EP4056098A1

EP4056098A1 - Dishwashing machine and method of operating a dishwashing machine

Info

Publication number: EP4056098A1
Application number: EP21161839.2A
Authority: EP
Inventors: Mutlu USLU
Original assignee: Vestel Elektronik Sanayi ve Ticaret AS
Current assignee: Vestel Elektronik Sanayi ve Ticaret AS
Priority date: 2021-03-10
Filing date: 2021-03-10
Publication date: 2022-09-14

Abstract

There is provided a dishwashing machine (100). The dishwashing machine (100_ comprises a controller (134). The dishwashing machine (100) also comprises a motor (160) for driving a spray arm (124) in a washing chamber (104) of the dishwashing machine (100). The controller (134) is arranged to determine an occupancy of the washing chamber (104) based at least in part on electrical current information of the motor (160), and the controller (134) is arranged to select a washing program based at least in part on the determined occupancy.

Description

Technical Field

The present disclosure relates to a dishwashing machine and a method of operating a dishwashing machine.

Background

Dishwashing machines (also referred to as dishwashers) are used for washing items such as crockery and cutlery. A known dishwashing machine comprises a washing chamber for holding one or more items to be washed, and a washing mechanism for washing those items. Typically, a user can select from a plurality of pre-defined washing cycles via a user interface on a front face of the dishwashing machine.

Summary

According to a first aspect disclosed herein, there is provided a dishwashing machine comprising: a controller; a motor for driving a spray arm in a washing chamber of the dishwashing machine; and wherein the controller is arranged to determine an occupancy of the washing chamber based at least in part on electrical current information of the motor; and wherein the controller is arranged to select a washing program based at least in part on the determined occupancy.
According to some examples, the controller is arranged to use the electrical current information to monitor a current profile of the electric motor as the spray arm rotates.
According to some examples, the controller is arranged to determine the occupancy based at least in part on information of one or more portions of the profile that exceed a threshold current value.
According to some examples, the controller is arranged to determine the occupancy based at least in part on one or more of: a number of portions in the current profile that exceed the threshold current value, where the higher the number the higher the occupancy; an area under a curve of the profile that is above the threshold, the higher the area the higher the occupancy.
According to some examples, the controller is arranged to determine a distribution of the items to be washed within the washing chamber based at least in part on the current information.
According to some examples, the controller is arranged to determine the occupancy of the washing chamber based at least in part on information relating to a degree of moisture in the washing chamber.
According to some examples, the information relating to a degree of moisture is obtained from one or more of: a moisture sensor which is constructed and arranged to sense moisture in the washing chamber; a temperature sensor which is constructed and arranged to sense temperature in the washing chamber, and the controller is arranged to determine the degree of moisture based on the sensed temperature.
According to some examples, the controller is arranged to determine the occupancy during an occupancy determination phase.
According to some examples, the occupancy determination phase is configured to occur prior to a main washing cycle.
According to some examples, during the occupancy determination phase the spray arm is rotated at a constant speed.
According to some examples, a duration of the occupancy determination phase is fifteen minutes or less.
According to some examples, the controller is arranged to use a look-up table to select the washing program.
According to some examples, the motor comprises a brushless direct current motor.
According to a second aspect disclosed there is provided a method of operating a dishwashing machine comprising: determining, by a controller of the dishwashing machine, an occupancy of a washing chamber of the dishwashing machine based at least in part on electrical current information of a motor of a spray arm of the dishwashing machine; and selecting, by the controller, a washing program based at least in part on the determined occupancy.
According to a third aspect disclosed there is provided a computer program comprising computer program code arranged to cause a controller of a dishwashing machine to: determine an occupancy of a washing chamber of the dishwashing machine based at least in part on electrical current information of a motor of a spray arm of the dishwashing machine; and select a washing program based at least in part on the determined occupancy.

Brief Description of the Drawings

To assist understanding of the present disclosure and to show how embodiments may be put into effect, reference is made by way of example to the accompanying drawings in which:

Figure 1 schematically shows a dishwashing machine according to an example;
Figures 2A and 2B schematically show electrical current profiles of a spray-arm motor according to examples;
Figure 3 schematically shows a look-up table according to an example;
Figure 4 schematically shows a method according to an example.

