Self-powered vehicle speed sensor

• US 20060033642A1
• Filed: 08/10/2004
• Published: 02/16/2006
• Est. Priority Date: 08/10/2004
• Status: Active Grant

• Current Assignee: Superior Traffic Systems, LLC
• Original Assignee: Speedinfo
• Inventors: Calderone, Theodore, Finlay, Doug
• Granted Patent: US 7,558,695 B2
• Time in Patent Office: Days
• US Class Current: 340/936
• CPC Class Codes: G01S 13/60 wherein the transmitter and receiver are mounted on the moving object, e.g. for determining ground speed, drift angle, ground track G01S13/64 takes precedence
• CPC Class Codes: G01S 7/003 Transmission of data between radar, sonar or lidar systems and remote stations
• CPC Class Codes: G01S 7/4082 using externally generated reference signals, e.g. via remote reflector or transponder

Abstract

A method of sensing vehicle speed is disclosed. The method comprises self-powering a speed sensor and taking a sample of speed sensor data from the speed sensor. The sample of speed sensor data is processed to calculate a calculated speed, and the calculated speed is wirelessly transmitted to a server

Claims

1. A method of sensing vehicle speed comprising:

self-powering a speed sensor,

taking a sample of speed sensor data from the speed sensor,

processing the sample of speed sensor data to calculate speed, and

wirelessly transmitting the calculated speed to a server.

A method of sensing vehicle speed as in claim 1 wherein the speed sensor is a doppler speed sensor that distinguishes direction of vehicles.

2. A method of sensing vehicle speed as in claim 1 that measures the speed of multiple vehicles with one doppler pulse.

3. A method of sensing vehicle speed as in claim 1 wherein the speed sensor turns off power hungry circuitry except when necessary.

4. A method of sensing vehicle speed as in claim 1 wherein the taking a sample of speed sensor data includes turning on a microwave source in the speed sensor.

5. A method of sensing vehicle speed as in claim 1 wherein the taking a sample of speed sensor data includes turning on a preamplifier in the speed sensor.

6. A method of sensing vehicle speed as in claim 1 wherein the taking a sample of speed sensor data includes precharging in-line capacitors in the speed sensor.

7. A method of sensing vehicle speed as in claim 1 wherein the frequency of taking the sample of speed sensor data from the speed sensor depends on the remaining amount of battery power.

8. A method of sensing vehicle speed as in claim 1 wherein the frequency of taking the sample of speed sensor data from the speed sensor depends on the speed of the vehicles.

9. A method of sensing vehicle speed as in claim 1 wherein the processing the sample of speed sensor data to calculate a calculated speed includes calculating an average speed.

10. A method of sensing vehicle speed as in claim 1 wherein the processing the sample of speed sensor data to separate vehicles into cohorts and average the speed of all vehicles found in the sample.

11. A method of sensing vehicle speed as in claim 1 wherein the processing the sample of speed sensor data to calculate a calculated speed includes calculating a high occupancy vehicle speed.

12. A method of sensing vehicle speed as in claim 1 wherein the processing the sample of speed sensor data to calculate a calculated speed includes calculating a non-high occupancy vehicle speed.

13. A method of sensing vehicle speed as in claim 1 wherein the processing the sample of speed sensor data to calculate a calculated speed includes averaging over 4 samples before being transmitted.

14. A method of sensing vehicle speed as in claim 1 wherein the processing the sample of speed sensor data to calculate a calculated speed includes correcting for the angle that the speed sensor is placed at with respect to the road.

15. A method of sensing vehicle speed as in claim 1 wherein transmission of the calculated speed uses a wireless data modem.

16. A device for sensing vehicle speed comprising:

a self-powered speed sensor,

a sampler that takes a sample of speed sensor data from the speed sensor,

a processor that calculates a calculated speed from the sample of speed sensor data, and

a transmitter that wirelessly transmits the calculated speed to a server.