EP2548490A2 - Method for monitoring the fill level of a vacuum cleaner and vacuum cleaner for carrying out such a method - Google Patents

Abstract

The method involves receiving data for a measure for an actual low pressure and for a measure of an actual volume flow. The data are stored in a storage for a volume flow-dependent characteristic curve. An operating point is determined on the characteristic curve based on the actual volume flow. An instantaneous filling level of a vacuum cleaner (1) is determined based on the actual low pressure and the low pressure related to the operating point on the characteristic curve. Independent claims are included for the following: (1) a vacuum cleaner with a control unit; and (2) a computer program with program code instructions.

Description

The invention relates to a method for level monitoring or level indicator - hereinafter collectively referred to as level monitoring - in a vacuum cleaner and a working vacuum cleaner according to the method.

A level monitoring for a dust bag of a vacuum cleaner is known per se with vacuum cleaners. In a known and commonly used embodiment, the differential pressure between the dust chamber and the environment is displayed with a mechanical spring gauge. The higher the differential pressure, the greater the spring travel and the associated display. However, today's dust bag level monitoring often works only to an unsatisfactory extent. The display is only slightly similar to the actual filling level. Rather, the display of the respective state of the floor nozzle depends (placed, raised, sealed) and linked to the prevailing negative pressure according to the existing load, as can be easily checked by throttling the suction hose with an empty bag, if then the level monitoring a full or substantially full dust bag signals. In addition to the very inaccurate mechanical display, the previous level monitoring has a significant hysteresis and there is no sufficient correlation to the actual Staubbeutelfüllgrad. In a design by means of mechanical spring still significant component tolerances are added that do not allow comparable statements between the vacuum cleaners of a series. Furthermore, depending on the level of performance selected, the display will respond by indicating, at low power settings, a level of filling that appears to permit further operation and may result in bursting of the dustbag due to overfilling or by prompting the user to change Dust bag is asked, although he is not even necessary.

Furthermore, the embodiment described above is a permanent leakage, which has an adverse effect from an energetic point of view and reduces the suction power available at the floor nozzle. This loss of air and suction was tolerated in previous vacuum cleaners with high recording power. Based on future legal requirements and in the course of a general improvement in efficiency, this suction power loss is no longer acceptable, especially with regard to the further reductions in recording power in the future.

The EP 0 365 191 A describes a solution in which, during operation of the vacuum cleaner with a first pressure switch, which responds to three discrete pressure levels, a first, discrete pressure reading and a second pressure switch, which also responds to three discrete, but different pressure levels, recorded a second, discrete pressure reading becomes. From the discrete pressure measured value recorded by the second pressure switch, it is intended to be possible to determine a respectively associated volume flow without the volume flow playing a role in the evaluation described below. In fact, certain pressure levels detectable by the first and second pressure sensors are monitored. The monitoring and monitoring thresholds are or are dependent on different power settings (100%, 70%, 60% and 50%) of the suction fan. A full dust bag should then be recognized by the fact that both the first and the second pressure sensor indicates a low or medium pressure level. The qualification of a low or medium pressure level is based on the power setting. The result describes the EP 0 365 191 A that is, a combination of the pressure levels displayed by the two pressure sensors with variable threshold values that depend on the respective power setting. This solution may be useful for detecting extreme situations such as a filled dust bag, but does not permit a continuous level indication.

In the DE 88 15 620 U is driven with the exhaust air flow of a suction fan, an air turbine and detects their speed. The air turbine acts as a volumetric flow sensor and with a measured value supplied by it, a determination of operating conditions of the vacuum cleaner, for example, the determination of the Staubbeutelfüllgrads be possible. The DE 88 15 620 U also mentions the possibility of combining the volumetric flow measured values supplied by the air turbine with measured values of a membrane pressure switch in order to be able to recognize operating states which can not be unambiguously identified solely on the basis of a volumetric flow measured value.

If the DE 88 15 620 U mentions that even a quasi-continuous level indicator should be possible on the basis of the measured value recorded for the volume flow, this can only be possible based on the volume flow only if the suction fan is operated with exactly one and also constant power. Even if the approach in the DE 88 15 620 U is extended to different power settings, there is only a comparison of the respective volumetric flow measurement with power setting dependent limits.

An object of the invention is accordingly to provide a further method for level control in a vacuum cleaner, in particular a method for Level monitoring, which avoids the disadvantages outlined above or at least reduces their effects.

