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.