Method for determining the fill level in a fresh water zone of a receiving tank of a floor cleaning machine

Abstract

A method for determining the fill quantity of a fresh water section (17) in a receiving tank (13) of a floor cleaning machine (1) is presented and described, wherein the floor cleaning machine (1) comprises the fresh water section (17), a wastewater section (19), a chassis (3) for moving the floor cleaning machine (1) over a floor surface (11) to be cleaned, a cleaning device (7) for cleaning the floor surface (11), a receiving device (25) for receiving wastewater from the floor surface (11), and a conveying device (33) configured to convey wastewater from the receiving device (25) to the wastewater section (19) in an activated state, wherein the fresh water section (17) and the wastewater section (19) are formed in a receiving tank (13) and are separated from each other by a flexible partition wall configured as follows:that the fresh water area (17) and the wastewater area (19) cannot extend, partially or completely, over the cross-section of the receiving tank (13), and wherein the method comprises the following steps: detecting the volume flow from the fresh water area (17) at at least one time point between a first time point and a second time point, wherein the first time point is before the second time point, and determining the current fill quantity in the fresh water area (17) from a previously determined fill quantity and the detected volume flow.

Description

[0001] The present invention relates to a method for determining the filling quantity of a fresh water area in a receiving tank of a floor cleaning machine.

[0002] The floor cleaning machine comprises the fresh water area, a dirty water area, a chassis for moving the floor cleaning machine over a floor surface to be cleaned, a cleaning device for cleaning engagement with the floor surface to be cleaned, wherein the cleaning device is connected to the fresh water area and is designed to apply fresh water to the floor surface to be cleaned, a receiving device for receiving dirty water from the floor surface to be cleaned, and a conveying device which is designed, in an activated state, to convey dirty water from the receiving device to the dirty water area, wherein the fresh water area and the dirty water area are formed in a receiving tank and are separated from one another by a flexible partition wall which is designed such that the fresh water area and the dirty water area do not,may extend partially or completely over the cross-section of the receiving tank.

[0003] Such floor cleaning machines with a flexible partition wall are known from the prior art. Before such floor cleaning machines were used, the dirty water and fresh water compartments were each designed as tanks with rigid walls, which, however, had the following disadvantage.

[0004] When such a floor cleaning machine is in operation, the fresh water area is completely full at the beginning of operation, while the dirty water area is empty. As operation continues, fresh water is applied from the fresh water area to the floor area to be cleaned. This fresh water, after absorbing dirt from the floor surface, is then pumped into the dirty water area by the conveyor system.

[0005] This means that the fill level in the fresh water compartment decreases during operation while the fill level in the dirty water compartment increases. The sum of both should not exceed the initial fresh water volume, provided that no additional water is applied to the floor surface to be cleaned. However, if solid-walled tanks are used for fresh water and dirty water, an unnecessary amount of volume is retained, which increases the size of the floor cleaning machine and thus limits its maneuverability.

[0006] Therefore, it is known from DE 10 2019 110 634 A1 to provide a receiving tank in the floor cleaning machine, in which a flexible partition wall is provided that divides the volume of the receiving tank into a dirty water area and a fresh water area. The partition wall is designed such that the cross-sectional area of ​​the dirty water area and the fresh water area can extend completely, partially, or completely over the cross-sectional area of ​​the receiving tank.

[0007] The partition wall therefore allows the volume of the receiving tank to be occupied either entirely, partially, or not at all by one of the fresh water area and the dirty water area. Furthermore, the volume of the receiving tank can be divided as desired between the dirty water area and the fresh water area. However, a level is always established in the dirty water area and the fresh water area such that liquid is distributed completely across the cross-section of the receiving tank up to the level. Therefore, there are no areas in the receiving tank below the level that are not filled with liquid from the dirty water area or the fresh water area. Another floor cleaning machine with the aforementioned features is known from EP 0 173 392 A2.Also known from DE 10 2018 221 058 A1 are floor cleaning machines with recovery of cleaning fluid with a container for storing the cleaning fluid and a filter element and a dirt collection device for collecting contaminated cleaning fluid and transferring it into the container.

