Actuated digital pretimed traffic controller
AssigneeGulf & Western Manufacturing Company
InventorsFrank W. Hill, William L. May, Willard L. Kent
Life of this patent
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Abstract
In a digital pretimed traffic controller of the type used to control traffic signals at an intersection during a selected signal cycle there is provided an improvement wherein a demand signal, such as created by a detector, is directed to the controller. The demand signal is used for selecting one of a plurality of interval sequences within a fixed time cycle background. In this manner, the digital pretimed controller is compatible with electro-mechanical controllers and still retains traffic actuation versatility. The controller also is constructed to assure that the overall cycle length and the programmable individual interval times are identical before the particular timing plan can be accepted by the controller.
Claims11
In a digital pretimed traffic controller of the type used to control traffic signals at an intersection during a selected signal cycle, said controller including a central processing unit, a read only memory means for storing the executive program for said controller and a plurality of programmed solid state camshaft simulating signal plans each having a number of distinct intervals to be processed in sequence during a cycle of said controller, a random access read/write memory means for storing a rotary dial simulating timing plan having stored duration times for each of said distinct intervals of each of said signal plans stored in said read only memory means, external cycle select means for activating one of said signal plans and one of said timing plans for processing by said controller in accordance with said stored executive program, and interfacing means for controlling the condition of said traffic signals in accordance with the selected cycle being processed by said controller, the improvement comprising:
- detector means for directing a demand signal to said controller, means for providing a plurality of different interval sequences in a selected portion of the selected cycle being processed and means for selecting one of said interval sequences in response to said demand signal.
In a digital pretimed traffic controller of the type used to control traffic signals at an intersection during a signal cycle, said controller including a central processing unit, a read only memory means for storing the executive program for said controller and a plurality of programmed solid state camshaft simulating signal plans each having a number of distinct intervals to be processed in sequence during a cycle of said controller, a random access read/write memory means for storing a rotary dial simulating timing plan having stored duration times for each of said distinct intervals of each of said signal plans stored in said read only memory means, external cycle select means for activating one of said signal plans and one of said timing plans for processing by said controller in accordance with said stored executive program, and interfacing means for controlling the condition of said traffic signals in accordance with the selected cycle being processed by said controller, the improvement comprising:
- means for adjusting the cycle length time of a selected cycle, means for individually setting the time duration of each individual interval in said selected cycle and means for preventing processing of said selected cycle if said cycle length is different in time from the summation of the duration of said intervals of said selected cycle.
In a digital pretimed traffic controller of the type having a central processing unit, a read only memory means for storing the executive program for said controller and a plurality of programmed solid state camshaft simulating signal plans each having a number of distinct intervals to be processed in sequence during a cycle of said controller, a random access read/write memory means for storing a rotary dial simulating timing plan having stored duration times for each of said distinct intervals of each of said signal plans stored in said read only memory means, external cycle select means for activating one of said signal plans and one of said timing plans for processing by said controller in accordance with said stored executive program, and interfacing means for controlling the condition of said traffic signals in accordance with the selected cycle being processed by said controller, the improvement comprising:
- a means for storing a digital interval advance signal;
- first converting means for converting said digital advance signal into an alternating current advance signal;
- conductor means external of said controller for directing said alternating current advance signal to a manually operating switch having an automatic interval advance position;
- second converting means for converting said alternating current advance signal into a digital advance signal for use by said controller;
- and means for directing said alternating current advance signal from said first converting means to said second converting means when said switch is shifted into said automatic interval advance position.
Dependencies are inferred from the claim text.