Method and apparatus for self-powered vehicular sensor node using magnetic sensor and radio transceiver

• US 20080246631A1
• Filed: 06/14/2008
• Published: 10/09/2008
• Est. Priority Date: 03/01/2004
• Status: Active Grant

• Current Assignee: Sensys Networks Inc. (Tagmaster AB)
• Original Assignee: Sensys Networks Inc. (Tagmaster AB)
• Inventors: Kavaler, Robert
• Granted Patent: US 8,319,664 B2
• Time in Patent Office: Days
• US Class Current: 340/933
• CPC Class Codes: G08G 1/042 using inductive or magnetic detectors
• CPC Class Codes: G08G 1/14 indicating individual free spaces in parking areas
• CPC Class Codes: G08G 1/141 with means giving the indication of available parking spaces
• CPC Class Codes: G08G 1/145 where the indication depends on the parking areas

Abstract

A vehicular sensor node, circuit apparatus and their operations. Power from power source is controlled for delivery to radio transceiver and magnetic sensor, based upon a task trigger and task identifier. The radio transceiver and the magnetic sensor are operated based upon the task identifier, when the task trigger is active. The power source, radio transceiver, magnetic sensor, and circuit apparatus are enclosed in vehicular sensor node, placed upon pavement and operating for at least five years without replacing the power source components. Magnetic sensor preferably uses the magnetic resistive effect to create magnetic sensor state. Radio transceiver preferably implements version of a wireless communications protocol. The circuit apparatus may further include light emitting structure to visibly communicate during installation and/or testing, and second light emitting structure used to visibly communicate with vehicle operators. Making filled shell and vehicular sensor node from circuit apparatus.

Claims

1. A circuit apparatus for sensing a presence of a vehicle, comprising:

means for maintaining a clock count to create a task trigger and a task identifier;

means for controlling power from a power source delivered to a radio transceiver and a magnetic sensor based upon said task trigger and said task identifier; and

means for operating said radio transceiver and said magnetic sensor based upon said task identifier, when said task trigger is active; and

wherein said power source, said radio transceiver, and said magnetic sensor are enclosed in a vehicular sensor node to operate for at least five years without replacement of said power source.

2. The circuit apparatus of claim 1,

wherein said power source includes one member of a group consisting of at least one battery and at least one photocell;

and

wherein said magnetic sensor has a primary sensing axis for sensing said presence of said vehicle used to create said magnetic sensor state;

wherein the means for controlling said power, further comprises at least one member of the group consisting of;

means for providing a transceiver power delivered to said radio transceiver when said task trigger is active and said task identifier indicates at least one of a sensor report and a clock-alignment; and

means for providing a sensor power delivered to said magnetic sensor when said task trigger is active and said task identifier indicates a sensor reading;

wherein the means for operating comprises;

means for using a magnetic sensor state of said magnetic sensor responding to said presence of said vehicle to create a sensed vehicle state, when said task identifier indicates a sensor reading;

means for sending said vehicle sensed state by said radio transceiver, when said task identifier indicates a sensor report; and

means for receiving a global clock count from said radio transceiver to confirm-update said clock count, when said task identifier indicates a clock-alignment.

3. The circuit apparatus of claim 2, wherein the means for sending, comprises:

said radio transceiver sending said vehicle sensed state to create a received vehicle state at an access point; and

wherein the means for receiving, comprises;

said radio transceiver receiving said global clock count from said access point.

4. The circuit apparatus of claim 1,

wherein the means for controlling said power further comprises:

means for minimizing said power from said power source delivered to said radio transceiver and said magnetic sensor, when said task trigger is inactive; and

means for distributing said power from said power source delivered to said radio transceiver and said magnetic sensor based upon said task identifier, when said task trigger is active;

wherein said magnetic sensor uses a form of the magnetic resistive effect to create said magnetic sensor state; and

wherein said radio transceiver uses at least one channel of a version of at least one wireless communications protocol.

5. The circuit apparatus of claim 4,

wherein said magnetic sensor includes an at least two axis magneto-resistive sensor to create said magnetic sensor state;

and

wherein said wireless communications protocol includes the IEEE 802.15 communications standard.

