Digital traffic control system
First Claim
1. An improved digital control system for controlling the flow of traffic in selected directions in response to digital signals selectively transmitted from a common transmitting control unit to multiple separate receiving traffic control units respectively associated with each controlled direction, the improvements comprising:
- (A) in the transmitting unit, a transmitter, a modulator, a digital command code generator operative when actuated to generate a character specific for each different receiving unit, and a command selector operative to select for delivery through said modulator to said transmitter a selected one of said command codes to be radiated as a digital signal;
(B) in each of said receiving traffic control units in the system;
(a) traffic control indication means operative in different modes to display to traffic flowing in a direction to be controlled multiple diverse traffic control indications;
(b) a receiver;
a digital signal demodulator connected thereto and operative to deliver demodulated characters transmitted by the system'"'"'s transmitting unit;
a microprocessor;
read only memory (ROM) means operative to program the microprocessor to process demodulated characters to produce variable indicating the operating mode of the traffic control indication means in said receiving traffic control unit and the operating mode of any of said receiving traffic control units in the system which is remote with respect thereto;
random access memory (RAM) means coupled to the microprocessor and operative to receive and store said variables in tables which are specific to each of said receiving traffic control units and which represent the current operating mode of each of said receiving traffic control unit'"'"'s traffic control indication means, the ROM means programming the microprocessor on each successive pass through the program to produce and store variable for a different one of said receiving traffic control units in the system, and the ROM means programming the microprocessor incident to processing variables for each of said receiving traffic control units to compare variables thereof to avoid conflicting modes of traffic control indications and then to deliver appropriate binary control outputs, and(c) said traffic control indication means being operative in response to said binary control outputs to display traffic control indications as determined by the receiving traffic control unit'"'"'s variables.
1 Assignment
0 Petitions
Accused Products
Abstract
A digital control system for controlling the flow of traffic in selected directions in response to digital signals transmitted from a common transmitting control unit to multiple separate receiving traffic control units respectively associated with each controlled direction. The transmitting unit includes a transmitter and digital command code generator operative when actuated to transmit a character in the form of a digital signal specific for one of the receiving units. Each receiving unit includes traffic control indicators operative in different modes of display indications visible to traffic flowing in the direction to be controlled by that unit. Each receiving unit further includes a receiver operative to deliver demodulated characters based on codes transmitted by the transmitting unit, and the codes controlling a microprocessor programmed to process the received characters to initiate command outputs, and logic circuitry connected to receive said outputs and responsive thereto to display traffic control indications as determined by the local unit'"'"'s demodulated characters, each unit keeping a model of what is being displayed by other units in the system and using it to prevent conflicting traffic control indications.
52 Citations
35 Claims
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1. An improved digital control system for controlling the flow of traffic in selected directions in response to digital signals selectively transmitted from a common transmitting control unit to multiple separate receiving traffic control units respectively associated with each controlled direction, the improvements comprising:
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(A) in the transmitting unit, a transmitter, a modulator, a digital command code generator operative when actuated to generate a character specific for each different receiving unit, and a command selector operative to select for delivery through said modulator to said transmitter a selected one of said command codes to be radiated as a digital signal; (B) in each of said receiving traffic control units in the system; (a) traffic control indication means operative in different modes to display to traffic flowing in a direction to be controlled multiple diverse traffic control indications; (b) a receiver;
a digital signal demodulator connected thereto and operative to deliver demodulated characters transmitted by the system'"'"'s transmitting unit;
a microprocessor;
read only memory (ROM) means operative to program the microprocessor to process demodulated characters to produce variable indicating the operating mode of the traffic control indication means in said receiving traffic control unit and the operating mode of any of said receiving traffic control units in the system which is remote with respect thereto;
random access memory (RAM) means coupled to the microprocessor and operative to receive and store said variables in tables which are specific to each of said receiving traffic control units and which represent the current operating mode of each of said receiving traffic control unit'"'"'s traffic control indication means, the ROM means programming the microprocessor on each successive pass through the program to produce and store variable for a different one of said receiving traffic control units in the system, and the ROM means programming the microprocessor incident to processing variables for each of said receiving traffic control units to compare variables thereof to avoid conflicting modes of traffic control indications and then to deliver appropriate binary control outputs, and(c) said traffic control indication means being operative in response to said binary control outputs to display traffic control indications as determined by the receiving traffic control unit'"'"'s variables. - View Dependent Claims (2, 3, 4)
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5. An improved digital control system for controlling the flow of traffic in selected directions in response to digital signals selectively transmitted from a common transmitting control unit to multiple separate receiving traffic control units respectively associated with each controlled direction, the improvements comprising:
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(A) in the transmitting unit, a transmitter, a modulator, a digital command code generator operative when actuated to generate a character specific for each different receiving unit, and a command selector operative to select for delivery through said modulator to said transmitter a selected one of said command codes to be radiated as a digital signal; (B) in each of said receiving traffic control units in the system; (a) traffic control indication means operative in different modes to display to traffic flowing in a direction to be controlled multiple diverse traffic control indications; (b) a receiver;
