Position and Force Control of Teleoperation
System Based on PHANTOM Omni Robots
Rong Kong, Xiucheng Dong, and Xia Liu
School of Electrical Engineering and Electronic Information, Xihua University, No.999, Jinzhou Road, Jinniu District,
Chengdu 610039, P.R. China
Email: {kongrong2008, dxc}@163.com, xliu_uestc@yahoo.com
Abstract—Good position and force tracking are two
important performance requirements on teleoperation
system. However the external disturbances significantly
reduce the position and force tracking accuracy of
teleoperation system. To solve this problem, this paper
proposes a control method which combines backstepping
control and PID control to control the teleoperation system
based on PHANTOM Omni robots. PID controller is
designed for the master robot to achieve force tracking,
while backstepping controller is designed for the slave robot
to achieve position tracking. Furthermore, simulations are
conducted using MATLAB to verify the proposed method
for the teleoperation system, composed of two PHANTOM
Omni robots. Simulation results show that when the system
is subjected to external disturbances, the proposed method
which combines backstepping control and PID control can
ensure system stability and keep good position and force
tracking performance.
Index Terms—PHANTOM Omni robots, teleoperation
system, backstepping controller, PID controller, position
tracking, force tracking
I. INTRODUCTION
In the human-computer interaction process, the
computer responses to the behaviors of the operator
(including the operator’s position, action and speed).
Meanwhile, through this process reacts to the operator
through haptic devices. This is called force feedback. As
the interaction interface of the operator and the
environment, haptic devices allow the operator to get
force feedback of touching real object. PHANTOM Omni
Robot is such a force feedback device, which has been
widely applied in education, health care, gaming,
engineering and many other fields [1]. Alejandro Jarillo-
Silva [2] analyzed the mechanical structure of a single
PHANTOM Omni device as well as its hardware and
software environment. Haptically enabled surgical
simulation can allow users to be trained with realistic
haptic feedback in the medical field [3]. Lan Wang et al.
[4] explored an upper limb rehabilitaion training method
based on virtual reality interaction.
In robot teleoperation field, force feedback device is a
key equipment, The operator can achieve precise control
of slave robot through the master robot. Then the master
Manuscript received March 30, 2015; revised October 15, 2015.
feeds certain force information to the operator, so that the
operator can always change the control strategy. Even
without visual feedback, the operator can perform tasks in
distant places by via force feedback, which increases the
reliability of robot operation. Liu et al. [5] get a nonlinear
adaptive bilateral control method to solve the robot
system with uncertain dynamics and Kinematics
problems.
In this paper, the teleoperation system that composed
of two PHANTOM Omni robots is taken as control object.
The force and position control are achieved by a method
which combines backstepping control and PID control.
PID controller is designed for the master robot to achieve
the force tracking of the slave robot, while backstepping
controller is designed for the slave robot to track the
position of the master robot. It should be pointed out that
CCD camera feedback and real-time haptic feedback
control method was employed in [6], and the inverse
dynamics control of teleoperation was considered [7]. In
this paper we will investigate the position and force
control at the same time for the teleoperation system
which is composed of two PHANTOM Omni robots.
The rest of this paper is organized as follows. We first
introduce the model of teleoperation based on
PHANTOM Omni. Next, PID and backstepping
controllers are designed for the master and slave robots to
study the stability and motion tracking convergence of
the teleoperation system. Simulation results in Section III
show that the slave can follow the position of the master.
Besides, the force tracking performance is good. The
paper is concluded in Section IV.
II. MODEL OF TELEOPERATION BASED ON
PHANTOM OMNI
In this section, firstly the dynamic model of one robot
is given, then the model is extended to the dynamic and
model of teleoperation system based on two Phantom
Omni robots.
When interacting with a human and an environment,
the joint-space nonlinear dynamic models for an n-DOF
robot can be described as:
dqGqqqCqq )(),()(M
(1)
where
1
n
Rq
is the joint angle position,
nn
RqM
)(
is
the symmetric positive definite inertia matrix,
57
Journal of Mechanical Engineering and Robotics Research Vol. 5, No. 1, January 2016
doi: 10.18178/ijmerr.5.1.57-61
© 2016 Int. J. Mech. Eng. Rob. Res.