Abstract:
A vehicle immobilization system ( 10 ) is coupled to a network system ( 20 ) and includes a vehicle that has a speed sensor ( 34 ) generating a vehicle speed signal, a telematics control unit ( 48 ) receiving and transmitting signals to and from the network ( 20 ), and a speed control module ( 72 ). An immobilization controller ( 30 ) is coupled to the speed sensor ( 34 ), the telematics control unit ( 48 ), and the speed control module ( 72 ). The immobilization controller ( 30 ) receives an immobilization signal from the network ( 20 ) and sets a maximum operating speed for the power train controller. When the vehicle speed signal is below the maximum operating speed, the immobilization controller reduces the maximum operating speed within the speed control module until a lower predetermined speed limit is met. The lower speed limit is preferably greater than zero so that some limited mobility of the vehicle may be achieved.

Description:
BACKGROUND OF INVENTION  
         [0001]    The present invention relates generally to theft deterrent devices for automotive vehicles, and more specifically, to an engine immobilization system that allows rapid recovery of a vehicle.  
           [0002]    Vehicle anti-theft systems typically sound an alarm upon the unauthorized entry into the automotive vehicle. Other anti-theft systems provide engine immobilization using an electronic circuit such as a transponder, which in addition to a cut key allows the engine to be started. Such systems are not effective to reduce carjacking or reduce risks in police pursuit. That is, once a thief obtains the keys for the vehicle the vehicle may be driven away. Also, many systems are capable of being bypassed and thus allow the vehicle to be driven away.  
           [0003]    Telematic systems are becoming popular items on motor vehicles. Telematic systems include a network connection to a satellite or cellular phone system that allows directions or the like to be obtained. Such systems typically operate in conjunction with a global positioning system.  
           [0004]    In a carjacking situation, it is desirable to let the thief drive away so that the proper authorities may apprehend the suspects. However, once away from the vehicle owner, the proper authorities have no means to restrict the operation of the vehicle.  
           [0005]    It would therefore be desirable to provide a system that increases the likelihood of vehicle recovery after a vehicle has been stolen.  
         SUMMARY OF INVENTION  
         [0006]    The present invention provides a system that increases the possibility of recovery using a centralized service provider that operates in connection with police or law enforcement intervention.  
           [0007]    In one aspect of the invention, a vehicle immobilization system is coupled to a network system and includes a vehicle that has a speed sensor generating a vehicle speed signal, a telematics control unit receiving and transmitting signals to and from the network, and a speed control module. An immobilization controller is coupled to the speed sensor, the telematics control unit, and the speed control module. The immobilization controller receives an immobilization signal from the network and sets a maximum operating speed for the power train controller. When the vehicle speed signal is below the maximum operating speed, the immobilization controller reduces the maximum operating speed within the speed control module until a lower predetermined speed limit is met. The lower speed limit is preferably greater than zero so that some limited mobility of the vehicle may be achieved.  
           [0008]    In a further aspect of the invention a method of operating a vehicle immobilization system comprising:receiving an immobilization signal;setting a maximum operating speed; and when the vehicle speed is below the maximum operating speed, reducing the maximum operating speed to the vehicle speed until the maximum operating speed is a predetermined lower speed limit.  
           [0009]    One advantage of the invention is that the system, once the lower speed limit has been reached, allows the vehicle to have limited mobility to prevent, for example, stopping in an undesirable location such as on a railroad track. Also, the system has safeguards to help insure proper use of the system.  
           [0010]    Other advantages and features of the present invention will become apparent when viewed in light of the detailed description of the preferred embodiment when taken in conjunction with the attached drawings and appended claims. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0011]    [0011]FIG. 1 is a block diagrammatic view of an immobilization system according to the present invention.  
         [0012]    [0012]FIG. 2 is a flow chart for immobilizing the vehicle according to the present invention.  
         [0013]    [0013]FIG. 3 is a flow chart for deactivating the system according to the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0014]    In the following figures the same reference numerals will be used to illustrate the same components. While specific components are mentioned in the following description, various alternatives will be evident to those skilled in the art. Such variations are not limited to those set forth below.  
         [0015]    Referring now to FIG. 1, an immobilization system  10  is illustrated having a vehicle  12 , a service provider  14 , a law enforcement agent  16 , and a vehicle owner  18 . The vehicle owner  18 , the law enforcement agent  16 , the service provider  14 , and the vehicle  12  may be interconnected with a network  20 . Network  20  may be various types and combinations of networks including a wireless cellular type connection, a satellite connection, public service telephone network, or private telephone network. The interface between vehicle owner  18  and law enforcement agent  16  may also be personal rather than through network  20 .  
