Mobile robot and controller for same

• US 8,180,486 B2
• Filed: 09/28/2007
• Issued: 05/15/2012
• Est. Priority Date: 10/02/2006
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Saito, Yoko, Kawabe, Koji
• Primary Examiner(s): Tran, Khoi
• Assistant Examiner(s): MOYER, DALE S
• Application Number:
  US11/905,344
• Publication Number:
  US 20080086236A1
• Time in Patent Office: 1,691 Days
• Field of Search: 700245-264, 901/1
• US Class Current: 700/245
• CPC Class Codes: G01S 5/02524 Creating or updating the radio-map
• CPC Class Codes: G05D 1/0251 extracting 3D information from a plurality of images taken from different locations, e.g. stereo vision stereoscopic image analysis H04N13/00; depth recovery from images G06T7/593
• CPC Class Codes: G05D 1/028 using a RF signal
• CPC Class Codes: G06N 3/008 based on physical entities controlled by simulated intelligence so as to replicate intelligent life forms, e.g. based on robots replicating pets or humans in their appearance or behaviour

Abstract

A mobile robot includes a radio communication unit; a radio environment detector detecting plural types of radio environment data indicating the degree of goodness of radio environment, a comprehensive radio environment data being calculated from results of weighting the plural types of radio environment data with predetermined weights; a self-position detecting unit; a storage for map data of a movement area; the calculated comprehensive radio environment data being written in association with its own position detected. The robot moves at a movement speed not higher than the maximum movement speed determined so that communication with the radio base station is not cut off during movement and, if radio communication is cut off, searches the radio environment map for a communication restoration position where the radio communication is feasible to establish and moves to the communication restoration position and has the radio intensity reporting control section reporting the determined level of radio intensity.

Claims

1. A mobile robot which communicates by radio with a managing computer via one or more radio base stations coupled to the managing computer and autonomously moves in a movement area through use of map data of the movement area, comprising:

a radio communication unit for communicating by radio with each of the radio base stations;

a radio environment detecting unit for detecting plural types of radio environment data including radio intensity of a signal received by the radio communication unit in radio communication with the radio base station, wherein the radio environment data indicate degrees of goodness of a radio environment of the radio communication;

a comprehensive radio environment data calculating unit for weighting the plural types of radio environment data with predetermined weights and calculating comprehensive radio environment data from results of weighting, wherein the predetermined weights comprise intensity of radio wave and communication speed;

a self-position detecting unit for detecting a position of the robot in the movement area;

a storing unit for storing the map data of the movement area; and

a comprehensive radio environment map creating unit for creating a comprehensive radio environment map for each of the radio base stations by writing the calculated comprehensive radio environment data into the map data stored in the storing unit, the calculated comprehensive radio environment data associated with the position detected by the self-position detecting unit when the radio environment data was detected by the radio environment detecting unit.

2. The mobile robot according to claim 1, wherein the plural types of radio environment data include data about at least one of communication speed, the number of communication error times, and the number of data retransmission times in addition to the data about the radio intensity.

3. The mobile robot according to claim 1, further comprising a movement control unit for autonomously moving to a predetermined position based on the map data stored in the storing unit and the position detected by the self-position detecting unit and a detecting unit for at the predetermined position, detecting the plural types of radio environment data by the radio environment detecting unit.

4. The mobile robot according to claim 1, further comprising:

a movement detecting unit for detecting a movement direction and movement speed of a person,

wherein the mobile robot moves together with the person in the movement direction and at the movement speed detected by the movement detecting unit and detects the plural types of radio environment data on a path on which the mobile robot moves together with the person by the radio environment detecting unit.

5. The mobile robot according to claim 1, wherein the radio environment detecting unit detects the plural types of radio environment data repeatedly at predetermined timings, and the comprehensive radio environment data calculating unit calculates the comprehensive radio environment data based on the radio environment data obtained in each repetition of the detection, the mobile robot further comprising:

a comprehensive radio environment map updating unit for updating the comprehensive radio environment map by comparing the calculated comprehensive radio environment data as first data and the comprehensive radio environment data which is stored in the map data as second data in association with the position detected when the corresponding radio environment data was detected and, if a difference between the first and second data being at or above a predetermined value has occurred a predetermined number of consecutive times, replacing the comprehensive radio environment data stored in the map data with the last calculated comprehensive radio environment data.

6. The mobile robot according to claim 1, further comprising:

an image pickup unit; and

a surroundings image acquiring unit for acquiring and storing images of surroundings of the robot picked up by the image pickup unit at the position where the radio environment data was detected by the radio environment detecting unit in association with the position where the radio environment data was detected into the storing unit.

