WO2001025571A1

WO2001025571A1 - Sequencing control for vehicle access system

Info

Publication number: WO2001025571A1
Application number: PCT/US2000/027099
Authority: WO
Inventors: David T. Proefke; Thomas E. Utter; Robert C. Baillargeon; Thomas W. Pfeffer; Jeffrey R. Coil; Andrew C. Brenz; Kenneth P. Orlando; Tejas B. Desai; Christian O. Johnson; Ronald J. Plichta
Original assignee: HUF NORTH AMERICA; Siemens Automotive Corp; Siemens Automotive LP; General Motors Corp
Current assignee: HUF NORTH AMERICA; Siemens Automotive Corp; Motors Liquidation Co; Siemens Automotive LP
Priority date: 1999-10-04
Filing date: 2000-10-02
Publication date: 2001-04-12
Anticipated expiration: 2002-04-04

Abstract

A vehicle access system includes an electronic key passive signaling device that provides a response signal to a controller after a response time that is based on a sequence identifier within an initiation signal from the controller. In the event that the response signal is not successfully received, because more than one remote signaling device transmits a response signal at the same time, the remote signaling device determines a second response time after which to resent the response signal. The second time preferably is determined based upon an internal piece of data from the remote signaling device, which varies. In the event that the second transmission of the response signal is unsuccessful, a third transmission is completed after a third response time. The third response time preferably is determined based upon a different piece of data from the remote signaling device.

Description

ΓΪ .AT S

1. A method of controlling a vehicle access system having a controller supported on the vehicle and a passive remote signaling device that communicates with the controller, comprising the steps of:

(A) determining that a user desires some action by the system;

(B) generating a signal from the controller that includes a vehicle identifier and a sequence identifier;

(C) receiving the controller signal at the signaling device; (D) determining whether the received vehicle identifier matches a vehicle identifier stored by the signaling device;

(E) determining a response time from the received sequence identifier when the received vehicle identifier matches the stored vehicle identifier; and (F) generating a response signal from the signaling device at the determined response time.

2. The method of claim 1, including re-transmitting the signal of step

(B); receiving the retransmitted signal at the signaling device; determining a second response time based upon a varying piece of data from within the signaling device; and re-transmitting the response signal from the signaling device at the second response time.

3. The method of claim 2, including transmitting the signal of step (B) a third time; receiving the thrice-transmitted signal at the signaling device; determining a third response time based upon another piece of data from within the signaling device; and re-transmitting the response signal from the signaling device at the third response time. 4. The method of claim 1, wherein step (B) includes the substep of including a coded message in the signal and wherein step (F) includes determining a response signal based upon the coded message in the received signal.

5. The method of claim 1, including receiving the signal of step (B) at the signaling device a second time within a period of time from previously receiving the signal of step (B); determining a second response time based upon a varying piece of data from within the signaling device; and re-transmitting the response signal from the signaling device at the second response time.

6. The method of claim 5, including receiving the signal of step (B) a third time at the signaling device within a period of time from receiving the signal of step (B) the second time; determining a third response time based upon another piece of data from within the signaling device; and re-transmitting the response signal from the signaling device at the third response time.

7. The method of claim 6, including receiving the response signal at the controller and causing the system to perform the user desired action.

8. The method of claim 1, including receiving the response signal at the controller and causing the system to perform the user desired action.

9. The method of claim 1, wherein step (E) includes using a sequence location number as at least part of the sequence identifier information. 10. A vehicle access system, comprising: a controller supported on the vehicle that determines when a vehicle user desires an action by the system and generates an initiation signal that includes a vehicle identifier and a sequence identifier; and a remote passive signaling device that receives the signal from the controller, determines whether the vehicle identifier matches a vehicle identifier stored at the signaling device and responsively generates a response signal at a response time based upon the sequence identifier.

11. The system of claim 10, wherein the controller receives the response signal and causes the desired action to be taken.

12. The system of claim 10, wherein the controller determines whether a period of time has elapsed from when the signal was generated and retransmits the initiation signal if no response signal from the signaling device has been received by the controller within the period of time and wherein the signaling device receives the retransmitted signal and responsively generates the response signal at a second response time based upon a piece of data from the signaling device.

