Method for detecting and removing a blockage

Abstract

A method for detecting and clearing a blockage in an air duct of a mobile, self-propelled device comprising a suction blower (8) and a brush roller (2) and performing a cleaning task is described, comprising the following method steps: determining at least one operating parameter of the suction blower (8) or a sensor reading; comparing the operating parameter with a predetermined threshold or evaluating the sensor reading; switching off the suction blower (8) if the operating parameter exceeds the predetermined threshold or the sensor reading indicates a blockage; rotating the brush roller (2) backwards; reversing the device; and switching on the suction blower (8) and subsequently determining the current operating parameter of the suction blower (8) or the current sensor reading.

Description

[0001] The invention relates to a method for detecting and repairing a blockage in an air duct of a mobile, self-driving device, in particular a floor cleaning device such as a cleaning robot, a mobile, self-driving device, a computer program product and a computer-readable data carrier.

[0002] Floor cleaning devices, such as robotic cleaners, are designed to relieve users of the tedious task of removing dust and dirt from their floors. Besides sweeping and mopping, vacuuming is a particularly effective cleaning function for removing dust. A suction fan generates an airflow that draws dust particles through the robot's suction opening and into its dustbin. Inside the dustbin, a filter separates the dust particles from the airflow, which then remain in the dustbin. The airflow continues to the fan and is subsequently expelled from the robot.

[0003] It can happen that an autonomous cleaning robot sucks up objects that clog its air ducts, block the suction nozzle, and / or cover the filter. Such objects can be cloths and / or socks, plastic bags, or similar items. If the airflow is obstructed, the suction fan lacks the air it needs to draw in. This creates increased negative pressure at the fan, reducing the (air) resistance for the fan, causing the fan speed to increase, while simultaneously lacking cooling air. This can result in critical overheating of the fan's electronics, potentially leading to a failure of the robot's electronics or at least of the fan's electronics. Even cleaning robots with camera-based object recognition cannot detect and avoid every problematic object on the floor. Sensors that measure the dustbin's fill level may also be unaffected by such an incident.

[0004] Cleaning robots often use radial fans, which are usually driven by brushless motors. These fans are located downstream of the filter on the robot's dustbin and draw air through the filter, the dustbin itself, the suction channel, and finally the suction nozzle. Therefore, the fans are always affected if a blockage occurs in any part of this airflow path.

[0005] The object of the invention is to provide a method for detecting and resolving a blockage in an air duct, in which a blocked air duct can be detected early, the blower can be switched off and the blockage can be resolved autonomously.

[0006] This problem is solved by a method for detecting and remedying a blockage in an air duct of a mobile, self-propelled device with the features of claim 1. Advantageous embodiments and further developments are the subject of the dependent claims.

[0007] According to the invention, a method for detecting and clearing a blockage in an air duct of a mobile, self-propelled device comprising a suction blower and a brush roller and performing a cleaning task comprises the following method steps: Determine at least one operating parameter of the suction fan or a sensor reading, compare the operating parameter with a predefined threshold or evaluate the sensor reading, switch off the suction fan if the operating parameter exceeds the predefined threshold or the sensor reading indicates a blockage, rotate the brush roller backward, reverse the device, switch on the suction fan, and subsequently determine the current operating parameter of the suction fan or the current sensor reading. The current operating parameter or current sensor reading is, in particular, the same (but updated) value that was initially determined beforehand in the process.

[0008] In this case, the device independently detects the blockage in the air duct by evaluating its fan parameters or sensor readings, deactivates the fan itself, and attempts to clear the blockage autonomously. This proactive approach prevents permanent damage to the fan and the device. Ideally, the device can resolve the situation on its own without user intervention.

[0009] The following advantages can be achieved with the method according to the invention: A blockage or obstruction of the air duct can be detected, thus preventing damage to the blower or the device. The device may even be able to clear the blockage itself during its self-clearing attempt, eliminating the need for user intervention. Optionally, the device can inform a user about the blockage, for example via an app, so that even users who are not present are notified of the malfunction.

[0010] A mobile, self-propelled device is understood to be, in particular, a floor cleaning device that autonomously cleans floor surfaces, for example, in the home. This includes, among other things, vacuuming devices and combination devices, i.e., robotic vacuums and mops. These devices operate (during cleaning mode) preferably with little or no user intervention. For example, the device automatically moves to a designated room to clean the floor according to a pre-programmed cleaning strategy.

