Abstract:
Medium-range and global network information and control for a vehicle is achieved with a portable wireless key fob, a user-provided nomadic device, and a vehicle-installed telematics unit including a medium-range RF transceiver and a wireless network transceiver. The fob includes a medium-range RF transceiver for bi-directional communication with the telematics unit, and a short-range wireless transceiver for bi-directional communication with the nomadic device. The fob communicates with the telematics unit in a conventional manner, and also relays information between the telematics unit and the nomadic device. If a communication initiated via the fob cannot be completed because the fob is out of range, the communication is sent to the nomadic device for network transmission to the telematics unit. If a communication initiated via the nomadic device cannot be completed due to inadequate signal reception, the communication is sent to the fob for RF transmission to the telematics unit.

Description:
RELATED APPLICATIONS 
       [0001]    This is a continuation-in-part of co-pending U.S. patent application Ser. No. 11/973,716 (Attorney Docket No. DP-316326), filed Oct. 10, 2007, and Ser. No. 12/150,872 (Attorney Docket No. DP-316582), filed May 1, 2008, which applications are assigned to the assignee of the present invention. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to remote communication and control for a vehicle, and more particularly to a fault tolerant apparatus utilizing a wireless key fob, a user-carried wireless nomadic device, and a vehicle-installed telematics unit. 
       BACKGROUND OF THE INVENTION 
       [0003]    Various communication devices have been used to enable remote access and control of a motor vehicle. For example, short-range and medium-range wireless RF communication devices have been used to activate door locks, to start the engine, to access vehicle status information, and so forth. The communication device can be in the form of a so-called “smart key fob” or a nomadic device (such as a cell phone or PDA) equipped with an RF transceiver in the form of a SDIO card for example, as described in the U.S. Pat. No. 7,224,262 to Simon et al. Another approach, described for example in the U.S. Pat. No. 6,970,703 to Fuchs et al., is to configure both the vehicle and the user-borne nomadic device for both short-range RF communication and global network communication. In that case, the short-range RF communication link is used for remote access and control if the nomadic device is within a prescribed range of the vehicle; and otherwise, the global network communication link is used. 
         [0004]    The above-described approaches all have significant drawbacks. For example, smart key fobs tend to be both too large and too expensive when human-machine interface (HMI) devices such as keypads and displays are integrated into the fob. And localizing all of the vehicle information and control functionality into a single special-purpose nomadic device is also undesirable because many users frequently change nomadic devices as new styles, features and functions become available, and because all functionality is lost if the nomadic device is lost or fails, or has a discharged battery. Accordingly, what is needed is an improved and lower-cost way of achieving both medium-range and long-range communication and control for a vehicle. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention is directed to an improved wireless communication system that provides both medium-range and long-range communication and control for a vehicle with a portable wireless key fob, an user-provided wireless nomadic device, and a vehicle-installed telematics unit that includes both a medium-range wireless RF transceiver and a global wireless network transceiver. The portable fob includes a medium-range wireless RF transceiver for bi-directional communication with the telematics unit, and a short-range wireless transceiver for bi-directional communication with the user&#39;s nomadic device. The fob communicates with the telematics unit in a conventional manner, and also relays information between the telematics unit and the user&#39;s nomadic device. 
         [0006]    Communications can be initiated by the telematics unit or by the user via the fob or nomadic device. If a command or data request communication initiated via the fob cannot be completed because the fob is not within RF range of the telematics unit, the fob signals the nomadic device via its short-range communication link to initiate a global network communication for relaying the command or request to the telematics unit. If a command or data request communication initiated via the nomadic device cannot be completed due to inadequate network signal reception, the nomadic device signals the fob via its short-range communication link to initiate an RF communication for relaying the command or request to the telematics unit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a diagram of a fault tolerant vehicle information and control system according to this invention, including a vehicle-installed telematics unit, a wireless fob and a wireless nomadic device. 
           [0008]      FIG. 2A  is a flow diagram illustrating a communication sequence initiated by the wireless fob of  FIG. 1 , with manual path selection. 
           [0009]      FIG. 2B  is a flow diagram illustrating a communication sequence initiated by the wireless nomadic device of  FIG. 1 , with manual path selection. 
           [0010]      FIG. 2C  is a flow diagram illustrating a communication sequence initiated by the wireless fob of  FIG. 1 , with automatic path selection. 
