(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2006/0145811 A1
`Nantz et al.
`(43) Pub. Date:
`Jul. 6, 2006
`
`US 20060145811A1
`
`(54) DUAL RANGE VEHICLE REMOTE
`
`(52) U.S. Cl.
`
`........................................ .. 340/5.72; 340/5.64
`
`(76)
`
`Inventors: John Nantz, Brighton, MI (US);
`Matthew Honkanen, Royal Oak, MI
`(US); Bruce D. Conner, Dearborn, MI
`(US)
`
`Correspondence Address:
`MACMILLAN SOBANSKI & TODD LLC
`720 WATER STREET
`TOLEDO, OH 43604 (US)
`
`(21) App], No;
`
`11/030,658
`
`(22)
`
`Filed?
`
`Jam 6: 2005
`
`Pubhcatlon Classlficatlon
`
`(51)
`
`Int CL
`H04Q 1/00
`G08C 19/00
`
`(2006.01)
`(200601)
`
`(57)
`
`ABSTRACT
`
`A method and system are disclosed for operating a controller
`of and a RKE system to provide for short distance functions
`h
`bl f
`k
`f b
`h
`d-
`f
`
`include receiving a desired type of radio frequency signal;
`actuating a high gain mode of a receiver of the controller;
`detecting a message from an acceptable remote keyless entry
`transmitter; decoding a function code portion of the mes-
`sage; changing the receiver from the high gain mode to a
`lower gain mode if the function code is not a long distance
`function; decoding a remaining portion of the message;
`determining if the remaining portion of the message was
`decoded properly; and performing the requested function if
`the remaining portion of the message was decoded properly.
`
`1
`
`ASSA 1022
`
`1
`
`ASSA 1022
`
`

`
`Patent Application Publication
`
`Jul. 6, 2006 Sheet 1 of 3
`
`US 2006/0145811 A1
`
`54
`
`Preamble
`
`Frame 1
`
`g
`
`/g
`
`/g
`
`Message ID
`
`Function Code Rolling Code Bits 4/
`
`64
`
`55
`
`68
`
`70
`
`2
`
`

`
`Patent Application Publication
`
`Jul. 6, 2006 Sheet 2 of 3
`
`US 2006/0145811 A1
`
`
`
`Sample RF data
`
`'
`
`Is
`
`preamble signal
`detected?
`
`
`
`
`100
`
`102
`
`104
`
`106
`
`
`
`Switch from polling mode to full
`run mode with high gain
`
`Receive message and begin to
`decode
`
`108
`
`sync portion of mesage
`detected?
`
`ls
`
`110
`
`Yes
`
`
`
`Decode message ID and
`function code
`
`3
`
`

`
`Patent Application Publication
`
`Jul. 6, 2006 Sheet 3 of 3
`
`US 2006/0145811 A1
`
`114
`
`Decrease
`receiver
`code for a long distance
`
` function?
`sensitivity
`
`
`
`
`
`Is function
`
`Decode remaining portion of
`message
`
`124
`
`Decode next
`
`message
`
`
`
`112
`
`116
`
`118
`
`120
`
`Was
`
`the message decoded
`properly?
`
`
`
`Was
`
`
`
`additional message
`received?
`
`
`
`Perform requested function-
`
`126
`
`4
`
`

`
`US 2006/0145811 A1
`
`Jul. 6, 2006
`
`DUAL RANGE VEHICLE REMOTE
`
`BACKGROUND OF INVENTION
`
`[0001] The present invention relates to remote keyless
`entry types of systems employed with automotive vehicles.
`
`[0002] Remote keyless entry systems are commonly used
`with automotive vehicles today. Such systems are including
`a wider range of functions that can be performed by the
`remote keyless entry system. For example, not only are the
`conventional lock, unlock, trunk release, and panic functions
`available, but also new functions such as remote engine
`start.
`
`[0003] For certain functions, such as remote engine start,
`it is desirable to allow these functions to be performed while
`the operator is a greater distance from the vehicle than for
`some of the conventional functions. For example, one may
`wish to allow for the remote engine start, door lock, and
`panic alarm functions to be operable when the key fob is as
`far away from the vehicle as two hundred meters. To obtain
`this long rage functionality, the remote keyless entry system
`can be designed to operate at this greater distance.
