IP Library › Granted Patent US 12,625,503
Granted Patent B2
US 12,625,503 · App. 19/006,226 · Granted May 12, 2026

Robot control method, and computer-readable storage medium and wheel-legged biped robot using the same

Inventors: Meng Yan (Shenzhen, CN); Jiangchen Zhou (Shenzhen, CN); Chunyu Chen (Shenzhen, CN); Huan Tan (Shenzhen, CN)
Assignee: UBTECH ROBOTICS CORP LTD
G05D1/495B62D57/028G05D2109/12G05D2109/13
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Quick Facts
Patent No.
US 12,625,503
App. No.
19/006,226
Granted
May 12, 2026
Kind
B2
Abstract

A robot control method, and a computer-readable storage medium and a wheel-legged biped robot using the same are provided. The method includes: determining a kinetic model of the wheel-legged biped robot; determining, using the kinetic model, a sliding surface of the wheel-legged biped robot; determining, according to the sliding surface, a double power reaching law and a sliding mode control law of the wheel-legged biped robot; and controlling, according to the sliding surface, the double power reaching law and the sliding mode control law, the wheel-legged biped robot. Through the above-mentioned method, the adaptability of the wheel-legged biped robot to uncertain external disturbances can be enhanced, thereby improving its robustness to effectively maintain its balance even in the environment with complex terrain.

Claims (436)

1 . A method for controlling a wheel-legged biped robot, comprising:

determining a kinetic model of the wheel-legged biped robot;

determining, using the kinetic model, a sliding surface of the wheel-legged biped robot;

determining, according to the sliding surface, a double power reaching law and a sliding mode control law of the wheel-legged biped robot; and

controlling, according to the sliding surface, the double power reaching law and the sliding mode control law, the wheel-legged biped robot.

2 . The method of claim 1 , controlling, according to the sliding surface, the double power reaching law and the sliding mode control law, the wheel-legged biped robot comprises:

determining, according to the kinetic model and the sliding surface, an adaptive law of the wheel-legged biped robot; and

controlling, according to the sliding surface, the double power reaching law, the sliding mode control law and the adaptive law, the wheel-legged biped robot.

3 . The method of claim 2 , controlling, according to the sliding surface, the double power reaching law, the sliding mode control law and the adaptive law, the wheel-legged biped robot comprises:

determining, according to the sliding mode control law and the adaptive law, an adaptive sliding mode control law of the wheel-legged biped robot; and

controlling, according to the sliding surface, the double power reaching law and the adaptive sliding mode control law, the wheel-legged biped robot.

4 . The method of claim 1 , determining the kinetic model of the wheel-legged biped robot comprises:

determining parameters of a wheeled inverted pendulum model obtained by simplifying the wheel-legged biped robot; and

determining, according to the parameters of the wheeled inverted pendulum mode, the kinetic model of the wheel-legged biped robot.

5 . The method of claim 4 , determining the parameters of the wheeled inverted pendulum model obtained by simplifying the wheel-legged biped robot comprises:

simplifying the wheel-legged biped robot into the wheeled inverted pendulum model consisting of a body, two legs, and two wheels; and

determining, according to the wheeled inverted pendulum model, the parameters of the wheeled inverted pendulum model including one or more of a body mass, a wheel mass, a wheel radius, a distance between the two wheels, an inverted pendulum height, an inertia of the body around a preset three-dimensional coordinate system axis, an inertia of the wheel around the preset three-dimensional coordinate system axis, a forward angle, a tilt angle, and a steering angle.

6 . The method of claim 1 , determining, using the kinetic model, the sliding surface of the wheel-legged biped robot comprises:

determining the sliding surface of the wheel-legged biped robot based on an equation of:

S

=

[

s

1

s

2

]

=

e

.

