EP4157054B1 - System with a dishwasher, method, and computer program product - Google Patents

Description

The present invention relates to a system with a dishwasher, a method and a computer program product.

With dishwashers, it can be a problem that the dishwasher, especially components that carry washing liquid, such as a circulation pump, a spray arm, a dish basket or the inside of a washing container, become dirty over time. For example, a layer of dirt can form on or in these components, which can impair the cleaning performance of the dishwasher. Machine care programs are known as a countermeasure for this. In known dishwashers, these are started in particular after a predetermined number of washing program runs have been carried out. However, this happens regardless of the actual degree of soiling of the dishwasher. It therefore happens that the machine care program is started too early or too late. In one case, energy, cleaning agents and water are then used unnecessarily, in the other case, the cleaning performance of the dishwasher can already be noticeably impaired when the machine care program is started. This can also lead to premature aging of components or the failure of functional units that are affected by the dirt.

EN 10 2008 040 647 A1 describes a dishwasher in which, when a start signal is given, a special cleaning program is carried out to clean the washing container, in particular by applying washing liquid. EN 10 2008 040 650 A1 describes a dishwasher in which a special rinse cycle is carried out at an increased temperature after a predetermined number of rinse cycles and/or depending on the process parameters of previous rinse cycles.

From the DD 217 557 A1 A method for controlling the addition of cleaning or rinsing agents in washing machines is known, in which the change in the increase of the measuring signal during the addition of cleaning or rinsing agents is detected by one or more sensors, at least one of which responds to surfactant concentration, in particular the Measured values from the sensors are evaluated over time by continuously electronically forming the first derivative of the surface tension function of the washing liquor, and from this, signals for controlling the dosing device are obtained by comparing the change with the setpoint values stored in the program control.

EN 10 2008 024543 A1 describes a dishwasher according to the preamble of claims 1 and 11.

Against this background, one object of the present invention is to improve the operation of a dishwasher.

According to a first aspect, a system is proposed with a dishwasher, preferably a domestic dishwasher, with a control device for carrying out a washing program for washing dishes arranged in a washing compartment of the dishwasher, with a sensor unit for detecting a temporal profile of at least one sensor signal of a washing solution that is used to wash the dishes, and for outputting the detected temporal profile of the at least one sensor signal, with a storage unit for storing the temporal profile of the at least one sensor signal, and with a determination unit for determining a temporal function value based on the temporal profile of the at least one sensor signal. The control device is set up to carry out a predetermined action depending on the determined temporal function value.

This system has the advantage that the operation of the dishwasher is improved, as not only individual measured values from sensors are taken into account to control the dishwasher, but the temporal development of the sensor signal is also considered. For example, a pre-wash can be stopped as part of a wash program if the turbidity of the wash water only changes slowly, even though the turbidity is high overall. Furthermore, the continuous recording and storage of the sensor signal makes it possible to identify long-term trends, such as a slow increase in the soiling of the dishwasher over several wash program runs, and to take appropriate measures, in particular, a machine care or cleaning program can be carried out in a targeted manner, for example.

The control device or the determination unit can each be implemented using hardware and/or software. In a hardware implementation, the control device or the determination unit can be designed as a computer or as a microprocessor, for example. In a software implementation, the control device or the determination unit can be designed as a computer program product, as a function, as a routine, as part of a program code or as an executable object. The determination unit can be part of the control device, but can also be arranged externally to the dishwasher.

The sensor unit comprises a plurality of sensors, each of which detects a sensor signal from the washing solution. The sensor signal relates to a physical, chemical and/or biological parameter of the washing solution, such as at least a turbidity, a conductivity, a temperature, a sieve contamination and possibly a water hardness and the like. The sensor signal is indicative of a value of the respective parameter. In the following, the term sensor signal refers to the value of the respective parameter, so the sensor signal of a temperature sensor is, for example, 50°C. Several sensors can be provided for the same parameter, which are arranged, for example, at different positions in the dishwasher where they come into contact with the washing solution.

The sensor unit preferably records the at least one sensor signal multiple times in a specific time interval, for example with a frequency of more than 0.5/min, preferably more than 1/min, more preferably more than 2/min, even more preferably more than 6/min. The sensor unit preferably records the sensor signal regularly and/or periodically, preferably with a period length of less than 100 s, preferably less than 60 s, more preferably less than 30 s, even more preferably less than 10 s.

In the present case, a temporal progression of the sensor signal is understood to mean in particular that sensor signals recorded sequentially are stored in a time series, in particular with a time stamp. The time stamp can represent an absolute time, but preferably the time stamp refers to a start time of the washing program run or to a switch-on time of the dishwasher. The temporal progression of the sensor signal is available, for example, as a table, with the corresponding time stamp being assigned to a respective value of the sensor signal.

The storage unit is designed, for example, as a data storage device, such as a flash memory. The storage unit can be designed as a separate device, but can also be a component of the sensor unit, the detection unit or the control device.

In the present case, a temporal function value is understood to mean a value derived from the temporal progression. To determine the temporal function value, for example, at least two of the stored values are used, preferably two directly consecutive values, further preferably the entire time profile is used. Examples of the time function value include a derivative of the sensor signal with respect to time or an integration of the sensor signal over time. When determining the time function value, time-dependent and/or sensor signal value-dependent weights can be used, for example the first minute of the time profile can be weighted more or less strongly than the further time profile and/or sensor signal values that are above a certain threshold can be weighted more or less strongly than the sensor signal values that are below the threshold, and the like.

