WO2005010719A2

WO2005010719A2 - Vehicle access control system with passive user interface

Info

Publication number: WO2005010719A2
Application number: PCT/US2004/023550
Authority: WO
Inventors: Keith Heigl
Original assignee: The Braun Corporaton
Priority date: 2003-07-24
Filing date: 2004-07-21
Publication date: 2005-02-03
Also published as: WO2005010719A3

Abstract

A system for accessing a vehicle establishes a passive user interface proximate the vehicle and allows a physically challenged person or individual with limited dexterity to access the vehicle without active participation. One exemplary embodiment of the access system employs the use of Radio Frequency Identification (RFID) technology for access authorization and includes an RFID subsystem (12) and control module (22) that interfaces with a vehicle's OEM control system. Upon interrogating an RFID transponder (12) programmed with a unique access authorization code, the control module communicates with the OEM control system (22) to coordinate and synchronize operations of unlocking doors, opening sliding doors, and deploying a mobility access device, all without user intervention.

Description

VEHICLE ACCESS CONTROL SYSTEM WITH PASSIVE USER INTERFACE

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/489,858, filed July 24, 2003.

FIELD OF THE INVENTION [0002] The invention relates to access control systems for vehicles. More specifically, the present invention relates to an access control system for vehicles including a mobility access device.

BACKGROUND OF THE INVENTION [0003] Vehicular access control and security systems are well known, and have been used to provide convenience and security to vehicle owners for many years. Numerous vehicle access/security systems for deterring theft, preventing unauthorized access, and obviating vandalism to a vehicle are available from aftermarket providers, or from a vehicle's manufacturer as original (OEM) equipment. Such access and security systems employ various technologies for authenticating or otherwise verifying that an individual is authorized to access the vehicle. Such technologies include radio frequency (RF), optical recognition, voice recognition, and retinal scanning as known in the art. Although the use of the foregoing technologies is adequate for providing vehicular access to the general public, for a vehicle owner who is physically challenged or uses a wheelchair, different obstacles and challenges to vehicular access are present that cannot be overcome by the previously mentioned technologies.

[0004] Traditional vehicular access control systems require that a user actively participate to actuate the system and gain access to the vehicle. Such systems employ an "active" user interface in which a user must manipulate an object such as a key or keyfob, press a button or switch, or otherwise perform a physical activity. Vehicles for the physically challenged often incorporate wheelchair lifts or ramps for facilitating access to the vehicle interior. For personal mobility use, minivans including wheelchair ramps and other modifications have become relatively popular. Such wheelchair ramps can be deployed by using a variety of controls including interior controls, switches incorporated into locks, and remote controls. In order to prevent a person from being crushed or injured during deployment and stowing of the ramp, typical wheelchair ramp control systems require an operator to constantly push the control button during a ramp operation such as unfolding of the ramp from the vehicle. This requirement that the operator actively hold down the control button during ramp operation is somewhat disadvantageous, particularly if the operator is fatigued or has limited hand, arm, or finger dexterity or strength for constantly pressing the control button.

[0005] A common solution to the operator's limited dexterity is to use a "passive" user interface in which a user needs only to be located in proximity to the system to be accessed. One exemplary passive user interface system that is known in the art includes a magnet or a device containing a magnet to activate a hidden magnetically sensitive switch such as a reed switch or the like. The switch activates a control that unlocks the vehicle. A disadvantage to a magnetic actuation system is that any magnet of sufficient strength that comes into proximity of the magnetic switch will activate the control mechanism. Other proximity based sensing systems that require no physical intervention such as voice or optical recognition are more discriminating in providing a method for restricting access to only authorized users, but are expensive and unreliable in certain ambient conditions (e.g., rain, snow, ice, etc.) due to distortion or interference.

[0006] Therefore, in view of the foregoing, there is a need for a low cost proximity- based sensing access system that is secure, robust, and can be integrated into OEM vehicle controls to limit user intervention and automate operation of a wheelchair access system such as a ramp.