[0008] With such a floor cleaning machine, the following technical problem arises. Since the volume of the fresh water compartment is not fixed, the fill level of the fresh water compartment cannot be simply determined from the level within it. In particular, it is unknown to what extent the volume of the receiving tank is also occupied by dirty water. Even determining the level in the dirty water compartment and the fresh water compartment does not allow the respective fill levels to be determined, since the position of the partition wall cannot be determined.

[0009] Therefore, the object of the present invention is to provide a method that allows a reliable determination of the filling quantity of the fresh water tank.

[0010] According to the invention, this object is achieved by a method for determining the filling quantity of the fresh water area of ​​a floor cleaning machine, wherein the floor cleaning machine comprises the fresh water area, a dirty water area, a chassis for moving the floor cleaning machine over a floor surface to be cleaned, a cleaning device for cleaning engagement with the floor surface to be cleaned, wherein the cleaning device is connected to the fresh water area and is designed to apply fresh water to the floor surface to be cleaned, a receiving device for receiving dirty water from the floor surface to be cleaned, wherein the receiving device is connected to the dirty water area, and a conveying device which is designed to convey dirty water from the receiving device to the dirty water area in an activated state.wherein the fresh water area and the dirty water area are formed in a receiving tank and are separated from each other by a flexible partition wall which is designed such that the fresh water area and the dirty water area cannot extend, partially or completely over the cross section of the receiving tank, and wherein the method comprises the following steps: , Detecting the volume flow out of the fresh water area at at least one time between a first time and a second time, wherein the first time is before the second time, and determining the current filling quantity in the fresh water area from a previously determined filling quantity and the detected volume flow.

[0011] The method according to the invention thus uses a floor cleaning machine in which the dirty water tank is divided into a fresh water zone and a dirty water zone by a flexible partition wall, as already described in connection with the prior art. The partition wall and the receiving tank are designed in such a way that pressure equalization always occurs between the fresh water zone and the dirty water zone. Here, too, the flexible partition wall allows the volume of the receiving tank to be occupied either completely, partially, or not at all by one of the fresh water zone and the dirty water zone, and the volume of the receiving tank can be divided as desired between the dirty water zone and the fresh water zone.In the wastewater area and the freshwater area, a level is always set in such a way that liquid is distributed completely over the cross-section of the receiving tank up to the height of the level, and below the level there are no areas in the receiving tank that are not filled with liquid from the wastewater area or the freshwater area.

[0012] Furthermore, in the method according to the invention, the current fill level is determined based on a previously determined fill level in the fresh water area by continuously or possibly only once recording the volume flow flowing out of the fresh water area and, if applicable, to the purification device between a first point in time and a second point in time. From this volume flow, the discharged amount of fresh water is determined and subtracted from the fill level in the fresh water area last determined, i.e., at or before the first point in time.

[0013] In this context, it should be noted that the floor cleaning machine for carrying out the method may not only comprise the cleaning device which is designed for cleaning engagement with the floor surface to be cleaned, but it is also conceivable that further additional cleaning devices are provided, such as a hand brush or a high-pressure cleaner, which are also supplied with fresh water from the fresh water area.

[0014] The method can preferably be configured such that, during a run prior to commencing the actual cleaning operation and prior to the initial activation of the cleaning device after filling the fresh water area and the associated discharge of fresh water, the initial fill level in the fresh water area is determined from the level in the receiving tank. This can be done particularly when the dirty water area is empty. In the further course of the method, the last determined fill level is then always used iteratively, and the discharged fresh water volume is determined based on the volume flow determined between two points in time.

[0015] The floor cleaning machine used according to the invention has a chassis that allows the floor cleaning machine to be moved across the floor area to be cleaned. In this context, the term "chassis" is to be understood broadly, encompassing any type of wheels or sliding elements, which may or may not be driven, and serve to enable mobility. Furthermore, the term "floor cleaning machine" includes self-propelled machines as well as those that are guided by a user while walking in front of or behind the machine.

[0016] In a preferred embodiment of the method, the level in the receiving tank is detected, wherein the fill level in the dirty water area is determined from the current fill level in the fresh water area and the level in the receiving tank. The level in the receiving tank can be detected by detecting the level in the fresh water and / or dirty water area. Since the level is the same in both areas, this is also the level in the receiving tank. In this embodiment, in addition to the fill level in the fresh water area, the fill level in the dirty water area can also be determined. This can be done in particular by determining the total fill level in the receiving tank based on the detected level in the tank and subtracting the fill level in the fresh water area from this.