7. The mobile robot according to claim 1, further comprising:

an optimum radio base station map creating unit for creating an optimum radio base station map,

wherein the optimum radio base station map creating unit is configured to create the optimum radio base station map by writing, into the map data stored in the storing unit, the comprehensive radio environment data selected for each position, based on a plurality of comprehensive radio environment maps created by the comprehensive radio environment map creating unit respectively for the plurality of radio base stations, in association with the position.

8. The mobile robot according to claim 7, further comprising:

a radio base station failure notifying unit for determining whether the radio environmental data was normally detected as a failure and, when the radio environment data of one radio base station is not normally detected, notifying the occurrence of the failure in the one radio base station to the managing computer via a radio base station other than the one radio base station by the radio communication unit.

9. The mobile robot according to claim 1, further comprising a transmitting unit for transmitting a comprehensive radio environment map created by the comprehensive radio environment map creating unit to the managing computer via the radio communication unit.

10. The mobile robot according to claim 1, further comprising:

a movement controlling unit for driving and controlling a movement mechanism for the robot to move autonomously to a goal position specified by the managing computer using the comprehensive radio environmental map;

a movement speed instructing unit for instructing the movement controlling unit about a movement speed; and

a maximum movement speed determining unit for determining a maximum movement speed for a movement path decided by the position of the robot detected by the self-position detecting unit before starting to move and by the goal position based on the radio environment data and the maximum movement speed associated with the radio environment data beforehand,

wherein the movement speed instructing unit instructs the movement controlling unit about a movement speed not higher than the maximum movement speed determined by the maximum movement speed determining unit.

11. The mobile robot according to claim 10, wherein the radio environment data includes plural types of radio environment indexes including radio intensity of a signal received by the radio communication unit in radio communication with the radio base station, which indexes indicate the degrees of goodness of the radio environment of the radio communication.

12. The mobile robot according to claim 10, further comprising:

a radio base station selecting unit for selecting a radio base station for the radio communication unit to link to from the plurality of radio base stations based on the respective comprehensive radio environment maps for the radio base stations; and

a radio control switching unit for switching a link destination of the radio communication unit to the radio base station selected by the radio base station selecting unit,

wherein the maximum movement speed determining unit determines a maximum movement speed based on the radio environment data stored in the comprehensive radio environment map for the radio base station selected by the radio base station selecting unit.

13. The mobile robot according to claim 12, further comprising an optimum radio base station map creating unit for creating an optimum radio base station map by writing a radio base station having best comprehensive radio environment data selected for each of positions based on a plurality of comprehensive radio environment maps created by the comprehensive radio environment map creating unit respectively for the plurality of radio base stations, in association with the position into the map data stored in the storing unit, wherein the radio base station selecting unit selects a radio base station for the radio communication unit to link to from the radio base stations based on the optimum radio base station map.

14. The mobile robot according to claim 12, wherein when the radio control switching unit switches the link of the radio communication unit between the radio base stations, the movement speed instructing unit stops the robot moving.

15. The mobile robot according to claim 12, wherein the radio base station selecting unit selects a radio base station closest to the goal position from radio base stations with which radio communication is established at a current position before starting to move and for which the radio environment data for the goal position is at or above a predetermined value.

16. The mobile robot according to claim 1, further comprising:

a movement controlling unit for driving and controlling a movement mechanism for the robot to move autonomously;

a monitoring unit for monitoring a state of the radio environment;

a searching unit for, when the radio environment state being monitored becomes a state of radio communication being cut off, searching for a communication restoration position where the radio communication is feasible to establish based on the comprehensive radio environment map; and

a self-position move instructing unit for instructing the movement controlling unit to control move from the position detected to the communication restoration position found by the searching unit.

17. The mobile robot according to claim 16, wherein the comprehensive radio environment map further has position information of each of the radio base stations associated with the comprehensive radio environment data for each of the radio base stations, and

wherein the searching unit comprises:

a base station searching unit for searching for radio base stations within a predetermined distance of the position based on the comprehensive radio environment map; and

a communication restoration position searching unit for selecting one of the radio base stations found by the base station searching unit in the order of from the closest to the position and searching for a position for which the comprehensive radio environment data for the selected radio base station satisfies a predetermined reference condition and which is closest to the position to take the found position as the communication restoration position.

18. The mobile robot according to claim 16, wherein the movement controlling unit controls a drive structure including the movement mechanism to control the operation of the robot, further comprising:

an antenna move instructing unit for instructing the movement controlling unit to perform a predetermined operation so as to change the position or direction of an antenna that transmits and receives radio waves when the searching unit determines a failure in finding the communication restoration position.