         [0016]    Vehicle  12  has an immobilization controller  30  that controls the operation of the immobilization system  10  within the vehicle. Immobilization controller  30  is preferably microprocessor based. Although immobilization controller  30  is illustrated as a separate component, the immobilization controller  30  may be incorporated into or combined with various other controllers or control units not limited to those set forth herein.  
         [0017]    Immobilization controller  30  is programmed to operate using software to perform the method described below. Immobilization controller  30  is coupled to an ignition status sensor  32  that senses the status of the ignition. Ignition status sensor  32  may for example, be a separate sensor that senses voltage or an ignition switch position sensor. Of course, those skilled in the art will recognize that other types of ignition status sensors may be used.  
         [0018]    A vehicle speed sensor  34  is coupled to immobilization controller  30 . Vehicle speed sensor  34  may be one of a variety of types of speed sensors typically used in automotive vehicles. For example, a toothed wheel such as that used in anti-lock brake systems may be used. Other types of vehicle speed sensors may also be used including a transmission sensor and obtaining the vehicle speed from a communications bus within the vehicle. Vehicle speed sensor  34  generates a vehicle speed signal.  
         [0019]    Occupant sensors  36  are preferably also coupled to immobilization controller  30 . Occupant sensors  36  generate an occupant sensor signal indicative of the number of occupants of the vehicle. Occupant sensors  36  may be stand-alone sensors or may be incorporated into a restraint system of the present invention. Immobilization controller  30  may also be coupled to a tire pressure release actuator  38  that is coupled to one or more vehicle tires  40 . Tire pressure release actuator upon a command from immobilization controller  30  may release the tire pressure from tires  40 . Immobilization controller  30  is coupled to a telematics control unit  48 . Telematics control unit  48  includes a telematics controller  50  that is preferably microprocessor based. Telematics controller  50  is coupled to a transmitter  52  and a receiver  54 . Transmitter  52  and receiver  54  receive communication from network  20  through antenna  56 . A suitable antenna is used for the type of communications received. For example, antenna  56  may be configured to receive satellite signals, wireless cellular signals or the like.  
         [0020]    Telematics controller  50  may also be coupled to a microphone  58  and a speaker  60 . Microphone  58  receives voice signals and transmits them to telematics controller  50 , which may in turn transmit them through antenna  56 . A speaker  60  is also coupled to telematics controller. Speaker  60  broadcasts information within the vehicle, such as those received by receiver  54  through antenna  56 . Both microphone  58  and speaker  60  may be stand-alone units or may be incorporated into a hands-free cellular telephone set.  
         [0021]    Telematics controller  50  may also be coupled to another input device such as a keypad  62  or other data entry device.  
         [0022]    Telematics controller  50  may also be coupled to a global positioning system (GPS)  64 . GPS  64  may be coupled to a separate antenna  66  or through antenna  56 . GPS  64  generates a position signal of the vehicle and couples that to telematics controller  50 .  
         [0023]    Immobilization controller  30  is also coupled to a powertrain controller  70 . Powertrain controller  70  has a speed control module  72  therein. Powertrain controller  70  may be one of various types of controllers such as an engine controller or a combination engine and transmission controller. Powertrain controller  70  is also preferably microprocessor based. Immobilization controller  30  in conjunction with speed control module  72  may limit the speed of the vehicle to the vehicle speed sensed by vehicle speed sensor  34 . The speed control module, as will be further described below, may keep resetting the maximum speed of the vehicle to the vehicle speed as the vehicle speed falls below the maximum vehicle speed. The speed control module will limit the speed up until a lower speed limit such as five miles per hour to allow the vehicle to have a minimum amount of maneuverability.  
         [0024]    Service provider  14  includes a transmitter  74  for transmitting various information such as an immobilization signal to vehicle  12 . Service provider  14  also includes an operator interface  76 . Operator interface  76  may be coupled to a memory  78  and a peripheral device  80 . Service provider receives information from law enforcement agent  16  and determines the validity of the signal by a password stored in memory  78 . Operator interface  76  may then generate an immobilization signal in response to the law enforcement agent  16 .  