[0017] In a further preferred embodiment of the method according to the invention, it is detected whether the conveying device is in the activated state and / or whether fresh water is being conveyed out of the fresh water area and / or whether the floor cleaning machine is stationary, wherein the level in the receiving tank is detected. If the conveying device is not in the activated state and / or no fresh water is being conveyed out of the fresh water area and / or the floor cleaning machine is stationary, it is determined whether the level in the receiving tank is rising, wherein, if the level in the receiving tank is rising, the current fill level in the fresh water area is determined from the increase in the level in the receiving tank and the last determined fill level in the fresh water area.The determination of whether the level in the receiving tank is rising does not have to be made exclusively when the conveying device is not in the activated state and / or no fresh water is being conveyed out of the fresh water area and / or the floor cleaning machine is at a standstill.

[0018] This preferred embodiment of the method addresses the problem of a user of the floor cleaning machine interrupting operation and refilling the fresh water compartment. If only the outflowing volume flow is taken into account and a previously determined fill level is assumed, this would not be accurately captured when determining the actual fill level in the fresh water compartment.

[0019] For this purpose, this embodiment of the method now provides that it is first checked whether the conveying device is activated, i.e. that dirty water is being drawn away from the floor area to be cleaned, and / or whether no fresh water is being drawn out of the fresh water area and possibly onto the floor area to be cleaned, i.e. for example whether a minimum volume flow from the fresh water area to the floor area to be cleaned has been undershot, and / or whether the floor cleaning machine is at a standstill. Each of these three conditions, alone or all of them together, if met, indicates that the machine is not currently in actual cleaning mode, so that there is a possibility that the user is adding fresh water to the fresh water area. For this purpose, it may be sufficient to check whether the conveying device is activated and no fresh water is flowing out of the fresh water area.

[0020] Thus, in this embodiment of the method, if at least one of these conditions is met, the level in the receiving tank is monitored, and if it rises, it is assumed that this is due to the addition of fresh water. The current fill level of the fresh water area is then determined by adding the volume resulting from the increase in the level in the receiving tank to the last determined fill level of the fresh water tank.

[0021] In a further preferred manner, in this embodiment, the current filling quantity in the waste water area is determined as the filling quantity last determined there.

[0022] In a further preferred embodiment of this exemplary embodiment, if the level in the receiving tank is not rising, the current fill level in the dirty water area is determined from the level in the receiving tank and the last determined fill level in the fresh water area. In this way, the fill level in the dirty water area can then also be easily determined.

[0023] Furthermore, in a further preferred embodiment of this exemplary embodiment of the method, it can again be detected whether the conveying device is in the activated state, wherein it is further detected whether fresh water is being conveyed out of the fresh water area and / or whether the floor cleaning machine is stationary, wherein the level in the receiving tank is detected, and wherein, if the conveying device is not in the activated state and if fresh water is being conveyed out of the fresh water area and / or the floor cleaning machine is not stationary, the current fill level in the dirty water area is determined from the level in the receiving tank and the last determined fill level in the fresh water area. Alternatively, it is also possible for the current fill level in the dirty water area to be assumed to be previously determined, since due to the deactivated conveying device, no dirty water can reach the dirty water area.

[0024] This embodiment takes into account the case where the conveying device is in the deactivated state, but other conditions that must be met for the fresh water area to be filled are not met. In this embodiment, it is assumed that the fill level in the fresh water area remains unchanged.

[0025] Furthermore, it is preferred if the level in the receiving tank is detected by detecting the level in the fresh water area or by detecting the level in the dirty water area. Alternatively, it is also preferred that the level in the receiving tank is detected by detecting the level in the fresh water area and detecting the level in the dirty water area, wherein the level in the receiving tank is determined as the maximum of the level in the fresh water area and the level in the dirty water area. With this second alternative, greater reliability is achieved in determining the level in the receiving tank, and additional information is obtained.

[0026] In particular, it is possible for the levels to be detected, particularly in these alternatives, by detecting the pressure in the bottom area of ​​the fresh water area and the dirty water area. Additionally, the pressure above the level in the dirty water area can be detected, especially if the conveying device is designed as a suction turbine. The level in the dirty water area and / or the fresh water area is then determined based on the differential pressure between the pressure in the bottom area and the pressure above the level. In this way, a reliable determination of the level is possible. It can also be detected whether one of the fresh water area and the dirty water area is empty.