SUMMARY OF THE INVENTION [0007] A system is provided for accessing a vehicle via proximity sensing. A passive user interface is established by the system and allows a physically challenged person with limited dexterity to access a vehicle without active participation therewith. One exemplary embodiment of the access system employs the use of radio frequency identification (RFID) technology for access authorization and includes an RFID subsystem comprising a transponder, antenna, and a reader. A control module communicates with the RFID subsystem and the vehicle's OEM control system to coordinate one or more OEM and ramp functions, such as, for example, unlocking doors, opening sliding doors, deploying an access ramp, and kneeling the vehicle, all without user intervention.

BRIEF DESCRIPTION OF THE DRAWINGS [0008] The present invention is described with reference to the accompanying figures, which illustrate embodiments of the present invention. However, it should be noted that the invention as disclosed in the accompanying figures is illustrated by way of example only.

[0009] FIG. 1 is a side view of an exemplary vehicle for use with the subject access control system;

[0010] FIG. 2 is a side view of the vehicle of FIG. 1 illustrated with a ramp in a deployed orientation;

[0011] FIG. 3 is a block diagram of an exemplary vehicle access control system for use with the vehicle of FIG. 1;

[0012] FIG. 4 illustrates an exemplary data structure for an exemplary transponder for use with the system of FIG. 3; and

[0013] FIG. 5 is an exemplary block diagram illustrating the coordinated operation of a vehicle's access system by the system of FIG. 3.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS [0014] Referring now to the figures, a passive access control system 10 including radio frequency identification (hereinafter "RFID") subsystem is described. FIG. 1 illustrates a side view of an exemplary wheelchair-accessible vehicle 100 for use with the passive access control system 10. The vehicle 100 includes at least one vehicle door 102, at least one vehicle lock 104 for locking/unlocking at least one of the vehicle doors 102, and a vehicle body 106. The vehicle door 102 may be any type of sliding or swinging door, as is known in the art, and as shown in FIG. 1, the door 102 is a sliding door, and the vehicle 100 is a minivan. Although the exemplary vehicle 100 is shown in FIG. 1 as a minivan, it should be appreciated that the present system 10 may be used on cars, buses, and other forms of transportation as are generally known. 15] As mentioned above and shown in FIG. 2, the vehicle 100 includes a mobility access device for accessing the vehicle interior. Mobility access devices include ramps, lifting mechanisms, and other devices that assist or otherwise enable a mobility-challenged individual to enter the vehicle with minimal or no physical assistance. The exemplary minivan as illustrated in FIG. 2 includes a ramp 302 that is shown in a fully deployed orientation, however the mobility access device is not limited to a ramp-type structure. The ramp 302 may alternatively be embodied as another mobility access device such as a lift mechanism including a dual parallelogram structure or other lift known in the art, or another mobility access device. Hereinafter, all mobility access devices are collectively referred to as a "ramp" for ease of reference, and the term ramp is not to be held as limiting the system 10 for use with a particular ramp or mobility access device. Vehicle 100 may include an optional kneeling feature, particularly if the vehicle floor has been lowered to accommodate the ramp 302. When the ramp 302 is deployed, the vehicle body 106 is lowered (kneeled) towards the ground from a standing position S (FIG. 1) to a kneeling position with a reduced ground clearance K (FIG. 2). This kneeling function temporarily compresses or modifies the suspension of vehicle 100 to lower vehicle body 106. By lowering body 106 of vehicle 100, the slope of ramp 302 is decreased so as to make entry into vehicle 100 easier, particularly for mobility-challenged individuals using unpowered wheelchairs. Once the passenger is inside the vehicle 100, the ramp 302 can be folded and stowed within the vehicle 100, and the vehicle body 106 can be raised to standing position S.

