Vision guided navigation for a nonholonomic mobile robot
Yi Ma; Kosecka, J.; Sastry, S.S.
Robotics and Automation, IEEE Transactions on
Volume 15, Issue 3, Jun 1999 Page(s):521 - 536
Digital Object Identifier 10.1109/70.768184
Summary:Theoretical and analytical aspects of the visual servoing problem
have not received much attention. Furthermore, the problem of estimation
from the vision measurements has been considered separately from the
design of the control strategies. Instead of addressing the pose
estimation and control problems separately, we attempt to characterize
the types of control tasks which can be achieved using only quantities
directly measurable in the image, bypassing the pose estimation phase.
We consider the task of navigation for a nonholonomic ground mobile base
tracking an arbitrarily shaped continuous ground curve. This tracking
problem is formulated as one of controlling the shape of the curve in
the image plane. We study the controllability of the system
characterizing the dynamics of the image curve, and show that the shape
of the image curve is controllable only up to its “linear”
curvature parameters. We present stabilizing control laws for tracking
piecewise analytic curves, and propose to track arbitrary curves by
approximating them by piecewise “linear” curvature curves.
Simulation results are given for these control schemes. Observability of
the curve dynamics by using direct measurements from vision sensors as
the outputs is studied and an extended Kalman filter is proposed to
dynamically estimate the image quantities needed for feedback control
from the actual noisy images
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