IEEE (Institute of Electrical and Electronics Engineers)
Doi
Abstract
The problem of communication delay in bilateral or
teleoperation systems is even more emphasized with the use of the
internet for communication, which may give rise to loss of
transparency and even instability. To address the problem,
numerous methods have been proposed. This study is among the
few recent studies taking a disturbance observer approach to the
problem of time delay, and introduces a novel sliding-mode
observer to overcome specifically the effects of communication
delay in the feedback loop. The observer operates in combination
with a PD+ controller which controls the system dynamics, while
also compensating load torque uncertainties on the slave side. To
this aim, an EKF based load estimation algorithm is performed on
the slave side. The performance of this approach is tested with
computer simulations for the teleoperation of a 1-DOF robotic
arm. The simulations reveal an acceptable amount of accuracy
and transparency between the estimated slave and actual slave
position under both constant and random measurement delay and
variable and step-type load variations on the slave side,
motivating the use of the approach for internet-based bilateral
control systems