Traffic signal preemption system
First Claim
1. A traffic signal preemption system for enabling emergency vehicles to cause a traffic light controller at an intersection to preempt traffic signals at the intersection in favor of emergency vehicles, said system comprising:
- a vehicle information transmission system installed in at least one emergency vehicle and including directional transmission means actuatable by the vehicle'"'"'s occupants for generating information identifying said at least one emergency vehicle and for repeatedly transmitting said information, encoded into repeatedly transmitted vehicle identification signals, in the direction of vehicular motion;
a vehicle detection, identification, and preemption system connecting to at least one traffic light controller, said detection, identification, and preemption system includingradio signal receiving means for receiving vehicle identification signals from said at least one emergency vehicle and for extracting information identifying the emergency vehicle therefrom, said radio receiving means including gain control means for producing a signal level signal indicative of the strength of said vehicle identification signals, andprocessing means for determining, based upon said received vehicle identification signals, said signal level signal, and preprogrammed preemption criteria including the identity of said at least one emergency vehicle, when and in favor of which direction and for how long to preempt an intersection, said processing means delaying preemption until a sufficient number of said received vehicle identification signals of sufficient signal level have been received in a brief enough time interval from any one given vehicle of said at least one emergency vehicle to indicate that said given vehicle is at the proper distance from the intersection for preemption to commence.
8 Assignments
0 Petitions
Accused Products
Abstract
When placed into operation by the occupants of an emergency vehicle, a vehicle transmission system having a directional antenna sends out a series of UHF messages spaced apart by varying lengths of time and identifying the emergency vehicle, its priority, and its direction, or indicating that the vehicle is travelling along a pre-planned route. At each signal-controlled intersection, a vehicle detection, identification, and preemption system having an omnidirectional antenna and containing information identifying vehicles authorized to preempt the intersection and their pre-planned directions of travel receives these messages from plural vehicles and determines when and in favor of which direction and for how long the intersection is to be preempted.
80 Citations
28 Claims
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1. A traffic signal preemption system for enabling emergency vehicles to cause a traffic light controller at an intersection to preempt traffic signals at the intersection in favor of emergency vehicles, said system comprising:
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a vehicle information transmission system installed in at least one emergency vehicle and including directional transmission means actuatable by the vehicle'"'"'s occupants for generating information identifying said at least one emergency vehicle and for repeatedly transmitting said information, encoded into repeatedly transmitted vehicle identification signals, in the direction of vehicular motion; a vehicle detection, identification, and preemption system connecting to at least one traffic light controller, said detection, identification, and preemption system including radio signal receiving means for receiving vehicle identification signals from said at least one emergency vehicle and for extracting information identifying the emergency vehicle therefrom, said radio receiving means including gain control means for producing a signal level signal indicative of the strength of said vehicle identification signals, and processing means for determining, based upon said received vehicle identification signals, said signal level signal, and preprogrammed preemption criteria including the identity of said at least one emergency vehicle, when and in favor of which direction and for how long to preempt an intersection, said processing means delaying preemption until a sufficient number of said received vehicle identification signals of sufficient signal level have been received in a brief enough time interval from any one given vehicle of said at least one emergency vehicle to indicate that said given vehicle is at the proper distance from the intersection for preemption to commence. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A traffic signal preemption system for enabling emergency vehicles to cause a traffic light controller at an intersection to preempt traffic signals at the intersection, causing them to signal green for an emergency vehicle and red for other directions, said system comprising:
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a vehicle information transmission system installed in said emergency vehicle and including directional transmission means actuatable by the vehicle'"'"'s occupants for generating information identifying said emergency vehicle and for repeatedly transmitting said information as a vehicle identification signal in the direction of vehicular motion at periodic intervals whose durations are varied to avoid frequent simultaneous generations and transmissions by plural emergency vehicles entering the same intersection; and a vehicle detection, identification, and preemption system connecting to said traffic light controller and including radio signal receiving means for receiving vehicle identification signals from one or more of said transmission systems, for extracting information identifying the emergency vehicle therefrom, and for determining, based upon preprogrammed preemption criteria including the identity of the vehicles, when and in favor of which direction and for how long to preempt an intersection; which traffic signal preemption system further includes portable control panel and central data base means for feeding information including vehicle identification information and transmit timeout information into said vehicle transmission system. - View Dependent Claims (17)
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18. A traffic signal preemption system for enabling emergency vehicles to cause a traffic light controller at an intersection to preempt traffic signals at the intersection, causing them to signal green for an emergency vehicle and red for other directions, said system comprising:
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a vehicle information transmission system installed in said emergency vehicle and including directional transmission means actuatable by the vehicle'"'"'s occupants for generating information identifying said emergency vehicle and for repeatedly transmitting said information as a vehicle identification signal in the direction of vehicular motion at periodic intervals whose durations are varied to avoid frequent simultaneous generations and transmissions by plural emergency vehicles entering the same intersection; and a vehicle detection, identification, and preemption system connecting to said traffic light controller and including radio signal receiving means for receiving vehicle identification signals from one or more of said transmission systems, for extracting information identifying the emergency vehicle therefrom, and for determining, based upon preprogrammed preemption criteria including the identity of the vehicles, when and in favor of which direction and for how long to preempt an intersection; said vehicle detection, identification, and preemption system further including lock out means for locking out preemptions in favor of a particular vehicle or direction for a predetermined time interval following a preemption in favor of that vehicle or direction to avoid accidental multiple successive preemptions in favor of the same vehicle.