[0027] In a further preferred embodiment, the volume flow out of the fresh water area is detected at at least one point in time between the first point in time and the second point in time, and the current fill level in the fresh water area is determined when the level in the fresh water area is greater than a first minimum level and when the level in the waste water area is greater than a second minimum level. In this way, the comparatively complex determination of the fill level of the fresh water area is only performed if this is not already possible based on the detection of the level in the receiving tank.

[0028] In a further preferred manner, if the level in the fresh water area is less than or equal to a first minimum level and if the level in the dirty water area is greater than a second minimum level, the fill level in the fresh water area can be determined as minimum, and the fill level in the dirty water area can be determined from the level in the receiving tank and the cross-section of the receiving tank. This exemplary embodiment also avoids a complex determination of the fill level in the dirty water area and in the fresh water area, which would involve detecting the volume flow from the fresh water area.

[0029] In this context, it should be noted that the first and / or second minimum level according to the present invention can also be the level that results when the wastewater area or the freshwater area is empty. Then, of course, this minimum level cannot be undercut during detection, and the detected level cannot be lower than the minimum level with this option. However, it is also possible for the first and / or second minimum level to be selected such that they are higher than the levels that result when the respective areas are empty.

[0030] In particular, the fill volume in the wastewater area can be determined from the level in the receiving tank by "integrating" the cross-section along the level height. This applies very generally within the scope of the present invention. If the total fill volume is to be determined from the level in the receiving tank, this can always be done by integrating it over the cross-sectional area along the level height. This takes into account a non-uniform cross-section of the receiving tank.

[0031] In a further preferred embodiment, if the level in the fresh water area is less than or equal to a first minimum level and if the level in the waste water area is less than or equal to a second minimum level, the fill level in the fresh water area is determined to be minimal and the fill level in the waste water area is determined to be minimal. Here, too, it can be concluded directly from the detection of the levels in the fresh water area and in the waste water area that these levels are minimal or that the two containers are empty. Here, too, a determination of the fill levels based on the volume flow detection is no longer necessary.

[0032] Finally, in a further preferred embodiment, if the level in the fresh water area is greater than a first minimum level and if the level in the dirty water area is less than or equal to a second minimum level, the filling quantity in the dirty water area can be determined as minimum and the filling quantity in the fresh water area can be determined from the level in the receiving tank and the cross section of the receiving tank.

[0033] Finally, the present invention provides a floor cleaning machine for carrying out the method in one of the forms described above.

[0034] In the following, the present invention is explained with reference to a drawing showing only a preferred embodiment, in which Fig. 1 shows a floor cleaning machine for carrying out the method according to the invention in a longitudinal cross-section and Fig. 2 shows a flow diagram of an embodiment of a method according to the invention.

[0035] As from Figure 1 As can be seen, an embodiment of a floor cleaning machine 1 for carrying out the embodiment of a method according to the invention, which is shown in Figure 2 As shown, the floor cleaning machine 1 has a chassis 3, which in the present embodiment has three wheels 5, the front wheels being steerable, and the floor cleaning machine 1 being designed as a ride-on machine so that a user can steer the machine. However, the present invention is not limited to ride-on machines, but rather also applies quite generally to floor cleaning machines, which can also be designed as machines in which a user walks behind or in front of the machine.

[0036] Furthermore, the exemplary embodiment of a floor cleaning machine 1 comprises a cleaning device 7, which, in the example shown here, comprises driven brush elements 9, wherein the brush elements 9 can engage with a floor surface 11 to be cleaned, over which the floor cleaning machine 1 can be moved by means of the chassis 3. It should be noted here that the floor cleaning machine 1 can not only comprise the cleaning device 7, but it is conceivable that additional additional cleaning devices are provided, such as a hand brush or a high-pressure cleaner, which are also supplied with fresh water.