19. The mobile robot according to claim 16, further comprising:

a movement history storing unit for storing a movement history indicating the movement path on which the mobile robot has moved; and

a move-back instructing unit for instructing the movement controlling unit to control to move back on the movement path by a predetermined amount of movement based on the movement history when the searching unit determines the failure in finding the communication restoration position.

20. The mobile robot according to claim 16, further comprising:

a movement stop instructing unit for instructing the movement controlling unit to control to stop moving at the position of the robot detected when the searching unit determines the failure in finding the communication restoration position.

21. The mobile robot according to claim 16, further comprising:

a decelerate instructing unit for instructing the movement controlling unit to decelerate the movement speed when the radio environment state being monitored by the monitoring unit is degraded below a predetermined reference.

22. The mobile robot according to claim 1, further comprising:

a radio intensity reporting control unit for determining at which one of a plurality of predetermined levels radio intensity at the position of the robot is in the movement area and reporting the determined level of radio intensity to the outside.

23. The mobile robot according to claim 22, wherein the radio intensity reporting control unit comprises an ear display provided in a part of the robot at an ear position of the robot and ear display control unit for controlling the ear display to light on the basis of the determined level of radio intensity.

24. The mobile robot according to claim 23, wherein the radio intensity reporting control unit determines the level of radio intensity based on a radio intensity map indicating information about radio intensity measured beforehand at each position in the movement area.

25. The mobile robot according to claim 23, wherein the radio intensity reporting control unit determines the level of radio intensity based on a current intensity of radio waves transmitted from the radio base station.

26. The mobile robot according to claim 23, wherein the radio intensity reporting control unit further comprises movement speed control unit for controlling and reducing the movement speed of the robot in accordance with the lighting state of the ear display when the level of radio intensity is determined to be at a predetermined low level during movement of the robot.

27. The mobile robot according to claim 26, wherein the radio intensity reporting control unit further comprises voice notifying control unit for, when reducing the movement speed by the movement speed control unit, notifying reduction in the movement speed by voice.

28. A controller for a mobile robot which communicates by radio with a managing computer via one or more radio base stations connected to the managing computer and autonomously moves in a movement area through use of map data of the movement area, the controller comprising:

a radio communication unit for communicating by radio with each of the radio base stations;

a radio environment detecting unit for detecting plural types of radio environment data including radio intensity of a signal received by the radio communication unit in radio communication with the radio base station, wherein the radio environment data indicate degrees of goodness of the radio environment of the radio communication;

a comprehensive radio environment data calculating unit for weighting the plural types of radio environment data with predetermined weights and calculating comprehensive radio environment data from results of weighting, wherein the predetermined weights comprise intensity of radio wave and communication speed;

a self-position detecting unit for detecting a position of the robot in the movement area;

a storing unit for storing the map data of the movement area; and

a comprehensive radio environment map creating unit for creating a comprehensive radio environment map for the radio base station by writing the calculated comprehensive radio environment data into the map data stored in the storing unit, the calculated comprehensive radio environment data associated with the position detected by the self-position detecting unit when the radio environment data was detected by the radio environment detecting unit.

29. The controller for the mobile robot according to claim 28, further comprising:

a movement controlling unit for driving and controlling a movement mechanism for the robot to move autonomously to a goal position specified by the managing computer using the comprehensive radio environment map;

a movement speed instructing unit for instructing the movement controlling unit about a movement speed; and

a maximum movement speed determining unit for determining a maximum movement speed for a movement path decided by the position of the robot detected by the self-position detecting unit before starting to move and by the goal position based on the radio environment data and the maximum movement speed associated with the radio environment data beforehand,

wherein the movement speed instructing unit instructs the movement controlling unit about a movement speed not higher than the maximum movement speed determined by the maximum movement speed determining unit.

30. The controller for the mobile robot according to claim 28, further comprising:

a radio environmental map storing unit for storing a comprehensive radio environment map for associating comprehensive radio environment data including a plurality of types of radio environmental data regarding the radio environment in the movement area with a map data in the movement area;

a movement controlling unit for driving and controlling a movement mechanism for the robot to move autonomously on the basis of a task transmitted from a base station using the comprehensive radio environment map;

a monitoring unit for monitoring the state of the radio environment;

a searching unit for, when the radio environment state being monitored becomes a state of radio communication being cut off, searching for a communication restoration position where the radio communication is feasible to establish based on the comprehensive radio environment map; and

a self-position move instructing unit for instructing the movement control unit to control to move from the position of the robot detected to the communication restoration position found by the searching unit.

31. The controller for the mobile robot according to claim 28, further comprising:

a radio intensity reporting control unit for determining at which one of a plurality of predetermined levels radio intensity at the position of the robot is in the movement area and reporting the determined level of radio intensity to the outside.