Page 198 - Designing Autonomous Mobile Robots : Inside the Mindo f an Intellegent Machine

Sensors, Navigation Agents and Arbitration

Figure 12.7 demonstrates yet another variation that attempts to improve on the weak-
nesses of the ring. In this staggered ring configuration, transducers are mounted in a
zigzag pattern so that their beam patterns close the gaps that plague the earlier examples.
This same pattern can be duplicated at two levels as was done with the straight rings
in the previous configuration. This configuration provides better coverage in the plan
view, but at the expense of having even more transducers to fire.
Staggered configurations may increase the number of transducers per a half-ring from 13
to 16 (as in Figure 12.7) or even to 25, depending on the overlap desired. By this
point, we can see that getting good collision avoidance coverage with a ring configu-
ration is a bit like trying to nail jelly to a tree. Everything we do makes the problem
worse somewhere else.

Figure 12.7. Staggered-beam configuration

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