[0037] The floor cleaning machine 1 further comprises a receiving tank 13 provided with a flexible partition 15 that divides the internal volume of the receiving tank 13 into a fresh water area 17 and a dirty water area 19. The partition 15 is designed such that the fresh water area 17 and the dirty water area 19 have a variable volume, whereby the sum of the volumes always corresponds to the volume of the receiving tank 13 at this level, regardless of the level in the fresh water area 17 and in the dirty water area 19. The flexible partition 15 is designed to enable pressure equalization between the fresh water area 17 and the dirty water area 19.The partition wall 15 is thus designed to be flexible such that, regardless of the fill volumes in the fresh water area 17 and the waste water area 19, a situation arises in the receiving tank 13 in which the liquid level extends across the entire cross-sectional area of ​​the receiving tank 13 and there are no areas below the level that are not filled with liquid. In particular, the fresh water area 17 and the waste water area 19 may not extend at all, entirely, or partially across the cross-section of the receiving tank 13.

[0038] What next Figure 1As can be seen, the fresh water area 17 is connected to the cleaning device 7 via a line 21, so that fresh water from the fresh water area 17 can be applied to the floor surface 11 to be cleaned via the cleaning device 7. It can also be seen that a volume flow measuring device 23 is provided in the line 21, with which the volume flow through the line 21 and thus the volume flow out of the fresh water tank 17 and, in this exemplary embodiment, to the cleaning device 7 can be recorded. In the exemplary embodiment described here, which, in addition to the cleaning device 7, which is supplied with fresh water from the fresh water area 17, has no further additional cleaning devices that are also supplied from the fresh water area 17, the volume flow to the cleaning device 7 is recorded.However, if further additional cleaning devices are present, the volume flow measuring device must be arranged in such a way that it records the entire volume flow flowing out of the fresh water area 17 and thus flowing to the cleaning device 7 and the additional cleaning devices.

[0039] In addition, the floor cleaning machine 1 has a receiving device 25, which in the embodiment shown here is designed as a so-called suction foot 27, which has a volume 29 that is open to the floor surface 11 to be cleaned and otherwise closed, and extends across the width of the floor cleaning machine 1. The volume 29 is connected via a line 31 to the interior of the receiving tank 13 and beyond to the dirty water area 19. The interior of the receiving tank 13 is subjected to a negative pressure relative to the environment by a so-called suction turbine 33, so that the suction turbine 33 serves as a conveying device with which dirty water located on the floor surface 11 to be cleaned can be conveyed into the dirty water area 19.

[0040] Finally, sensors 35, 37 are provided in the dirty water area 17 and the fresh water area 19, with which the pressure in the bottom area of ​​the fresh water area 17 and in the bottom area of ​​the dirty water area 19 can be measured. Additionally, a further sensor (not shown here) can also be provided, which measures the pressure above the level in the receiving tank 13 in order to take into account the fact that the suction turbine 33 generates a negative pressure there. The level in the fresh water and dirty water areas 17, 19 is then determined from the pressure difference between the pressures measured by the two sensors 25, 37 and the further sensor. In this way, the level in the fresh water area 17 and in the dirty water area 19 can be measured overall based on the pressure measured by the sensors 35, 37. However, other measuring methods for measuring these levels are also conceivable.

[0041] In the following, the embodiment of a method according to the invention for determining the filling quantity in the fresh water area 17 of the floor cleaning machine 1, which is shown in Figure 1 shown, using the flow chart in Figure 2 described.

[0042] In the embodiment of a method according to the invention, the flow chart of which is shown in Figure 2As shown, after the start in step 41, the level in the fresh water area 17 is first recorded using the measuring sensor 35. At the same time or subsequently, in step 42, the level in the dirty water area 19 is recorded using the measuring sensor 37. In order to take into account that in the present exemplary embodiment the suction turbine 33 generates a negative pressure above the liquid level in the fresh water area 17 and in the dirty water area 19, which reduces the gravitational pressure of the respective liquid acting on the measuring sensors 35, 37, the pressure above the level in the fresh water area 17 and in the dirty water area 19 can be additionally recorded and a differential pressure measurement can be carried out to determine the two levels. In this case, the negative pressure is added to the gravitational pressure recorded by the measuring sensors 35, 37 in order to obtain the actual gravitational pressure.

[0043] Subsequently, in step 43, the total fill level in the receiving tank 13 is determined by first determining the maximum of the levels in the fresh water area 17 and in the waste water area 19 from the two previously determined levels. Based on this maximum, the total fill level in the receiving tank 13 is then calculated by integrating the receiving tank cross-section along the level height.

