or a change in the water level, the drainage time duration, or the drainage rate) used to detect the occurrence of the foam, and operation information related to the removal of foam to the server 300 under the control of the controller 150. That is, the washing machine communicator 160 may transmit the operation information related to the foam detection and the execution of the foam removal logic to the server 300.

[0045] The memory 180 stores therein the information related to the operation of the washing machine 100. The memory 180 may maintain the stored information even when electricity is not supplied thereto.

[0046] The interface 170 provides predetermined visual and auditory information to the user, and is a component including a button manipulated by the user to control the washing machine 100.

[0047] FIG. 3 is a diagram illustrating a process of sensing foam in a drainage situation according to an embodiment of the present invention. The washing machine 100 may detect that a change rate in the water level inside the washing machine varies based on the foam generation amount during drainage, and thus, may determine the foam generation amount based on the change rate in the water level.

[0048] When the foam are detected, the washing machine 100 performs the foam removal logic in various ways, such as removing the foam by repeating water supply and drainage, or injecting a fabric softener, and performs dehydration when the foam have been removed until the water level change rate corresponds to that in a case in which the foam is absent.

[0049] The water level sensor 192 detects a change in the water level or the timer 196 detects the drainage time duration in S11. This corresponds to an embodiment in which the water level sensor 192 or the timer 196 of the washing machine 100 calculates the drainage rate, that is, the water level change rate and time in the drainage process in order to check whether a larger amount of foam are generated in the washing machine, and the controller 150 detects the amount of foam generated based on the calculation result.

[0050] Then, the controller 150 checks whether a time duration of change of the water level or a time duration required for the drainage is equal to or greater than a predetermined reference value in S12.

[0051] When there is a larger amount of foam, the foam interrupt the drainage during the drainage process. For this reason, in response to that there is a larger amount of the foam than when there is no foam, it takes a lot of time to complete the drainage. Accordingly, the controller 150 compares an estimated time (estimated drainage time duration) estimated based on the amount of water set in the washing course and the amount of laundry with the drainage time duration (measured drainage time duration) calculated by the timer 196. In response to that a difference therebetween is greater than or equal to a reference value, the controller 150 determines that the foam have been produced.

[0052] In response to that it is detected that there is no foam in S12, that is, the water level change rate (or the drainage rate) corresponds to that in the case in which the foam is absent, the dehydration is performed in S19.

[0053] On the other hand, when the state in which there is a larger amount of foam is detected in S12, that is, when the water level change rate is lower or the drainage time duration is longer than that in when there is no foam, the washing machine 100 starts the foam removal logic in S13. Thereafter, the process of reducing the amount of foam in the washing machine is performed by repeating the water supply and drainage or performing the emergency foam removal logic. This will be described below in more details.

[0054] When the foam removal is required, the controller 150 starts the foam removal logic in S13. The foam removal logic includes a first foam removal logic and a second foam removal logic. The first foam removal logic refers to a logic to remove a larger amount of foam than an amount of foam which the second foam removal logic removes. That is, the first foam removal logic is an emergency foam removal logic, and the second foam removal logic is a general foam removal logic. In addition, the first foam removal logic refers to a logic for removing the foam in a faster manner than the second foam removal logic does.

[0055] The controller 150 checks whether the course currently in progress is a course that should end faster than a standard course should end in S14. When the course currently in progress is a course that should end faster than the standard course should end, it is necessary to quickly remove the foam. Thus, in this course, the controller 150 may operate the emergency foam removal logic in S16. For example, when the functional module 190 performs water supply during the operation of the emergency foam removal logic, the controller 150 may reduce the foam removal time by adding hot water or introducing a fabric softener in S16.

[0056] On the contrary, upon determination that the course currently in progress is not a course that should end faster than the standard course should end (No in S14), the controller 150 checks whether the amount of foam is large in S15. When the amount of foam is large, the operation S16 (emergency foam removal logic, first foam removal logic) is also performed.

[0057] On the other hand, when there is not much foam, the controller 150 operates the general foam removal logic (second foam removal logic) in S17. This corresponds to an embodiment in which the washing machine performs water supply and drainage at least once.

[0058] After performing the foam removal operation of S17 or S16, the controller 150 checks whether the foam removal logic may be terminated in S18. To this end, the controller 150 may calculate the draining information again. That is, in the process of draining the water after supplying the water to remove the foam, the controller 150 may generate the drainage information using values such as a change in the water level, a drainage time duration, a drainage rate, and the RPM, and check whether the foam have been entirely removed based on the generated information.

