Traffic control system
First Claim
1. A traffic control system comprising a central station, a plurality of local stations each disposed for energizing traffic signals in a prescribed pattern to control traffic by performing control operations, and a multiplex communication system connecting said central station with each of said local stations for establishing communication from said central station to said local stations under control of said central station said multiplex system including means at said central station for generating a plurality of words having a fixed time relationship to one another, with a number of successive word positions constituting a frame and with each of said words being divided into time spaced portions each disposed for the transmission of an information element, the first of said elements in each word being a marker element and subsequent elements being data elements, said multiplex system including means at each of said local stations for selecting a word having a particular word position within each frame in response to the receipt of a marker element in that word position from said generating means, said selecting means including means for sensing the presence of a data element in the selected word and for generating a signal in response thereto containing information corresponding to a control operation of said local stations, each of said local stations includes circuit means for performing a specified control operation related to the energization of the traffic signals, and means connecting said signal from said sensing means to said circuit means to establish said specification control operation thereof.
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Accused Products
Abstract
A traffic control system which controls the timing of a plurality of traffic lights at a plurality of intersections with a variety of timing patterns, this invention contemplates utilizing modules which will operate automatically to control the flow of traffic and which also is readily controlled by a master controller for changing traffic flow cycles. The controller which is placed at the intersection is preset or programmed to establish a basic timing cycle. This timing cycle can be changed by the transmission of signals from a master controller and the storage of the signals at the intersection. A single master controller can thereby control a plurality of intersection controllers to vary the traffic flow over a wide area. By using multiplexing techniques, a single pair of signal wires can connect the master and a large number of independent intersection controllers. The individual controllers are designed to accept a plurality of standard plug-in components which are interconnected by a single component. Each of the standard components provides a choice of such things as basic timing cycles by the simple procedure of external switch plugs which can be changed simply, with few tools, in suit. In this manner, once the system is installed, changes in the traffic flow can be compensated by simple changes in the intersection controllers.
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Citations
35 Claims
- 1. A traffic control system comprising a central station, a plurality of local stations each disposed for energizing traffic signals in a prescribed pattern to control traffic by performing control operations, and a multiplex communication system connecting said central station with each of said local stations for establishing communication from said central station to said local stations under control of said central station said multiplex system including means at said central station for generating a plurality of words having a fixed time relationship to one another, with a number of successive word positions constituting a frame and with each of said words being divided into time spaced portions each disposed for the transmission of an information element, the first of said elements in each word being a marker element and subsequent elements being data elements, said multiplex system including means at each of said local stations for selecting a word having a particular word position within each frame in response to the receipt of a marker element in that word position from said generating means, said selecting means including means for sensing the presence of a data element in the selected word and for generating a signal in response thereto containing information corresponding to a control operation of said local stations, each of said local stations includes circuit means for performing a specified control operation related to the energization of the traffic signals, and means connecting said signal from said sensing means to said circuit means to establish said specification control operation thereof.
Specification