Method for proving the loading of a rotary drum in a laundry treatment machine and corresponding laundry treatment machine

Abstract

The present invention relates to a method for proving the loading of a rotary drum in a laundry processor. The sensor device includes a pair of electrodes for contacting the laundry in the drum, an evaluation device, a line connecting the evaluation device to the electrodes, and a counter provided in the evaluation device. In this method: the evaluation device sets the counter to zero upon startup; the evaluation device receives a series of resistance measurement values from the electrodes during a detection period; the evaluation device compares each resistance measurement value with a threshold value, and if the resistance measurement value is less than the threshold value, the counter is incremented by 1, and if the resistance measurement value is greater than or equal to the threshold value, the counter remains unchanged; the evaluation device compares the value of the counter with a first limit value, and if the value is greater than the first limit value, the proof of loading is determined to be "positive", and if the value is less than or equal to the first limit value, the proof is determined to be "negative". The present invention also relates to a laundry processor for performing this method.

Description

Technical field

[0001] The invention relates to a method for proving the loading of a rotating drum in a laundry processor by a moist laundry within a detection time period starting from the start of operation of the laundry processor and by means of a sensor device, the sensor device including a pair of electrodes for contacting the laundry in the drum, an evaluation device, a line connecting the evaluation device to the electrodes, and a counter provided in the evaluation device.

[0002] The invention further relates to a laundry processor including a rotatable drum for receiving moist laundry and a sensor device, the sensor device including a pair of electrodes for contacting the laundry in the drum, an evaluation device, a line connecting the evaluation device to the electrodes, and a counter provided in the evaluation device. Background art

[0003] A method for operating a laundry dryer is known from EP 2 013 403 A1, in which a sensor circuit is provided, which generates a pulse signal from the contact with the moist laundry. Here, the voltage depending on the resistance of the contact with the laundry is measured by electrodes and fed to a comparator, and depending on whether the measured voltage is higher or lower than a pre-given threshold value, the comparator generates a pulse signal of a pre-given high voltage or zero. Then it is fed to a counter, by means of which the average frequency of the pulse signal is determined. This average frequency is used as an indication of the drying of the laundry. The absence of the pulse signal during the operation of the laundry dryer is used as an indication of a functional failure.

[0004] A laundry processor of the type defined at the beginning, in particular a laundry dryer, is known from US 4,385,452 A. During the drying process of the laundry in the laundry dryer, a series of voltage measurements are carried out on the laundry bridging the electrodes by means of the electrodes. When a given number of respectively successively carried out voltage measurements provide results that can relate to the humidity of the laundry, a counter that is incremented for pulses of a constant frequency is reset to zero. When the counter exceeds a pre-determined limit value, the drying process ends.

[0005] In addition to identifying possible functional faults of a laundry treatment machine, it is also meaningful to check a laundry treatment machine that has been put into operation and has been working without problems so far: whether it has actually been loaded with laundry to be treated. In the case where the laundry treatment machine is used as a laundry dryer, this particularly means checking whether the laundry treatment machine is loaded with a reasonable amount of laundry with a reasonable initial humidity. If the laundry treatment machine has a drum that rotates during operation and moves the laundry relative to each other, the mechanical power required to rotate the drum can be measured and compared with a threshold value, where a value below the threshold can be used to infer a lack of loading. Existing electrodes can also be used to measure the humidity of the laundry during the drying process. However, here, due to the changing contact between the electrodes and the laundry, on the one hand, the measurement accuracy and on the other hand, the external interference signals that must be eliminated from the measured values by appropriate filtering measures can be strongly affected. In particular, when there is a relatively small batch of laundry with only a small amount of humidity in the laundry treatment machine, the filtering measures may affect the measurement accuracy. Summary of the Invention

[0006] Accordingly, the object of the present invention is to provide an effective method for proving the loading of a rotating drum in a laundry treatment machine with damp laundry and a laundry treatment machine having the corresponding ability.

