  Suppose in a given planar region, there are smart mobile evaders and we want
to detect them using sweeping agents. We assume that the agents have line
sensors of equal length. We propose procedures for designing cooperative
sweeping processes that ensure successful completion of the task, thereby
deriving conditions on the sweeping velocity of the agents and their paths.
Successful completion of the task means that evaders with a known limit on
their velocity cannot escape the sweeping agents. A simpler task for the
sweeping swarm is the confinement of the evaders to their initial domain. The
feasibility of completing these tasks depends on geometric and dynamic
constraints that impose a lower bound on the velocity the sweeping agent must
have. This critical velocity is derived to ensure the satisfaction of the
confinement task. Increasing the velocity above the lower bound enables the
agents to complete the search task as well. We present a quantitative and
qualitative comparison analysis between the total search time of same-direction
sweep processes and pincer-movement search strategies. We evaluate the
different strategies by using two metrics, total search time and the minimal
critical velocity required for a successful search. We compare two types of
pincer-movement search processes, circular and spiral, with their
same-direction counterparts, for any even number of sweeping agents. We prove
that pincer based strategies provide superior results for all practical
scenarios and that the spiral pincer sweep process allows detection of all
evaders while sweeping at nearly theoretically optimal velocities.
