Method and control unit for setting an optimal water level during a washing cycle in a dishwasher

Abstract

Method (500) for setting an optimal water level (306) during a washing cycle in a dishwasher (100), wherein the method (500) comprises the following steps: providing (501) a first speed signal (402) to increase the speed of a circulation pump (106) via an interface to the circulation pump (106); and providing (503) a second speed signal (406) to decrease the speed of the circulation pump (106) using a turbidity sensor signal (404) provided by a turbidity sensor (104) to achieve the optimal water level (306), wherein the second speed signal (406) is provided using a predetermined function (700) and / or using a lookup table (800).

Description

[0001] The approach presented here relates to a method and a control unit for setting an optimal water level during a washing process in a dishwasher, according to the main claims.

[0002] Dishwashers have specially designed filter systems to filter out and collect dirt particles released from the dishes, preventing them from re-entering the dishwasher's circulation pump circuit. This filter system functions optimally only when the water column is directly above the filter screen during circulation. Currently, the system indirectly adjusts the pump speed based on the surface area of ​​the dishes, for example, by detecting stable pump operation. However, this does not control or precisely adjust the water level during the wash cycle. Direct measurement of the water level would only be possible with a suitable level sensor, such as a pressure sensor. However, these are not used for cost reasons.

[0003] DE19951839A1 describes a turbidity sensor for a dishwasher that monitors the cleaning fluid and regulates the speed of the circulation pump using a recorded signal curve.

[0004] Starting from this state of the art, the task of the approach presented here is to create an improved method and an improved control unit for setting an optimal water level during a washing process in a dishwasher.

[0005] This problem is solved by a method and a control device for setting an optimal water level during a washing cycle in a dishwasher, comprising the features of the main claims. Advantageous embodiments and further developments of the invention are described in the dependent claims.

[0006] The approach presented here for setting an optimal water level during a washing process in a dishwasher offers a cost and benefit advantage through the expanded use of a potentially already existing turbidity sensor.

[0007] A method for setting an optimal water level during a washing cycle in a dishwasher is presented, the method comprising the following steps: Providing an initial speed signal via an interface to the circulation pump to increase the speed of a circulation pump; and Providing a second speed signal to reduce the speed of the circulation pump using a turbidity sensor signal provided by a turbidity sensor to achieve the optimal water level.

[0008] A dishwasher can be an appliance for the mechanical cleaning of items, such as dishes. The items to be cleaned can be rinsed with solvents or compressed air, which removes solids, liquids, and microorganisms. A wash cycle describes the process of cleaning the items in the dishwasher. A circulation pump can be a pump in a dishwasher used to circulate a quantity of water. A first speed signal can be used to continuously increase the speed of the circulation pump. A second speed signal can be used to decrease the speed of the circulation pump. A turbidity sensor can be a sensor in the dishwasher that generally serves to determine water quality. A turbidity sensor signal can be used to indicate the degree of turbidity of the water.Furthermore, the turbidity signal can be configured to indicate whether the water level is above or below the turbidity sensor. Advantageously, the turbidity signal can be used to control the speed of the circulation pump. For example, a second speed signal can be provided when the turbidity sensor signal indicates that the water level has reached the turbidity sensor. This second speed signal can then be configured to lower the water level by a predetermined amount.

[0009] This approach also offers the possibility of optimizing the dishwasher's filter system with optimal filter self-cleaning, thus ensuring the best possible cleaning of the dishes. Furthermore, the optimized cleaning performance of the filters reduces the risk of re-soiling of dishes from any trapped food residue. Additionally, the turbidity sensor can also be used as a drain control, thereby shortening the draining time.

[0010] According to one embodiment, in the step of providing a second speed signal, the second speed signal can be provided using a predetermined function and / or a lookup table. The lookup table can be a table stored in the dishwasher's memory. According to one embodiment, the lookup table can define a reduction in speed that depends on the amount of water present in the dishwasher and the speed of the circulation pump. A reduction in speed can lead to achieving an optimal water level and therefore optimized washing performance. According to one embodiment, the function can use the amount of water present in the dishwasher, the speed of the circulation pump, and / or the time of provision of the turbidity sensor signal as variables.

