Ball-balancing robot

Patent metadata

Field	Value
Publication number	US-10168715-B2
Application number	US-201715687588-A
Country	US
Kind code	B2
Filing date	Aug 28, 2017
Priority date	Mar 12, 2015
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

A ball-balancing robot is capable of accurately controlling its posture when a robot main body is rotated about the vertical axis in a yaw direction in a state in which the robot main body is positioned on a spherical object in a posture in which a gravity center of the robot main body matches a vertical axis passing a center of the spherical object, and in a state in which a base axis of the roll-direction angular velocity sensor is inclined with respect to the horizon in a pitch direction (at an inclination angle θp), the robot main body is able to rotate while maintaining a predetermined posture by making correction to cancel a detection error in the angular velocity in the roll direction generated based on the inclination of the base axis of the roll-direction angular velocity sensor.

First claim

What is claimed is:

1. A ball-balancing robot comprising:
a spherical object; and
a robot main body capable of rolling the spherical object in a state in which the robot main body is placed on the spherical object, and moving along with the spherical object; wherein
the robot main body includes:
a driver that rotates the robot main body on the spherical object in a yaw direction;
a yaw-direction angular velocity sensor that detects an angular velocity of the robot main body in the yaw direction; and
a roll-direction angular velocity sensor that detects an angular velocity of the robot main body in a roll direction; and
when the robot main body is rotated about a vertical axis in the yaw direction in a state in which the robot main body is located on the spherical object in a posture in which a gravity center of the robot main body matches a vertical axis passing a center of the spherical object, and in a state in which a base axis of the roll-direction angular velocity sensor is inclined with respect to a horizon in a pitch direction, the robot main body is able to be rotated about the vertical axis in the yaw direction while maintaining a predetermined posture by making correction to cancel a detection error in the angular velocity in the roll direction generated based on the inclination of the base axis of the roll-direction angular velocity sensor.

2. The ball-balancing robot according to claim 1 , wherein
the robot main body includes a pitch-direction angular velocity sensor that detects an angular velocity in the pitch direction; and
the robot main body obtains an angle of the inclination of the base axis of the roll-direction angular velocity sensor with respect to the horizon based on the angular velocity detected by the pitch-direction angular velocity sensor, and obtains an error in the angular velocity in the roll direction based on the obtained angle.

3. The ball-balancing robot according to claim 1 , wherein the robot main body is a spherical rigid body made of at least one of a resin and a metal.

4. The ball-balancing robot according to claim 1 , wherein the drive is a first driver and the ball-balancing robot includes a second driver and a third driver.

5. The ball-balancing robot according to claim 4 , wherein each of the first driver, the second driver and the third driver includes a wheel and a servomotor.

6. The ball-balancing robot according to claim 1 , wherein the driver includes a wheel and a servomotor.

7. The ball-balancing robot according to claim 1 , further comprising a controller the controls movement of the robot main body and includes a circuit board.

8. The ball-balancing robot according to claim 7 , wherein the pitch-direction angular velocity sensor and the roll-direction angular velocity sensor are mounted on the circuit board.

9. The ball-balancing robot according to claim 7 , wherein the circuit board is inclined with respect to the horizon in the pitch direction.

10. The ball-balancing robot according to claim 1 , wherein when an inclination angle of the base axis of the roll-direction angular velocity sensor with respect to the horizon is θ p , an angular velocity in the roll direction after the error is canceled is calculated according to ω r1 =(ω r −ω y ·sin θ p ), where ω r1 is an angular velocity in the roll direction after the error is canceled, ω r is an angular velocity in the roll direction before the error is canceled, ω y is an angular velocity in the yaw direction, and θ p is an inclination angle in the pitch direction.

11. The ball-balancing robot according to claim 10 , wherein an inclination of the robot main body in the roll direction when the robot main body is rotated in the yaw direction is calculated using the angular velocity ω r1 in the roll direction after the error is canceled.

12. The ball-balancing robot according to claim 10 , wherein the angle θ p is an angle between an axial line of the robot main body and the vertical axis when a gravity center of the robot main body is along the vertical axis.

13. The ball-balancing robot according to claim 10 , wherein
the robot main body includes a pitch-direction angular velocity sensor that detects an angular velocity in the pitch direction; and
the angle θ p is an actual inclination angle calculated based on the angular velocity detected by the pitch-direction angular velocity sensor.

14. The ball-balancing robot according to claim 1 , wherein the robot main body is moved in a horizontal direction at a constant velocity.

Assignees

• Murata Manufacturing Co

Inventors

• Tsuji Shigeru
• Kitagawa Mitsuru

Classifications

• H02K7/003

  Couplings; Details of shafts (means for mounting rotors on shafts H02K1/28) · CPC title

• G05D1/0891 Primary

  specially adapted for land vehicles · CPC title

• A63H33/005

  Motorised rolling toys · CPC title

• G01C9/02

  Details · CPC title

• A63H11/00

  Self-movable toy figures · CPC title