`
`[0004] Having the greater range of operation for the
`remote keyless entry system, however, may be undesirable
`for certain other remote keyless entry functions. One may
`wish to avoid inadvertently releasing the trunk if the trunk
`release button on the key fob is pressed when one is at this
`long range distance since he will not see or hear the trunk
`release. Moreover, one may not wish to inadvertently unlock
`the vehicle doors when at this longer range since one may be
`out of sight of the vehicle and thus not realize that the doors
`are unlocked. Accordingly, it may be undesirable for door
`unlock or trunk release functions to be operable from the
`same two hundred meter distance. Of course, the shorter
`range functions are still desirable for the remote keyless
`entry system, so operators may wish for these short-range
`functions to be operable only when the operator actuates the
`key fob at a more conventional range of, for example, about
`fifty meters or less.
`
`Some have attempted to overcome this drawback
`[0005]
`by designing their remote keyless entry systems to try and
`detect the distance that the key fob is from the vehicle when
`the button is pressed, and then determine what function, if
`any, to perform based on this detected distance. This may be
`attempted by using received signal strength indicator (RSSI)
`circuitry. But due to environmental conditions, such as
`ambient radio frequency noise, this type of method can be
`very unrepeatable—that is, the range is not always consis-
`tently and accurately determined. Such inaccuracy may be
`undesirable for vehicle operators with these types of remote
`keyless entry systems. Thus, it is desirable to have a remote
`keyless entry system that allows for operation of both
`long-range and short-range functions, while overcoming the
`drawbacks of the prior art.
`
`SUMMARY OF INVENTION
`
`[0006] An embodiment of the present invention contem-
`plates a method of operating a controller of a remote keyless
`entry system in a vehicle comprising the steps of: receiving
`a desired type of radio frequency signal; actuating a high
`gain mode of a receiver of the controller; detecting a
`message from an acceptable remote keyless entry transmit-
`
`ter; decoding a function code portion of the message;
`changing the receiver from the high gain mode to a lower
`gain mode if the function code is not a long distance
`function; decoding a remaining portion of the message;
`determining if the remaining portion of the message was
`decoded properly; and performing the requested function if
`the remaining portion of the message was decoded properly.
`
`[0007] An embodiment of the present invention also con-
`templates a method of determining whether to perform a
`remotely requested vehicle function transmitted via an RF
`signal from a remote transmitter to a vehicle, the method
`comprising the steps of: actuating a button on the remote
`transmitter within a predetermined distance from the vehicle
`to cause the transmission of the RF signal, with the RF signal
`having a preamble portion and a message portion; receiving
`the RF signal with a RKE system in the vehicle; actuating a
`high gain mode of the RKE system; determining whether the
`remotely requested vehicle function in the message portion
`is a short distance function; changing the receiver to a lower
`gain mode if the remotely requested vehicle function is the
`short distance function; decoding a remaining portion of the
`message portion; and performing the remotely requested
`vehicle function if the remaining portion of the message
`portion is decoded properly.
`
`[0008] An embodiment of the present invention further
`contemplates a dual range vehicle remote that includes a key
`fob and a remote keyless entry (RKE) system. The key fob
`includes a plurality of buttons, each adapted for indicating a
`desired remote function, and a transmitter capable of trans-
`mitting a signal having a message portion indicative of the
`desired function when one of the plurality of buttons is
`actuated. The RKE system may include a receiver capable of
`receiving the signal, and a controller for setting the RKE
`system in high gain mode, determining if the desired func-
`tion in the message portion is a short distance function,
`changing the RKE system to a lower gain mode if the
`desired function is a short distance function, decoding a
`remaining portion of the message portion, and performing
`the desired function if the remaining portion of the message
`portion is decoded properly.
`
`[0009] An advantage of an embodiment of the present
`invention is that, for certain remote keyless entry functions
`where it is desirable to operate from a long distance, these
`functions may operate at these longer distances, while other
`short distance functions are disabled at such long distances.
`Thus, inadvertent actuation of short distance functions from
`a long distance can be avoided.
`
`[0010] A further advantage of an embodiment of the
`present invention is that the ability to disable the short
`distance functions when the key fob is at a long distance may
`be performed in a consistent and repeatable manner.
`
`[0011] An additional advantage of an embodiment of the
`present invention is that no received signal strength indicator
`(RSSI) or other distance calculating technology is required
`in the operation of this invention.
`
`BRIEF DESCRIPTION OF DRAWINGS
`
`[0012] FIG. 1 is a schematic representation of the vehicle
`and remote keyless entry system, and the ranges at which the
`system operates, in accordance with an embodiment of the
`present invention.
`
`5
`
`

`
`US 2006/0145811 A1
`
`Jul. 6, 2006
`
`[0013] FIG. 2 is a block diagram representing an example
`of a radio frequency transmission from a key fob, in accor-
`dance with an embodiment of the present invention.
