Communications: electrical – Vehicle detectors
Reexamination Certificate
1999-11-22
2001-08-28
Wu, Daniel J. (Department: 2736)
Communications: electrical
Vehicle detectors
C340S937000, C340S916000, C340S921000, C701S301000
Reexamination Certificate
active
06281808
ABSTRACT:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
N/A
BACKGROUND OF THE INVENTION
The present invention relates generally to automated systems for traffic light control, and more specifically to a system employing one or more video recording cameras to predict red light violations and to control the current light phase of a traffic signal in response to predicted red light violations involving traffic travelling in an intersecting direction.
Contemporary road layouts involve large numbers of traffic signals used to control intersecting traffic flows. A typical traffic signal includes at least red and green phases; the red phase requires approaching traffic to stop before entering the intersection, and the green phase permits approaching traffic to pass through the intersection. A yellow phase is sometimes also used to provide advance notice of an upcoming red light phase.
For a variety of reasons, vehicles sometimes pass illegally through red lights. This may occur due to driver inattention, attempting to “beat” the light by speeding up while approaching a signal in a yellow light phase, or other precipitating circumstances. When a vehicle passes illegally through a red light, other vehicles within a traffic flow intersecting the path of the violating vehicle may be at risk of being struck by the violating vehicle. In such circumstances, these other vehicles may be forced to maneuver suddenly to avoid the violating vehicle. Such rapid maneuvering often results in further accidents occurring.
The costs associated with red light violations in terms of property damage, personal injuries, and deaths is unacceptably large. However, current traffic light control systems operate using light phase cycles that are not responsive to current traffic conditions, and include no mechanism to prevent cross traffic from entering an intersection when a red light violation is occurring or is about to occur in response to current traffic conditions.
It would therefore be desirable to have an automated traffic light control system which prevents traffic from entering an intersection when a red light violation is occurring or is about to occur. The system should enable vehicle operators to avoid travelling into an intersection by way of a conveniently understandable mechanism. The system should not otherwise interfere with traffic flows approaching or passing through the intersection.
BRIEF SUMMARY OF THE INVENTION
A system for collision avoidance at a traffic intersection having traffic signals is disclosed, in which a first traffic signal controls traffic travelling in a first direction, and a second traffic signal controls traffic intersecting the traffic travelling in the first direction. The traffic signals each may have a current light phase of either red or green, and possibly also yellow. The disclosed system includes at least one violation prediction image capturing device. The violation prediction image capturing device is employed to provide multiple violation prediction images. The violation prediction images show a number of vehicles, sometimes referred to as the “target” vehicle or vehicles, approaching the first traffic signal. In an illustrative embodiment, the violation prediction images are processed as digitized video frames derived from the output of one or more prediction video cameras employed as image capturing devices.
Information regarding target vehicles shown in the violation prediction images is processed by a violation prediction unit, which is also coupled to a signal reflecting a current light phase of the first traffic signal. The violation prediction unit generates a violation prediction associated with one or more of the vehicles approaching the first traffic signal. The violation prediction indicates a likelihood that a vehicle will violate an upcoming red light phase of the first traffic signal. In an illustrative embodiment, the violation prediction unit is a software thread executing on a processor within a roadside station located proximately to the traffic intersection.
The violation prediction for a given target vehicle may result in a message or signal being sent to a collision avoidance unit or circuit. The collision avoidance unit may, for example, be provided as a software routine executing on a processor within a roadside station. In response to receipt of the violation prediction, the collision avoidance unit may cause at least one violation predicted signal to be asserted. The violation predicted signal is directly or indirectly coupled to the second traffic signal. The second traffic signal may be provided, for example, with a preemption circuit, which may be used to over-ride the transitions of the light cycle for that traffic signal. In response to receipt of the violation predicted signal initiated by the collision avoidance unit, the preemption circuit extends a current red traffic light phase of the second traffic signal for a programmed period of time. The specific time period of the extension may be programmed to be responsive to the current time of day, the current time of year, or the current day of the week, or some other factor or factors. Accordingly, traffic that would have entered the intersection during the red light violation is delayed from entering the intersection, in order to reduce the risk of a collision with the violating vehicle.
Thus there is disclosed an automated traffic light control system which prevents traffic from entering an intersection when a red light violation is occurring or is about to occur. The disclosed system enables vehicle operators to avoid travelling into the intersection by modifying the duration of a red light phase—a mechanism which is conveniently understandable to vehicle operators, and which does not otherwise interfere with traffic flows through the intersection.
REFERENCES:
patent: 3149306 (1964-09-01), Lesher
patent: 3196386 (1965-07-01), Rossi et al.
patent: 3302168 (1967-01-01), Gray et al.
patent: 3613073 (1971-10-01), Clift
patent: 3689878 (1972-09-01), Thieroff
patent: 3693144 (1972-09-01), Friedman
patent: 3731271 (1973-05-01), Muramatu et al.
patent: 3810084 (1974-05-01), Hoyt, Jr.
patent: 3858223 (1974-12-01), Holzapfel
patent: 3866165 (1975-02-01), Maronde et al.
patent: 3885227 (1975-05-01), Moissl
patent: 3886515 (1975-05-01), Cottin et al.
patent: 3920967 (1975-11-01), Martin et al.
patent: 3921127 (1975-11-01), Narbaits-Jaureguy et al.
patent: 4122523 (1978-10-01), Morse et al.
patent: 4200860 (1980-04-01), Fritzinger
patent: 4228419 (1980-10-01), Anderson
patent: 4361202 (1982-11-01), Minovitch
patent: 4371863 (1983-02-01), Fritzinger
patent: 4401969 (1983-08-01), Green et al.
patent: 4884072 (1989-11-01), Horsch
patent: 4887080 (1989-12-01), Gross
patent: 5041828 (1991-08-01), Loeven
patent: 5161107 (1992-11-01), Mayeaux et al.
patent: 5164998 (1992-11-01), Reinsch
patent: 5278554 (1994-01-01), Marton
patent: 5283573 (1994-02-01), Takatou et al.
patent: 5339081 (1994-08-01), Jefferis et al.
patent: 5345232 (1994-09-01), Robertson
patent: 5387908 (1995-02-01), Henry et al.
patent: 5432547 (1995-07-01), Toyama
patent: 5440109 (1995-08-01), Hering et al.
patent: 5444442 (1995-08-01), Sadakata et al.
patent: 5530441 (1996-06-01), Takatou et al.
patent: 5774569 (1998-06-01), Waldenmaier
patent: 5777564 (1998-07-01), Jones
patent: 5801646 (1998-09-01), Pena
patent: 5821878 (1998-10-01), Raswant
patent: 5948038 (1999-09-01), Daly et al.
patent: 5977883 (1999-11-01), Leonard et al.
patent: 6008741 (1999-12-01), Shinagawa et al.
patent: 6100819 (2000-08-01), White
patent: 6111523 (2000-08-01), Mee
Glier Michael T.
Laird Mark D.
Reilly Douglas L.
Small Steven I.
Sybel Randall T.
Nestor, Inc.
Pham Toan
Weingarten, Schurgin Gagnebin & Hayes LLP
Wu Daniel J.
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