MULTIPLE VEHICLE GAP DETECTION AND INTERVAL SENSING SYSTEM
First Claim
Patent Images
1. In a system for detecting and indicating unsafe intervals between successive vehicles traveling in a common traffic lane on a roadway, the improvement comprising:
- a plurality of vehicle detector means including a plurality of radiant energy receivers positioned at transversely spaced locations across said traffic lane to define a fixed detector location along a line normal to the direction of vehicle travel and means for transmitting a beam of radiant energy to each of said receivers to be interrupted by a vehicle present at said fixed detector location, said vehicle detector means being infrared detectors, said transmitting means constituting an infrared source in an elevated position relative to the roadway for directing a beam of radiant energy toward said receivers, and said receivers being embedded in the roadway each including a photosensitive element and means for focusing impinging infrared energy from the source on said element;
a receiver circuit means coupled to each receiver for generating an output signal indicative of vehicle presence whenever said beam is interrupted; and
, a signal buffer circuit coupled to receive the output signal froM each of said receiver circuit means to generate a vehicle presence signal whenever the beam to at least one of said receivers is interrupted.
0 Assignments
0 Petitions
Accused Products
Abstract
Beams of radiant energy, such as from infrared transmitters, are directed in paths downwardly onto a traffic lane to impinge upon associated receiver units that are transversely spaced in the roadway so that vehicles interrupt at least one of the beam paths in passing a fixed detector location. Upon interruption of any of the beam paths, the detector generates an output indicative of the presence of the vehicle. As the vehicle moves out of the beam path, the beam again impinges on the receiver, terminating the vehicle presence output, thus indicating passage of the rear of the vehicle. The vehicle presence outputs from the detectors are applied to a signal buffer arrangement operating as a logical OR circuit to generate a vehicle presence signal whenever the beam path to one or more of the detectors is interrupted and generates a signal when the vehicle leaves the detector. This vehicle presence signal is applied to actuate appropriate timing delay and logic circuitry that defines predetermined gap time intervals between passage of the rear of one vehicle and the front of a following vehicle in order to detect and signal unsafe or illegal '"'"''"'"''"'"''"'"'tailgating'"'"''"'"''"'"''"'"' conditions.
12 Citations
7 Claims
-
1. In a system for detecting and indicating unsafe intervals between successive vehicles traveling in a common traffic lane on a roadway, the improvement comprising:
- a plurality of vehicle detector means including a plurality of radiant energy receivers positioned at transversely spaced locations across said traffic lane to define a fixed detector location along a line normal to the direction of vehicle travel and means for transmitting a beam of radiant energy to each of said receivers to be interrupted by a vehicle present at said fixed detector location, said vehicle detector means being infrared detectors, said transmitting means constituting an infrared source in an elevated position relative to the roadway for directing a beam of radiant energy toward said receivers, and said receivers being embedded in the roadway each including a photosensitive element and means for focusing impinging infrared energy from the source on said element;
a receiver circuit means coupled to each receiver for generating an output signal indicative of vehicle presence whenever said beam is interrupted; and
, a signal buffer circuit coupled to receive the output signal froM each of said receiver circuit means to generate a vehicle presence signal whenever the beam to at least one of said receivers is interrupted.
- a plurality of vehicle detector means including a plurality of radiant energy receivers positioned at transversely spaced locations across said traffic lane to define a fixed detector location along a line normal to the direction of vehicle travel and means for transmitting a beam of radiant energy to each of said receivers to be interrupted by a vehicle present at said fixed detector location, said vehicle detector means being infrared detectors, said transmitting means constituting an infrared source in an elevated position relative to the roadway for directing a beam of radiant energy toward said receivers, and said receivers being embedded in the roadway each including a photosensitive element and means for focusing impinging infrared energy from the source on said element;
-
2. In a system for detecting and indicating unsafe intervals between successive vehicles traveling in a common traffic lane on roadway, the improvement comprising:
- a plurality of vehicle detector means including a plurality of radiant energy receivers positioned at transversely spaced locations across said traffic lane to define a fixed vehicle detector location along a line normal to the direction of vehicle travel and means for transmitting a beam of radiant energy to each of said receivers to be interrupted by a vehicle present at said fixed detector location, said receivers including at least first and second receiver units embedded in said roadway, the first at a position adjacent the center line of said traffic lane spaced therefrom toward said transmitting means and the second at a position on the opposite side of said centerline adjacent the far edge of said traffic lane, and said transmitting means being located in an elevated position alongside said roadway, whereby the beams of radiant energy to said first and second receiver units cross said traffic lane at an acute angle so that one or both are interrupted by any vehicle present at said fixed detector location;
a receiver circuit means coupled to each receiver for generating an output signal indicative of vehicle presence whenever said beam is interrupted; and
, a signal buffer circuit coupled to receive the output signal from each of said receiver circuit means to generate a vehicle presence signal whenever the beam to at least one of said receivers is interrupted.