Detailed Description

The present disclosure has applicability to dishwashing machines or dishwashers. Dishwashing machines are used to automate the washing of items including crockery such as plates, bowls, cups, mugs etc. Items to be cleaned may also include cutlery such as knives, forks, spoons, or indeed any other cooking or eating utensil. Other items that may be washed include glassware, food containers etc.
Figure 1 schematically shows an example of a dishwashing machine 100. The dishwashing machine 100 comprises a main body 102, within which there is a washing chamber 104. Washing chamber 104 may also be referred to as a washing cabinet or washing compartment. In the example of Figure 1 the washing chamber 104 comprises a lower portion 106 and an upper portion 108. The lower portion 106 comprises a tray or rack 110 for holding items to be washed. The upper portion 108 comprises a tray or rack 112 for holding items to be washed. The racks 110 and 112 can be moved in and out of the washing chamber 104 on roller assemblies.
Items to be washed are schematically shown at 114. In the example of Figure 1 the items to be washed are schematically represented by plates 116 and 118 on rack 112, and plates 120 and 122 on rack 120. Of course, there may alternatively be any other type of item to be washed or combination of items to be washed.
In the example of Figure 1 a washing mechanism 123 comprises spray arm 124 in lower portion 106, and spray arm 126 in upper portion 108. In other examples the upper spray arm 126 is omitted. Each spray arm comprises a series of outlets (such as holes or nozzles) which can spray water upwardly and/or downwardly towards the items to be washed 114, while the spray arms 124 and 126 rotate. The items to be washed 114 are thus cleaned by a combination of the impact of high temperature water sprayed from the spray arms, and high temperature water vapour which forms in the washing chamber 104.
In the example of Figure 1 the spray arm 124 is connected to shaft 125. The shaft 125 enables rotation of spray arm 124 about a central axis of the shaft 125. The shaft 125 and spray arm 124 may be considered to be comprised in a spray arm assembly 121. In the example of Figure 1 the spray arm 126 is connected to shaft 127. The shaft 127 enables rotation of spray arm 126 about a central axis of the shaft 127. The shaft 127 and spray arm 126 may be considered to be comprised in a spray arm assembly 129.
The dishwashing machine 100 further comprises water inlet schematically shown at 128 and water outlet schematically shown at 130, for enabling water to be fed into and taken out of the dishwashing machine respectively. In some examples a heater element (not shown) is provided for heating water as necessary. In other examples hot and cold water is drawn from a building's supply as required. A power connection is schematically shown at 132, which enables the dishwashing machine to be connected to mains electrical power for powering the dishwashing machine.
A water pump is schematically shown at 150. The water pump 150 is constructed and arranged to distribute water around the dishwashing machine 100. For example, the water pump 150 can pump water to spray arms 124 and 126. Water that has been sprayed falls back down to a base or sump 152 of the dishwashing machine 100, from where that water can be recycled (after filtering, in some examples) by the pump 150.
According to some examples a motor 160 is provided for causing rotation of spray arm 124. According to some examples, motor 160 comprises a brushless direct current (BLDC) motor. In some examples, a motor may also be provided for causing rotation of spray arm 126.
According to some examples, a moisture sensor 162 is provided. The moisture sensor 162 is constructed and arranged to detect a level of moisture within the washing chamber 104.
According to some examples, a temperature sensor 164 is provided. The temperature sensor 164 is constructed and arranged to detect a temperature within the washing chamber 104.
A controller is schematically shown at 134 for controlling operations of the dishwashing machine. The controller 134 may comprise at least one memory and at least one processor. The controller 134 can, for example, cause the dishwashing machine to operate according to one or more washing cycles. The available washing cycles may differ from each other by temperature and/or duration, for example. A display 138 is also provided which can display information to a user. This may include information such as displaying a washing cycle selection, as well as information such as time remaining of a washing cycle that is in progress. A user interface is schematically shown 136. A user may control certain operations of the dishwashing machine via user interface 136, such as initiating a washing cycle. The controller 134 may also control other operations of the dishwashing machine 100. For example, the controller 134 may be configured to control operations of the motor 160. The controller 134 may also receive information from one or more components within the dishwashing machine. For example, the controller 134 may receive information from one or more of: motor 160; moisture sensor 162; temperature sensor 164.
A door of the dishwashing machine 100 is schematically shown at 140. In Figure 1 the door 140 is shown in an open position enabling access to washing chamber 104.
