Autonomous mobile robot system

• US 9,192,869 B2
• Filed: 06/04/2009
• Issued: 11/24/2015
• Est. Priority Date: 06/09/2008
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Moriya, Toshio
• Primary Examiner(s): Edwards, Jerrah
• Application Number:
  US12/478,400
• Publication Number:
  US 20090326713A1
• Time in Patent Office: 2,364 Days
• Field of Search: 701/2, 701/25, 701/301, 901/1, 901/46
• US Class Current: 1/1
• CPC Class Codes: A63H 17/00 Toy vehicles, e.g. with self-drive; convertible into other toys A63H33/003; Cranes, winches or the like; Accessories therefor traffic games with figures moved by players A63F9/14
• CPC Class Codes: A63H 2200/00 Computerized interactive toys, e.g. dolls
• CPC Class Codes: B25J 9/1676 Avoiding collision or forbidden zones
• CPC Class Codes: G05B 2219/39085 Use of two dimensional maps and feedback of external and joint sensors
• CPC Class Codes: G05D 1/0214 in accordance with safety or protection criteria, e.g. avoiding hazardous areas monitoring the location of vehicles within a certain area, e.g. forbidden or allowed areas, in traffic control systems for road vehicles G08G1/13
• 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 1/0274 using mapping information stored in a memory device navigation using map-matching G01C21/30

Abstract

The possibilities of collision of a mobile robot with objects can be reduced significantly in actual robot movements. In an aspect of the present invention, there is provided an autonomous mobile robot system including a mobile robot and a computing system. The mobile robot includes: a sensing section for measuring surrounding conditions of the mobile robot; a position-posture estimating section for estimating position-posture data from sensing data obtained by the sensing section and an environmental map; and a robot moving section for controlling movements of the mobile robot according to movement control data determined from the position-posture data thus estimated and movement route data.

Claims

1. A method of using an autonomous mobile robot system, the autonomous mobile robot system comprising:

a mobile robot; and

a computing system; and

the method comprising;

measuring, using the mobile robot, surrounding conditions of the mobile robot;

estimating, using the mobile robot, position-posture data from the measured surrounding conditions of the mobile robot and an environmental map;

controlling, using the mobile robot, movements of the mobile robot according to movement control data determined from the position-posture data estimated and movement route data;

generating, using the computer system, the environmental map indicating environmental geometric conditions including objects present in an environment where the mobile robot is to move around;

creating, using the computer system, the movement route data for movements of the mobile robot in a coordinate scheme of the environmental map; and

determining, using the computer system, a value of a collision probability parameter indicating a level of predictive probability of collision of the mobile robot with an object in mobile robot movements with inclusion of control errors through calculation by using robot composition information regarding the mobile robot, the environmental map prepared, and the movement route data created.

2. The method of claim 1, further comprising:

stimulating, using the computer system, movements of the mobile robot with inclusion of control errors by using a virtual mobile robot corresponding to the mobile robot, the virtual mobile robot being virtually defined in the computing system; and

determining, using the computer system, a value of a collision probability parameter indicating a level of predictive probability of collision of the virtual mobile robot with an object in virtual mobile robot movements determined by using the robot composition information, the environmental map, and the movement route data.

3. The method of claim 2, further comprising:

calculating, using the computer system, control data of the virtual mobile robot from an estimated position-posture value indicating an estimated position-posture state on the environmental map, in combination with the movement route data, and the robot composition information;

calculating, using the computer system, a value of a position-posture parameter of the virtual mobile robot from the control data calculated by the movement control data calculating simulator in combination with the robot composition information; and

calculating, using the computer system, a value of the collision probability parameter of the virtual mobile robot from a value of the position-posture parameter calculated by the robot movement simulator, in combination with the environmental map, and the robot composition information.

4. The method claim 3, further comprising:

calculating, using the computer system, virtual sensor data representing virtual definitions of the virtual mobile robot from a value of the position-posture parameter calculated, the environmental map, and the robot composition information; and

outputting, using the computer system, an estimated position-posture value by using the virtual sensor data and the environmental map.

5. The method of claim 3, further comprising:

calculating, using the computer system, a value of the collision probability parameter of the virtual mobile robot by using configuration information of the mobile robot contained in the robot composition information and configuration information of each object contained in the environmental map.

6. The method of claim 5, wherein the configuration information of each object contains information regarding a protruded/indented part along the height direction of the object.

7. The method of claim 3, further comprising:

providing, using the computer system, an estimated position-posture value based on a value of the position-posture parameter calculated.

8. The method claim 3, wherein the computing system further comprises a user interface configured to allow an operator to conduct interactive processing;

and the method further comprises;

allowing the operator to interactively set up a movement route to be taken by the mobile robot on the environmental map through the user interface.

9. The method claim 8, further comprising:

indicating, using the computer system, a path line included in a movement route of the virtual mobile robot on the environmental map according to the movement route data in a fashion such that the path line has at least one particular drawing attribute selected from a plurality of different drawing attributes including colors, thicknesses and line types in accordance with a value of the collision probability parameter calculated for the virtual mobile robot.