13. The system of claim 12, wherein the piece of data from the signaling device comprises a synchronization counter.

14. The system of claim 12, wherein the controller determines whether a period of time has elapsed from when the initiation signal was retransmitted and transmits the initiation signal a third time if no response signal from the signaling device has been received by the controller within the period of time and wherein the signaling device receives the initiation signal transmitted for the third time and responsively generates the response signal at a third response time based upon another piece of data from the signaling device. 15. The system of claim 10, wherein the signaling device receives the initiation signal from the controller a second time within a period of time and wherein the signaling device responsively generates the response signal at a second response time based upon a piece of data from the signaling device.

16. The system of claim 15, wherein the piece of data from the signaling device comprises a synchronization counter.

17. The system of claim 15, wherein the signaling device receives the initiation signal from the controller a third time within a period of time and wherein the signaling device responsively generates the response signal at a third response time based upon another piece of data from the signaling device.

18. A system for controlling access to a vehicle, comprising: a controller supported on the vehicle that generates an initiation signal responsive to determining that a vehicle user desires access to the vehicle; and a remote passive signaling device that generates a response signal at a first response time responsive to the initiation signal and generates the response signal at a second response time if the controller does not successfully receive the first response signal.

19. The system of claim 18, wherein the signaling device generates the response signal at a third response time if the controller does not successfully receive the second response signal.

SEQUENCING CONTROL FOR VEHICLE ACCESS SYSTEM

B ■ AΓKΠRQTIND OF THF TNVFNTTON

This invention generally relates to vehicle access systems. More particularly, this invention relates to a strategy for controlling a vehicle access system having multiple passive remote signal devices.

Keyless vehicle entry systems are well known. Many such systems include a key fob that allows a vehicle owner to remotely unlock the vehicle doors, turn a vehicle ignition on or to activate or deactivate a vehicle alarm system by activating switches on the key fob. Other systems include passive remote signaling devices that provide a signal to a system controller supported on the vehicle without requiring the user to manually activate any switches. Such passive devices, or electronic keys have been proposed as part of a system that allows vehicle ignition control without inserting a key into a mechanical lock. There are various challenges presented in designing effective keyless vehicle control systems. One particular challenge presented by systems including a passive remote signaling device occurs when there are multiple keys for a single vehicle. It is useful, for example, to provide all family members with their own passive device to operate the vehicle as needed. This presents a possible difficulty when more than one passive device is near the vehicle at times where signals are transmitted between the system controller on the vehicle and the passive devices. When more than one passive device is present, it is possible for the response signals to effectively jam the controller, which results in a failure to receive the response signals.

This invention provides a sequencing strategy to control the transmission of signals from passive signaling devices to the system controller to avoid signal jamming at the controller.

SUMMARY OF THF TNVFNTTON

In general terms, this invention is a system for controlling access to a vehicle that includes a sequencing strategy for controlling signal transmission from passive remote signaling devices to ensure proper receipt of such signals at the controller on the vehicle. A system designed according to this invention includes a controller supported on the vehicle that generates an initiation signal responsive to determining that a vehicle user desires access to the vehicle. A remote passive signaling device generates a response signal at a first response time responsive to the initiation signal and generates the response signal at a second response time if the first response signal is not successfully received by the controller. The passive device includes the ability to determine the proper first and second response times. Using different response times before transmitting the response signal is useful to prevent multiple signals jamming the receiver of the controller on a vehicle.

The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows.

P. IFF DESCRIPTION OF THF PR A WINGS Figure 1 diagrammatically illustrates a system designed according to this invention.

Figure 2 is a flow chart diagram illustrating a method of this invention.

DFTATT FT) DESCRIPTION OF THF PRFFFRRFT) EMBODIMENT A vehicle access system 20 includes a remote passive signaling device 22 that communicates with a controller 24 supported on the vehicle. A passive signaling device, as used with this invention, provides signals without requiring any manual activation by the user. Such devices are sometimes referred to as "smart cards" or "electronic keys." In the illustrated example, a second remote passive signaling device 26 also communicates with the controller 24. The illustrated examples of remote signaling devices 22 and 26 show different embodiments of such a component. The signaling device 22 is a card that can be conveniently carried about by an individual. The signaling device 26 is supported on a key body. All communication between the signaling devices 22 and 26 and the controller

24 is wireless. In one example, the controller emits electromagnetic signals that are received by the signaling devices 22 and 26. Signaling devices 22 and 26 provide response signals to the controller 24 that are electromagnetic in one example. Radio frequency signals preferably are used.

