Barycenter position determining method and apparatus, legged robot, and storage medium

Patent metadata

Field	Value
Publication number	US-12552028-B2
Application number	US-202217743296-A
Country	US
Kind code	B2
Filing date	May 12, 2022
Priority date	Apr 14, 2020
Publication date	Feb 17, 2026
Grant date	Feb 17, 2026

Abstract

A computing device creates first relation data indicating a relation between an interval duration and a center of mass position of a legged robot. The first relation data comprises a first constant, C. The computing device creates second relation data corresponding to at least one leg of for the legged robot and a force corresponding to the at last one leg with the ground. The second relation data comprises the first constant, C. The computing device creates third relation data according to the second relation data. The device determines a value of the first constant, C, when a target value J is a minimum value, and obtains the first relation data according to the determined value of the first constant, C.

First claim

What is claimed is:

1 . A center of mass position determining method performed by a control device connected to a legged robot, the method comprising:
creating first relation data, the first relation data indicating a relation between an interval duration t and a center of mass position P(t) of the legged robot, and wherein the center of mass position P(t) varies as a function of the interval duration t and a first constant C according to the first relation data; creating second relation data corresponding to the at least one leg of the legged robot, the second relation data indicating a relation between a force f i corresponding to the at least one leg with the ground and the center of mass position P(t), and wherein the force f i corresponding to the at least one leg with the ground varies as a function of the center of mass position P(t) and the first constant C according to the second relation data; creating third relation data based on the second relation data, the third relation data indicating a positive correlation between a target value J and a square of the force f i to which the at least one leg in contact with the ground is subjected, wherein the third relation data defines a quadratic programming problem in which the target value J varies as a function of a square of the force f i to which the at least one leg in contact with the ground is subjected; solving the quadratic programming problem by (i) applying different values for the first constant C to the center of mass position P(t) according to the first relation data and (ii) applying different values of the center of mass position P(t) corresponding to the different values for the first constant C to the force f i corresponding to the at least one leg with the ground according to the second relation data and (iii) applying different values of the force f i corresponding to the at least one leg with the ground to the target value J according to the third relation data until the target value J is minimized: determining, among the different values for the first constant C used for solving the quadratic programming problem, a value of the first constant C when the target value J is minimized as an optimized solution to the quadratic programming problem; and obtaining the first relation data according to the determined value of the first constant C, wherein the first relation data defines a trajectory of the center of mass position P(t) of the legged robot based on a movement of the legged robot as a function of time.

2 . The method according to claim 1 , wherein creating third relation data comprises:
creating the third relation data based on the first relation data and the second relation data corresponding to the at least one leg; and determining, based on the third relation data, the value of the first constant C when the target value J is the minimum value.

3 . The method according to claim 2 , wherein the creating first relation data comprises:
obtaining first state data and second state data of the legged robot in an initiation position and a termination position respectively, wherein the state data comprises at least center of mass positions, center of mass speeds, and center of mass accelerations; and creating the first relation data, wherein the first relation data comprises the first constant C, the first constant C comprises a second constant C free whose value is not determined and a third constant h whose value is determined, and the third constant h is determined based on the obtained state data.

4 . The method according to claim 2 , wherein creating the first relation data comprises:
setting the first relation data as follows: the center of mass position P(t) is a product of the first constant C and a duration matrix E; and

E
=

[

E
t

0

0

0

E
t

0

0

0

E
t

]

;

and
⁢

E
t

=

[

1

t

t
2

t
3

]

wherein E t represents a duration vector.

5 . The method according to claim 2 , wherein creating the second relation data comprises:
setting the second relation data corresponding to the at least one leg as follows: an acting force f i corresponding to an i th leg is a sum of the first constant C and a linear mapping of a fourth constant λ corresponding to the i th leg.

6 . The method according to claim 2 , wherein creating the third relation data based on the first relation data and the second relation data comprises:
obtaining a movement duration required for the legged robot to move from an initiation position to a termination position; selecting a plurality of sampling time points within the movement duration; determining, based on an interval duration between each sampling time point and a start time point and the first relation data, fourth relation data corresponding to the each sampling time point, wherein the fourth relation data indicates a relation between the first constant C and a sampling center of mass position Q(C), and the sampling center of mass position Q(C) indicates a center of mass position of the legged robot at the corresponding sampling time point; determining, based on the second relation data corresponding to the at least one leg and the fourth relation data, fifth relation data corresponding to the each sampling time point, wherein the fifth relation data indicates a relation between the first constant C and the acting force f i corresponding to the at least one leg; and creating the third relation data based on the fourth relation data and the fifth relation data, wherein the third relation data further indicates a positive correlation between the target value J and a square of the acting force f i corresponding to the at least on

Assignees

• Tencent Tech Shenzhen Co Ltd

Inventors

• Zheng Yu
• Jiang Xinyang
• Chi Wanchao
• Ling Yonggen
• Zhang Shenghao
• Zhang Zhengyou

Classifications

• B62D57/032 Primary

  with alternately or sequentially lifted supporting base and legs; with alternately or sequentially lifted feet or skid (B62D57/024 takes precedence) · CPC title

• B25J17/0283

  Three-dimensional joints · CPC title

• G05B2219/39215

  Adaptive control with stabilizing compensation · CPC title

• B25J9/1664 Primary

  characterised by motion, path, trajectory planning · CPC title