文档介绍：Hybrid Control Design for a Wheeled Mobile
Robot
Thomas Bak 1, Jan Bendtsen 1, and Anders P. Ravn 2
1 Department of Control Engineering, University, Fredrik Bajers Vej 7C,
DK-9220 , Denmark, {tb,dimon}***@
2 Department puter Science, University, Fredrik Bajers Vej 7E,
DK-9220 , Denmark, ******@
Abstract. We present a hybrid systems solution to the problem of tra-
jectory tracking for a four-wheel steered four-wheel driven mobile robot.
The robot is modelled as a non-holonomic dynamic system subject to
pure rolling, no-slip constraints. Under normal driving conditions, a non-
linear trajectory tracking feedback control law based on dynamic feed-
back linearization is su cient to stabilize the system and ensure asymp-
totically stable tracking. Transitions to other modes are derived system-
atically from this model, whenever the con guration space of the con-
trolled system has some fundamental singular points. The stability of the
hybrid control scheme is nally analyzed using Lyapunov-like arguments.
1 Introduction
Wheeled mobile robots is an active research area with promising new applica-
tion domains. Mobile robots are mechanical systems characterized by challenging
(nonintegrable) constraints on the velocities which have led to numerous inter-
esting path tracking control solutions, see [16], [13], [4], and the recent survey of
non-holonomic control problems in [11]. Recently, [3] and [1] have addressed the
robot path tracking problem from a hybrid systems perspective. In this paper,
we consider a problem of plexity and develop a systematic approach
to derivation of a hybrid automaton and to stability analysis.
Our work is motivated by a project currently in progress, where an au-
tonomous four-wheel driven, four-wheel steered robot (Figure 1) is being de-
veloped. The project needs a robot that is able to survey an agricultural eld
autonomously. The vehicle has to navigate to certain waypoints wh