Debris sensor for cleaning apparatus

• US 8,456,125 B2
• Filed: 12/15/2011
• Issued: 06/04/2013
• Est. Priority Date: 01/28/2004
• Status: Expired due to Term

• Current Assignee: iRobot Corporation
• Original Assignee: iRobot Corporation
• Inventors: Landry, Gregg W., Cohen, David A., Ozick, Daniel
• Primary Examiner(s): Ip, Paul
• Application Number:
  US13/326,997
• Publication Number:
  US 20120085368A1
• Time in Patent Office: 537 Days
• Field of Search: 318/587, 318/568.12, 700/23, 700/245, 700/259, 700/262, 700/253, 153/199.8, 153/19, 382/153
• US Class Current: 318/587
• CPC Class Codes: A47L 11/4005 Arrangements of batteries or cells; Electric power supply arrangements
• CPC Class Codes: A47L 11/4008 Arrangements of switches, indicators or the like
• CPC Class Codes: A47L 11/4011 Regulation of the cleaning machine by electric means; Control systems and remote control systems therefor
• 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 2201/04 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 5/362 of the horizontal type, e.g. canister or sledge type
• CPC Class Codes: A47L 9/0466 Rotating tools
• CPC Class Codes: A47L 9/0488 Combinations or arrangements of several tools, e.g. edge cleaning tools
• CPC Class Codes: A47L 9/2805 Parameters or conditions being sensed
• CPC Class Codes: A47L 9/281 the amount or condition of incoming dirt or dust
• CPC Class Codes: A47L 9/2831 Motor parameters, e.g. motor load or speed
• CPC Class Codes: A47L 9/2842 Suction motors or blowers
• 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 9/2857 User input or output elements for control, e.g. buttons, switches or displays
• CPC Class Codes: A47L 9/2884 Details of arrangements of batteries or their installation
• CPC Class Codes: A47L 9/2889 Safety or protection devices or systems, e.g. for prevention of motor over-heating or for protection of the user
• CPC Class Codes: A47L 9/2894 Details related to signal transmission in suction cleaners
• CPC Class Codes: G05D 1/021 specially adapted to land vehicles
• CPC Class Codes: G05D 1/0227 : using mechanical sensing means, e.g. for sensing treated area
• CPC Class Codes: G05D 1/0238 : using obstacle or wall sensors G05D1/0246 and G05D1/0289 take precedence; lidar systems designed for anti-collision purposes G01S17/93
• CPC Class Codes: G05D 1/0242 : using non-visible light signals, e.g. IR or UV signals
• CPC Class Codes: G05D 1/0272 : comprising means for registering the travel distance, e.g. revolutions of wheels measuring distance traversed on the ground by vehicles, e.g. using odometers G01C22/00
• CPC Class Codes: Y10S 901/01 : Mobile robot
• CPC Class Codes: Y10S 901/46 : Sensing device

Abstract

A piezoelectric debris sensor and associated signal processor responsive to debris strikes enable an autonomous or non-autonomous cleaning device to detect the presence of debris and in response, to select a behavioral mode, operational condition or pattern of movement, such as spot coverage or the like. Multiple sensor channels (e.g., left and right) can be used to enable the detection or generation of differential left/right debris signals and thereby enable an autonomous device to steer in the direction of debris.

Claims

1. An autonomous cleaning apparatus comprising:

a chassis;

a drive system disposed on the chassis and configured to move the cleaning apparatus over a cleaning surface;

a receptacle disposed on the chassis;

a cleaning head system disposed on the chassis and configured to move debris from the cleaning surface toward the receptacle;

a first and a second debris sensing element, each debris sensing element carried by the chassis and arranged to detect the debris moved toward the receptacle, each debris sensing element being within the chassis and proximate the other debris sensing element; and

a controller in communication with the drive system and the first and second debris sensing elements, the controller configured to steer the drive system immediately in a pattern of movement based at least in part on first and second signals received from the first and second debris sensing elements.

2. The autonomous cleaning apparatus of claim 1 wherein the chassis has a right side and a left side and the first debris sensing element is disposed on the right side of the chassis and the second debris sensing element is disposed on the left side of the chassis.

3. The autonomous cleaning apparatus of claim 2 wherein the controller is further configured to steer the drive system in the direction of the signal received from at least one of the first and second debris sensing elements.

4. The autonomous cleaning apparatus of claim 1 wherein the cleaning head system defines a cleaning width and at least one of the first and second debris sensing elements is sensitive to debris across the entire cleaning width.

5. The autonomous cleaning apparatus of claim 1 further comprising an electronic filter in electrical communication with the first debris sensing element, the electronic filter configured to attenuate at least a portion of the signal received from the first debris sensing element.

6. The autonomous cleaning apparatus of claim 1 wherein the first debris sensing element is spaced apart from the second debris sensing element and the controller is further configured to determine a debris gradient based at least in part on the first and second signals.

7. The autonomous cleaning apparatus of claim 6 wherein the controller is further configured to steer the drive system in the direction of debris based at least in part on the determined debris gradient.

8. The autonomous cleaning apparatus of claim 6 wherein the controller is further configured to adjust continuously the movement of the drive system based at least in part on the determined debris gradient.

9. The autonomous cleaning apparatus of claim 1 wherein the controller is further configured to select a pattern of movement of the drive system based at least in part on the signal received from the at least one of the first and second debris sensing elements.

10. The autonomous cleaning apparatus of claim 9 wherein the pattern of movement of the drive system comprises a spot coverage mode.

11. The autonomous cleaning apparatus of claim 10 wherein the spot coverage mode comprises movement of the drive system in a self-bounded area.

12. The autonomous cleaning apparatus of claim 1 wherein the receptacle is a removable dust cartridge and the cleaning head system comprises a brush arranged to direct debris to the removable dust cartridge.

13. The autonomous cleaning apparatus of claim 1 further comprising a user-perceptible signal in communication with the first and second debris sensing elements, wherein the user-perceptible signal is configured to alert a user to debris encountered by at least one of the first and second debris sensing elements.

14. The autonomous cleaning apparatus of claim 1 wherein each of the first and second debris sensing elements is configured to convert kinetic energy of a debris strike into electrical energy.

15. The autonomous cleaning apparatus of claim 14 wherein each of the first and second debris sensing elements comprises a piezoelectric transducer.

16. The autonomous cleaning apparatus of claim 1 wherein each of the first and second debris sensing elements is configured to generate an electrical pulse in response to being struck with debris.

17. A method of controlling an autonomous cleaning apparatus, the method comprising:

moving the autonomous cleaning apparatus over a cleaning surface;

receiving first and second signals from first and second debris sensing elements carried on the autonomous cleaning apparatus, the signals representative of the presence of debris on a cleaning surface, each of the first and second debris sensing elements being proximate the other; and

steering the autonomous cleaning apparatus immediately in a pattern of movement based at least in part on the received signals.

18. The method of claim 17 further comprising determining a debris gradient based at least in part on at least one of the first and second signals, wherein steering the autonomous cleaning apparatus immediately in a pattern of movement comprises steering the autonomous cleaning apparatus in the direction of the determined debris gradient.

19. The method of claim 18 further comprising continuously adjusting movement of the autonomous cleaning apparatus based at least in part on the determined debris gradient.

20. The method of claim 17 further comprising selecting a pattern of movement of the autonomous cleaning apparatus based at least in part on the received signals.

21. The method of claim 20 wherein selecting a pattern of movement of the autonomous cleaning apparatus comprises selecting a spot coverage mode.