[0059] The controller 150 checks whether to terminate the foam removal logic based on a checking result of the remaining amount of foam or based on the sensor value calculated by the other functional module 190 in S18. In response to that the foam removal logic is required to be further performed, the controller 150 may repeat the operations S13 to S17.

[0060] The operation S18 is summarized as follows. The foam removal logic refers to a logic in which the controller 150 repeatedly controls the water supply and drainage of the functional module 190. In addition, the controller 150 calculates the drainage information related to the drainage during the drainage operation of the functional module after performing the foam removal logic. The controller 150 determines whether to repeat the foam removal logic based on new drainage information.

[0061] Upon determination to terminate the foam removal logic in the operation S18, the controller 150 performs dehydration in S19. That is, the controller 150 calculates the drainage information related to drainage during the drainage operation of the functional module and determines whether to end the foam removal logic based on the drainage information. In this process, the controller 150 may compare the calculated drainage information with a drainage time duration (one example of the drainage information) of Table 1 to be described later.

[0062] In order to detect whether the foam are generated in FIG. 3, the water level sensor 192 may detect a change in the water level or the timer 196 may measure the drainage time duration. In addition, the foam may be detected depending on whether the RPM of the motor for rotating the washing tub decreases.

[0063] The controller 150 may increase the RPM due to drainage resistance resulting from the foam when the dehydration is performed. The foam generation determination process based on the RPM will be described with reference to FIG. 4.

[0064] The embodiment of FIG. 3 is summarized as follows. The functional module 190 of the washing machine 100 performs a set course. This means that washing is performed according to various courses such as a standard washing course, a wool course, a blanket washing course, and an underwear washing course.

[0065] In addition, the functional module 190 generates data related to drainage (for example, data sensed by sensors) during the drainage operation, and the controller 150 calculates first drainage information using the data. The first drainage information includes data related to a drainage time duration, a drainage rate, or a change in the water level related to the drainage, or the RPM of a motor rotating the washing tub of the functional module 190.

[0066] The controller 150 executes the foam removal logic based on the first drainage information. The foam removal logic includes a process in which the functional module 190 performs water supply or drainage or inputs a fabric softener to remove the foam. The controller 150 may identify that the foam have been produced in the washing tub based on the first drainage information and determine the amount of foam based on the first drainage information. The controller 150 controls the functional module 190 to control execution of the foam removal logic.

[0067] The drainage information may include data obtained by measuring the drainage time duration or the drainage rate by the timer 196 of the functional module 190. Alternatively, the drainage information may include data obtained by measuring the water level change due to the drainage using the water level sensor 192 of the functional module 190.

[0068] Alternatively, the drainage information may include data obtained by measuring the RPM of the motor rotating the washing tub constituting the functional module 190 using the RPM sensor 194 of the functional module 190 during the drainage process.

[0069] In addition, in executing the foam removal logic in S14, in response to that the set course is a course set to be performed in a faster manner than the standard course is performed or the drainage information calculated in the previous process such as S11 is greater than a reference value, the controller 150 may select the emergency foam removal logic (first foam removal logic). In this regard, the reference value may be an expected drainage time duration or rate. Alternatively, the reference value may be a criterion used for determining whether the amount of foam is large or small.

[0070] In an embodiment, reference values corresponding to large / medium / small amounts of the laundry based on various washing courses such as the standard washing / functional clothing washing / underwear washing / blanket washing may be indicated in the Table 1 and may be stored in the memory 180.

[0071] That is, the washing machine 100 may store, in the memory 180 or the like, information (see Table 1) on a set (expected drainage time duration / first reference value / second reference value) composed of the expected drainage time duration and the reference values used for determining whether the foam is generated, on each of the washing course-laundry type. The second reference value may be optionally included in the set. The first reference value is a reference value that may be used to determine whether the foam is generated, and the second reference value is a reference value used for determining whether the amount of the foam is excessive in the event of the foam occurrence.TABLE 1FunctionalStandardclothingUnderwearBlanketwashingwashingwashingwashingLaundry5 mins / 66 mins / 74 mins / 58 mins / 9amount -mins / 8 minsmins / 9 minsmins / 6 minsmins / 11 minslargeLaundry4 mins / 55 mins / 63 mins / 47 mins / 8amount -mins / 7 minsmins / 8 minsmins / 5 minsmins / 10 minsmiddleLaundry3 mins / 44 mins / 52 mins / 36 mins / 7amount -mins / 6 minsmins / 7 minsmins / 4 minsmins / 9 minssmall

[0072] The values of Table 1 may be pre-stored in the memory 180 when the washing machine 100 is manufactured, and the server 500 or the like may transmit the values as data so that the controller 150 may store the data in the memory 180. In addition, the values of Table 1 may be updated in some cases.