This object is achieved with the features of claims 1 or 2. For this purpose, in a method for level monitoring in a vacuum cleaner is initially provided that the vacuum cleaner in operation with electrical power and a negative pressure and a flow causing drive unit comprising an electric motor and that during operation data for a measure of an actual negative pressure and for a Measure for an actual volume flow, so in particular corresponding measured values, recorded and related signals, in particular analog signals, or digitized signals covering a wide detection range, are generated.

In the method according to claim 1 is further provided that data for at least one volume flow-dependent characteristic are stored in a memory. Based on the actual volume flow then an operating point on the at least one characteristic is determined. On the basis of the actual negative pressure and the operating point on the characteristic associated negative pressure is finally determined as the current level of the vacuum cleaner filling level of the dust bag or bagless vacuum cleaners a degree of its dust collector.

Neither the DE 88 15 620 U still the EP 0 365 191 A disclose the use of a volume flow dependent characteristic. In the DE 88 15 620 U are one or more volume flow limits fixed by hardware implemented limit or window discriminators. Even with extension of the approach in the DE 88 15 620 U different power settings result in power setting dependent limits only, but no volumetric flow dependent characteristics. In the EP 0 365 191 A Although the consideration of different power settings is mentioned, but here too the respective power setting leads only to the use of different limit values. In addition, the detection of a filled dust bag is based on two discrete pressure readings, so that here no volume flow-dependent characteristic is used. Furthermore, the prior art according to the DE 88 15 620 U or EP 0 365 191 A It is also foreign to consider volumetric flow and pressure measured values on the basis of the characteristic curve.

In the method according to claim 2 is alternatively or additionally provided that data for at least one volume flow-dependent characteristic are stored in the memory for certain level situations. On the basis of the actual negative pressure on the one hand and the actual volume flow on the other hand then an instantaneous operating point is determined. The determined instantaneous operating point then becomes the one or more Characteristics are related. Thus, at least one characteristic which is best suited to the instantaneous operating point is selected from the one or more characteristic curves. The current level of the vacuum cleaner, ie a degree of filling of its dust bag or bagless vacuum cleaners a degree of its dust collection, then results from the selected characteristic (s) and the level situation for which this was originally recorded (s).

Again, the above applies, according to which from the prior art according to the DE 88 15 620 U or EP 0 365 191 A no volume flow-dependent characteristics are known. Furthermore, the prior art according to the DE 88 15 620 U or EP 0 365 191 A It is also foreign to look at the volumetric flow and pressure readings to select one or more characteristics recorded for specific level situations.

The data for the volume-flow-dependent characteristic curve (s) may be data for point quantities for describing such characteristics, but also algorithms for simulating such characteristics. By the method of volume flow is based, different floor coverings and load conditions of the vacuum cleaner can be largely compensated. Both methods can also be combined, so that a displayed level results as an average or otherwise suitably weighted combinations of both detected levels.

In an advantageous embodiment, to further optimize the method, the air temperature can be included in the calculation of the air power to allow a higher accuracy.

Advantageous embodiments of the invention are the subject of the dependent claims. The relationships used here indicate the further development of the subject matter of an independent claim by the features of the respective subclaim. They may also contain independent inventions having a design independent of the objects of the preceding claims and are not to be understood as a waiver of obtaining independent, objective protection of their characteristics. Furthermore, with a view to an interpretation of the claims in a closer specification of a feature in a subordinate claim, it is to be assumed that such a restriction does not exist in the respective preceding claims.

In one embodiment of the method, by relating the determined instantaneous operating point to the characteristic curves and selecting from the characteristic curves two or more characteristics which best match the instantaneous operating point, and Current level of the vacuum cleaner on the basis of the selected characteristics and an interpolation of the level situations for which they were originally recorded, is an even more accurate, quasi-continuous determination of the level and based on an even more accurate level monitoring possible.

To inform a user of the vacuum cleaner on the level is an optical display device into consideration, with which the respective current level is displayed or brought in any other form for display. With the accuracy of the level monitoring according to the method proposed here, a level indicator with an optical display makes sense because the current level, e.g. as a percentage, as a bar and the like can be displayed. An optical display device is also advantageous because it - in particular switchable or automatically alternating - also for displaying other operating parameters of the vacuum cleaner is used, for example, to represent a residual capacity of a battery for powering the vacuum cleaner.

