Wireless self-powered sensor

• US 7,710,288 B2
• Filed: 11/16/2007
• Issued: 05/04/2010
• Est. Priority Date: 02/09/2006
• Status: Expired due to Fees

• Current Assignee: Alps Automative, Inc. (Alps Alpine Co., Ltd.)
• Original Assignee: Alps Automative, Inc. (Alps Alpine Co., Ltd.)
• Inventors: Seguchi, Koji, Dulgerian, James
• Primary Examiner(s): Wu; Daniel
• Assistant Examiner(s): Sherwin; Ryan W
• Application Number:
  US11/941,708
• Publication Number:
  US 20080129482A1
• Time in Patent Office: 900 Days
• Field of Search: 340/457.1, 340/686.1, 340/686.4, 340/686.5, 340/687, 340/542, 307112-144, 310/10, 310/12, 335/177, 335/179, 335/180, 335270-292, 324/207.26
• US Class Current: 340/686.4
• CPC Class Codes: B60R 2021/01088 wireless
• CPC Class Codes: B60R 2022/4816 for sensing locking of buckle
• CPC Class Codes: B60R 22/48 Control systems, alarms, or interlock systems, for the correct application of the belt or harness

Abstract

A self-powered sensor detects or measures an event by converting one form of energy into another form. The converted energy may be conditioned and regulated to drive a wireless transmitter and encoder. A receiver may detect and validate a received message. If validated, the message may be processed or decrypted and processed to determine what has been identified or requested.

Claims

1. A wireless self-powered sensor, comprising:

an electrodynamic generator adapted to induce a first electrical signal in response to a substantially planar movement of a carrier, a first magnet, or a second magnet between a first position and a second position that causes a change in a magnetic field direction in the carrier, the substantially planar movement caused by an event in a vehicle;

where the carrier comprises a metal core and a wire loop wrapped around the metal core, the first magnet has a first magnetic polarity, and the second magnet has a second magnetic polarity, the second magnet positioned such that the second magnetic polarity is substantially opposite of the first magnetic polarity;

a power conditioning circuit electrically coupled to the electrodynamic generator, the power conditioning circuit adapted to rectify and regulate the first electrical signal into a second electrical signal, the second electrical signal comprising a substantially constant voltage;

an encryption circuit electrically coupled to the electrodynamic generator and the power conditioning circuit, the encryption circuit sourced by the second electrical signal and adapted to encode a unique message in a data packet; and

a radio frequency transmitter electrically coupled to the encryption circuit, the radio frequency transmiffer sourced by the second electrical signal and adapted to transmit the data packet,

wherein the substantially planar movement causes a break in contact between the carrier and one of the first magnet or the second magnet.

2. The sensor of claim 1, where the event comprises an engagement or a release of a belt buckle, an opening or a closing of a door, or an engagement of a switch controlling a movement of a power window.

3. The sensor of claim 1, where the electrodynamic generator further comprises an actuator that causes the substantially planar movement of the carrier, the first magnet, or the second magnet between the first position and the second position.

4. The sensor of claim 1, where the carrier is adapted to carry a magnetic flux and the inducement of the first electrical signal is caused by a change in the magnetic flux direction as a result of the change in the magnetic field direction.

5. The sensor of claim 1, where the carrier further comprises a flux bar coupled to the core, where the flux bar is adapted to carry a magnetic flux, is in contact with the first magnet when in the first position, and is in contact with the second magnet when in the second position, and the inducement of the first electrical signal is caused by a change in the magnetic flux direction as a result of the change in the magnetic field direction.

6. The sensor of claim 1, where the carrier is in contact with the first magnet when in the first position and is in contact with second magnet when in the second position, and the substantially planar movement causes the carrier to break contact with one of the first and second magnets and allow attraction to the other of the first and second magnets.

7. The sensor of claim 1, where the substantially planar movement of the carrier comprises moving the carrier with respect to the first and second magnets, the first and second magnets being fixed.