[0007] To solve this object, a method is provided which is used to prove the loading of a rotating drum in a laundry treatment machine with damp laundry within a detection period starting from the start of operation of the laundry treatment machine and by means of a sensor device. The sensor device includes a pair of electrodes for contacting the laundry in the drum, an evaluation device, a line connecting the evaluation device to the electrodes, and a counter provided in the evaluation device. In this method, the evaluation device sets the counter to zero upon startup, and then the evaluation device receives a series of resistance measurement values from the electrodes during the detection period. The evaluation device compares each resistance measurement value with a threshold value, and if the resistance measurement value is less than the threshold value, the counter is incremented by 1, while if the resistance measurement value is greater than or equal to the threshold value, the counter remains unchanged. The evaluation device also compares the value of the counter with a first limit value, and if the value is greater than the first limit value, the proof of loading is determined as "positive", while if the value is less than or equal to the first limit value, the proof of loading is determined as "negative".

[0008] The method determines the degree to which the resistance measurement data is below the threshold, and thus can tolerate noise in the resistance measurement values relatively well, where most of this noise has been generated by the laundry in motion in the rotating drum bridging the electrodes in a fluctuating manner. Therefore, no laborious filtering measures need to be taken for the signals collected from the electrodes. Thus, within the scope of proving (whether there is a batch of laundry to be dried in the drum) before the actual drying process, filtering measures that are used in the conventional application scope to determine the residual humidity in the dried laundry batch can be dispensed with.

[0009] The method can also be completed within a particularly short detection time period, and thus helps to avoid using energy for a laundry processor that is operating uselessly, as well as avoid operating sensitive components of the laundry processor, such as a heat pump.

[0010] The method can also achieve relatively high measurement accuracy and reliability in such a way that very small and slightly moist laundry batches can also be detected. In a suitable design, in a laundry processor designed for drying laundry batches with a dry weight of 5 kg to 10 kg and a humidity of 50% (i.e., a water content with a weight of 50% of the dry weight of the laundry), a laundry batch with a humidity of 10% and a dry weight of 0.1 kg (corresponding to a small hand towel used to dry wet hands) can be detected. This also makes it possible to define and provide an automatically performed drying process for such small laundry batches in a laundry processor with the corresponding capabilities.

[0011] The method can be applied to existing laundry processors with less effort, and in particular, it can be fully implemented or at least largely implemented by correspondingly changing the control software. The possible changes to the hardware mainly involve turning on and off the filter for the signals to be collected by the electrodes, and the filter is implemented in hardware.

[0012] In a preferred expansion of the method according to the invention, the evaluation device receives first raw measurement values from the electrodes at a measurement frequency, and combines respectively a quantity n1 of directly successive first raw measurement values into corresponding second raw measurement values. Thus, the series of second raw measurement values thus obtained can be applied to the method as a series of resistance measurement values with or without further processing.

[0013] Further preferably, the measurement frequency is approximately 800 Hz.

[0014] Even further preferably, when combining each second raw measurement value, the average value of the corresponding first raw measurement values is formed, and in addition, the maximum first raw measurement value and the minimum first raw measurement value in the corresponding raw measurement values are not considered.

[0015] Preferably, the number n1 of the first raw measurements to be combined into the second raw measurement is equal to 8.

[0016] One preferred expansion of the present invention provides that each second raw measurement is a resistance measurement, that is to say the resistance measurement is directly and without further processing applied in a further method according to the invention. This is not very complex and is fault-proof. However, at a measurement frequency of about 800 Hz, the second raw measurements are generated at a frequency of 100 Hz, which in the case of a detection time of the order of one minute results in 6000 or several times that number of individual data to be processed and requires a corresponding size of counter.