[0073] In addition, the controller 150 may check whether the foam amount is excessive in the first drainage information including the actual drainage time duration using the Table 1.

[0074] For example, when the laundry type is the blanket and the laundry amount is “large”, the drainage time duration exceeds the first reference value (9 minutes). In this case, the controller 150 determines that the foam have been produced. In addition, when the drainage time duration exceeds the second reference value (11 minutes), the controller 150 may determine that the foam is excessively generated and may execute the first foam removal logic (emergency foam removal logic).

[0075] In response to that the laundry type is the blanket and the laundry amount is “large”, and the drainage time duration is a value (for example, 10 minutes) between the first reference value and the second reference value, the controller 150 may determine that the foam have been produced and may execute the second foam removal logic (general foam removal logic).

[0076] Similarly, in response to that the standard washing is performed and the laundry amount is “medium”, and the drainage time duration exceeds the first reference value (5 minutes), the controller 150 determines that the foam have been produced. In addition, when the drainage time duration exceeds the second reference value (7 minutes), the controller 150 may determine that the foam are excessively generated and may execute the first foam removal logic (emergency foam removal logic).

[0077] In response to that the standard washing is performed and the laundry amount is “medium” and the drainage time duration is value (for example, 6 minutes) between the first reference value and the second reference value, the controller 150 may determine that the foam have been produced and may execute the second foam removal logic (general foam removal logic).

[0078] The Table 1 as set forth above relates to the drainage time duration. However, the drainage rate, the RPM, the water level, etc. in the drainage process may be applied in the same way as the above manner in which the drainage time duration of the Table 1 is applied.

[0079] The drainage rate may be calculated based on the amount of water discharged per unit time. The RPM may be determined based on the amount of laundry and the washing course. The change in the water level during the drainage may also be calculated based on the change in the water level per unit time.

[0080] In this case, as shown in Table 1, the expected value / the first reference value / the second reference value based on the washing course and the amount of laundry may be stored in the memory 180. The controller 150 may compare the calculated drainage information with the stored values and may determine whether the foam have been produced or whether the foam have been produced excessively, based on the comparing result.

[0081] Alternatively, the controller 150 may generate the drainage information of Table 1 in real time in proportion to the amount of laundry. Thus, a comparison criterion for the drainage information may be generated more precisely than in the three level manner of the large / medium / small, thereby increasing the accuracy at which whether the foam are produced is determined.

[0082] FIG. 4 is a diagram for determining foam generation according to an embodiment of the present invention. The washing tub constituting the functional module 190 may be rotated by the motor. In this regard, when a large amount of foam is generated, the RPM of the motor to rotate the washing tub increases such that the dehydration is delayed.

[0083] The controller 150 may determine whether the dehydration due to the foam generation is delayed based on whether the RPM increases, as shown in the graph of FIG. 4.

[0084] P1, P2, and P3 refer to periods for which the RPM of the motor that rotates the washing tub for the dehydration are measured, respectively. At the end of each period of the spin cycle, the RPM rapidly rises as indicated by 41, 42, 43, and 44. This corresponds to a case in which a large number of foam is generated in the washing tub. Accordingly, when the RPM increases rapidly as described above, the controller 150 may determine that the frictional force increases inside and outside the washing tub, and may determine that the increase in the frictional force is due to the foam generation.

[0085] As the RPM increases, the controller 150 may operate the foam removal logic to remove the foam.

[0086] FIG. 5 is a graph illustrating sensing of foam based on a change in the RPM according to an embodiment of the present invention. The RPM of the motor rotating the washing tub may increase due to the foam generation during the draining process. Accordingly, when the RPM increases at a point of 46, it is determined that the RPM increases due to the foam generation, and in this response, the washing machine 100 performs water supply for the foam removal logic. As a result, the RPM drops to a low level at a point 47. In addition, the washing machine 100 may perform the draining process while maintaining a predetermined RPM and check whether the measured water level has reached a reference value.