[0011] According to one embodiment, the second speed signal can be configured to reduce the speed of the circulation pump until the optimal water level is reached during the rinsing process directly above the surface of a flat sieve.

[0012] According to one embodiment, the steps of the procedure can be repeated when water is refilled into the dishwasher. This ensures optimal washing performance throughout the entire washing process.

[0013] A method for operating a dishwasher is presented, the method comprising the following steps: Increasing the speed of a circulation pump; and Reducing the speed of the circulation pump using a turbidity sensor signal provided by a turbidity sensor to achieve the optimal water level.

[0014] Although the described approach is based on a household appliance, the procedure described here for setting an optimal water level during a washing process in a dishwasher including control unit can be used accordingly in connection with a commercial or professional device, for example a cleaning or disinfection device, a small sterilizer, a large-capacity disinfector or a container washing system.

[0015] The approach presented here further creates a device designed to perform, control, and implement the steps of a variant of the method presented here in appropriate facilities. This embodiment of the invention in the form of a device also allows the problem underlying the invention to be solved quickly and efficiently.

[0016] The device can be configured to read input signals and, using these input signals, determine and provide output signals. An input signal can, for example, be a sensor signal readable via an input interface of the device. An output signal can be a control signal or a data signal that can be provided at an output interface of the device. The device can be configured to determine the output signals using a processing instruction implemented in hardware or software. For example, the device can include a logic circuit, an integrated circuit, or a software module and may be implemented as, or comprised of, a discrete component.

[0017] A computer program product or computer program with program code that can be stored on a machine-readable medium such as semiconductor memory, hard disk memory, or optical memory is also advantageous. If the program product or program is executed on a computer or device, it can be used to carry out, implement, and / or control the steps of the method according to one of the embodiments described above.

[0018] An embodiment of the invention is shown purely schematically in the drawings and is described in more detail below. It shows Fig. 1 a schematic cross-sectional view of a dishwasher according to an exemplary embodiment; Fig. 2 a schematic cross-sectional view of a lower area of ​​a dishwasher including a filter system according to an exemplary embodiment; Fig. 3 A schematic cross-sectional view of a lower area of ​​a dishwasher including water levels during the washing process according to an exemplary embodiment; Fig. 4 a schematic view of a control unit, a turbidity sensor and a circulation pump of a dishwasher according to an exemplary embodiment; Fig. 5 an embodiment of a method for setting an optimal water level during a washing process in a dishwasher according to an embodiment; Fig. 6 three time diagrams showing a current water level, a current circulation pump speed and a sequence of a washing process in a dishwasher according to one embodiment; Fig. 7 a determining function of a rotational speed to be reduced according to an exemplary embodiment; and Fig. 8 a table for determining the rotational speed to be reduced according to an exemplary embodiment.

[0019] Fig. Figure 1 shows a schematic cross-sectional view of a dishwasher. 100 according to one example. The dishwasher 100 This includes a collection pot 102 with a turbidity sensor 104 , a circulation pump 106 as well as a drain pump 108 According to one embodiment, the dishwasher further comprises three spray arms. 110 , 112 , 114 , two dishwashing baskets 116 , 118 and a waterway 120 .

[0020] Experience has shown that cleaning conditions can change during a dishwasher cycle. 100 Changes can happen quickly. Even a tipped-over cup or an awkwardly positioned goblet can ruin the dishwasher. 100 This would significantly alter the available water volume. This would affect both the filter system and the cleaning system of the dishwasher, particularly the circulation pump. 106The intake of air is a major problem. The turbidity sensor 104 can remedy this problem.

