Next: Track Extension Associations
Up: 18.4 Multitarget Tracking
Previous: Track Initialization
Unlike the two-dimensional tracking module, the three-dimensional
stereo tracker attempts to construct a single track for each
(perceived) underlying target. The fundamental algorithm element for
this type of tracking is the optimal associator described in
Section 18.4.2. A single pass through the three-dimensional
tracker utilizes optimal associations for two distinct subtasks:
As was noted in Section 18.4.2, a canonical problem with optimal
associators is the possibility of globally poor associations due to
incompatible lists or poor distance information for some of the entries in
either lists. These problems are addressed as follows:
- Track extensions
- Data from a sensor are associated with
predicted data positions for existing three-dimensional tracks. This
task is performed twice per scan, once for each two-dimensional
subsystem of Figure 18.17.
- Track initiation
- Two-dimensional report lists are associated
and new three-dimensional tracks are initiated for correlations to data
points not used in the preceding track extension step.
The associators for track extensions and initiations and the quality control
modules are described in the following subsections.
- Evaluations of individual distances for the cost matrix include
relatively restrictive cuts which prohibit poor associations. The nominal
cost for such associations is set to an ``infinite'' token and the association
is simply ignored if selected in the course of minimization of
- Additional ``quality control'' modules are used to assess feasibility of
proposed associations; tracks failing the quality constraints are deleted
from the system.
Wed Mar 1 10:19:35 EST 1995