In one provided for displaying a plurality of operating parameters of the vacuum cleaner optical display device, an embodiment is that at a level above a predetermined or predetermined threshold, the display is automatically switched to represent the level, so that the user of the vacuum cleaner on the changed situation with respect to the level of the Dust bag is alerted.

A further embodiment of the method is characterized in that at a filling level above a predetermined or predeterminable limit value for information or as a warning signal, a message is sent to the user of the vacuum cleaner. The message can be a visual or audible message or a combined visual and audible message. Furthermore, comes into consideration, instead of o.g. Limit value to provide a first and a second limit, wherein the achievement of the first limit value, e.g. an optical message and the achievement of the second limit, e.g. at least an acoustic message triggers.

In a further embodiment, it is provided that at a level above a predetermined or predefinable alarm levels, the electric power absorbed by the drive unit is reduced, so that there is no longer any possibility that the level reached escapes the attention of the user of the vacuum cleaner. The user is informed that the dust bag has reached its final capacity or will soon reach it and only a limited operation in the manner of an emergency operation is possible. In addition, a reduction of the amount of dust that can be absorbed in a unit of time is achieved by the reduction of the absorbed electrical power, so that the risk of bursting of the dust bag is reduced. Regarding the reduction of electric Performance is a reduction to a predetermined or specifiable level into consideration, for example, in a control unit of the vacuum cleaner fixed or variable can be stored.

For even more extensive automatic user information can be a message at a not or not completely closed dust chamber closure and / or a message when not inserted dust bag. In addition or as an alternative to such a message, the suction can be prevented by, for example, the drive unit not being able to be activated due to a corresponding locking effected by the control unit.

The above object is also achieved with a vacuum cleaner which operates according to the method as described here and below and comprises means for carrying out the method. The invention is preferably implemented in software or firmware. The invention is thus on the one hand also a computer program with computer-executable program code instructions and on the other hand a storage medium with such a computer program and finally also a control unit or a vacuum cleaner with such a control unit, in whose memory as means for carrying out the method and its embodiments, such a computer program loaded or loadable. With regard to a high processing speed, an implementation of the method or individual aspects of the method in firmware, ie, for example, in the form of an ASIC, may also be considered. For ease of linguistic presentation, an implementation in firmware or a partial implementation in firmware and a partial implementation in software of the term computer program should be included.

The advantage of the invention and its embodiments is thus in particular that based on the approach proposed here, especially the previous mechanical dust bag level indicator can be omitted entirely. Their costs can be saved. In addition, fall in the previous mechanical dust bag level indicator principle leaks and leaks and associated efficiency losses away. Suction efficiency and suction power thus increase and a certain suction power can also be achieved with a drive unit with a lower power consumption. In addition, air noise is eliminated, which previously occurred due to the inherent leaks. Due to the now possible, more precise level monitoring can be a bursting of the dust bag during operation due to ignorance of the user of the vacuum cleaner on the actual degree of filling of the dust bag avoid. In addition, the power consumed in each case can be reduced when the dust bag is full or even successively automatically depending on the fill level be reduced to protect the vacuum cleaner. The user recognizes it or on a level indicator when the dust bag is filled and has the ability to early provide new dust bag ready or vorzuhalten. Finally, the user can use the entire meaningful volume of the dust bag due to the now possible accuracy of the level control without having to perform a premature and costly change of the dust bag. Overall, the level monitoring is independent of different load conditions on the floor nozzle or on the intake manifold and regardless of the selected power setting of the vacuum cleaner. The fill level monitoring also reacts reliably in the event of clogged suction pipes or floor nozzles or in the event of leaks in the dust space, for example a trapped dust bag.

An embodiment of the invention will be explained in more detail with reference to the drawing. Corresponding objects or elements are provided in all figures with the same reference numerals. The or each embodiment is not to be understood as limiting the invention. Rather, within the scope of the present disclosure, numerous modifications and variations are possible, for example, by combination or modification of the individual elements or method steps described in the general description, or each embodiment and the claims, and included in the drawings for the expert with regard to solving the problem can be removed and lead by combinable features to a new object or to new process steps or process steps.