+

λ

⁢

e

;

where, e is a system state error of the wheel-legged biped robot and e=X−X d =[e 1 e 3 ] T , X is an actual system state of the wheel-legged biped robot and X=[q 1 q 3 ] T , q 1 is an actual forward angle of the wheel-legged biped robot, q 3 is an actual steering angle of the wheel-legged biped robot, X d is a demanded system state of the wheel-legged biped robot and X d =[q 1d q 3d ] T , q 1d is a demanded forward angle of the wheel-legged biped robot, q 3d is a demanded steering angle of the wheel-legged biped robot, e 1 is a forward angle error of the wheel-legged biped robot, and e 3 is a steering angle error of the wheel-legged biped robot; S is the sliding surface, s 1 is a first component of the sliding surface, and s 2 is a second component of the sliding surface; λ is a parameter matrix of the sliding surface and

λ

=

[

λ

1

0

0

λ

2

]

,

 λ 1 is a first parameter of the sliding surface, and λ 2 is a second parameter of the sliding surface; and ė is an angular velocity error of the wheel-legged biped robot and ė=[ė 1 ė 3 ] T , ė 1 is a forward angular velocity error of the wheel-legged biped robot, and ė 3 is a steering angular velocity error of the wheel-legged biped robot.

7 . The method of claim 6 , determining, according to the sliding surface, the double power reaching law and the sliding mode control law of the wheel-legged biped robot comprises:

determining the double power reaching law of the wheel-legged biped robot based on an equation of:

S

.

=

-

k

1

[

❘

"\[LeftBracketingBar]"

s

1

❘

"\[RightBracketingBar]"

0

0

❘

"\[LeftBracketingBar]"

s

2

❘

"\[RightBracketingBar]"

]

δ

1

[

sgn

⁡

(

s

1

)

sgn

⁡

(

s

2

)

]

-

k

2

[

❘

"\[LeftBracketingBar]"

s

1

❘

"\[RightBracketingBar]"

0

0

❘

"\[LeftBracketingBar]"

s

2

❘

"\[RightBracketingBar]"

]

δ

2

[

sgn

⁡

(

s

1

)

sgn

⁡

(

s

2

)

]

=

-

k

1

[

❘

"\[LeftBracketingBar]"

s

1

❘

"\[RightBracketingBar]"

δ

1

sgn

⁡

(

s

1

)

❘

"\[LeftBracketingBar]"

s

2

❘

"\[RightBracketingBar]"

δ

1

sgn

⁡

(

s

2

)

]

-

k

2

[

❘

"\[LeftBracketingBar]"

s

1

❘

"\[RightBracketingBar]"

δ

2

sgn

⁡

(

s

1

)

❘

"\[LeftBracketingBar]"

s

2

❘

"\[RightBracketingBar]"

δ

2

sgn

⁡

(

s

2

)

]

;

where, sgn is a sign function; k 1 is a first reaching law parameter, and k 2 is a second reaching law parameter; and δ 1 is a first power parameter, δ 2 is a second power parameter, and δ 1 +δ 2 =2.

8 . A non-transitory computer-readable storage medium for storing one or more computer programs, wherein the one or more computer programs comprise:

instructions for determining a kinetic model of a wheel-legged biped robot;

instructions for determining, using the kinetic model, a sliding surface of the wheel-legged biped robot;

instructions for determining, according to the sliding surface, a double power reaching law and a sliding mode control law of the wheel-legged biped robot; and

instructions for controlling, according to the sliding surface, the double power reaching law and the sliding mode control law, the wheel-legged biped robot.

9 . The storage medium of claim 8 , wherein the instructions for controlling, according to the sliding surface, the double power reaching law and the sliding mode control law, the wheel-legged biped robot comprise:

instructions for determining, according to the kinetic model and the sliding surface, an adaptive law of the wheel-legged biped robot; and

instructions for controlling, according to the sliding surface, the double power reaching law, the sliding mode control law and the adaptive law, the wheel-legged biped robot.

10 . The storage medium of claim 9 , wherein the instructions for controlling, according to the sliding surface, the double power reaching law, the sliding mode control law and the adaptive law, the wheel-legged biped robot comprise:

instructions for determining, according to the sliding mode control law and the adaptive law, an adaptive sliding mode control law of the wheel-legged biped robot; and

instructions for controlling, according to the sliding surface, the double power reaching law and the adaptive sliding mode control law, the wheel-legged biped robot.

11 . The storage medium of claim 10 , wherein the instructions for determining the kinetic model of the wheel-legged biped robot comprise:

instructions for determining parameters of a wheeled inverted pendulum model obtained by simplifying the wheel-legged biped robot; and

instructions for determining, according to the parameters of the wheeled inverted pendulum mode, the kinetic model of the wheel-legged biped robot.

