Abstract:
The present invention relates to a button starting system for a vehicle which is able to stably start up by using an LF antenna installed in the vehicle in an emergency of a smart key. According to the system, the necessity of installation of a key holder can be removed.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims under 35 U.S.C. §119(a) the benefit of Korean Patent Application No. 10-2008-85060 filed on Aug. 29, 2008, the entire contents of which are incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to an emergency starting system and method of vehicle, more particularly, to a technology which is capable of normally operating a smart key including a key FOB in an emergency, by using an LF (Low Frequency) antenna provided in the vehicle. 
         [0003]    Immobilizer systems are used to prevent vehicle theft through the communication between a start key and the vehicle. 
         [0004]    According to a typical immobilizer system for a vehicle, an encryption code is generated from a key FOB or a smart key, the encryption code is transmitted to the smart key controller installed in the vehicle for authentication, and if it is authenticated, the vehicle is started. The authentication is performed by comparing the received encryption code with an ID which has been stored in advance. 
         [0005]    In the immobilizer system, the key FOB or the smart includes a built-in transponder storing a security program related to the prevention of vehicle theft and an ID code. The transponder performs the function of generating the encryption code. 
         [0006]    Referring to  FIG. 1 , the operation of a conventional button starting system will be illustrated. 
         [0007]    If a driver presses a button to start a vehicle, the input of the start button is sensed through a button input unit  2 . When the input of the start button is sensed, a smart key controller  6  controls an LF antenna to output an LF wakeup signal. The LF wakeup signal is received in the transponder of a smart key  4 . The transponder transmits to an RF response signal including the ID of the smart key in response to the LF wakeup signal. An RF receiver  10  transmits the ID of the smart key which is loaded in the received RF response signal to the smart key controller  6 . If the ID coincides with the ID code which has been registered in advance in the smart key  4 , the smart key controller  6  transmits a starting permission message to an engine starting controller  12 . The engine starting controller  12  operates an engine (not shown) if the starting permission message is received. 
         [0008]    In the meantime, if the battery which is built in a smart key  4  is exhausted, the smart key  4  is unable to generate the RF response signal according to the LF wakeup signal which is transmitted from an LF antenna  8 . In the present invention, as described above, the state where the smart key  4  is unable to generate the RF response signal according to the LF wakeup signal due to the battery exhaustion is defined as “emergency” state. 
         [0009]    In an emergency state, after controlling the LF antenna  8  to transmit the LF wakeup signal, the smart key controller  6  waits for the ID reception of the smart key through the RF receiver  10 . However, if the RF response signal is not transmitted from the smart key  4  for a predetermined time, the smart key controller  6  transits to an emergency starting state. 
         [0010]    After the transition to the emergency starting state, if the smart key  4  is inserted into a key holder  14  which is provided in the vehicle separately, the smart key  4  is charged with a magnetic force generated from the key holder  14  and outputs a signal including an encrypted transponder code. After the key holder  14  extracts the encrypted transponder code from the received signal, the validity of the ID included in the extracted transponder code is determined so that the result is transmitted to the smart key controller  6 . If the ID is determined to be valid, the smart key controller  6  transmits the starting permission message to the engine starting controller  12  so that the engine is started. Typically, the key holder  14  is installed in the vehicle around the start button  1 . 
         [0011]    The installation position has to be considered in the vehicle interior design and the installation is an element to increase overall vehicle manufacturing costs. 
         [0012]    The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. 
       SUMMARY OF THE INVENTION 
       [0013]    The present invention provides an emergency starting system capable of stably starting a vehicle by using an LF antenna installed inside the vehicle, which obviates the necessity of setting up a key holder in the vehicle. 
         [0014]    In one aspect, the present invention provides an emergency starting system of a vehicle including a button starting system. The system may include a smart key controller an emergency alarm unit. The smart key controller, when the smart key is working properly, controls the operation of engine of the vehicle to start in conjunction with a smart key when the button is pressed. On the other hand, when the smart key is in an emergency state, the smart key controller operates the smart key by transmitting an LF wakeup signal having an improved transmission power through an LF antenna installed inside the vehicle, authenticates the smart key through an LF response signal received from the smart key and controls the operation of the engine according to the authentication result. 
         [0015]    The emergency alarm unit functions to notify, under the control of the smart key controller, the emergency state of the smart key. 
         [0016]    In another aspect, the present invention provides an emergency starting method of a vehicle including a button starting system. The emergency starting method may comprise the steps of: (a) transmitting an LF wakeup signal with improved transmission power through an LF antenna installed inside the vehicle, when an emergency of a smart key is sensed; (b) notifying a driver of the emergency of the smart key; (c) performing authentication of the smart key by using an LF response signal transmitted from the smart key through the LF antenna; and (d) operating an engine in the case of successful authentication of the smart key. 
