Method for maintaining stability of mobile robot and mobile robot thereof

Patent metadata

Field	Value
Publication number	US-11334094-B2
Application number	US-201916557071-A
Country	US
Kind code	B2
Filing date	Aug 30, 2019
Priority date	Jul 15, 2019
Publication date	May 17, 2022
Grant date	May 17, 2022

Abstract

Disclosed is a mobile robot having a receiving unit and capable of moving, the mobile robot including: at least three wheels arranged at a lower portion of the mobile robot; a sensing unit configured to measure a weight of the mobile robot applied to each of the at least three wheels; a linear actuator connected to the receiving unit and configured to apply a linear motion to the receiving unit in a direction toward a front section or a rearward section of the mobile robot; and a processor configured to, based on the weight applied to each of the at least three wheels measured by the sensing unit, control the linear actuator so as to apply the linear motion to the receiving unit. In addition, disclosed are a method for controlling a center of mass of a mobile robot, including a method performed by the aforementioned mobile robot, and a non-volatile computer readable storage medium in which a computer program for implementing the aforementioned method is stored.

First claim

What is claimed is:

1. A mobile robot having a receiving unit and capable of moving, the mobile robot comprising:
at least three wheels arranged at a lower portion of the mobile robot;
a sensor configured to measure a weight of the mobile robot applied to each of the at least three wheels;
a linear actuator connected to the receiving unit and configured to apply a linear motion to the receiving unit in a direction toward a front section or a rear section of the mobile robot; and
a processor configured to, based on the weight applied to each of the at least three wheels measured by the sensor, control the linear actuator so as to apply the linear motion to the receiving unit,
wherein the processor is further configured to control the linear actuator when a difference between weights applied to the at least three wheels falls within a predetermined range and lasts for a period exceeding a predetermined threshold time.

2. The mobile robot of claim 1 , wherein the processor is further configured to:
determine whether a center of mass of the mobile robot is biased toward the front section or the rear section, and
control the linear actuator so as to apply the linear motion to the receiving unit in a direction opposite to a direction toward the center of mass of the mobile robot is biased.

3. The mobile robot of claim 1 , further comprising a linear guide device configured to guide the linear motion.

4. The mobile robot of claim 3 , wherein the linear guide device is arranged between an outer wall of the mobile robot and the receiving unit.

5. The mobile robot of claim 3 , wherein the linear guide device includes a predetermined block to allow the receiving unit to move on the linear guide device, and
wherein the linear guide device and the receiving unit are connected through the predetermined block.

6. The mobile robot of claim 1 , wherein the processor is further configured to control the linear actuator so that uniform weights are applied to the at least three wheels.

7. The mobile robot of claim 1 , wherein the processor is further configured to control the linear actuator so as to apply the linear motion to the receiving unit in a moving direction of the mobile robot when the mobile robot moves to a sloped ground which is biased upward.

8. The mobile robot of claim 1 , wherein the processor is further configured to control the linear actuator so as to apply the linear motion to the receiving unit in an opposite direction of a moving direction of the mobile robot when the mobile robot moves to a sloped ground which is biased downward.

9. The mobile robot of claim 1 , wherein the mobile robot further comprises an output unit, and
wherein the processor is configured to control the output unit to output an alarm signal based on whether a center of mass of the mobile robot is biased and is positioned within a predetermined distance from a stable region.

10. The mobile robot of claim 1 , further comprising a plurality of linear guide devices configured to guide the linear motion.

11. A method for controlling a center of mass of a mobile robot, the method comprising:
measuring weights of the mobile robot applied to at least three wheels arranged at a lower portion of the mobile robot; and
based on a weight applied to each of the at least three wheels, controlling a linear actuator so as to apply a linear motion to a receiving unit included in the mobile robot in a direction toward a front section or a rear section of the mobile robot,
wherein the controlling of the linear actuator comprises controlling the linear actuator when a difference between the weights applied to the at least three wheels falls within a predetermined range and lasts for a period exceeding a predetermined threshold time.

12. The method of claim 11 , wherein the controlling of the linear actuator further comprises:
determining whether the center of mass of the mobile robot is biased toward the front section or the rear section; and
controlling the linear actuator so as to apply the linear motion to the receiving unit in a direction opposite to a direction toward which the center of mass is biased.

13. The method of claim 12 , wherein the controlling of the linear actuator further comprises controlling the linear actuator so as to apply the linear motion to the receiving unit in the direction, which is opposite to the direction toward which the center of mass of the mobile robot is biased, along a linear guide device that guides the linear motion.

14. The method of claim 11 , wherein the controlling of the linear actuator further comprises controlling the linear actuator so that uniform weights are applied to the at least three wheels.

15. The method of claim 11 , wherein the controlling of the linear actuator further comprises controlling the linear actuator so as to apply the linear motion to the receiving unit in a moving direction of the mobile robot when the mobile robot moves to a sloped ground which is biased upward.

16. The method of claim 11 , wherein the controlling of the linear actuator further comprises controlling the linear actuator so as to apply the linear motion to the receiving unit in an opposite direction of a moving direction of the mobile robot when the mobile robot moves to a sloped ground which is biased downward.

17. The method of claim 11 , wherein the method further comprises outputting an alarm signal based on whether the center of mass of the mobile robot is biased and is positioned within a predetermined distance from a stable region.

18. A method for controlling a center of mass of a mobile robot, the method comprising:
measuring weights of the mobile robot applied to at least three wheels arranged at a lower portion of the mobile robot; and
based on a weight applied to each of the at least three wheels, controlling a linear actuator so as to apply a linear motion to a receiving unit included in the mobile robot in a direction toward a front section or a rear section of the mobile robot,
wherein the method further comprises outputting an alarm signal based on whether the center of mass of the mobile robot is biased and is positioned within a predetermined distance from a stable region.

Assignees

• Lg Electronics Inc

Inventors

• Lee Sanghak
• Kim Nakyeong
• Moon Sungmin
• Seo Jeongkyo

Classifications

• G05D1/0891 Primary

  specially adapted for land vehicles · CPC title

• B25J5/007

  mounted on wheels · CPC title

• B62D61/06

  with only three wheels · CPC title

• B62D63/02

  Motor vehicles · CPC title

• B25J11/00 Primary

  Manipulators not otherwise provided for · CPC title