[0087] The controller 150 may check whether a large amount of foam is present based on the increase in the RPM of the motor for rotating the washing tub. The controller 150 determines whether a large amount of foam is present based on a slope of a line along which the RPM increases, a time duration for which a first reference RPM has been changed to a second reference RPM, or a slope of a line along which a first reference RPM has been changed to a second reference RPM, the type of the washing course, the amount of laundry, etc.

[0088] In addition, the controller 150 determines whether a large amount of foam is present based on the rate of change in the water level as detected by the water level sensor 192. In particular, the controller 150 may distinguish the first laundry material type through which the water is quickly drained and the second laundry material type through which the water is slowly drained from each other based on the type of the washing course and the amount of the laundry, and may determine the amount of foam based on the rate of change in the water level and based on each of the first and second laundry material types.

[0089] FIG. 6 is a diagram illustrating a change in a RPM according to an embodiment of the present invention.

[0090] The controller 150 may calculate a time duration for which the first reference RPM r1 has been changed to the second reference RPM r2. In this regard, each of r1 and r2 may vary depending on the washing course and the amount of the laundry. For example, the controller 150 may set the value of each of r1 and r2 in the case where the washing course is the blanket washing to be different from the value of each of r1 and r2 in the case where the washing course is the standard washing. The controller 150 calculates the RPM increase rate based on the r1 and r2 values suitable for the washing course and the amount of the laundry.

[0091] In Case1, the time duration for which the first reference RPM r1 has been changed to the second reference RPM r2 is a time duration (t1−t0) from t0 to t1. In Case2, the time duration for which the first reference RPM r1 has been changed to the second reference RPM r2 is a time duration (t2−t0) from t0 to t2. The controller 150 may apply the emergency foam removal logic or the general foam removal logic based on the time duration for which the first reference RPM r1 has been changed to the second reference RPM r2.

[0092] FIG. 7 is a diagram showing a change in a water level according to an embodiment of the present invention.

[0093] The controller 150 may calculate a time duration for which a first reference water level h1 has been changed to a second reference water level h2. In this regard, each of h1 and h2 may vary depending on the washing course and the amount of the laundry. For example, the controller 150 may set the value of each of h1 and h2 in the case where the washing course is the blanket washing to be different from the value of each of h1 and h2 in the case where the washing course is the standard washing. The controller 150 calculates the water level reduction rate based on the h1 and h2 values suitable for the washing course and the laundry amount.

[0094] In Case1, the time duration for which the first reference water level h1 has been changed to the second reference water level h2 is a time duration (t1−t0) from t0 to t1. In Case2, the time duration for which the first reference water level h1 has been changed to the second reference water level h2 is a time duration (t2−t0) from t0 to t2. The controller 150 may apply the emergency foam removal logic or the general foam removal logic based on the time duration for which the first reference water level h1 has been changed to the second reference water level h2.

[0095] According to an embodiment of the present disclosure, the controller 150 may calculate the foam generation amount based on the sensed values of the water level sensor 192 and the RPM sensor 194 during the spin cycle process and the spent time duration as calculated during the spin cycle process. The drainage is performed after washing of the washing machine and before executing the spin cycle. The drainage should be performed until the water level reaches a specific water height (water level in an empty state). In this regard, the rate of change in the water level varies depending on the generated foam amount.

[0096] When there is a larger amount of foam, the drainage rate is low due to the drainage resistance of the foam and the water level is slowly lowered. In this case, the controller 150 may determine that the foam is produced or a larger amount of foam is produced as in case2 of FIG. 7.

[0097] In addition, the controller 150 may determine that a large amount of foam have been produced in response to that the RPM increase rate is high as shown in the case 1 of FIG. 6.

[0098] Conversely, when there is no foam, there is no drainage resistance due to the foam. Thus, the drainage rate is higher than when there is the foam. Thus, the change rate in the water level is higher than when there is a foam. For example, as in the case 1 of FIG. 7, the controller 150 may determine that there is no foam.

[0099] In addition, the controller 150 may determine that a larger amount of foam have been produced in response to that the RPM increase rate is low as shown in the case 2 of FIG. 6. Alternatively, the controller 150 may determine that the foam have been produced in response to that the measured RPM increases to a specific RPM or higher.

[0100] The water level change rate based on the foam generation amount changes in a linear manner, and the controller 150 may determine the foam generation amount inside the washing machine based on the water level change rate changing in the linear manner.