         [0017]    The above and other features and advantages of the present invention will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated in and form a part of this specification, and the following Detailed Description, which together serve to explain by way of example the principles of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    The above and other features of the present invention will now be described in detail with reference to certain exemplary embodiments thereof illustrated by the accompanying drawings which are given hereinafter by way of illustration only, and thus are not limitative of the present invention, and wherein: 
           [0019]      FIG. 1  is a block diagram of a conventional button starting system. 
           [0020]      FIG. 2  is a diagram illustrating a smart key holder and a start button of a conventional button starting system. 
           [0021]      FIG. 3  is a block diagram of an emergency starting system of a vehicle including a button starting system according to an embodiment of the present invention. 
           [0022]      FIG. 4  is a detailed configuration diagram of an LF antenna driving unit that is illustrated in  FIG. 3 . 
           [0023]      FIG. 5  is a flowchart that illustrates an emergency starting method of a vehicle including a button starting system according to an embodiment of the present invention. 
       
    
    
       [0024]    It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various preferred features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use in the environment. 
       DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0025]    Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the attached drawings 
         [0026]      FIG. 3  is a block diagram of an emergency starting system of a vehicle including a button starting system according to an embodiment of the present invention. 
         [0027]    The transponder of a smart key  30  is charged from an LF wakeup signal received from an LF antenna  32 . When the charged voltage reaches the operating voltage of the transponder, the smart key  30  transmits an LF response signal in which an encrypted transponder code information is loaded. 
         [0028]    The LF antenna  32  is installed at the vicinity of a cup holder inside the vehicle. The LF antenna  32  functions to transmit the LF wakeup signal to the transponder under the control of a smart key controller  40  and extract the encrypted transponder code information from the LF response signal to transmit to the smart key controller  40 . 
         [0029]    An RF receiver  34  receives an RF response signal transmitted from the smart key  30  which changes to a steady-state, extracts an encrypted ID information from the received RF response signal and transmits the extracted the encrypted ID information to the smart key controller  40 . 
         [0030]    The smart key controller  40  controls the LF antenna  32  in an emergency so that the LF wakeup signal is transmitted to the smart key  30 , and performs the transponder authentication on the smart key  30  based on the encrypted transponder code information which is transmitted from the LF antenna  32 . In the case when the transponder is successfully authenticated, a starting permission message is transmitted to an engine starting controller  52 . 
         [0031]    As shown in  FIG. 3 , the smart key controller  40  may comprise an LF antenna driving unit  44  and a MICOM  42 . 
         [0032]    The MICOM  42  performs an overall control in the smart key controller  40 . In particular, it controls the LF antenna driving unit  44  so that the LF wakeup signal is transmitted through the LF antenna  32  or the LF antenna  32  goes into a reception waiting state. 
         [0033]    A button input unit  50  transmits a button input signal to the smart key controller  40  when the start button is pressed down by a user. 
         [0034]    The engine starting controller  52  starts an engine (not shown) when a starting permission message is transmitted from the smart key controller  40 . 
         [0035]    A relay box  54  forms a relay to supply electric power to the whole vehicle, supplying the operating voltage to a cluster  56  under the control of the smart key controller  40 . In the state where the cluster  56  is operating by the voltage supplied from the relay box  54 , it notifies an emergency starting state or an emergency starting failure state to the driver under the control of the smart key controller  40 . According to a specification of the cluster  56 , the emergency starting state or the emergency starting failure state can be outputted with a character type or a ramp type. 
         [0036]    A voice output unit  57  outputs a voice message according to the place where the smart key  30  should be placed under the control of the smart key controller  40 , for example, “It is an emergency starting mode. Please move the smart key to the vicinity of cup holder”. 
         [0037]    The detail configuration of the LF antenna driving unit  44  illustrated in  FIG. 3  is shown in  FIG. 4 . 
         [0038]    As shown in  FIG. 4 , the LF antenna driving unit  44  includes power control means  46 ,  48  each of which controls the supply of electric power to the LF antenna  30  under the control of the MICOM  42 . 
         [0039]    More particularly, the LF antenna driving unit  44  includes a first power control means  46  to vary the voltage supplied to a first connection line between the LF antenna  30  and the MICOM  42  or to block the supply of the voltage, and a second power control means  48  to bypass a second connection line between the LF antenna  30  and the MICOM  42  to ground. In the present invention, the first power control means  46  and the second power control means  48  may comprise a transistor TR. By controlling the current applied to the base of the transistor TR corresponding to the first power control means  46 , the MICOM  42  can control the voltage applied to the LF antenna  30  through the first connection line. 
         [0040]    Using such configuration features, the MICOM  42  can control the energy transmission power of the LF antenna  30 . The transponder charging time of the smart key  30  can be controlled according to the energy transmission power. The first connection line is connected to the + end of the LF antenna  30 , whereas the second connection line is connected to − end of the LF antenna  30 . 
