Floor cleaning machine with control unit and method for controlling a floor cleaning machine

Abstract

A floor cleaning machine (1) is shown and described, comprising a frame (3), a chassis (5) arranged on the frame (3) with at least three wheels for moving the floor cleaning machine (1) over a floor surface to be cleaned, wherein the chassis (5) has a drive unit (29) for driving at least one of the wheels (21, 23, 25) so that the floor cleaning machine (1) can be moved in a forward direction over the floor surface to be cleaned, a guide handle arrangement (15) with which the floor cleaning machine (1) can be guided and which is arranged at the rear end of the floor cleaning machine (1) when viewed in the forward direction, and a control unit (35) for controlling the drive unit (29) so that the floor cleaning machine (1) is moved at a predetermined speed in the forward direction over the floor surface to be cleaned, wherein the control unit (35) is configuredto detect a steering angle of the floor cleaning machine (1), and wherein the control unit (35) is configured, upon reaching a predetermined steering angle of the floor cleaning machine (1), to adjust the speed of the floor cleaning machine (1) such that the floor cleaning machine (1) does not exceed a limit speed. Also shown and described is a method (100) for controlling a floor cleaning machine (1).

Description

[0001] The present invention relates to a floor cleaning machine with a control unit and a method for controlling a floor cleaning machine.

[0002] In the prior art, so-called hand-held floor cleaning machines are known that can be guided across a floor surface to be cleaned. These known floor cleaning machines have a chassis with a drive axle for actively moving the machine across the floor surface and a cleaning element assembly with a driven cleaning element designed to engage with the floor surface. Such floor cleaning machines have a control unit with a handle assembly at the rear end (viewed from the forward direction), allowing the user, who walks behind the machine during operation, to control it.

[0003] Both the drive axle of the chassis and the driven cleaning element propel the floor cleaning machine. While the driven chassis typically has an electric drive to power the drive axle, the cleaning element assembly can also propel the machine forward depending on the position of its contact point—that is, the point where the driven cleaning element exerts the greatest pressure on the floor surface to be cleaned—and the rotation of the cleaning element. To operate the floor cleaning machine, a [missing information - likely a specific user or operator] is available.Typically, a user walks behind the floor cleaning machine and operates the drive unit via the control unit, so that the floor cleaning machine is driven forward at a constant speed specified by the user, and the user needs no or very little force to move the floor cleaning machine forward.

[0004] With such floor cleaning machines, it has proven problematic that when the user steers, the deflection of the control unit suddenly exerts a considerable forward force on the user, and the control unit located at the rear of the machine moves quickly forward because it has a large radius to the pivot point around which the machine pivots due to the steering movement.

[0005] This in turn creates the risk that the user loses control of the floor cleaning machine to the extent that the machine continues to move in the direction changed by the steering movement and the user cannot intervene quickly enough if the machine is heading towards an obstacle, so that a collision can easily occur in such a situation.

[0006] Based on the prior art, the object of the present invention is therefore to provide a floor cleaning machine and a method for controlling a floor cleaning machine in which a high level of operational safety is ensured even when driving around curves.

[0007] According to a first aspect of the invention, the aforementioned problem is solved by a floor cleaning machine with the features of claim 1. The floor cleaning machine has a frame and a chassis arranged on the frame, with at least three wheels for moving the floor cleaning machine over a floor surface to be cleaned. The chassis has a drive unit for driving at least one of the wheels, so that the floor cleaning machine can be moved in a forward direction over the floor surface to be cleaned. The floor cleaning machine has a cleaning element arrangement with at least one, preferably driven, cleaning element. The cleaning element is designed to engage with the floor surface to be cleaned.The floor cleaning machine has a guide handle assembly for steering the machine, located at the rear when viewed in the forward direction. The machine also has a control unit for controlling the drive unit, allowing it to move forward at a predetermined speed across the floor area to be cleaned. The control unit is designed to detect the steering angle of the floor cleaning machine and, upon reaching a predetermined angle, to adjust the speed so that the machine does not exceed a limit. Specifically, the speed is adjusted to match the operator's walking speed.

[0008] The floor cleaning machine features a guide handle assembly for operation, located at the rear of the machine when viewed from the forward direction. This assembly serves as a support, allowing the user to hold, control, and steer the machine. Positioning the guide handle at the rear contributes to more precise steering with less effort. The guide handle assembly can be ergonomically designed, resulting in improved comfort and reduced physical strain during operation, which is particularly beneficial during extended use of the floor cleaning machine.

[0009] The guide handle assembly can be equipped with input devices that allow for the control of the floor cleaning machine, thereby increasing user-friendliness. These input devices enable quick and easy adjustment of the machine's functions without requiring the user to change their posture or stop the machine. Machine functions can include, for example, the machine's forward motion, the drive stage of the cleaning element assembly, the dispensing of cleaning fluid, and other settings. The input devices on the guide handle assembly can also be used to adjust the predetermined speed and the maximum speed.