[0016] As is known, vehicle locks 104 can be actively locked or unlocked by manipulating a key or a keyless entry remote control known as a "keyfob" that is typically supplied by the manufacturer of vehicle 100 or alternatively provided by a third party, such as, for example, the dealer or an aftermarket vehicle alarm system installer. As is known, typical keyfobs communicate with the system 10 to unlock or lock doors, actuate a trunk release, and the like, however a keyfob may be operative to coordinate the various foregoing functions with the deployment of a ramp as disclosed in U.S. Patent Application 10/142,712 assigned to the Assignee herein. Additionally, the system 10 may include an RFID subsystem with at least one RFID transponder 12 (FIG. 3), which is known as a "tag" in the art, that is programmed with an access authorization code. The RFID tag 12 may take on many forms, shapes and sizes, however, several exemplary versions of RFID tags for use with the system 10 are available from Texas Instruments as keyring tags RI-TRP-RFOB-01, RI-TRP-WFOB-01 and the RI-103-112A Tag-it™ miniature transponder inlay. Other tags 12 that are known in the art may be suitably employed with the system 10, so long as the tag 12 is generally maintenance free, requiring no batteries for operation and is operative to retain its programmed data for many years. Additionally, the RFID tag should be counterfeit proof in that its programmed data cannot be modified or deleted. Each of the one or more tags 12 is programmed with data for providing access to a vehicle in which the system 10 is installed. Each tag 12 serves as a key to actuate one or more of the vehicle's functions. For example, instead of using the provided key or keyfob, the locks 104 may be passively locked or unlocked by using one of the tags 12. The foregoing tag functionality is somewhat analogous to the operation of vehicles provided with an owner key and a valet key. The owner key is operative to provide complete access to the vehicle including all doors, the trunk, the glovebox, and the ignition, whereas the valet key is operative to provide limited access to the vehicle, typically to the doors and ignition such that the vehicle owner can safeguard valuables in the trunk or glovebox. Additionally, and as described in further detail below, the foregoing tag 12, or alternatively, a different one of the tags 12 may, in connection with the unlocking of locks 104, also effect the subsequent opening of the door 102 and deploying of a mobility access device such as a lift or ramp, wherein all of the foregoing unlocking, opening, and deploying functions are safely coordinated by the system 10 without operator intervention.

[0017] As shown in FIG. 3, the RFID subsystem of the access control system 10 includes an RFID antenna 14 for providing a passive user interface facilitating communication with the tag 12. The antenna 14 may be an omnidirectional or directional antenna, and the passive user interface generally corresponds with the antenna's broadcast pattern. One exemplary antenna is available from Texas Instruments as a "Series 2000 Stick Antenna" with part number RI-ANT-SOIC. Other antennas 14 that are known in the art may be suitably employed with the system 10, however, as shown in FIG. 2, the antenna should have a relatively compact form to fit inconspicuously within the vehicle, such as in a vehicle taillight or behind a vehicle body panel. Additionally, the antenna 14 should provide the ability to read and distinguish multiple tags 12 in close proximity, and cooperate with an RFID reader for tag read time on the order of 100 ms. [0018] As shown in FIG. 3 and as known in the RFID art, the RFID subsystem includes an RFID reader 20. The antenna 14 is connected to the reader 20 via a cable 18 such that the reader 20 may communicate with the one or more tags 12. As shown in FIG. 3, the reader 20 reads or "interrogates" tags 12 through antenna 14 that emits an excitation field comprising the passive user interface 16. The passive user interface 16 provides for proximity coupling between the tag 12 and antenna 14 that energizes the tag 12 for transmission of the tag's programmed data. The tag's transmitted data is received by the antenna 14 and communicated to the reader 20, which processes and interprets the data. One exemplary reader 20 is available from Texas Instruments as a "Series 2000 Micro Reader" with part number RI-STU-MRD1, however other suitable readers may be used as well. To access the vehicle 100, a user would only have to pass the RFID tag 12 within 4 to 6 inches of the RFID antenna 14 for interrogation by the reader 20. To this end, the tag 12 may communicate with the system 10 even when left in a user's purse or pocket. Advantageously, a tag 12 may be integral with or otherwise affixed to a mobility aid device such as a wheelchair, walker, scooter, or the like. Such an arrangement would obviate the need for an individual to manipulate the tag 12, and would also prevent theft or accidental loss of the tag 12.

