US 11,453,114 B2Granted

Full-state control method for the master-slave robot system with flexible joints and time-varying delays

AssigneeYanshan University

InventorsYana Yang, Changchun Hua, Junpeng Li, Lu Gan, Yilu Wang

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Abstract

A full-state control method for a master-slave robot system with flexible joints and time-varying delays is provided. In a teleoperation system formed by connecting a master robot and a slave robot through network, a proportional damping controller based on a position error and velocities, and a full-state feedback controller based on backstepping are designed for the master robot and the slave robot, respectively. High-dimension uniform accurate differentiators are designed to realize an exact difference to the virtual controllers. Delay-dependent stability criteria are established by constructing Lyapunov functions. Therefore, the criteria for selecting controller parameters are presented such that the global stability of the master-slave robot system with flexible joints and time-varying delays is realized. For the master-slave robot system with flexible joints, the global precise position tracking performance is realized by adopting a full-state feedback controller based on the backstepping method and the high-dimensional uniform accurate differentiators. Moreover, the global asymptotic convergence of the system is guaranteed and the robustness of the system is improved.

Claims6

Dependent claims

A full-state control method for a master-slave robot system with flexible joints and time-varying delays, comprising:

connecting a master robot and a slave robot through a network to form a teleoperation system;
measuring system parameters of the master robot and the slave robot, and measuring position and velocity information of joints and motors of the master robot and the slave robot in real-time;
controlling the master robot with a proportional damping controller and controlling the slave robot with a full-state feedback controller,
wherein a control torque provided by the proportional damping controller and a control torque provided by the full-state feedback controller are determined according to following formulas:
τ
m
=
-
k
m
⁡
(
X
m
⁢
1
-
X
s
⁢
1
⁡
(
t
-
T
s
⁡
(
t
)
)
)
-
α
m
⁢
X
m
⁢
2
τ
s
=
S
s
⁡
(
X
s
⁢
3
-
X
s
⁢
1
)
+
J
s
⁡
(
X
.
s
⁢
4
*
-
(
X
s
⁢
3
-
X
s
⁢
3
*
)
-
k
2
⁡
(
X
s
⁢
4
-
X
s
⁢
4
*
)
)
,
wherein, τm is the control torque provided by the proportional damping controller and τs is the control torque provided by the full-state feedback controller, X*s3 is a first virtual controller and X*s4 is a second virtual controller, {dot over (X)}*s4 is a first derivative of X*s4, Xm1 is a vector of joint displacements of the master robot, Xm2 is a vector of joint velocities of the master robot, Xs1 is a vector of joint displacement of the slave robot, Xs3 is a vector of motor positions of the slave robot, Xs4 is a vector of motor velocities of the slave robot, Ts(t) is a feedback time delay from the slave robot to the master robot, αm is a damping coefficient which is a positive constant, km is >0 a proportional coefficient, Ss is a diagonal positive-definite constant matrix which contains a joint stiffness of the slave robot, Js is a diagonal constant matrix of a moment of actuator inertia, and k2 is selected to be a positive constant.

98 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/145,442Filed 11 Jan 2021
Published: US 2021/0213602 A115 Jul 2021
Granted: 27 Sep 2022
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

B25J 3/00
Manipulators of leader-follower type, i.e. both controlling unit and controlled unit perform
B25J 9/1689
Characterised by the tasks executed: teleoperation
B25J 9/0084
Program-controlled manipulators: comprising a plurality of manipulators
G05B 2219/39195
Robotics, robotics to robotics hand: control, avoid oscillation, vibration due to low rigidity