[0010] Furthermore, the floor cleaning machine features a control unit for the drive unit, allowing it to move across the floor surface to be cleaned at a predetermined speed in the forward direction. The ability to control the forward speed via the control unit enables the user to adapt the floor cleaning machine to different floor types and levels of soiling, resulting in improved cleaning quality. Additionally, controlling the predetermined speed via the control unit simplifies operation of the floor cleaning machine, as the user needs to focus less on speed control and can instead concentrate on other aspects of the cleaning process.This can lead to more efficient cleaning and a reduction in physical strain, as a constant speed of movement requires fewer manual adjustments and can therefore reduce fatigue-related errors.

[0011] The control unit is designed to detect the steering angle of the floor cleaning machine and, upon reaching a predetermined steering angle, to adjust the machine's speed to prevent it from exceeding a limit. By detecting the steering angle, it is possible to recognize when the floor cleaning machine is turning. The steering angle directly influences the radius of the turn. A larger steering angle results in a smaller turning radius, meaning the floor cleaning machine makes a tighter turn. Conversely, a smaller steering angle results in a larger turning radius, and the floor cleaning machine makes a wider, less tight turn.

[0012] When a user guides the floor cleaning machine around a curve, a forward force is exerted on the user in the machine described above. The guide handle assembly suddenly moves forward away from the user at high speed while maintaining the speed at which the drive axle is being driven. This results from the large radius of the guide handle assembly relative to the pivot point around which the machine pivots due to the steering movement. As previously explained, this poses significant hazards.

[0013] In practical terms, this means that the stability and safety of the floor cleaning machine when negotiating curves depend significantly on its speed. If the speed is too high, the floor cleaning machine becomes more difficult to control, and there is even an increased risk of collisions with obstacles. Therefore, the control unit is designed to adjust the speed of the floor cleaning machine so that it does not exceed a limit. This limit can be a fixed, preset speed value chosen to ensure that the machine's movements remain controllable through steering input. Alternatively, the limit can be directly proportional to the preset speed. This has the advantage of ensuring that the limit is aligned with the user-defined speed.

[0014] The reduction in speed upon reaching a predetermined steering angle, implemented by the floor cleaning machine's control unit, minimizes the forces acting on the user while turning and reduces the forward movement of the handlebar to a safe level, thus maintaining control of the floor cleaning machine even when cornering. As a result, the user can comfortably keep pace with the floor cleaning machine without having to move excessively fast or make abrupt movements. This significantly contributes to user safety and cleaning effectiveness.

[0015] By reducing the speed upon reaching the predetermined steering angle, simplified and more resource-efficient control of the floor cleaning machine is achieved. This eliminates the need for constant adjustments to the machine's speed against the steering angle. Instead, the control unit can use reaching the predetermined steering angle as a clearly defined trigger signal to reduce speed. Once the predetermined steering angle is reached, the speed is reduced. This minimizes the need for computationally intensive adjustments and results in more stable and predictable operation of the floor cleaning machine.

[0016] The speed of a floor cleaning machine can be reduced by decreasing the forward motion of the drive unit or by applying the brakes. A reduction in forward motion can be achieved by adjusting the power output of the drive unit, which means decreasing the energy supplied to the drive unit. Alternatively, the brakes can be used to achieve a rapid reduction in speed, especially when an immediate reduction is required. This can be done using mechanical brakes that act directly on the wheels. It is also conceivable to combine both methods to achieve optimal control over the speed of the floor cleaning machine.

[0017] The limiting speed also has the advantage that the control unit does not need to adjust the speed of the floor cleaning machine when the predetermined steering angle is reached, provided the speed of the floor cleaning machine has already been selected to ensure safe cornering. This means that at sufficiently low speeds, the floor cleaning machine does not need to make any adjustments while cornering, as the forces involved in cornering are correspondingly low at these speeds.

[0018] In summary, it can be stated that according to the invention a floor cleaning machine is provided with a control unit that makes it possible to automatically adjust the speed of the floor cleaning machine in curves in order to reduce the physical strain on the user and to ensure safe and comfortable operation.

[0019] In one embodiment, the chassis has at least one drive axle driven by the drive unit, comprising a first wheel and a second wheel. The drive unit includes at least one electric motor that can directly drive the drive axle or the wheels, enabling the floor cleaning machine to move forward across the floor surface to be cleaned. The use of two wheels on the drive axle ensures stable and smooth movement of the floor cleaning machine. This also allows for improved maneuverability, particularly when cornering or encountering obstacles. The drive unit enables precise control of the speed and movement of the floor cleaning machine, contributing to improved cleaning quality.