[0101] When there is a larger amount of foam, the washing machine 100 repeats the process of supplying and draining the water to reduce the amount of foam, and attempts to dehydrate the laundry when the water level change rate corresponds to a level in the case in which the foam is absent.

[0102] FIG. 8 is a diagram showing a change in a water level according to another embodiment of the present invention. Unlike FIG. 7, the water level sensor of FIG. 8 measures a distance between a water top surface and a top level of the washing tub. Therefore, as the distance increases, the drained water amount increases.

[0103] The controller 150 may calculate a time duration for which a first reference distance d1 has been changed to a second reference distance d2. In this regard, each of d1 and d2 may vary depending on the washing course and the amount of the laundry. For example, the controller 150 may set the value of each of d1 and d2 in the case where the washing course is the blanket washing to be different from the value of each of d1 and d2 in the case where the washing course is the standard washing. The controller 150 calculates the water level reduction rate based on the d1 and d2 values suitable for the washing course and the laundry amount.

[0104] In Case1, the time duration for which the first reference distance d1 has been changed to the second reference distance d2 is a time duration (t1−t0) from t0 to t1. In Case2, the time duration for which the first reference distance d1 has been changed to the second reference distance d2 is a time duration (t2−t0) from t0 to t2. The controller 150 may apply the emergency foam removal logic or the general foam removal logic based on the time duration for which the first reference distance d1 has been changed to the second reference distance d2.

[0105] FIG. 9 is a diagram showing a time correlation between water supply and drainage based on the amount of foam according to an embodiment of the present invention. The water level graph of FIG. 9 corresponds to the distance of FIG. 8, and means the distance between the top water surface and a top level of the inner space of the washing tub. Therefore, the distance tends to decrease under the water supply and increase under the water drainage. Based on a result of checking the value sensed by the water level sensor while the drainage is performed for P1, it is identified that the distance between the top water surface and a top level of the inner space of the washing tub slowly increases. This means that the water drains slowly.

[0106] Accordingly, the controller 150 calculates the drainage time duration of P1 and determines that there is a larger amount of foam in response to that the calculated time duration until the measured water level reaches a predetermined water level reference exceeds an expected time duration or the increase rate (slope) of the distance is low. In this response, the controller performs the foam removal logic. In this case, the controller 150 may select one of two or more foam removal logic based on the distance increase rate or slope, the amount of laundry, the washing course, etc.

[0107] Thereafter, the controller 150 performs the foam removal by repeatedly performing the water supply and drainage again. When a drainage time duration of P2 is smaller than or equal to the expected time duration or the increase rate (slope) of the distance is high, the controller 150 determines that the foam have been removed, and thus perform the dehydration.

[0108] According to an embodiment of the present disclosure, the amount of foam generated in the drainage process before the washing machine execute the dehydration after the washing is finished may be detected and then the foam may be removed based on the detection result. The controller 150 determines the amount of foam based on the drainage information such as the change rate of the water level, the change in the RPM of the motor rotating the washing tub, and the drainage time duration during the drainage process as described above. In this case, the controller 150 may determine whether the amount of foam is excessive or whether the foam are generated, based on the washing course and the amount (or weight) information of the laundry.

[0109] When it is identified that there is a larger amount of foam, the controller 150 removes the foam by repeating the water supply and drainage process. In the drainage process, the controller 150 newly generates drainage information and applies the new drainage information as a determination criterion for determining the amount of foam or whether the foam generation occurs and periodically checks the amount of residual foam based on the criterion. Upon determination that the foam amount is small or the foam has been removed, the controller 150 may execute the dehydration. Thus, dehydration execution delay and foam overflow as problems caused by the foam may be prevented.

[0110] In an embodiment, the controller 150 may also apply a change in the drainage information to determine whether to remove the foam. For example, it is assumed that the estimated drainage time duration calculated based on the washing course set in the washing machine 100 and the amount of laundry is 10 minutes. In this case, when the actual measured drainage time duration is 13 minutes, the controller 150 determines that the foam have been produced and performs water supply and drainage once.

[0111] When the measured drainage time duration is 10 minutes and 30 seconds in the drainage process after the water supply for foam removal, this time duration is approximate to the calculated drainage expected time duration. Thus, the controller 150 stops the foam removal operation even though the measured drainage time duration slightly exceeds the expected drainage time duration (10 minutes).