The controller 24 preferably controls the operation of various devices on the vehicle. Examples include an ignition kill switch 28, door locks 30 and an engine controller 32. In this example, the controller 24 is responsible for vehicle security features. Additional features can be controlled by the controller 24 and are within the scope of this invention including, for example, a trunk lock.

The controller 24 and the signaling devices 22 and 26 preferably are programmed to accommodate situations where signals from both signaling devices 22 and 26 can possibly interfere with each other and cause signal jamming at the controller 24.

For example, when a user desires access to the vehicle, the controller 24 determines that the user desires the door lock 30 to be opened. The controller 24 then emits an initiation signal. If one or both of the remote signaling devices are within a selected range, the initiation signal from the controller 24 is received at the remote signaling device. The initiation signal preferably includes a vehicle identifier and a sequence identifier.

The remote signaling device preferably is programmed to utilize the vehicle identifier to verify that the signal received at the remote signaling device is from the correct vehicle. If the vehicle identifier matches a vehicle identifier stored in memory on the remote signaling device, the next step is to determine a response time at which to send a response signal to the controller 24.

The remote signaling device preferably is programmed to utilize the sequence identifier information in the initiation signal to determine a response time. The response time provides a slight delay between receiving the initiation signal and transmitting a response signal from the remote signaling device. If a response signal is successfully received by the controller 24, then the appropriate action, such as opening the door locks 30, is completed.

Under some circumstances, both remote signaling devices 22 and 26 will send a response signal at the same time, since they each use the same sequence identifier to determine the appropriate response time. In some such situations, it is not possible for the controller 24 to properly receive the response signal when more than one response signal is present. Whenever the first response signal is not properly received, the controller 24 again transmits an initiation signal. Upon receiving a second initiation signal within a selected time period, the remote signaling device 22 and/or 26 determines a second response time that preferably is based upon a varying piece of data from the remote signaling device. In one example, the synchronization counter within the remote signaling device provides the varying piece of data from which the second response delay time is determined.

Under circumstances where a second transmission of the response signal is not successfully received and the remote signaling device receives the same initiation signal a third time within a short duration, a third response signal is provided. A third time or delay period preferably is used before the response signal is provided a third time. The third response time preferably is determined based some internal piece of data from the remote signaling device. The data used for the third response time may be a constant or a variable. By having the second response time (and, if necessary, the third response time) determined based upon data internal to each remote signaling device, the chances that the response signal will be transmitted synchronously by more than one remote signaling device is minimized. Therefore, this invention provides a sequencing strategy that overcomes difficulties presented by having a controller receive more than one response signal from more than one passive remote signaling device.

In one example, the initiation signal from the controller 24 also contains coded information. The coded information may be used to determined the content of the response signal expected from the remote signaling device. The sequence identifier within the initiation signal provides information preferably based upon its sequence location number indicating when the remote signaling device should respond to the initiation signal. Additional coded information provides an indication to the remote signaling device what content is expected in the response signal.

In one example, the controller 24 continuously emits the initiation signal, which preferably is electromagnetic, until a response signal is received. In another example, the controller 24 generates an initiation signal and then waits a selected period before generating subsequent initiation signals until a successful response is received. Figure 2 includes a flow chart 40 that illustrates the method of this invention. A first sequence occurs at 42 where the controller 24 transmits the initiation signal. The remote signaling device (22 and/or 26) determines the appropriate response time and then transmits the response signal after the appropriate delay. If the response signal is successfully received then the intended function of the system is completed. If the response is not successfully received then a second sequence 44 occurs where the remote signaling device determines a second response time. The response signal is then transmitted after the appropriate delay from the second response time. In the event that the second response signal is not successfully received, a third sequence 46 includes determining a third response time after which to send the response signal for a third time.

In one example, the third response time 46 is repeated until the response signal is successfully received. In another example, the remote signaling devices are programmed to return back to determining the second response time and proceeding as illustrated in Figure 2 until the response signal is successfully received.

Because the second and third response times are based upon data internal to the individual remote signaling device, this invention provides an effective solution to avoid signal interference or jamming at the controller 24.

The preceding description is a exemplary rather than limiting in nature. Variations and modifications to the disclosed embodiments may become apparent to those skilled in the art that do not necessarily depart from the purview and spirit of this invention. The scope of legal protection given to this invention can only be determined by studying the following claims.