The predetermined action that the control device performs includes, for example, adjusting a washing program parameter, terminating a sub-program step, issuing a message to a user of the dishwasher, setting a status indicator and the like.

For example, the control device compares the determined temporal function value with a predetermined threshold value or a function value of a predetermined function, wherein the argument for determining the function value of the predetermined function depends, for example, on a time interval on which the determined temporal function value is based.

The proposed system therefore differs in particular from systems in which monitoring or control is carried out based only on the current value of the sensor signal.

According to one embodiment of the system according to the invention, the sensor unit comprises a turbidity sensor for detecting a turbidity of the washing liquor, preferably an optical turbidity sensor, and/or a conductivity sensor for detecting a conductivity of the washing liquor, preferably a spectroscopic impedance sensor, and/or a temperature sensor for detecting a temperature of the washing liquor.

In embodiments, the sensor unit further comprises a water hardness sensor for detecting water hardness, a soiling sensor for detecting soiling of the dishes, in particular a chemical composition of the soiling, a load sensor for detecting a load of the dishwasher and/or a detergent sensor for detecting a type of detergent.

For each of these sensors, the sensor unit is set up to detect the temporal progression of the sensor signal and the determination unit is set up to determine the respective temporal function value. The control device is set up to carry out the predetermined action depending on each of the possibly several temporal function values.

According to a further embodiment, the sensor unit comprises the turbidity sensor for detecting the turbidity of the washing liquor, preferably an optical turbidity sensor, a conductivity sensor for detecting the conductivity of the washing liquor, preferably a spectroscopic impedance sensor, and a temperature sensor for detecting the temperature of the washing liquor.

In this embodiment, the sensor unit comprises at least the three sensors mentioned. Accordingly, at least three temporal profiles are stored and the determination unit determines a respective temporal function value for each of the three temporal profiles. The control device is set up to carry out the predetermined action depending on each of the three temporal function values.

This has the advantage that a correlation can be determined between the various sensor signals and/or that a more complex analysis can be carried out by the control device in order to carry out the predetermined action. For example, it can be provided that at least two of the three temporal function values are above a respective threshold value or the sum of the three temporal function values is compared with a threshold value and the like.

According to a further embodiment of the system according to the invention, the sensor unit comprises a sieve contamination sensor which is designed to detect a degree of contamination of a sieve arranged in the dishwasher and to output the detected degree of contamination as a further sensor signal.

The storage unit is configured to store a temporal profile of the further sensor signal and the determination unit is configured to determine a further temporal function value based on the temporal profile of the further sensor signal.

The sieve soiling sensor, for example, includes a function that monitors the pump current when the washing liquid is being pumped out of the dishwasher. If the pump current drops shortly after pumping starts, when not all of the washing liquid has been pumped out, and after a short pause in pumping it is initially high again and then quickly drops again, this is an indication that the sieve is dirty and should be cleaned. If the sieve is clean, the washing liquid flows into the pump pot as quickly as it is pumped out. If the sieve is dirty, however, the washing liquid is pumped out of the pump pot faster than it can flow in, so the load on the pump, and therefore the pump current, drops, but after a short wait, as soon as the washing liquid has flowed in, it is high again.

If the sieve is dirty, a predetermined action can be taken, for example, to carry out a sieve cleaning program and/or to prompt the dishwasher user to clean the sieve manually.

According to a further embodiment of the system, the determination unit is configured to integrate the temporal progression of the at least one sensor signal in order to determine an integral value, wherein the control device is configured to carry out a predetermined action depending on the determined integral value.

In this embodiment, the integral value corresponds to the temporal function value. The integral can refer to the entire temporal progression during a wash program run, but can also be limited to partial sections thereof, such as a heating phase or the like.

In embodiments, it is provided that the determination unit compares the integral value with a threshold value and outputs a comparison result, wherein the control device is configured to carry out the predetermined action depending on the comparison result.

According to an embodiment of the system according to the invention, the sensor unit comprises at least two of a turbidity sensor, a conductivity sensor, a temperature sensor and a sieve contamination sensor, wherein the determination unit is preferably set up to integrate the respective temporal course of the at least two sensor signals and to determine a characteristic number on the basis of the at least two integral values, wherein the control device is set up to carry out a predetermined action depending on the determined characteristic number.

The key figure depends in particular on all of the at least two integral values, for example the key figure is a sum or a product of the at least two integral values. An individual weighting factor can be provided for each of the at least two integral values. Since the integral values in this example correspond to a temporal function value, one can also say that the key figure is a function of the temporal function values.

According to a further embodiment of the system, the determination unit is configured to differentiate the temporal progression of the at least one sensor signal in order to determine the differential value, wherein the control device is configured to carry out the predetermined action depending on the differential value.

In this embodiment, the differential value corresponds to the temporal function value. According to the invention, the determination unit is set up to determine a washing program function value depending on the stored temporal profile of the at least one sensor signal for a washing program run, to store the washing program function value and to determine a profile of the washing program function value on the basis of the washing program function value over a plurality of washing program runs, wherein the control device is set up to carry out the predetermined action depending on the determined profile of the washing program function value.

