Moving robot

• US 20060243499A1
• Filed: 04/17/2006
• Published: 11/02/2006
• Est. Priority Date: 03/14/2005
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Hosoda, Yuji
• Granted Patent: US 7,677,345 B2
• Time in Patent Office: Days
• US Class Current: 180/8.500
• CPC Class Codes: B62D 57/024 specially adapted for moving on inclined or vertical surfaces endless-track vehicles for ascending or descending stairs B62D55/075; hand-carts with provision for travelling up or down stairs B62B5/02
• CPC Class Codes: B62D 57/028 having wheels and mechanical legs B62D57/024 takes precedence; ground-engaging vehicle fittings for supporting, lifting or manoeuvring the vehicle, wholly or in part B60S9/00

Abstract

Within a moving robot of narrow footprint, having quick traveling performance on a plane-surface, as well as, anti-tumbling function, and further being suitable for operations under coexistence with a human being, being able to travel coping with traveling situations on a level difference, etc.: in front and rear of main driving wheels 2 and 3, each being controlled through the inverted pendulum control, are disposed supporting legs 4 and 5, tips of which can be lifted up and down, wherein the tips of the supporting legs 4 and 5 are positioned to keep a predetermined distance between a traveling surface, when running on the inverted two-wheels travel, and the supporting legs 4 and 5 are fixed or either one in the fall-down direction is thrust out into the fall-down direction, so as to protect it from falling down. Further, upon the basis of detection information of floor-surface distance sensors 4e and 5e and side-surface distance sensor 4f, 4g, 5f and 5g, which are provided at the tips of the supporting legs 4 and 5, the robot senses an existence of a level difference and/or an inclined surface, so as to let the supporting legs to escape from the level difference and/or the inclined surface, and holds the position of gravity center thereof, stably, through other one of the supporting legs, being landed on the ground, and the main driving wheels 2 and 3; thereby enabling to travel over the level difference and the inclines surface.

Claims

1. A moving robot, comprising:

a moving mechanism of coaxial two-wheels type, having a pair of main driving wheels, for controlling driving force into a forward moving direction through an inverted pendulum control; and

a supporting leg, having at least one or more of an auxiliary wheel, wherein a relative position of said auxiliary wheel is changeable with respect to the main driving wheels of said moving mechanism.

2. The moving robot, as described in the claim 1, wherein said supporting legs are disposed in front and rear of the main driving wheels of said moving mechanism in the forward moving direction thereof, each being able to elevate the auxiliary wheel up and down with respect to a traveling surface.

3. The moving robot, as described in the claim 1, wherein said auxiliary wheel is a follower type wheel.

4. The moving robot, as described in the claim 2, wherein said auxiliary wheel is a follower type wheel.

5. The moving robot, as described in the claim 4, wherein said auxiliary wheel has a steering circling drive mechanism.

6. The moving robot, as described in the claim 1, wherein said supporting leg comprises a rotating mechanism of being able to move said auxiliary wheel, pivotally, into the driving direction with respect to said moving mechanism, and a thrusting mechanism of being able to control a distance from a rotation center of said rotating mechanism to said auxiliary wheel.

7. The moving robot, as described in the claim 6, wherein said auxiliary wheel is made of a follower type wheel, and further has a means for controlling a driving force into a forward moving direction through the inverted pendulum control, in a similar manner to that of said main driving wheels.

8. The moving robot, as described in the claim 7, wherein said auxiliary wheel has a steering circling drive mechanism.

9. The moving robot, as described in the claim 1, further comprising a means for measuring a relative distance between a tip of said supporting leg and a traveling surface, and a means for controlling positioning of said supporting leg so as to maintain it to be a predetermined relative distance.

10. The moving robot, as described in the claim 1, further comprising a means, brining said at least one supporting leg to be in contact on a driving surface on a ground, and for controlling a thrusting position of said supporting leg being in contact on the ground, so as to maintain a projection position of gravity within an area, which is defined through connecting a point of said supporting leg contacting on the ground and points of said main driving wheels contacting on the ground.

11. The moving robot, as described in the claim 9, wherein said supporting leg is fixed in position thereof, when an abnormality occurs within a control system, or when an electric power source is cut off, or when said moving robot is inclined in posture thereof, to be equal or greater than an allowable value thereof, under a condition of driving said main driving wheels upon basis of said inverted pendulum control.

12. The moving robot, as described in the claim 9, further comprising a control means for thrusting out said supporting leg in a fall-down direction of said moving robot, so as to recover said moving robot from the fall-down posture thereof, when an abnormality occurs within a control system, or when an electric power source is cut off, or when said moving robot is inclined in posture thereof, to be equal or greater than an allowable value thereof, under a condition of driving said main driving wheels upon basis of said inverted pendulum control.

13. The moving robot, as described in the claim 12, further comprising an emergency electric power source other than said electric power source, wherein driving control of said supporting leg is conducted for anti-tumbling thereof through said emergency electric power source.

14. The moving robot, as described in the claim 10, wherein assumption is made on an inclination angle of the traveling surface from an amount of thrusting said supporting leg to be in contact on the ground and a posture angle of said moving robot inclined, and determination is made that the traveling surface is a plane surface in case when the inclination angle of the traveling surface is less than a predetermined value, so as to initiate said inverted pendulum control on said main driving wheels.