Figur 1

einen Staubsauger an sich bekannter Art in einer Ausführungsform als Bodenstaubsauger,

Figur 2

eine Kennlinie eines Staubsaugers,

Figur 3

zwei Kennlinien eines Staubsaugers,

Figur 4

eine Steuerungseinheit eines Staubsaugers,

Figur 5, 6

Flussdiagramme zur Veranschaulichung des Verfahrens zur Füllstandsüberwachung bei einem Staubsauger,

Figur 7

eine Anzeigeeinrichtung eines Staubsaugers,

Figur 8

ein Flussdiagramm zur Veranschaulichung einer Ansteuerung der Anzeigeeinrichtung und

Figur 9

ein Schaltbild zur Veranschaulichung des Aspekts der Begrenzung der Leistungsaufnahme des Sauggebläses in Abhängigkeit vom Ergebnis der Füllstandsüberwachung.

Show it

FIG. 1

a vacuum cleaner of a known type in one embodiment as a vacuum cleaner,

FIG. 2

a characteristic of a vacuum cleaner,

FIG. 3

two characteristics of a vacuum cleaner,

FIG. 4

a control unit of a vacuum cleaner,

FIG. 5, 6

Flow charts to illustrate the method for level monitoring in a vacuum cleaner,

FIG. 7

a display device of a vacuum cleaner,

FIG. 8

a flowchart for illustrating a control of the display device and

FIG. 9

a circuit diagram for illustrating the aspect of limiting the power consumption of the suction fan in dependence on the result of the level monitoring.

FIG. 1 schematically shows a simplified vacuum cleaner 1 in one embodiment as a vacuum cleaner. However, the invention is basically suitable for any vacuum cleaner 1 which is equipped with a blower unit with a motor-driven suction fan 2. The vacuum cleaner 1 shown has a housing 3 which is divided into a fan chamber 4 and a dust collecting space 5. In the fan chamber 4, the suction fan 2 is directed with its suction side to the dust collection chamber 5 and generates there a negative pressure, which is passed through a connected suction hose 6 and a suction pipe 7 to the suction mouth of a floor nozzle 8. Thus, air laden with dirt 9 - represented by the arrows 10 - is absorbed on the processed substrate (suction air stream) and cleaned by means of a dust separator. In the exemplary embodiment, this is a dust bag 11 functioning as a dust collecting container with a downstream engine filter 12. The cleaned air is returned to the environment via an exhaust air filter unit 13. The fan motor 14 of the suction fan 2 is controlled in a conventional manner via an electronic control unit 15 for controlling power semiconductors such as an inverter 16. The fan motor 14 of the suction fan 2 is the drive unit of the vacuum cleaner 1. It is in operation of the vacuum cleaner 1 in fed in a known manner with electrical power and generates a negative pressure and finally a volume flow as the basis for the suction air flow. For operation and for user information, an operating and display device 17 is provided.

FIG. 2 schematically shows a simplified characteristic 20 of a vacuum cleaner 1 ( FIG. 1 ). As an example, characteristic curve 20 shows a characteristic of the converted air power (symbol P2) when the dust bag 11 is full (FIG. FIG. 1 ) or dust collector: P2_voll. In principle, the approach according to the invention is also suitable for the use of other characteristics. It is only important that the respective characteristic is a volumetric flow-dependent characteristic, so that a measure of the volumetric flow is always included in the level monitoring or filling level determination. In the FIG. 2 Characteristic curve 20 shown is a volume-flow-dependent characteristic because the converted air power results from the product of the negative pressure (formula symbol h) and the resulting volume flow (formula symbol q): P2 = h * q. In this respect, for the characteristic 20 in FIG. 2 plotted on the abscissa 23, the volume flow q in cubic meters per second and plotted on the ordinate 22, the resulting air flow P2.

In operation of the vacuum cleaner 1, data is acquired for a measure of an actual vacuum and a measure of an actual volume flow. As a measure of the actual negative pressure h, a pressure in the suction hose 6 or at the entrance of the dust bag 11 or dust collecting container can be measured with a pressure sensor as a differential pressure sensor against ambient pressure, in particular an analogous such pressure sensor in the region of the inlet opening of the vacuum cleaner. For the determination of the For example, it is possible to provide a further, in particular analog differential pressure sensor in the immediate vicinity of the suction fan 2, for example in the region of a motor protection grid usually provided there. The measured differential pressure between static / dynamic pressure decrease (Pitot probe) correlates very well with the volume flow q in the measuring range under consideration. Alternatively, for example, a hot wire, a pressure connection to the suction fan 2 or the derivation of the volume flow q from the engine characteristics would be thinkable and feasible.