12 . The storage medium of claim 11 , wherein the instructions for determining the parameters of the wheeled inverted pendulum model obtained by simplifying the wheel-legged biped robot comprise:

instructions for simplifying the wheel-legged biped robot into the wheeled inverted pendulum model consisting of a body, two legs, and two wheels; and

instructions for determining, according to the wheeled inverted pendulum model, the parameters of the wheeled inverted pendulum model including one or more of a body mass, a wheel mass, a wheel radius, a distance between the two wheels, an inverted pendulum height, an inertia of the body around a preset three-dimensional coordinate system axis, an inertia of the wheel around the preset three-dimensional coordinate system axis, a forward angle, a tilt angle, and a steering angle.

13 . The storage medium of claim 8 , wherein the instructions for determining, using the kinetic model, the sliding surface of the wheel-legged biped robot comprise:

instructions for determining the sliding surface of the wheel-legged biped robot based on an equation of:

S

=

[

s

1

s

2

]

=

e

.

+

λ

⁢

e

;

where, e is a system state error of the wheel-legged biped robot and e=X−X d =[e 1 e 3 ] T , X is an actual system state of the wheel-legged biped robot and X=[q 1 q 3 ] T , q 1 is an actual forward angle of the wheel-legged biped robot, q 3 is an actual steering angle of the wheel-legged biped robot, X d is a demanded system state of the wheel-legged biped robot and X d =[q 1d q 3d ] T , q 1d is a demanded forward angle of the wheel-legged biped robot, q 3d is a demanded steering angle of the wheel-legged biped robot, e 1 is a forward angle error of the wheel-legged biped robot, and e 3 is a steering angle error of the wheel-legged biped robot; S is the sliding surface, s 1 is a first component of the sliding surface, and s 2 is a second component of the sliding surface; λ is a parameter matrix of the sliding surface and

λ

=

[

λ

1

0

0

λ

2

]

,

 λ 1 is a first parameter of the sliding surface, and λ 2 is a second parameter of the sliding surface; and ė is an angular velocity error of the wheel-legged biped robot and ė=[ė 1 ė 3 ] T , ė 1 is a forward angular velocity error of the wheel-legged biped robot, and ė 3 is a steering angular velocity error of the wheel-legged biped robot.

14 . A wheel-legged biped robot, comprising:

a processor;

a memory coupled to the processor; and

one or more computer programs stored in the memory and executable on the processor;

wherein, the one or more computer programs comprise:

instructions for determining a kinetic model of the wheel-legged biped robot;

instructions for determining, using the kinetic model, a sliding surface of the wheel-legged biped robot;

instructions for determining, according to the sliding surface, a double power reaching law and a sliding mode control law of the wheel-legged biped robot; and

instructions for controlling, according to the sliding surface, the double power reaching law and the sliding mode control law, the wheel-legged biped robot.

15 . The robot of claim 14 , wherein the instructions for controlling, according to the sliding surface, the double power reaching law and the sliding mode control law, the wheel-legged biped robot comprise:

instructions for determining, according to the kinetic model and the sliding surface, an adaptive law of the wheel-legged biped robot; and

instructions for controlling, according to the sliding surface, the double power reaching law, the sliding mode control law and the adaptive law, the wheel-legged biped robot.

16 . The robot of claim 15 , wherein the instructions for controlling, according to the sliding surface, the double power reaching law, the sliding mode control law and the adaptive law, the wheel-legged biped robot comprise:

instructions for determining, according to the sliding mode control law and the adaptive law, an adaptive sliding mode control law of the wheel-legged biped robot; and

instructions for controlling, according to the sliding surface, the double power reaching law and the adaptive sliding mode control law, the wheel-legged biped robot.

17 . The robot of claim 14 , wherein the instructions for determining the kinetic model of the wheel-legged biped robot comprise:

instructions for determining parameters of a wheeled inverted pendulum model obtained by simplifying the wheel-legged biped robot; and

instructions for determining, according to the parameters of the wheeled inverted pendulum mode, the kinetic model of the wheel-legged biped robot.

