Patent Publication Number: US-2009231094-A1

Title: Multiple vehicle remote keyless entry apparatus

Description:
BACKGROUND 
     The present disclosure relates, in general, to remote keyless entry systems and, particularly, to vehicle remote keyless entry systems. 
     Wireless key fobs are widely used for vehicle access and to remotely control vehicle functions, such as locking or unlocking doors, remote engine starting, flashing of emergency horns and lights, as well as to control, locate and provide information feedback between the driver and the vehicle. 
     Typically, one remote keyless entry (RKE) transmitter is used to control only one specific vehicle&#39;s functions. Each vehicle has its own separate fob with authentication codes, even if two vehicles owned by the same user are from the same vehicle manufacturer. This forces the user to either carry two separate key chains, each with a fob, or one large key chain with two fobs. Having to deal with two separate key chains is inconvenient for the driver. For example, if the driver grabs the wrong fob when he needs access to the other vehicle, significant frustration can be experienced. The one large key chain, on the other hand, is difficult for the user to carry in a pocket or purse, thus making this solution also undesirable. 
     It will be desirable to provide an RKE system which enables a single RKE fob to be used to control multiple vehicles or remote keyless devices. 
     SUMMARY 
     A method and apparatus for activating a device control function from a portable remote entry device including a control to control activation of the device control functions by a controller configured for receiving wireless signals from the remote entry device and activating the selected vehicle control device. 
     The method includes the steps of activating control functions from a portable remote entry device incorporating a control to control activation of the control functions by a controller configured for receiving wireless signals from the remote entry device, storing a plurality of unique device identification codes in a memory in the remote entry device, selecting by the remote entry device one of the unique device identification codes, transmitting the selected unique identification code and a device control function selected by the remote entry device to a transmitter on the remote entry device, and transmitting the selected identification code and the control function to the controller for implementation of the selected control function. 
     The method further includes the steps of storing a plurality of unique transmission encryption algorithms in the memory of the remote entry device, and using one of the unique encryption algorithms to generate a unique transmission code. 
     The method may include the step of providing indication on the remote entry device of a selected one of the transmission codes. 
     The method may further include the step of providing the indicator with unique indications corresponding to each of the distinct identification codes stored in the memory. 
     The method may further include the step of constructing the remote entry device as a fob for a vehicle. 
     An apparatus for remotely activating device control functions, such as vehicle, garage door, and home functions, includes a controller adapted to be coupled to the device and operable to generate signals to control a device function, a portable remote entry device carrying at least one control function input, a control and a memory storing transmission encryption algorithms unique to each of a plurality of devices, a select input on the remote entry device for selecting one of the plurality of devices for signal transmission. The remote entry device control transmits a signal to the controller upon selection of one of the control function inputs, the signal including the unique identification code corresponding to the selected one of a plurality of devices. 
     The apparatus may further include an indicator carried on the remote entry device responsive to the control for providing a unique indication corresponding to the selected one of the plurality of devices for signal transmission by the control. The control of the remote entry device includes a program mode to learn new device transmission encryption algorithms. 
     The apparatus may further include a memory for storing a plurality of unique transmission encryption algorithms, each algorithm generating a unique device transmission code. 
     The apparatus may further include at least one LED displaying different colors or other Human Machine Interface indicators corresponding to each of the plurality of selectable devices. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       The various features, advantages and other uses of the present invention will become more apparent by referring to the following detailed description and drawing in which: 
         FIG. 1  is a pictorial representation of a vehicle remote keyless entry system and single fob for two vehicles; 
         FIG. 2  is a block diagram of the control circuitry of the fob; 
         FIG. 3  is a flow chart of the normal operation mode of the fob; and 
         FIGS. 4A and 4B  are flow charts depicting the program mode of the fob. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawing, and to  FIGS. 1 ,  2  and  3  in particular, there is depicted a plurality of vehicles, with two vehicles  10  and  11  shown by way of example. Each vehicle  10  and  11  has a remote keyless entry or RKE apparatus  12  mounted therein. A single wireless key fob  14  is associated with both RKEs  12  and is identifiable by a plurality of unique message and/or frequency matches to enable the fob  14  to transmit signals to both the RKEs  12  which are recognized by each RKE  12  as being valid for control functions in the vehicle  10  or  11 , exclusively. 
