Abstract:
Vehicle theft deterrence is affected by requiring the entry of an enabling code to prevent disablement of vehicle operation. System operational variables may be programmed by operators. The system is substantially integrated with existing vehicle control systems.

Description:
[0001]     This application claims the benefit of U.S. Provisional patent application No. 60/670,046, filed Apr. 11, 2005. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Technical Field  
         [0003]     The invention relates to theft deterrent systems for commercial vehicles and more particularly to a theft deterrent system integrated with existing vehicle control systems.  
         [0004]     2. Description of the Problem  
         [0005]     Medium and heavy duty trucks often transport valuable or hazardous cargo. This makes these vehicles targets for thieves. Unfortunately, truck electrical wiring is relatively simple compared to passenger cars. In addition, most medium and heavy duty trucks do not have locking steering columns or transmissions. Not having to defeat such devices reduces the time and effort required of thieves to steal a medium or heavy duty truck. It is a relatively simple matter on many vehicles simply to “slimjim” the door lock and hot wire the key switch, defeating the basic security procedure of removing the ignition key and locking the vehicle.  
         [0006]     After market devices designed to interrupt the ignition or engine crank circuit are known. These devices may require a hidden switch be depressed or some electrical feature such as headlights or the turn signal be switched on before engine cranking is tried. Experienced thieves and other well informed criminals can normally spot such systems quickly as they are not integral to the truck electrical system. This factor contributes to making the devices easier to defeat. Where such a device malfunctions due to failure of the device or poor installation, it can render the vehicle inoperative and make it difficult for regular service personnel to correct on account of lack of familiarity with the device. Such devices can prevent or delay emergency workers from starting and moving a vehicle, as may be necessary where a vehicle hauling flammable cargo is in the vicinity of open flames.  
         [0007]     One example of a third party, after market device, which provides an add-on circuit module, includes a series of switches into which the driver must type a numeric code before the park brake is released. If this is not done the engine is stopped by opening the ignition switch power feed through a relay. This device includes operational modes that are problematic. For example, the anti-theft code must be reentered every time the park brake is released or the engine is restarted. A flustered driver may be temporarily unable to reenter the code under time pressure.  
         [0008]     Any theft deterrent system which simply prevents the engine from cranking should also be capable of maintaining memory through the low voltages associated with engine cranking. This can require an expensive power supply.  
       SUMMARY OF THE INVENTION  
       [0009]     According to the invention there is provided a vehicle theft deterrent system. The vehicle theft deterrent system includes a combination entry system for the entry of enabling codes. A vehicle body computer connected to the combination entry system provides for checking the validity of entered combinations. An engine controller implements an engine torque output control program. A communication link between the vehicle body computer and the engine controller provides for messages sourced exogenous to the engine controller for specifying an engine output torque. An ignition circuit is activated by a key. A disable relay in the ignition circuit, having a control input, may be used to disable the ignition circuit regardless of the position of the key. The vehicle body computer has a control output coupled to the control input of the disable relay for controlling the state of the disable relay. The vehicle body computer is responsive to input of an invalid code for sourcing messages for limiting engine output torque rather than disabling the ignition system, permitting local operation of the vehicle.  
         [0010]     In its preferred embodiment, the present theft deterrent system is implemented using a six-pack of switches, a relay, minimal wiring and modification of software executed on a vehicle electrical system control module (ESC)/body computer. The feature provides a means to limit vehicle mobility once the vehicle is started. The feature is usable with both manual and automatic transmissions. If the engine is running, and the park brake is released or the vehicle is moved greater than 3 MPH without the proper anti-theft code entered, the body computer can instruct the engine controller to limit engine output to a fraction of its normal maximum. In order to prevent such derating, the driver is required to enter an anti-theft code each time the vehicle is started or when the park brake is released. The code may be entered at any time once the engine is running. However, if the park brake is released or the vehicle has been started with the park brake NOT set and then driven over 3 MPH, the driver has a specific time to enter the proper anti-theft code. The Anti-theft (enabling) code may be any code between 0000001 and 9999999. All digits of the code are to be entered, even if there are leading zeros. Audible and visual indicators are provided to indicate the status of the code entering sequence and position in the engine shut down sequence.  
         [0011]     The engine may be derated and shut down. Engine derating is used as a secondary method in conjunction with the shut down method. To provide shut down capability a normally closed relay is placed in series with the ignition relay that is under control of the ESC through a relay driver in the cab and placed under the control of the electrical system controller. The ESC is readily programmed to issue control instructions to the relay in response to absence or failure of the anti-theft code to conform to the proper code. The instruction may be issued immediately or after a delay. Failure of the instruction is readily determined from signals from the engine controller, in which case, engine output may be restricted as a fall back position.  