A washing cycle generally comprises three main stages: (i) wetting; (ii) injection of detergent, (iii) rinsing. In some examples one or more of these steps may be omitted. For example, a rinse wash may include just a rinsing cycle. Whichever steps are included or not included, the washing of the washing load may be generally termed a washing cycle. In some examples the rinsing stage is followed by a drying stage.
In known dishwashing machines, one or more user-selectable programs are typically provided. The dishwashing machine is therefore reliant upon a user making a correct judgement of a washing program to select. This may result in wastage of water and energy if a user selects a program whose intensity is higher than required. Alternatively, there may be improper cleaning if a user selects a program whose intensity is lower than required. Some advanced models of dishwashing machine have attempted to provide automatic program selection based on a sensed occupancy and/or dirtiness of the load, but such advanced machines typically employ expensive and/or additional sensing equipment in order to do so.
As will be explained in more detail below, according to some examples the controller 134 is arranged to determine an occupancy of the washing chamber 104, and to select a suitable washing program based at least in part on the determined occupancy. By "occupancy" is meant how full the dishwashing machine 100 is. That is where there is a high occupancy there will be many items in the dishwashing machine to be washed, and where there is a low occupancy there will not be many items in the dishwashing machine to be washed. According to examples a washing cycle that is automatically selected by the controller 134 will have an intensity (e.g. temperature and/or duration) based upon the determined occupancy. For example the higher the occupancy, the higher the intensity of the selected washing program. For example, the higher the occupancy, the higher the temperature and/or duration may be of the selected washing cycle. The lower the occupancy, the lower the temperature and/or duration may be of the selected washing cycle.
According to some examples, the controller 134 is arranged to determine an occupancy of the washing chamber 104 based at least in part on obtained electrical current information of the motor 160. As the motor 160 rotates, its electrical current will vary dependent upon whether water that is sprayed from spray arm 124 is striking an item to be washed, such as a dish. This is because of the additional reaction force that is created by the sprayed water striking an item to be washed, compared to being sprayed into an empty space. The current may also vary due to water falling on to the spray arm 124 from one or more items to be washed, which may have an effect of a force acting on the spray arm. In some examples, the electrical current information that is obtained is phase current information. According to some examples, the electrical current information is obtained from an inverter of the motor 160. According to some examples, it may be considered that the electrical current information is representative of inertia of the spray arm 124. That is, in some examples it may be considered that the inertia of the spray arm increases when the sprayed water sprays on to an item to be washed, compared to when the sprayed water sprays in to an empty space. According to some examples, the current may vary in dependence on distance between an item to be washed and the spray arm. In some examples, the closer an item to be washed is to the spray arm, the higher the current will be.
Figures 2A and 2B show example electrical current profiles of motor 160. In each of Figures 2A and 2B, electrical current of motor 160 is represented on the Y-axis. Position of the spray arm 124 is represented on the X-axis. For example, the X-axis may represent a rotational position of the spray arm 124 in degrees. As the spray-arm 124 rotates, it can be seen that the current varies, and that there are a number of peaks and troughs in the current profile. These peaks and troughs may also be referred to as "ripples". According to some examples, and as shown in Figures 2A and 2B by the dashed line, a nominal current limit or threshold current value is set. In some examples, when the current goes above the threshold value it is determined that there are one or more items to be washed in that region of the dishwashing machine. Therefore according to some examples the more peaks there are in the current profile, or the larger the area under the curve which is above the threshold current value, the higher the occupancy is considered to be. In the example of Figures 2A and 2B there are more peaks in Figure 2B than in Figure 2A, and therefore Figure 2B represents a washing chamber having a higher level of occupancy than in Figure 2A. According to some examples, the peaks or ripples may be expressed as a percentage. For example, it may be determined for what percentage of the spray arm's rotation a current ripple is present. The higher the percentage, the higher the occupancy.
For example, it may be considered that Figure 2A represents a washing chamber having a 75% occupancy. In some examples, it would take approximately 6 minutes for the washing chamber to reach a moisture level of 80 to 100% at a 75% occupancy level.
For example, it may be considered that Figure 2B represents a washing chamber having a 99% occupancy. In some examples, it would take approximately 3 minutes for the washing chamber to reach a moisture level of 80 to 100% at a 99% occupancy level.
