Robot control method, robot and computer-readable storage medium

Patent metadata

Field	Value
Publication number	US-12533797-B2
Application number	US-202418424323-A
Country	US
Kind code	B2
Filing date	Jan 26, 2024
Priority date	Jan 28, 2023
Publication date	Jan 27, 2026
Grant date	Jan 27, 2026

Abstract

A robot control method includes: building a two-wheeled inverted pendulum model based on a wheel-legged robot; constructing initial state-space equations based on the two-wheeled inverted pendulum model; linearizing the initial state-space equations to obtain the state-space equations for a linear time-invariant system; obtaining a quadratic performance objective function according to the state-space equations for the linear time-invariant system; and solving the quadratic performance objective function by a linear quadratic regulator to obtain wheel torques of the wheel-legged robot, and controlling the wheel-legged robot according to the wheel torques.

First claim

What is claimed is:

1. A computer-implemented robot control method comprising:
building a two-wheeled inverted pendulum model based on a wheel-legged robot;
constructing initial state-space equations based on the two-wheeled inverted pendulum model;
linearizing the initial state-space equations to obtain the state-space equations for a linear time-invariant system;
obtaining a quadratic performance objective function according to the state-space equations for the linear time-invariant system; and
solving the quadratic performance objective function by a linear quadratic regulator to obtain wheel torques of the wheel-legged robot, and controlling the wheel-legged robot according to the wheel torques.

2. The method of claim 1 , wherein controlling the wheel-legged robot according to the wheel torques comprises:
using the wheel torques as control commands, and inputting the control commands into wheel motors of the wheel-legged robot;
controlling the wheel motors to output torques that are respectively equal to the wheel torques according to the control commands.

3. The method of claim 2 , further comprising:
obtaining a plurality of actual state variables of the wheel-legged robot after the wheel motors output the torques that are respectively equal to the wheel torques.

4. The method of claim 1 , further comprising:
performing forward kinematics analysis on a leg planar five-bar mechanism of the wheel-legged robot to obtain a system of equations for foot endpoints of the wheel-legged robot;
obtaining a foot endpoint vector expression according to the system of equations;
obtaining a velocity Jacobian matrix of a leg parallel structure of the wheel-legged robot according to the foot endpoint vector expression;
determining a mapping relationship between the velocity Jacobian matrix, hip joint driving torque vectors and two-dimensional contact forces applied to the foot endpoints based on a principle of virtual work;
incorporating virtual spring-damper elements into the wheel-legged robot and establishing a feedback control framework; and
obtaining hip joint driving torques of the wheel-legged robot based on the feedback control framework and the mapping relationship, and controlling the wheel-legged robot according to the hip joint driving torques.

5. The method of claim 4 , wherein obtaining hip joint driving torques of the wheel-legged robot based on the feedback control framework and the mapping relationship comprises:
calculating the two-dimensional contact forces based on the feedback control framework; and
calculating the hip joint driving torques based on the calculated two-dimensional contact forces and the mapping relationship.

6. The method of claim 5 , wherein incorporating virtual spring-damper elements into the wheel-legged robot and establishing the feedback control framework comprises:
arranging the virtual spring-damper elements in a first direction and a second direction of the foot endpoints of the wheel-legged robot, as well as in a roll direction of the wheel-legged robot, to establish a three-channel feedback control framework.

7. The method of claim 4 , wherein obtaining the velocity Jacobian matrix of the leg parallel structure of the wheel-legged robot according to the foot endpoint vector expression comprises:
performing total differential processing on the foot endpoint vector expression to obtain a total differential expression; and
determining the velocity Jacobian matrix according to the total differential expression.

8. A robot comprising:
one or more processors; and
a memory coupled to the one or more processors, the memory storing programs that, when executed by the one or more processors, cause performance of operations comprising:
building a two-wheeled inverted pendulum model based on a wheel-legged robot;
constructing initial state-space equations based on the two-wheeled inverted pendulum model;
linearizing the initial state-space equations to obtain the state-space equations for a linear time-invariant system;
obtaining a quadratic performance objective function according to the state-space equations for the linear time-invariant system; and
solving the quadratic performance objective function by a linear quadratic regulator to obtain wheel torques of the wheel-legged robot, and controlling the wheel-legged robot according to the wheel torques.

9. The robot of claim 8 , wherein controlling the wheel-legged robot according to the wheel torques comprises:
using the wheel torques as control commands, and inputting the control commands into wheel motors of the wheel-legged robot;
controlling the wheel motors to output torques that are respectively equal to the wheel torques according to the control commands.

10. The robot of claim 9 , wherein the operations further comprise:
obtaining a plurality of actual state variables of the wheel-legged robot after the wheel motors output the torques that are respectively equal to the wheel torques.

11. The robot of claim 8 , wherein the operations further comprise:
performing forward kinematics analysis on a leg planar five-bar mechanism of the wheel-legged robot to obtain a system of equations for foot endpoints of the wheel-legged robot;
obtaining a foot endpoint vector expression according to the system of equations;
obtaining a velocity Jacobian matrix of a leg parallel structure of the wheel-legged robot according to the foot endpoint vector expression;
determining a mapping relationship between the velocity Jacobian matrix, hip joint driving torque vectors and two-dimensional contact forces applied to the foot endpoints based on a principle of virtual work;
incorporating virtual spring-damper elements into the wheel-legged robot and establishing a feedback control framework; and
obtaining hip joint driving torques of the wheel-legged robot based on the feedback control framework and the mapping relationship, and controlling the wheel-legged robot according to the hip joint driving torques.

12. The robot of claim 11 , wherein obtaining hip joint driving torques of the wheel-legged robot based on the feedback control framework and the mapping relationship comprises:
calculating the two-dimensional contact forces based on the feedback control framework; and
calculating the hip joint driving torques based on the calculated two-dimensional contact forces and the mapping relationship.

13. The robot of claim 12 , wherein incorporating virtual spring-damper elements into the wheel-legged robot and establishing the feedback control framework comprises:
arranging the virtual spring-damper elements in a first direction and a second direction of the foot endpoints of the wheel-legged robot, as well as in a roll direction of the wheel-legged robot, to establish a three-channel feedback control framework.

14. The robot of claim 11 , wherein obtaining the velocity Jacobian matrix of the leg parallel structure of the wheel-legged robot according to the foot endpoint vector expression comprises:
performing total differential processing on the foot endpoint vector expression to obtain a total differential expression; and
determining the velocity Jacobian matrix according to the total differential expression.

15. A non-transitory computer-readable storage medium storing instructions that, when executed by at least one processor of a robot, cause the at least one processor to perform a method, the method comprising:
building a two-wheeled inverted pendulum model based on a wheel-legged robot;
constructing initial state-space equations based on the two-wheeled inverted pendulum model;
linearizing

Assignees

• Ubtech Robotics Corp Ltd

Inventors

• Tao Bo
• Chen Chunyu

Classifications

• B62D57/028

  having wheels and mechanical legs (B62D57/024 takes precedence; ground-engaging vehicle fittings for supporting, lifting or manoeuvring the vehicle, wholly or in part B60S9/00) · CPC title

• B60L15/20

  for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed · CPC title

• B25J9/1607 Primary

  Calculation of inertia, jacobian matrixes and inverses · CPC title

• B62D57/032

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

• Y02T10/72

  Electric energy management in electromobility · CPC title