System for controlling unmanned vehicles at intersections

Abstract

A transportation system has several guide strips for unmanned vehicles. The guide strips define an intersection, and a mark warning of the intersection is disposed adjacent each guide strip before the intersection. Each of the vehicles has a detector for the respective mark, a signal transmitter, a receiver for signals coming from the other vehicles, and a timer for measuring a timed interval shorter than the time required to travel from the respective mark to the intersection. The transmitters and timers begin to operate in response to detection of the respective marks. After a selected vehicle passes the respective mark, its receiver attempts to pick up signals from the other vehicles. If no other vehicles are detected before the selected vehicle reaches the intersection, the selected vehicle passes through the intersection without stopping. On the other hand, should the selected vehicle detect another vehicle before the respective timed interval ends, the selected vehicle comes to a halt upstream of the intersection, and stops transmitting, when the timed interval is up. The selected vehicle remains stationary for a predetermined stopping interval following which it begins to move and transmit again if it no longer detects another vehicle. To prevent collisions at the intersection, the timed intervals and stopping intervals differ from vehicle to vehicle.