Autonomous robot auto-docking and energy management systems and methods

• US 8,749,196 B2
• Filed: 12/29/2006
• Issued: 06/10/2014
• Est. Priority Date: 01/21/2004
• Status: Active Grant

• Current Assignee: iRobot Corporation
• Original Assignee: iRobot Corporation
• Inventors: Cohen, David A., Ozick, Daniel, Vu, Clara, Lynch, James, Mass, Philip R.
• Primary Examiner(s): Williams, Arun
• Assistant Examiner(s): PIGGUSH, AARON C
• Application Number:
  US11/648,230
• Publication Number:
  US 20080007203A1
• Time in Patent Office: 2,720 Days
• Field of Search: 320/109, 700/262, 901/46
• US Class Current: 320/109
• CPC Class Codes: A47L 2201/02 Docking stations; Docking operations
• CPC Class Codes: A47L 2201/022 Recharging of batteries
• CPC Class Codes: A47L 2201/04 Automatic control of the travelling movement; Automatic obstacle detection
• CPC Class Codes: A47L 9/0063 External storing devices; Stands, casings or the like for the storage of suction cleaners
• CPC Class Codes: A47L 9/009 Carrying-vehicles; Arrangements of trollies or wheels; Means for avoiding mechanical obstacles
• CPC Class Codes: A47L 9/2805 Parameters or conditions being sensed
• 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 9/2873 Docking units or charging stations for autonomous or robotic vacuum cleaners A47L2201/02
• 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: B25J 11/0085 Cleaning
• CPC Class Codes: B25J 19/005 using batteries, e.g. as a back-up power source
• CPC Class Codes: B25J 5/00 Manipulators mounted on wheels or on carriages B25J1/00 takes precedence; programme-controlled manipulators B25J9/00 ; vehicle aspects B60, B62, e.g. remote-controlled steering for motor vehicles B62D1/24; control of position of vehicles G05D1/00
• CPC Class Codes: B25J 9/1664 characterised by motion, path, trajectory planning
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• CPC Class Codes: G01S 1/16 Azimuthal guidance systems, e.g. system for defining aircraft approach path, localiser system
• CPC Class Codes: G01S 1/7034 Mounting or deployment thereof
• CPC Class Codes: G01S 1/7038 Signal details
• CPC Class Codes: G01S 2201/01 adapted for specific applications or environments
• CPC Class Codes: G05D 1/0219 : ensuring the processing of the whole working surface
• 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 1/0227 : using mechanical sensing means, e.g. for sensing treated area
• CPC Class Codes: G05D 1/0242 : using non-visible light signals, e.g. IR or UV signals
• CPC Class Codes: H02J 7/00 : Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/00309 : Overheat or overtemperature protection
• CPC Class Codes: H02J 7/0036 : using connection detecting circuits H02J7/0034 takes precedence
• CPC Class Codes: H02J 7/0044 : specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence
• CPC Class Codes: H02J 7/0045 : concerning the insertion or the connection of the batteries
• CPC Class Codes: H02J 7/00714 : in response to battery charging or discharging current
• CPC Class Codes: H02J 7/007182 : in response to battery voltage
• CPC Class Codes: H02J 7/04 : Regulation of charging current or voltage
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 : Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles
• CPC Class Codes: Y10S 901/01 : Mobile robot

Abstract

A method for energy management in a robotic device includes providing a base station for mating with the robotic device, determining a quantity of energy stored in an energy storage unit of the robotic device, and performing a predetermined task based at least in part on the quantity of energy stored. Also disclosed are systems for emitting avoidance signals to prevent inadvertent contact between the robot and the base station, and systems for emitting homing signals to allow the robotic device to accurately dock with the base station.

Claims

1. A method of docking a robotic device with a base station comprising a plurality of signal emitters including a right signal emitter and a left signal emitter, the method comprising the steps of:

detecting, by a sensor mounted to remain continuously fixed parallel to a fore-aft axis of the robotic device that is perpendicular to a differential drive wheels of the robotic device, (i) a right signal transmitted by the right signal emitter, (ii) a left signal transmitted by the left signal emitter, and (iii) an overlap zone between the right signal and the left signal that includes both the right signal and the left signal, wherein the left signal is encoded differently from the right signal;

determining when the robot is outside the overlap zone and, when the robot is outside of the overlap zone, orienting the fore-aft axis of the robotic device and the sensor in relation to the right signal and the left signal, wherein the fore-aft axis is moved towards the right if the left signal is detected and the right signal is not detected and the fore-aft axis is moved towards to the left if the right signal is detected and the left signal is not detected;

determining when the robot is inside the overlap zone and, when the robot is inside of the overlap zone, maintaining an orientation of the fore-aft axis of the robotic device and the sensor as the robotic device approaches to the base station by following a path defined at least in part by the overlap zone.