[0017] An expansion of the invention in place of the previous expansion provides that the evaluation device forms each resistance measurement as the minimum value of a number n2 of second raw measurements that follow one another in time. Thereby the frequency (at which the resistance measurements are generated) is further reduced and the number of data to be processed is reduced. The second number n2 is preferably equal to 100, corresponding to a 100-fold reduction in the data to be processed. In the case of a preferred measurement frequency of 800 Hz and an equally preferred number n1 of 8, this results in one resistance measurement being generated per second of the detection time and in the case of a detection time of one minute the counter only having to be able to count up to 60, corresponding to a counter size of six bits per minute of detection time.

[0018] According to another preferred expansion of the invention, the evaluation device determines the threshold value for each resistance measurement from the average value of each resistance measurement received since start-up and subtracts a distance value from this average value, where the distance value is greater than or equal to zero. Thus, a variable floating threshold is defined and applied, which is derived from the resistance measurements themselves and can thus be adapted accordingly to the respective individual case. This makes it superfluous to determine and define corresponding and generally applicable enough threshold values in the context of the development of a laundry care machine to be equipped according to the invention, and also increases the precision of the proof in individual cases.

[0019] A preferred additional expansion of the expansion of the invention described in the previous paragraphs provides that the evaluation device compares the average value finally formed at the end of the detection period with a second limit value, and if the finally formed average value is less than the second limit value, determines the loaded proof as "positive", and if the finally formed average value is greater than or equal to the second limit value, determines the proof as "negative". Thus, an additional criterion is introduced for the desired proof and the precision of the method is further increased.

[0020] Particularly preferably, for the application of the present invention, the detection time period is determined to be approximately one minute after commissioning. Thereby, a high precision that is advantageously used for the application of the method is achieved, and the goal of "avoiding unnecessary operation of the laundry treatment appliance" is promoted. Thus, the present invention only requires approximately a quarter of the time required in a conventional method for proving the loading of a laundry care machine.

[0021] To solve this task, a laundry treatment machine is also provided, which includes a rotatable drum for receiving damp laundry and a sensor device. The sensor device includes a pair of electrodes for contacting the laundry in the drum, an evaluation device, a line connecting the evaluation device to the electrodes, and a counter provided in the evaluation device. In this laundry treatment machine, the evaluation device is arranged to perform the method according to the present invention as described herein.

[0022] The laundry treatment machine according to the present invention is preferably a laundry dryer.

[0023] The laundry treatment machine according to the present invention is preferably used to process a batch of laundry with a dry weight between 5 kg and 10 kg, which is common in laundry treatment machines for private households. Further preferably, the laundry treatment machine is determined to dry the laundry put into the drum with a residual humidity of approximately 50% within a time period of approximately 2 hours. Thus, in this laundry treatment machine, the detection time period for proving the loading according to the present invention is less than 1% of the total time required for the drying process. Description of the Drawings

[0024] Embodiments of the present invention will be described below with reference to the drawings. The drawings show:

[0025] Figure 1 A schematic diagram of a laundry care machine according to the present invention;

[0026] Figure 2 A flowchart of a first embodiment of the method;

[0027] Figure 3 A flowchart of a second embodiment of the method;

[0028] Figure 4 A flowchart of a third embodiment of the method. Detailed Description

[0029] Figure 1The diagram shows a laundry processor 1, which includes a drum 2 that can rotate about an axis 3 and is configured to accommodate damp laundry 4. The laundry processor 1 also includes sensor devices 5, 6, 7, 8, which include a pair of electrodes 5 for contacting the laundry 4 in the drum 2, an evaluation device 6, a line 7 connecting the evaluation device 6 to the electrodes, and a counter 8 provided in the evaluation device 6. The line 7 is mainly shown only as a line, but in reality it should of course be two-pole.

[0030] The laundry processor 1 is a laundry dryer for use in private households and for processing batches of laundry 4 with a dry weight between 5 kg and 10 kg. In particular, it is provided that the laundry 4 is placed in the drum 2 with a residual humidity of approximately 50%, and is dried to a residual humidity of substantially zero within a period of approximately two hours.