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19. A traffic signal preemption system for enabling emergency vehicles to cause a traffic light controller at an intersection to preempt traffic signals at the intersection, causing them to signal green for an emergency vehicle and red for other directions, said system comprising:
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a vehicle information transmission system installed in said emergency vehicle and including directional transmission means actuatable by the vehicle'"'"'s occupants for generating information identifying said emergency vehicle and for repeatedly transmitting said information as a vehicle identification signal in the direction of vehicular motion at periodic intervals whose durations are varied to avoid frequent simultaneous generations and transmissions by plural emergency vehicles entering the same intersection, and a vehicle detection, identification, and preemption system connecting to said traffic light controller and including radio signal receiving means for receiving vehicle identification signals from one or more of said transmission systems, for extracting information identifying the emergency vehicle therefrom, and for determining, based upon preprogrammed preemption criteria including the identity of the vehicles, when and in favor of which direction and for how long to preempt an intersection; wherein said vehicle detection, identification, and preemption system must receive a predetermined number of vehicle identification signals from a given vehicle within a predetermined time interval before it will initiate a preemption in favor of that vehicle.
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20. A traffic signal preemption system for enabling emergency vehicles to cause a traffic light controller at an intersection to preempt traffic signals at the intersection, causing them to signal green for an emergency vehicle and red for other directions, said system comprising:
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a vehicle information transmission system installed in said emergency vehicle and including directional transmission means actuatable by the vehicle'"'"'s occupants for generating information identifying said emergency vehicle and for repeatedly transmitting said information as a vehicle identification signal in the direction of vehicular motion at periodic intervals whose durations are varied to avoid frequent simultaneous generations and transmission by plural emergency vehicles entering the same intersection; and a vehicle detection, identification, and preemption system connecting to said traffic light controller and including radio signal receiving means for receiving vehicle identification signals from one or more of said transmission systems, for extracting information identifying the emergency vehicle therefrom, and for determining, based upon preprogrammed preemption criteria including the identity of the vehicles, when and in favor of which direction and for how long to preempt an intersection; wherein said vehicle detection, identification, and preemption system must receive a predetermined number of vehicle identification signals of a predetermined minimum strength before it will initiate a preemption in favor of that vehicle.
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21. A traffic signal preemption system for enabling emergency vehicles to cause a traffic light controller at an intersection to preempt traffic signals at the intersection, said system comprising:
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a vehicle information transmission system installed in at least one emergency vehicle and including directional transmission means actuatable by the vehicle'"'"'s occupants for generating information identifying said emergency vehicle and for repeatedly transmitting said information as a vehicle identification signal in the direction of vehicular motion; a vehicle detection, identification, and preemption system connecting to at least one traffic light controller and including radio signal receiving means for receiving vehicle identification signals from one or more of said transmission systems, for extracting information identifying the emergency vehicle therefrom, and for determining, based upon preprogrammed preemption criteria including the identity of the vehicles, when and in favor of which direction and for how long to preempt an intersection; wherein said vehicle detection, identification, and preemption system contains intersection entry direction information for each of said at least one emergency vehicles, which information is stored within each said vehicle detection, identification, and preemption system; and wherein this intersection entry direction information enables said vehicle detection, identification, and preemption a system to determine the direction from which a given vehicle is approaching the intersection.
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22. A traffic signal preemption system for enabling emergency vehicles to cause a traffic light controller at an intersection to preempt traffic signals at the intersection, said system comprising:
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a vehicle information transmission system installed in said emergency vehicle and including directional transmission means actuatable by the vehicle'"'"'s occupants for generating information identifying said emergency vehicle and for repeatedly transmitting said information as a vehicle identification signal in the direction of vehicular motion, said directional transmission means including a transmitting antenna mounted upon said vehicle and transmitting radio signals beamed sufficiently in the direction of travel of said vehicle to minimize the likelihood of causing a preemption of an intersection to the side or rear of the vehicle; a vehicle detection, identification, and preemption system connecting to said traffic light controller, said detection, identification, and preemption system including radio signal receiving means for receiving vehicle identification signals from one or more of said transmission systems and for extracting information identifying the emergency vehicle therefrom, said radio receiving means including gain control means for producing a signal level signal indicative of the strength of said vehicle identification signals, and processing means for determining, based upon said received vehicle identification signals, said signal level signal, and preprogrammed preemption criteria including the identity of the vehicles, when and for how long to preempt an intersection. - View Dependent Claims (23, 24, 25, 26, 27, 28)
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Specification