           [0011]      FIG. 2D  is a flow diagram illustrating a communication sequence initiated by the wireless nomadic device of  FIG. 1 , with automatic path selection. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0012]    Referring to the drawings, and particularly to  FIG. 1 , the reference numeral  10  generally designates a fault tolerant vehicle information and control system including a wireless telematics unit  12  installed in vehicle  14 , a user-carried wireless portable fob  16 , and a user-carried nomadic personal communication device  18  such as a cell phone or PDA (referred to herein simply as nomadic device  18 ). In general, the system  10  is configured to support both medium-range RF communications and global network communications between telematics unit  12  and the user-carried fob  16  and nomadic device  18 . Communications between nomadic device  18  and telematics unit  12  can be relayed through the fob  16 , and communications between fob  16  and telematics unit  12  can be relayed through nomadic device  18 . Medium-range RF communications are supported by medium-range RF transceivers  20  and  22  in telematics unit  12  and fob  16 , respectively; global network communications are supported by network transceivers  24  and  26  in telematics unit  12  and nomadic device  18 , respectively, and a cellular antenna (or satellite) network  28 ; and relay communications are supported by short-range transceivers  30  and  32  in fob  16  and nomadic device  18 . The short-range transceivers  30  and  32  may be Bluetooth IEEE 802.11 gfb/aln, Near Field Communication (NFC), WiFi, or WiMax, for example. 
         [0013]    Within vehicle  14 , a communication bus  33  couples the transceivers  20  and  24  of telematics unit  12  to both a body and security controller  34  and an engine diagnostic system  36 . The body and security controller  34  interfaces with various vehicle systems and actuators such as a tire pressure sensing system  38 , door lock actuators  40 , supplemental restraint system  42 , and a security camera  44 . The engine diagnostic system  36  interfaces with the vehicle engine (not shown) and stores engine diagnostic and maintenance data that can be supplied to nomadic device  18  when requested. 
         [0014]    Fob  16  incorporates a conventional user interface, including depressible buttons  46  for signaling command functions such as door locking and unlocking, trunk unlatching, and alarm activation and deactivation. When a button  46  is depressed, the medium-range RF transceiver  22  within fob  16  establishes a bi-directional communication link with medium-range RF transceiver  20  within telematics unit  12  (as signified by the reference numeral  48 ) for authenticating the user and carrying out the corresponding command. Fob  16 , telematics unit  12 , and RF transceiver  22  can also constitute a passive entry system wherein the body and security controller  34  automatically locks or un-locks the vehicle doors via actuator  40  when the user-carried fob  16  crosses a prescribed distance threshold from the medium-range RF transceiver  20 . Preferably, fob  16  additionally includes a programmed controller (not shown) coupled to the transceivers  22  and  30  for routing communications as explained below. 
         [0015]    Nomadic device  18  is a conventional commercially-available cell phone or PDA, for example, that can be programmed with downloadable application software that regulates interactions between it, fob  16  and telematics unit  12 . The keypad  50  and display  52  provide a useful and familiar human-machine interface for issuing vehicle commands and receiving vehicle data, obviating the need for similar interface elements on fob  16 . 
         [0016]    Communications between telematics unit  12  and nomadic device  18  can be initiated by telematics unit  12  or by the user of nomadic device  18 . For example, the body and security controller  34  can be programmed to initiate a communication in response to the occurrence of a specified event such as high cabin temperature, a crash event, low tire pressure, unauthorized entry, low battery voltage, and so on. The communication uses the human machine interface of the nomadic device  18  to inform the user of the event, or to provide additional information including video and/or audio data from the vehicle  14 . If network signal is not available, telematics unit  12  can be programmed to transmit the information to fob  16  via the medium-range RF transceivers  20  and  22 , whereafter fob  16  will relay the information to nomadic device  18  via the short range wireless communication link  49 . A remote user can initiate a communication, for example, by simply depressing a button on the nomadic device  18  or fob  16 . The communication can be authenticated by the fob  16  (using a conventional rolling code, for example) or by the user (by entry of a PIN code or password, for example). 
         [0017]    The flow diagrams of  FIGS. 2A-2D  illustrate different user-initiated communication sequences. In  FIG. 2A , the communication sequence is initiated from fob  16 , with user path selection; and in  FIG. 2B , the communication sequence is initiated from nomadic device  18 , with user path selection. User path selection in this sense means that the user selects the communication path—by medium-range RF communication link  48  if fob  16  is used to initiate the communication, and by the global network communication link  54 ,  56  if nomadic device  18  is used to initiate the communication. In  FIG. 2C , the communication sequence is initiated from fob  16 , with automatic path selection; and in  FIG. 2D , the communication sequence is initiated from nomadic device  18 , with automatic path selection. Automatic path selection means that an alternate communication path is automatically established (if possible) when the user selected communication path is not available. 
