TITLE:
Dynamic Based SMC of Nonholonomic Mobile Robots
AUTHORS:
Jafar Keighobadi, Mohammad Sadeghi Shahidi, Abazar Nezafat Khajeh, Khadijeh Alioghli Fazeli
KEYWORDS:
Sliding Mode Control; Mobile Robot Dynamics; Robustness; Feedback Linearization
JOURNAL NAME:
Positioning,
Vol.4 No.2,
May
22,
2013
ABSTRACT: The aim of the paper is trajectory
tracking control of a non-holonomic mobile robot whose centroid doesn’t
coincide to its rotation center in the middle of connecting axle of driving wheels. The nonholonomic
dynamic model of the Wheeled Mobile Robot (WMR) is developed in global
Cartesian coordinates where the WMR’s forward and angular velocities are used
as internal state variables. In order to include the effects of parameter
uncertainties, measurement noises and other anomalies in the WMR system, a
bounded perturbation vector is embedded to the developed dynamical model.
Through defining the control inputs by computed torque method, a Dynamic Sliding
Mode Controller (DSMC) is proposed to stabilize the
sliding surfaces. Based on the proposed robust control system, the effect of
uncertainties and noises in the robot performance is attenuated. By use of the
WMR forward and angular velocities as internal state variables in the dynamic modeling, the
developed model is relatively simple and mainly independent of the robot
states. This makes the dynamical model more robust against measurement errors.
Design of the DSMC based on such a model leads to perfect trajectory tracking
and compensation for initial off-tracks even in the presence of disturbances
and modeling uncertainties.