a digital signal demodulator connected thereto and operative to deliver demodulated characters transmitted by the system'"'"'s transmitting unit;
a microprocessor;
read only memory (ROM) means operative to program the microprocessor to process demodulated characters to produce variable indicating the operating mode of the traffic control indication means in said receiving traffic control unit and the operating mode of any of said receiving traffic control units in the system which is remote with respect thereto;
random access memory (RAM) means coupled to the microprocessor and operative to receive and store said variables in tables which are specific to each of said receiving traffic control units and which represent the current operating mode of each of said receiving traffic control unit'"'"'s traffic control indication means, the ROM means programming the microprocessor on each successive pass through the program to produce and store variable for a different one of said receiving traffic control units in the system, and the ROM means programming the microprocessor incident to processing variable for each of said receiving traffic control units to compare variables thereof to avoid conflicting modes of traffic control indications and then to deliver appropriate binary control outputs,(c) said traffic control indication means being operative in response to said binary control outputs to display traffic control indications as determined by the of each of said receiving traffic control unit'"'"'s variables and (d) including microprocessor clocking means and wherein the traffic control indication means further includes a STOP, GO and CAUTION mode indications, said ROM means being further operative to program the microprocessor after the loss of a command code character specific to each individual receiving traffic control unit automatically to step the control outputs of the microprocessor to change from an existing GO mode indication to a CAUTION mode indication and the to a STOP mode indication, respectively, after predetermined dwell intervals timed by said clocking means, the STOP mode indication remaining until a command code character specific to an individual receiving traffic control unit is again received and demodulated. - View Dependent Claims (6, 7, 8, 9, 10)
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11. An improved digital control system for controlling the flow of traffic in selected directions in response to digital signals selectively transmitted from a common transmitting control unit to multiple separate receiving traffic control units respectively associated with each controlled direction, the improvements comprising:
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(A) in the transmitting unit, a transmitter, a modulator, a digital command code generator operative when actuated to generate a character specific for each different receiving unit;
a command selector operative to select for delivery through said modulator to said transmitter a selected one of said command codes to be radiated as a digital signal; and
system address code means for generating and delivering to the transmitter digital address signals specific to this control system;(B) in each receiving traffic control unit in the system; (a) traffic control indication means operative in different modes to display to traffic flowing in a direction to be controlled multiple diverse traffic control indications; and (b) a receiver;
a digital signal demodulator connected thereto and operative to deliver demodulated characters and address signals transmitted by the system'"'"'s transmitting unit;
local system address means including comparator means for comparing the local address means with received address signals and delivering a VALID signal when they match;
a microprocessor;
read only memory (ROM) means operative to program the microprocessor to process demodulated characters to produce variables indicating the operating mode of the traffic control indication means;
random access memory (RAM) means coupled to the microprocessor and operative in the presence of a VALID signals to receive and store said variables which represent the current operating mode of other receiving traffic control units, the ROM means programming the microprocessor on successive passes through the program to produce and store said variable, and the ROM means programming the microprocessor to deliver appropriate binary control outputs,(c) said traffic control indication means being operative in response to said binary control outputs to display traffic control indications as determined by the receiving traffic control unit'"'"'s variables and being automatically responsive to display a predetermined one of said traffic control indications upon the loss of a command code. - View Dependent Claims (12, 13, 14, 15, 16)
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17. The method of controlling the flow of traffic in selected directions in response to signals selectively transmitted within a system from a common transmitting control unit to multiple separate receiving units having traffic control indication means which include GO and STOP indications respectively associated with each controlled traffic direction, including the following steps:
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(a) transmitting signals which at any moment in time may include a code specific for a selected one of the receiving units; (b) receiving the signals at the receiving units and recovering the currently transmitted code therefrom; (c) processing the recovered codes to obtain at each of the receiving units multiple variables respectively indicative of the present mode of display of the traffic control indication means in each of the receiving units of the system; (d) comparing the variables of each of the receiving units and commanding a traffic control indication at each of the receiving units which is not in conflict with the mode of any other receiving unit, and (e) controlling the traffic control indication means at all the receiving units so that such traffic control indication means will go to a STOP indication automatically upon the failure of any of the receiving units to properly receive specific codes. - View Dependent Claims (18, 19, 20)
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21. An improved digital control system for controlling the flow of traffic in selected directions in response to digital signals selectively transmitted from a common transmitting control unit to multiple separate receiving traffic control units respectively associated with each controlled direction, the improvements comprising:
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(A) in the transmitting unit, a transmitter, a modulator, a digital command code generator operative when actuated to generate a command character specific for each different receiving unit, and a command selector operative to select for delivery through said modulator to said transmitter a selected one of said command codes to be radiated as a digital signal; (B) in each receiving traffic control unit in the system; (a) traffic control indication means operative in different modes to display to traffic flowing in a direction to be controlled multiple diverse traffic control indications including a STOP mode indication; and (b) a receiver;