         [0018]    In the communication sequence of  FIG. 2A , the user initiates a command from fob  16 , such as a door locking command, as indicated by block  60 . At block  62 , fob  16  determines if the vehicle  14  is within range for RF communication. If not, fob  16  provides an out-of-range signal to the user, as designated by block  64 ; this may be a visual or audible signal, depending on how fob  16  is equipped. If the vehicle  14  is in RF range, fob  16  proceeds to initiate a communication session via RF transceiver  22 , and exchanges security information with the RF transceiver  20  of telematics unit  12 , as indicated by blocks  66  and  68 . Telematics unit  12  then tests the validity of fob  16 , as designated by block  70 . If fob  16  is deemed to be invalid, telematics unit  12  ends the session as indicated at block  72 . If fob  16  is deemed to be valid, telematics unit  12  allows the communication to proceed and appropriately responds to the fob-initiated request or command, as indicated at blocks  74 ,  76  and  78 . As indicated at block  80 , the communication session can include more than one request or command, such as commands to lock doors and close windows, for example. When the last request has been processed, the communication session is ended as indicated at block  82 . 
         [0019]    The communication sequence of  FIG. 2B  is user-initiated via nomadic device  18 , as indicated at block  84 . In this case, the nomadic device  18  first determines if network service is available, as indicated at block  86 . If not, nomadic device  18  provides a “no-signal” indication to the user, as designated at block  88 . If network service is available, nomadic device  18  proceeds to initiate a network communication session to the network transceiver  24  of telematics unit  12 . The ensuing network communication sequence signified by blocks  90 ,  92 ,  94 ,  96 ,  98 ,  100 ,  102 ,  104  and  106  parallels the corresponding RF communication sequence of  FIG. 2A , and is not described again here. 
         [0020]    The flow diagram of  FIG. 2C  shows a preferred implementation of the fob-initiated communication sequence. Hence, blocks  108  and  110  of FIG.  2 C respectively correspond to blocks  60  and  62  of  FIG. 2A . Only here, if fob  16  determines that the vehicle  14  is out of range for RF communication, fob  16  signals nomadic device  18  via the short-range communication link  112  to initiate a network communication with transceiver  24  of telematics unit  12 , as indicated by block  114 . In other words, fob  16  uses nomadic device  18  to relay the fob-initiated request or command to telematics unit  12 . Thus, the communication sequence proceeds to block  90  of  FIG. 2B , as indicated by the circled numeral two in  FIG. 2C  and the corresponding circled numeral two in  FIG. 2B . 
         [0021]    Finally, the flow diagram of  FIG. 2D  shows a preferred implementation of the nomadic device initiated communication sequence. Hence, blocks  116  and  118  of  FIG. 2D  respectively correspond to blocks  84  and  86  of  FIG. 2B . Only here, if nomadic device  18  determines that there is no network signal, nomadic device  18  signals fob  16  via the short-range communication link  112  to initiate a RF communication with transceiver  20  of telematics unit  12 , as indicated by block  120 . In other words, nomadic device  18  uses fob  16  to relay the nomadic device initiated request or command to telematics unit  12 . Thus, the communication sequence proceeds to block  66  of  FIG. 2A , as indicated by the circled numeral one in  FIG. 2D  and the corresponding circled numeral one in  FIG. 2A . 
         [0022]    The above-described system  10  has a fault tolerant character in that there are different options for initiating vehicle information and control communications. For example, if the user misplaces fob  16 , or its internal battery fails, vehicle information and control communications can still be initiated using nomadic device  18 , and vice versa. Also, the system  10  may be configured to provide different levels of functionality. For example, while the automatic path selection described in reference to  FIGS. 2C-2D  is preferred, an advantage to the manual path selection option of  FIGS. 2A-2B  is that the nomadic device  18  requires no modifications, as described in the aforementioned U.S. patent application Ser. No. 12/150,872 (Attorney Docket No. DP-316582). Moreover, it is possible to configure the system  10  for automatic path selection for fob-initiated communications, but not nomadic device initiated communications, or vice versa, if desired. Many other variations are also possible, and it is intended that the invention not be limited to the disclosed embodiment, but that it have the full scope permitted by the language of the following claims.