[0011] Preferably, the device is a cleaning robot equipped with a suction nozzle featuring a brush roller and a suction fan. The robot may also include a side brush and / or a wet cleaning module. For environmental mapping and obstacle detection, the robot is equipped with navigation sensors (e.g., LiDAR sensor, camera, and / or wall-following sensor). A controller is responsible for processing the sensor data, planning cleaning missions, determining the cleaning routes, and controlling the actuators. A drive system enables the device to move in a controlled manner.

[0012] The device's suction fan is positioned downstream of a dust box containing a filter. Air, including entrained dust particles, is drawn in by the fan and enters the device through a suction nozzle. It then travels through air ducts to the dust box and filter, and finally, cleaned, back to the fan before exiting the device. A control unit within the device can operate the suction fan and monitor and process its current operating parameters, such as current, voltage, and / or speed. At the end of a cleaning cycle or in the event of a malfunction, the control unit can deactivate the fan.

[0013] There are two possible control methods for the suction blower: power control or speed control. With power control, a power value (current, voltage) is adjusted so that the blower maintains a nearly constant, predetermined power consumption. With speed control, the blower is controlled to achieve a nearly constant, predetermined speed. If a blockage occurs in front of a power-controlled blower, its speed increases due to the reduced air resistance at the blower blades. This can be clearly detected by measuring the speed. Conversely, if a blockage occurs in front of a speed-controlled blower, its power consumption decreases due to the reduced air resistance. This can be recorded by measuring the current and voltage.

[0014] During a cleaning cycle, the device continuously or at specific intervals checks the operating parameters of its blower or the sensor readings. If these (or at least one of them) deviate from standard values ​​and exceed a defined threshold, or if they reach values ​​within a determined tolerance indicating a blockage, the device initiates a procedure to attempt to clear the detected blockage.

[0015] First, the device switches off its fan to free any objects that have been sucked in. Simultaneously, it slowly rotates its brush roller backwards to prevent further objects from being drawn into the device and to push any trapped objects back out. During this process, the device preferably moves backwards from its current position (e.g., by 1 meter) to distance itself from any trapped objects or to pull them out of the device by moving backwards.

[0016] In an advantageous embodiment, before the current operating parameter of the suction fan or the current sensor measurement is subsequently determined, the fan is activated at its highest power level. The device then attempts to clear any blockage in the air ducts by abruptly drawing in the sucked-up objects, so that they land in the dustbin and no longer pose a significant obstacle to the airflow. To achieve this, the device activates its fan at its highest power level for a short period, for example, 5 seconds.

[0017] After attempting to dislodge the suctioned objects, the device now checks the success of its actions. To do this, it restarts its blower at the previously set power level and checks the operating parameters of the running blower or the sensor readings. If these are within the permissible range, the device can assume that the blockage has been successfully cleared. The device can then continue its cleaning cycle. The cleaning process will therefore continue if the current operating parameter of the suction blower falls below the predefined threshold or if the current sensor reading no longer indicates a blockage.

[0018] However, if the device detects that at least one operating parameter of the blower exceeds a threshold value again during its control attempt, it must be assumed that the blockage persists and that the device cannot clear it on its own. The device deactivates its blower and preferably returns to the starting point of its cleaning task, for example, to its charging station. In this case, the cleaning task is therefore aborted if the current operating parameter of the suction blower exceeds the predefined threshold value or if the current sensor reading still indicates a blockage.

[0019] In another advantageous embodiment, a message regarding the blockage is displayed to the device user. If the blockage has been successfully cleared, the user can also be notified (e.g., via app and / or push notification) that a blockage event occurred but was resolved, and optionally, where this blockage event took place. The user is free to decide whether or not to view the possible causes of the blockage. If the blockage has not been successfully cleared and therefore persists, the user receives a message (e.g., via app and / or push notification) indicating that a blockage event has occurred that the device cannot clear. The device will then, for example, not start any new cleaning tasks until the user has cleared the blockage and confirmed this on the device (via the user interface or app).Preferably, the device can continue to start cleaning jobs that do not involve the use of the blower (e.g., wet cleaning jobs for mopping the floor).

[0020] Should the user wish to send the device on new cleaning cycles before the blockage has been cleared, the device can remind him of the incident with a repeated message about the blockage and the necessary shutdown to protect the blower.

[0021] In a further advantageous embodiment, the operating parameter is the current, voltage, and / or speed of the suction blower. Preferably, several operating parameters of the suction blower are determined and each compared with a predetermined threshold value. Clearing the blockage is particularly preferred if at least one of the operating parameters exceeds its predetermined threshold value.