         [0041]    As described, if the smart key operates normally, the MICOM  42  provides a reference voltage corresponding to the voltage which is generally provided for the immobilizer communications to the LF antenna  30 . On the other hand, if the smart key is in an emergency state, the MICOM  42  controls the first power control means  46  so that a voltage higher than the reference voltage may be applied to the LF antenna  30 . 
         [0042]    The operation of an emergency starting system of a vehicle including a button starting system according to an embodiment of the present invention will be illustrated with reference to a flowchart illustrated in  FIG. 5 . 
         [0043]    At step S 2 , the smart key controller  40  determines whether a driver gets in a vehicle, and controls the LF antenna driving unit  44  so that a voltage is supplied to the LF antenna  30  when it is determined that the driver gets in the vehicle. In this process, the MICOM  42  of the smart key controller  40  controls the LF antenna driving unit  44  so that the first and the second power control means  46 ,  48  are turned on and the voltage is supplied to the LF antenna  30 . The determination of whether a driver gets in a vehicle can be made by, e.g., a sensing signal according to the opening and closing of a door. 
         [0044]    At step S 4 , the LF antenna  32  transmits the LF wakeup signal to the smart key  30 . 
         [0045]    At this time, if the smart key  30  is operating normally, the smart key  30  generates the RF response signal and transmits it so as to respond to the LF wakeup signal. If the smart key  30  is not operating normally (i.e., in an emergency state), the smart key  30  is unable to respond to the LF wakeup signal. 
         [0046]    At step S 6 , the smart key controller  40  determines whether the RF response signal is received. If it is determined that the RF response signal is received (YES at S 6 ), a normal button starting control is performed (S 8 ). The term “normal button starting control” is used herein to mean that an engine is controlled to start through an engine starting controller if authentication of a smart key is successful. Since the related technology is well known to a person skilled in the art, the detailed description thereof is omitted. 
         [0047]    On the other hand, if it is determined that the RF signal is not received, the smart key controller  40  operates a timer to determine whether a certain time has elapsed in a state in which the RF response signal is not received (S 10 ). 
         [0048]    If it is determined that the RF response signal is not received for a certain time, the smart key controller  40  changes to an emergency starting mode (S 12 ), notifying the driver that an emergency starting mode is turned on (S 14 ). 
         [0049]    At step S 14 , the smart key controller  40  controls the relay box  54  to supply the operating voltage to the cluster  56  and/or the voice output unit  57 , and commands the cluster  56  and/or the voice output unit  57  to output an emergency starting alarm message, so that the emergency starting alarm message is delivered visually, aurally, or both. As described above, the voice message, for example, “It is an emergency starting mode. Please move the smart key to the vicinity of cup holder” can be outputted through the voice output unit  57 . Through such notification, the driver can move the smart key  30  to a specific location guided by the cluster  56  (for example, the vicinity of cup holder or cluster) or other places. 
         [0050]    In the case the emergency starting alarm message is ordered to be outputted, for instance, the cluster  56  can output a corresponding emergency starting alarm message with a character style, or with a lamp style according to the performance. 
         [0051]    The smart key controller  40  may supply power to the LF antenna  32  until the LF response signal is received from the smart key  30 , so that the LF wakeup signal for the power transmission is transmitted through the LF antenna  32 . The smart key controller  40  may block the power supply of the LF antenna  32  so that the LF antenna  32  changes to a reception waiting state (S 18 ). 
         [0052]    While the LF wakeup signal, a magnetic force control, is transmitted from the LF antenna  32 , the transponder of the smart key  30  is charged until it reaches its operating voltage. When the charging of the operating voltage is completed, the transponder of the smart key  30  generates the LF response signal in which the encrypted transponder TP code information is included and transmits the LF response signal. 
         [0053]    At step S 18 , the MICOM  42  controls the current amount applied to the base of the first power control means  46  to increase the voltage applied to the LF antenna  30  through the first connection line, while turning the base of the second power control means  48  on to bypass the voltage of the second connection line to ground. 
         [0054]    At step S 20 , the smart key controller  40  determines whether the LF response signal is received through the LF antenna  32 . Step S 18  is performed repeatedly until the LF response signal is received. That is, step S 18  is periodically performed when the transponder of the smart key  30  is charged. Therefore, the LF wakeup signal is periodically transmitted from the LF antenna  32 . 
         [0055]    If it is determined that the LF response signal is received (S 20 ), the smart key controller  40  analyzes the encrypted transponder code information which is included in the received LF response signal and determines whether it is identical to the transponder code information which has been stored in advance (S 22 ). 
         [0056]    If it is determined that the transponder code information transmitted from the smart key  30  is identical to the transponder code information stored in advance, it is determined as a successful authentication (S 24 ) so that the starting permission message is transmitted to the engine starting controller  52  and operations are terminated (S 26 ). 
         [0057]    On the other hand, if it is determined that they are not identical, it is determined as an authentication failure (S 24 ) and operations are terminated. In another embodiment of the present invention, if the authentication fails, an authentication failure message can be indicated on the cluster  56  so that the driver is notified. 
         [0058]    It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.