         [0012]     Additional effects, features and advantages will be apparent in the written description that follows.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]     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 objects 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, wherein:  
         [0014]      FIG. 1  is a block diagram of a vehicle controller area network control system adapted to implement the anti-theft system of the present invention.  
         [0015]      FIG. 2  is a simplified circuit schematic illustrating one aspect of the invention relating to disabling the ignition circuit.  
         [0016]      FIG. 3  is a simplified flow chart illustrating operation of the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0017]     Referring now to the figures and in particular to  FIG. 1 , a controller area network  10  such as used on a commercial vehicle is set out. Controller area network  10  has as foundational elements a programmable body computer (or Electrical System Controller)  30  based on a microprocessor  72  and memory  74 . Memory  74  may in turn include both volatile and non-volatile sections (not shown). Microprocessor  72  communicates with other parts of the programmable body computer  30  over a conventional bus. Among the other parts of the computer are input/output devices for handling network communications including a controller area network (CAN) interface  50  and a SAE J1708 interface  70 . The J1708 interface  70  provides for attachment to a six-pack switch bank  26 . Body computer  30  provides an array of drivers  28  for the direct control of discrete devices, including, as described below, an energization source for controlling a relay in a vehicle&#39;s ignition circuit. The CAN interface  50  and associated network are preferably implemented in accord with the SAE J1939 protocol.  
         [0018]     Switch pack  26  is a standard device and provides six rocker switches  27 A-F. Rocker switches  27 A-F are configured as three position devices, center stable and momentary switch action type (up and down). Five of the switches  27 B-F are labeled with the numbers 0 through 9, two digits each to a switch, and disposed in a way as to associate one digit with up action and the remaining digit with down action. A sixth switch  27 A may be illuminated under the control of body computer  30  as a status indicator and provides means for clearing codes to be entered using the pack. Codes of between 00000001 and 99999999 are allowed, entered in sequence beginning from the left.  
         [0019]     A representative control system is described here, however those skilled in the art will recognize that alternative arrangements are possible. The CAN interface  50  connects to a plurality of system controllers including a gauge cluster  14 , an anti-lock brake system controller  19 , a transmission controller  16  and an engine controller  20 . Any of these controllers may in turn be connected to one or more sensors or packages of sensors associated with the specific controller. The gauge cluster controller  14  controls an auditory alarm  24  used in one embodiment of the invention. ABS controller  19  collects data from wheel rotation sensors  33  which are used to determine skidding. A drive shaft road speed sensor  17  coupled to the output of the transmission  18  has an output connected to an engine controller  20 , which is another of the controllers connected to the J1939 compliant bus of the controller area network. A collection of engine sensors is represented by an engine sensor package  21 , which is also connected to the engine controller  30 . Engine sensor package  21  includes an engine tachometer, an air intake temperature gauge (providing a reasonable reading of ambient temperature), coolant temperature sensors, and engine oil temperature, level and dielectric constant sensors. Engine controller  20  also provides control over fuel injectors which determine the amount of fuel delivered to the engine  22  and the resulting power and torque output of the engine. An off board programming device  60  connected to the J1939 over a programming interface connector  31  can be used to allow an operator to program variables used in implementing the invention. Parameters such as the delay before onset of vehicle operation limitations, the code to be used, etc. can be changed. Vehicle body computer  30  is also connected to a park brake position sensor  71 .  
         [0020]     Controller area networks are well known in the art and the SAE (Society of Automotive Engineers) J1939 standard is widely employed. The controller area network provides a communication path by which vehicle speed is reported for the ESC body computer  30  to read and over which ESC body computer  30  can issue torque (limiting) requests to be read by the engine controller  20 .  
         [0021]     Referring now to  FIG. 2 , the present invention works by limiting engine torque output, which can be implemented in software, and by disabling the vehicle ignition circuit  200 , which is done using an anti-theft relay  212  located between a vehicle ignition key switch  214  and a cab ignition relay  216 . Torque limiting is also used to prevent the system from being circumvented by a thief defeating the anti-theft relay  212 . Key switch  214  is shown in its ignition position, providing a hot signal to the input pin of relay  212 . Relay  212  is shown closed, but opens in response to a signal generated by the ESC  30 . The activation signal for opening relay  212  is activate driver transistor  28 K of array  28  into conduction bringing connector pin  210  low. With relay  212  open relay  216  is cut off and opens, which interrupts the connection to the remainder of the ignition circuit  218 . ESC  30  provides the appropriate control signal on connector pin  210  in response to the vehicle speed messages, the value of the operator input on switch pack  26  and timing by ESC  30 . ESC  30  will limit torque and open the ignition relay in unison for a programmable period of time when vehicle conditions indicate the correct code has not been entered.  