This is particularly advantageous because it allows long-term changes to be identified and appropriate measures to be taken. In particular, statistics can be determined on the influence of different washing program parameters. For example, it can be determined that the filter becomes increasingly dirty when a certain cleaning agent is used, and a higher washing solution temperature can be set as a countermeasure.

In the present case, the rinsing program function value is understood to mean in particular a value that is determined on the basis of the temporal progression of the sensor signal for carrying out a rinsing program. For example, the rinsing program function value can be the integral of the sensor signal progression from a start time of the rinsing program to an end time of the rinsing program or an average value of the temporal derivative during the execution of the rinsing program.

The course of the washing program function value is determined in particular based on a sequence of the washing program function value over several washing program runs, for example as a function of the several washing program function values. An example of this is the sum of the washing program function values that have been determined over several washing program runs since the course was last reset.

For example, a model for determining when machine maintenance or a machine cleaning program should be carried out can be based on the course of the wash program function value. For example, the value of a turbidity sensor is proportional to an amount of dirt dissolved in the wash water. The integral of the temporal course of the turbidity sensor value therefore corresponds, for example, to the amount of dirt that the dishwasher has cleaned in one wash program run. The course of the wash program function value is determined, for example, as the sum of the amounts of dirt from wash program runs carried out one after the other, which results in a total amount of dirt that has been cleaned by the dishwasher. The higher the total amount of dirt, the more likely it is that components of the dishwasher will become dirty. Therefore, the total amount of dirt can, for example, be compared with a threshold value, and if the threshold value is exceeded, a machine cleaning program is carried out.

Another example is based on a conductivity sensor, the value of which is proportional to the active detergent dissolved in the washing solution. Active detergent is understood to mean, for example, detergent that has not yet been used to dissolve dirt. The smaller the value, the higher the probability that components of the dishwasher will become dirty. The course of the washing program function value is determined, for example, as a sum of the reciprocal value of the integral of the temporal course of the conductivity of a respective washing program run, which is an indicator of when a machine cleaning program should be carried out. If the course of the washing program function value determined in this way exceeds a predetermined threshold value, a machine cleaning program is carried out.

Another example is based on a temperature sensor that records the temperature of the washing solution. If a large amount of dishes is arranged in the washing chamber, then heating up the washing solution takes longer with a constant heating output. The time integral of the course of the washing solution temperature from the beginning of a heating phase to the end of the heating phase, when, for example, a predetermined target temperature is reached, is therefore proportional to a total heat capacity or thermal mass of the dishes heated with the washing solution. Since the dish baskets and the washing chamber walls are also heated, a reference measurement can be carried out with the washing chamber empty, the value of which is subtracted from the determined value, for example. Furthermore, a fluctuation in a mains voltage or the like, which has an influence on the heating output of a washing solution heater, can be taken into account here. In this way, for example, the washing program function value of a washing program run is determined. By adding up the washing program function values of washing program runs carried out one after the other, a course of the washing program function value is obtained.

The greater the thermal mass, the more dishes are arranged in the washing chamber and the greater the expected amount of dirt or dirt load of the dishwasher. The course of the washing program function value therefore develops according to the amount of dishes that have been cleaned with the dishwasher, which is an indication of when, for example, machine maintenance is necessary. If the course of the washing program function value exceeds a predetermined threshold, a machine cleaning program is carried out.

In embodiments, the determination unit is configured to store a plurality of temporal profiles of the at least one sensor signal, which were detected and stored during the execution of different washing program runs in the past.

Based on the majority of stored temporal profiles of the sensor signal, it is possible, for example, to use statistics to determine the effect of various rinsing program parameters on the profile of the sensor signal and thus indirectly on the variables correlated with the sensor signal.

According to the invention, the sensor unit comprises at least two of a turbidity sensor, a conductivity sensor, a temperature sensor and a sieve contamination sensor, wherein the determination unit is set up to determine the respective washing program function value depending on the stored temporal profile of the respective one of the at least two sensor signals for a washing program run, to store the respective one of the at least two washing program function values and to determine a metric based on the respective profile of the at least two washing program function values over a plurality of washing program runs, wherein the control device is set up to carry out the predetermined action depending on the determined metric.

The measurement value can be determined, for example, as a sum or a product, preferably with individual weighting, of the washing program function values. The determined measurement value is compared, for example, with a predetermined threshold value, and if the measurement value exceeds the predetermined threshold value, a machine cleaning program is carried out.

For example, the dishwasher has a turbidity sensor, a conductivity sensor, a temperature sensor and a filter contamination sensor. The measurement value can be determined, for example, according to the following equation (1): $$\mathrm{MZ}=\mathrm{a}\cdot \mathrm{T}+\mathrm{b}\cdot \mathrm{L}+\mathrm{c}\cdot \mathrm{H}+\mathrm{d}\cdot \mathrm{N}+\mathrm{e}\cdot \mathrm{D}$$

In equation (1), MZ is the metric value, T is the wash program function value of the turbidity sensor signal, L is the wash program function value of the conductance sensor signal, H is the wash program function value of the temperature sensor signal, N is the number of wash programs performed since the last machine cleaning program performed, D is the wash program function value of the sieve contamination sensor signal, and a, b, c, d, and e are individual weighting parameters for the different wash program function values. If MZ exceeds a predetermined threshold, a machine care program is performed.

