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5 DISCUSSION
A compensation strategy to account for the negative
effects of a bilateral time-delay affecting a unicycle-
type mobile robot has been proposed. Several tech-
niques to accurately reproduce the time-delay in the
estimator have been presented, since this is required
and often a cause of concern in predictor-like control
strategies. Experiments show that the delay compen-
sation strategy is robust to small delay model mis-
matches and delay variations using the Internet as a
communication channel.
Future work includes a robustness analysis of
the delay compensation scheme and a comparison
with other predictor-like strategies. Additionally,
techniques to synchronize as precisely as possible
the controller and system sides are being studied in
order to obtain a more accurate measurement of the
system’s performance. Integrating the concept of
remote control of mobile robots with notions related
to the long distance synchronization of robotic net-
works and extending the concepts of the estimator to a
more general setting (other mechanical systems) also
remain topics to be addressed in the future.
ACKNOWLEDGEMENTS
The first author would like to dedicate this paper to
his father, Prof. Jaime Alvarez-Gallegos of CINVES-
TAV, M
´
exico, who was recently honored because of
his 60th birthday. Additionally, the authors acknowl-
edge the help of Hisashi Katsumata in conducting ex-
periments. This work has been supported by CONA-
CYT and SEP, M
´
exico, by the Graduate School of
Science and Engineering at TMU and the Japan So-
ciety for the Promotion of Science (JSPS) through
Grant-in-Aid for Scientific Research (No. 20560424).
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