         [0022]     Referring to  FIG. 3 , a flow chart is used for describing operation of an embodiment of the invention at a high level. Programmable parameters of the invention are intended to implement the following features: 1) Overall feature ENABLEMENT and DISABLEMENT; 2) Numeric Anti-Theft Code that must be entered by the driver to keep the engine running after the park brake is released and which serves as a means of identifying the operator as someone allowed to operate the vehicle; 3) Programmable time delay that allows the engine to keep running after the park brake is released; 4) Parameter that defines how many digits shall be used as the anti-theft code, i.e. 3, 4, or 5 digit code, etc.; and, 5) Parameter to establish how long the vehicle is kept in the disable mode.  
         [0023]     Beginning at step  300  program operation begins with occurrence of a programmable event. Here the event that is required is that the vehicle engine be running (step  302 ). A negative result from that test places the program in a holding pattern along the NO branch from step  302 . Once the engine is running and the YES branch is followed by the program from step  302 , it is determined if the park brake has been set (step  304 ). If the park brake is found to have been set then the YES branch is followed to step  306  where it is determined if the clear switch  27 A has been pushed. If it has, then following the YES branch to step  308  clears the operator entered theft deterrent code. Execution then returns to step  302 .  
         [0024]     Returning to step  306 , the handling of entry of the theft deterrent code is considered. The NO branch from step  306  is followed when an operator fails to clear an entry. At step  310  the onboard computer determines if the code entered was correct. If YES, step  312  follows. If NO, then step  314  follows along the NO branch from the decision. Step  312  provides auditory and visual indication to the driver that the correct code has been entered and the program returns to step  302  for detection of release of the parking brake. Along the NO branch from decision step  310  step  314  is reached. Step  314  provides a different, generally more sustained and noticeable, set of visual and auditory indicators to the driver indicating an incorrect number has been entered. However, the vehicle is not disabled immediately and program execution returns to step  302  for detection of park brake release or possible entry of another anti-theft number.  
         [0025]     Exit from the anti-theft code entry portion of the loop occurs upon release of the park brake, detected at step  304 . Upon determination that the park brake is not set, the program follows the NO branch from step  304  to decision step  316 . The anti-theft code which was last entered is compared to the correct number at step  316 . If the correct code has been entered, normal operation of the vehicle is permitted. Following the YES branch from step  316  steps  326  and  328  are executed. Step  326  provides for stopping a warning timer (if operating). Next, step  328  verifies that the warning timer is off and returns the program to cycling through the loop by returning the program to step  302  (along the YES branch from step  328 ).  
         [0026]     Entry of the wrong anti-theft code results in some action being taken to fully disable the vehicle after a time delay. Following the NO branch from step  316  leads to step  318  and the start of a seven second warning timer. Following start of the time step  320  is executed to sound an audible alarm and to visually indicate to the driver that the engine will be stopped. The engine STOP light may be cycled to draw attention. Next, time out of the seven second timer is checked at step  322 . Upon expiration of the time out period, the YES branch is taken to step  324 , which results in the vehicle&#39;s ignition relay being opened and issuance of a torque speed limit signal to the engine controller. The dash engine stop indicator light is held on. Before expiration of the time delay program execution follows the NO branch from step  322  to step  328 , which operates as discussed above. The vehicle may be moved during the balance of the warning timer period. Following either step  324  or  328 , program execution returns to step  302  to monitor for changes in status, including entry of the correct anti-theft code. It may be seen that in order to clear an entry that the park brake must be set for detection at step  304 .  
         [0027]     While the foregoing flow chart describes an operation resulting in disablement of the engine, other triggers or limitations may be used. For example, instead of a park brake trigger a trigger such as vehicle speed exceeding 3 miles per hour might be used.  
         [0028]     The Anti-Theft System may be programmed to include the following: 1) Programmable Parameters which provide a means to modify the performance of the feature; 2) A programmable delay timer which allows the vehicle to be driven out of a dangerous situation without entering an anti-theft code; 3) An audible alarm which provides different warning cadences to indicate different modes of operation; and 4) The anti-theft code which can be programmed for different lengths of strings of characters.  
         [0029]     An example of an operational implementation of the invention follows. System operation is initiated upon one of the following. Vehicle is started with the Park Brake Set. Vehicle is started with the Park Brake NOT set and is driven &gt;3 MPH. Vehicle is stalled in an inconvenient location and needs moved.  
         [0030]     The Anti-Theft feature is armed under a variety of conditions. This means that the anti-theft code must be entered each time any of these events occur: 
    1. Ignition key is cycled from OFF to RUN or START.     2. Park Brake is set with the engine running and MPH &lt;3.     3. Driver has depressed the CLEAR switch on the switch pack with the Park Brake set and MPH &lt;3.     4. Driver has entered a bad access code with the park brake set or MPH &lt;3.    
 
