COORDINATED TRANSPORT ROBOT SYSTEM

• US 20150142249A1
• Filed: 10/24/2014
• Published: 05/21/2015
• Est. Priority Date: 11/20/2013
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: OGAWA, Hideki, OOGA, Junichiro
• Granted Patent: US 9,315,367 B2
• Time in Patent Office: Days
• US Class Current: 701/23
• CPC Class Codes: B66F 9/063 Automatically guided
• CPC Class Codes: B66F 9/07577 not supported by wheels, e.g. tracks or air cushions
• CPC Class Codes: Y10S 901/01 Mobile robot

Abstract

A coordinated transport robot system according to an embodiment includes: first and second robots each including a mobile unit and a movement control unit; first and second position error absorption mechanisms provided on the first and second robots; an impedance model estimating an external force from the amount of displacement detected by the passive element unit; an external force estimating unit estimating respective external forces acting on the first and second robots based on external forces estimated with a dynamics model and estimated by the impedance model; a compliance model calculating respective position correction amounts of the first and second robots to make an external force zero; and a movement command calculating unit calculating movement commands to the first and second robots based on the position correction amounts. Each of the movement control units control the respective mobile units based on the respective movement commands.

Claims

1. A coordinated transport robot system, comprising:

first and second robots each including a mobile unit and a movement control unit configured to control the mobile unit;

first and second position error absorption mechanisms provided on the first and second robots, respectively, each of the first and second position error absorption mechanisms including a top panel onto which a transport object to be placed and fixed, a passive element unit configured to rotationally move the top panel in a horizontal direction and detect an amount of displacement of rotational movement, and an active element unit configured to translationally move the top panel in the horizontal direction and detect an amount of displacement of translational movement;

an impedance model configured to estimate an external force from the amount of displacement detected by the passive element unit;

an external force estimating unit configured to estimate respective external forces acting on the first and second robots based on an external force estimated with a dynamics model based on the amount of displacement detected by the active element unit, and an external force estimated by the impedance model;

a compliance model configured to calculate respective position correction amounts of the first and second robots to make an external force zero, the external force being estimated by the external force estimating unit; and

a movement command calculating unit configured to calculate movement commands to the first and second robots based on the position correction amounts calculated by the compliance model;

wherein the movement control units of the first and second robots control the respective mobile units based on the respective movement commands calculated by the movement command calculating unit.

2. The system according to claim 1, further comprising:

a mutual sensing unit measuring a distance and a direction between the first and second robots;

an odometry calculating unit estimating and calculating a self-location based on values of integrals of movement control amounts of the first and second robots and position information from the mobile control units; and

a mutual distance evaluating unit estimating a mutual distance between the first and second robots based on the self-location calculated by the odometry calculating unit and the distance and the direction between the first and second robots calculated by the mutual sensing unit,

wherein the movement command calculating unit calculates the movement commands to the first and second robots based on the position correction amounts and the mutual distance estimated by the mutual distance evaluating unit.

3. The system according to claim 1, further comprising:

a movement control responsiveness model configured to approximate responsiveness from the movement commands and actual movement amounts of the first and second robots,

wherein the movement command calculating unit corrects the movement commands by using the predicted values of movement amounts calculated by the movement control responsiveness model.

4. The system according to claim 1, wherein

the movement control responsiveness model is a self-movement control responsiveness model of the first and second robots, and

the self-movement control responsiveness model is obtained by measuring a response signal generated when the transport object is placed on the robot system and a movement command value for identification is given to one of the first and second robots.

5. The system according to claim 1, wherein,

the movement control responsiveness model is an other'"'"'s movement control responsiveness model of the other robot as opposed to one robot of the first and second robots, and

the other'"'"'s movement control responsiveness model is obtained from time-series data of a movement command value for the other robot and a self-location of the one robot.

6. The system according to claim 1, wherein each of the position error absorption mechanisms includes:

a first member provided below the top panel;

a first rotation mechanism enabling the first member to rotate with respect to the top panel about a center of the top panel;

a second member provided below the first member;

a third member provided below the second member;

a first translational movement mechanism causing the first member to translationally move with respect to the second member in a first direction in the horizontal direction;

a second translational movement mechanism causing the third member to translationally move with respect to the second member in a second direction perpendicular to the first direction in the horizontal direction;

a fourth member fixed to the third member;

a first pair of gonio-stages causing the fourth member to rotate in an arc about a first rotational axis located thereabove, the first pair of gonio-stages being engaged with the fourth member and facing each other;

a fifth member fixed to the first pair of gonio-stages; and

a second pair of gonio-stages causing the fifth member to rotate in an arc about a second rotational axis that is provided thereabove and intersects the first rotational axis at one point, the second pair of gonio-stages being provided on the robot having the position error absorption mechanism, the second pair of gonio-stages being engaged with the fifth member and facing each other in a direction perpendicular to a direction in which the first pair of gonio-stages are arranged.