[0020] In one embodiment, the control unit is configured to determine the rotational speed of at least two wheels of the chassis and to determine the predetermined steering angle from the difference in rotational speed between the two wheels. For this purpose, speed sensors can be attached to the wheels. These sensors, often Hall effect or optical sensors, can measure the revolutions of the wheels per unit of time and send this data to the control unit. The control unit can process the information to determine the difference in rotational speed between the wheels, with a greater difference indicating a greater steering angle. Determining the steering angle from the difference in rotational speed between two wheels of the floor cleaning machine is based on the principle of differential control.A greater difference in rotational speed causes the faster wheel to travel a greater distance than the slower one, thus steering the floor cleaning machine towards the slower wheel. The steering angle can be determined by calculating the turning radius from the ratio of the wheel spacing to the speeds or rotational speeds of the individual wheels. This allows for precise determination of the steering angle, enabling rapid and accurate speed adjustments of the floor cleaning machine once the predetermined steering angle has been determined.

[0021] In one embodiment, the chassis has at least one third wheel that can pivot about a vertical pivot axis. The third wheel is preferably the rearmost of the at least three wheels in the forward direction. A third wheel that pivots about the vertical pivot axis can significantly improve the maneuverability of the floor cleaning machine, as it allows for greater steering flexibility. The third wheel can rotate independently of the other wheels, enabling the floor cleaning machine to turn on the spot and navigate tight curves with a smaller radius. The third wheel also allows for flexibility in determining the steering angle, as this can also be determined by rotating the third wheel about the vertical pivot axis. With the third wheel, immediate changes in the orientation and speed of the floor cleaning machine can be achieved, resulting in more intuitive and responsive control.This can contribute to the overall performance and safety when operating the floor cleaning machine.

[0022] In one embodiment, the control unit is configured to detect the swivel angle of the third wheel and determine the predetermined steering angle based on this angle. Rotary potentiometers mounted on the swivel axis, electronic angle sensors, or infrared or magnetic Hall sensors that determine the wheel's angular position can be used to detect the swivel angle of the third wheel. Determining the swivel angle of the third wheel has the advantage that only the swivel angle of one wheel needs to be determined to calculate the steering angle of the floor cleaning machine. This allows for a smaller number of components in the floor cleaning machine and a simpler design.

[0023] In one embodiment, the control unit includes a swivel angle detection unit for detecting the swivel angle of the third wheel, wherein the swivel angle detection unit comprises at least one magnet unit and an angle element. The magnet unit is connected to one of the frame components and the third wheel, and the angle element is connected to the other of the frame components and the third wheel. The magnet unit and the angle element are arranged such that the attainment of the predetermined steering angle is detected by the magnet unit by the angle element influencing a magnetic field generated by the magnet unit upon reaching the predetermined steering angle, thereby generating a trigger signal from the magnet unit. The magnet unit may include an electromagnet for generating the magnetic field.The angle element can be uniformly shaped and made of a magnetically conductive material capable of influencing the magnetic field generated by the magnet unit. This allows the swivel angle detection unit to determine when the angle element has been moved. Influence of the angle element on the magnetic field is understood to mean any change in the magnetic flux. This could be achieved by the angle element being swung out of or into the magnetic field when the predetermined steering angle is reached. Alternatively, the angle element could be irregularly shaped with sections that influence the magnetic field differently, allowing the swivel angle to be determined by the varying influence of these sections. This enables a particularly simple and robust swivel angle detection system for the third wheel.

[0024] In one embodiment, the control unit is configured to increase the speed of the floor cleaning machine when the steering angle falls below the predetermined limit, preferably until the predetermined speed is reached. By increasing the speed when the steering angle falls below the predetermined limit, the floor cleaning machine is automatically accelerated, preferably to the predetermined speed, once it has completed a turn or is no longer turning. This ensures that the speed is only reduced during turns to minimize the centrifugal force acting on the operator. This automatic speed adjustment enhances the safety and ease of operation of the floor cleaning machine by reducing the need for manual intervention.

[0025] In one embodiment, the limiting speed is a maximum of 75%, preferably a maximum of 50%, and more preferably a maximum of 25% of the predetermined limiting speed of the floor cleaning machine. By linking the limiting speed to the predetermined speed as a percentage, a relative speed reduction can be achieved depending on the predetermined speed. This results in an individualized speed reduction, where the limiting speed is reduced relative to the predetermined speed, so that a high predetermined speed results in a relatively high limiting speed.

