Abstract:
A vehicle antitheft system and method detects the starting of a vehicle and starts a first timer. If the first timer times out without the system having detected a first predetermined sequence, the system actuates a vehicle system warning signal and starts a second timer. If the second timer times out without detecting a second predetermined sequence, which may be the same as or different from the first predetermined sequence, the system disables the vehicle. The system may send vehicle location information to a monitoring service or the like. The vehicle remains disabled until the antitheft system is reset.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Technical Field 
         [0002]    The present invention relates generally to the field of antitheft devices, and more particularly to a vehicle antitheft system and method that includes implicit authorized operator authentication. 
         [0003]    2. Description of the Related Art 
         [0004]    Vehicle theft is a major problem. There exist several systems that attempt to prevent vehicle theft or track the vehicle after it has been stolen. The theft deterrent devices and systems are usually visible or placed in locations that are well known to professional thieves. The vehicle tracking devices may be defeated by experienced thieves. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention provides a vehicle antitheft system and method. Embodiments of the present invention detect the starting of a vehicle. The system starts a first timer in response to the starting of the vehicle. The system is programmed to detect a first predetermined sequence of vehicle operator actions and a second predetermined sequence of vehicle operator actions, which may be the same as the first predetermined sequence. If the first timer times out without the system having detected the first predetermined sequence, the system actuates a vehicle system warning signal and starts a second timer. Examples of vehicle system warning signals include low fuel, high temperature, low oil pressure, check engine, and the like. If the second timer times out without detecting the second predetermined sequence, the system disables the vehicle. Examples of ways in which the system may disable the vehicle include disabling the ignition and/or fuel systems of the vehicle. The system may send vehicle location information to a monitoring service or the like. The vehicle remains disabled until the antitheft system is reset. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further purposes and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, where: 
           [0007]      FIG. 1  is a block diagram of an embodiment of a system according to the present invention; 
           [0008]      FIG. 2  is a flow chart of an embodiment of pressing according to the present invention; and, 
           [0009]      FIG. 3  is a flow chart of an embodiment of predetermined sequence detection processing according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0010]    Referring now to the drawings, and first to  FIG. 1 , a system according to the present invention is designated generally by the numeral  100 . System  100  includes an antitheft computer  101  programmed according to the present invention. Antitheft computer  101  may be any suitable computing device using any suitable architecture running any suitable operating system, with suitable device drivers and interfaces to the components of system  100 . Antitheft computer may be a separate dedicated computer installed in a vehicle or an onboard computer adapted to perform other operations besides the theft prevention according to the present invention. 
         [0011]    Input devices  103  may be sensors or controllers for various devices and systems in the vehicle. Input devices  103  may include such things as turn signals, door locks, side window controllers, vehicle lights, windshield washers, air-conditioning controls, audio controls, and the like. Generally, input devices  103  may include any device in the vehicle that the driver of the vehicle can operate. 
         [0012]    As will be explained in detail hereinafter, antitheft computer  101  is programmed to look for a pre-determined sequence of actuations of various input devices  103 . A predetermined sequence may consist of any sequence of driver actuations of any monitored systems in the vehicle. For example, a predetermined sequence may consist of turning on the left turn signal, followed by lowering the right rear side window, followed by raising the right rear side window, followed by turning off the left turn signal. Another predetermined sequence may consist of actuating the window washers, followed by turning the air-conditioning fan to high, followed by turning on fog lamps, followed by setting the air-conditioning system to automatic. 
         [0013]    System  100  includes a program interface  105 . Program interface  105  is used to put antitheft computer  101  into a programming mode. Program interface  105  may be a switch located in a concealed location in the vehicle. Alternatively, program interface  105  may be implemented through a standard diagnostic computer interface connection in the vehicle. 
         [0014]    In one embodiment of the present invention, when program interface  105  is operated to put antitheft computer  101  into programming mode, any previous predetermined sequence is cleared and an operator executes a predetermined sequence. After executing the predetermined sequence, program interface  105  is operated to save the predetermined sequence and put antitheft computer  101  into operating mode. 
         [0015]    As will be explained in detail hereinafter, when the vehicle is started, antitheft computer  101  looks for the program to predetermined sequence. Antitheft computer  101  from ignition system  107  to determine when the vehicle has been started. If antitheft computer  101  sees the predetermined sequence within a predetermined period after the vehicle is started, antitheft computer  101  allows the vehicle to continue to operate. If antitheft computer  101  does not see the predetermined sequence within the predetermined period, antitheft computer  101  disables the vehicle. 