18 . The robot of claim 17 , wherein the instructions for determining the parameters of the wheeled inverted pendulum model obtained by simplifying the wheel-legged biped robot comprise:

instructions for simplifying the wheel-legged biped robot into the wheeled inverted pendulum model consisting of a body, two legs, and two wheels; and

instructions for determining, according to the wheeled inverted pendulum model, the parameters of the wheeled inverted pendulum model including one or more of a body mass, a wheel mass, a wheel radius, a distance between the two wheels, an inverted pendulum height, an inertia of the body around a preset three-dimensional coordinate system axis, an inertia of the wheel around the preset three-dimensional coordinate system axis, a forward angle, a tilt angle, and a steering angle.

19 . The robot of claim 14 , wherein the instructions for determining, using the kinetic model, the sliding surface of the wheel-legged biped robot comprise:

instructions for determining the sliding surface of the wheel-legged biped robot based on an equation of:

S

=

[

s

1

s

2

]

=

e

.

+

λ

⁢

e

;

where, e is a system state error of the wheel-legged biped robot and e=X−X d =[e 1 e 3 ] T , X is an actual system state of the wheel-legged biped robot and X=[q 1 q 3 ] T , q 1 is an actual forward angle of the wheel-legged biped robot, q 3 is an actual steering angle of the wheel-legged biped robot, X d is a demanded system state of the wheel-legged biped robot and X d =[q 1d q 3d ] T , q 1d is a demanded forward angle of the wheel-legged biped robot, q 3d is a demanded steering angle of the wheel-legged biped robot, e 1 is a forward angle error of the wheel-legged biped robot, and e 3 is a steering angle error of the wheel-legged biped robot; S is the sliding surface, s 1 is a first component of the sliding surface, and s 2 is a second component of the sliding surface; λ is a parameter matrix of the sliding surface and

λ

=

[

λ

1

0

0

λ

2

]

,

 λ 1 is a first parameter of the sliding surface, and λ 2 is a second parameter of the sliding surface; and ė is an angular velocity error of the wheel-legged biped robot and ė=[ė 1 ė 3 ] T , ė 1 is a forward angular velocity error of the wheel-legged biped robot, and ė 3 is a steering angular velocity error of the wheel-legged biped robot.

20 . The robot of claim 19 , wherein the instructions for determining, according to the sliding surface, the double power reaching law and the sliding mode control law of the wheel-legged biped robot comprise:

instructions for determining the double power reaching law of the wheel-legged biped robot based on an equation of:

S

.

=

-

k

1

[

❘

"\[LeftBracketingBar]"

s

1

❘

"\[RightBracketingBar]"

0

0

❘

"\[LeftBracketingBar]"

s

2

❘

"\[RightBracketingBar]"

]

δ

1

[

sgn

⁡

(

s

1

)

sgn

⁡

(

s

2

)

]

-

k

2

[

❘

"\[LeftBracketingBar]"

s

1

❘

"\[RightBracketingBar]"

0

0

❘

"\[LeftBracketingBar]"

s

2

❘

"\[RightBracketingBar]"

]

δ

2

[

sgn

⁡

(

s

1

)

sgn

⁡

(

s

2

)

]

=

-

k

1

[

❘

"\[LeftBracketingBar]"

s

1

❘

"\[RightBracketingBar]"

δ

1

sgn

⁡

(

s

1

)

❘

"\[LeftBracketingBar]"

s

2

❘

"\[RightBracketingBar]"

δ

1

sgn

⁡

(

s

2

)

]

-

k

2

[

❘

"\[LeftBracketingBar]"

s

1

❘

"\[RightBracketingBar]"

δ

2

sgn

⁡

(

s

1

)

❘

"\[LeftBracketingBar]"

s

2

❘

"\[RightBracketingBar]"

δ

2

sgn

⁡

(

s

2

)

]

;

where, sgn is a sign function: k 1 is a first reaching law parameter, and k 2 is a second reaching law parameter; and δ 1 is a first power parameter, δ 2 is a second power parameter, and δ 1 +δ 2 =2.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 31, 2024
From: YAN, MENG; ZHOU, JIANGCHEN; CHEN, CHUNYU; TAN, HUAN
To: UBTECH ROBOTICS CORP LTD
Reel/Frame 069819/0353 →
Priority Claims (1)
CN 202410132737.2 · Jan 30, 2024 · national
Continuity (1)
Related Publication 20250244769A1 · Jul 31, 2025
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