- a plurality of vehicle detector means including a plurality of radiant energy receivers positioned at transversely spaced locations across said traffic lane to define a fixed vehicle detector location along a line normal to the direction of vehicle travel and means for transmitting a beam of radiant energy to each of said receivers to be interrupted by a vehicle present at said fixed detector location, said receivers including at least first and second receiver units embedded in said roadway, the first at a position adjacent the center line of said traffic lane spaced therefrom toward said transmitting means and the second at a position on the opposite side of said centerline adjacent the far edge of said traffic lane, and said transmitting means being located in an elevated position alongside said roadway, whereby the beams of radiant energy to said first and second receiver units cross said traffic lane at an acute angle so that one or both are interrupted by any vehicle present at said fixed detector location;
-
3. In a system for detecting and indicating unsafe intervals between successive vehicles traveling in a common traffic lane on a roadway, the improvement comprising:
- a plurality of vehicle detector means including a plurality of radiant energy receivers positioned at transversely spaced locations across said traffic lane to define a fixed detector location along a line normal to the direction of vehicle travel and means for transmitting a beam of radiant energy to each of said receivers to be interrupted by a vehicle present at said fixed detector location, said transmitting means being located in an elevated position approximately above the centerline of said traffic lane and said receivers including at least first and second receiver units embedded in said roadway in positions equidistant from and on opposite sides of the centerline of said traffic lane and spaced apart approximately half the width of said traffic lane;
a receiver circuit means coupled to each receiver for generating an output signal indicative of vehicle presence whenever said beam is interrupted; and
, a signal buffer circuit coupled to receive the output signal from each of said receiver circuit means to generate a vehicle presence signal whenever the beam to at least one of said receivers is interrupted.
- a plurality of vehicle detector means including a plurality of radiant energy receivers positioned at transversely spaced locations across said traffic lane to define a fixed detector location along a line normal to the direction of vehicle travel and means for transmitting a beam of radiant energy to each of said receivers to be interrupted by a vehicle present at said fixed detector location, said transmitting means being located in an elevated position approximately above the centerline of said traffic lane and said receivers including at least first and second receiver units embedded in said roadway in positions equidistant from and on opposite sides of the centerline of said traffic lane and spaced apart approximately half the width of said traffic lane;
-
4. In a system for detecting and indicating unsafe intervals between successive vehicles traveling in a common traffic lane on a roadway, the improvement comprising:
- a plurality of vehicle detector means including plurality of radiant energy receivers positioned at transversely spaced locations across said traffic lane to define a fixed detector location along a line normal to the direction of vehicle travel and means for transmitting a beam of radiant energy to each of said receivers to be interrupted by a vehicle present at said fixed detector location, each of said receiving units having a hollow circular housing with its axis aligned perpendicular to the adjacent roadway surface and a sensing assembly adapted to be rotatable within said housing to be aligned in a vertical plane with said transmitting means and including a sensing element and means for selectively focusing radiant energy from said transmitting means upon said sensing element, and having a plate affixed to the bottom of said housing And extending radially outward from the periphery thereof with a plurality of apertures formed therein for permitting the surfacing material of said roadway to flow therethrough upon embedding;
a receiver circuit means coupled to each receiver for generating an output signal indicative of vehicle presence whenever said beam is interrupted; and
, a signal buffer circuit coupled to receive the output signal from each of said receiver circuit means to generate a vehicle presence signal whenever the beam to at least one of said receivers is interrupted.
