Wall following robot

Patent metadata

Field	Value
Publication number	US-2016299503-A1
Application number	US-201514946500-A
Country	US
Kind code	A1
Filing date	Nov 19, 2015
Priority date	Apr 9, 2015
Publication date	Oct 13, 2016
Grant date	—

Abstract

An example robot includes a body that is movable relative to a surface, a bumper mounted on the body to enable movement of the bumper relative to the body, a sensor to produce a signal in response to the movement of the bumper relative to the body caused by contact between the bumper and the surface, and a controller to control movement of the body to cause the body to track the surface based on a value. The bumper is movable between an uncompressed position relative to the body and a compressed position relative to the body. The signal varies linearly with the movement of the bumper relative to the body. The value is based on the signal and indicates that the bumper in a partially compressed position has a compression range between the uncompressed position and the compressed position.

First claim

What is claimed is:

1 - 30 . (canceled)

31 . A mobile cleaning robot comprising:
a body that is movable relative to a wall surface; a cleaning pad attached to a bottom of the body; a reservoir within the body configured to hold a fluid; a spraying mechanism configured to dispense the fluid from the robot; a bumper mounted on the body to enable movement of the bumper relative to the body, the bumper being movable relative to the body within a range defined by an uncompressed position of the bumper and a compressed position of the bumper; a controller to execute instructions to perform operations comprising:
controlling movement of the body to cause the body to track the wall surface to maintain an angle of between about 3 degrees and about 20 degrees between the body and the wall surface; and
maintaining contact between the cleaning pad and the wall surface while tracking the wall surface.

32 . The mobile cleaning robot of claim 31 , wherein:
the body comprises a left side and a right side, and the operations further comprise controlling the movement of the body to cause the body to track the wall surface so that at least one of the right side and the left side of the body is non-parallel to the wall surface.

33 . The mobile cleaning robot of claim 31 , wherein controlling movement of the body comprises adjusting rotational and translational speeds of the robot to cause the body to:
contact the wall surface at the angle such that the bumper is in a partially compressed position within the range defined by the compressed position and the uncompressed position; and maintain compression of the bumper in the partially compressed position.

34 . The mobile cleaning robot of claim 31 , wherein:
the robot further comprises a sensor to produce a signal in response to the movement of the bumper relative to the body caused by contact between the bumper and the wall surface, the signal varying linearly with the movement of the bumper relative to the body; and the operations further comprise causing the body to track the wall surface based at least in part on a value indicative of an amount of compression of the bumper, the value being based on the signal and indicating that the bumper in a partially compressed position within the range defined by the uncompressed position and the compressed position.

35 . The mobile cleaning robot of claim 34 , wherein the sensor comprises:
a post mounted to the bumper; a magnet mounted to the post; and a Hall effect sensor mounted in the body above the magnet.

36 . The mobile cleaning robot of claim 34 , wherein the sensor comprises a capacitive sensor, the capacitive sensor comprising a first capacitive plate in a fixed location relative to the bumper and a second capacitive plate in a fixed location relative to the body, the first capacitive plate being movable relative to the second capacitive plate based on the movement of the bumper.

37 . The mobile cleaning robot of claim 34 , wherein the sensor comprises an inductive sensor.

38 . The mobile cleaning robot of claim 34 , wherein the sensor is a first sensor and the signal is a first signal, and wherein the robot further comprises:
a second sensor to produce a second signal in response to the movement of the bumper, the second signal varying linearly with the movement of the bumper; wherein the operations further comprise calculating the value based on a first value that is based on the first signal and a second value that is based on the second signal.

39 . The mobile cleaning robot of claim 38 , wherein the body comprises a left side, a right side, a front, and a back;
wherein the first sensor is adjacent to the right side and the second sensor is adjacent to the left side; and wherein the bumper is located along the front of the robot and extends partially along the left side and the right side.

40 . The mobile cleaning robot of claim 34 , wherein the operations further comprise controlling the movement of the body to cause the body to retreat from the wall surface in response to the value being outside a compression range and indicative of the bumper being compressed further than an amount of compression associated with the compression range.

41 . The mobile cleaning robot of claim 34 , wherein the operations further comprise controlling the movement of the body to cause the body to turn toward the wall surface in response to the value being outside a compression range and indicative of the bumper being compressed less than an amount of compression associated with the compression range.

42 . The mobile cleaning robot of claim 34 , wherein the body comprises wheels;
wherein the robot further comprises detectors associated with the wheels, the detectors for detecting speed of the wheels; and wherein the operations comprise controlling the movement of the body to cause the body to retreat from the wall surface, to turn-away from the wall surface, and then to re-engage the surface based, at least in part, on the speed of the wheels being less than a predetermined speed and the value being outside a compression range.

43 . The mobile cleaning robot of claim 34 , wherein the operations further comprise dynamically calibrating the value to a neutral position of the bumper relative to the body in response to the bumper being within a predefined range of the uncompressed position.

44 . The mobile cleaning robot of claim 43 , wherein the operations further comprise controlling movement of the body to cause the body to move about a floor surface such that the bumper is not in contact with the wall surface; and
wherein dynamically calibrating the value to the neutral position of the bumper comprises determining the neutral position of the bumper relative to the body while the body moves around the floor surface.

45 . The mobile cleaning robot of claim 31 , wherein the body comprises a left side, a right side, a front, and a back, the bumper being located along the front of the body and extending at least partially along the left side and the right side; and
wherein the robot further comprises:
a first sensor adjacent to the right side to produce a first signal in response to the movement of the bumper;
a second sensor adjacent to the left side to produce a second signal in response to the movement of the bumper; and
a third sensor to produce a third signal in response to movement of the bumper, the third signal varying linearly with the movement of the bumper;
wherein the third sensor is between the left side and the right side, and the third sensor is adjacent to the front.

46 . The mobile cleaning robot of claim 45 , wherein the operations further comprise:
detecting movement of the bumper relative to the body along a first axis perpendicular to the front of the body based on the first and the second signals, and detecting movement of the bumper relative to the body along a second axis parallel to the front of the body based on the third signal.

47 . The mobile cleaning robot of claim 46 , wherein the first and second sensors are positioned to be responsive to the movement of the bumper relative to the body along the first axis, and the third sensor is positioned to be responsive to the movement of the bumper relative to the body along the second axis.

48 . The mobile cleaning robot of claim 31 , wherein the cleaning pad extends beyond a width of the bumper.

49 . The mobile cleaning robot of claim 31 , wherein:
maintaining contact between the cleaning pad and t

Assignees

• Irobot Corp

Inventors

• Wolfe Brian
• Lu Ping-Hong

Classifications

• A47L9/00

  Details or accessories of suction cleaners, e.g. mechanical means for controlling the suction or for effecting pulsating action; Storing devices specially adapted to suction cleaners or parts thereof; Carrying-vehicles specially adapted for suction cleaners · CPC title

• A47L2201/00

  Robotic cleaning machines, i.e. with automatic control of the travelling movement or the cleaning operation · CPC title

• Y10S901/01

  Mobile robot · CPC title

• A47L11/28

  Floor-scrubbing machines, motor-driven (A47L11/29 takes precedence) · CPC title

• A47L2201/04

  Automatic control of the travelling movement; Automatic obstacle detection · CPC title