According to a further embodiment, the control device is designed to carry out a machine care program and/or a sieve cleaning program depending on the temporal function value and/or the course of the rinsing program function value.

According to a further embodiment, the control device is configured to adapt the current rinsing program, in particular to shorten a sub-program step of the current rinsing program, depending on the temporal function value.

A sub-program step is, for example, soaking, pre-rinsing, main rinsing, final rinsing and/or drying. This embodiment is advantageous because, for example, based on the temporal progression of the turbidity sensor signal, it can be determined that no more additional dirt is being dissolved in the wash liquor. For example, the temporal function value is determined as a differential value based on the temporal progression, which corresponds to the rate of change of the turbidity sensor signal. This is an indication that the items to be washed are clean. The main rinsing sub-program step can then be ended as a predetermined action, which saves time and energy. Other temporal function values, such as that of the conductivity sensor or the temperature sensor, can also be taken into account. If the conductivity sensor signal is very low, this indicates that there is not enough active cleaning agent in the wash liquor to dissolve dirt. In this case, the predetermined action can be, for example, adding more cleaning agent using an automatic dosing system.

Based on the temporal function value of a single sensor signal or on the basis of several temporal function values of different sensor signals, a large number of different indications can be derived and a predetermined action can be triggered in each case. Overall, this improves the operation of the dishwasher.

According to a further embodiment, the detection unit is arranged in a device external to the dishwasher, wherein the dishwasher and the external device each have a communication unit for bidirectional communication.

In this embodiment, the detection unit preferably has greater computing power available than if the detection unit is integrated in the dishwasher. This also allows more complex calculations to be carried out, which enables more precise results.

The communication unit comprises in particular a modem, in particular a mobile radio modem, and/or a network adapter.

The external device in which the detection unit is arranged can be a user's computer or a server on the Internet or the like. The communication connection can be a direct connection or a mediated connection that is mediated via one or more intermediate devices, such as a router. Different technologies and/or communication protocols can be used for different sections of a connection. The communication connection can also be established in sections wired and/or wirelessly. Examples of this are Bluetooth ^® , WLAN, LAN, Firewire, Zig-Bee, mobile communications (2G, 3G, LTE/4G, 5G) and the like. The communication can in particular be cryptographically protected.

In embodiments, the dishwasher has a detection unit and an additional detection unit is arranged in the external device. For example, simple detections can be carried out locally and/or the local detection unit takes over the detection if communication with the external device is disrupted.

According to a second aspect, a method for operating a dishwasher, preferably a household dishwasher, is proposed. The dishwasher comprises a control device for carrying out a washing program for washing items to be washed arranged in a washing compartment of the dishwasher. In a first step, a temporal profile of at least one sensor signal of a washing solution is recorded. In a second step, the temporal profile of the at least one sensor signal is stored. In a third step, a temporal function value is determined on the basis of the temporal profile of the at least one sensor signal. In a fourth step, a predetermined action is carried out depending on the temporal function value determined.

This method has the same advantages as the system of the first aspect. The embodiments and features described for the proposed system apply accordingly to the proposed method.

Furthermore, a computer program product is proposed which comprises instructions which, when the program is executed by a computer, cause the computer to carry out the method described above.

A computer program product, such as a computer program means, can be provided or delivered, for example, as a storage medium, such as a memory card, USB stick, CD-ROM, DVD, or in the form of a downloadable file from a server in a network. This can be done, for example, in a wireless communications network by transmitting a corresponding file with the computer program product or the computer program means.

Further possible implementations of the invention also include combinations of features or embodiments described above or below with respect to the exemplary embodiments that are not explicitly mentioned. The person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the invention.

• Fig. 1 zeigt eine schematische perspektivische Ansicht einer Ausführungsform eines Systems mit einer Geschirrspülmaschine;
• Fig. 2 zeigt ein schematisches Diagramm eines zeitlichen Verlaufs eines Sensorsignals und eines korrespondierenden zeitlichen Funktionswerts;
• Fig. 3 zeigt ein weiteres schematisches Diagramm von zwei zeitlichen Verläufen zweier Sensorsignale und eines jeweiligen zeitlichen Funktionswerts sowie ein schematisches Diagramm eines Verlaufs einer Kennzahl;
• Fig. 4 zeigt ein weiteres schematisches Diagramm eines zeitlichen Verlaufs eines Sensorsignals über mehrere Spülprogrammdurchläufe mit zugeordnetem Spülprogramm-Funktionswert sowie ein schematisches Diagramm eines Verlaufs eines Spülprogramm-Funktionswerts;
• Fig. 5 zeigt zwei schematische Diagramme eines Verlaufs von Spülprogramm-Funktionswerten für unterschiedliche Haushalte;
• Fig. 6 zeigt ein schematisches Blockdiagramm eines Systems mit einer Geschirrspülmaschine;
• Fig. 7 zeigt ein schematisches Blockschaltbild eines Ausführungsbeispiels eines Verfahrens zum Betreiben einer Geschirrspülmaschine; und
• Fig. 8 zeigt ein schematisches Blockschaltbild eines weiteren Ausführungsbeispiels eines Verfahrens zum Betreiben einer Geschirrspülmaschine.

