Celestial navigation system for an autonomous robot

• US 8,594,840 B1
• Filed: 03/31/2009
• Issued: 11/26/2013
• Est. Priority Date: 07/07/2004
• Status: Active Grant

• Current Assignee: iRobot Corporation
• Original Assignee: iRobot Corporation
• Inventors: Chiappetta, Mark J., Frankel, James Paul
• Primary Examiner(s): Amin, Bhavesh V
• Application Number:
  US12/415,554
• Time in Patent Office: 1,701 Days
• Field of Search: None
• US Class Current: 700/245
• 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 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 9/2826 the condition of the floor
• CPC Class Codes: A47L 9/2836 characterised by the parts which are controlled
• CPC Class Codes: A47L 9/2894 Details related to signal transmission in suction cleaners
• CPC Class Codes: B60L 53/38 specially adapted for charging by inductive energy transfer
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01C 21/206 specially adapted for indoor navigation
• CPC Class Codes: G01S 5/0284 Relative positioning
• CPC Class Codes: G05D 1/0016 characterised by the operator's input device input arrangements for computing systems in general G06F3/00
• CPC Class Codes: G05D 1/0088 characterized by the autonomous decision making process, e.g. artificial intelligence, predefined behaviours using knowledge based models G06N5/00
• 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 1/0234 using optical markers or beacons optical beacons per se G01S1/70
• 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 1/0246 using a video camera in combination with image processing means
• CPC Class Codes: G05D 1/0274 using mapping information stored in a memory device navigation using map-matching G01C21/30
• CPC Class Codes: G05D 1/0276 : using signals provided by a source external to the vehicle involving a plurality of vehicles G05D1/0287; automatically controlling vehicle speed responsive to externally generated signals B60K31/0058
• CPC Class Codes: G06F 17/00 : Digital computing or data processing equipment or methods, specially adapted for specific functions information retrieval, database structures or file system structures therefor G06F16/00
• CPC Class Codes: H02J 2310/14 : The load or loads being home appliances
• CPC Class Codes: H02J 50/001 : Energy harvesting or scavenging
• CPC Class Codes: H02J 50/10 : using inductive coupling
• CPC Class Codes: H02J 50/12 : of the resonant type
• CPC Class Codes: H02J 50/20 : using microwaves or radio frequency waves
• CPC Class Codes: H02J 50/90 : involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H04W 88/06 : adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• 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: Y10S 901/01 : Mobile robot

Abstract

An autonomous robot system including a transmitter disposed within a working area and a mobile robot operating within the working area. The transmitter includes an emitter for emitting at least one signal onto a remote surface above the working area. The mobile robot includes a robot body, a drive system configured to maneuver the robot over a surface within the working area, and a navigation system in communication with the drive system. The navigation system includes a receiver responsive to the emitted signal as reflected off of the remote surface and a processor connected to the receiver and configured to determine a relative location of the robot within the working area in response to the receiver responding to the reflected signal.

Claims

1. An autonomous robot system comprising:

a transmitter disposed within a working area and comprising first and second emitters for emitting respective first and second signals onto a ceiling above the working area; and

a mobile robot moving within the working area relative to the transmitter, the mobile robot comprising;

a robot body;

a drive system disposed on the robot body and configured to maneuver the robot over a surface within the working area; and

a navigation system in communication with the drive system, the navigation system comprising;

a receiver responsive to reflections of the first and second emitted signals from the ceiling; and

a processor connected to the receiver and configured to determine a relative location of the robot within the working area in response to the receiver responding to the reflections of the first and second emitted signals;

wherein the first and second emitted signals are directable onto the ceiling.

2. The autonomous robot system of claim 1, wherein the first and second emitted signals are directed toward the ceiling at an angle of about 30 degrees with respect to each other.

3. The autonomous robot system of claim 1, wherein the transmitter further comprises a collimator for focusing and directing the emitted signals.

4. The autonomous robot system of claim 1, wherein the first and second emitted signals each comprise a coded signal having a code as a unique identifier, the processor configured to identify the coded signal from the respective code.

5. The autonomous robot system of claim 4, wherein each emitted signal is modulated at about 10 kHz.

6. The autonomous robot system of claim 4, wherein the transmitter pulses the coded emitted signals according to a transmission cycle, the transmission cycle comprising:

emitting the first coded signal and then stopping emission of the first coded signal;

delaying transmission;

emitting the second coded signal and then stopping emission of the second coded signal;

and then delaying transmission.

7. The autonomous robot system of claim 6, wherein the transmission cycle further comprises emitting a synchronization signal prior to emitting the first coded signal.

8. The autonomous robot system of claim 6, wherein the transmission cycle further comprises emitting an end signal after emission of each coded signal and preceding each transmission delay.

9. The autonomous robot system of claim 1, wherein the receiver comprises a plurality of discrete photodiodes arranged angularly spaced adjacent to one another and substantially in a plane.

10. The autonomous robot system of claim 1, wherein the navigation system is configured to maneuver the robot according to a heading, and when only one of the emitted signals is detected by the receiver, the navigation system altering the heading to substantially coincide with detected signal at least until the other signal is detected by the receiver.

11. The autonomous robot system of claim 1, wherein when only one of the emitted signals is detected by the receiver, the navigation system is configured to maneuver the robot about the working area until the other signal is detected by the receiver.

12. The autonomous robot system of claim 1, wherein the receiver is configured to measure an amount of infrared energy present in a space about the robot and set a threshold energy value, and any subsequent energy measurements by the receiver above the threshold energy value triggering an event in the navigation system.

13. The autonomous robot system of claim 1, wherein the processor is configured to determine an azimuth angle of each received signal based at least in part on a ratio of signal amplitude values, wherein the signal amplitude values used in determining the azimuth angle comprises the two strongest signal amplitude values among the photodiodes.

14. The autonomous robot system of claim 1, wherein the processor is configured to determine an azimuth angle and elevation of the first and second signals on the ceiling based on the received reflected signals, the processor determining a location of the robot within the working area based on the azimuth angle and elevation of the respective first and second signals.

15. The autonomous robot system of claim 1, wherein the processor is configured to store the azimuth angle and elevation of the respective first and second signals in memory and produce a map of the working area based on the stored azimuth angle and elevation of the respective first and second signals.

16. The autonomous robot system of claim 1, further comprising:

an obstacle sensor in communication with the navigation system and responsive to obstacles adjacent the robot, the navigation system configured to maneuver the robot based at least in part on an obstacle detection signal received from the obstacle sensor and indicating presence of an adjacent obstacle.

17. The autonomous robot system of claim 16, wherein the obstacle sensor comprises a bump sensor.

18. The autonomous robot system of claim 16, wherein the processor is configured to produce a map of working area based at least in part on an obstacle detection signal received from the obstacle sensor, the navigation system configured to maneuver the robot about the working area with the aid of the map to avoid mapped obstacles.

19. The autonomous robot system of claim 18, wherein the processor is configured to create a map of the working area based on the relative locations of the robot as the robot maneuvers about the working area.

20. The autonomous robot system of claim 16, wherein the robot further comprises:

a floor cleaner disposed on the robot body; and

a dirt sensor in communication with the navigation system, the navigation system maneuvering the robot at least in part in response to a signal from the dirt sensor, wherein the navigation system is configured to associate dirt location information within the working area with a received dirt sensor signal, the navigation system maneuvering the robot at least in part in response to the dirt location information.