8. The sensor of claim 1, where the substantially planar movement of the first and second magnets comprises moving the first and second magnets with respect to the carrier, the carrier being fixed.

9. The sensor of claim 1, further comprising return springs adapted to bias the carrier, the first magnet, or the second magnet from the second position to the first position.

10. A method, comprising:

inducing a first electrical signal in response to a substantially planar movement between a first position and a second position of a carrier among a first magnet and a second magnet that causes a change in a magnetic field direction, the substantially planar movement caused by an event in a vehicle;

conditioning the first electrical signal to a second electrical signal, the second electrical signal comprising a substantially constant voltage;

sourcing an encryption and a transmission process with the second electrical signal;

encoding a unique message in a data packet; and

transmitting the data packet,

wherein the substantially planar movement causes a break in contact between the carrier and one of the first magnet or the second magnet.

11. The method of claim 10, where the event comprises an engagement or a release of a belt buckle, an opening or a closing of a door, or an engagement of a switch controlling a movement of a power window.

12. The method of claim 10, where transmitting the data packet comprises transmitting a radio frequency signal.

13. The method of claim 10, further comprising sensing the event and generating a signal indicating the event.

14. The method of claim 10, further comprising sourcing a sensing process with the second electrical signal.

15. The method of claim 10, where conditioning the first electrical signal to a second electrical signal comprises rectifying the first electrical signal and regulating the first electrical signal to the second electrical signal.

16. The method of claim 10, further comprising receiving the data packet, and decrypting the data packet to the unique message.

17. A wireless self-powered sensor, comprising:

an electrodynamic generator adapted to induce a first electrical signal in response to a substantially planar movement of a magnet carrier between a first position and a second position that causes a change in a magnetic field direction in an assembly, the assembly comprising a bobbin and a wire coil wrapped around the bobbin, and the planar movement caused by an engagement or a release of a belt buckle;

where the magnet carrier comprises a first magnet with a first magnetic polarity and a second magnet with a second magnetic polarity, the second magnet positioned such that the second magnetic polarity is substantially opposite of the first magnetic polarity;

a power conditioning circuit electrically coupled to the electrodynamic generator, the power conditioning circuit adapted to rectify and regulate the first electrical signal into a second electrical signal, the second electrical signal comprising a substantially constant voltage;

an encryption circuit electrically coupled to the electrodynamic generator and the power conditioning circuit, the encryption circuit sourced by the second electrical signal and adapted to encode a unique message in a data packet; and

a radio frequency transmitter electrically coupled to the encryption circuit, the radio frequency transmitter sourced by the second electrical signal and adapted to transmit the data packet,

where the substantially planar movement of the magnet carrier comprises moving the magnet carrier with respect to the assembly, the assembly being fixed.

18. The sensor of claim 17, where the electrodynamic generator further comprises an actuator that causes the substantially planar movement of the magnet carrier between the first position and the second position.

19. The sensor of claim 17, where the inducement of the first electrical signal is caused by a change in the magnetic flux direction as a result of the change in the magnetic field direction.

20. The sensor of claim 17, where the assembly further comprises a flux bar coupled to the wire coil, and where the flux bar is adapted to carry a magnetic flux, is in contact with the first magnet when in the first position, and is in contact with the second magnet when in the second position, and the inducement of the first electrical signal is caused by a change in the magnetic flux direction as a result of the change in the magnetic field direction.

21. The sensor of claim 20, where the substantially planar movement of the magnet carrier comprises moving the magnet carrier with respect to the flux bar, the flux bar being fixed.

22. The sensor of claim 17, further comprising return springs adapted to bias the magnet carrier from the second position to the first position.

23. The sensor of claim 17, where the electrodynamic generator is coupled to a buckle receptacle.

24. The sensor of claim 17, further comprising an energy storage device adapted to store the second electrical signal;

and where the unique message comprises a status of the belt buckle, and the radio frequency transmitter is sourced by the energy storage device and is further adapted to continuously transmit the data packet.