SYSTEM AND METHOD TO ENABLE PASSIVE ENTRY

• US 20130214900A1
• Filed: 02/21/2012
• Published: 08/22/2013
• Est. Priority Date: 02/21/2012
• Status: Active Grant

• Current Assignee: FCA US LLC (Stellantis NV)
• Original Assignee: Chrysler Group LLC (Stellantis NV)
• Inventors: Mitchell, Timothy K.
• Granted Patent: US 9,129,455 B2
• Time in Patent Office: Days
• US Class Current: 340/5.61
• CPC Class Codes: G07C 2009/00388 code verification carried out according to the challenge/response method
• CPC Class Codes: G07C 2209/65 using means for sensing the user's hand
• CPC Class Codes: G07C 9/00309 operated with bidirectional data transmission between data carrier and locks

Abstract

A passive entry system is disclosed. The system comprises an unlocking module that performs a key operation in a keyless environment and a plurality of fobs configured to trigger the unlocking module to perform the key operation. each fob has a unique value associated thereto. The unlocking module determines a range of identification values, generates an authentication request packet based on the range, of identification values, and broadcasts the request packet. Each fob receives the request packet; and determines whether the unique identification value of the corresponding fob falls within the range of identification values. The fob also generates a response packet if the unique identification value falls within the range of identification values and transmits the response packet to the unlocking module. The unlocking module receives the response packets from the fobs, and performs the key operation based on one of the received response packets.

Claims

1. A passive entry system comprising:

an unlocking module configured to perform a key operation in a keyless environment, the unlocking module comprising;

a control module that determines a range of identification values, including a start of range value and an end of range value, that generates an authentication request packet based on the range of identification values, and that broadcasts the request packet; and

a plurality of fobs configured to trigger the unlocking module to perform the key operation, each fob having a unique identification value associated thereto, each fob comprising;

a fob transceiver that receives the request packet; and

a response module that determines whether the unique identification value of the corresponding fob falls within the range of identification values and that generates a response packet if the unique identification value falls within the range of identification values, wherein the fob transceiver transmits the response packet to the first transceiver;

wherein the control module is configured to receive response packets from the plurality of fobs, and to perform the key operation based on one of the received response packets.

2. The system of claim 1 wherein the control module performs the key operation when a response packet is received from only one fob.

3. The system of claim 1 wherein when the control module receives the response packets from more than one fob, the control module divides the range of identification values broadcasted in a previous request packet into a first subrange of identification values and a second subrange of identification values and generates a first new request packet based on the first subrange of identification values which is broadcasted by the first transceiver.

4. The system of claim 3 wherein when the control module does not receive a response packet from any fobs after transmitting the first new request packet, the control module generates a second new request packet based on the second subrange of identification values.

5. The system of claim 4 wherein the control module iteratively adjusts the subranges of identification values and generates request packets based on the adjusted subranges until only one fob responds to the request packets.

6. The system of claim 1 wherein the unlocking module is integrated in a vehicle of a plurality of vehicles, wherein the plurality of fobs are in communication with the plurality of vehicles.

7. The system of claim 6 wherein the unlocking module further comprises a proximity sensor that detects a presence of an object in proximity to the vehicle, wherein the first transceiver transmits the request package upon the proximity sensor detecting the presence of the object.

8. The system of claim 7 wherein the request package includes a location identifier indicating a location of the object with respect to the vehicle sensed by the proximity sensor, and the response packet includes a response message that is based on the location identifier.

9. The system of claim 8 wherein the control module wherein the first transceiver is configured to determine a fob location indicating a location of the fob transmitting a response packet, wherein the control module performs the unlocking operation when the fob location matches the location identifier.

10. The system of claim 1 wherein the fob transceiver of a particular fob is configured to transmit the response packet during a particular time slot of a plurality of time slots, wherein the particular time slot that the response packet is transmitted on is based on the value of the unique identification value of the particular fob.

11. A passive entry method comprising:

determining, at an unlocking module, a range of identification values, including a start of range value and an end of range value;

generating, at the unlocking module, an authentication request packet based on the range of identification values;

broadcasting, from the unlocking module, the request packet to a plurality of fobs, each fob having a unique identification value associated thereto;

receiving, at one of the fobs of the plurality of fobs, the request packet;

determining, at the fob, whether the unique identification value of the corresponding fob falls within the range of identification values;

generating, at the fob, a response packet if the unique identification value falls range of identification values;

transmitting, from the fob, the response packet to unlocking module; and

receiving, at the unlocking module, response packets from the plurality of fobs, and to perform a key operation based on one of the received response packets.

12. The method of claim 11 wherein the key operation is performed only when a response packet is received from only one fob.

13. The method of claim 11 further comprising dividing the range of identification values broadcasted in a previous request packet into a first subrange of identification values and a second subrange of identification values and generating a first new request packet based on the first subrange of identification values, wherein the dividing is done when the response packets are received from more than one fob and in response to one request packet.

14. The method of claim 13 further comprising generating a second new request packet based on the second subrange of identification values when a response packet is not received from any of the plurality of the fobs after transmitting the first new request packet.

15. The method of claim 14 further comprising iteratively adjusting the subranges of identification values and generating request packets based on the adjusted subranges until only one fob responds to the request packets.

16. The method of claim 11 wherein the unlocking module is integrated in a vehicle of a plurality of vehicles, and wherein the plurality of fobs are in communication with the plurality of vehicles.

17. The method of claim 16 further comprising detecting a presence of an object in proximity to the vehicle and transmitting the request packet upon detecting the presence of object.

18. The method of claim 17 wherein the request package includes a location identifier indicating a location of the detected object with respect to the vehicle, and the response packet includes a response message that is encoded based on the location identifier.

19. The method of claim 18 further comprising determining a fob location a location of the fob transmitting a response packet, and performing the key operation when the fob location matches the location identifier.

20. The system of claim 11 further comprising transmitting the response packet during a particular time slot of a plurality of time slots, wherein the particular time slot that the response packet is transmitted on is based on the unique identification value of the fob.