[0031] According to conventional practice, the sensor devices 5, 6, 7, 8 are used to control the drying process of the damp laundry 4 in the drum 2, where resistance measurements are carried out with the aid of the electrodes 5, from which the residual humidity contained in the laundry 4 can be inferred: the lower the resistance formed by the laundry 4 between the electrodes 5, the greater the residual humidity. However, this measured resistance is subject to strong fluctuations, which are caused by the fact that the contact between the electrodes 5 and the laundry 4 is subject to strong fluctuations due to their movement in the rotating drum 2. Interference signals also have an impact, which penetrate into the evaluation device 6 due to the antenna effect of the electrodes 5 together with their line 7 and are superimposed on the measured resistance values. Therefore, a filter needs to be connected upstream of the humidity measurement device 11 in the evaluation device 6, which is symbolically represented here by a first filter 9 and a second filter 10. The second filter 10 among them is only assigned to the humidity measurement device 11. The humidity measurement device 11 is assigned a second display device 13, which is schematically shown as a lamp.

[0032] In addition, the evaluation device 6 has a counter 8, and the measured values from the electrodes 5 are only fed to the counter 8 after being filtered by the first filter 9, where the filtering is carried out as follows: the evaluation device 6 first receives from the electrodes 5 a first raw measurement value r1 with a pre-given, preferably approximately 800 Hz measurement frequency j and combines a first quantity n1 of directly successive first raw measurement values r1 j into a corresponding second raw measurement value r2 j . When combining each second raw measurement value r2 j , an average value of the corresponding first raw measurement values r1 j is formed, where the corresponding raw measurement values r1 jthe maximum first raw measurement value and the minimum first raw measurement value therein. The first quantity n1 is preferably equal to 8. The counter 8 is assigned to a first display device 12, which is in turn schematically shown as a lamp.

[0033] Each second raw measurement value r2 thus obtained j can easily be regarded as and used as a resistance measurement value r i . However, at a measurement frequency of approximately 800 Hz, the frequency of the second raw measurement value r2 thus obtained j is still very high at 100 Hz. If the detection time period t D is specified as one minute, a total of approximately 6000 second raw measurement values r2 j occur, which require a counter 8 with a corresponding capacity, or a counter 8 as follows: The counter is limited in its capacity at a sufficient maximum size and operates such that when it reaches the maximum count value, it stops and is not reset to zero, for example, due to a regular overflow. Therefore, it makes sense to further reduce the number of resistance measurement values r i . For this purpose, the evaluation device 6 can form each resistance measurement value r i as the minimum value of a second quantity n2 of second raw measurement values r2 j successive in time, where the second quantity n2 is equal to 100. Thus, in the example discussed here, the number of resistance measurement values to be evaluated per detection time period is reduced from 6000 to 60.

[0034] Shown in Figure 2 is a method in the form of a flowchart for proving the loading of a wet laundry 4 on a rotary drum 2 in a laundry processor 1 within a detection time period t D starting from the start of operation of the laundry processor 1 and by means of sensor devices 5, 6, 7, 8, the sensor devices including a pair of electrodes 5 for contacting the laundry 4 in the drum 2, an evaluation device 6, a line 7 connecting the evaluation device 6 to the electrodes 5, and a counter 8 provided in the evaluation device 6. The method proceeds in particular as follows: The evaluation device 6 sets the counter 8 to zero upon startup. During the detection time period t D , the evaluation device 6 receives a series of resistance measurement values r i from the electrodes 5. The evaluation device 6 compares each resistance measurement value r i with a threshold value s; if the resistance measurement value r i is less than the threshold value s, the counter 8 is incremented by one; if the resistance measurement value r iIf the value z is greater than or equal to the threshold value, the counter 8 is unchanged. Finally, the evaluation device 6 compares the value z of the counter 8 with the first limit value g1 and determines the proof of loading as "positive" if the value z is greater than the first limit value g1, and as "negative" if the value z is less than the first limit value g1 or equal to the first limit value. To this end, the counting parameter i is first set to zero, and the time parameter t and the value z of the counter 8 are also set to zero. With each reception of the resistance measurement value r i , the counting parameter i increases by 1. Then the resistance measurement value r i The comparison is made with the threshold value s and, if necessary, the counter 8 is increased by 1. This is repeated in a cyclic manner until the time parameter t exceeds the detection time period t D The value of the counter 8 is then compared with the first limit value g1 and the proof is determined to be "positive" or "negative" accordingly, as in Figure 2 As indicated by positive and negative signs in .

