TRANSIT MONITORING SYSTEM

• US 3,771,119 A
• Filed: 06/22/1972
• Issued: 11/06/1973
• Est. Priority Date: 06/22/1972
• Status: Expired due to Term

• Current Assignee: Robert R. Evans
• Original Assignee: Robert R. Evans
• Inventors: Evans, Robert R.
• Primary Examiner(s): Marbert, James B.
• Assistant Examiner(s): Libman, George H.
• Application Number:
  US05/265,344
• Time in Patent Office: 502 Days
• Field of Search: 246/122R 340/23,24,268
• US Class Current: 340/988
• CPC Class Codes: B61L 25/026 Relative localisation, e.g. using odometer
• CPC Class Codes: B61L 3/225 using separate conductors along the route
• CPC Class Codes: G08G 1/0104 Measuring and analyzing of parameters relative to traffic conditions
• CPC Class Codes: G08G 1/127 to a central station ; Indicators in a central station

Abstract

Vehicles with beacon transmitters are detected by wayside antennas. Code operated switches selectively connect antennas to receivers which indicate vehicle occupancy of associated increments of way. Stored vehicle data is serially shifted to a processor unit.

Claims

1. In a transportation system in which vehicles normally occupy only definite spaced virtual slots moving in synchronized fashion along a way, a method for monitoring the position of vehicles moving along a sector of way comprising the steps of dividing said sector of way into segments, dividing each of said segments into a plurality of increments of way, the number of increments in every segment being the same, periodically synchronously sensing all and only increments in said sector then occupied by slots to obtain data indicative of vehicle occupancy in said sensed increment in each segment, maintaining a current record of said segments programmed for occupancy by vehicles, comparing said obtained vehicle occupancy data with said current record, and providing an indication of discrepancies between actual and programmed occupancy.

2. The method as claimed in claim 1 including the steps of storing said obtained data as obtained, in a plurality of registers associated respectively with each segment, and sequentially shifting said stored data from one said register to another and finally to a processing station wherein said record is maintained.

3. The method as claimed in claim 1 including the steps of emitting a signal from all vehicles traversing said segment, sensing said signal to obtain said data.

4. In a transportation system in which vehicles normally occupy only definite spaced virtual slots moving in synchronized fashion along a way, apparatus for monitoring the position of vehicles passing on a sector of said way comprising a sector processing unit for storing information about the occupancy programmed for said sector and for comparing such information with information on the actual occupancy of said sector, said sector processor having an input for receiving data about the occupancy of said sector and a plurality of local processing units connected to the input of said sector processor, said local units being associated one-to-one with successive, contiguous segments dividing said sector, said segments being each as long as the spacing between successive slots, each of said local units including a plurality of sensors responsive to occupancy by a vehicle of a distinct increment of way along the associated segment, said sensors being ordered to correspond with the progress of a vehicle along said associated segment, a plurality of sensor selector switches associated one-to-one with said sensors, each switch having a data input connected with the associated sensor, an ordinality input, and an output, each of said switches being responsive to an ordinality signal applied to its said ordinality input to selectively connect to said switch output a sensor of ordinality designated by said ordinality signal, a receiver having an input connected to a plurality of said switch outputs and an output, said receiver operative to discriminate a signal on its said input and produce on its said output a quantized signal indicative of activation of said connected sensor.

5. The apparatus of claim 4 wherein each of said local processing units includes a storage register having a data input connected to said output of the receiver of the local unit, an output and a gating input, and is responsive to a signal applied to said gating input to admit and store a signal applied to its data input, all of said storage registers associated with said sector being serially interconnected as elements of a shift register having an output connected to said sector unit input.

6. Apparatus as claimed in claim 4, including onboard transmitters affixed to said vehicles and wherein said sensors include loop antennas installed along said way.

7. Apparatus for monitoring vehicles on a transit way comprisiNg a series of sensors disposed along said way, each said sensor being adapted to produce a data output in response to occupancy by a vehicle of a distinct increment of said way associated with a corresponding sensor, a plurality of sensor selectors associated one-to-one with said series of sensors, each of said selectors having an indexing input operative to enable its associated sensor to produce a data output when and only when a signal of predetermined value indexing the associated sensor is applied to said indexing input and a vehicle is occupying the associated increment of way, the indexing signal being a function of desired which performance a receiver coupled to a series of sensors, said receiver adapted to produce a qualified output signal indicative of stimulation of the then indexed sensor in response to a sensor data output and means for applying an indexing signal to said indexing inputs of said selectors.

8. Apparatus as claimed in claim 7 including a plurality of beacon transmitters, one on each of said vehicles, said sensors including wayside antennas for stimulation by said beacon transmitters.

9. Apparatus as claimed in claim 8 wherein said antennas are mounted on a curb of said way.

10. The apparatus as claimed in claim 7 wherein each said selector includes a switch connected between its associated sensor and said receiver, and said receiver includes a threshold detector and a storage circuit for storing said output signal.

11. The apparatus as claimed in claim 10 wherein said output signal is bipolar and indicates the presence or absence of a vehicle as detected by the indexed sensor, and said storage circuit is a bistable storage device.

12. The apparatus as claimed in claim 7 wherein said sensors are arranged in a plurality of sector groups, and further including a plurality of receivers and a sector processor associated with each said sector group, each said sector processor including timing and control means for generating selector indexing signals and sensing signals for sensing the output signals produced by said associated receivers.

13. The apparatus as claimed in claim 12 wherein said sector processor includes storage means and means responsive to said sensing signal for serially transferring said receiver output signals to said storage means.

14. The apparatus as claimed in claim 13 and further including a system controller including means for generating programmed vehicle data and wherein said sector controller includes means for comparing said programmed vehicle data with receiver output signals stored in said storage means.

15. The apparatus as claimed in claim 14 wherein each said vehicle includes a transmitter for transmitting an RF signal and each said sensor includes an elongated wayside antenna, each said antenna defining an increment of said way.

16. The apparatus as claimed in claim 15 wherein each said receiver includes a threshold detector responsive to the selected sensor antenna and a bistate storage circuit, and said sector processor timing and control means includes means for generating a series of shift signals to serially transmit data stored in said storage circuits to said storage means for comparison with said programmed vehicle data, and said comparing means including means for generating a discrepancy signal.