`
`a short distance function if it is currently activated (i.e., one
`is pressing the alarm button 46 requesting deactivation of the
`alarm).
`
`[0014] FIG. 3 is a flow chart showing remote keyless
`entry controller operation in accordance with an embodi-
`ment of the present invention.
`
`DETAILED DESCRIPTION
`
`[0015] FIG. 1 schematically shows a vehicle 30 having a
`remote keyless entry system, indicated generally at 32. The
`remote keyless entry (RKE) system 32 includes a controller
`34 in communication with a receiver 36. The controller 34
`
`may be in communication with systems that carry out the
`desired RKE functions, such as a door lock/unlock actuator
`(not shown), a vehicle horn and headlights (not shown), an
`engine ignition system (not shown), and/or a trunk release
`mechanism (not
`shown). These systems will not be
`described in any detail since they are known to those skilled
`in the art. Moreover, the controller 34 and receiver 36 may
`be integral or separate components, and may be comprised
`of various combinations of hardware and software, as is
`known to those skilled in the art.
`
`[0016] Akey fob 38 includes a set ofbuttons, such as, for
`example, lock 40, unlock 42, engine start 44, alarm 46, and
`trunk release 48. Of course, additional or different remote
`functions may be performed by the key fob 38, if so desired.
`For example, power door open and close functions may be
`included on the key fob. The key fob 38 also has a power
`source and other electronic circuitry, including a transmitter
`50, which is capable of transmitting a radio frequency (RF)
`signal 52 in response to the actuation of one of the buttons
`on the key fob 38. The details of the transmitter 50 and other
`electronic circuitry (not shown) and power source (not
`shown) of the key fob 38 will not be discussed in detail
`herein since they are known to those skilled in the art.
`
`[0017] FIG. 1 also provides an illustration of different
`ranges/distances at which the desired RKE functions may be
`operable. That is, when the key fob 38 is within a first
`range/distance D1, it is desirable that the RKE system 32
`receives the RF signal 52 from the transmitter 50 and that all
`of the RKE functions are operable. Between the first range/
`distance D1 and a second range/distance D2, it is desirable
`that the RKE system 32 only perform long distance func-
`tions, while not enabling short distance functions. The actual
`ranges/distances D1, D2 employed by the system can be set
`as desired for a particular vehicle, but may be, for example,
`fifty meters for the shorter range/distance D1 and two
`hundred meters for the longer range/distance D2.
`
`[0018] Long distance functions are those that are desired
`to operate up to the limits of about range/distance D2, while
`short distance functions are those that are desired to only
`operate up to the limits of about range/distance D1. For
`example, door lock, engine start, and alarm may be long
`distance functions while door unlock and trunk release may
`be short distance functions. As an alternative, a function may
`be applied as a long or short distance function depending
`upon whether it
`is being activated or deactivated. For
`example, if so desired, the alarm function may be treated by
`the RKE system 32 (in FIG. 1) as a long distance function
`if it is currently deactivated (i.e., one is pressing the alarm
`button 46 requesting to activate the alarm), but be treated as
`
`[0019] FIG. 2 illustrates a block diagram representing an
`example of the RF signal 52 from the key fob 38 (of FIG.
`1). This RF signal 52 may employ a common format for
`transmitting an RF signal from the key fob 38. The RF signal
`52 may include a preamble portion 54, followed by a first
`frame 56, a second frame 58 and a third frame 60. The
`preamble portion 54 may be just a detectable type of RF
`transmission at a desired frequency and coding, which may
`not be specific to a particular key fob, but that the RKE
`system 32 (in FIG. 1) will recognize as requiring it to wake
`up from its power saving polling mode to a full run mode.
`The first frame 56 preferably contains a first complete
`message 62, with the second and third frames 58, 60 just
`comprising redundant messages (not illustrated) the same as
`the first complete message 62.
`
`[0020] The first complete message 62 preferably contains
`a synchronizing (sync) portion 64, followed by a message
`identifier (ID) portion 66, a function code portion 68, and a
`rolling code bits portion 70. The sync portion 64 merely
`assures that the RKE system 32 has the correct timing for
`reading the RF signal 52 properly. The message ID portion
`66 and function code portion 68 contain information relating
`to the particular function being requested, (i.e., the function
`to be performed based on the button that was pressed on the
`key fob 38). The rolling code bits portion 70 relates to the
`encryption being employed. The messages in the second and
`third frames 58, 60 will just repeat this same information
`contained in the first frame 56. While the RF signal 52 is
`shown with three frames 56, 58, 60 each containing the same
`redundant messages 62, the system can be configured so that
`a greater or lesser number of redundant frames 56, 58, 60
`can be transmitted with each press of a button on the key fob
`38, if so desired.