[0035] Figures 3 to 4 The flow chart of the preferred embodiment of the method is shown. j Processed as the second original measurement value r2 j As described in detail above, such steps correspond to Figure 1 The filtering of the first filter 9 is shown in FIG.

[0036] However, Figure 3 An embodiment of the method is shown, in which the evaluation device 6 calculates each resistance measurement value r i Second raw measured values r2 that are formed as a second number n2 of temporally successive second raw measured values r2 j The minimum value of , wherein the second number can be equal to 100. Therefore, each detection time period t D The number of resistance measurements to be evaluated can be reduced from 6000 to 60. Figure 3 For this purpose, a second counting parameter j and a flag f are used, both of which are initially set to zero. The second counting parameter j is used to identify the detection time period t divided into n2 equal-length subintervals. D Time point t j-1 With t j and determine whether there is a resistance measurement value r less than the threshold value s in each of these time intervals. i If this is the case, the flag is set to 1. After each subinterval has expired, it is only checked whether the flag is equal to 1. If so, the counter 8 is increased by one. Figure 2 That way, the certification is done at the end of the probing period.

[0037] In accordance withFigure 4 In the method, the evaluation device 6 measures the value r for each resistance i Each resistance measurement value r received since commissioning i The average value m i And by the average value m from this value i Subtract a distance value a to determine the floating threshold s i , wherein the distance value a is greater than or equal to zero. The threshold value to be applied in each case is therefore determined by the data obtained in the method itself (in addition to the possibly applied distance value a) and is thus adapted to the individual case. Figure 4 No direct description of the floating (gleitend) mean m i Instead, this is only obtained by the expression m i+1 (m i ) to express the correlation between successive floating averages. D In addition to the proof criterion that the value z of the counter 8 exceeds the first limit value at the end of the detection period, an additional proof criterion is used. This is done as follows: the evaluation device 6 will D The final average value m at the end of the term i is compared with the second limit value g2 and if the mean value m finally formed is i If the average value is less than the second limit value g2, the certificate of loading is determined to be "positive", and if the last formed average value is greater than or equal to the second limit value g2, the certificate is determined to be "negative".

[0038] The main advantage of the present invention is that the detection time period t D This is determined to be approximately one minute after being put into operation, thereby reducing the detection time period required for conventional methods by 75%. Thus, the present invention enables significantly more accurate verification of the load in the laundry care machine in less time than conventional practice.