     As shown in detail in  FIG. 2 , the fob  14  includes a control  46 , which may be a processor based control executing a control program stored in a memory  48 . One or more input members or buttons  18  are mounted on the housing  16  of the fob  14 . The input members, such as switches or buttons  18  are each associated with a particular vehicle function, such as locking or unlocking the vehicle doors and/or trunk or hatch, lowering the vehicle windows, remotely starting the vehicle engine, flashing the vehicle&#39;s horn and/or lights, etc. A visual display, not shown,  62  may also be mounted in the fob housing  16  to display vehicle status or button  18  selection information. 
     It will be understood that the shape of the fob housing  16 , the number and functions designated by the buttons  18 , and the provision or non-provision of the display can be modified for any application; and any fob circuitry, housing shape, number and control function assigned to each button  18  may be employed 
     A power supply, such as a battery  40 , is contained in the housing  16  for powering the components of the fob  14  as shown in  FIG. 2 . A transmitter, a transmitter/receiver, a transceiver or a transponder  50  is mounted in the housing  16  for transmitting data signals generated by the control  46  in response to depression or activation of one of the buttons  18 . The transmitter  50  has a frequency of operation between 300 MHz to 450 MHz, for example only. Multiple transmitters/receivers may be implemented to support vehicles which use different operating frequencies and/or other transmission parameters, such as ASK vs FSK, for example. 
     The user depresses or activates one of the buttons  18  associated with the desired vehicle function that the user wishes to initiate. The input signal from the button  18  wakes up or activates the processor in the control  46  which outputs a data signal or data stream to the transmitter  50 . The data stream may include a data preamble, the actual vehicle function command, i.e., unlock vehicle doors, etc., an optional rolling code for vehicle to vehicle security, and possibly one or more check bits. This signal is sent by the transmitter  50  through an antenna  52  to the RKE  12  where it is received by an RKE receiver through an antenna. The signal is demodulated by a vehicle RKE access controller which may also a microprocessor based controller. The controller outputs a signal to a vehicle function control device or to a vehicle body computer which implements the desired vehicle function. 
     To enable a single fob  14  to communicate with multiple vehicles  10  and  11 , the fob  14  is provided with the ability to transmit two or more unique transmission IDs. The unique transmission ID will be generated through a distinct encryption algorithm each time a function command button  18  on the fob  14  is depressed or activated. The control  46  supports multiple encryption algorithms that will create independent codes for each respective messages. By supporting multiple encryption algorithms and/or transmitter frequencies, this method not only has the ability to transmit commands for different vehicles from the same manufacturer or vehicle supplier, but it also can be used across multiple manufacturers and supplier combinations. 
     The fob  14  has a human machine interface that conveys both the current mode of the fob  14  as well as a select input member or button  60  to enable the user to change the current mode. This interface also enables vehicle service personnel to change the current mode and select the proper encryption algorithm while programming the fob  14  to support additional vehicles. 
     An indicator means  62  is employed in the fob  14  to provide the current mode of one of the vehicles  10  and  11  during normal operation. For example only, the indicator  62  could be a multicolored LED where one color, such as red, represents the vehicle  10  and a different color, such as green, represents the second vehicle  11  other indicator means, such as multiple LEDs, one designated for each vehicle  10  or  11 . 
     As shown in  FIG. 2 , the memory  48  includes a plurality of memory spaces  48 A- 48   n  which define the discrete or independent encryption algorithms for each of the vehicles  10  and  11 . Additional memory spaces may be provided for storing programming encryption algorithms for other vehicles, garage door operators, home control functions, and other remote controlled devices 
     The normal operation mode of the fob  14  is shown in  FIG. 3 . Once initially activated by insertion of the battery  40  in step  70 , the fob  14  operation is defined by a default memory space, such as space one, shown by reference number  48 A. 
     When the select input member or button  60  is pressed in step  72 , the indicator  62  in step  74  indicates the current vehicle  10  or  11  which is selected for signal transmission. If the select button  60  is pressed again within a time window preset time period, step  76 , the control  48  checks if a new memory space  48 A- 48   n  is valid in step  78  as containing a programmed encryption algorithm for another vehicle. 