[0022] As an alternative to reading the blower parameters, the control system can access sensors to detect blockages or obstructions in the air ducts. Possible sensors include: pressure sensors that can detect abnormally strong negative pressure upstream of the blower; airflow sensors that can detect a significant reduction in airflow in the air ducts upstream or downstream of the blower; air velocity sensors that can detect a significant reduction in airflow velocity or a complete cessation of airflow upstream or downstream of the blower; and other (light) barriers, switches, or buttons that are triggered when an air duct becomes blocked. In addition to detecting blockages, the sensors used can also measure other parameters and be used for further analysis.

[0023] The invention further relates to a mobile, self-propelled device equipped to carry out a method as described. It is understood that, in addition to the method and the device, a computer program product comprising commands that, upon execution of the program, cause a device to perform the method according to the invention is also included in the scope of this invention. Likewise, a computer-readable medium on which such a computer program product is stored is included in the scope of this invention.

[0024] Any features, designs, embodiments and advantages relating to the method also apply in connection with the device according to the invention, computer program product and computer-readable medium, and vice versa.

[0025] The invention is explained in more detail with reference to the following examples. These examples show: Figure 1A, 1B: each a schematic view of an embodiment of a mobile, self-driving device provided for the method according to the invention, Figure 2 : a schematic view of an embodiment of a mobile, self-driving device intended for the method according to the invention, Figure 3 : a flowchart of an exemplary embodiment of a method according to the invention.

[0026] In Figure 1A is a mobile, self-driving device, in particular a robot 10 shown in overhead view. Figure 1B shows robot 10 of the Figure 1A in a bottom view. The robot 10 includes a suction nozzle 1 in which a brush roller 2 is integrated, as well as a suction blower (not in Figure 1A, 1B(shown). Furthermore, the robot 10 has a side brush 3 with side brush arms at a front lateral position on its housing. The side brush 3 is designed to transport dust and dirt, especially along walls and in corners, to the suction opening 1 of the robot vacuum.

[0027] The robot 10 is also equipped with navigation sensors that can perceive its surroundings. For example, the robot has a LIDAR sensor 4 on its housing, a camera 12, and / or a wall-following sensor. The robot 10's control system can interpret the sensor data from the LIDAR sensor 4 to determine, among other things, which room or type of room the robot 10 is currently in. The robot 10 can infer the type of room from the furnishings and furniture.

[0028] In addition to its dry cleaning unit (brush roller 2, suction blower, side brush 3), the robot 10 has a wet cleaning module (water tank, pump, cleaning pad 5, optional actuator for cleaning pad movement).

[0029] In Figure 2 Is the robot 10 of the Figure 1AThe simplified representation shows the robot 10 cleaning robot. A controller 6 is located within the robot 10. This controller is responsible for evaluating sensor data, planning cleaning missions, determining the cleaning routes, and controlling the actuators. A drive 7 enables the robot 10 to move in a controlled manner. The robot 10's suction fan 8 is located downstream of a dust box 9 containing a filter 11. Air, including entrained dust particles, is drawn in by the suction fan 8 and enters the robot 10 through the suction nozzle 1. It is then guided through air ducts to the dust box 9, the filter 11, and subsequently cleaned before returning to the suction fan 8 and exiting the robot 10. The controller 6 within the robot 10 can control the suction fan 8 and read and process its current parameters, such as current, voltage, and rotational speed. At the end of a cleaning cycle or in the event of a malfunction, the controller 6 can deactivate the suction fan 8.

[0030] During a cleaning run, the robot 10 continuously or at specific intervals checks the operating parameters of its suction blower 8. If these, in particular at least one of them, deviate from standard values ​​and exceed a defined threshold or assume values ​​that are within a determined tolerance indicating a blockage, the robot 10 begins a procedure in which it attempts to resolve the detected blockage.

[0031] In particular, the robot 10 detects a blockage in at least one of its air ducts by evaluating its blower parameters, attempts to clear it autonomously, independently deactivates the blower 8, and optionally informs a user. This proactive action by the robot 10 prevents permanent damage to the suction blower 8 and the robot 10 itself. Ideally, the robot 10 can resolve the situation independently without user intervention. The autonomous method for detecting and clearing a blockage by the robot is described in Figure 3 depicted.

[0032] In step 101, the cleaning robot performs a cleaning run. During this run, the robot continuously monitors the operating parameters of its blower (step 102) or monitors them at specific intervals. If any of the operating parameters exceed a threshold, the robot registers a blockage (step 103). In step 104, the robot attempts to clear the blockage autonomously. First, the robot switches off its blower to free any objects that may have been sucked in. Simultaneously, it slowly rotates its brush roller backward to prevent further objects from being drawn into the robot and to push any trapped objects back out. While doing this, the robot preferably moves backward from its current position (e.g., by 1 meter) to distance itself from any trapped objects or to allow the robot to pull them out by moving backward.