2. The method of claim 1 further comprising the step of:

docking the robotic device with the base station.

3. The method of claim 1 wherein the step of following the path defined at least in part by the zone comprises reducing velocity of the robotic device.

4. The method of claim 2 wherein the step of docking the robotic device with the base station comprises:

detecting, by the robotic device, contact with charging terminals on the base station; and

stopping movement of the robotic device.

5. The method of claim 4 further comprising the step of charging the robotic device.

6. The method of claim 5 wherein the step of charging the robotic device comprises providing a plurality of current charging levels.

7. The method of claim 6, further comprising detecting the presence of the robotic device at the charging terminals of the base station using a first non-charging, sensing current level and providing a second charging current level across the charging terminals upon detecting the presence of the robotic device at the charging terminals.

8. The method of claim 1, further comprising detecting an energy level of a battery of the robotic device and seeking, by the robotic device, the right and left signals when the energy level of the battery is less than a first predetermined energy level.

9. The method of claim 8, further comprising ceasing, by the robotic device, a predetermined task upon detecting that the energy level of the battery is below a second predetermined energy level that is lower than the first predetermined energy level.

10. The method of claim 9, further comprising resuming, by the robotic device, the predetermined task upon completion of charging of the battery.

11. The method of claim 9, further comprising altering a travel characteristic of the robotic device in seeking the left and right signals.

12. The method of claim 1, further comprising alternately moving the robotic device towards the right to position the left signal to the left relative to the robotic device, and towards the left to position the right signal to the right relative to the robotic device.

13. The method of claim 1, further comprising moving the robotic device towards the base station in reference to the zone.

14. The method of claim 1, wherein recognizing a left signal different than the right signal comprises recognizing at least one of a color of a signal, a carrier frequency of a signal, a modulation of a signal, a bit pattern of a signal and a wavelength of a signal.

15. The method of claim 1, further comprising avoiding, by the robotic device, the left and right signals while an energy level of a battery of the robotic device remains above a first predetermined energy level.

16. The method of claim 1, wherein the sensor is an omnidirectional sensor.

17. The method of claim 1, wherein the wheel is supported on an undercarriage of the robotic device and the sensor is mounted in a fixed position relative to the undercarriage of the robotic device.

18. A method of docking a robotic device with a base station comprising a plurality of signal emitters including a right signal emitter and a left signal emitter, the method comprising the steps of:

recognizing, by the robotic device, a signal transmitted by the right signal emitter as a right signal;

recognizing, by the robotic device, a signal transmitted by the left signal emitter as a left signal, encoded differently than the right signal;

turning the robotic device to keep the left signal on the left of the robotic device and to keep the right signal on the right of the robotic device;

detecting, by a sensor mounted to remain continuously fixed parallel to a fore-aft axis of the robotic device that is perpendicular to a differential drive wheels of the robotic device, an overlap zone between the right signal and the left signal that includes both the right signal and the left signal;

when the robot is outside of the overlap zone, orienting the fore-aft axis of the robotic device and the sensor in relation to the right signal transmitted by the right signal emitter and the left signal transmitted by the left signal emitter wherein the fore-aft axis is moved towards the right if the left signal is detected and the right signal is not detected and the fore-aft axis is moved towards to the left if the right signal is detected and the left signal is not detected;

determining when the robot is inside the overlap zone and when the robot is inside of the overlap zone, maintaining an orientation the fore-aft axis of the robotic device and the sensor as the robotic device approaches to the base station by following a path defined at least in part by the overlap zone.

19. The method of claim 18 further comprising the steps of:

docking the robotic device with the base station.

20. The method of claim 18, further comprising detecting the presence of the robotic device at the charging terminals of the base station using a first non-charging, sensing current level and providing a second charging current level across the charging terminals upon detecting the presence of the robotic device at the charging terminals.

21. The method of claim 18, further comprising detecting an energy level of a battery of the robotic device and seeking, by the robotic device, the right and left signals when the energy level of the battery is less than a first predetermined energy level.

22. The method of claim 21, further comprising ceasing, by the robotic device, a predetermined task upon detecting that the energy level of the battery is below a second predetermined energy level that is lower than the first predetermined energy level.

23. The method of claim 18, further comprising alternately moving the robotic device towards the right to position the left signal to the left relative to the robotic device, and towards the left to position the right signal to the right relative to the robotic device.

24. The method of claim 18, wherein recognizing a left signal different than the right signal comprises recognizing at least one of a color of a signal, a carrier frequency of a signal, a modulation of a signal, a bit pattern of a signal and a wavelength of a signal.