Method and system for detecting proximity of an end device to a vehicle based on signal strength information received over a bluetooth low energy (BLE) advertising channel

• US 9,008,917 B2
• Filed: 12/27/2012
• Issued: 04/14/2015
• Est. Priority Date: 12/27/2012
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Gautama, Neeraj R., Kalhous, Amanda J., Hrabak, Robert A., Weigert, Norman J.
• Primary Examiner(s): Nguyen, John Q
• Assistant Examiner(s): ODEH, NADEEM N
• Application Number:
  US13/728,882
• Publication Number:
  US 20140188348A1
• Time in Patent Office: 838 Days
• Field of Search: 701/48, 455/41.2
• US Class Current: 701/48
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
• CPC Class Codes: B60C 23/0416 allocating a corresponding wheel position on vehicle, e.g. front/left or rear/right
• CPC Class Codes: B60C 23/0437 Means for detecting electromagnetic field changes not being part of the signal transmission per se, e.g. strength, direction, propagation or masking
• CPC Class Codes: B60R 25/24 using electronic identifiers containing a code not memorised by the user
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/30 including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
• CPC Class Codes: B60W 2556/00 Input parameters relating to data
• CPC Class Codes: B60W 50/00 Details of control systems for road vehicle drive control not related to the control of a particular sub-unit , e.g. process diagnostic or vehicle driver interfaces
• CPC Class Codes: G07C 2209/63 Comprising locating means for detecting the position of the data carrier, i.e. within the vehicle or within a certain distance from the vehicle
• CPC Class Codes: G07C 2209/64 using a proximity sensor
• CPC Class Codes: G07C 9/00309 operated with bidirectional data transmission between data carrier and locks
• CPC Class Codes: G07C 9/00658 operated by passive electrical keys

Abstract

A passive entry passive start (PEPS) system is provided for performing at least one PEPS function with respect to a vehicle as an end device (e.g., smart phone or key fob, etc.) approaches the vehicle and comes within range for authorization. The vehicle includes a plurality of sensors and a central module. The central module is communicatively coupled to the end device and to the sensors via short-range wireless connections. The central module can determine, based on signal strength information provided from the sensors or the end device, whether the end device is within range for authorization. When the end device is determined to be within range for authorization, the central module can control performance of at least one PEPS function at the vehicle.

Claims

1. A passive entry passive start system, comprising:

an end device; and

a vehicle, comprising;

a plurality of sensors; and

a central module communicatively coupled to the end device and to the sensors via short-range wireless connections, the central module being configured to;

perform a filtered scan for an advertisement message transmitted from the end device over an advertising channel, and, when the end device is detected during scanning, to transmit a discovery message to each of the sensors that indicates that the sensors are to begin scanning for a first advertisement message transmitted from the end device over an advertising channel, wherein the advertising channels are connectionless and do not require a connection to be established for communications to take place over the advertising channels;

wherein each sensor is configured to;

determine signal strength information for the first advertisement message, and to transmit a reporting message to the central module that comprises the signal strength information and a first address for the end device;

wherein the central module is further configured to;

determine, based on signal strength information measured by and provided from the sensors, whether the end device is within range for authorization; and

control performance of at least one passive entry passive start (PEPS) function at the vehicle, when the end device is determined to be within range for authorization.

2. A passive entry passive start system according to claim 1, wherein the central module is further configured to:

determine the distance of the end device from the vehicle based on the signal strength information from reporting messages received from the sensors, and to determine, based on the distance of the end device from the vehicle, whether the end device is within range for authorization.

3. A passive entry passive start system according to claim 2, when the end device is determined to be within range for authorization, wherein the central module is configured to initiate an authorization process with the end device by exchanging messages over a data channel with the end device.

4. A passive entry passive start system according to claim 3,

wherein the data channel is connection-oriented such that a connection must be established before communications take place over the data channel.