[0033] After completing the first phase, the robot then attempts to clear any blockage in the air ducts by abruptly pulling in any vacuumed objects so that they land in the dustbin and no longer obstruct the airflow (step 105). To do this, the robot activates its fan at full power for a short time (e.g., 5 seconds).

[0034] After completing the second phase, the cleaning robot now checks the success of the actions performed. To do this, it restarts its fan at the previously set power level and checks the operating parameters of the running fan (step 106).

[0035] If these values ​​are now back within the permissible range, i.e., below the predetermined thresholds, the robot can assume that the blockage has been successfully cleared. The robot can then resume its interrupted cleaning cycle (step 108a). Additionally, the user is notified (e.g., via app and / or push notification) that a blockage event occurred (and preferably where it took place), but that it has been resolved (step 107a). The user is then free to decide whether or not to investigate what might have caused the blockage.

[0036] However, if the robot detects that at least one operating parameter of the blower exceeds a threshold again during its check attempt, it must be assumed that the blockage persists and that the robot cannot clear it on its own (step 107b). The robot deactivates its blower and returns to the starting point of its cleaning task (e.g., its charging station) (step 108b). The user receives a message (e.g., via app and / or push notification) that there is a blockage event that the robot cannot clear (step 109). The robot will not start any new cleaning tasks, especially using the blower, until the user has cleared the blockage and confirmed this to the robot (via UI, via app) (step 110).Should the user wish to send the robot on new cleaning runs before the blockage has been cleared, the robot can remind them of the incident with a repeated message about the blockage and the necessary shutdown to protect the blower.

[0037] As an alternative to reading the operating parameters of the blower, the control system can access existing sensors to detect a blockage or obstruction of the airflow and adjust the procedure accordingly. Figure 3to be carried out. Possible sensors include pressure sensors that can detect a strong negative pressure in front of the blower; airflow sensors that can detect a significant reduction in airflow in the air ducts before or after the blower; air velocity sensors that can detect a significant reduction in airflow velocity or a complete stoppage of airflow before or after the blower; and / or other (light) barriers, switches, or buttons that are triggered when an air duct becomes blocked.

Claims

1. Method for detecting and clearing a blockage in an air duct of a mobile, self-propelled device comprising a suction blower (8) and a brush roller (2) and performing a cleaning task, comprising the following method steps: - Determining at least one operating parameter of the suction blower (8) or a sensor measurement value, - Comparing the operating parameter with a predetermined threshold value or evaluating the sensor measurement value, - Switching off the suction blower (8) if the operating parameter exceeds the predetermined threshold value or the sensor measurement value indicates the blockage, - Rotating the brush roller (2) backwards, - Reversing the device, and - Switching on the suction blower (8) and subsequently determining the current operating parameter of the suction blower (8) or the current sensor measurement value.

2. Method according to claim 1, wherein the suction blower (8) is activated at the highest power level before the subsequent determination of the current operating parameter of the suction blower (8) or the current sensor measurement value.

3. Method according to one of the preceding claims, wherein the cleaning order is continued if the current operating parameter of the suction blower (8) falls below the predetermined threshold or the current sensor measurement no longer indicates a blockage.

4. Method according to one of the preceding claims, wherein the cleaning order is aborted if the current operating parameter of the suction blower (8) exceeds the predetermined threshold value or the current sensor measurement continues to indicate a blockage.

5. Method according to one of the preceding claims, wherein a message concerning the blockage is displayed to a user of the device.

6. Method according to one of the preceding claims, wherein the operating parameter is the current, the voltage and / or the speed of the suction blower (8).

7. Method according to one of the preceding claims, wherein several operating parameters of the suction blower (8) are determined and each is compared with a predetermined threshold value.

8. Method according to claim 7, wherein the clearing of the blockage is carried out if at least one of the operating parameters exceeds its predetermined threshold.

9. Method according to one of the preceding claims, wherein the sensor is a pressure sensor, an air flow sensor, an air velocity sensor, a (light) barrier, a switch or a push button.

10. Mobile, self-driving device configured to perform a method according to any of the preceding claims.

11. Computer program product comprising instructions which, when the program is executed by the device, cause it to execute the method according to any one of the preceding claims 1 to 9.

12. Computer-readable data carrier on which the computer program product according to claim 11 is stored.

Images