Floor treatment by means of an autonomous mobile robot

1 . A method for controlling an autonomous mobile robot, comprising the following:

controlling the robot in a treatment mode for treating a floor surface with a floor treatment module of the robot;

detecting a dirt sensor signal representing the level of soiling of the floor surface by means of a dirt sensor arranged on the robot; and

modifying a speed of the robot during the treatment of the floor surface based on the dirt sensor signal,

wherein the robot, in the treatment mode, moves over the floor surface at a speed which is less than or equal to a maximum speed associated with the treatment mode, and

wherein modifying the speed of the robot is achieved by reducing the maximum speed and a current speed of the robot is only reduced if the current speed of the robot is greater than the reduced maximum speed.

2 . The method according to claim 1 , wherein the dirt sensor signal can assume a first state and a second state depending on the level of soiling of the floor surface.

3 . The method according to claim 2 , wherein the first state of the dirt sensor signal indicates a normal level of soiling and the second state of the dirt sensor signal indicates a high level of soiling.

4 . The method according to claim 2 , wherein the treatment mode is associated with a maximum speed of the robot, and

wherein the maximum speed depends on the state of the dirt sensor signal.

5 . The method according to claim 2 , wherein the speed of the robot is reduced from a first value to a second value in response to the second state of the dirt sensor signal.

6 . The method according to claim 5 , wherein the speed, after it has been reduced, is reset again to the first value according to at least one pre-definable criterion.

7 . The method according to claim 6 , wherein the at least one pre-definable criterion comprises at least one of the following: the dirt sensor signal resumes the first state; the dirt sensor signal resumes the first state and a pre-definable time has passed since then; the dirt sensor signal resumes the first state and the robot has moved a defined distance since then; a pre-definable time has passed since the reduction of the speed; the robot has moved a pre-definable distance since the reduction of the speed.

8 . The method according to claim 2 , wherein the robot stops in response to a change of the dirt sensor signal from the first to the second state.

9 . The method according to claim 8 , wherein the treatment mode is resumed in a normal direction of travel at reduced speed after a stop or reverse movement.

10 . The method according to claim 2 , wherein the robot moves in reverse in response to the change of the dirt sensor signal from the first to the second state.

11 . The method according to claim 10 , wherein the reverse movement is achieved by the fact that the robot moves backward in a straight line or along the most recently taken trajectory for a pre-definable distance and/or duration.

12 . The method according to claim 10 , wherein obstacles are taken into account during the reverse movement in such a manner that a collision is avoided.

13 . The method according to claim 10 , wherein the robot stores information regarding the location of obstacles in a map, and uses the information stored in the map to avoid collisions during reverse movements without using current sensor information regarding obstacles.

14 . The method according to claim 1 , wherein controlling the robot in a treatment mode comprises:

executing a path planning based on map information and the robot position according to a movement pattern associated with the treatment mode, an obstacle avoidance strategy associated with the treatment mode, and a strategy for re-treating previously untreated areas associated with the treatment mode; and

converting the planned path into drive commands.

15 . The method according to claim 1 , further comprising:

planning, by a navigation module of the robot, a path of the robot based on a stored map data.

16 . The method according to claim 15 , further comprising:

updating, by a control unit of the robot, a map of an application area of the robot during the operation of the robot by means of the navigation module.

17 . The method according to claim 15 , wherein the robot further comprises a control unit providing functions for navigating the robot in an application area, wherein the functions are provided by the navigation module.

18 . The method according to claim 1 , further comprising:

changing a direction of travel of the robot based on the dirt sensor signal.

19 . The method according to claim 18 , further comprising:

modifying a planned trajectory based on the dirt sensor signal.

20 . The method according to claim 18 , further comprising:

covering a floor area recognized as heavily soiled several times.

21 . The method according to claim 1 , wherein the speed, after it has been reduced, is reset again to its original value based on a pre-definable time or a pre-definable distance.

22 . The method according to claim 1 , wherein, when the dirt sensor indicates a high level of soiling, the robot backs up until the detected signal for the level of soiling is low or normal.