[0021] A turbidity sensor 104 It is generally used to determine the water quality of a wash cycle. This wash cycle is used to clean the items being washed, such as dishes and glasses, over an extended period in a circulating cycle. Monitoring changes in water quality is now standard practice. It helps the dishwasher 100 to react to varying levels of soiling with corresponding changes to the wash program. The turbidity sensor 104 is mostly in the hydraulic waterway 120 the washing liquid or also in the collection pot 102 the dishwasher 100 This arrangement can be used to determine the water level in the dishwasher. 100with a suitable method. To date, the only known methods for optimally adjusting the water level in recirculation mode are those in which the water level is measured directly using, for example, a pressure sensor or level sensor. However, these measurement methods require an additional sensor and therefore also incur additional costs.

[0022] The turbidity sensor 104 , which, according to one embodiment, is in the collection pot 102 the dishwasher 100 It is arranged to help control the speed of the circulation pump. 106 to adjust it so that optimal washing operation is achieved. Optimal washing operation refers to adjusting the water level during recirculation directly above the surface of the filter screen. The basic idea is that the procedure for adjusting an optimal water level during a dishwasher wash cycle should be repeated after each new water intake.100 This is a one-time process. Alternatively, the speed of the circulation pump could be readjusted and / or checked at a later time. 106 or the water level after set times, for example at intervals of 15 minutes or as long as no fresh water enters the dishwasher 100 has arrived.

[0023] As already described, the speed of the circulation pump needs to be changed. 106 depending on the cleaning conditions in the dishwasher 100 , for example, the load size and / or surface area, the water inlet volume, and the water return geometry. To determine the optimal wash cycle, the amount of wash water currently in the dishwasher should be considered. 100 located, as well as the speed of the circulation pump 106 or the time at which the turbidity sensor 104The difference between the last two parameters, the speed of the circulation pump, is sufficient. 106 and the time until the turbidity sensor reports a result 104 The effect will be minimal. However, the inertia of the rinsing solution, influenced by dirt, chemicals, and temperature fluctuations, can play a significant role in the time parameter. Therefore, both parameters are conceivable for use in the process.

[0024] The turbidity sensor 104 in the collection pot 102 Can the speed of the circulation pump be adjusted? 106 To determine optimal filter cleaning, the following applies: On the one hand, by a function f(x,y,z), for example f(water quantity, UP rotation speed or time to reach the turbidity sensor signal), where the function is stored in a memory of the dishwasher. 100 is stored, or simplified as a lookup table, which is also stored in the dishwasher's memory. 100is stored.

[0025] Fig. Figure 2 shows a schematic cross-sectional view of a lower area of ​​a dishwasher. 100 including a filter system 200 according to one exemplary embodiment. In the filter system shown. 200 For example, is it something that goes in the dishwasher? 100 out of Fig. 1 built-in filter system.

[0026] The filter system 200 comprises three parts, a coarse sieve 202 , which serves as a coarse dirt filter, a surface sieve 204 , which serves as a fine dirt filter, and a microfine filter 206 Furthermore, the cross-sectional view shows an intake manifold. 208 to the circulation pump, a flow-calmed area 210 , which serves as a dirt collection zone, as well as a filter area 212 to the circulation pump. Above the filter system 200 The sink interior is located 214 the dishwasher 100In addition to the turbidity sensor 104 The control unit is located 216 the dishwasher 100 .

[0027] Will the circulation pump 106 operated with the rinsing solution in such a way that the water level at the filter system 200 far above the surface sieve 204 On the one hand, coarse dirt particles can be removed from the coarse sieve. 202 They can no longer be filtered, and on the other hand, small dirt particles also pass through the coarse sieve. 202 into the area of ​​the microfine filter 206 This then results in the microfine filter becoming clogged. 206 from both sides it can become clogged with dirt particles. Furthermore, in recirculation mode with a high water level, the dirt particles are never filtered out in the designated filter system. 200It is never collected. Therefore, the dirt is inevitably carried over into subsequent washing cycles. As a result, a high rate of re-soiling of the items being washed can be expected.

