US4390951A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for monitoring road traffic to control an associated signaling system
Assignee: Thales SA
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Filing: 1980-09-03
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Granted: 1983-06-28
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Expires: 2000-09-03
Abstract
Abstract An apparatus designed to monitor traffic on a section of road of given length L for modifying the operation of a traffic light at an intersection approached by that road comprises speed-sensing circuits at opposite ends of the surveyed road section, the entrance-side circuit also emitting pulse trains reflecting the lengths Li of passing vehicles. A calculator determines from the measured entrance and exit speeds a mean overall speed VM which is inversely proportional to the mean transit time L/VM and enables the computation of an occupancy density DE(t)=ΣLi/L from which in turn an encumbrance P(t)=DE(t)/VM is derived. The traffic light can be controlled directly by a signal which is proportional to this encumbrance P(t), or which represents a related function F(t). An additional modification of the operating cycle of such traffic light can be brought about by a signal indicating the approach of a vehicle of unusual length on the surveyed road section.
Inventors
- 👤 Raymond Marcy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:46
CPC Classifications
G; G08; G08G; G08G1/00; G08G1/01; G08G1/07; G08G1/08
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
159 words
An apparatus for monitoring traffic on a road section of predetermined length L, comprising: speed-sensing means disposed at said road section; arithmetic means connected to said speed-sensing means for determining a mean overall speed VM of vehicles passing thereover; pulse-generating means disposed at an entrance end of said road section for emitting trains of measuring pulses representing by their number the lengths Li of vehicles found entering said road section; processing means connected to said arithmetic means and to said pulse-generating means for obtaining from said pulse trains and from said mean speed VM a count of said measuring pulses representing the combined length ΣLi of vehicles simultaneously present on said road section and for deriving from said count an occupancy density DE(t)=ΣLi/L; and computer means connected to said processing means and to said arithmetic means for generating an output signal proportional to an encumbrance P(t)=DE(t)/VM indicative of the degree of loading of said road section by vehicular traffic.
Claim 2
Independent Claim
159 words
An apparatus for monitoring traffic on a road section of predetermined length L, comprising: speed-sensing means disposed at said road section; arithmetic means connected to said speed-sensing means for determining a mean overall speed VM of vehicles passing thereover; pulse-generating means disposed at an entrance end of said road section for emitting trains of measuring pulses representing by their number the lengths Li of vehicles found entering said road section; processing means connected to said arithmetic means and to said pulse-generating means for obtaining from said pulse trains and from said mean speed VM a count of said measuring pulses representing the combined length ΣLi of vehicles simultaneously present on said road section and for deriving from said count an occupancy density DE(t)=ΣLi/L; and computer means connected to said processing means and to said arithmetic means for generating an output signal proportional to an encumbrance P(t)=DE(t)/VM indicative of the degree of loading of said road section by vehicular traffic.
Claim 3
Dependent Claim
32 words
An apparatus as defined in claim 1 wherein said speed-sensing means comprises first and second measuring circuits respectively disposed at the entrance end and at an exit end of said road section.
Claim 4
Dependent Claim
45 words
An apparatus as defined in claim 2 wherein said arithmetic means comprises a first and a second averaging circuit, receiving respective speed signals from said first and second measuring circuits, and a third averaging circuit with inputs connected to said first and second averaging circuits.
Claim 5
Dependent Claim
92 words
An apparatus as defined in claim 3 wherein said processing means comprises memory means including a shift register connected to the pulse generating means, said shift register being stepped by clock pulses at a frequency proportional to said mean speed VM, under the control of said third averaging circuit, for arranging said measuring pulses in a pattern reflecting the distribution of vehicles on said road section, said processing means further comprising pulse-counting means connected to said memory means for producing a signal representing said occupancy density DE(t) fed to said computer means.
Claim 6
Dependent Claim
69 words
An apparatus as defined in claim 4 wherein said shift register is part of a middle storage circuit connected in cascade between two other storage circuits with shift registers respectively stepped by clock pulses at frequencies proportional to a mean entrance speed and a mean departure speed under the control of said first and second averaging circuits, said shift registers having outputs connected in parallel to said pulse-counting means.
Claim 7
Dependent Claim
84 words
An apparatus as defined in claim 3 wherein a divider is connected to said third averaging circuit for establishing a transit time T 0 =L/VM, said apparatus further comprising a plurality of adders and switching means for switching inputs of said adders in cyclic succession to said pulse-generating means for summing said measuring pulses during relatively staggered periods corresponding to said transit time T 0 , and multiplexer means sequentially connecting outputs of said adders to a stage determining therefrom said occupancy density DE(t).
Claim 8
Dependent Claim
44 words
An apparatus as defined in claim 1, 2, 3, 4, 5 or 6, further comprising calculating means connected to said computer means for deriving from said output signal a control signal modifying the operation of traffic-regulating means at a location approached by said vehicles.
Claim 9
Dependent Claim
30 words
An apparatus as defined in claim 7 wherein said calculating means comprises a function generator emitting a control signal proportional to a variable F(t) logarithmically related to said encumbrance P(t).
Claim 10
Dependent Claim
28 words
An apparatus as defined in claim 7 wherein said calculating means comprises a function generator emitting a control signal proportional to the square root of said encumbrance P(t).
Claim 11
Dependent Claim
32 words
An apparatus as defined in claim 7 wherein said calculating means comprises a comparator emitting a control signal in response to a deviation of said output signal from a predetermined operating range.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-06-27 | 1986-12-27 | 1987-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-27 | 1990-12-27 | 1991-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-27 | 1994-12-27 | 1995-06-28 | $7700.00 | Window Closed / Lapsed |