     If the new memory space is valid, the control  46  shifts to a new memory space for new vehicle fob operations in step  80 . The indicator  62  now indicates in step  82  the new vehicle  10  or  11  which has been selected. The fob  14 , in step  84 , is now configured for communication with the desired vehicle  10  or  11 . Any of the input members or buttons  18  can be depressed to cause activation of the selected vehicle function in the selected vehicle  10  or  11 . 
     The indicator or LED  62  could display the color associated with the current selected vehicle  10  or  11  whenever one of the command input buttons  18  is pressed. This would enable the user or driver to immediately determine that he or she is transmitting command or control signals to the desired vehicle  10  or  11 . 
     The same select button  60  and indicator  62  can be used during a program mode or cycle of the fob  14 . In this mode, the indicator or LED  62  would change to a different color, number of flashes, or other visual or audio output methods to indicate the memory space  48 A- 48   n  which is about to be programmed. Once placed in the program mode, the indicator or LED  62  would indicate the current selected encryption algorithm selected by flashing a predetermined light sequence, such as a series of time-spaced short flashes to indicate vehicle  10  or a series of time-spaced, pair of quick pulses to indicate the other vehicle  11 . 
     When the select button  60  is depressed, a message transmission to the vehicle  10  or  11  by the fob  14  will not occur and thus there will be no advancement of the associated unique vehicle ID rolling code. The rolling codes for each of the unique transmission IDs would only change when the message for the specific ID is transmitted. The fob  14  will next transmit the appropriate message of the indicated ID when the subsequent function button  18  presses i.e., lock, unlock, etc. 
     The program mode used by service personnel is depicted in  FIGS. 4A and 4B . 
     The service personnel would also use the select button  60 . In one aspect, the service personnel would use the select button  60  to change between the memory spaces  48 A- 48   n  associated with each possible vehicle. For example, the fob  14  could support four different vehicles. Hence, the memory  48  could have four separate memory spaces  48 A., etc., one for each vehicle. 
     The same select button  60  would also be used to select the proper encryption algorithm to be associated with the memory space  48 A- 48   n.  Since the encryption algorithms are a set formula, the memory spaces  48 A- 48   n  could be used to store the rolling code generated by the algorithm. The encryption algorithms themselves can be stored in the memory  48  typically in a ROM portion of the memory  48 . With proper hardware and software interfaces, the memory area used to contain the encryption algorithms could also be implemented with a programmable type of memory, such as flash memory, so that upgrades to the algorithms may be implemented after the fob  14  is delivered to the customer. 
     Referring now to  FIGS. 4A and 4B , when entering the program mode, the select button  60  can be depressed for a predetermined amount of time, such as ten seconds, to activate the program mode shown in step  100 . The indicator  62  then indicates in step  102 , the selected program mode for vehicle  10  or  11 . The select button  60  is then pressed within a predetermined time, such as within five seconds, as shown in step  104 . 
     The indicator  62  by changing colors or number of flashes or other output methods indicates the current memory space  48 A- 48   n  which is selected in step  106 . The select button  60  is then pressed within a predetermined time window, such as five seconds, as shown in step  108 . 
     If the select button  60  is again pressed within the preset time window or period, the control  46  changes the selected memory space  48 A- 48   n  to the next memory space in step  110 . The indicator  62  then changes color or state to indicate the next memory space in step  112 . 
     Referring back to step  108 , if the select button  60  is not pressed within the time window after the initial memory space is selected as indicated by the indicator  106 , the indicator  106  will indicate that the algorithm program mode has been selected by a sequence of light flashes in step  114 . The indicator  62  in step  116  also indicates by a series of flashes, for example, or a sequence of light color changes, that access to the selected algorithm program mode has been allowed. The indicator  62  indicates the current algorithm selected in step  118 . If the select button  60  is pressed within a time window, within such as five seconds, in step  120 , the control  46  changes the algorithm to the next algorithm in step  122 . The indicator  62  then indicates the next algorithm selected in step  124 . 
     Referring back to step  120 , if the select button  60  is not pressed within the time window, the control  46  assigns the selected stored algorithm to the current memory space  48 A- 48   n  in step  126 . The indicator  62  will then indicate the selected memory space  48 A- 48   n  and algorithm which had been selected in step  128  and control returns to the normal operation mode.