If the next checkpoint is changed, the window angle can be reset to the
default or left at the maximum value, depending on the application. If the
checkpoints are given too close together, this algorithm gives the nodes the
option of re-sampling dynamically.
The algorithm terminates when the destination node is within the search
window, or a next hop neighbor cannot be found. Depending on the application,
the final node in a failed attempt may still forward the data to the
destination node if the destination is in transmission range.
4.1 CAD Trajectory Design
To present the most flexible and easy to use tool to the expert who is charged
with tracing the desired trajectory or map road, a CAD system with a virtual
road map of the environment where the sensors are deployed is considered.
The expert is asked to input a sequence of points in order (versus scattered)
as to where the nominal trajectory will follow. These ordered points can be
considered as data points to which a parameter set describing the trajectory
will be found by fitting a B-spline model to the data as in [26]. There are
many reasons why B-splines are attractive structures:
375
Fernand S. Cohen, Joshua Goldberg, and Jaudelice C. de Oliveira
??? Smoothness and continuity which allows any curve to consist of a concatenation
of curve segments, yet be treated as a single unit that can be
described at any desired resolution (infinite resolution);
??? Built-in boundedness, a property which is lacking in both the implicit or
explicit polynomial representation, whose zero set can shoot to infinity
[31].
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