[0112] In another embodiment, it is assumed that the estimated drainage time duration calculated based on the washing course set in the washing machine 100 and the amount of laundry is 10 minutes. In this case, when the actual measured drainage time duration is 13 minutes. Thus, when the controller 150 determines that the foam have been produced performs water supply and drainage once. Subsequently, the measured drainage time duration is 12 minutes and 30 seconds. In this case, the controller 150 may determine that the foam are excessively generated and thus the foam removal is not smoothly performed via the water supply and drainage, and thus may inject a fabric softener or hot water to quickly remove the foam.

[0113] FIG. 10 is a diagram illustrating an operation of each of sensors or a timer for detecting an amount of foam according to an embodiment of the present invention. FIG. 10 illustrates an example of drainage information related to drainage.

[0114] The water level sensor 192 together with the timer 196 detects the water level change rate during the drainage, and the controller 150 may check the amount of foam based on the calculated information.

[0115] While the washing machine performs the drainage, there is a larger amount of foam. In this case, the drainage rate varies due to the drainage resistance of the foam. When there is a greater amount of foam, the drainage resistance of the foam is great, so that the drainage rate is low and the water level change rate is low. Conversely, when there is little foam, there is no drainage resistance of the foam, so that the drainage rate is increased and the rate of change in the water level is also increased.

[0116] Since the drainage rate linearly changes based on the amount of foam generated, the water level change rate also linearly changes based on the amount of foam.

[0117] That is, when the water level sensor 192 generates information on the water level or the distance between the top water level and the top level of the inner space of the washing tub, and the timer 196 generates information on the spent or required time, the controller 150 may detect the amount of foam based on the rate of change of the water level and perform the foam removal logic based on the detected amount of foam.

[0118] In addition, the RPM sensor 194 generates RPM information. The principle of determining the amount of foam as described above may be used even at a low RPM at which the laundry adheres to the drum under a centrifugal force. When a load is applied to the rotation of the motor due to the water or the foam discharged from the laundry under centrifugation during acceleration of the motor at a high RPM for the dehydration, the controller 150 stops the motor. In this case, the low RPM is applied so that the laundry is evenly spread inside the drum again. This takes a lot of time.

[0119] However, instead of stopping the motor, the water may be drained out of the laundry while the motor is rotating at the low RPM, such that the laundry is attached to an inner side surface of the drum under the centrifugal force. In this case, when the cause of the motor load is water, the water may be drained and then the motor may be accelerated to a high RPM again, thereby reducing the dehydration time delay due to the motor stop. On the other hand, when the cause of the motor load is the foam, it may be detected whether the amount of foam is large or small, using the water level sensor as described above.

[0120] Therefore, upon determination that there is a larger amount of foam based on a detecting result of the rate of change in the water level during drainage, the foam may be removed by repeating the water supply and drainage. In this case, the controller 150 may check the water level change rate during the drainage, and determine that the foam removal is unnecessary in response to that the water level change rate corresponding to a small foam amount is detected. Thus, the controller controls the washing machine 100 to perform the dehydration.

[0121] As illustrated in FIGS. 4 to 10, in the event of the motor stop or the low-RPM rotation in which the laundry is attached to the inner side surface of the drum under the centrifugal force, the controller 150 may detect the water level change rate during the drainage process and checks the amount of the generated foam, based on the detection result. In addition, while repeating the drainage and water supply processes, the controller 150 may determine an amount by which the foam has been removed, and thus may determine the additional progress or the termination of the foam removal logic, based on the determined amount.

[0122] The controller 150 may determine whether to perform the foam removal operation based on a detecting result of the water level change rate (drainage rate, drainage time duration, etc.) in the drainage process. In addition, in response to that the water level change rate during the drainage reaches a predetermined reference value, the controller determines that the foam have been removed, and executes the dehydration process.

[0123] FIG. 11 is a diagram showing an RPM profile of a washing machine corresponding to dehydration according to an embodiment of the present invention. The period constituting the profile includes a wet laundry distribution section, a water-draining section, and a main dehydration section. The wet laundry distribution section refers to a section for which the laundry rotates at a low speed so as not to be as unbalanced as possible. The draining section refers to the RPM section for which the largest amount of dehydration occurs in the laundry. In this section, for drainage of water, the motor speed is reduced to a low RPM and then accelerated. The main dehydration section refers to a high-speed dehydration section to remove as much water as possible from the laundry.