[0039] Reference Signs List

[0040] 1 laundry processing machine

[0041] 2 rollers

[0042] 3 axis

[0043] 4 laundry

[0044] 5 electrodes

[0045] 6 Evaluation device

[0046] 7 lines

[0047] 8 counters

[0048] 9 First filter

[0049] 10 Second filter

[0050] 11 Humidity measuring device

[0051] 12 First display device

[0052] 13 Second display device

[0053] a Distance value

[0054] f Flag

[0055] g1 First limit value

[0056] g2 Second limit value

[0057] m i Floating average value

[0058] n1 First quantity

[0059] n2 Second quantity

[0060] r1 j First original measurement value

[0061] r2 j Second original measurement value

[0062] s Threshold value

[0063] s i Floating threshold value

[0064] t Time

[0065] t D Detection time period

[0066] z Value of counter 8

Claims

1. A method for proving the loading of a wet laundry (4) onto a rotary drum (2) in a laundry processor (1) within a detection time period (t D ) starting from the start of operation of the self - laundry processor (1) and by means of a sensor device (5, 6, 7, 8), the sensor device comprising a pair of electrodes (5) for contacting the laundry (4) in the drum (2), an evaluation device (6), a line (7) connecting the evaluation device (6) to the electrodes (5), and a counter (8) provided in the evaluation device (6), in which method: a) The evaluation device (6) sets the counter (8) to zero upon said commissioning; b) The evaluation device (6) receives a series of resistance measurements (r D ) from the electrode (5) during the detection time period (t i ); c) The evaluation device (6) compares each resistance measurement value (r i ) with a threshold value (s), and if the resistance measurement value (r i ) is less than the threshold value (s), the counter (8) is incremented by 1, and if the resistance measurement value (r i ) is greater than or equal to the threshold value (s), the counter (8) remains unchanged; d) The evaluation device (6) compares the value (z) of the counter (8) with a first limit value (g1), and if the value (z) is greater than the first limit value (g1), determines the loaded proof as "positive", and if the value (z) is less than or equal to the first limit value (g1), determines the proof as "negative".

2. The method according to claim 1, wherein, The evaluation device (6) receives first raw measurement values (r1 j ) from the electrodes at a measurement frequency and combines a first number (n1) of directly successive first raw measurement values (r1 j ) into corresponding second raw measurement values (r2 j ).

3. The method according to claim 2, wherein, The measurement frequency is 800 Hz.

4. The method according to one of claims 2 and 3, wherein, When combining each second raw measurement (r2 j ), the average value of the corresponding first raw measurement (r1 j ) is formed, where the maximum and minimum first raw measurements in the corresponding raw measurement (r1 j ) are not considered.

5. The method according to claim 2, wherein, The first quantity (n1) is equal to 8.

6. The method according to claim 2, wherein, Each second original measurement value (r2 j ) is a resistance measurement value (r i ).

7. The method according to claim 2, wherein, The evaluation device (6) forms each resistance measurement value (r i ) as the minimum value of a second quantity (n2) of temporally successive second raw measurement values (r2 j ).

8. The method according to claim 7, wherein The second quantity (n2) is equal to 100.

9. The method according to any one of claims 6 to 8, wherein The evaluation device (6) determines, for each resistance measurement value (r i ), a floating threshold (s i ) from the mean value (m i ) of each resistance measurement value (r i ) received since the start of operation, and subtracting the distance value (a) from the mean value (m i ), where the distance value (a) is greater than or equal to zero.

10. The method according to claim 9, wherein The evaluation device (6) compares the mean value (m D ) finally formed at the expiration of the detection time period (t i ) with a second limit value (g2), and if the finally formed mean value (m i ) is less than the second limit value (g2), the loaded proof is determined to be "positive", and if the finally formed mean value is greater than or equal to the second limit value (g2), the proof is determined to be "negative".

11. The method according to claim 1, wherein, The detection time period (t D ) is determined to be one minute after being put into operation.

12. A laundry processor (1) comprising a rotatable drum (2) for receiving a damp laundry (4) and a sensor device (5, 6, 7, 8), the sensor device comprising a pair of electrodes (5) for contacting the laundry (4) in the drum (2), an evaluation device (6), a line (7) connecting the evaluation device (6) to the electrodes (5), and a counter (8) provided in the evaluation device (6), characterized in that, The evaluation device (6) is set up to carry out the method according to one of the preceding claims.

13. The laundry processor (1) according to claim 12, wherein the laundry processor is a laundry dryer.

14. The laundry processor (1) according to one of claims 12 and 13, wherein the laundry processor is determined for processing batches of laundry (3) with a dry weight between 5 kg and 10 kg.

15. The laundry processor (1) according to claim 14, wherein the laundry processor is determined for drying laundry (3) introduced into the drum (2) with a residual humidity of 50% over a period of 2 hours.

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