[0019] When an RFID tag 12 is brought in proximity to the passive user interface 16, the tag 12 is interrogated for authentication by the RFID reader 20 and control module 22. The reader 20 or control module 22 may include a memory comprising one or more codes relative to the programmed data of the one or more tags 12. As is known in the art, the exemplary tags mentioned above may be programmed with up to two thousand forty-eight bits of data organized in up to sixty-four blocks of thirty-two bits each. One exemplary data structure for a tag 12 is illustrated in FIG. 4. The control module 20 having receiving the programmed data of the RFID tag 12 comprising an access code, attempts to authenticate the code by cross-referencing the received code with the stored codes. If the received code is found to be present and valid in the memory, the control module 22 proceeds to communicate with the OEM systems, particularly the body control module (BCM) 24 via the OEM vehicular communications bus 26 for unlocking and opening doors, and directly with the mobility access system components (e.g., ramp and kneel controls 30, 32). Further, in view of the exemplary illustrated data structure of FIG. 4, the tag 12 may (in addition to a unique identification code) transmit programmed information including a signal for execution by the control module 22 and/or the OEM control module 24. To this end, the tag 12 may passively and directly effect state changes in the vehicle 100 and its various OEM and aftermarket subsystems. For example, one tag's data may include a control signal that can be acted on directly by the control module 22 for only unlocking the vehicle doors, which is somewhat analogous to a "valet" key. Another tag's data may include a control signal that can be acted on directly by the control module 22 for unlocking and opening a sliding door and deploying a ramp, which is somewhat analogous to a "master" key. Such control signals may be relayed by the reader 20 to the control module 22 and authenticated and processed for action thereon.

[0021] As shown in FIG. 3, the control module 22 may be an aftermarket system that seamlessly integrates with the OEM control module 24 so the control module 22 can monitor signals sent to vehicle systems such as the power sliding door module (PSDM) 28, ramp control 30, and kneel control 32 as well as other vehicular systems 34. As the ramp and kneel control systems 30, 32 are typically systems that are provided with and under direct control of the control module 22, they are directly linked with the control module 22 since they are generally unable to communicate directly with the OEM systems 24, 28, 34 over the bus 26. The control module 22 may include a programmable logic control system (PLC), a microprocessor, microcontroller or other type of electronic controller as known in the art. In one example, the OEM control module may be operative to control a door motor such as an AC or DC motor for moving a power sliding door, and one or more solenoids for locking and unlocking one or more power locks, among other thing. The control module may be operative to control a ramp motor, pump, or actuator for deploying and stowing a ramp, and a kneeling motor or actuator for compressing or lowering the vehicle's suspension. The control module and OEM control module may be operatively coupled together via a bus such as an SAE Jl 850 bus or other means such as optical fiber, wireless communications and the like so that the control module may detect, intercept, delay, and re- send signals sent to the OEM control module for the purpose of synchronizing the door, ramp and kneeling motors to obviate user intervention. Further, the control module and the OEM control module may be linked to a plurality of sensors for detecting the status or state of the components of the system 10 such as the door position, ramp position, kneeling position, among other things such that unsafe operating conditions and operator errors are obviated, for example, the system 10 may not permit deployment of the ramp when the door is closed, or the vehicle may not be shifted out of park when the ramp is deployed.