[0044] In the subsequent step 44, a check is made to determine whether the level in the fresh water area 17 is less than or equal to a first minimum level and whether the level in the dirty water area 19 is also less than or equal to a second minimum level. This determines whether both the fresh water area 17 and the dirty water area 19 are empty. The minimum levels can therefore also be zero.

[0045] In the event that it is determined in step 44 that both conditions are not met, ie neither the fresh water area 17 nor the dirty water area 19 are empty, the process then proceeds to step 45, in which the volume flow present in the line 21 from the fresh water area 17 to the cleaning device 9 is recorded using the volume flow measuring device 23.

[0046] Subsequently, in step 46, the current filling quantity in the fresh water area 17 is calculated in such a way that the fresh water volume that has flowed out in the meantime, determined using the volume flow measuring device 23, is subtracted from the filling quantity of the fresh water area 17 determined during the previous run through the flow diagram.

[0047] Subsequently, in step 47, a check is carried out to determine whether the conveying device is activated, i.e., whether the suction turbine 33 is switched on and generating a negative pressure in the dirty water area 19. If the suction turbine 33 is not switched on, the method jumps to step 48, in which a check is then carried out to determine whether no fresh water is being conveyed from the fresh water area 17, for example, to the cleaning device 7. This can be done by checking whether the volume flow recorded by the volume flow measuring device 23 is less than or equal to a minimum flow. Furthermore, in step 47, a check is carried out to determine whether the floor cleaning machine 1 is stationary. However, checking whether the machine is stationary is optional. It is also possible to omit this check. If both conditions are met, i.e.,If the volume flow is less than or equal to the minimum flow and the floor cleaning machine 1 is stationary, step 49 determines whether there is an increase in the level in the receiving tank 13. If this is the case, it can be assumed that the fresh water area 17 is being filled by the user, since the machine is not moving and liquid is not being applied to the floor surface 11 and then removed again.

[0048] Therefore, in step 50, the current fill level in the fresh water area 17 is determined by adding the amount resulting from the increase in the level in the receiving tank 13 to the previously determined fill level. It is therefore assumed that the increase in the level in the receiving tank 13 is due to the fact that the user has since added fresh water to the fresh water area 17. Finally, in step 51, the current fill level in the dirty water area 19 is determined as the fill level that had already been previously determined for the dirty water area 19.

[0049] If it is determined in step 47 that the suction turbine 33 is switched on, the method proceeds to step 52, and the current fill level in the dirty water area 19 is determined by first determining the total fill level in the receiving tank 13 from the level present therein, which was already recorded in step 43. Alternatively, the total fill level determined in step 43 can also be used. The current fill level of the fresh water area 17, which was previously determined in step 46, is then subtracted from this total fill level. Finally, the method proceeds to step 53, in which the current fill levels for the fresh water area 17 and the dirty water area 19 are stored.

[0050] If in step 49, ie when checking whether the level in the receiving tank 13 is rising, it is determined that this is not the case, the method proceeds from step 49 to step 54, and the current filling quantity of the dirty water area 19 is set to the amount which results when the current filling quantity of the fresh water area 17 from step 46 is deducted from the total filling quantity of the receiving tank 13, which was determined in step 43.

[0051] If it is finally determined in step 48 that fresh water is being pumped from the fresh water area 17 to the cleaning device 9 or the floor cleaning machine 1 is not at a standstill, the method proceeds from step 48 to step 55, and the current filling quantity in the dirty water area 19 is again determined in such a way that the current filling quantity of the fresh water area 17 is deducted from the total filling quantity determined in step 43.

[0052] Starting from steps 51, 52, 54, 55, the method then always proceeds to step 53 of saving.

[0053] So far, it has been explained how the exemplary embodiment of a method according to the invention proceeds when it is determined in step 44 that neither the fresh water area 17 nor the waste water area 19 is empty. The following describes how the exemplary embodiment proceeds when at least one of these two conditions is not met.

[0054] If it is determined in step 56 that the fresh water area 17 is empty, i.e., the level determined with the sensor 35 is less than or equal to a first minimum value, while at the same time the level in the dirty water area 19 detected with the measurement error 37 is greater than a second minimum value, the method proceeds to step 57. In this step, the current fill level of the fresh water area 17 is set to zero, and subsequently, in step 58, the current fill level of the dirty water area 19 is set to the total fill level determined in step 43. Finally, the method then proceeds to step 53 of saving.