`
`[0021] FIG. 3 illustrates a method of operating the con-
`troller 34 (of FIG. 1) in the vehicle 30 as it receives a RF
`signal 52 (such as that illustrated in FIG. 2). The controller
`34 typically starts in a polling mode, which reduces power
`consumption during long periods of inactivity. In the polling
`mode,
`it samples RF data, block 100,
`to determine if a
`preamble is detected, block 102. If the sampling of the RF
`data does not detect a preamble, then the sampling of RF
`data in a polling mode continues. If a preamble is detected,
`then the controller 34 switches from a polling mode to full
`run mode with high gain, block 104. The message is then
`received and begins to be decoded, block 106. If no sync
`portion of the message is detected, then the controller returns
`to a polling state and again samples RF data.
`[0022]
`If, on the other hand, a sync portion of the message
`is detected, the message ID and function code are decoded,
`block 110. If the function code is for a long distance
`function, the remaining portion of the message is decoded,
`block 116. If the function code is not for a long distance
`function, the receiver sensitivity is decreased, block 114, and
`then the remaining portion of the message is decoded, block
`116. Thus, for short distance functions,
`the message is
`decoded in a low gain mode. Examples of RKE functions
`that may be long distance or short distance were discussed
`above relative to FIG. 1.
`
`[0023] The switching from high to low gain mode
`accounts for the distance from the vehicle 30 that the key fob
`
`6
`
`

`
`US 2006/0145811 A1
`
`Jul. 6, 2006
`
`38 is when the RKE request is transmitted. Presumably, if
`the rest of the message becomes corrupted after the receiver
`36 is switched to the low gain mode, the user with the key
`fob 38 must be standing farther away from the vehicle 30
`than the range/distance D1, so the short distance function
`should not be carried out. If, in the low gain mode, the rest
`of the message is successfully decoded, then the user with
`the key fob 38 is likely within the range/distance D1 and the
`function should be carried out. Of course, if the function is
`a long range function,
`then the rest of the message is
`decoded in high gain mode, in which case, it is likely to be
`decoded properly if the user with the key fob 38 is within the
`range/distance D2. The levels for high and low gain, and the
`difference between the two, will depend upon various fac-
`tors, including the actual distances one wishes for ranges/
`distances D1 and D2. The setting of levels for high and low
`gain to achieve the desired results are know to those skilled
`in the art and so will not be discussed further herein.
`
`Moreover, while only two levels of gain are employed to
`distinguish only short and long distance functions, there may
`be three levels of gain employed to distinguish short,
`medium and long distance functions, if so desired.
`
`to
`[0024] Consequently, a determination is made as
`whether the remaining portion of the message was decoded
`properly, block 118. If it was not decoded properly, a check
`is made to determine if an additional message was received,
`block 122. If an additional message was received,
`this
`additional message is decoded, block 124, and a determi-
`nation is made as to whether this message was decoded
`properly, block 118. The additional messages may be those
`contained in the redundant frames 58, 60 (illustrated in FIG.
`2). This continues until a message is decoded properly or
`until no additional messages are received. If a message is
`decoded properly, then the requested function is performed,
`block 120, and the routine ends, block 126. If there are no
`additional messages and no messages were decoded prop-
`erly, then the routine ends, block 126, without performing
`any function.
`
`[0025] While certain embodiments of the present inven-
`tion have been described in detail, those familiar with the art
`to which this invention relates will recognize various alter-
`native designs and embodiments for practicing the invention
`as defined by the following claims.
`
`What is claimed is:
`
`1. A method of operating a controller of a remote keyless
`entry system in a vehicle comprising the steps of:
`
`(a) receiving a desired type of radio frequency signal;
`
`(b) actuating a high gain mode of a receiver of the
`controller;
`
`(c) detecting a message from an acceptable remote key-
`less entry transmitter;
`
`(d) decoding a function code portion of the message;
`
`(e) changing the receiver from the high gain mode to a
`lower gain mode if the function code is not a long
`distance function;
`
`(f) decoding a remaining portion of the message;
`
`(g) determining if the remaining portion of the message
`was decoded properly; and
`
`(h) performing the requested function if the remaining
`portion of the message was decoded properly.
`2. The method of claim 1 further including the steps of:
`
`(i) determining if an additional message was received;
`
`(j) decoding the additional message, if the additional
`message was received;
`
`(k) determining if the additional message was decoded
`properly, if the additional message was received; and
`
`(l) performing the requested function if the additional
`message was decoded properly.
