Robot stability control method, robot and computer-readable storage medium

Patent metadata

Field	Value
Publication number	US-12275152-B2
Application number	US-202218071462-A
Country	US
Kind code	B2
Filing date	Nov 29, 2022
Priority date	Dec 17, 2021
Publication date	Apr 15, 2025
Grant date	Apr 15, 2025

Abstract

A robot stability control method includes: obtaining a desired zero moment point (ZMP) and a fed-back actual ZMP of a robot at a current moment; based on a ZMP tracking control model, the desired ZMP and the actual ZMP, calculating a desired value of a motion state of a center of mass of the robot at the current moment, wherein the desired value of the motion state of the center of mass comprises a correction amount of the position of the center of mass; based on a spring-mass-damping-acceleration model and the desired value of the motion state of the center of mass, calculating a lead control input amount for the correction amount of the position of the center of mass; and controlling motion of the robot according to the lead control input amount and a planned value of the position of the center of mass at the current moment.

First claim

What is claimed is:

1. A computer-implemented robot stability control method, comprising:
obtaining a desired zero moment point (ZMP) and a fed-back actual ZMP of a robot at a current moment;
based on a ZMP tracking control model, the desired ZMP and the actual ZMP, calculating a desired value of a motion state of a center of mass of the robot at the current moment, wherein the desired value of the motion state of the center of mass comprises a correction amount of the position of the center of mass, and wherein the ZMP tracking control model takes the desired ZMP and the actual ZMP as an input of the ZMP tracking control model, and takes the desired value of the motion state of the center of mass as an output;
based on a spring-mass-damping-acceleration model and the desired value of the motion state of the center of mass, calculating a lead control input amount for the correction amount of the position of the center of mass; and
controlling motion of the robot according to the lead control input amount and a planned value of the position of the center of mass at the current moment, so as to realize tracking of the desired ZMP by the robot;
wherein the spring-mass-damping-acceleration model is created by adding a second mass block to a spring-mass-damping model that includes a first mass block, the second mass block and a desired acceleration are configured to generate a force on the first mass block; a dynamic equation of the spring-mass-damping-acceleration model is obtained by performing force balance analysis on the first mass block, the dynamic equation of the spring-mass-damping-acceleration model is configured to calculate the lead control input amount for the correction amount of the position of the center of mass when the robot performs ZMP tracking.

2. The method of claim 1 , wherein the desired value of the motion state of the center of mass further comprises a desired velocity of the center of mass and a desired acceleration of the center of mass; calculating the lead control input amount for the correction amount of the position of the center of mass based on the spring-mass-damping-acceleration model and the desired value of the motion state of the center of mass comprises:
calculating a force on the center of mass of the robot at the current moment using a discrete equation of state of the spring-mass-damping-acceleration model according to the correction amount of the position of the center of mass, the desired velocity of the center of mass and desired acceleration of the center of mass, wherein the discrete equation of state is obtained by discretizing the dynamic equation of the spring-mass-damping-acceleration model; and
obtaining the lead control input amount for the correction amount of the position of the center of mass at the current moment according to the force on the center of mass of the robot at the current moment and the lead control input amount for the correction amount of the position of the center of mass at a previous moment.

3. The method of claim 2 , wherein the discrete equation of state is as follows: F k =k s ×Δx c k d +k d ×Δ{dot over (x)} c k d +m×Δ{umlaut over (x)} c k d ;

Δ
⁢

x
ck

=

Δ
⁢

x

ck
-
1

×

e

(

-

k
s

/

k
d

)

*
Δ
⁢
t

-

F
k

M

×

(

e

(

-

k
s

/

k
d

)

*
Δ
⁢
t

-
1.

)

k
s

,

where F k represents the force on the center of mass of the robot at time k, k s , k d , M and m represent a stiffness coefficient of a spring, a damping coefficient of a damper, a mass of the first mass block and a mass of the second mass block, respectively, Δx c k d , Δ{dot over (x)} c k d and Δ{umlaut over (x)} c k d represent a desired position, the desired velocity and the desired acceleration of the center of mass at time k, respectively, Δx c k and Δx c k-1 , represent the lead control input amount of the position of the center of mass at time k and time k−1, respectively, Δt represents an interval time between time k and time k−1.

4. The method of claim 1 , wherein obtaining the desired ZMP of the robot at the current moment comprises:
simplifying the robot into a linear inverted pendulum model, and calculating a planned capture point of the robot at the current moment according to planned values of the position of the center of mass and a velocity of the center of mass of the robot;
calculating a measured capture point of the robot at the current moment according to measured values of the position of the center of mass and the velocity of the center of mass of the robot; and
calculating the desired ZMP of the robot at the current moment according to the planned capture point and the measured capture point and based on a position relationship between a capture point and the ZMP of the robot, wherein the position relationship between the capture point and the ZMP of the robot is determined according to a preset relationship between the capture point and the position of the center

Assignees

• Ubtech Robotics Corp Ltd

Inventors

• Ge Ligang
• Lìu Yizhang
• Chen Chunyu
• Luo Qiuyue
• Zhou Jiangchen
• Yan Meng
• Xiong Youjun

Classifications

• G05B2219/50391

  Robot · CPC title

• G05B19/4155

  characterised by program execution, i.e. part program or machine function execution, e.g. selection of a program · CPC title

• B25J9/1605

  Simulation of manipulator lay-out, design, modelling of manipulator · CPC title

• G05B2219/40467

  Virtual springs, impedance method · CPC title

• G05B2219/40077

  Posicast, inverted pendulum, acrobat, balance rod · CPC title