[0028] If the water level falls below the surface sieve during the washing process 204 If the dirt particles are not sufficiently able to reach the surface sieve by the incoming water, they cannot pass through it. 204 and coarse sieve 202 are conveyed. Some of the dirt particles remain at the edge of the surface sieve. 204 The pump is running. 106 even in a critical environment. As can be seen in the cross-sectional view, there is a [missing information] after the surface sieve. 204 and the turbidity sensor 104 right at the bottom edge of the microfine filter 206 the intake manifold 208 for the circulation pump 106 Does the circulation pump draw in 106 Air flows in here, so the circulation pump runs. 106in an unstable operating condition. Therefore, it cannot guarantee a cleaning effect.

[0029] The method for setting an optimal water level during a washing cycle in a dishwasher 100 The filter system should function optimally. 200 and thus also the optimal self-cleaning of the filter system 200 This is ensured when the self-cleaning of the filter system 200 If the system is optimally adjusted, the cleaning of the dishes will also be correspondingly effective. Additionally, the turbidity sensor can... 104 It can also be used as a pump-out control. When the rinse water is pumped out after a rinse cycle, the circulation pump... 106 The turbidity sensor indicates that the process is switched off. 104 The water level at the sensor itself indicates that very little water remains in the collection tank. This allows the run-on time of a pumping cycle to be shortened.

[0030] Fig. Figure 3 shows a schematic cross-sectional view of a lower area of ​​a dishwasher. 100 including water levels 302 , 304 , 306 , 308 , 310 during the washing process according to an exemplary embodiment. The lower dishwasher section shown is, for example, a section in Fig. 1 shown lower area of ​​the dishwasher 100 .

[0031] The water level 302 The groundwater inlet extends into the interior of the sink. 214 the dishwasher 100 After an initial water intake, the circulation pump 106 The speed was set to a starting speed and increased continuously, with the water level decreasing proportionally to the increase in speed, until the water level 304 for speed control using the turbidity sensor 104This is reached. The turbidity sensor detects this. 104 that, at a certain speed of the circulation pump 106 , a turbidity sensor level has been reached. The turbidity sensor then adjusts. 104 the speed of the circulation pump 106 based on a specific rotational speed, resulting in an optimal water level 306 during the washing process. The optimal washing process is achieved by adjusting the water level. 306 directly above the surface sieve 204 the dishwasher 100 is adjusted. It can also be seen here that the water level is changing. 304 for adjusting the circulation pump speed at the turbidity sensor 104 between the water level 302 after the groundwater inflow and a possible unstable pump operation 308 at the intake manifold 208 the circulation pump 106 is located. Also the water level 310The device for switching off the drain pump should be positioned below the turbidity sensor level. This also allows for drain pump control.

[0032] Fig. Figure 4 shows a schematic representation of a control unit. 216 , a turbidity sensor 104 as well as a circulation pump 106 a dishwasher according to one exemplary embodiment. Regarding the control unit 216 , the turbidity sensor 104 and the circulation pump 106 Could these be components from the dishwasher? Fig. 1 and Fig. 2 trade.

[0033] The control unit 216 is trained to issue an initial turn signal 402 via an interface to the circulation pump 106 to provide the first speed signal 402 is designed to control the speed of the circulation pump 106 to increase. The turbidity sensor 104is designed to determine the turbidity level of the water and to generate a turbidity sensor signal representing the turbidity level 404 to the control unit 216 to provide. The turbidity sensor signal 404 It also indicates whether the turbidity sensor is functioning. 104 located below or above the water level. The control unit 216 is in turn designed to use the turbidity sensor signal 404 a second speed signal 406 to the circulation pump 106 to provide the second speed signal 406 is designed to control the speed of the circulation pump 106 to reduce until an optimal water level is reached.

