Wireless induction loop control system

• US 6,265,788 B1
• Filed: 11/05/1999
• Issued: 07/24/2001
• Est. Priority Date: 11/05/1999
• Status: Expired due to Term

• Current Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Valentine, Eric, Davidson, Lee
• Primary Examiner(s): Ballato, Josie
• Assistant Examiner(s): Deberadinis, Robert L.
• Application Number:
  US09/434,778
• Time in Patent Office: 627 Days
• Field of Search: 307/11, 307/10.1, 307/40, 307/10.4, 307/9.1, 455/41, 361/171
• US Class Current: 307/11
• CPC Class Codes: B60R 2021/0104 Communication circuits for data transmission
• CPC Class Codes: B60R 2021/01061 between the airbag system and other vehicle electronic systems
• CPC Class Codes: B60R 2021/01088 wireless
• CPC Class Codes: B60R 21/01 Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents electrical circuits for transmission of signals between steering wheel and the vehicle itself B60R16/027; for electrically actuating belt retractor locking means B60R22/343

Abstract

A wireless control system (30, 70) for distributing electrical control signals to a plurality of controlled devices (36a, 36b, 36c, 74a and 74b), including an electronic control unit (ECU) (32, 72) adapted to communicate with one or more controlled devices (36a, 36b, 36c, 74a and 74b) and an induction loop (34, 73) coupled to the ECU (32, 72) and adapted to provide a magnetic field within the range of the controlled devices (36a, 36b, 36c, 74a, and 74b). Each controlled device (36a, 36b, 36c, 74a and 74b) includes an induction coil (42a, 42b, 42c, 76a and 76b) tuned to couple signals modulated within the magnetic field of the induction loop (34, 74). The controlled devices (74a and 74b) may include a sensor (82a, 82b) and may be adapted to send a status signal (84) to the ECU (72) via the induction loop (73).

Claims

1. A wireless control system for controlling a plurality of devices in an automobile using wireless control signals to said plurality of controlled devices, the system comprising:

an electronic control unit (ECU) having a processor for generating a plurality of control signals communicating with one or more of said controlled devices; and

an induction loop coupled to said ECU and configured to translate control signals generated by the ECU into corresponding electromagnetic fields produced by a current flowing through windings of said induction loop;

wherein said controlled devices are configured to receive said wireless control signals from said ECU via said induction loop, each of said plurality of control devices including an induction coil tuned to a corresponding electromagnetic field generated by said induction loop through said windings.

2. The system according to claim 1 wherein said induction loop is mounted vertically on a firewall of said automobile.

3. The system according to claim 1 wherein said control signals are encoded using frequency division multiplexing (FDM).

4. The system according to claim 1 wherein each of said devices are configured to respond to a unique frequency band.

5. The system according to claim 1 wherein said control signals are digitally encoded prior to transmission with a unique identifier associated with a specific device.

6. The system according to claim 5 wherein said unique identifier comprises an address and an interrupt code.

7. The system according to claim 1 wherein at least one of said devices includes a sensor for detecting the status of said device.

8. The system according to claim 7 wherein said sensor is further adapted to transmit a signal indicting, the status of a device via said induction loop, said sensor adapted to provide bidirectional communications between said ECU and said device.

9. The system according to claim 1 wherein said automobile comprises at least one control mechanism communicably coupled to said ECU and adapted to permit a user to change the state of at least one device.

10. The system according to claim 9 wherein said processor is configured to repeatedly monitor said control mechanism and said devices with sensors in order to detect any requested changes by a user.

11. The system according to claim 1 wherein said ECU further comprises storage for storing control information of said devices and an algorithm for sending said control signal to said devices.

12. The system according to claim 1 wherein said electromagnetic field is adapted to substantially decrease as the distance away from said induction loop increases, to an order of magnitude equal to the inverse cube of the distance.

13. The system according to claim 1 wherein each of said plurality of devices further comprises:

a controller communicably coupled to the induction coil; and

an element;

wherein said controller is coupled to and adapted to operate and control said element.

14. The system according to claim 1 wherein said induction coils are configured such that a time rate of change of magnetic flux through the receiving induction coils generates a voltage in the device controller, indicating to either turn ON or OFF the element as indicated in the wireless control signal.

15. In an automobile equipped with a wireless control system (the “

System”

), a method of communicating electrical control signals to the various electrically controlled devices of the automobile, said System including an electronic control unit (ECU), an induction loop coupled to said ECU and adapted to provide a magnetic field within the range of said controlled devices, each controlled device having an induction coil tuned to couple a range of frequencies modulated within said magnetic field, said method comprising the steps of;

generating a wireless electric control signal; and

transmitting said wireless electric control signal to at least one of said controlled devices.

16. The method according to claim 15 further comprising the step of encoding said wireless electronic control signal with a unique identifier associated with at least one of said controlled devices.

17. The method according to claim 16 wherein the step of encoding is performed using a unique address and interrupt associated with at least one of said controlled devices.

18. The method according to claim 15 wherein said system further comprises at least one control mechanism coupled to said ECU and further comprising the step of examining said control mechanism.

19. The method according to claim 15 wherein at least one said controlled device is adapted to transmit a wireless status signal and further comprising the steps of:

said controlled device sending a wireless status signal; and

said ECU receiving said wireless status signal via said induction loop.

20. The method according to claim 15 wherein said electrical control signals are analog and further comprising the step of encoding said analog control signals prior to transmission.

21. The method according to claim 20 wherein said analog control signals are encoded using frequency division multiplexing (FDM).

22. The method according to claim 21 wherein said electrical control signals are digital and further comprising the step of encoding said digital control signals by modified frequency modulation (MFM).

23. The method according to claim 22 wherein said step encoding by MFM is performed by adding a unique address code and interrupt request sequence associated with a specific controlled device.