`3. The method of claim 2 further including the steps of:
`
`(m) determining if a second additional message was
`received;
`
`(n) decoding the second additional message, if the second
`additional message was received;
`
`(o) determining if the second additional message was
`decoded properly, if the second additional message was
`received; and
`
`(p) performing the requested function if the second addi-
`tional message was decoded properly.
`4. The method of claim 1 wherein step (a) is further
`defined by operating the controller in a polling state.
`5. The method of claim 1 wherein step (a) is further
`defined by receiving a preamble signal.
`6. The method of claim 1 wherein step (e) is further
`defined by the long distance function being a remote engine
`start function.
`
`7. The method of claim 1 wherein step (e) is further
`defined by the long distance function being a door lock
`function.
`
`8. The method of claim 1 wherein step (e) is further
`defined by the long distance function being a vehicle alarm
`activation function.
`
`9. A method of determining whether to perform a
`remotely requested vehicle function transmitted via an RF
`signal from a remote transmitter to a vehicle, the method
`comprising the steps of:
`
`(a) actuating a button on the remote transmitter within a
`predetermined distance from the vehicle to cause the
`transmission of the RF signal, with the RF signal
`having a preamble portion and a message portion;
`
`(b) receiving the RF signal with a RKE system in the
`vehicle;
`
`(c) actuating a high gain mode of the RKE system;
`
`(d) determining whether the remotely requested vehicle
`function in the message portion is a short distance
`function;
`
`(e) changing the receiver to a lower gain mode if the
`remotely requested vehicle function is the short dis-
`tance function;
`
`(f) decoding a remaining portion of the message portion;
`and
`
`(g) performing the remotely requested vehicle function if
`the remaining portion of the message portion is
`decoded properly.
`
`7
`
`

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`US 2006/0145811A1
`
`Jul. 6, 2006
`
`10. The method of claim 9 further including the steps of:
`
`(h) determining if the RF signal includes an additional
`message portion;
`
`(i) decoding a remaining portion of the additional mes-
`sage portion, if the RF signal includes the additional
`message portion; and
`
`(j) performing the remotely requested vehicle function if
`the remaining portion of the additional message portion
`is decoded properly.
`11. The method of claim 10 further including the steps of:
`
`(k) determining if the RF signal includes a second addi-
`tional message portion;
`
`(1) decoding a remaining portion of the second additional
`message portion, if the RF signal includes the second
`additional message portion; and
`
`(m) performing the remotely requested vehicle function if
`the remaining portion of the second additional message
`portion is decoded properly.
`12. The method of claim 9 wherein step (d) is further
`defined by the short distance function being a door unlock
`function.
`
`13. The method of claim 9 wherein step (d) is further
`defined by the short distance function being a trunk release
`function.
`
`14. A dual range vehicle remote comprising:
`
`a key fob including a plurality of buttons, each adapted for
`indicating a desired remote function, and a transmitter
`capable of transmitting a signal having a message
`portion indicative of the desired function when one of
`the plurality of buttons is actuated; and
`
`a RKE system including a receiver capable of receiving
`the signal, and a controller for setting the RKE system
`
`in high gain mode, determining if the desired function
`in the message portion is a short distance function,
`changing the RKE system to a lower gain mode if the
`desired function is a short distance function, decoding
`a remaining portion of the message portion, and per-
`forming the desired function if the remaining portion of
`the message portion is decoded properly.
`15. The dual range vehicle remote of claim 14 wherein
`one of the plurality of buttons is a remote engine start button,
`and the RKE system is adapted to stay in the high gain mode
`if the desired function is a remote engine start function.
`16. The dual range vehicle remote of claim 14 wherein
`one of the plurality of buttons is a door unlock button, and
`the RKE system is adapted to change to the lower gain mode
`if the desired function is a door unlock function.
`
`17. The dual range vehicle remote of claim 14 wherein
`one of the plurality of buttons is a door lock button, and the
`RKE system is adapted to stay in the high gain mode if the
`desired function is a door lock function.
`
`18. The dual range vehicle remote of claim 14 wherein
`one of the plurality of buttons is a remote engine start button,
`the RKE system is adapted to stay in the high gain mode if
`the desired function is an alarm function and the alarm
`
`function is not currently activated.
`19. The dual range vehicle remote of claim 18 wherein the
`RKE system is adapted to change to the lower gain mode if
`the desired function is an alarm function and the alarm
`
`function is currently activated.
`20. The dual range vehicle remote of claim 14 wherein
`one of the plurality of buttons is a trunk release button, and
`the RKE system is adapted to change to the lower gain mode
`if the desired function is a trunk release function.
`
`8