[0034] For the present method of setting an optimal water level during a washing cycle in a dishwasher, the statement about the water quality, which is determined by the turbidity signal, is crucial. 404which usually provides information is irrelevant. Furthermore, the turbidity signal is used 404 No operating times or interval times for the circulation pump are determined or regulated. Only the reaching of the water level is triggered once, based on the conditions set in the dishwasher, using the turbidity sensor signal. 404 The ramp control of the circulation pump speed serves to precisely adjust the water level to the turbidity sensor. 104 to change. The water level reaching the turbidity sensor. 104 (At time t-TS and at rotational speed n-TS) represents a load-dependent condition in the dishwasher. The other conditions result from the amount of groundwater present in the wash drain and the rotational speed at which the turbidity sensor is activated. 104The system reports certain conditions. Based on these conditions, a rotational speed is later determined to adjust the circulation pump speed for the subsequent rinsing process until the next water inlet. This adjusted speed is intended to bring the water level to the position of the surface screen during recirculation.

[0035] Fig. Figure 5 shows an embodiment of a method 500 for setting an optimal water level during a washing cycle in a dishwasher according to an exemplary embodiment. The method 500 can, for example, be done using the methods based on Fig. 1 described dishwasher as well as the one in Fig. The control unit described in section 4 will be used.

[0036] The procedure involves one step 501 , in which an initial speed signal for increasing the speed of a circulation pump is provided via an interface to the circulation pump. Finally, the method comprises a step503 , in which a second speed signal is provided to reduce the speed of the circulation pump using a turbidity sensor signal provided by a turbidity sensor in order to achieve an optimal water level.

[0037] Fig. Figure 6 shows three time diagrams. 600 , 606 , 612 with a current water level, a current circulation pump speed and a washing process in a dishwasher according to one embodiment.

[0038] The upper time chart 600 Figure 602 shows the time parameter on the x-axis as a function of a water level in millimeters on the y-axis. Figure 604 is the average time diagram. 606 The graph shows the time parameter on the x-axis (608) as a function of the circulation pump speed per minute on the y-axis (610). The lower time diagram 612Figure 614 shows the time parameter on the x-axis as a function of a possible sequence of a dishwasher wash cycle on the y-axis. Figure 616 shows the time diagrams. 600 , 606 , 612 are arranged parallel to each other, so that the individual parameters, i.e. water level, circulation pump speed and progress of the rinsing process, have the same time parameter 602 , 608 , 614 to share and therefore the same procedure is shown.

[0039] The upper time graph shows the same water levels as from Fig. 3 on: The water level 302 after the groundwater inlet, the water level 304 for speed control using the turbidity sensor, the optimal water level 306 During rinsing operation, water level 308 in case of a potentially unstable pump operation and the water level 310 to switch off the drain pump.

[0040] The mean time graph 606It is divided into three speed sections, namely the maximum circulation pump speed 618 , the optimal circulation pump speed for optimal rinsing operation 620 and the circulation pump speed for starting the ramp control 622 .

[0041] Based on the timeline below 612 The individual process steps will now be explained, taking into account the current water level and rotational speed. In the water intake phase... 624 The dishwasher's circulation pump speed is at 0. The water level rises steadily to a maximum. After the water intake... 624 The calming phase follows. 626 The circulation pump is set to a starting speed. After the water level has calmed down, for example after one minute, the circulation pump is restarted with a continuous increase in speed during the circulation pump ramp control phase. 628The engine is ramped up. During this phase, the water level decreases proportionally to the increase in rotational speed. During the phase of the rotational speed reduction... 630 Depending on the load conditions inside the dishwasher, the turbidity sensor will detect when the water level reaches the sensor's threshold at a specific rotation speed. Once the water level is reached, the circulation pump will adjust to a specific speed, which will be maintained during the wash cycle. 632 The optimal water level has been reached. The rinsing process can then continue normally. In the final phase, the pumping phase... 634 , the turbidity sensor can also be used to control the drain pump or the lye pump 636 This is where the pumping phase comes in. 634This is also represented as a separate process step. If the water level is detected during pumping, a follow-up time of, for example, 5 to 10 seconds should be sufficient to pump out the remaining water from the collection tank. This would ensure time-optimized pumping control.

