Keyless entry multi-channel RKE system

• US 20080197987A1
• Filed: 02/15/2007
• Published: 08/21/2008
• Est. Priority Date: 02/15/2007
• Status: Active Grant

• Current Assignee: Lear Corporation
• Original Assignee: Lear Corporation
• Inventors: Nantz, John S., Ghabra, Riad, King, Ronald O.
• Granted Patent: US 9,085,281 B2
• Time in Patent Office: Days
• US Class Current: 340/426.36
• CPC Class Codes: B60R 25/2072 with means for preventing jamming or interference of a remote switch control signal
• CPC Class Codes: B60R 25/24 using electronic identifiers containing a code not memorised by the user

Abstract

A remote keyless entry system includes a portable communication device for communicating with an electronic control module of a transportation vehicle. The transmitter has at least two selectable communication channels for broadcasting communications signals to the transportation vehicle. A vehicle based electronic control module communicates with the portable communication device. The electronic control module includes a receiver that includes at least two selectable communication channels for receiving RF signals from the portable communication device. A controller selectively energizes the receiver for measuring a RSSI voltage level of each selectable communication channel of the receiver over respective predetermined time periods. The controller determines which of the at least two selectable communication channels includes a lowest noise level based on the measured RSSI voltage level. A channel status update signal is broadcast from the electronic control module to the portable communication device identifying the selected communication channel having the lowest noise level.

Claims

1. A remote keyless entry system for a transportation vehicle comprising:

a portable communication device including a transmitter for broadcasting remote keyless entry commands on any one of a plurality of channels, the portable communication device generating a remote keyless entry command in response to a manual activation identifying a remote keyless entry action, the transmitter broadcasting the remote keyless entry command using a preferred channel in response to the manual activation; and

a vehicle based electronic control module for communicating with the portable communication device and for controlling keyless entry functions within the transportation vehicle, the electronic control module including a receiver for receiving remote keyless entry commands at any one of the plurality of channels, the electronic control module including a RSSI circuit for determining a preferred channel having a lowest noise level, the electronic communication module further including controller for monitoring transmitted remote keyless entry commands from the portable communication device at the preferred channel for a predetermined interval, the controller re-determining the preferred channel after the predetermined interval and repeating the monitoring for a transmitted remote keyless entry command on the re-determined preferred channel, the electronic control module further including a transmitter for transmitting a channel status update signal to the portable communication device identifying the preferred channel during predetermined events;

wherein the portable communication device determines whether the electronic control module acknowledges the transmitted remote keyless entry command, and wherein the portable communication device recursively transmits the remote keyless entry command at each of the plurality of channels until the vehicle controller acknowledges the transmitted remote keyless entry command.

2. A method for selectively activating a two-way communication channel between an electronic control module and a portable communication device in a multi-channel remote keyless (RKE) system, the selected channel having a lowest noise level in the multi-channel remote keyless entry (RKE) system, the method comprising the steps of:

(a) energizing a receiving circuit;

(b) measuring a RSSI voltage level of the first communication channel of a vehicle based electronic control module during a first predetermined period of time;

(c) measuring the RSSI voltage level of a second communication channel of a vehicle based electronic control module during a second predetermined period of time;

(d) comparing the measured RSSI voltage levels of the first communication channel and second communication channel to a predetermined voltage level;

(e) selecting the respective communication channel of the electronic control module having a measured RSSI voltage level closest to the predetermined voltage level;

(f) initiating a counter for a predetermined period of time;

(g) determining if a keyless entry command signal broadcast by the portable communication device is received on the selected communication channel;

(h) de-energizing the receiving circuit for a fourth predetermined period of time;

(i) energizing the receiving circuit;

(j) determining if the third predetermined period of time has elapsed;

(k) repeating steps (a)-(g) if the third predetermined period of time has elapsed, else repeating steps (g)-(j).

3. The method of claim 2 further comprising the steps of:

detecting an occurrence of a predetermined event;

broadcasting from the electronic control module to the portable communication device a channel status update signal that identifies the selected communication channel as determined in step (e).

4. The method of claim 3 further comprising the steps of:

switching the transmitting frequency of the portable communication device to the selected communication channel in response to the portable communication device receiving the channel status update signal;

broadcasting from the portable communication device to the electronic control module a response signal confirming receipt of the channel status update signal.

5. The method of claim 3 further comprising the steps of:

determining if a response signal is received from the portable communication device confirming receipt of the channel status update signal; and

repeatedly broadcasting the channel status update signal to the portable communication device if the response signal is not received by the electronic control module within a respective time period since the occurrence of the predetermined event.

6. The method of claim 2 further comprising the steps of initiating a signal validation program if the keyless entry command signal is present in step (g).

7. The method of claim 6 further comprising the steps of performing a keyless entry function on the vehicle in response to validating the keyless entry command signal.

8. The method of claim 2 comprising the steps of:

broadcasting the keyless entry command signal to the electronic control module;

determining if an acknowledgement signal from the electronic control module is received by the electronic control module in response to the keyless entry command signal;

switching the transmitting frequency of the portable communication device to a next communication channel in response to receiving no acknowledgement signal; and

broadcasting the keyless entry command signal to the electronic control module using the next communication channel.

9. The method of claim 8 further comprising the steps of repeatedly switching the transmitting frequency to a respective next communication channel and broadcasting the keyless entry command signal to the electronic control module on the respective next communication channel until the acknowledgement signal is received.

10. The method of claim 8 further comprising the step of enabling a keyless entry function upon receiving and validating the keyless entry command signal.

11. The method of claim 8 wherein the measured RSSI voltage level is a voltage averaged over time.

12. A remote keyless entry system for a transportation vehicle comprising:

a portable communication device having a transmitter and a receiver for communicating with the transportation vehicle, the transmitter having at least two selectable communication channels for broadcasting communications signals to the transportation vehicle;

a vehicle based electronic control module for communicating with the portable communication device and for controlling keyless entry functions within the transportation vehicle, the electronic control module comprising;

a transmitter for broadcasting communication signals to the portable communication device;

a receiver for receiving RF signals from the portable communication device, the receiver having at least two selectable communication channels for receiving RF signals from the portable communication device; and

a controller selectively energizing the receiver for measuring a RSSI voltage level of each selectable communication channel of the receiver over respective predetermined time periods, the controller determining which of the at least two selectable communication channels includes a lowest noise level based on the measured RSSI voltage level, the controller controlling a broadcast of a channel status update signal to the portable communication device identifying the selected communication channel having the lowest noise level.

13. The remote keyless entry system of claim 12 wherein the transmitter and the receiver are integrated as a transceiver.

14. The remote keyless entry system of claim 12 wherein the communication signal broadcast from the portable communication device includes a keyless entry request command for activating a vehicle entry function.

15. The remote keyless entry system of claim 12 wherein the receiver enables a single respective communication channel during a respective period of time for determining an RSSI voltage level indicator for the respective communication channel.

16. The remote keyless entry system of claim 12 wherein the electronic control module is a keyless entry module.

17. The remote keyless entry system of claim 12 wherein the channel status update signal that includes the channel status update is broadcast in response to a predetermined event occurring.

18. The remote keyless entry system of claim 17 wherein the predetermined event includes opening a door.

19. The remote keyless entry system of claim 17 wherein the predetermined event includes closing a door.

20. The remote keyless entry system of claim 17 wherein the predetermined event includes turning the ignition key to an ignition off position.