[0026] In one embodiment, the control unit is configured, when the predetermined steering angle is reached, to control the drive unit depending on, preferably proportionally, and more preferably directly proportionally, to the steering angle of the floor cleaning machine. Proportional control of the drive unit depending on the steering angle means that the change in drive power is in a fixed ratio to the steering angle. This allows the changes in drive power to depend directly on the steering angle, so that at larger steering angles the speed is reduced more significantly than at smaller steering angles. This type of control enables a finer and more precise adjustment of the floor cleaning machine's speed to the cleaning environment.

[0027] According to a second aspect of the invention, the aforementioned problem is solved by a method with the features of claim 10. The method is for controlling a floor cleaning machine, comprising the following steps: Driving the floor cleaning machine at a predetermined speed. Detecting the steering angle of the floor cleaning machine using a steering angle detection system. Comparing the steering angle with a predetermined steering angle. Adjusting the speed of the floor cleaning machine such that the speed of the floor cleaning machine does not exceed a limit speed when the steering angle exceeds the predetermined steering angle.

[0028] The present invention will now be explained with reference to a drawing showing only one preferred embodiment, in which Figure 1 shows a schematic view of an embodiment of a floor cleaning machine according to the invention, Figure 2 shows a schematic partial view of the embodiment of the floor cleaning machine according to the invention. Figure 1 Figure 3 shows a schematic partial view of the exemplary embodiment of the floor cleaning machine according to the invention. Figure 1 and 2 shows, and Figure 4 shows a schematic representation of an embodiment of a method according to the invention.

[0029] Figure 1Figure 1 shows a schematic view of an embodiment of a floor cleaning machine 1 according to the invention. The floor cleaning machine 1 has a frame 3 and a chassis 5 arranged on the frame 3 for moving the floor cleaning machine 1 over a floor surface to be cleaned. The frame 3 is understood to be the stationary part of the floor cleaning machine 1 that is connected to the chassis 5. The frame 3 can, for example, be made of a steel or aluminum construction or of a composite material.

[0030] Furthermore, the floor cleaning machine 1 has a cleaning element arrangement 7 with a driven cleaning element 9, wherein the cleaning element 9 is designed to engage with the floor surface to be cleaned. The cleaning element 9 is driven by a cleaning drive unit 11. For example, the cleaning element 9 can be a brush, in which case the engagement elements are bristles whose free ends engage with the floor surface to be cleaned. However, it is equally conceivable that the cleaning element 9 is a so-called pad, in which the engagement element is formed by a flat material provided on the pad, the surface of which comes into contact with the floor surface to be cleaned.

[0031] The floor cleaning machine 1 has a housing 13 for enclosing the floor cleaning machine 1 and a guide handle assembly 15 for guiding the floor cleaning machine 1 over the floor surface to be cleaned. The housing 13 can accommodate a fresh water tank for receiving fresh water and a dirty water tank for receiving dirty water.

[0032] The floor cleaning machine 1 is guided by a user via the guide handle assembly 15, which is located at the rear of the machine when viewed in the forward direction. The guide handle assembly 15 serves as a support, allowing the user to hold, control, and steer the floor cleaning machine 1. Its rearward placement enables precise steering with less effort. The guide handle assembly 15 can be ergonomically designed, resulting in improved comfort and reduced physical strain during operation, which is particularly advantageous during extended use of the floor cleaning machine 1.

[0033] Input devices can be arranged on the guide handle assembly 15, enabling control of the floor cleaning machine 1 and thus increasing user-friendliness. These input devices allow for simple and quick adjustment of the floor cleaning machine's functions without requiring the user to change their working posture or stop the machine. The machine functions can include, for example, the forward movement of the floor cleaning machine 1, the drive stage of the cleaning element assembly 7, the dispensing of cleaning fluid, and other settings. It can also be provided that the predetermined speed and the limit speed can be adjusted via the input devices on the guide handle assembly 15.

[0034] The chassis 5 has a first chassis axle 17 and a second chassis axle 19, with the first chassis axle 17 being, as in the Figures 2 and 3The figure shows a first wheel 21 and a second wheel 23 in the form of two opposing wheels, and a third wheel 25 in the form of a guide wheel is arranged on the second chassis axle 19. The third wheel 25 is pivotable about a vertical pivot axis 27. In the forward direction, the third wheel 25 is the rearmost of the three wheels 21, 23, 25. A third wheel 25 that pivots about the vertical pivot axis 27 can significantly improve the maneuverability of the floor cleaning machine 1, as it allows greater flexibility in steering. The third wheel 25 can rotate independently of the other wheels, enabling the floor cleaning machine 1 to turn on the spot and navigate tight curves with a smaller radius. The third wheel 25 also allows for flexibility in determining the steering angle, as this can also be determined from the pivot angle of the third wheel 25 about the vertical pivot axis 27.The third wheel 25 allows for immediate changes in the orientation and speed of the floor cleaning machine 1, resulting in more intuitive and responsive control. This can contribute to the overall efficiency and safety of operating the floor cleaning machine 1.