[0124] The vertical axis represents the RPM band. The wet laundry distribution RPM (RPM for the wet laundry distribution) has a low RPM level. st_RPM is a RPM at which the drainage starts, and may correspond to a specific value. For example, the controller 150 may set the st_RPM to a specific numerical value such as 100 RPM, 108 RPM, or 115 RPM. Alternatively, the controller 150 may set the st_RPM based on the washing course and the amount or weight of the laundry.

[0125] A transient region RS refers to an RPM band including a resonance frequency at which resonance occurs.

[0126] As described above, at a low RPM at which the laundry is attached to the drum under the centrifugal force, the washing machine may drain water while the motor is rotating the washing tub. In this case, when the cause of the motor load is the foam, it may be detected whether the amount of foam is large or small, using the water level sensor, as described above. Accordingly, the controller 150 may determine whether to proceed with the foam removal logic based on the amount of foam determined based on the motor load due to the increase in the RPM and the sensed value by the water level sensor 192.

[0127] FIG. 12 is a diagram illustrating a process of determining foam generation based on washing course information according to an embodiment of the present invention.

[0128] In the process of performing the set course, the controller 150 calculates expected information in relation to drainage in S51. The expected information may include information such as the estimated drainage time duration, the estimated drainage rate, and the estimated drainage water level when no foam is present which may be calculated based on the set course and the amount (or weight) of laundry as shown in the above Table 1.

[0129] The controller 150 may determine whether to execute the foam removal logic based on a comparing result between the drainage information calculated in the actual drainage process and the expected information in S52. When the difference between the expected information and the actual information is large or the drainage information value is equal to or greater than a predetermined reference value (see Table 1), the controller 150 determines that the drainage time duration increases, the drainage rate is low, or the water level is not lowered to a level below a predetermined level due to the foam and thus executes the foam removal logic. Alternatively, the controller 150 may determine whether to execute the foam removal logic based on the RPM value in the drainage process.

[0130] In accordance with an embodiment of the present disclosure, an additional sensor for checking the foam generation amount is not required, and the washing machine 100 may check whether the foam are generated and the foam generation amount based on the information generated during the drainage process.

[0131] In addition, according to an embodiment of the present disclosure, problems such as delay in dehydration execution start due to the foam and overflow of the foam as the problems caused by the foam may be solved. That is, according to an embodiment of the present disclosure, the amount of foam may be reduced using the foam sensing process and the foam removing operation, and thus the problems caused by the foam may be solved.

[0132] In particular, the controller 150 may store information on the appropriate drainage time duration, drainage rate, or drainage RPM based on the washing course and the type or property of the laundry in the memory 180 as shown in the Table 1 and determine whether the foam have been produced based on the stored information in various washing situations.

[0133] An embodiment of the present disclosure in which all the components are combined with each other or operate in combination with each other has been described. However, the present disclosure is not necessarily limited to this embodiment. Within the scope of the purpose of the present disclosure, at least two of all components may be selectively combined with other or may operate in the selectively combined manner with other. Furthermore, each of the components may be implemented as an independent hardware. However, some or all of the components may be selectively combined with each other and thus may be implemented using a computer program with a program module to perform some or all of the functions combined in one or more pieces of hardware. The codes and code segments that constitute the computer program may be easily deduced by a person skilled in the art from the present disclosure. The computer program may be stored in computer readable media and read and executed by a computer, thereby implementing the method of the present disclosure. The storage media for storing the computer program may include storage media including magnetic recording media, optical recording media, and semiconductor recording devices. Additionally, the computer program implementing an embodiment of the present disclosure includes a program module transmitted in real time through an external device.

[0134] Although the embodiments of the present disclosure have been described above, various changes or modifications may be applied thereto at the level of a person skilled in the art. Accordingly, it will be understood that these changes and modifications are included within the scope of the present disclosure unless they are outside the scope of the present disclosure.Reference numeral100: Washing machine300: Server500: User terminal

Claims

1. A method for removing foam based on drainage information, the method comprising:performing, by a functional module of a washing machine, a set course;calculating, by a controller of the washing machine, first drainage information related to drainage during a drainage operation of the functional module; andexecuting, by the controller, a foam removal logic, based on the first drainage information.

2. The method for removing the foam based on the drainage information of claim 1, wherein the first drainage information includes data obtained by a timer of the functional module measuring a drainage time duration or a drainage rate, or data obtained by a water level sensor of the functional module measuring a water level change due to drainage.