6. The circuit apparatus of claim 5,

wherein said magnetic sensor includes a two axis magneto-resistive sensor to create said magnetic sensor state;

and

wherein said version of said wireless communications protocol includes the IEEE 802.15.4 communications standard.

7. The circuit apparatus of claim 6,

wherein said magnetic sensor includes a three axis magneto-resistive sensor to create said magnetic sensor state and

wherein said radio transceiver uses a second of said channels of said wireless communications protocol to communicate with a vehicle radio transceiver associated-attached to said vehicle.

8. The circuit apparatus of claim 1,

wherein said means for maintaining, comprises:

a clock timer controllably coupled to a computer to deliver said task trigger and said task identifier, and communicatively coupled with said computer to communicate said clock count;

wherein said means for controlling, comprises;

a power control circuit coupled with said radio transceiver, and coupled with said magnetic sensor to deliver said power;

wherein said means for operating, comprises;

said computer controllably coupled to said power circuit, said radio transceiver, and said magnetic sensor; and

said computer accessibly coupled with a memory containing a program system including at least one member of the group consisting of the program steps of;

operating said radio transceiver and said magnetic sensor based upon said task identifier, when said task trigger is active; and

controlling power from said power source delivered to said radio transceiver and said magnetic sensor based upon said task trigger and said task identifier.

9. The circuit apparatus of claim 8,

wherein the program step controlling power from said power source delivered to said radio transceiver and said magnetic sensor based upon said task trigger and said task identifier, comprising the program steps of:

minimizing said power from said power source delivered to said radio transceiver and said magnetic sensor, when said task trigger is inactive; and

distributing said power from said power source delivered to said radio transceiver and said magnetic sensor based upon said task identifier, when said task trigger is active; and

wherein the program step of operating comprises the program steps of;

using a magnetic sensor state of said magnetic sensor responding to said presence of said vehicle to create a sensed vehicle state, when said task identifier indicates a sensor reading;

sending said vehicle sensed state by said radio transceiver, when said task identifier indicates a sensor report; and

receiving a global clock count from said radio transceiver to confirm-update said clock count, when said task identifier indicates a clock-alignment.

10. The circuit apparatus of claim 1, wherein the means for operating, comprises:

means for using said magnetic sensor state of said magnetic sensor responding to said presence of said vehicle to create said sensed vehicle state, when said task identifier indicates said sensor reading;

means for sending said vehicle sensed state by said radio transceiver, when said task identifier indicates said sensor report; and

means for receiving said global clock count from said radio transceiver to confirm-update said clock count, when said task identifier indicates said clock-alignment.

11. The circuit apparatus of claim 1, wherein at least one of said means for maintaining, said means for controlling, and said means for operating, comprises at least one of a finite state machine, a field programmable logic device, and a computer.

12. The circuit apparatus of claim 1, further comprising at least one member of a group consisting of:

a light emitting structure visibly arranged perpendicular to a primary sensing axis of said magnetic sensor;

a second of said light emitting structures visibly arranged parallel to said primary sensing axis for communicating with a vehicle operator; and

an antenna coupled with said radio transceiver.

13. A vehicular sensor node for sensing a presence of a vehicle, comprising:

a power source;

a radio transceiver;

a magnetic sensor;

means for controlling power from said power source delivered to said radio transceiver and said magnetic sensor based upon a task trigger and a task identifier;

means for maintaining a clock count to create said task trigger and said task identifier;

means for operating said radio transceiver and said magnetic sensor based upon said task trigger and said task identifier; and

wherein said power source, said radio transceiver, and said magnetic sensor operate for at least five years without replacement of said power source.

14. The vehicular sensor node of claim 13, further comprising a plastic shell enclosing said power source, said radio transceiver, said magnetic sensor, said means for controlling, said means for maintaining and said means for operating.

15. The vehicular sensor node of claim 13, further comprising at least one member of a group consisting of:

a light emitting structure visibly arranged perpendicular to a primary sensing axis of said magnetic sensor;

a second of said light emitting structures visibly arranged parallel to said primary sensing axis for communicating with a vehicle operator; and

an antenna coupled with said radio transceiver.