It will also be understood that in some examples, the controller 134 can determine not only an overall occupancy level in the dishwashing machine 100, but also where in the dishwashing machine the occupancy occurs. That is, according to some examples the controller 134 can determine a distribution of items to be washed within the washing chamber. For example, the controller 134 may be able to determine in which quadrant the items to be washed are loaded or most heavily loaded. According to some examples, the controller 134 achieves this by comparing the current peaks with position of the spray arm 124 (e.g. angular rotation). Where there are separate motors for upper and lower spray arms, the controller 134 can also determine distribution between upper and lower portions of the dishwashing machine. The controller 134 may then select a washing cycle program accordingly. For example, and dependent on distribution, the controller could cause the lower portion 106 of the washing chamber 104 to be washed at a different intensity to the upper portion 108.
According to some examples, the controller 134 checks whether the ripples occur in the same position for a certain number of spray arm rotations. Once the controller is satisfied that the ripples are occurring in the same place on each spray arm rotation, then it can be considered with a reasonably high degree of certainty that the determined occupancy and/or distribution is correct.
According to some examples the controller 134 is arranged to determine the occupancy of the washing chamber 104 based at least in part on obtained information relating to a level or degree of moisture in the washing chamber. According to some examples, the degree of moisture may be represented as a percentage. According to some examples, the degree of moisture may be expressed as a relative humidity percentage. According to some examples, information of the degree of moisture is obtained from moisture sensor 162. According to some examples, temperature information is obtained from temperature sensor 164, and the degree of moisture may be extrapolated from the temperature. According to some examples, a timer is used to determine how long it takes for the washing chamber 104 to reach a threshold moisture. For example, the threshold moisture may be a relative humidity percentage. According to some examples, the threshold moisture lies in a range of 75% to 99% relative humidity. According to some examples, the threshold moisture is 99% or about 99%. According to some examples, the higher the occupancy, the more quickly the threshold moisture will be reached.
According to some examples it will be appreciated that the occupancy of the washing chamber 104 is determined based on at least two factors: electrical current information of the motor 160 and information of a degree of moisture. Using these two factors provides a high reliability that the determined occupancy is correct. According to some examples the electrical current information of the motor 160 and information of a degree of moisture in the washing chamber are determined in parallel. To this extent, it may be considered that the controller is arranged to carry out parallel data analysis.
According to some examples, there is an occupation determination phase. In some examples, the occupation determination phase may comprise either or both of the determining occupancy based on motor current information and determining occupancy based on moisture information. In some examples, the occupancy determination phase begins before the main washing cycle. For example, the occupancy determination stage may occur before the usual initial wetting stage, in some examples. In some examples, the wetting stage doubles as the occupancy determination phase.
According to some examples, during the occupancy determination phase the spray arm 124 is caused to rotate at a relatively low speed. According to some examples, during the occupancy determination phase the spray arm 124 is caused to rotate at a speed that is lower than the maximum speed of the spray arm 124. According to some examples, during the occupation determination phase the spray arm 124 is rotated at a constant speed. According to some examples, during the occupancy determination phase the spray arm 124 is caused to rotate at a speed in a range of 200 to 300 revolutions per minute.
According to some examples, a duration of the occupancy determination phase is in a range of ten to fifteen minutes. According to some examples, a duration of the occupancy determination phase is no more than fifteen minutes. According to some examples, a duration of the occupancy determination phase is fifteen minutes or about fifteen minutes. According to some examples, it takes the washing chamber 104 about ten to fifteen minutes to reach a moisture level of 99% (e.g. relative humidity of 99%).
Once the occupancy determination phase is complete, in some examples the controller then uses the obtained information of current information of the motor 160 (e.g. information of ripples or spikes) and information relating to a degree of moisture in the washing chamber, and compares that information with a look-up-table (LUT), in order to select a suitable washing cycle. An example LUT 300 is shown in Figure 3. The LUT 300 comprises: a first column 302 representing time taken to meet moisture threshold (in minutes); a second column 304 which represents a percentage of current ripples; a third column 306 that represents percentage occupancy level; and a fourth column 308 that represents a washing program that is to be selected based upon the parameters of the first three columns. For example, and looking at the first row, a short washing program for low dirtiness is selected if it takes 15 minutes to reach the threshold moisture, there is 0 to 10% current ripples, and there is an occupancy level of 0 to 8%. On the other hand, and looking at the last row of the LUT, a long washing program for high dirtiness is selected if it takes 1 to 2 minutes to reach the threshold moisture, there is 92 to 100% current ripples, and there is an occupancy level of 100%. According to some examples, the dishwashing machine 100 is loaded with information of the LUT at the time of manufacture or assembly of the dishwashing machine 100. According to some examples the moisture threshold (column 302) comprises a moisture of 99%.