In a memory of the control unit 15 (FIG. FIG. 1 ) are data for at least one characteristic 20 of the in FIG. 2 filed type. This may be data for individual interpolation points of the or each respective characteristic curve 20, ie value pairs from which the characteristic curve (s) can be interpolated, or else an algorithmic or mathematical description of the characteristic curve (s) 20.

On the basis of the recorded data for the negative pressure h and the volume flow q, a current operating point 24 is determined (q_akt / P2_akt = q_akt / (q_akt * h_akt)). This one is in the illustration in FIG. 2 entered. The determined operating point 24 is related to the at least one characteristic curve 20 by precipitating a solder 25 onto the characteristic curve 20. Thus, an operating point 26 (q_akt / P2_voll = q_akt / (q_akt * h_voll) belonging to the actual volume flow (q_akt) is determined on the characteristic curve 20.

On the basis of the instantaneous operating point 24 (or directly on the actual flow q_akt) and the operating point 26 on the characteristic curve 20, two air power values P _{2 are obtained} , wherein the P ₂ value associated with the operating point 24 is referred to as P ₂ _akt and that to the operating point 26 on the Characteristic 20 associated P ₂ value as P ₂ _voll is called because the current operating point 24 is determined by the actual or current air performance and the characteristic 20 was taken in the example chosen for a full dust bag 11 / full dust collector. Based on the two P ₂ values P ₂ _akt and P ₂ _ full (and / or the respectively associated negative pressure values h_akt and h_voll), a quotient can be formed as follows: $$\mathrm{x}\mathrm{=}{\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="imgf0001.png"\; state="\{\{state\}\}">P</figure-callout>}}_{\mathrm{2}\mathrm{\_}}\mathrm{act}\mathrm{/}{\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="imgf0001.png"\; state="\{\{state\}\}">P</figure-callout>}}_{\mathrm{2}\mathrm{\_}}\mathrm{full}\mathrm{,}$$

wobei die Koeffizienten a und b für jedes Staubsaugermodell empirisch ermittelt werden und in der Steuerungseinheit 15 abgelegt sind.The quotient x results in the degree of filling or a measure of the degree of filling by insertion into $$\mathrm{F}\mathrm{=}\mathrm{a}{\mathrm{x}}^{\mathrm{\wedge }}\mathrm{2}\mathrm{+}\mathrm{b}\mathrm{*}\mathrm{x}\mathrm{.}$$

wherein the coefficients a and b are determined empirically for each vacuum cleaner model and stored in the control unit 15.

In an alternative embodiment of the approach according to the invention, the use of multiple vacuum cleaner characteristics in the sense of the definition introduced above, ie characteristics in the form of a sequence of pairs of values or characteristics in the form of a mathematical description, can be provided. Then at least two characteristics are used and FIG. 3 shows insofar as an example in this sense, first and second characteristic 20, 21 in each case a characteristic of the converted air power (symbol P2) with a full or empty bag / dust collector.

Again, as described above, a measure of an actual negative pressure h and a measure of an actual volume flow q are taken in each case. The resulting operating point 24 is as in FIG. 2 also in FIG. 3 located. On the basis of the operating point 24, at least one characteristic curve 20, 21 which best suits this is selected. In the illustrated situation, this is the second characteristic 21, for example, because the distance of the operating point 24 to the second characteristic 21 is less than to the first characteristic 20.

A current level of the vacuum cleaner 1, namely the degree of filling of the dust bag 11 or dust collection, then results from the selected characteristic (s) 20, 21 and the level situation for which this was originally recorded (s). After, according to the condition described at the outset, the second characteristic curve 21 for a filled dust bag 11 or dust collecting container had been recorded, a filled dust bag 11 results as instantaneous fill level in this simplified consideration. Indeed, a plurality of characteristic curves 20, 21 can be used, eg a plurality of characteristics that represent a full, then increasingly less filled dust bag 11 / dust collection in eg 1%, 2% or 5% intervals. If a maximum spatial proximity to a characteristic curve 20, 21 of such a family of characteristics is determined for an operating point 24, a very accurate statement about the filling level and thus a very accurate level monitoring is possible. In addition, interpolation of the filling level is also possible with an operating point 24 lying between two characteristic curves 20, 21. Even at the in FIG. 2 shown situation with only two characteristics 20, 21 can be made on this basis, a fairly accurate statement about the level by the distances 25, 27 - for example, as in FIG. 2 drawn in - used and put in relation. The illustrated distance 27 is approximately half as large as the illustrated distance 25. With regard to the level of the dust bag, this can be interpreted as "approximately 2/3 full".