[0042] In another embodiment (not shown), after determining the optimal rotational speed, the mechanical cleaning performance could be increased. Depending on the rotational speed, additional water is added to the dishwasher system. Based on the current rotational speed and the amount of water added, the circulation pump speed is increased until the water level is again within the optimal range for washing operation, using a speed table for this purpose. The speed can be readjusted at any time during the washing process, even in the worst-case scenario if the turbidity sensor detects too much air. This condition is indicated by fluctuations in the sensor's signals. In this case, the circulation pump speed must be reduced back to the starting speed, and the ramp control can then be used to regulate the speed as described previously.

[0043] Fig. 7 shows a determining function700 the speed to be reduced according to an exemplary embodiment.

[0044] The x-axis 702 This shows the detected rotational speed at the turbidity transmitter level in revolutions per minute. The number of detected revolutions ranges from 2500 to 4000 revolutions per minute. The y-axis 704 This indicates the number of revolutions per minute (RPM) by which the speed of the circulation pump should be reduced. The number of RPM to be reduced ranges from... 0 until 140 The three straight lines within the function represent the amount of water present in the dishwasher's wash cycle, with the bottom line being... 706 3 liters, the middle straight 708 3.5 liters and the upper straight 710 4 It displays liters. These values ​​are, of course, only examples.

[0045] Reading the function works as follows: The value sought is the reducing number of revolutions per minute. For example, if there are 3.5 liters of water in the dishwasher's wash cycle and the turbidity sensor detects a speed of 3500 revolutions per minute at the sensor level, the speed is adjusted by reducing the detected speed of 3500 revolutions per minute by 80 revolutions per minute.

[0046] Fig. Figure 8 shows a table for determining the rotational speed to be reduced according to an exemplary embodiment.

[0047] In the left column 802 The table shows the amount of water in liters used in the dishwasher during the wash cycle. The water volume ranges from 3 liters to 3.5 liters to 4 liters. (In the table row...) 804The table displays the detected rotational speeds at the turbidity sensor level in revolutions per minute (RPM). These speeds range from 2500 to 4000 RPM inclusive. The value to be determined is shown in each table cell. 806 is the number of revolutions to be reduced.

[0048] Determining the required speed reduction yields the following speed values: With an existing water quantity of 4 liters and a speed of 2500 An error message, represented by the letter F in the table, is issued if too much water is lost during the rinsing process. This can happen, for example, if a cup tips over. With a water level of 4 liters and a rotation speed of 2750 Another error message appears. With a water level of 4 liters and a rotational speed of 3000The number of revolutions to be reduced is determined to be 140 revolutions. With a water volume of 4 liters and a rotational speed of 3250 The number of rotational speeds to be reduced is determined by 120 Revolutions determined. With a water quantity of 4 liters and a rotational speed of 3500 The number of rotational speeds to be reduced is determined by 100 The number of revolutions is determined. With a water volume of 4 liters and a rotational speed of 3750, the number of revolutions to be reduced is calculated using... 80 The number of revolutions is determined. With a water volume of 4 liters and a rotational speed of 4000, the number of revolutions to be reduced is calculated using... 60 Revolutions determined. With a constant water volume of 4 liters and an increase in the detected revolutions in increments of 250, it should be noted that the number of revolutions to be reduced per minute is proportionally, for example, by each increase. 20The number of revolutions decreases as the detected rotational speed increases.

[0049] With a water quantity of 3.5 liters and a rotational speed of 2500 An error message appears. With a water volume of 3.5 liters and a rotational speed of 2750 The number of revolutions to be reduced is determined to be 140 revolutions. With a water volume of 3.5 liters and a rotational speed of 3000 The number of rotational speeds to be reduced is determined by 120 Revolutions determined. With a water quantity of 3.5 liters and a rotational speed of 3250 The number of revolutions to be reduced is determined by 100 revolutions. With a water volume of 3.5 liters and a rotational speed of 3500 The number of rotational speeds to be reduced is determined by 80 Revolutions determined. With a water quantity of 3.5 liters and a rotational speed of 3750The number of revolutions to be reduced is determined to be 60 revolutions. With a water volume of 3.5 liters and a rotational speed of 4000 The number of rotational speeds to be reduced is determined by 40 The number of revolutions was determined, although there is a slight reduction in speed, presumably because too much water was added at the beginning of the rinsing process. Values ​​with this slight reduction in speed are marked with an asterisk in the table. With a constant water quantity of 3.5 liters and an increase in the detected speeds in 250er It should be noted that the number of rotational speeds to be reduced per minute is proportional to each step. 20 The number of revolutions decreases as the detected rotational speed increases.