An example method will now be described with respect to Figure 4.
As shown at S1 a user, deciding that they want to wash the load that is present in the dishwashing machine 100, initiates a washing cycle in the dishwashing machine 100. In some examples this is done by pressing a button or the like on the user interface 136. According to some examples the user simply needs to initiate the washing cycle - the user does not need to select a suitable washing cycle.
At S2, the dishwashing machine begins an occupancy determination phase, to determine how full the dishwashing machine is. As schematically shown, step S2 may comprise a sub-step S3 of determining occupancy based at least in part on electrical current information of the motor 160, and S4 of determining occupancy based at least in part on information relating to a degree of moisture in the washing chamber. In some examples, step S2 may comprise only step S3. In some examples, step S2 may comprise only step S4. In some examples, step S2 may comprise both steps S3 and S4. Where S2 comprises both S3 and S4, in some examples S3 and S4 occur in parallel. In some examples, the durations of S3 and S4 are the same. In some examples, the durations of S3 and S4 are different. In some examples, S3 and S4 may occur partially in parallel, where one of S3 and S4 starts and/or finishes before the other. In some examples, S3 and S4 occur in series. Where S3 and S4 occur in series, S3 may occur before S4, or S4 may occur before S3. In some examples, S2 takes no longer than 15 minutes.
At S5, and in response to the determination at S2, the controller selects a washing program based at least in part on the determined occupancy.
Then, at S6 the controller 134 causes the selected washing cycle to be initiated.
It will be appreciated that the described dishwashing machine and method enable determination of occupancy of the washing chamber, and therefore selection of an appropriate washing cycle, in a manner that does not require complicated and expensive equipment over a standard dishwashing machine. In some examples, no additional hardware is required above what is provided in a standard BLDC drive dishwasher. Where moisture and/or temperature sensors are required, these can be installed in a relatively cheap and simple to install manner. The determination of occupancy can be carried out by a standard controller of a dishwashing machine, once programmed accordingly. In some examples, aside from placing detergent in the machine and pressing a start button (or the like), no input is required from the user to select a suitable washing cycle.
According to some examples, the controller 134 is arranged to utilise a self-learning mechanism. For example, the controller 134 can learn overt time whether it has correctly determined occupancy and/or selected the most appropriate washing cycle for the determined occupancy, and adapt the algorithm or algorithms it employs over time. Therefore, in some examples the controller 134 and dishwasher 100 may be considered adaptive.
Although the description has predominantly discussed examples in the context of a motor 160 in a lower spray arm 124, it will be understood that the concepts discussed herein are applicable to a dishwashing machine having any number of spray arms and any number of corresponding motors. For example, the concepts may relate to any one or more of upper and/or lower spray arm motors.
Although at least some aspects of the embodiments described herein with reference to the drawings comprise computer processes performed in processing systems or processors, the invention also extends to computer programs, particularly computer programs on or in a carrier, adapted for putting the invention into practice. The program may be in the form of non-transitory source code, object code, a code intermediate source and object code such as in partially compiled form, or in any other non-transitory form suitable for use in the implementation of processes according to the invention. The carrier may be any entity or device capable of carrying the program. For example, the carrier may comprise a storage medium, such as a solid-state drive (SSD) or other semiconductor-based RAM; a ROM, for example a CD ROM or a semiconductor ROM; a magnetic recording medium, for example a floppy disk or hard disk; optical memory devices in general; etc.
The examples described herein are to be understood as illustrative examples of embodiments of the invention. Further embodiments and examples are envisaged. Any feature described in relation to any one example or embodiment may be used alone or in combination with other features. In addition, any feature described in relation to any one example or embodiment may also be used in combination with one or more features of any other of the examples or embodiments, or any combination of any other of the examples or embodiments. Furthermore, equivalents and modifications not described herein may also be employed within the scope of the invention, which is defined in the claims.