The use of a plurality of characteristic curves 20, 21 - ie the use of at least two characteristic curves 20, 21 -, wherein in FIG. 3 for the sake of clarity only two characteristics 20, 21 are shown, has the advantage that only on the basis of the determination of one or more to the respective operating point the best matching characteristics 20, 21, a measure of the respective degree of filling can be determined. A subsequent formulaic evaluation as with the above-copied equation [1] is not necessary. However, this variant requires more storage space in the control unit 15 in order to store the at least two characteristic curves 20, 21.

wobei P_leer(q) und P_voll(q) jeweils Werte der entsprechenden volumenstromabhängigen Kennlinien an der durch den aktuellen Volumenstrom q spezifizierten Stelle bezeichnen. Dann ergibt sich auch bei dieser Variante der momentaner Füllstand des Staubbeutels oder Staubsammelbehälters des Staubsaugers 1 anhand der ausgewählten Kennlinien 20, 21, nämlich der Kennlinien für den leeren und vollen Beutel/Behälter, und der Füllstandssituation, für welche diese ursprünglich aufgenommen wurde.A variant in the use of multiple characteristics, namely at least one characteristic (P _empty ) for an empty dust bag 11 / dust collector and a characteristic (P _full ) for a full dust bag 11 / dust collector, as basically with the curves 20, 21 in FIG. 3 is shown that continuously or at predetermined or predeterminable, in particular equidistant times, the instantaneous air power P2 _akluell , which results as a product of the respective vacuum _{measured value} h and the respective volumetric flow value q, is calculated and in relation to the characteristics for the empty and the full bag is set so that there is _currently an operating point with the current air flow P2, which is related to the two characteristics as follows $$Fü\mathit{llgrad}=\frac{{P2}_{\mathit{current}}-P_{\mathit{empty}}\left(q\right)}{P_{\mathit{full}}\left(q\right)-P_{\mathit{empty}}\left(q\right)}\cdot 100\%.$$

where P _empty (q) and P _full (q) respectively denote values of the corresponding volume flow dependent characteristics at the location specified by the current volume flow q. Then results in this variant, the current level of the dust bag or dust collector of the vacuum cleaner 1 based on the selected characteristics 20, 21, namely the characteristics of the empty and full bag / container, and the level situation for which it was originally recorded.

FIG. 4 schematically shows in simplified form the control unit 15 (FIG. FIG. 1 ) with further details. Thereafter, the control unit 15 comprises a memory 30 and a processing unit 31 in the form of or in the manner of a microprocessor, ASIC or the like. In the memory 30 are data 32 for vacuum cleaner characteristics, namely volume flow-dependent characteristic curves 20, 21 (FIG. FIG. 2 . FIG. 3 ), ie, for example, pairs of associated h and q values or algorithmic or mathematical descriptions of such characteristics 20, 21. In addition, a control program 33 is stored in the memory 30, which is executed during operation of the vacuum cleaner 1 by the processing unit 31.

Under control of the control program 33, as described above and as shown by the flowchart 34 in FIG FIG. 4 again graphically illustrated - first data for a measure of an actual negative pressure h and a measure of an actual Volume flow q recorded (first function block 40). Based on the thus determined operating point 24 ( FIG. 2 ), the current flow value (q_akt) and the flow value (q_voll) belonging to the respective characteristic curve 20 can be determined (second function block 41). The thus determined quotient (x) can be inserted into the above-copied-in equation [1] and from this an instantaneous degree of filling or at least one measure of the instantaneous degree of filling can be determined (third function block 42).

In the alternative embodiment as in FIG. 3 the sequence of the control program 33 is represented by the in FIG. 6 shown flowchart 34 'shown. First, as in FIG. 5 a measure of an actual negative pressure h and a measure of an actual volume flow q are recorded (first functional block 40 '). The resulting operating point 24 ( FIG. 3 ) is then related to the one or more characteristic curves 20, 21, and at least one characteristic curve 20, 21 that best fits the instantaneous operating point 24 is selected from the characteristic curve (s) 20, 21 (second function block 41 '). Finally, the instantaneous filling level of the vacuum cleaner 1 is determined on the basis of the selected characteristic curve (s) 20, 21 and the filling level situation for which it was originally recorded (third functional block 42 ').

