Patent GB-1199603-A (GB)
Title: Programming of Flow Path Routes
IPC: G08G5/06
Filed: 1967-05-15
Abstract: 1,199,603. Programming vehicle paths. E. W. BLISS CO. 15 May, 1967 [20 May, 1966], No. 22450/67. Heading G4Q. For programming the passage of movable means along a predetermined path having intersection points, an operator moves a stylus along a display panel which contains a map of the route in the form of grooves having continuous non-conductive side walls, whereby means are successively actuated by the stylus to control signals or routing means at the intersections which occur along the actual path. The invention is described in connection with routing aircraft on an airfield to or from the runways, but may also be applied to routing cars on roads, railway trains through track intersections, or materials such as fluids through a network of intersecting flow paths. As applied to controlling aircraft, the display panel (Fig. 2) comprises a map of the airfield in which the aircraft paths are represented by grooves 306 in a top opaque sheet through which a translucent lower sheet (302 in Fig. 3, not shown) is there visible. Beneath the panel are a number of magnetic reed relays (e.g. PES, PS1) which are closed when a magnetic stylus is moved by the operator along the predetermined path, and these result in appropriate direction signals being illuminated at the actual intersections on the airfield (Fig. 8, not shown). At the same time repeater lights (e.g. PL, DL) under the display panel show the path set up by the operator. The magnetic relays may be replaced by switches sensitive to pressure, heat, light, sound or capacitance. The airfield direction signals are as in Specification 1,199,601 and when not energized show a black background. Selected lamps can be lit in each signal to display a yellow arrow pointing in a desired direction, or red lamps can be lit as a stop indication. A yellow vertical arrow can also be displayed to the rear of each signal. The display panel also contains lights energized by the presence of an aircraft on selected parts of the airfield, operated e.g. by current-carrying loops, ultrasonic detectors or treadle pads. The panel lights are constructed as in Specification 1,199,604. Fig. 11 is a block diagram of the electrical connections necessary to produce these functions, and Figs. 12-12J (not shown) contain the detailed circuitry of the electromagnetic relays and logic circuitry used; these may be repaced by solidstate relays and logic. Operation.-Assuming that an aircraft is to approach intersection C (Fig. 2) from the west and to leave it by the south path, the operator moves his stylus accordingly along the groove in the display panel. In the west path relay PES erases any previous programme set up and relay PS1 de-energizes the red stop light in the west path and lights repeater PLE. Relay PS2 in the south path energizes the direction signals in the west and south paths and lights repeater PLL. Although the stylus passes over the erase relay PES in the south path, a capacitor delay circuit prevents this from operating if the PS1 relay has only just been energized. When the aircraft moves towards the intersection a detector energizes the light DLI in the west path on the display panel. At the intersection the aircraft operates another detector to extinguish light DLI and energize light DLC at the centre of the intersection to show that this is now occupied. As the aircraft turns into the south path a further detector extinguishes light DLC and energizes light DLO in the south path. As the aircraft proceeds further into the south path a fourth detector extinguishes light DLO. If an aircraft should approach an intersection in the course of another manoeuvre the light DLI can be extinguished by the operator passing his stylus over an erase relay DES which is offset so that it is not operated when the stylus is moved along the groove. This cancellation is effective only after a reset button (not shown) is pressed, to avoid accidental erasure. If an aircraft should leave the intersection without operating the detectors in an exit path the light DLC can be extinguished by the operator pressing a further button; this also erases the programme. First alarm.-If an aircraft overruns a red stop light an alarm light AL flashes on the display panel by the operation of the second detector. A buzzler also sounds and all the signals at the intersection go red. The operator then cancels the alarm by a button and reprogrammes the path. Second alarm.-If an aircraft leaves an intersection by the wrong path, the detectors in its exit path are operated, the alarm light AL and buzzer are sounded and the signals go red. The operator then communicates with the aircraft by radio. Third alarm.-If the operator programmes an aircraft to leave by the south exit at the same time as another aircraft is approaching along this path, the alarm lamp and buzzer are again energized and the intersection signals go red. A similar result occurs if the operator attempts to set up conflicting programmes.