[0035] Figure 2 shows a schematic partial view of the exemplary embodiment of the floor cleaning machine 1 according to the invention. Figure 1The chassis 5 has a drive unit 29 for driving a drive axle assembly 31. The drive axle assembly 31 drives the first wheel 21 and the second wheel 23. The drive unit 29 has an electric motor 33 that can directly drive the drive axle assembly 31, enabling the floor cleaning machine 1 to move forward over the floor surface to be cleaned. In an alternative embodiment, the first wheel 21 and the second wheel 23 each have their own electric motor 33. The use of two wheels 21, 23 on the drive axle assembly 31 ensures stable and smooth movement of the floor cleaning machine 1. The use of two wheels 21, 23 on the drive axle assembly 31 also allows for better maneuverability of the floor cleaning machine 1, particularly when cornering or encountering obstacles.The drive axis arrangement 31 enables precise control of the speed and movement of the floor cleaning machine 1, which contributes to improved cleaning quality.

[0036] The floor cleaning machine 1, as shown in Figure 3 shown is a control unit 35 for controlling the drive unit 29, so that the floor cleaning machine 1 is moved at a predetermined speed in the forward direction over the floor area to be cleaned.

[0037] The control unit 35 has a swivel angle detection unit 37 for detecting a swivel angle of the third wheel 25, wherein the swivel angle detection unit 37 comprises a magnetic unit 39 and an angle element 41. The swivel angle detection unit 37 can also be configured as a separate unit and communicate with the control unit 35. In the present embodiment, the magnetic unit 39 is connected to the frame 3 and the angle element 41 is connected to the third wheel 25. In an alternative embodiment, the magnetic unit 39 is connected to the third wheel 25 and the angle element 41 is connected to the frame 3. The swivel angle detection unit 37 is referred to with reference to Figure 3 explained in more detail below.

[0038] Figure 3 shows a schematic partial view of the exemplary embodiment of the floor cleaning machine 1 according to the invention. Figure 1 and 2The angle element 41 has a first circular segment 43 and a second circular segment 45. The first circular segment 43 and the second circular segment 45 are dimensioned such that they represent a first pivot angle range 47 and a second pivot angle range 49 of the pivot angle of the third wheel 25.

[0039] The first swivel angle range 47 serves to determine the predetermined steering angle in a forward direction of the third wheel 25. The forward direction of the third wheel 25 is the orientation that the third wheel 25 assumes during forward travel of the floor cleaning machine 1. The second swivel angle range 49 serves to determine the predetermined steering angle in a reverse direction of the third wheel 25. The reverse direction of the third wheel 25 is the orientation that the third wheel 25 assumes during reverse travel of the floor cleaning machine 1. In this embodiment, the second circular segment 45 is wider than the first circular segment 43. As a result, the second swivel angle range 49 is larger than the first swivel angle range 47. A floor cleaning machine 1 is typically driven at a lower speed in a reverse direction.This allows the second swivel angle range 49 to be selected to be correspondingly larger. This enables separate, predetermined steering angles to be defined for the forward and reverse directions.

[0040] The following explains the operation of the swivel angle detection unit 37 only in the forward direction. The operation of the swivel angle detection unit 37 in the reverse direction is analogous.

[0041] The predetermined steering angle is defined by the dimensions of the first circular segment 43, whereby the predetermined steering angle lies outside the first swivel angle range 47. The magnetic unit 39 and the angle element 41 are arranged such that the attainment of the predetermined steering angle is detected by the magnetic unit 39 by the angle element 41 influencing a magnetic field generated by the magnetic unit 39 upon reaching the predetermined steering angle, thus generating a trigger signal from the magnetic unit 39. The magnetic unit 39 may include an electromagnet for generating the magnetic field. The angle element 41 has a magnetically conductive material capable of influencing the magnetic field generated by the magnetic unit 39, so that the swivel angle detection unit 37 can determine when the angle element 41 has been moved.The influence of the angle element 41 on the magnetic field is understood to mean any change in the magnetic flux. In the present embodiment, the angle element 41 influences the magnetic field of the magnet unit 39 by pivoting the angle element 41 out of the magnetic field with the first circular segment 43 when the predetermined steering angle is reached.

[0042] In an alternative embodiment, the angle element 41 influences the magnetic field of the magnet unit 39 by pivoting the angle element 41 into the magnetic field with the first circular segment 43 when the predetermined steering angle is reached. It is also conceivable that the angle element 41 is non-uniformly shaped and has sections that influence the magnetic field differently, so that the pivot angle is determined by the different influences on the sections of the angle element 41. This enables a particularly simple and robust detection of the pivot angle of the third wheel 25.