Further advantageous embodiments and aspects of the invention are the subject of the dependent claims and the embodiments of the invention described below. The invention is explained in more detail below using preferred embodiments with reference to the attached figures.

• Fig.1 shows a schematic perspective view of an embodiment of a system with a dishwasher;
• Fig.2 shows a schematic diagram of a temporal course of a sensor signal and a corresponding temporal function value;
• Fig.3 shows a further schematic diagram of two temporal courses of two sensor signals and a respective temporal function value as well as a schematic diagram of a course of a key figure;
• Fig.4 shows a further schematic diagram of a temporal progression of a sensor signal over several washing program runs with an associated washing program function value as well as a schematic diagram of a progression of a washing program function value;
• Fig.5 shows two schematic diagrams of a trend of washing program function values for different households;
• Fig.6 shows a schematic block diagram of a system with a dishwasher;
• Fig.7 shows a schematic block diagram of an embodiment of a method for operating a dishwasher; and
• Fig.8 shows a schematic block diagram of a further embodiment of a method for operating a dishwasher.

In the figures, identical or functionally equivalent elements have been given the same reference numerals, unless otherwise stated.

The Fig.1 shows a schematic perspective view of a system 20 with a dishwasher 1, which is designed here as a household dishwasher. The household dishwasher 1 comprises a washing container 2, which can be closed by a door 3, in particular watertight. For this purpose, a sealing device can be provided between the door 3 and the washing container 2. The washing container 2 is preferably cuboid-shaped. The washing container 2 can be arranged in a housing of the household dishwasher 1. The washing container 2 and the door 3 can form a washing chamber 4 for washing dishes.

Door 3 is in the Fig.1 shown in its open position. The door 3 can be closed or opened by pivoting about a pivot axis 5 provided at a lower end of the door 3. With the help of the door 3, a loading opening 6 of the washing container 2 can be closed or opened. The washing container 2 has a base 7, a ceiling 8 arranged opposite the base 7, a rear wall 9 arranged opposite the closed door 3 and two side walls 10, 11 arranged opposite one another. The base 7, the ceiling 8, the rear wall 9 and the side walls 10, 11 can be made from a stainless steel sheet, for example. Alternatively, the base 7 can be made from a plastic material, for example.

The household dishwasher 1 further comprises at least one dishware holder 12 to 14. Preferably, several, for example three, dishware holders 12 to 14 can be provided, wherein the dishware holder 12 can be a lower dishware holder or a lower basket, the dishware holder 13 can be an upper dishware holder or an upper basket and the dishware holder 14 can be a cutlery drawer. As the Fig.1 further shows, the washware holders 12 to 14 are arranged one above the other in the washing container 2. Each washware holder 12 to 14 can be moved either into or out of the washing container 2. In particular, each washware holder 12 to 14 can be pushed or moved into the washing container 2 in an insertion direction E and pulled or moved out of the washing container 2 in an extraction direction A opposite to the insertion direction E.

A sensor unit 110 is arranged on the base 7, which has at least one sensor for detecting a sensor signal SS (see Fig. 2, 3 , 4 ) of the rinsing water. The sensor unit 110 preferably comprises a turbidity sensor, a conductivity sensor and a temperature sensor. The sensor unit 110 can also comprise other sensors, such as a water hardness sensor and/or a chemical sensor which is set up to detect a chemical composition of the active cleaning agent dissolved in the rinsing water or of the dirt dissolved in the rinsing water. A control device 100, a storage unit 120 and a determination unit 130 are also arranged on the door 3. The sensor unit detects a temporal profile R1, R2, R3 of the sensor signal SS and transmits it to the storage unit 120, which stores it. The determination unit 130 accesses the stored temporal profile R1, R2, R3, determines a temporal function value RES on the basis of this and transmits this to the control device 100. The control device 100 is set up to carry out a predetermined action depending on the temporal function value RES. This is based on the Fig. 2 - 5 explained in more detail in examples.

Fig. 2 shows a schematic diagram with two temporal profiles R1, R2 of a sensor signal SS and two corresponding temporal function values RES1, RES2. This involves, for example, a temporal profile R1, R2 of the conductivity sensor signal SS of a conductivity sensor and the integral of the respective temporal profile R1, R2 as a temporal function value RES1, RES2. The temporal profiles R1, R2 shown were recorded and saved in different wash program runs, for example, and are superimposed on one another in this diagram for better comparability. The horizontal axis shows a time t, the vertical axis shows the amplitude of the sensor signal SS, with a higher amplitude here corresponding to a higher conductivity.

At time t0, for example, cleaning agent is added to the rinsing solution, whereupon the conductivity of the rinsing solution increases. The time course R1 corresponds, for example, to cleaning agent powder and the time course R2 corresponds, for example, to a cleaning agent tablet. The powder dissolves more quickly, which is why the conductivity increases significantly faster than with the tablet. The time function value RES1 therefore increases significantly earlier in the case of the powder than the time function value RES2 in the case of the tablet. The time function value RES1, RES2 corresponds, for example, to a conductivity caused by the cleaning agent. chemical work performed. For example, the items to be washed are clean as soon as the temporal function value RES1, RES2 reaches a predetermined threshold value LIM. In the case of powder, this is the case at a time t1 that is earlier than time t2 in the case of tablets. Therefore, in the case of powder, the next sub-program step, for example a final rinse, can be started at time t1, which saves time and energy.