3. The method for removing the foam based on the drainage information of claim 1, wherein the first drainage information includes data obtained by a RPM sensor of the functional module measuring a RPM of a motor rotating a washing tub of the functional module in a drainage process.

4. The method for removing the foam based on the drainage information of claim 1, wherein the executing of the foam removal logic includes:calculating, by the controller, expected information related to the drainage during execution of the set course; anddetermining, by the controller, whether to execute the foam removal logic, based on a comparing result of the first drainage information with the expected information.

5. The method for removing the foam based on the drainage information of claim 1, wherein the execution of the foam removal logic includes repeatedly performing, by the controller, water supply and drainage of the functional module,wherein the method further comprises:calculating, by the controller, second drainage information related to drainage during a drainage operation of the functional module after performing the foam removal logic; anddetermining, by the controller, whether to repeat the foam removal logic, based on the second drainage information.

6. The method for removing the foam based on the drainage information of claim 1, wherein the foam removal logic includes a first foam removal logic and a second foam removal logic,wherein the first foam removal logic is configured to remove a larger amount of foam than an amount of foam removed by the second foam removal logic,wherein the executing of the foam removal logic includes:selecting, by the controller, the first foam removal logic in response to that the set course is a course set to be completed faster than a standard course is or when the first drainage information is greater than a reference value.

7. The method for removing the foam based on the drainage information of claim 6, wherein the first foam removal logic is configured such that the washing machine inputs hot water or a fabric softener into a washing space and subsequently performs water supply and drainage at least one time, thereby removing the foam,wherein the second foam removal logic is configured such that the washing machine performs water supply and drainage at least one time, thereby removing the foam.

8. The method for removing the foam based on the drainage information of claim 1, wherein the method further comprises:calculating, by the controller, third drainage information related to drainage during a drainage operation of the functional module;determining, by the controller, whether to terminate the foam removal logic, based on the third drainage information; andupon determination to terminate the foam removal logic, executing, by the controller, a dehydration process.

9. A washing machine for removing foam based on drainage information, the washing machine comprising:a functional module configured to perform a set course and generate data related to drainage during a drainage operation; anda controller configured to:calculate first drainage information based on data related to drainage during the drainage operation of the functional module; andcontrol execution of a foam removal logic based on the first drainage information.

10. The washing machine for removing the foam based on the drainage information of claim 9, wherein the first drainage information includes data obtained by a timer of the functional module measuring a drainage time duration or a drainage rate, or data obtained by a water level sensor of the functional module measuring a water level change due to drainage.

11. The washing machine for removing the foam based on the drainage information of claim 9, wherein the first drainage information includes data obtained by a RPM sensor of the functional module measuring a RPM of a motor rotating a washing tub of the functional module in a drainage process.

12. The washing machine for removing the foam based on the drainage information of claim 9, wherein the controller configured to execute the foam removal logic is further configured to:calculate expected information related to the drainage during execution of the set course; anddetermine whether to execute the foam removal logic, based on a comparing result of the first drainage information with the expected information.

13. The washing machine for removing the foam based on the drainage information of claim 9, wherein the controller configured to execute the foam removal logic is further configured to repeatedly perform water supply and drainage of the functional module,wherein the controller is further configured to:calculate second drainage information related to drainage during a drainage operation of the functional module after performing the foam removal logic; anddetermine whether to repeat the foam removal logic, based on the second drainage information.

14. The washing machine for removing the foam based on the drainage information of claim 9, wherein the foam removal logic includes a first foam removal logic and a second foam removal logic,wherein the first foam removal logic is configured to remove a larger amount of foam than an amount of foam removed by the second foam removal logic,wherein the controller configured to execute the foam removal logic is further configured to select the first foam removal logic in response to that the set course is a course set to be completed faster than a standard course is or when the first drainage information is greater than a reference value.

15. The washing machine for removing the foam based on the drainage information of claim 14, wherein the first foam removal logic is configured such that the washing machine inputs hot water or a fabric softener into a washing space and subsequently performs water supply and drainage at least one time, thereby removing the foam,wherein the second foam removal logic is configured such that the washing machine performs water supply and drainage at least one time, thereby removing the foam.

16. The washing machine for removing the foam based on the drainage information of claim 9, wherein the controller is further configured to:calculate third drainage information related to drainage during a drainage operation of the functional module;determine whether to terminate the foam removal logic, based on the third drainage information; andupon determination to terminate the foam removal logic, execute a dehydration process.

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