FIG. 7 schematically shows a simplified display 17 for displaying the determined level. Shown is a situation in which the determined level is displayed with a segmented optical bar graph. The display device 17 is assigned as a control and display device, for example, a button 50, with which the display can be switched between a level indicator and a state of charge indicator of a battery for driving the vacuum cleaner 1 or the like.

FIG. 8 shows the third functional block 42, 42 '( FIG. 5 respectively. FIG. 6 ) with further details. Thereafter, it is checked in a fourth function block 60 whether the determined fill level is above a predetermined or predefinable threshold value. When the threshold value is reached or exceeded, the display device 17 automatically switches over to display the fill level (fifth function block 61). Then it is checked in a sixth function block 62, whether the determined level is above a predetermined or predeterminable limit value and upon reaching or exceeding the limit, a message, for example, a warning or information to the user of the vacuum cleaner 1, generated (seventh function block 63) , Finally, it is checked in an eighth function block 64 whether the determined fill level is above a predefined or predefinable alarm level and, on reaching or exceeding the alarm level, the electrical power consumed or absorbed by the drive unit is reduced (ninth function block 65).

Finally, this last aspect FIG. 9 is still using a simplified circuit diagram, in which it is shown that the control unit 15 controls the inverter 16 as an actuator for limiting the power consumption of the blower motor 14 of the suction fan 2 when the alarm level is reached. For the control unit 15, the input values considered by the latter are represented by three lateral arrows, namely an external power specification for the blower motor 14, a signal from the differential pressure sensor in the region of the inlet opening of the vacuum cleaner 1 for detecting the negative pressure h and a signal from the differential pressure sensor in the region of the suction blower 2 for detecting the volume flow q.

Overall, in the proposed approach, the converted air power (symbol P2) can also be considered as a function of absorbed electrical power (symbol P1), because the P2 characteristics are not only the degree of filling of the bag, but also independent of the degree of filling of the engine power P1 used dependent. This can be provided as an extension of the approaches presented here that each not only a characteristic or a few of curves or a family of characteristics is included, but that such characteristics for each adjustable power P1 or at least individually adjustable power P1 recorded and in the memory 30 of the control unit 15 are stored retrievable. If respective electrical power P1 is known, the or each characteristic recorded for this power can be retrieved from the memory and each of the previously described evaluations can be made on the basis of one or more characteristic (s) matching the respectively set power P1. For the detection of the electrical power comes a variety of possibilities: The recorded electrical power P1 should preferably be measured directly. Alternatively, it can also be derived from the phase angle and the motor type and / or the volume flow q or estimated with sufficient accuracy. In the case of guided motors, information regarding the electrical power consumed can be obtained directly from the information of the converter. Furthermore, an estimation of the recorded engine power due to the combination of the steepness of an h / q characteristic and the location of h_akt / q_akt is sufficiently possible.

Thus, the central aspect of the description presented here can be briefly represented as follows: Specified is a method for level monitoring in a vacuum cleaner 1, wherein data for a vacuum generated by the drive unit of the vacuum cleaner 1 and volume flow are recorded during operation, wherein in a memory 30 data 32 for volume flow-dependent characteristics 20, 21 are stored, wherein at least on the basis of the actual volume flow, an operating point 26 on a characteristic curve and a 26 associated with the operating point on the characteristic negative pressure and with the actual negative pressure and the value for the negative pressure based on the characteristic 20th , 21 one Current level of the vacuum cleaner 1 is determined and / or wherein based on the actual volume flow and negative pressure, a current operating point 24 is determined and to the one or more curves 20, 21 so related that from the one or more characteristics 20, 21 at least one of this best matching is selected and the current level of the vacuum cleaner 1 based on the selected characteristic (s) 20, 21 and a level situation, for which this was originally recorded results.

