Robot motion control method and apparatus

Patent metadata

Field	Value
Publication number	US-12330309-B2
Application number	US-202217983553-A
Country	US
Kind code	B2
Filing date	Nov 9, 2022
Priority date	Jan 28, 2021
Publication date	Jun 17, 2025
Grant date	Jun 17, 2025

Abstract

This disclosure is related to a robot motion control method and apparatus. The method includes: obtaining a center-of-mass reference trajectory used for guiding the robot to execute a target motion; obtaining, based on optimization of an objective function, center-of-mass control information for controlling the robot to follow the center-of-mass reference trajectory to move; generating joint control information according to the center-of-mass control information and a structure matrix of the robot; and controlling the robot to execute the target motion based on the joint control information.

First claim

What is claimed is:

1. A robot motion control method, applied to a robot, the method comprising:
obtaining a center-of-mass reference trajectory for guiding the robot to execute a target motion; the center-of-mass reference trajectory being a center-of-mass motion trajectory of the robot configured to achieve the target motion;
determining desired center-of-mass motion data of the robot based on the center-of-mass reference trajectory, the desired center-of-mass motion data being a desired value of motion data associated with a center of mass of the robot;
constructing an objective function based on the desired center-of-mass motion data and matrix data constructed based on a position relationship between the center of mass of the robot and contact points, the contact points being contact points between the robot and an environment, a value of the objective function is representing a degree of deviation of the robot from the center-of-mass reference trajectory, wherein the objective function is:
J qp =( w des −Af ) T W w ( w des −Af ),

where W w denotes a positive definite weight matrix, w des denotes the desired center-of-mass motion data, A denotes the matrix and f denotes the center-of-mass control information;
calculating center-of-mass control information enabling the value of the objective function to satisfy an optimization stop condition;
generating joint control information according to the center-of-mass control information and a structure matrix of the robot; and
controlling the robot to execute the target motion based on the joint control information.

2. The method according to claim 1 , wherein the calculating the center-of-mass control information comprises:
utilizing quadratic programming (QP) optimization to calculate the center-of-mass control information.

3. The method according to claim 1 , wherein the calculating the center-of-mass control information comprises:
utilizing interior point optimizer (IPOPT) optimization to calculate the center-of-mass control information.

4. The method according to claim 1 , wherein the obtaining the desired center-of-mass motion data of the robot based on the center-of-mass reference trajectory comprises:
obtaining actual center-of-mass motion data of the robot;
obtaining reference center-of-mass motion data of the robot according to the center-of-mass reference trajectory;
obtaining a center-of-mass motion data adjustment value according to a difference between the actual center-of-mass motion data and the reference center-of-mass motion data; and
obtaining the desired center-of-mass motion data according to the center-of-mass motion data adjustment value and the reference center-of-mass motion data.

5. The method according to claim 4 , wherein the obtaining the center-of-mass motion data adjustment value according to the difference between the actual center-of-mass motion data and the reference center-of-mass motion data comprises:
calculating a difference between the actual center-of-mass motion data and the reference center-of-mass motion data; and
obtaining the center-of-mass motion data adjustment value according to a gain matrix and the difference, the gain matrix corresponding to the motion data associated with the center of mass of the robot.

6. The method according to claim 4 , wherein the center-of-mass motion data adjustment value comprises a center-of-mass acceleration adjustment value and a center-of-mass angular acceleration adjustment value.

7. The method according to claim 6 , wherein the center-of-mass acceleration adjustment value is represented by {umlaut over (p)} c adj =K d c ({dot over (p)} c ref −{dot over (p)} c act )+K p c (p c ref −p c act ), where {umlaut over (p)} c adj denotes a center-of-mass acceleration adjustment value, {dot over (p)} c ref denotes a reference center-of-mass velocity, {dot over (p)} c act denotes an actual center-of-mass velocity, p c ref denotes a reference center-of-mass position, p c act denotes an actual center-of-mass position, K d c and K p c denote gain matrices associated with center-of-mass acceleration.

8. The method according to claim 6 , wherein the center-of-mass angular acceleration adjustment value is represented by {dot over (ω)} adj =K d ω (ω ref −ω act )+K p ω (R ref R act ) V , where {dot over (ω)} adj denotes a center-of-mass angular acceleration adjustment value, ω ref denotes a reference center-of-mass angular velocity, ω act denotes an actual center-of-mass angular velocity, R ref denotes a reference rotation matrix of a center-of-mass coordinate system relative to a world coordinate system, R act denotes an actual rotation matrix of the center-of-mass coordinate system relative to the world coordinate system, (R ref R act ) V denotes a rotation vector from R act to R ref , and K p ω and K d ω denote gain matrices associated with center-of-mass angular acceleration.

9. The method according to claim 1 , wherein the method further comprises:
performing kinetics analysis on a particle model to obtain a kinetics equation, the particle model being obtained by simplification based on a robot body; and
analyzing the kinetics equation and constructing the objective function based on an objective of making the center-of-mass motion trajectory of the robot consistent with the center-of-mass reference trajectory.

10. The method according to claim 1 , wherein the generating the joint control information according to the center-of-mass control information and the structure matrix of the robot comprises:
generating intermediate joint control information according to the center-of-mass control information and the structure matrix corresponding to the robot;
obtaining actual joint motion data of the robot;
obtaining reference joint motion data of the robot; and
adjusting the intermediate joint control information according to the actual joint motion data and the reference joint motion data to obtain the joint control information.

11. The method according to claim 10 , wherein the joint control information comprises joint torque represented by τ=−J τ T f opt +K d q ({dot over (q)} ref −{dot over (q)} act )+K p q (q ref −q act ), where τ denotes joint torque, J τ denotes the structure matrix corresponding to the robot, f opt denotes the center-of-mass control information obtained by optimization, {dot over (q)} ref denotes a reference joint angular velocity, {dot over (q)} act denotes an actual joint angular velocity, q ref denotes a reference joint angle, q act denotes an actual joint angle, and K p q and K d q are gain matrices associated with the joint torque.

12. The method according to claim 11 , wherein the robot is a quadruped robot, and the target motion is a motion process from a four-legged lying down state to a two-legged standing state.

13. A robot motion control apparatus, comprising:
a memory operable to store computer-readable instructions; and
a processor circuitry operable to read the computer-readable instructions, the processor circuitry when executing the computer-readable instructions is configured to:
obtain a center-of-mass reference trajectory for guiding the robot to execute a target motion; the center-of-mass reference trajectory being a center-of-mass motion trajectory of the robot configured to achieve the target motion;
determine desired center-of-mass motion data of the robot based on the center-of-mass reference trajectory, the desired center-of-mass motion data being a desired value of motion data associated with a center of mass of the robot;
construct an objective function based on the desired

Assignees

• Tencent Tech Shenzhen Co Ltd

Inventors

• Zhou Qinqin
• Chen Xiangyu
• Zheng Yu
• Xu Liangwei
• Yang Sicheng
• Xiong Kun

Classifications

• B25J9/06

  characterised by multi-articulated arms · CPC title

• B25J11/008

  Manipulators for service tasks · CPC title

• B25J9/1607

  Calculation of inertia, jacobian matrixes and inverses · CPC title

• B25J9/1664 Primary

  characterised by motion, path, trajectory planning · CPC title

• 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