[0055] Alternatively, if it is determined in step 59, as already described, that both the fresh water area 17 and the dirty water area 19 are empty, the method proceeds to step 60, in which the current fill level of the fresh water area 17 is set to zero, and subsequently, in step 61, the current fill level in the dirty water area 19 is also set to zero. The process then returns to step 53, in which the levels are stored.

[0056] If it is finally determined in step 62 that the fresh water area 17 is not empty while the dirty water area 19 is empty, the method proceeds to step 63, in which the current fill level of the fresh water area 17 is set to the total fill level determined in step 43, and then in step 64 the current fill level of the dirty water area 19 is set to zero. In this branch, too, the method then proceeds again to step 53, in which the fill level is saved. This branch is passed during the first run of the method according to this exemplary embodiment, when the floor cleaning machine 1 is started after the fish water area 17 has been filled and no dirty water has yet been taken up. The initial fill level in the fresh water area 17 is then determined here.

[0057] After the previously described steps have been completed depending on the result of the respective queries and "End" has been reached, the process jumps back to "Start" and the steps are run through again.

[0058] From the previous description of the exemplary embodiment of a method according to the invention, it follows that, on the one hand, the filling quantities in the fresh water area 17 and in the dirty water area 19 can be reliably determined during operation of the floor cleaning machine 1. Furthermore, the exemplary embodiment of the method according to the invention also allows for the case in which additional fresh water is added to the fresh water area 17 during an interruption in operation. List of reference symbols:

[0059] 1 Floor cleaning machine 3 Chassis 5 Wheels 7 Cleaning device 9 Brush element 11 Floor area to be cleaned 13 Collection tank 15 Partition wall 17 Fresh water area 19 Dirty water area 21 Line 23 Volume flow measuring device 25 Collection device 27 Squeegee 29 Volume - Squeegee 31 Line 33 Suction turbine 35 Sensor - Fresh water area 37 Sensor - Dirty water area

Claims

1. A method for determining the fill level of a fresh water zone (17) of a floor cleaning machine (1), wherein the floor cleaning machine (1) comprises the fresh water zone (17), a wastewater zone (19), a chassis (3) for moving the floor cleaning machine (1) over a floor surface (11) to be cleaned, a cleaning device (7) for cleaning engagement with the floor surface (11) to be cleaned, wherein the cleaning device (7) is connected to the fresh water zone (17) and is configured to apply fresh water to the floor surface (11) to be cleaned, a collection device (25) for collecting wastewater from the floor surface (11) to be cleaned, wherein the collection device (25) is connected to the wastewater zone (19), and a conveying device (33), which is configured to convey wastewater from the collection device (25) to the wastewater zone (19) in an activated state, wherein the fresh water zone (17) and the wastewater zone (19) are formed in a collection tank (13) and are separated from one another by a flexible partition wall which is designed such that the fresh water zone (17) and the wastewater zone (19) cannot extend, partially or completely, over the cross-section of the collection tank (13), and wherein the method comprises the following steps: detecting the volume flow from the fresh water zone (17) at at least one time between a first time and a second time, wherein the first time is before the second time, and determining the current fill level in the fresh water zone (17) from a previously determined fill level and the detected volume flow.

2. The method according to claim 1, wherein the level in the collection tank (13) is detected and wherein the fill level in the wastewater zone (19) is determined from the current fill level in the fresh water zone (17) and the level in the collection tank (13).

3. The method according to one of claims 1 or 2, wherein it is detected whether the conveying device (33) is in the activated state and / or whether fresh water is being conveyed out of the fresh water zone (17) and / or whether the floor cleaning machine (1) is at a standstill, wherein the level in the collection tank (13) is detected, wherein, when the conveying device (33) is not in the activated state and / or no fresh water is being conveyed out of the fresh water zone (17) and / or the floor cleaning machine (1) is at a standstill, it is determined whether the level in the collection tank (13) is rising, and wherein, when the level in the collection tank (13) rises, the current fill level in the fresh water zone (17) is determined from the rise in the level in the collection tank (13) and the last determined fill level in the fresh water zone (17).