5. A passive entry passive start system according to claim 1, wherein the sensors are configured to transmit advertisement messages over an advertising channel, wherein each advertising channel is connectionless and does not require a connection be established for communications to take place over that advertising channel,

wherein the end device is configured to perform a filtered scan for advertisement messages transmitted from the sensors over an advertising channel, to determine the signal strength information from the advertisement messages, and to transmit a reporting message to the central module that comprises the signal strength information corresponding to each sensor;

and

wherein the central module is configured to;

determine, based on signal strength information provided in the reporting message from the end device, the distance of the end device from the vehicle, and to determine, based on the distance of the end device from the vehicle, whether the end device is within range for authorization; and

when the end device is determined to be within range for authorization, wherein the central module is configured to initiate an authorization process with the end device by exchanging messages over a data channel with the end device; and

to control performance of at least one passive entry passive start (PEPS) function at the vehicle when the end device has been authorized.

6. A method, comprising:

establishing, during an initial wireless connection setup phase, wireless connections between a central module disposed within a vehicle and a plurality of sensors disposed within the vehicle;

performing, at the central module, a filtered scan for an advertisement message transmitted from an end device over an advertising channel, wherein the advertisement message comprises a first address for the end device;

transmitting, from the central module to each of the sensors when the central module receives the advertisement message from the end device, a discovery message that indicates that the end device has been detected and that the sensors are to begin scanning for a first advertisement message transmitted from the end device over an advertising channel, wherein each discovery message comprises the first address for the end device that was discovered during the filtered scan, wherein the advertising channel is connectionless and does not require a connection to be established for communications to take place over the advertising channels;

performing, at each of the sensors, a filtered scan for the first advertisement message transmitted from the end device that comprises the first address for the end device, wherein the first advertisement message is communicated over an advertising channel;

at each sensor, upon receiving a first advertisement message from the end device that comprises the first address;

determining, at each sensor, signal strength information for the first advertisement message; and

generating and transmitting, from each sensor, a reporting message to the central module that comprises the signal strength information and the first address for the end device;

performing, at the central module, another filtered scan for reporting messages transmitted from the sensors, wherein each of the reporting messages comprise the first address for the end device;

receiving one or more of the reporting messages at the central module;

determining, at the central module based on signal strength information, whether the end device is within range for authorization; and

when the end device is determined to be within range for authorization, performing at least one passive entry passive start (PEPS) function at the vehicle.

7. A method according to claim 6, wherein the determining step comprises:

determining, at the central module based on signal strength information, a distance of an end device from the vehicle; and

determining, at the central module based on the distance of the end device from the vehicle, whether the end device is within range for authorization.

8. A method according to claim 7, wherein the step of determining, at the central module disposed within the vehicle based on signal strength information, the distance of the end device from the vehicle, comprises:

processing the signal strength information from each of the reporting messages to determine the distance of the end device from the vehicle and a direction that the end device is approaching the vehicle from.

9. A method according to claim 8, when the end device is determined not to be within range for authorization, further comprising:

until the end device is determined to be within range for authorization, repeating the steps of;

performing, at each of the sensors, a filtered scan for the first advertisement message transmitted from the end device that comprises the first address for the end device, wherein the first advertisement message is communicated over an advertising channel;

at each sensor, upon receiving a first advertisement message from the end device that comprises the first address;

determining, at each sensor, signal strength information for the first advertisement message;

generating and transmitting, from each sensor, a reporting message to the central module that comprises the signal strength information and the first address for the end device;

performing, at the central module, another filtered scan for reporting messages transmitted from the sensors, wherein each of the reporting messages comprise the first address for the end device;

receiving one or more of the reporting messages at the central module; and

processing the signal strength information from each of the reporting messages to determine the distance of the end device from the vehicle and a direction that the end device is approaching the vehicle from.

10. A method according to claim 6, when the end device is determined to be within range for authorization, and prior to performing at least one passive entry passive start (PEPS) function at the vehicle, further comprising:

initiating an authorization process with the end device by exchanging Generic Attribute Profile (GATT) messages over a data channel with the end device.

11. A method according to claim 10, wherein the advertising channels are connectionless and do not require a connection be established for communications to take place over the advertising channels, and wherein the data channel is connection-oriented such that a connection must be established before communications take place over the data channel.