[0050] With a water quantity of 3 liters and a rotational speed of 2500 The number of rotational speeds to be reduced is determined by 140Revolutions determined. With a water quantity of 3 liters and a rotational speed of 2750 The number of rotational speeds to be reduced is determined by 120 Revolutions determined. With a water quantity of 3 liters and a rotational speed of 3000 The number of rotational speeds to be reduced is determined by 100 Revolutions determined. With a water quantity of 3 liters and a rotational speed of 3250 The number of rotational speeds to be reduced is determined by 80 Revolutions determined. With a water quantity of 3 liters and a rotational speed of 3500 The number of rotational speeds to be reduced will be mit 60 Revolutions determined. With a water quantity of 3 liters and a rotational speed of 3750 The number of rotational speeds to be reduced is determined by 40The revolutions are determined, resulting in a slight reduction in speed. With a water quantity of 3 liters and a speed of 4000 The number of rotational speeds to be reduced is determined by 20 The number of revolutions is determined, although a slight reduction in speed also occurs. With a constant water volume of 3.5 liters and an increase in the detected revolutions in increments of 250, it should be noted that the number of revolutions to be reduced per minute is proportional to each increase. 20 The number of revolutions decreases as the detected rotational speed increases, and the number of revolutions to be reduced also decreases as the amount of water in circulation decreases. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 19951839 A1

[0003]

Claims

[1] Method (500) for adjusting an optimal water level (306) during a washing process in a dishwasher (100), wherein the method (500) comprises the following steps: Providing (501) a first speed signal (402) to increase the speed of a circulating pump (106) via an interface to the circulating pump (106); and Providing (503) a second speed signal (406) to reduce the speed of the circulation pump (106) using a turbidity sensor signal (404) provided by a turbidity sensor (104) to achieve the optimal water level (306). [2] Method (500) according to one of the preceding claims in which, in the step of providing (503) a second speed signal (406), the second speed signal (406) is provided using a predetermined function (700) and / or using a lookup table (800). [3] Method (500) according to claim 2, wherein the function (700) uses as variables a quantity of water present in the dishwasher (100) and / or the rotational speed of the circulation pump (106) and / or a time of provision of the turbidity sensor signal (404). [4] Method (500) according to claim 2, wherein the lookup table (800) defines a reduction in rotational speed which depends on the amount of water present in the dishwasher (100) and the rotational speed of the circulation pump (106). [5] Method (500) according to one of the preceding claims, wherein in the step of providing (503) a second speed signal (406) the second speed signal (406) is formed to reduce the speed of the circulation pump (106) until the optimal water level (306) is reached during the rinsing process directly above the surface of a surface sieve (204). [6] Method (500) according to one of the preceding claims, wherein the steps of method (501; 503) are repeated upon a further inflow of water into the dishwasher (100). [7] Method for operating a dishwasher (100) wherein the method comprises the following steps: Increasing the speed of a circulation pump (106); and Reducing the speed of the circulation pump (106) using a turbidity sensor signal (404) provided by a turbidity sensor (104) to achieve the optimal water level (306). [8] Control unit (216) configured to control and / or execute the steps of the method (500) according to any of the preceding claims. [9] Dishwasher (100) for washing dishes, wherein the dishwasher (100) comprises a circulation pump (106), a turbidity sensor (104) and a control unit (216) according to claim 8. [10] Computer program product with program code for carrying out the method (500) according to any of the preceding claims, when the computer program product is executed on the control unit (216).

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