A navigational control system for altering movement activity of a robotic device
operating in a defined working area, comprising a transmitting subsystem integrated
in combination with the robotic device, for emitting a number of directed beams,
each directed beam having a predetermined emission pattern, and a receiving subsystem
functioning as a base station that includes a navigation control algorithm that
defines a predetermined triggering event for the navigational control system and
a set of detection units positioned within the defined working area in a known
spaced-apart relationship, the set of detection units being configured and operative
to detect one or more of the directed beams emitted by the transmitting system;
and wherein the receiving subsystem is configured and operative to process the
one or more detected directed beams under the control of the navigational control
algorithm to determine whether the predetermined triggering event has occurred,
and, if the predetermined triggering event has occurred transmit a control signal
to the robotic device, wherein reception of the control signal by the robotic device
causes the robotic device to implement a prescribed conduct that alters the movement
activity of the robotic device.