10. The method of claim 8, further comprising:

when two points are specified on the environmental map by the operator through the user interface, forming a path connecting the two specified points so that the mobile robot keeps a certain safe distance from objects, and the path formed is used as data for a movement route to be taken by the mobile robot.

11. The method of claim 10, further comprising:

when there are a plurality of candidate paths connecting the two specified points, presenting a candidate path having a collision probability parameter value indicating a relatively low level of predictive probability of collision as data for a movement route to be taken by the mobile robot.

12. The method of claim 3, wherein there is provided a small-type mobile robot that has a smaller size than that of the mobile robot and includes functional features of the computing system;

and the method further comprises;

measuring, using the small-type mobile robot, surrounding conditions of the small-type mobile robot;

estimating, using the small-type mobile robot, a position-posture value of the small-type mobile robot from measured surrounding conditions of the small-type mobile robot and the environmental map; and

controlling, using the small-type mobile robot, movements of the small-type mobile robot according to movement control data determined from the estimated position-posture value and movement route data.

13. The method of claim 12, further comprising:

moving the small-type mobile robot prior to movements of the mobile robot.

14. A method of using an autonomous mobile robot system,

the autonomous mobile robot system comprising:

a mobile robot including a sensing section configured to measure surrounding conditions of the mobile robot, a position-posture estimating section configured to estimate a position and a posture of the mobile robot from sensing data obtained by the sensing section and an environmental map, and a robot moving section configured to control movements of the mobile robot according to movement control data determined from the estimated position and posture of the robot and movement route data; and

a computing system including an environmental map generating section configured to generate the environmental map indicating environmental geometric conditions of an environment, in which the mobile robot is to move around and at least an obstacle exists;

the method comprising steps of;

creating, using the computer system, the movement route data for movements of the mobile robot in a coordinate scheme of the environmental map;

simulating, using the computer system, the estimation performed in the position-posture estimating section by inputting virtual sensor data which includes sensing errors obtained on the basis of random number selection in error probability distribution modeling;

simulating, using the computer system, the control performed in the robot moving section by inputting the result of simulation of the estimation to derive a result of a virtual control of the mobile robot in a form of probability distribution indicating a certain range of extent; and

determining, using the computer system, a value of a collision probability parameter indicating a level of predictive probability of collision of the mobile robot with the obstacle from the result of the virtual control of the mobile robot.

15. The method of claim 14, wherein the step of simulating the control performed in the robot moving section includes steps of:

calculating virtual control data of the mobile robot from the result of simulation of the estimation and the environmental map; and

calculating the result of virtual control of the mobile robot on the basis of the calculated virtual control data of the mobile robot.

16. The method of claim 15, wherein the step of calculating the result of virtual control of the mobile robot includes deriving parameters regarding a position and a posture to be taken by the mobile robot as the result of the virtual control of the mobile robot according to an error probability model which is formed through pre-experiment using the mobile robot.

17. The method of claim 14, further comprising:

calculating, using the computer system, a value of the collision probability parameter of the mobile robot by using configuration information of the mobile robot contained in a robot composition information and configuration information of each object contained in the environmental map.

18. The method of claim 17, wherein the configuration information of each object contains information regarding a protruded/indented part along the height direction of the object.

19. The method of claim 14, further comprising:

providing, using the computer system, an estimated position-posture value based on a value of a position-posture parameter calculated.

20. The method claim 16, wherein the computing system further comprises a user interface configured to allow an operator to conduct interactive processing;

and the method further comprises;

allowing the operator to interactively set up a movement route to be taken by the mobile robot on the environmental map through the user interface.

21. The method claim 20, further comprising:

indicating, using the computer system, a path line included in a movement route of a virtual mobile robot on the environmental map according to movement route data in a fashion such that the path line has at least one particular drawing attribute selected from a plurality of different drawing attributes including colors, thicknesses and line types in accordance with a value of the collision probability parameter calculated for the virtual mobile robot.

22. The method of claim 20, further comprising:

when two points are specified on the environmental map by the operator through the user interface, forming a path connecting the two specified points so that the mobile robot keeps a certain safe distance from objects, and the path formed is used as data for a movement route to be taken by the mobile robot.

23. The method of claim 22, further comprising:

when there are a plurality of candidate paths connecting the two specified points, presenting a candidate path having a collision probability parameter value indicating a relatively low level of predictive probability of collision as data for a movement route to be taken by the mobile robot.

24. The method of claim 14, wherein there is provided a small-type mobile robot that has a smaller size than that of the mobile robot and includes functional features of the computing system;

and the method further comprises;

measuring, using the small-type mobile robot, surrounding conditions of the small-type mobile robot;

estimating, using the small-type mobile robot, a position-posture value of the small-type mobile robot from measured surrounding conditions of the small-type mobile robot and the environmental map; and

controlling, using the small-type mobile robot, movements of the small-type mobile robot according to movement control data determined from the estimated position-posture value and movement route data.

25. The method of claim 24, further comprising:

moving the small-type mobile robot prior to movements of the mobile robot.