[0043] As already mentioned, the control unit 35 is configured to detect the steering angle of the floor cleaning machine 1 and, upon reaching the predetermined steering angle of the floor cleaning machine 1, to adjust the speed of the floor cleaning machine 1 so that the floor cleaning machine 1 does not exceed a limit speed. The operation of the control unit 35 and the speed adjustment is described below with reference to the Figure 4 The procedure described in section 100 is described.

[0044] Figures 4 Figure 1 shows a schematic representation of an embodiment of a method 100 according to the invention. The method 100 has a first step 101, a second step 102, a third step 103 and a fourth step 104.

[0045] The first step 101 of procedure 100 involves driving the floor cleaning machine 1 at a predetermined speed. The ability to control the speed in the forward direction via the control unit 35 allows the user to adapt the floor cleaning machine 1 to different floor types and levels of soiling, resulting in improved cleaning quality. Furthermore, controlling the predetermined speed via the control unit 35 simplifies the operation of the floor cleaning machine 1, as the user needs to pay less attention to speed control and can instead concentrate on other aspects of cleaning. This can lead to more efficient cleaning and a reduction in physical strain, since a constant speed of movement requires fewer manual adjustments and can thus reduce fatigue-related errors.

[0046] The second step 102 of the procedure 100 involves detecting the steering angle of the floor cleaning machine 1 using steering angle detection. By detecting the steering angle, it is possible to recognize when the floor cleaning machine 1 is turning. The steering angle directly influences the radius of the turn taken by the floor cleaning machine 1. A larger steering angle results in a smaller turning radius, meaning that the floor cleaning machine 1 makes a tighter turn. Conversely, a smaller steering angle results in a larger turning radius, and the floor cleaning machine 1 makes a wider, less tight turn.

[0047] In accordance with the present invention, a steering angle is already detected if it is merely determined whether the steering angle reaches a predetermined steering angle. According to the invention, it is not necessary to detect the exact pivot angle by which the third wheel 25 is pivoted about the vertical pivot axis 27.

[0048] Steering angle detection can, for example, be used in the Figures 2 and 3The steering angle detection unit 37 shown is used. Alternatively, the steering angle detection can include rotational speed detection of the first wheel 21 and the second wheel 23. For this purpose, the control unit 35 can be configured to determine the rotational speed of the first wheel 21 and the second wheel 23 of the chassis 5 in order to determine, based on a difference in rotational speed between the two wheels 21 and 23 of the chassis 5, whether the predetermined steering angle has been reached. For this purpose, rotational speed sensors can be attached to the wheels 21 and 23. These sensors, often Hall sensors or optical sensors, can measure the revolutions of the wheels 21 and 23 per unit of time and send this data to the control unit 35. The control unit 35 can process the information to determine the difference in rotational speed between the wheels 21 and 23, with a larger difference in rotational speed resulting in a larger steering angle.Determining the steering angle from the rotational speed difference between two wheels 21 and 23 of the floor cleaning machine 1 is based on the principle of differential control. A greater rotational speed difference causes the faster wheel to travel a greater distance than the slower wheel, thus steering the floor cleaning machine 1 towards the slower wheel. The steering angle can be determined by calculating the turning radius from the ratio of the wheel spacing between wheels 21 and 23 and the speeds or rotational speeds of the individual wheels 21 and 23. This allows for a precise determination of the steering angle, enabling rapid and accurate speed adjustment of the floor cleaning machine 1 once the predetermined steering angle has been determined.

[0049] The third step 103 of procedure 100 involves comparing the steering angle with a predetermined steering angle. If the floor cleaning machine 1 turns a curve with a steering angle greater than the predetermined steering angle, there is a risk that, due to a sudden forward force and a high-speed forward-moving guide handle assembly 15, the user may at least temporarily lose control of the floor cleaning machine 1. However, this is highly dependent on the speed at which the floor cleaning machine 1 is moving.

[0050] In practical terms, this means that the stability and safety of the floor cleaning machine 1 when driving through curves depend significantly on the speed control.

[0051] Then, if the result of the third step 103 is that the steering angle has not reached or exceeded the predetermined steering angle (path n), the procedure 100 continues with the first step 101, driving the floor cleaning machine 1 at the predetermined speed. If the result of the third step 103 is that the steering angle has exceeded the predetermined steering angle (path y), the procedure 100 continues with the fourth step 104.