12. A method according to claim 10, wherein initiating the authorization process by exchanging GATT messages over a data channel with the end device, comprises the steps of:

transmitting, from the end device to the central module, a GATT request message over a data channel to request a connection with the central module, wherein the GATT request message comprises an address of the end device;

transmitting, from the central module to the end device, a GATT response message over a data channel to confirm that the end device is connected to the central module;

starting a timer at the central module that specifies a timeout period that the central module will wait for a trigger event to occur;

when the trigger event does not occur within the timeout period specified by the timer, cancelling authorization at the central module will cancel the authorization; and

when the trigger event does occur within the timeout period specified by the timer, determining at an electronic control unit (ECU) of the vehicle whether the end device is authorized to access the vehicle, and upon determining that the end device is authorized to access the vehicle, executing processing at the electronic control unit (ECU) to cause the at least one PEPS function to be performed to allow for vehicle access.

13. A method according to claim 10, after the central module determines, based on the distance of the end device from the vehicle, that the end device is within range for authorization, further comprising the steps of:

transmitting, from the central module to each of the sensors, wireless connection request messages; and

upon receiving one of the wireless connection request messages, at each of the sensors, transmitting a wireless connection response message back to the central module to acknowledge that a wireless connection has been established between that particular sensor and the central module; and

transmitting, from the central module to each of the sensors that the central module has established a wireless connection with, a GATT request message over a data channel, wherein each of the GATT request messages comprises a request for the sensor to continue scanning for the end device and acquire signal strength information for the end device.

14. A method according to claim 13, after transmitting, from the central module to each of the sensors that the central module has established a wireless connection with, a GATT request message over a data channel, further comprising the steps of:

transmitting, from the central module to the end device, a connection request message over an advertising channel to request a wireless connection to the vehicle; and

transmitting, from the end device to the central module, a connection response message over an advertising channel to confirm that the end device is connected to the vehicle via the wireless connection.

15. A method according to claim 6, wherein the end device has a peripheral role and the central module has a central role, and wherein prior to the step of performing, at each of the sensors, a filtered scan for a first advertisement message transmitted from the end device, further comprising:

switching, at each of the sensors, from a peripheral role to an observer role; and

prior to the step of generating and transmitting a reporting message that comprises the signal strength information and the first address for the end device, further comprising;

switching, at each of the sensors, from the observer role to the peripheral role.

16. A method according to claim 6, wherein the reporting messages transmitted from the sensors are general advertisement messages transmitted from the sensors over an advertising channel.

17. A method according to claim 6, wherein the reporting messages transmitted from the sensors are GATT messages transmitted from the sensors over a data channel.

18. A method according to claim 6, wherein the step of establishing the wireless connections between the central module and the sensors during the initial wireless connection setup phase, comprises:

performing, at the central module, a filtered scan to detect advertisement messages transmitted by the sensors on advertising channels, wherein each advertising message transmitted by a sensor includes an identifier for the particular sensor;

establishing a wireless connection between the central module and each of the sensors that are detected during the filtered scanning; and

after establishing the wireless connections between the central module and each of the sensors, entering, at each of the sensors, a listening mode until the sensors receive a message from the central module to transition to an active communication mode.

19. A system comprising a vehicle and an end device, the vehicle comprising:

a plurality of tires each having a sensor mounted therein, each of the sensors comprising a chipset and an antenna; and

a central module comprising another chipset and another antenna, the central module being communicatively coupled to the end device and to the sensors via wireless connections, the central module being configured to;

perform a filtered scan for an advertisement message transmitted from the end device over an advertising channel, and, when the end device is detected during scanning, to transmit a discovery message to each of the sensors that indicates that the sensors are to begin scanning for a first advertisement message transmitted from the end device over an advertising channel, wherein the advertising channel is connectionless and does not require a connection to be established for communications to take place over the advertising channel;

wherein each sensor is configured to;

determine signal strength information for the first advertisement message, and to transmit a reporting message to the central module that comprises the signal strength information and a first address for the end device;

wherein the central module is further configured to;

determine, based on signal strength information provided from the sensors, a distance of the end device from the vehicle and whether the end device is within range for authorization based on the distance of the end device from the vehicle; and

control performance of at least one passive entry passive start (PEPS) function at the vehicle when the end device is determined to be within range for authorization.