Fig.3 shows another schematic diagram of two time courses R1, R2 of two sensor signals SS (left diagram) as well as a schematic diagram of a course of a key figure K (right diagram).

The horizontal axis shows a time t, the vertical axis shows the amplitude of the sensor signal SS (left diagram) and the value of the key figure K (right diagram). The time course R1 shows, for example, a temperature sensor signal and thus the temperature of the washing liquor, with heating starting at time t0. The time course R2 shows, for example, a turbidity sensor signal and thus the turbidity of the washing liquor, with circulation of the washing liquor starting at time t0. The temperature rises to a target value, then heating is stopped, which is why the temperature then drops again. The turbidity increases sharply at the beginning because a lot of dirt is being loosened, but the increase slowly decreases because the dishes get cleaner and cleaner, so that less new dirt can be loosened. The diagram also shows the areas A1, A2 of the respective time course R1, R2 up to a time t1. The area A1, A2 results as the integral over time t of the respective temporal course R1, R2 and corresponds to a temporal function value RES (see Fig.1 or 6 ) of the respective time course R1, R2. The area A1 corresponds, for example, to a thermal cleaning performance of the rinsing water and the area A2 corresponds to a dissolved amount of dirt.

The key figure K is determined on the basis of the respective temporal function value RES, which is given here by the areas A1 and A2. In this example, the key figure K is determined as the sum of the two areas A1, A2, whereby weighting factors a, b are also taken into account, as shown in the following equation (2): $$\mathrm{K}=\mathrm{a}<figure-callout\; id="1"\; label="\cdot \; A"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">\cdot </figure-callout>\mathrm{A}\mathrm{}1+\mathrm{b}\cdot \mathrm{<figure-callout\; id="2"\; label="A"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">A</figure-callout>}2$$

At time t1, the characteristic value K reaches a predetermined threshold value LIM, from which it is concluded, for example, that the items to be washed are clean. Therefore, at this time t1, the washing program can be ended or it can proceed to the next sub-program step of the washing program.

Fig.4 shows a further schematic diagram of a temporal progression R1, R2, R3 of a sensor signal SS over several rinsing program runs with associated rinsing program function value SF (upper diagram) as well as a schematic diagram of a progression of a rinsing program function value SIG1 (lower diagram).

The upper diagram shows the time course R1, R2, R3 of a sensor signal SS, for example of a turbidity sensor, over three wash program runs. The first wash program run begins at time t0 and ends at time t1. The second wash program run begins at time t2 and ends at time t3. The third wash program run begins at time t4 and ends at time t5. The wash program function value SF is the time integral of the respective time course R1, R2, R3, which has the values A1, A2, A3. These values correspond, for example, to the amount of dirt that is removed by the dishwasher 1 in a respective wash program run (see Fig.1 or 6 ) was rinsed off.

The course of the washing program function value SIG1 is formed on the basis of the washing program function values SF; in this example, this corresponds to the sum of the washing program function values SF of the previous washing program runs and is shown in the diagram below. The horizontal axis N shows the washing program runs carried out, the vertical axis Σ shows the value of the course of the washing program function value SIG1. The course of the washing program function value SIG1 corresponds to the total amount of dirt that was washed away by the dishwasher 1. After a predetermined total amount of dirt, which is determined, for example, as a predetermined threshold value LIM, a machine cleaning program is carried out in order to prevent any contamination of components of the dishwasher 1 that could lead to an unhygienic condition and/or a decrease in cleaning performance.

Fig.5 shows two schematic diagrams of a course of washing program function values SIG1, SIG2 for different households H1, H2. The horizontal axis N shows the washing program runs carried out, the vertical axis Σ shows the respective value of the course of the washing program function value SIG1, SIG2. The courses shown are, for example, the course of the washing program function value SF (see Fig.4 ) of a turbidity sensor, as shown by the Fig.4 explained.

This example shows that the triggering of a machine cleaning program based on the course of the washing program function value SIG1, SIG2 can be different for different households H1, H2 if the measured values of the turbidity sensor differ. This can be the case, for example, if in one of the households, in this case household H2, the dishes are pre-rinsed before they are put in the dishwasher, but not in the other household H1. In the upper diagram, the threshold value LIM is already reached after 11 washing program runs, whereas in the lower diagram the threshold value LIM is only reached after 23 washing program runs.

Instead of the course of the washing program function value SIG1, SIG2, the measure determined on the basis of several washing program function values SF, for example a weighted sum of several washing program function values SF, as given in equation (1) can also be used.

Fig.6 shows a schematic block diagram of a system 20 with a dishwasher 1, for example the household dishwasher of Fig.1 , and with an external device 200. The dishwasher 1 comprises a communication unit 101, which is designed here as a mobile radio modem and is coupled to the control device 100. The storage unit 120 is integrated in the control device 100. The external device 200 in this example comprises the determination unit 130 and also has a communication unit 201. A communication connection COM can be established between the two communication units 101, 201. The control device 100 sends, for example, time profiles R1, R2, R3, which were recorded by the sensor unit 110, to the determination unit 130. This determines at least one temporal function value RES and transmits it to the control device 100 via the communication connection COM. In addition, the determination unit 130 can receive a code K (see Fig.3 ), a wash program function value SF (see Fig.4 ), a history of a washing program function value SIG1, SIG2 (see Fig.4 or 5 ) and/or a measurement value and transmit it to the control device 100. The control device 100 carries out a predetermined action, in particular a machine care or cleaning program, depending on the temporal function value RES, the characteristic value K, the washing program function value SF, the course of the washing program function value SIG1, SIG2 and/or the measurement value.

