Automatic determination of traffic signal preemption using GPS, apparatus and method
First Claim
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1. A method for traffic signal preemption for a vehicle traveling on an approach to a signalized intersection having a traffic signal controller, comprising:
- (a) periodically determining the estimated time of arrival of the vehicle at the intersection (VETA);
(b) establishing a selected time period defining a time of arrival (PTA) for the approach;
(c) periodically comparing the VETA to the PTA using a predetermined relationship; and
(d) sending a preemption request to the traffic signal controller requesting preemption when said predetermined relationship is satisfied and any other qualifications for preemption have been satisfied.
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Abstract
For qualification for traffic preemption an area is defined and if the vehicle is in the area it can obtain preemption. The vehicle'"'"'s position is determined, in one embodiment, by use of differential GPS.
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Citations
15 Claims
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1. A method for traffic signal preemption for a vehicle traveling on an approach to a signalized intersection having a traffic signal controller, comprising:
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(a) periodically determining the estimated time of arrival of the vehicle at the intersection (VETA);
(b) establishing a selected time period defining a time of arrival (PTA) for the approach;
(c) periodically comparing the VETA to the PTA using a predetermined relationship; and
(d) sending a preemption request to the traffic signal controller requesting preemption when said predetermined relationship is satisfied and any other qualifications for preemption have been satisfied. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A traffic preemption apparatus for traffic signal preemption for a vehicle approaching a signalized intersection having a traffic signal controller, comprising:
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(a) an intersection subsystem comprising;
(i) a programmed computer having stored in it an approach track for each approach to the intersection for which preemption is desired and having stored in it a selected time period (PTA) for each such approach;
(ii) a receiver to receive signals from a vehicle subsystem;
(iii) a signal circuit to the traffic controller to send requests; and
(b) a vehicle subsystem comprising;
(i) sensors for obtaining data for periodically determining the estimated time of arrival of the vehicle at the intersection (VETA); and
(ii) the vehicle subsystem sending either the data or the periodically determined VETA to the intersection subsystem where the intersection computer either computes the VETA or uses the received VETA and compares the VETA to the PTA and, if a specified predetermined relationship is satisfied, authorizing traffic preemption. - View Dependent Claims (14, 15)
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Specification