         [0016]    In one embodiment, antitheft computer  101  may disable the vehicle by turning off the ignition system  107 . In other embodiments, antitheft computer  101  may disable the vehicle by disabling fuel system  109 . According to the present invention, the vehicle remains disabled until antitheft computer  101  is reset. Antitheft computer may be reset by operating a reset control associated with program interface  105 . 
         [0017]    Prior to disabling the vehicle, antitheft computer  101  actuates one or more vehicle system warning signals  111 . Actuation of a vehicle system warning signal  111  signals the vehicle driver that the vehicle is about to be disabled. An authorized driver will know that he or she must execute the programmed predetermined sequence in order to prevent the vehicle from becoming disabled. An unauthorized driver will think there is something wrong with the vehicle. Examples of vehicle system warning signals include low fuel, low oil pressure, high cooling system temperature, check engine, and the like. 
         [0018]    System  100  may include a GPS receiver  113  and a cellular telephone  115  coupled to antitheft computer  101 . When antitheft computer  101  disables the vehicle, it queries GPS receiver  113  for the vehicle&#39;s position and transmits that position to a security monitoring service, or the like. Cellular telephone  115  may also be used to reset antitheft computer  101  after the vehicles has been disabled. For example, the vehicle owner or security monitoring service employee may call cellular telephone  115  and enter a reset code, thereby resetting antitheft computer  101 . 
         [0019]      FIG. 2  is a flow chart of processing according an embodiment of to the present invention. When the system determines, at decision block  201 , that the ignition switch is turned on, the system determines, at decision block  203 , if the vehicle is disabled. If so, the system waits for a reset signal, at decision block  205 . If the vehicle is disabled, it will remain disabled until the system is reset. When the system is reset, the system enables the vehicle and turns off the vehicle system warning signal or signals, all as indicated at block  207 . 
         [0020]    If, as determined at decision block  203 , the vehicle is not disabled, or after reset as determined at decision block  205 , the system sets timers, at decision block  209 . The preferred embodiment of the invention includes a first timer and a second timer. The system starts the first timer, at block  211 . If, as determined at decision block  213 , the program the predetermined sequence is entered before the first timer times out, at decision block  215 , the system resets the first timer, at block  217 , and processing ends. Thereafter, the vehicle will continue to run normally. If the first timer times out, at decision block  215 , before the predetermined sequence is entered, the system displays the vehicle system warning signal and starts the second timer, at block  219 . If, as determined at decision block  221 , the predetermined sequence is entered before the second timer times out, at decision block  223 , the system turns off the vehicle system warning signal and resets the timers, at block  225 . Thereafter, the vehicle continues to run normally. If the second timer times out at decision block  223  before the sequences entered at decision block  221 , the system disables the vehicle and calls the vehicle&#39;s location to a monitoring service, at block  227 . 
         [0021]      FIG. 3  is a flow chart of one embodiment of sequence detection processing according to the present invention. Antitheft computer  101  is receiving signals from each monitored driver operated system in the vehicle. In the embodiment of  FIG. 3 , antitheft computer  101  is looking for a particular sequence of five actions. If, as determined at decision block  301 , the first action is detected, the system waits for the second action. If, as determined at decision block  303 , the next action detected is not the second action of the sequence, processing returns to decision block  301  and starts over. If, as determined at decision block  303 , the second action is detected, the system waits for the third action. If, as determined at decision block  305 , the next action detected is not the third action, processing returns to decision block  301 . If, as determined at decision block  305 , the third action is detected, the system waits for the fourth action. If, as determined at decision block  307 , the next action detected is not the fourth action, processing returns to decision block  301 . If, as determined at decision block  307 , the next action detected is the fourth action, the system waits for the fifth action. If, as determined at decision block  309 , the next action is not the fifth action, processing returns to decision block  301 . If, as determined at decision block  309 , a next action detected is the fifth action, the system returns sequence entered, at block  311 , and sequence detection processing ends. Thus, in the embodiment of  FIG. 3 , the operator must perform the programmed sequence in order without performing any non-sequence actions. Those skilled in the art will recognize that processing according to  FIG. 3  is only one example of sequence detection processing. For example, a more rigorous processing scheme might end if after having performed the first action the operator makes a mistake. The example in  FIG. 3  gives the operator the opportunity to correct a mistake by starting over, while making it unlikely that an unauthorized operator could randomly perform actions in and defeat the system. 
         [0022]    From the foregoing, it will be apparent to those skilled in the art that systems and methods according to the present invention are well adapted to overcome the shortcomings of the prior art. While the present invention has been described with reference to presently preferred embodiments, those skilled in the art, given the benefit of the foregoing description, will recognize alternative embodiments. Accordingly, the foregoing description is intended for purposes of illustration and not of limitation.