Fig.7 shows a schematic block diagram of an embodiment of a method for operating a dishwasher 1, for example the household dishwasher 1 of Fig.1 or the Fig.6 . In a first step S1, a time course R1, R2, R3 (see Fig.1 , 2 , 3 , 4 or 6 ) at least one sensor signal SS (see Fig. 2, 3 or 4 ) of a washing solution. In a second step S2, the temporal progression R1, R2, R3 of the at least one sensor signal SS is stored. In a third step S3, a temporal function value RES, RES1, RES2 (see Fig.1 , 2 or 6 ) is determined on the basis of the time profile R1, R2, R3 of the at least one sensor signal SS. In a fourth step S4, a predetermined action is carried out depending on the determined temporal function value RES, RES1, RES2. The predetermined action includes adjusting a washing program parameter of a currently running washing program, carrying out a machine cleaning program and/or issuing an information signal to a user of the dishwasher 1.

Fig.8 shows a schematic block diagram of a further embodiment of a method for operating a dishwasher 1, for example the household dishwasher 1 of Fig.1 or the Fig.6 . In a first step S10, the dishwasher 1 is switched on or a washing program is started. In a second step S20, for example, an internal status indicator is queried as to whether a machine cleaning program should be carried out. If this query results in a "logically true" T, a machine cleaning program is carried out S25 or the user is suggested to start one. After the machine cleaning program S25, the program is terminated S50, for example.

If the query results in a "logically false" F, the execution of a rinsing program S30 is started. The rinsing program S30 comprises, for example, the sub-steps S31, S32, S33. The step S31 corresponds to the beginning of a loop that runs continuously during the execution of the rinsing program S30. For example, in the step S31 a time sequence R1, R2, R3 (see Fig.1 , 2 , 3 , 4 or 6 ) of a sensor signal SS (see Fig. 2, 3 , or 4 ) is recorded and stored. In step S32, a temporal function value RES (see Fig.1 , 2 or 6 ) is determined on the basis of the stored time course R1, R2, R3 of the sensor signal SS and compared with a predetermined threshold value LIM (see Fig.3 , 4 or 5 ). If the threshold value LIM is exceeded, for example, a logically true T is output, otherwise a logically false F. In the case of a logically false F, the loop starts again. In the case of a logically true T, the loop is terminated S33, for example, the program then moves on to the next subprogram step.

After the end of the washing program run S30, another query S40 follows, in which, for example, a course of a washing program function value SIG1, SIG2 (see Fig.4 or 5 ) is updated and it is determined whether a threshold value LIM has been exceeded. If this is the case (logically true T), for example, the internal status indicator is activated S45 or another predetermined action is carried out. If this is not the case (logically false F), the washing program run is terminated S50.

Although the present invention has been described using exemplary embodiments, it can be modified in many ways.

Reference symbols used:

1

dishwasher

2

Rinse container

3

door

4

Rinsing chamber

5

Swivel axis

6

Loading opening

7

Floor

8

Ceiling

9

Back wall

10

Side wall

11

Side wall

12

Dishwasher intake

13

Dishwasher intake

14

Dishwasher intake

20

system

100

Control device

101

Communication unit

110

Sensor unit

120

Storage unit

130

Investigation Unit

200

external facility

201

Communication unit

A

Pull-out direction

A1

Integral

A2

Integral

A3

Integral

E

Insertion direction

F

logically wrong

H1

Household

H2

Household

K

Key figure

LIM

Threshold

R1

temporal progression

R2

temporal progression

R3

temporal progression

RES

temporal function value

RES1

temporal function value

RES2

temporal function value

S1

Process step

S2

Process step

S3

Process step

S4

Process step

S10

Process step

S20

Process step

S25

Process step

S30

Process step

S31

Process step

S32

Process step

S33

Process step

S40

Process step

S45

Process step

S50

Process step

SF

Rinse program function value

SIG1

History of the washing program function value

SIG2

History of the washing program function value

SS

Sensor signal

T

logically true

t0

time

t1

time

t2

time

t3

time

t4

time

t5

time

Claims (12)