[0022] As shown, control module 22 is operatively coupled to communication pathway 26 in order to control and synchronize the operation of the PSDM 28, ramp control 30, and kneel control 32 relative to an access code received through the passive user interface 16. Further, the BCM 24 and PSDM 28 may have an inactive, idle, or sleep state for conserving vehicle power when the vehicle 100 is not active (e.g., parked). Therefore, as shown in FIG. 3, the control module 22 may send "wake-up" signals to the BCM 24 and PSDM 28 as needed over the OEM bus 27, or alternatively over dedicated wake-up communication links such as, for example, when an access code is received through the passive user interface 16. For example as previously mentioned, one tag 12 may be programmed with a code that is operatively associated with command signals in the control module 22 to only unlock the vehicle doors. Another tag 12 may be programmed with a code that is operatively associated with command signals in the control module 22 to unlock and open a sliding door and deploy a ramp. FIG. 5 shows a flow diagram 400 illustrating a process for deploying ramp 302 according to one exemplary embodiment. As mentioned above, PSDM 28 may be normally asleep. When control module 22 authenticates a tag 12, the control module 22 may awaken and communicate with BCM 24 such that BCM 24 communicates with the PSDM 28 and sends an "open door" signal thereto on the OEM bus 26. By monitoring the bus 26, control module 22 detects and intercepts this "open door" command signal in block 402 and thereafter sends a wake-up signal to PSDM 28 in block 404. Control module 22 then relays the intercepted "open door" command signal via bus 26 to the PSDM 28 in block 406 so that the door begins to open. In block 408, control module 22 monitors the bus 26 for a signal from PSDM 28 indicating that door 102 is open and continues to monitor the bus 26 until the signal is received. Once door 102 is open, the PSDM 28 sends this "opened" signal over bus 26 in order to notify BCM 22 that the door 102 is open. When the control module 22 detects this "opened" signal, control module 22 puts PSDM 28 back to sleep in block 410 by sending a sleep signal on the bus 26. Knowing door 102 is open, control module 22 in block 412 kneels the vehicle and in block 414 deploys the ramp 302 while at the same time monitoring for ramp and vehicle obstructions. The foregoing-described blocks and steps may occur in other sequences, for example, the ramp may be deployed before the vehicle is kneeled. Thus, as described an illustrated in FIG. 5, by intercepting OEM vehicular communications, including wake-up signals, the control module 22 can coordinate and synchronize the operations of the kneel control 32, ramp control 30, and door control 28 without user intervention upon interrogating and authenticating a tag 12.

[0023] As mentioned above and shown in FIG. 2, the RFID antenna 14 may be hidden behind a fiberglass vehicle panel or in a taillight. It is important to locate the RFID antenna 14 such that the passive user interface 16 is established away from the sliding door 102 and deploying ramp 302 to ensure the safety of the tag-holder. Thus, by approaching the vehicle taillight the individual wishing to access the vehicle 100 can activate the system 10 using an RFID tag 12 integrated into a wheelchair and can remain at a safe distance from a deploying ramp 302 to prevent accidental injury. Further, the system 10 may require that the tag 12 remain in proximity and communication with the passive user interface 16 until the ramp 302 is completely deployed. As such, if the user were to move out of the passive user interface 16, the system 10 may halt further deployment of the ramp until the tag 12 is once again readable by the antenna 14. Once the ramp 302 is deployed and the vehicle 100 has kneeled to a reduced vehicle ground clearance shown as "K" in FIG. 2, the user may enter the vehicle 100 and operate the access system 10 by an internal switch 304 to coordinate standing the vehicle 100 to its standard ground clearance shown as "S" in FIG. 1, storage of the ramp 302, and door closure. Still further, the tag 12 may authenticate the user for starting the ignition of the vehicle to prevent vehicle theft.

[0024] While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that various exemplary embodiments have been shown and described and that all changes and modifications thereto that come within the spirit of the invention are desired to be protected. To this end, other interconnection arrangements of the control module 22, BCM 24, and PSDM 28 are possible to reduce handshaking between the modules . For example, control module 22 may in some instances be operative to replace the BCM in its entirety such that the control module 22 may communicate directly with the PSDM and mobility access device. [0025] While the present invention has been illustrated by a description of various embodiments and while these embodiments have been set forth in considerable detail, it is intended that the scope of the invention be defined by the appended claims. It will be appreciated by those skilled in the art that modifications to the foregoing preferred embodiments may be made in various aspects. It is deemed that the spirit and scope of the invention encompass such variations to be preferred embodiments as would be apparent to one of ordinary skill in the art and familiar with the teachings of the present application.

