ROBOTIC VACUUM CLEANING

• US 20090133720A1
• Filed: 01/31/2007
• Published: 05/28/2009
• Est. Priority Date: 02/13/2006
• Status: Active Grant

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: VAN DEN BOGERT, Willem Frederik
• Granted Patent: US 9,510,715 B2
• Time in Patent Office: Days
• US Class Current: 134/18
• CPC Class Codes: A47L 2201/04 Automatic control of the travelling movement; Automatic obstacle detection
• CPC Class Codes: A47L 5/362 of the horizontal type, e.g. canister or sledge type
• CPC Class Codes: A47L 9/04 with driven brushes or agitators
• CPC Class Codes: G05D 1/0225 involving docking at a fixed facility, e.g. base station or loading bay parking aids B62D15/027
• CPC Class Codes: G05D 1/024 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0242 using non-visible light signals, e.g. IR or UV signals
• CPC Class Codes: G05D 1/0246 using a video camera in combination with image processing means
• CPC Class Codes: G05D 1/0255 using acoustic signals, e.g. ultra-sonic singals sonar systems designed for anti-collision purposes G01S15/93
• CPC Class Codes: G05D 1/0257 using a radar radar systems designed for anti-collision purposes between land vehicles or between land vehicle and fixed obstacles G01S13/931
• CPC Class Codes: G05D 1/0274 using mapping information stored in a memory device navigation using map-matching G01C21/30

Abstract

A robotic vacuum cleaner has a control system arranged for controlling at least frequency or intensity of contact between a cleaning brush of its suction nozzle (3) and each brushable portion of a floor surface (20) to be cleaned, such that, at least for some brushable portions of floor surface (20) closely adjacent to at least one of the boundaries (18) of the vacuum cleanable floor surface, at least the frequency or the intensity of contact between the cleaning brush and each of the floor surface portions decreases with a decrease of the distance to the at least one boundary of the vacuum cleanable floor surface (20). A method for robotic vacuum cleaning is also described. With the vacuum cleaner and the method of robotic vacuum cleaning according to the present invention the negative influence of vacuum cleaning on the durability of the visual attractiveness of a floor cover or a carpet is reduced.

Claims

1. A robotic vacuum cleaner comprising:

a suction nozzle (3) with a cleaning brush (9) arranged for contacting a floor surface (20, 21);

a drive and steering mechanism (10, 11, 12, 13) for providing mobility and steerability to at least the suction nozzle (3);

at least one detector (14, 15, 16, 17) for determining boundaries (18, 19) of a vacuum cleanable floor surface (20, 21); and

a control system (28) communicating with the at least one detector (14, 15, 16, 17), and with the drive mechanism (10, 11, 12, 13) for conducting the suction nozzle (3) over the vacuum cleanable floor surface (20, 21),

characterized in that the control system is arranged for controlling at least frequency or intensity of contact between the cleaning brush (9) and each portion of the floor surface (20, 21) to be brushed, such that, at least for some portions of floor surface closely adjacent to at least one of the boundaries (18, 19) of the vacuum cleanable floor surface (20, 21), at least the frequency or the intensity of contact between the cleaning brush (9) and each of the floor surface portions decreases with a decrease of the distance to the at least one boundary (18, 19) of the vacuum cleanable floor surface (20, 21).

2. A vacuum cleaner according to claim 1, wherein the control system (28) is arranged for automatically reducing the intensity of contact between the cleaning brush (9) and the floor surface in response to a distance to the at least one boundary (18, 19) of the vacuum cleanable floor surface (20, 21) below at least one predetermined value.

3. A vacuum cleaner according to claim 2, wherein the cleaning brush (9) is drivable for motion within the suction nozzle (3) and wherein the control system (28) is arranged for controlling the velocity of rotation of the cleaning brush (9) for reducing the velocity of rotation in response to a distance to the at least one boundary (18, 19) of the vacuum cleanable floor surface (20, 21) below at least one predetermined value.

4. A vacuum cleaner according to claim 3, wherein the control system (28) is arranged for controlling a motor for ceasing driving of the cleaning brush (9) in response to a distance to the at least one boundary (18, 19) of the vacuum cleanable floor surface (20, 21) below at least one predetermined value.

5. A vacuum cleaner according to claim 2, wherein the cleaning brush (9) is suspended for contacting the floor surface (20, 21) with a controllable downward contact force and wherein the control system (28) is arranged for causing the downward force to be reduced in response to a distance to the at least one boundary (18, 19) of the vacuum cleanable floor surface (20, 21) below at least one predetermined value.

6. A vacuum cleaner according to claim 1, wherein the suction nozzle (3) has a footprint with a footprint contour and wherein the cleaning brush (9) is shaped and suspended for brushing in a brushing area having a brushing area contour, the brushing area contour being located within and spaced from the footprint contour.

7. A vacuum cleaner according to claim 1, wherein the control system (28) is arranged for gradually reducing the intensity of contact between the cleaning brush (9) and the floor surface (20, 21) in response to a change of the distance to the at least one boundary (18, 19) of the vacuum cleanable floor surface (20, 21).

8. A vacuum cleaner according to claim 1, further comprising a floor type sensor connected with the controller for determining the type of surface that is being cleaned and wherein the control system is arranged for the controlling of at least the frequency or the intensity of contact between the cleaning brush (9) and the floor surface, such that at least, at least for portions of floor surface closely adjacent to at least one of the boundaries of the vacuum cleanable floor surface (20, 21), the frequency or the intensity of contact between the cleaning brush (9) and the floor surface decreases with the distance to the at least one boundary of the vacuum cleanable floor surface (20, 21), only in response to a signal from the floor type sensor indicating a predetermined type of floor surface or one of a predetermined group of floor types.

9. A vacuum cleaner according to claim 8, wherein the at least one detector (16, 17) for determining boundaries (18, 19) of a vacuum cleanable floor surface (20, 21) also is the floor type sensor.

10. A vacuum cleaner according to claim 1, wherein the at least one detector (16, 17) for determining boundaries (18, 19) of a vacuum cleanable floor surface (20, 21) is a vision system.

11. A vacuum cleaner according to claim 1, wherein the control system (28) includes a memory for storing a map of the vacuum cleanable floor surface (20, 21) and trajectories followed by the suction nozzle (3), the control system (28) being arranged for conducting the suction nozzle (12) such that:

during each cleaning cycle, the suction nozzle (12) is moved along a plurality of successive suction nozzle trajectories (26, 27) covering a surface (20, 21) to be cleaned;

a first minimum distance is maintained between the at least one boundary (18, 19) and the suction nozzle (3) during a first cleaning cycle, and

a second minimum distance different from said first minimum distance is maintained between the at least one boundary (18, 19) and the suction nozzle (3) during a second cleaning cycle.

12. A method for robotic vacuum cleaning a floor surface (20, 21), comprising:

passing a suction nozzle (3) with a cleaning brush (9) contacting the floor surface (20, 21) over the floor surface (20, 21) to be cleaned, under control of a control system (28) communicating with at least one detector (14, 15, 16, 17) for determining at least one boundary (18, 19) of the floor surface (20, 21) to be cleaned,

characterized in that the control system controls at least frequency or intensity of contact between the cleaning brush (9) and each portion of the floor surface (20, 21) being brushed, such that, at least for some portions of floor surface closely adjacent to at least one of the boundaries (18, 19) of the vacuum cleanable floor surface (20, 21), at least the frequency or the intensity of contact between the cleaning brush (9) and each of the floor surface portions decreases with a decrease of the distance to the at least one boundary (18, 19) of the vacuum cleanable floor surface (20, 21).