Claims

A dishwashing machine comprising:
a controller;

a motor for driving a spray arm in a washing chamber of the dishwashing machine; and wherein

the controller is arranged to determine an occupancy of the washing chamber based at least in part on electrical current information of the motor; and wherein

the controller is arranged to select a washing program based at least in part on the determined occupancy.
A dishwashing machine according to claim 1, wherein the controller is arranged to use the electrical current information to monitor a current profile of the electric motor as the spray arm rotates.
A dishwashing machine according to claim 2, wherein the controller is arranged to determine the occupancy based at least in part on information of one or more portions of the profile that exceed a threshold current value.
A dishwashing machine according to claim 3, wherein the controller is arranged to determine the occupancy based at least in part on one or more of: a number of portions in the current profile that exceed the threshold current value, where the higher the number the higher the occupancy; an area under a curve of the profile that is above the threshold, the higher the area the higher the occupancy.
A dishwashing machine according to any of claims 1 to 4, wherein the controller is arranged to determine a distribution of the items to be washed within the washing chamber based at least in part on the current information.
A dishwashing machine according to any of claims 1 to 5, wherein the controller is arranged to determine the occupancy of the washing chamber based at least in part on information relating to a degree of moisture in the washing chamber.
A dishwashing machine according to claim 6, wherein the information relating to a degree of moisture is obtained from one or more of: a moisture sensor which is constructed and arranged to sense moisture in the washing chamber; a temperature sensor which is constructed and arranged to sense temperature in the washing chamber, and the controller is arranged to determine the degree of moisture based on the sensed temperature.
A dishwashing machine according to any of claims 1 to 7, wherein the controller is arranged to determine the occupancy during an occupancy determination phase.
A dishwashing machine according to claim 8, wherein the occupancy determination phase is configured to occur prior to a main washing cycle.
A dishwashing machine according to claim 8 or claim 9, wherein during the occupancy determination phase the spray arm is rotated at a constant speed.
A dishwashing machine according to any of claims 1 to 10, wherein a duration of the occupancy determination phase is fifteen minutes or less.
A dishwashing machine according to any of claims 1 to 11, wherein the controller is arranged to use a look-up table to select the washing program.
A dishwashing machine according to any of claims 1 to 12, wherein the motor comprises a brushless direct current motor.
A method of operating a dishwashing machine comprising:
determining, by a controller of the dishwashing machine, an occupancy of a washing chamber of the dishwashing machine based at least in part on electrical current information of a motor of a spray arm of the dishwashing machine; and

selecting, by the controller, a washing program based at least in part on the determined occupancy.
A computer program comprising computer program code arranged to cause a controller of a dishwashing machine to:
determine an occupancy of a washing chamber of the dishwashing machine based at least in part on electrical current information of a motor of a spray arm of the dishwashing machine; and

select a washing program based at least in part on the determined occupancy.