LIST OF REFERENCE NUMBERS

1

vacuum cleaner

2

aspirator

3

casing

4

blower room

5

Dust collection chamber

6

suction

7

suction tube

8th

floor nozzle

9

dirt

10

Arrow (to show dirty air)

11

anther

12

motor filter

13

Exhaust air filter unit

14

blower motor

15

control unit

16

inverter

17

Operating and display device

20

curve

21

curve

22

ordinate

23

abscissa

24

(current) operating point

25

distance

26

Operating point (on the characteristic curve)

27

distance

30

Storage

31

processing unit

32

dates

33

control program

34, 34 '

flow chart

40 - 42

(first, second or third) function block

50

button

60 - 65

(fourth, fifth, sixth, seventh, eighth, and ninth) function blocks

Claims (15)

Method for level monitoring in a vacuum cleaner (1),
wherein the vacuum cleaner (1) comprises a power-driven electric power generating unit that generates a negative pressure and a volumetric flow, wherein data is acquired during operation for a measure of an actual negative pressure and a measure of an actual volume flow,
characterized,
in that data (32) for at least one volume-flow-dependent characteristic curve (20, 21) are stored in a memory (30),
that an operating point (26) on the at least one characteristic curve (20, 21) is determined on the basis of the actual volume flow, and
in that, on the basis of the actual negative pressure and the negative pressure associated with the operating point (26) on the characteristic curve, an instantaneous filling level of the vacuum cleaner (1) is determined. Method for level monitoring in a vacuum cleaner (1),
wherein the vacuum cleaner (1) comprises a power-driven electric power generating unit that generates a negative pressure and a volumetric flow, wherein data is acquired during operation for a measure of an actual negative pressure and a measure of an actual volume flow,
characterized,
in that data (32) for at least one volume-flow-dependent characteristic curve (20, 21) are stored in a memory (30) for specific filling level situations,
that a current operating point (24) is determined on the basis of the actual negative pressure and the actual volume flow,
in that the determined instantaneous operating point (24) is related to the characteristic curve (s) (20, 21) and from the characteristic curve (s) (20, 21) at least one characteristic curve (20, 21) which best suits the instantaneous operating point (24). is selected and
that an instantaneous filling level of the vacuum cleaner (1) based on the selected characteristic curve (20, 21) and the fill level situation for which it was originally recorded, is obtained. Method according to Claim 2, wherein the instantaneous operating point (24) is related to the characteristic curves (20, 21) and from the characteristic curves (20, 21) two or more characteristic curves (20, 21) which are best suited to the instantaneous operating point (24) ) and wherein a current level of the vacuum cleaner (1) based on the selected characteristic curves (20, 21) and an interpolation of the level situations for which they were originally recorded results. The method of claim 1, 2 or 3, wherein for different adjustable electrical power (P1) each volume flow-dependent characteristics (20, 21) are recorded and stored in the memory (30), wherein the set electrical power (P1) in the operation of the vacuum cleaner ( 1) is detected and selected from the detected set electrical power (P1) or each for this electrical power (P1) recorded, volume flow-dependent characteristics (20, 21). The method of claim 1, 2, 3 or 4, wherein a current level is represented by means of an optical display device (17). A method according to claim 5, wherein the display device (17) is used as an alternative to the level indicator and to display a further operating parameter of the vacuum cleaner (1), in particular a residual capacity of a battery for powering the vacuum cleaner (1). The method of claim 6, wherein at a level above a predetermined or predetermined threshold, the display device (17) is automatically switched to display the level. A method according to claim 6 or 7, wherein at a level above a predetermined or predeterminable limit, a message to the user of the vacuum cleaner (1). Method according to one of claims 1 to 8, wherein at a level above a predetermined or predetermined alarm level, the electrical power absorbed by the drive unit is reduced. The method of claim 9, wherein the reduction of the electrical power to a predetermined or predeterminable level. Method according to one of claims 1 to 10, wherein in a not or not completely closed dust chamber closure a message to the user of the vacuum cleaner (1). Method according to one of claims 1 to 11, wherein in a non-inserted dust bag, a message to the user of the vacuum cleaner (1). Vacuum cleaner (1) with means for carrying out the method according to one of the preceding claims. A computer program comprising computer executable program code instructions for implementing the method of any one of claims 1 to 12 when the computer program is executed by a microprocessor (31). Vacuum cleaner (1) according to Claim 13, having a control unit (15) comprising a memory (30) and a microprocessor (31) as means for carrying out the method according to one of Claims 1 to 12 and one loaded into the memory (30) Microprocessor (31) executable control program (33) as a computer program according to claim 14.

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