         [0025]    Law enforcement agent  16  has an agent identification  82  that is transmitted through network  20  to service provider  14 . The agent identification  82  may include information transmitted through service provider for verification such as the receiving officer&#39;s badge number and the accident report number. Of course, other information such as a law enforcement agent&#39;s password may also be required. Law enforcement agent  16  communicates the password from vehicle owner  18  to service provider  14  by way of network  20  which, as mentioned above, may include various means such as public service telephone network, wireless network, or satellite wireless network.  
         [0026]    Referring now to FIG. 2, a method of immobilizing the vehicle is provided. In step  100  the owner reports the vehicle stolen and provides the police or other law enforcement agent with their password. In step  102  the police or other law enforcement agent provide various agent identifications such as the badge number, accident report, and the vehicle owner&#39;s password to request vehicle immobilization. In step  104  the service provider through operator interface  76  validates the password. If the password is not validated in step  106 , step  108  cancels the immobilization. In step  106  if the password is valid, the service provider logs the badge number and report number in memory  78  and issues an immobilization signal or command through operator interface  76  through network  20  in step  110 . In step  112  the vehicle receives the immobilization command and validates the immobilization command. This is done in the immobilization controller  30  described above through the telematics control unit  48 . If the vehicle determines that the immobilization command is not valid in step  114 , step  116  cancels the immobilization command. A predetermined code, for example, must be received by vehicle  12  to validate the immobilization command. In step  114  if the immobilization command is valid, step  118  is performed in which it is determined whether or not the vehicle is running. If the vehicle is not running in step  118  the telematics control unit prevents the vehicle from starting in step  120 . In step  122 , the telematics control unit sends the current location received from GPS  64  to the service provider  14  which may in turn provide the information to a law enforcement agent  16 . In step  124 , by providing the position of the vehicle the local authorities may take possession of the vehicle that is not able to start.  
         [0027]    Referring back to step  118 , if the vehicle is running the telematics control unit sends the current location from GPS  64  to service provider  14  which in turn provides the position signal to law enforcement agent  16  through network  20 .  
         [0028]    In step  128  the service provider may establish a voice connection through telematics control unit and speaker  60  to the current operators of the vehicle. The service provider instructs the current vehicle operator to speak the password, which is received by microphone  58  and transmitted through transmitter  52  to service provider  14 . In step  130 , if the password is a valid password the immobilization is canceled in step  132 . In step  130 , if the password is not valid the telematics control unit sends a message to the speed control module  72  through immobilization controller  30  to prevent the vehicle from accelerating. That is, the maximum vehicle speed is set to the current vehicle speed. As the current vehicle speed is reduced, the maximum vehicle speed is also reduced and not allowed to increase. Thus, the maximum vehicle speed is reduced down to a predetermined limit that is greater than zero. This allows the vehicle to still be somewhat maneuvered but at extremely low speed such as five miles per hour. In step  136  the law enforcement agent  16  may also establish a voice connection through service provider  14  to the vehicle operator. Also in step  138  the tire pressure relief actuator  38  may be controlled through immobilization controller  30  at the request of a law enforcement agent if the thief tries to outrun the police officers.  
         [0029]    Referring now to FIG. 3, once the vehicle has been recovered by the law enforcement agent, the law enforcement agent notifies the service provider and provides the agent identification such as the badge number, accident report, the password, and a request for deactivation in step  140 . The information coincides with the information of step  102  in FIG. 2. In step  142  the service provider validates the password. If the password is not validated in step  144 , step  146  is executed in which deactivation is canceled. In step  144  if the password is a valid password the service provider records the badge number, report number, or other agent identification and sends a deactivation signal to the vehicle  12  in step  148 . In step  150 , the vehicle receives the deactivation signal through telematics control unit  48  and determines whether the deactivation command is valid in block  152 . If the command is not valid in step  152 , step  154  is performed in which the deactivation is canceled. In block  152  if the deactivation command is valid, step  156  is executed in which the immobilization is deactivated and the vehicle may be operated normally. The deactivation command may be validated by determining various parameters previously provided from the service provider that is stored within a memory and the immobilization controller or telematics control unit.  
         [0030]    As can be seen by the above description, the present invention advantageously allows the vehicle to be driven away from a vehicle operator but, when activated, the vehicle will eventually slow to a very slow speed. This will allow the law enforcement agents to quickly recover the vehicle since vehicle position is provided to the service provider.  
         [0031]    While particular embodiments of the invention have been shown and described, numerous variations and alternate embodiments will occur to those skilled in the art. Accordingly, it is intended that the invention be limited only in terms of the appended claims.