Autonomous floor-cleaning robot

• US 8,516,651 B2
• Filed: 12/17/2010
• Issued: 08/27/2013
• Est. Priority Date: 01/03/2002
• Status: Expired due to Term

• Current Assignee: iRobot Corporation
• Original Assignee: iRobot Corporation
• Inventors: Jones, Joseph L., Mack, Newton E., Nugent, David M., Sandin, Paul E.
• Primary Examiner(s): SCRUGGS, ROBERT J
• Application Number:
  US12/971,281
• Publication Number:
  US 20110131741A1
• Time in Patent Office: 984 Days
• Field of Search: 153/19, 153/39, 15/521, 153/401, 153/56, 153/60, 700/245
• US Class Current: 15/319
• CPC Class Codes: A47L 11/282 having rotary tools
• CPC Class Codes: A47L 11/4061 Steering means; Means for avoiding obstacles; Details related to the place where the driver is accommodated
• CPC Class Codes: A47L 11/4066 Propulsion of the whole machine
• CPC Class Codes: A47L 2201/00 Robotic cleaning machines, i.e. with automatic control of the travelling movement or the cleaning operation
• CPC Class Codes: A47L 2201/04 Automatic control of the travelling movement; Automatic obstacle detection
• CPC Class Codes: A47L 2201/06 Control of the cleaning action for autonomous devices; Automatic detection of the surface condition before, during or after cleaning
• CPC Class Codes: A47L 5/30 with driven dust-loosening tools, e.g. rotating brushes
• CPC Class Codes: A47L 5/34 with height adjustment of nozzles or dust-loosening tools
• CPC Class Codes: A47L 7/02 with driven tools for special purposes with floor-polishing tools A47L11/20
• CPC Class Codes: A47L 9/009 Carrying-vehicles; Arrangements of trollies or wheels; Means for avoiding mechanical obstacles
• CPC Class Codes: A47L 9/0411 driven by electric motor
• CPC Class Codes: A47L 9/0477 Rolls
• CPC Class Codes: A47L 9/0494 Height adjustment of dust-loosening tools
• CPC Class Codes: A47L 9/1409 Rigid filtering receptacles dust collecting receptacles for cyclones A47L9/1683
• CPC Class Codes: A47L 9/2826 the condition of the floor
• CPC Class Codes: A47L 9/2852 Elements for displacement of the vacuum cleaner or the accessories therefor, e.g. wheels, casters or nozzles
• CPC Class Codes: A47L 9/2894 Details related to signal transmission in suction cleaners
• CPC Class Codes: A47L 9/32 Handles

Abstract

An autonomous floor-cleaning robot comprising a housing infrastructure including a chassis, a power subsystem; for providing the energy to power the autonomous floor-cleaning robot, a motive subsystem operative to propel the autonomous floor-cleaning robot for cleaning operations, a command and control subsystem operative to control the autonomous floor-cleaning robot to effect cleaning operations, and a self-adjusting cleaning head subsystem that includes a deck mounted in pivotal combination with the chassis, a brush assembly mounted in combination with the deck and powered by the motive subsystem to sweep up particulates during cleaning operations, a vacuum assembly disposed in combination with the deck and powered by the motive subsystem to ingest particulates during cleaning operations, and a deck adjusting subassembly mounted in combination with the motive subsystem for the brush assembly, the deck, and the chassis that is automatically operative in response to an increase in brush torque in said brush assembly to pivot the deck with respect to said chassis. The autonomous floor-cleaning robot also includes a side brush assembly mounted in combination with the chassis and powered by the motive subsystem to entrain particulates outside the periphery of the housing infrastructure and to direct such particulates towards the self-adjusting cleaning head subsystem.

Claims

1. An autonomous floor-cleaning robot comprising:

first and second wheel assemblies configured to propel the robot along a cleaning surface;

a brush assembly comprising a motor and a brush, the motor arranged to rotate the brush as the first and second wheel assemblies propel the robot across the cleaning surface;

a plurality of control sensors operative to regulate the normal operation of the autonomous floor-cleaning robot, the plurality of control sensors comprising a proximity sensor, a prohibited area entry prevention sensor, and a wheel rotation sensor;

a plurality of emergency sensors operative to detect situations adverse to the normal operation of the autonomous floor-cleaning robot, the plurality of emergency sensors comprising a cliff detector array, a first and a second wheel drop sensor, and a stall sensor; and

a controller configured to control the first and second wheel assemblies based upon signals from the plurality of control sensors and the plurality of emergency sensors, wherein the first and second wheel assemblies each comprise a wheel and a tension spring, each tension spring biasing pivotal movement of a respective wheel through an arc to a position in which an axis of rotation of each respective wheel lies below a bottom plane of the autonomous floor-cleaning robot, and the first and second wheel drop sensors each comprise a contact switch configured to transmit a signal to the controller when an axis of rotation of a wheel of each respective wheel assembly lies below the bottom plane of the autonomous floor-cleaning robot.

2. The autonomous floor-cleaning robot of claim 1, wherein the controller comprises a preprogrammed movement pattern of the robot and the controller is further configured to initiate the preprogrammed movement pattern based upon signals from the plurality of control sensors and the plurality of emergency sensors.

3. The autonomous floor-cleaning robot of claim 1, wherein the proximity sensor is configured to detect proximity of a wall.

4. The autonomous floor-cleaning robot of claim 3, wherein the controller is configured to direct the robot in a wall following mode.

5. The autonomous floor-cleaning robot of claim 1, wherein the stall sensor is configured to detect a change in current of the motor and transmit a signal indicative of the change in current to the controller.

6. The autonomous floor-cleaning robot of claim 5, wherein the brush is rotatable about an axis parallel to the cleaning surface.

7. The autonomous floor-cleaning robot of claim 5, wherein the brush is rotatable about an axis substantially perpendicular to the cleaning surface.

8. The autonomous floor-cleaning robot of claim 5, wherein the brush extends beyond a periphery of the housing as the robot moves along the cleaning surface.

9. The autonomous floor-cleaning robot of claim 8, wherein the brush is adjacent to the cliff detector and the brush comprises opposed brush arms of constant width.

10. The autonomous floor-cleaning robot of claim 1, further comprising a displaceable bumper movable upon contact with an object.

11. The autonomous floor-cleaning robot of claim 10, wherein at least one of the following is mounted on the displaceable bumper:

the proximity sensor, the cliff detector, and the prohibited area entry prevention sensor.

12. The autonomous floor-cleaning robot of claim 11, wherein the cliff detector is disposed along a lower portion of the displaceable bumper and the cliff detector is configured to detect a predetermined drop in the path of the robot as the robot travels across the cleaning surface.

13. The autonomous floor-cleaning robot of claim 10, wherein the prohibited area entry prevention sensor is disposed on top of the displaceable bumper, along an axis bisecting the displaceable bumper.

14. The autonomous floor-cleaning robot of claim 1, wherein the prohibited area entry prevention sensor is configured to detect the presence of a stand-alone emitter.

15. The autonomous floor-cleaning robot of claim 14, wherein the prohibited area entry prevention sensor is configured to detect a force field and a collimated beam emitted by the stand alone emitter.

16. The autonomous floor-cleaning robot of claim 14, wherein the controller is configured to prevent the robot from entering an area based at least in part on the detected presence of the stand-alone emitter by the prohibited area entry prevention sensor.

17. The autonomous floor-cleaning robot of claim 1, wherein the wheel rotation sensor is configured to measure the rotation of an associated wheel subassembly.