Cable force control method applicable to time-varying configuration

Patent metadata

Field	Value
Publication number	US-12409551-B2
Application number	US-202318398031-A
Country	US
Kind code	B2
Filing date	Dec 27, 2023
Priority date	Dec 12, 2022
Publication date	Sep 9, 2025
Grant date	Sep 9, 2025

Abstract

A cable force control method includes: establishing a friction model, and calibrating parameters; and calculating the parameters in real time, and controlling a force: identifying the parameters according to the friction model to obtain parameters of an auxiliary cable Bowden system and a power Bowden system: a friction coefficient μ a of the auxiliary cable Bowden system, and a friction coefficient μ p of the power cable Bowden system; calculating the auxiliary cable Bowden system θ a in real time according to the model and a force value of a sensor, and using same as a cable bending angle of the power cable Bowden system θ p ; and obtaining an inverse control formula F in =F out ·e −uλθ according to the friction model, and bringing the power cable Bowden system θ p into the inverse control formula to serve as a feedforward controller, so as to achieve an effect of real-time force control.

First claim

What is claimed is:

1. A cable force control method applicable to a time-varying configuration of a cable-driven system, the cable-driven system comprising a power cable Bowden system, an auxiliary cable Bowden system arranged adjacent to the power cable Bowden system, a plurality of tension sensors configured to measure forces on the Bowden systems, and a motor-driven actuator operably connected to the power cable Bowden system, the method comprising:
step 1, establishing a friction model, and calibrating parameters, wherein
a quasi-static equilibrium equation of a (s+ds) segment in a cable is indicated as:

{

d
⁢

F
⁡
(

s
,
t

)

=

λ
⁢

f
⁡
(

s
,
t

)

f
⁡
(

s
,
t

)

=

μ
⁢

N
⁡
(

s
,
t

)

N
⁡
(

s
,
t

)

=

F
⁡
(

s
,
t

)

⁢

κ
⁡
(

s
,
t

)

⁢
ds

F
′

(

s
,
t

)

=

[

F
⁡
(

s
+
ds

,
t

)

-

F
⁡
(

s
,
t

)

]

/
ds

,

(
1
)

wherein F(s,t), F(s+ds,t), N(s,t), f(s,t) and κ(s,t) indicate a cable tension at a position s, a cable tension at a position s+ds, a positive pressure, a friction force and curvature respectively under the condition of time t; λ=sign[F′(s)] is currently defined, such that

F
′

(

s
,
t

Assignees

• Univ Southeast

Inventors

• Li Huijun
• Lu Ye
• Song Aiguo
• Li Ye
• Xu Baoguo

Classifications

• B25J9/104

  with cables, chains or ribbons · CPC title

• B25J9/1653 Primary

  parameters identification, estimation, stiffness, accuracy, error analysis · CPC title

• B25J9/1633 Primary

  compliant, force, torque control, e.g. combined with position control · CPC title