4. The method according to claim 3, wherein the current fill level in the wastewater zone (19) is determined as the last determined fill level in the wastewater zone (19).

5. The method according to claim 3 or 4, wherein, when the level in the collection tank (13) does not rise, the current fill level in the wastewater zone (19) is determined from the level in the collection tank (13) and the last determined fill level in the fresh water zone (17).

6. The method according to one or more of claims 3 to 5, wherein it is detected whether the conveying device (33) is in the activated state, and it is determined whether fresh water is being conveyed out of the fresh water zone (17) and / or whether the floor cleaning machine (1) is at a standstill, wherein the level in the collection tank (13) is detected, and wherein, when the conveying device (33) is not in the activated state and when fresh water is being conveyed out of the fresh water zone (17) and / or the floor cleaning machine (1) is not at a standstill, the current fill level in the wastewater zone (19) is determined from the level in the collection tank (13) and the last determined fill level in the fresh water zone (19).

7. The method according to one or more of claims 2 to 6, wherein the level in the collection tank (13) is detected by detecting the level in the fresh water zone (17) or detecting the level in the wastewater zone (19).

8. The method according to one or more of claims 2 to 6, wherein the level in the collection tank (13) is detected by detecting the level in the fresh water zone (17) and detecting the level in the wastewater zone (19), and wherein the level in the collection tank (13) is determined as the maximum of the level in the fresh water zone (17) and the level in the wastewater zone (19).

9. The method according to claim 7 or 8, wherein the level in the fresh water zone (17) and / or the level in the wastewater zone (19) are detected by detecting the pressure in the base area of the fresh water zone (17) and / or by detecting the pressure in the base area of the wastewater zone (19).

10. The method according to claim 8 or 9, wherein the detection of the volume flow out of the fresh water zone (17) at the at least one time between the first time and the second time and the determination of the current fill level in the fresh water zone (17) takes place when the level in the fresh water zone (17) is greater than a first minimum level and when the level in the wastewater zone (19) is greater than a second minimum level.

11. The method according to one or more of claims 8 to 10, wherein, if the level in the fresh water zone (17) is less than or equal to a first minimum level and if the level in the wastewater zone (19) is greater than a second minimum level, the fill level in the fresh water zone (17) is determined to be minimal and the fill level in the wastewater zone (19) is determined from the level in the collection tank (13) and the cross-section of the collection tank (13).

12. The method according to one or more of claims 8 to 11, wherein, if the level in the fresh water zone (17) is less than or equal to a first minimum level and if the level in the wastewater zone (19) is less than or equal to a second minimum level, the fill level in the fresh water zone (17) is determined to be minimal and the fill level in the wastewater zone (19) is determined to be minimal.

13. The method according to one or more of claims 8 to 12, wherein, if the level in the fresh water zone (17) is greater than a first minimum level and if the level in the wastewater zone (19) is less than or equal to a second minimum level, the fill level in the wastewater zone (19) is determined to be minimal and the fill level in the fresh water zone (17) is determined from the level in the collection tank (13) and the cross-section of the collection tank (13).

14. A floor cleaning machine (1) for carrying out the method according to one of claims 1 to 13, wherein the floor cleaning machine (1) comprises a fresh water zone (17), a wastewater zone (19), a chassis (3) for moving the floor cleaning machine (1) over a floor surface (11) to be cleaned, a cleaning device (7) for cleaning engagement with the floor surface (11) to be cleaned, wherein the cleaning device (7) is connected to the fresh water zone (17) and is configured to apply fresh water to the floor surface (11) to be cleaned, a collection device (25) for collecting wastewater from the floor surface (11) to be cleaned, wherein the collection device (25) is connected to the wastewater zone (19), and a conveying device (33), which is configured to convey wastewater from the collection device (25) to the wastewater zone (19) in an activated state, wherein the fresh water zone (17) and the wastewater zone (19) are designed in a collection tank (13) and are separated from one another by a flexible partition wall which is designed such that the fresh water zone (17) and the wastewater zone (19) cannot extend, partially or completely, over the cross-section of the collection tank (13), wherein the floor cleaning machine is configured to carry out the following steps: detecting the volume flow from the fresh water zone (17) at at least one time between a first time and a second time, wherein the first time is before the second time, and determining the current fill level in the fresh water zone (17) from a previously determined fill level and the detected volume flow.

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