         [0035]     The entry procedure for the enabling code requires: 
    1. The driver should start the engine with the park brake set.     2. The driver shall then enter the anti-theft code that has been pre-programmed into the ESC by depressing the respective numbered switches of the code from left to right. For example, if the code is 54321. The driver should press the switches in a 5 4 3 2 1 order. If the driver makes an error, the CLEAR switch should be depressed and released. Then the code should be entered again.     3. When the correct code has been entered, gauge cluster alarm will quickly beep 1 time and the ENGINE STOP light will blink once in unison with the single short beep. If the driver enters the wrong code, the gauge cluster will sound one long beep and the ENGINE STOP light will illuminate for 1.5 second.    
 
         [0039]     The engine is shut down as follows. The Anti-Theft code must be entered after the engine is running. However, the code must be entered within the time period specified by the Anti_Theft_Time_Delay programmable parameter (Default is 7 seconds) once the park brake is released or else once the vehicle is traveling more than 3 MPH, if the vehicle was started without the park brake being set first. 
    1. If the driver has failed to enter the anti-theft code and the vehicle is moving or the park has been released, the following alarms will occur for the time duration of the Anti_Theft_Time_Delay parameter.    
 
         [0041]     Gauge cluster beeper will emit repetitive beeps for Anti_Theft_Delay_Time (7 seconds).  
         [0042]     The Engine Stop indicator in the switch pack will flash slowly. 
    2. Once the delay period has elapsed, the ignition relay shall be opened for Anti-Theft-Active-Time (10 seconds) to ensure the engine has stopped. Once the engine is stopped, the relay will be released which will allow the restarting of the vehicle. The anti-theft code must be entered to allow normal operation of the vehicle once the vehicle is re-started.    
 
         [0044]     The shut down sequence will also be initiated under the following conditions while a bad or zeroed anti-theft code is entered: 
    1. Clear switch is pushed while vehicle is stationary and the park brake is released.     2. The park brake is already released when the engine is started.     3. The park brake is released with the engine running.     4. The vehicle is moving.    
 
         [0049]     The Theft Deterrent System is configured using a series of programmable parameters. Vehicles will be delivered from International with the feature turned off. The International Dealer will set each of these parameters using Diamond Logic Builder Program. The definition of each parameter/operating variable is as follows: 
    1. Theft Deterrent Code:    
 
         [0051]     The Theft Deterrent Code is the numerical code that the driver must enter each time the vehicle is to be moved. 
    2. Theft Deterrent Code Length:    
 
         [0053]     The Theft Deterrent Code length is a number that describes the number of digits in the Theft Deterrent Code. For example if the theft deterrent code is 7351, then the code length is 4. The user has the option to vary the code length using this parameter with a range of 1 to 8 digits. 
    3. Shut Down Delay Time:    
 
         [0055]     The shut down delay is the number of seconds that the engine will continue to run once the park brake is released. This allows the driver to move the vehicle from a critical location if the engine was stalled, without re-entering the code. The default is 7 seconds. This number can be changed from any number between 0 and 650 seconds. 
    4. Theft Deterrent Enable:    
 
         [0057]     The Theft Deterrent enable parameter allows the user to turn the feature OFF or ON. 
    5. Shut Down Active Time:    
 
         [0059]     The Shut Down Active Time is the number of seconds that the ignition relay is open and the torque limit control message is sent to the engine controller. The default is 10 seconds. The number can be changed from 10 to 60 seconds.  
         [0060]     The theft deterrent feature provides a means to protect the vehicle from unauthorized usage. The driver is required to enter a code each time the vehicle is started or the PARK BRAKE is set. The code may be entered at any time once the engine is running. If the theft deterrent code is not entered when the PARK BRAKE is released, the driver has a specific time to enter the proper code or else the engine will be stopped. Audible and visual indicators are provided to the driver to indicate the status of the code entering sequence and the engine shut down sequence. The Theft Deterrent feature is useable with both manual and automatic transmissions.  
         [0061]     The theft deterrent system of the present invention is well integrated with existing vehicle systems, making maintenance easier. The theft deterrent system provides two mechanisms for limiting vehicle operation, potentially defeating thieves. The present invention provides flexibility in implementation to meet customer specifications, low implementation cost, programmable operating variable settings, safe modes of operation, and all of the components used in the Anti-Theft System are tooled components of the patent holder, therefore, the complete Anti-theft System can be repaired or have programmable parameters modified by any of its dealerships, and switches used in this design match other switches in the vehicle and thus provides superior fit and finish.  
         [0062]     While the invention is shown in only a few of its forms, it is not thus limited but is susceptible to various changes and modifications without departing from the spirit and scope of the invention.