[0052] The fourth step 104 of the procedure 100 involves adjusting the speed of the floor cleaning machine 1 such that the speed of the floor cleaning machine 1 is adjusted so that a limit speed is not exceeded when the steering angle exceeds the predetermined steering angle. Adjusting the speed upon reaching a predetermined steering angle by the control unit 35 of the floor cleaning machine 1 makes it possible to reduce the forces acting on the user during cornering and the rapid forward movement of the guide handle assembly 15 to a safe level, so that the user maintains control over the floor cleaning machine 1 even when cornering. This is particularly the case when the limit speed is sufficiently low. As a result, the user can comfortably keep pace with the floor cleaning machine 1 without having to move excessively fast or make abrupt movements.This contributes significantly to user safety and cleaning effectiveness.

[0053] Accordingly, the speed is reduced when the predetermined steering angle is reached and the current speed of the floor cleaning machine 1 exceeds the limit speed. If either the steering angle is not reached or the speed of the floor cleaning machine 1 does not exceed the limit speed, the speed of the floor cleaning machine 1 is at least not reduced, so that the floor cleaning machine 1 continues to operate at the predetermined speed.

[0054] By adjusting the speed upon reaching the predetermined steering angle, a simplified and resource-efficient control of the floor cleaning machine 1 is achieved, eliminating the need for constant comparison of the machine's current speed with the steering angle. Instead, the control unit 35 can use the attainment of the predetermined steering angle as a clearly defined trigger signal to reduce the speed. Once the predetermined steering angle is reached, the speed is reduced if the current speed exceeds the limit. This reduces the need for computationally intensive adjustments and results in more stable and predictable operation of the floor cleaning machine 1. Furthermore, this approach minimizes the energy consumption of the floor cleaning machine 1 and reduces mechanical stress caused by frequent speed adjustments.

[0055] The speed of the floor cleaning machine 1 can be reduced by reducing the forward motion of the drive unit 29 or by applying a brake on the floor cleaning machine 1. A reduction in forward motion can be achieved by adjusting the power output to the electric motor 33, which means reducing the energy supply to the electric motor 33. Alternatively, the brake can be used to achieve a rapid reduction in speed, especially when an immediate reduction in speed is required. This can be done using mechanical brakes that act directly on the wheels 21, 23, and 25. It is also conceivable that both methods can be combined to achieve optimal control over the speed of the floor cleaning machine 1.

[0056] The limiting speed is a maximum of 75%, preferably a maximum of 50%, and more preferably a maximum of 25% of the predetermined limiting speed of the floor cleaning machine 1. By coupling the limiting speed to the predetermined speed as a percentage, a relative speed reduction can be achieved depending on the predetermined speed. This results in an individualized speed reduction, where the limiting speed is reduced relative to the predetermined speed, so that a high predetermined speed results in a relatively high limiting speed.

[0057] It can also be provided that the control unit 35 is configured, when the predetermined steering angle is reached, to control the drive unit 29 depending on, preferably proportionally, and more preferably directly proportionally, to the steering angle of the floor cleaning machine 1. Proportional control of the drive unit 29 depending on the steering angle means that the change in drive power is in a fixed, continuous ratio to the steering angle. This, however, requires that the steering angle be measured absolutely, and not merely, as previously described, that it be determined whether the steering angle has reached the predetermined steering angle. This allows the changes in drive power to depend directly on the steering angle, so that at a larger steering angle the speed is reduced more than at smaller steering angles.This type of control allows for a finer and more precise adjustment of the speed of the floor cleaning machine 1 to the cleaning environment by supporting a higher speed in straight or wide areas and a reduced speed in narrow, complex areas.

[0058] In principle, steps 101 to 104 can be performed sequentially. However, the invention is not limited to performing steps 101 to 104 sequentially. It is also possible to perform at least some of these steps multiple times and in parallel, or partially overlapping in time.

[0059] In particular, steps 101 and 102 or 103 can be performed in parallel, so that the steering angle is measured while the floor cleaning machine 1 is driven at the predetermined speed, or the steering angle is compared with the predetermined steering angle while the floor cleaning machine 1 continues to be driven at the predetermined speed. Then, if the third step 103 determines that the steering angle has reached or exceeded the predetermined steering angle (path y), the procedure 100 proceeds to the fourth step 104, adjusting the speed.

[0060] As in Figure 4As indicated by the arrow from the fourth step 104 to the second step 102, the method 100 can provide that, after or simultaneously with the reduction of speed in the fourth step 104, the steering angle is again detected and compared with the predetermined steering angle. This allows the control unit 35 to increase the speed of the floor cleaning machine 1 if the steering angle falls below the predetermined angle, preferably until the predetermined speed is reached. By increasing the speed when the steering angle falls below the predetermined angle, the floor cleaning machine 1 is automatically accelerated, preferably to the predetermined speed, once the floor cleaning machine 1 has completed its turn or is no longer turning. This ensures that the speed is only reduced during turns, thus minimizing the force exerted on the user.This allows for automatic speed adjustment, which increases the safety and ease of use of the floor cleaning machine 1 by reducing manual intervention. Reference symbol list:

[0061] 1 Floor cleaning machine 3 Frame 5 Chassis 7 Cleaning element assembly 9 Cleaning element 11 Cleaning drive unit 13 Housing 15 Guide handle assembly 17 First drive axle 19 Second drive axle 21 First wheel 23 Second wheel 25 Third wheel 27 Vertical swivel axle 29 Drive unit 31 Drive axle assembly 33 Electric motor 35 Control unit 37 Swivel angle detection unit 39 Magnet unit 41 Angle element 43 First circular segment section 45 Second circular segment section 47 First swivel angle range 49 Second swivel angle range 100Procedure 101First step 102Second step 103Third step 104Fourth step

Claims

1. Floor cleaning machine (1) comprising a frame (3), a chassis (5) arranged on the frame (3) with at least three wheels (21, 23, 25) for moving the floor cleaning machine (1) over a floor surface to be cleaned, wherein the chassis (5) has a drive unit (29) for driving at least one of the wheels (21, 23, 25) so that the floor cleaning machine (1) can be moved in a forward direction over the floor surface to be cleaned, a cleaning element arrangement (7) with at least one, preferably driven, cleaning element (9), wherein the cleaning element (9) is designed to engage with the floor surface to be cleaned, a guide handle arrangement (15) with which the floor cleaning machine (1) can be guided and which is arranged at the rear end of the floor cleaning machine (1) when viewed in the forward direction, and a control unit (35) for controlling the drive unit (29).so that the floor cleaning machine (1) is moved at a predetermined speed in the forward direction over the floor area to be cleaned, wherein the control unit (35) is configured to detect a steering angle of the floor cleaning machine (1), and wherein the control unit (35) is configured, upon reaching a predetermined steering angle of the floor cleaning machine (1), to adjust the speed of the floor cleaning machine (1) such that the floor cleaning machine (1) does not exceed a limit speed.

2. Floor cleaning machine (1) according to claim 1, wherein the chassis (5) has at least one drive axle (31) driven by the drive unit (29) with a first wheel (21) and a second wheel (23).

3. Floor cleaning machine (1) according to claim 1 or 2, wherein the control unit (35) is configured to determine a rotational speed of at least two wheels (21, 23, 25) of the chassis (5) and to determine the predetermined steering angle by a difference in rotational speed of the two wheels (21, 23, 25) of the chassis (5).

4. Floor cleaning machine (1) according to claim 2 or 3, wherein the chassis (5) has at least one third wheel (25) which is pivotable about a vertical pivot axis (27).

5. Floor cleaning machine (1) according to claim 4, wherein the control unit (35) is configured to detect a swivel angle of the third wheel (25) and to determine the predetermined steering angle based on the swivel angle of the third wheel (25).

6. Floor cleaning machine (1) according to claim 4 or 5, wherein the control unit (35) has a swivel angle detection unit (37) for detecting the swivel angle of the third wheel (25), wherein the swivel angle detection unit (37) has at least one magnet unit (39) and an angle element (41), wherein the magnet unit (39) is connected to one of the frame (3) and the third wheel (25) and the angle element (41) is connected to the other of the frame (3) and the third wheel (25), wherein the magnet unit (39) and the angle element (41) are arranged such that the attainment of the predetermined steering angle is detected by the magnet unit (39) by the angle element (41) influencing a magnetic field generated by the magnet unit (39) when the predetermined steering angle is reached, so that a trigger signal is generated by the magnet unit (39).

7. Floor cleaning machine (1) according to one of the preceding claims, wherein the control unit (35) is configured to increase the speed of the floor cleaning machine (1) when the predetermined steering angle of the floor cleaning machine (1) is undershot, preferably until a predetermined speed is reached.

8. Floor cleaning machine (1) according to one of the preceding claims, wherein the limiting speed is a maximum of 75%, preferably a maximum of 50%, further preferably a maximum of 25%, of the predetermined speed of the floor cleaning machine (1).

9. Floor cleaning machine (1) according to one of the preceding claims, wherein the control unit (35) is configured, when the predetermined steering angle is reached, to control the drive unit (29) depending on, preferably proportionally, further preferably directly proportionally, to a steering angle of the floor cleaning machine (1).

10. Method (100) for controlling a floor cleaning machine (1), comprising the following steps: driving (101) the floor cleaning machine (1) at a predetermined speed, detecting (102) a steering angle of the floor cleaning machine (1) with a steering angle detection system, comparing (103) the steering angle with a predetermined steering angle, adjusting (104) the speed of the floor cleaning machine (1) such that the speed of the floor cleaning machine (1) does not exceed a limit speed when the steering angle exceeds the predetermined steering angle.

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