- a plurality of vehicle detector means including plurality of radiant energy receivers positioned at transversely spaced locations across said traffic lane to define a fixed detector location along a line normal to the direction of vehicle travel and means for transmitting a beam of radiant energy to each of said receivers to be interrupted by a vehicle present at said fixed detector location, each of said receiving units having a hollow circular housing with its axis aligned perpendicular to the adjacent roadway surface and a sensing assembly adapted to be rotatable within said housing to be aligned in a vertical plane with said transmitting means and including a sensing element and means for selectively focusing radiant energy from said transmitting means upon said sensing element, and having a plate affixed to the bottom of said housing And extending radially outward from the periphery thereof with a plurality of apertures formed therein for permitting the surfacing material of said roadway to flow therethrough upon embedding;
-
5. The system improvement of claim 4 wherein:
- said receiver unit further comprises;
a transparent plate sealing the upper end of said housing for admitting said radiant energy to said focusing means; and
wherein said housing has an annular flange extending radially outward at the upper periphery of said housing with a central circular opening for receiving and fixedly supporting said transparent plate to lie in a radial plane circular to the roadway surface, the upper surface of said flange having an outer portion and an inner inwardly beveled portion surrounding said plate with an angle of said approximately 22* relative to the radial plane of said transparent plate, said housing being embedded in said roadway with the upper roadway surface partially covering said inner beveled portion of said flange.
- said receiver unit further comprises;
-
6. In a system for detecting an unsafe headway gap between successive vehicles traveling in a common traffic lane on a roadway, an improved vehicle detector means comprising:
- radiant energy receiver means embedded in a roadway to define a fixed detector location along a line normal to the direction of vehicle travel;
transmitting means for directing radiant energy downwardly across said roadway to impinge on said detector means so that means at said fixed detector location interrupt the path of radiant energy from said transmitting means;
said receiver unit means including hollow cylinder housing means adapted to be embedded in the roadway with its axis aligned perpendicular to the adjacent roadway surface;
a sensing assembly adapted to be rotatably mounted within said housing means in precise alignment with said transmitting means, said assembly including a sensing element and means for selectively focusing upon said sensing element only that radiant energy directed toward said receiver means from a narrow field of view inclusive of said transmitting means; and
, a plate attached to the bottom of said housing and extending radially outward from the periphery thereof with a plurality of apertures formed therein to permit road surfacing materials to flow through during embedding.
- radiant energy receiver means embedded in a roadway to define a fixed detector location along a line normal to the direction of vehicle travel;
-
7. The improved vehicle detector means of claim 6 wherein said receiver unit further comprises:
- transparent plate means sealing the upper end of said housing for admitting said radiant energy from said narrow field of view, including said transmitting means, to said focusing means; and
, an annular flange upon said housing extending radially outward at the upper periphery of said housing and having a sensor circular opening for receiving and fixedly supporting said perpendicular plate, the upper surface of said flange having an outer portion and an inner beveled portion adjacent said plate with an angle of approximately 22* relative to the lateral plane of said transparent plate, whereby said housing is adapted to be embedded in said roadway with the upper roadway surface partially covering said inner beveled portion of said flange.
- transparent plate means sealing the upper end of said housing for admitting said radiant energy from said narrow field of view, including said transmitting means, to said focusing means; and
Specification
-
- Resources
Litigation Campaign Assessment
Thank you for your request. You will receive a custom alert email when the Litigation Campaign Assessment is available.
×
-
Current AssigneeArthur N. Marshall, Charles A. Gregory Jr, James W. Rinehart
-
Original AssigneeArthur N. Marshall, Charles A. Gregory Jr, James W. Rinehart
-
InventorsGregory, Charles A. Jr., Marshall, Arthur N., Rinehart, James W.
-
Primary Examiner(s)Cooper, William C.
-
Application NumberUS05/278,821Time in Patent Office791 DaysField of Search340/31R,38R,38P,38SUS Class Current340/942CPC Class CodesG08G 1/04 using optical or ultrasonic...