Claims

WHAT IS CLAIMED IS:

1. A vehicle access control system comprising: a control module linked to communicate with a vehicle's OEM control system, the control module operative to intercept control signals from the OEM control system and relay said signals to OEM systems, the control module further comprising a memory for storing an access authorization code; a radio frequency identification reader linked to communicate with the control module, the reader providing radio frequency and control functions to establish a passive user interface area proximate to at least a portion of the vehicle; a radio frequency identification antenna linked to communicate with the reader, the antenna transmitting an excitation field and receiving data in response to the field; and a radio frequency identification transponder programmed with the access authorization code, the transponder transmitting its code for accessing the vehicle when located proximate to the passive user interface area.

2. The vehicle access control system of claim 1 wherein the control module associates one or more OEM commands with the access authorization code for controlling the OEM systems relative to the transponder.

3. The vehicle access control system of claim 1 wherein the antenna is disposed within a portion of the vehicle.

4. The vehicle access control system of claim 3 wherein the antenna is disposed within a vehicle taillight.

5. The vehicle access control system of claim 3 wherein the antenna is disposed behind a vehicle body panel.

6. The vehicle access control system of claim 1 wherein the control module is further linked to communicate with a mobility access device for operation thereof.

7. The vehicle access control system of claim 6 wherein the control module is operative to control the mobility access device and OEM systems in a coordinated manner.

8. The vehicle access control system of claim 7 wherein the mobility access device comprises a wheelchair ramp.

9. The vehicle access control system of claim 7 wherein the antenna is located such that the passive user interface area is established distal from the wheelchair ramp.

10. The vehicle access control system of claim 7 wherein the mobility access device comprises a wheelchair lift.

11. The vehicle access control system of claim 1 wherein the transponder is affixed to a mobility aid device

12. The vehicle access control system of claim 11 wherein the mobility aid device is a wheelchair.

13. A vehicle having a door and a ramp that provides wheelchair access to the vehicle, the door and ramp in communication with a mobility access system comprising: one or more transponders, each transponder including a unique authorization code; a control module operative to control the door and ramp, the module comprising: a transponder reader for interrogating the transponders, and a memory including one or more stored authorization codes, each of the stored authorization codes associated with one or more command signals operative to control the door and ramp; and a passive user interface area proximate to the vehicle, the interface operative to relay an authorization code from a transponder to the control module for controlling the door or ramp.

14. The vehicle of claim 13 further comprising an omnidirectional antenna linked with the reader for facilitating the interrogation of a plurality of transponders.

15. The vehicle of claim 14 wherein the antenna is located distal from the ramp.

16. The vehicle of claim 15 wherein the antenna is located at the rear of the vehicle.

17. The vehicle of claim 16 wherein the antenna is located within a vehicle taillight.

18. The vehicle of claim 16 wherein the antenna is located behind a vehicle body panel proximate the rear of the vehicle.

19. The vehicle of claim 13 wherein at least one of the transponders is integral with a mobility aid device.

20. The vehicle of claim 19 wherein the mobility aid device is a wheelchair.

21. A vehicle access control system for controlling a mobility access device, the system comprising: a transponder including a unique authorization code, the transponder operative to transmit said unique authorization code when positioned proximate a passive user interface area; and a control module including a transponder reader for receiving the transmitted unique authorization code, the control module authenticating the code and controlling the mobility access device in response to said authenticated code.

22. The vehicle access control system as recited in claim 21 further comprising an antenna linked to the control module for establishing the passive user interface area.

23. The vehicle access control system as recited in claim 22 wherein the passive user interface area is coupled to at least a portion of the vehicle.

24. The vehicle access control system as recited in claim 23 wherein the passive user interface area is coupled to the vehicle distal from the mobility access device.

25. The vehicle access control system as recited in claim 24 wherein the mobility access device is located at a side door of the vehicle and the passive user interface is located proximate the rear of the vehicle.

26. The vehicle access control system as recited in claim 25 wherein the antenna is disposed within a vehicle taillight.

27. The vehicle access control system as recited in claim 25 wherein the antenna is disposed behind a vehicle body panel, which is formed of a electromagnetically transmissive material.

28. The vehicle access control system as recited in claim 21 wherein the transponder is integral with a mobility aid device.

29. The mobility access system of claim 28 wherein the mobility aid device is a wheelchair.