1. System (20) with a dishwasher (1), preferably a household dishwasher, comprising a control device (100) for carrying out a washing program for washing washware arranged in a washing chamber (4) of the dishwasher (1), a sensor unit (110) for detecting a time curve (R1, R2, R3) of at least one sensor signal (SS) of a washing liquor and for outputting the detected time curve (R1, R2, R3) of the at least one sensor signal (SS), a memory unit (120) for storing the time curve (R1, R2, R3) of the at least one sensor signal (SS) and an ascertaining unit (130) for ascertaining a temporal functional value (RES, RES1, RES2) on the basis of the time curve (R1, R2, R3) of the at least one sensor signal (SS), wherein the control device (100) is designed to carry out a specified action as a function of the temporal functional value (RES, RES1, RES2), wherein the ascertaining unit (130) is designed to ascertain a washing program functional value (SF) as a function of the stored time curve (R1, R2, R3) of the at least one sensor signal (SS) for a washing program cycle, to store the washing program functional value (SF) and to ascertain a curve of the washing program functional value (SIG1, SIG2) on the basis of the washing program functional value (SF) over a plurality of washing program cycles, wherein the control device (100) is designed to carry out the specified action as a function of the ascertained curve of the washing program functional value (SIG1, SIG2), characterised in that the sensor unit (110) has at least two of a turbidity sensor, a conductivity sensor, a temperature sensor and a filter soiling sensor, wherein the ascertaining unit (130) is designed to ascertain the respective washing program functional value (SF) as a function of the stored time curve (R1, R2, R3) of the respective signal of the at least two sensor signals (SS) for a washing program cycle, to store the respective value of the at least two washing program functional values (SF) and to ascertain a statistic on the basis of the respective curve of the at least two washing program functional values (SF) over a plurality of washing program cycles, wherein the control device (100) is designed to carry out the specified action as a function of the ascertained statistic.
2. System according to claim 1, characterised in that the sensor unit (110) comprises a turbidity sensor for detecting a turbidity of the washing liquor, preferably an optical turbidity sensor, and/or a conductivity sensor for detecting a conductivity of the washing liquor, preferably a spectroscopic impedance sensor, and/or a temperature sensor for detecting a temperature of the washing liquor.
3. System according to claim 1, characterised in that the sensor unit (110) comprises a turbidity sensor for detecting the turbidity of the washing liquor, preferably an optical turbidity sensor, a conductivity sensor for detecting a conductivity of the washing liquor, preferably a spectroscopic impedance sensor, and a temperature sensor for detecting the temperature of the washing liquor.
4. System according to one of claims 1 - 3, characterised in that the sensor unit (110) comprises the filter soiling sensor which is designed to detect a degree of soiling of a filter arranged in the dishwasher (1) and to output the detected degree of soiling as a further sensor signal (SS).
5. System according to one of claims 1 - 4, characterised in that the ascertaining unit (130) is designed to integrate the time curve (R1, R2, R3) of at least one of the sensor signals (SS) to ascertain an integral value (A1, A2, A3), wherein the control device (100) is designed to carry out the specified action as a function of the ascertained integral value (A1, A2, A3).
6. System according to claim 5, characterised in that the ascertaining unit (130) is designed to integrate the respective time curve (R1, R2, R3) of the at least two sensor signals (SS) and to ascertain a key figure (K) on the basis of the at least one two integral values (A1, A2, A3), wherein the control device (100) is designed to carry out the specified action as a function of the ascertained key figure (K).
7. The system according to one of claims 1 - 6, characterised in that the ascertaining unit (130) is designed to differentiate the time curve (R1, R2, R3) of at least one of the sensor signals (SS) to ascertain a differential value, wherein the control device (100) is designed to carry out the specified action as a function of the ascertained differential value.
8. System according to one of claims 1 - 7, characterised in that the control device (100) is designed to carry out a machine care program and/or a filter cleaning program as a function of the temporal functional value (RES, RES1, RES2) and/or the curve of the washing program functional value (SIG1, SIG2).
9. System according to one of claims 1 - 8, characterised in that the control device (100) is designed to adapt the current washing program, in particular for shortening a sub-program step of the current washing program, as a function of the temporal functional value (RES RES1, RES2).
10. System according to one of claims 1 - 9, characterised by a facility (200) which is external to the dishwasher (1) and which comprises the ascertaining unit (130), wherein the dishwasher (1) and the external facility (200) in each case have a communication unit (101, 201) for bidirectional communication.
11. Method for operating a dishwasher (1), preferably a household dishwasher, with a control device (100) for carrying out a washing program for washing washware arranged in a washing chamber (4) of the dishwasher (1), the method comprising:

    detecting (S1) a time curve (R1, R2, R3) of at least one sensor signal (SS) of a washing liquor,

    storing (S2) the time curve (R1, R2, R3) of the at least one sensor signal (SS),

    ascertaining (S3) a temporal functional value (RES RES1, RES2) on the basis of the time curve (R1, R2, R3) of the at least one sensor signal (SS) and

    carrying out (S4) a specified action as a function of the temporal functional value (RES RES1, RES2),

    wherein a washing program functional value (SF) is ascertained as a function of the stored time curve (R1, R2, R3) of the at least one sensor signal (SS) for a washing program cycle, the washing program functional value (SF) is stored and a curve of the washing program functional value (SIG1, SIG2) is ascertained on the basis of the washing program functional value (SF) over a plurality of washing program cycles, wherein the specified action is carried out as a function of the ascertained curve of the washing program functional value (SIG1, SIG2), characterised in that the sensor unit (110) has at least two of a turbidity sensor, a conductivity sensor, a temperature sensor and a filter soiling sensor, wherein the respective washing program functional value (SF) is ascertained as a function of the stored time curve (R1, R2, R3) of the respective signal of the at least two sensor signals (SS) for a washing program cycle, the respective value of the at least two washing program functional values (SF) is stored and a statistic is ascertained on the basis of the respective curve of the at least two washing program functional values (SF) over a plurality of washing program cycles, and the specified action is carried out as a function of the ascertained statistic.
12. Computer program product comprising commands which, when the program is executed by a computer, cause the computer to execute the method according to claim 11.

Images