a digital signal demodulator connected thereto and operative to deliver demodulated characters based on codes transmitted by the system'"'"'s transmitting unit;
a microprocessor;
read only memory (ROM) means operative to program the microprocessor to process demodulated characters to produce binary command outputs, and logic means connected to receive said binary command outputs, and logic means connected to receive said binary outputs and responsive thereto to deliver control outputs,(c) said traffic control indication means being operative in response to said control outputs to display traffic control indications as determined by the receiving traffic control unit'"'"'s demodulated characters, and (d) means for controlling said traffic control indication means to automatically be operative to reflect STOP mode upon the loss of a command character to the receiving traffic control unit. - View Dependent Claims (22, 23, 24, 25)
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26. An improved digital control system for controlling the flow of traffic in selected directions in response to digital signals selectively transmitted from a common transmitting control unit to multiple separate receiving traffic control units respectively associated with each controlled direction, the improvements comprising:
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(A) in the transmitting unit, a transmitter, a modulator, a digital command code generator operative when actuated to generate a command character specific for each different receiving unit, and a command selector operative to select for delivery through said modulator to said transmitter a selected one of said command codes to be radiated as a digital signal; (B) in each receiving traffic control unit in the system; (a) traffic control indication means operative in different modes to display to traffic flowing in a direction to controlled multiple diverse traffic control indications; and (b) a receiver;
a digital signal demodulator connected thereto and operative to deliver demodulated characters based on codes transmitted by the system'"'"'s transmitting unit;
a microprocessor;
read only memory (ROM) means operative to program the microprocessor to process demodulated characters to produce binary command outputs, and logic means connected to receive said binary command outputs, and logic means connected to receive said binary outputs and responsive thereto deliver control outputs,(c) said traffic control indication means being operative in response to said control outputs to display traffic control indications as determined by the unit'"'"'s demodulated characters, and (d) each receiving traffic control unit further includes microprocessor clocking means and wherein the traffic control indication means further includes a STOP, GO and CAUTION mode indications, said ROM means being further operative to program the microprocessor after the loss of a command character specific to a given receiving traffic control unit automatically to step the control outputs of the microprocessor to change from an existing GO mode indication to a CAUTION mode indication and then to a STOP mode indication, respectively after predetermined dwell intervals timed by said clocking means, the STOP mode indication remaining until a command character specific to that unit is again received and demodulated. - View Dependent Claims (27, 28, 29, 30, 31)
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32. The method of controlling the flow of traffic in selected directions in response to signals selectively transmitted from a common transmitting control unit to multiple separate receiving units having traffic control GO and STOP indication modes respectively associated with each controlled traffic direction, including the following steps:
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(a) transmitting signals which at any moment in time may include a code specific for a selected one of the receiving units; (b) receiving the signals at the receiving units and recovering the currently transmitted code therefrom; (c) processing the recovered code at each of the units to obtain at the receiving units to which a code is specific a command which persists as long as the code is being received; (d) initiating a receiving unit to the GO mode so long as the code persists, while returning the other units to STOP mode, and (e) changing each receiving unit to the STOP mode upon loss of any received code at all. - View Dependent Claims (33, 34)
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35. A portable traffic control system for controlling the flow of vehicular traffic in selected directions comprising a transmitting control unit for selectively transmitting signals within the system, at least two separate and space receiving units having traffic control indication means which include GO and STOP indications, said transmitting unit including a transmitter having a command code generator operative when acuated to generate a signal character specific for each of said receiving units;
- a command selector operative to select for delivery a selected one of said command codes to be radiated as a signal, and system address code means for generating and delivering to the transmitter address signals specific to the control system, each of said receiving units having a receiver, a signal demodulator connected to said receiver and operative to deliver demodulated characters and address signals transmitted to said receiver, a local system address means including comparator means for comparing the local address means with received address signals and delivering a VALID signals when they match;
means operative to process demodulated signal characters to produce variables indicating the operating mode of the traffic control indication means;
means operative in the presence of a VALID signal to receive and store variables which represent the current operating mode of other receiving units, said traffic control indication means being operative in response to said variables received by the receiving unit, and said traffic control indication means being automatically responsive to display a STOP indication upon the failure of said receiving units to properly receive signal characters from said transmitter or upon a conflict with the variables of other receiving units in the system.
- a command selector operative to select for delivery a selected one of said command codes to be radiated as a signal, and system address code means for generating and delivering to the transmitter address signals specific to the control system, each of said receiving units having a receiver, a signal demodulator connected to said receiver and operative to deliver demodulated characters and address signals transmitted to said receiver, a local system address means including comparator means for comparing the local address means with received address signals and delivering a VALID signals when they match;
Specification