16. The vehicular sensor node of claim 13,

wherein said power source includes one member of a group consisting of at least one battery and at least one photocell;

and

wherein said magnetic sensor has a primary sensing axis for sensing said presence of said vehicle used to create said magnetic sensor state;

wherein the means for controlling said power, further comprises at least one member of the group consisting of;

means for providing a transceiver power delivered to said radio transceiver when said task trigger is active and said task identifier indicates at least one of a sensor report and a clock-alignment; and

means for providing a sensor power delivered to said magnetic sensor when said task trigger is active and said task identifier indicates a sensor reading;

wherein the means for operating comprises;

means for using a magnetic sensor state of said magnetic sensor responding to said presence of said vehicle to create a sensed vehicle state, when said task identifier indicates a sensor reading;

means for sending said vehicle sensed state by said radio transceiver, when said task identifier indicates a sensor report; and

means for receiving a global clock count from said radio transceiver to confirm-update said clock count, when said task identifier indicates a clock-alignment.

17. The vehicular sensor node of claim 16, wherein the means for sending, comprises:

said radio transceiver sending said vehicle sensed state to create a received vehicle state at an access point; and

wherein the means for receiving, comprises;

said radio transceiver receiving said global clock count from said access point.

18. The vehicular sensor node of claim 13,

wherein the means for controlling said power further comprises:

means for minimizing said power from said power source delivered to said radio transceiver and said magnetic sensor, when said task trigger is inactive; and

means for distributing said power from said power source delivered to said radio transceiver and said magnetic sensor based upon said task identifier, when said task trigger is active;

wherein said magnetic sensor uses a form of the magnetic resistive effect to create said magnetic sensor state; and

wherein said radio transceiver uses at least one channel of a version of at least one wireless communications protocol.

19. The vehicular sensor node of claim 18,

wherein said magnetic sensor includes an at least two axis magneto-resistive sensor to create said magnetic sensor state;

and

wherein said wireless communications protocol includes the IEEE 802.15 communications standard.

20. The vehicular sensor node of claim 19,

wherein said magnetic sensor includes a two axis magneto-resistive sensor to create said magnetic sensor state;

and

wherein said version of said wireless communications protocol includes the IEEE 802.15.4 communications standard.

21. The vehicular sensor node of claim 20,

wherein said magnetic sensor includes a three axis magneto-resistive sensor to create said magnetic sensor state and

wherein said radio transceiver uses a second of said channels of said wireless communications protocol to communicate with a vehicle radio transceiver associated-attached to said vehicle.

22. The vehicular sensor node of claim 13,

wherein said means for maintaining, comprises:

a clock timer controllably coupled to a computer to deliver said task trigger and said task identifier, and communicatively coupled with said computer to communicate said clock count;

wherein said means for controlling, comprises;

a power control circuit coupled with said radio transceiver, and coupled with said magnetic sensor to deliver said power;

wherein said means for operating, comprises;

said computer controllably coupled to said power circuit, said radio transceiver, and said magnetic sensor; and

said computer accessibly coupled with a memory containing a program system including at least one member of the group consisting of the program steps of;

operating said radio transceiver and said magnetic sensor based upon said task identifier, when said task trigger is active; and

controlling power from said power source delivered to said radio transceiver and said magnetic sensor based upon said task trigger and said task identifier.

23. The vehicular sensor node of claim 22,

wherein the program step controlling power from said power source delivered to said radio transceiver and said magnetic sensor based upon said task trigger and said task identifier, comprising the program steps of:

minimizing said power from said power source delivered to said radio transceiver and said magnetic sensor, when said task trigger is inactive; and

distributing said power from said power source delivered to said radio transceiver and said magnetic sensor based upon said task identifier, when said task trigger is active; and

wherein the program step of operating comprises the program steps of;

using a magnetic sensor state of said magnetic sensor responding to said presence of said vehicle to create a sensed vehicle state, when said task identifier indicates a sensor reading;

sending said vehicle sensed state by said radio transceiver, when said task identifier indicates a sensor report; and

receiving a global clock count from said radio transceiver to confirm-update said clock count, when said task identifier indicates a clock-alignment.

24. The vehicular sensor node of claim 13, wherein at least one of said means for maintaining, said means for controlling, and said means for operating, comprises at least one of a finite state machine, a field programmable logic device, and a computer.