Abstract:
A security system for a vehicle includes a keyboard including a start key and a washout key and adapted to receive a user code. A processor is operably coupled to the keyboard for receiving signals indicative of entry of the user code actuation of the washout key and, wherein the processor provides an output signal if the user code is entered and is followed by actuation of the start key. The processor also provides the output signal if the start key has been entered during an adjustable time period after the vehicle has been turned off. However, if the washout key is actuated, the processor does not provide the output signal upon actuation of the start key during the time period after the vehicle is turned off. A controlled device is operably connected to the processor and controls a component of the vehicle to allow the vehicle to start when the output signal from the processor is received.

Description:
This is a continuation of U.S. patent application Ser. No. 08/796,882, filed on Feb. 7, 1997, now U.S. Pat. No. 5,821,631. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates in general to vehicle anti-theft security systems. More particularly, the present invention relates to a keyless ignition system where an operator must provide a preselected code to start and operate the vehicle. 
     Self-powered vehicles used in the construction and agricultural vehicles are subject to theft and operation by unauthorized persons. Unlike most highway vehicles, which typically are only operated by one or a few individuals over a lengthy period of time, selfpowered construction equipment and certain types of agricultural equipment are often operated by many persons, especially when the equipment is moved between work sites. Workers in the construction and agricultural fields are often employed on a short-term basis and tend to change employers frequently, which compounds the difficulty of maintaining vehicle security. 
     Keyless systems for allowing operation of a vehicle without using a conventional key have long been known. These keyless systems typically require the entry of a proper sequence of key depressions through an array of switches, after which the engine starting controls operate normally. These systems obviate the need for an authorized user of the vehicle to carry keys to gain access. Some systems developed for the automotive industry have used a combination of a conventional key along with a keyboard to accept and recognize a preselected code. After entry of the preselected code, the key can be turned in a conventional manner to start the engine. In the event of the car stalling, a timer is initiated that allows the car to be started without re-entry of the preselected code. Thus, if the vehicle does stall in traffic, it can be turned on simply by turning the ignition key as is conventional. After a preselected period has lapsed, the system will enter a secured mode where the correct preselected code must be entered to start the vehicle. 
     Many systems further allow the system to be deactivated, for example, while the vehicle is being serviced or driven for other reasons. Although handy, placement of the system in an unsecured mode makes the vehicle particularly vulnerable. If the operator forgets to reactivate the security mode, the vehicle is easily susceptible to theft. 
     SUMMARY OF THE INVENTION 
     In a first embodiment, a security system for a vehicle includes a keyboard for receiving input codes that comprise an access code and a start code. As used herein an access code is either a “user code” or a “master code”. A user code is known to an operator of the vehicle and allows the vehicle to be started. A master code is known to the owner of the vehicle and allows the owner to change parameters of the system that can not be changed by only entering the user code. 
     In the first embodiment, a processor is operably coupled to the keyboard for receiving signals indicative of each access code and the start code, wherein the processor provides an output signal if an input code corresponds to the access code and is followed by the start code. The processor also provides the output signal if the start code has been entered during an adjustable time period after the vehicle has been turned off. A controlled device is operably connected to the processor and controls a component of the vehicle to allow the vehicle to start when the output signal from the processor is received. 
     In a second embodiment, a keyless security system for a vehicle includes a keyboard for receiving input codes that comprise access codes and a start code, and a controlled device for controlling a component of the vehicle to allow the vehicle to start. A processor is operably coupled to the keyboard for receiving signals indicative of each access code and the start code and is operably coupled to the controlled device for providing an output signal for controlling the controlled device. The processor provides an output signal only if an input code corresponds to an access code and is followed by the start code, or if the start code has been entered during an adjustable time period after the vehicle has been turned off. The time period is adjusted through entry of the master code. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram of a first embodiment of the present invention; 
     FIG. 2 is a front view of a keypad used with the first embodiment of the present invention; 
     FIG. 3 is a first flow chart of the sequence of operations followed by an apparatus of the first embodiment of the present invention; 
     FIG. 4 is a front view of a keypad used with a second embodiment of the present invention; and 
     FIG. 5 is a second flow chart of the sequence of operations followed by an apparatus of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1 and 2 illustrate an embodiment of a security system of the present invention generally at  10 . The security system  10  includes a microprocessor  12  that receives signals from a keyboard/display panel  14  and suitable memory  16 . Using a program  15  stored in the memory  16 , the microprocessor  12  receives input codes from the keyboard  14 . If the input codes correspond to an access code, the microprocessor  12  provides suitable control signals to a controlled device indicated at  18  that allows a vehicle, not shown, that the security system  10  is attached to, to be started. The security system  10  obviates the need for a conventional key switch, and in effect, replaces the key switch thereby providing a keyless ignition system. 
     As used herein an access code is either a “user code” or a “master code”. A user code is known to an operator of the vehicle and allows the vehicle to be started. A master code is known to the owner of the vehicle and allows the owner to change parameters of the system that can not be changed by only entering the user code. 
     The controlled device  18  can be any device that has two selectable operating states, one of which will prevent the vehicle from starting. For example, the controlled device  18  can be a starter relay, a fuel cut-off switch, an ignition module, or any other suitable device necessary to operate the vehicle. The control signals provided by the microprocessor  12  are normally low-power signals used to control higher power devices. The security system  10  is particularly well suited for use with construction vehicles such as skid steer loaders. 
     It will be appreciated that the circuitry illustrated in FIG. 1 could be formed as a single integrated circuit. It will also be appreciated that, instead of using the microprocessor  12  illustrated, an array of logic devices designed for the flow chart of FIG. 3 could also be used. However, the microprocessor  12  is particularly attractive where a microprocessor has already been incorporated in the design of the vehicle, to control other functions, such as those relating to engine operation. The amount of computing time required to perform the security system  10  is small in comparison with the computing power of a microprocessor so that a single microprocessor could control all of the electrically controlled functions of the security system  10 , in addition to operating other accessories  17  and carrying out other tasks of the vehicle. 
     FIG. 2 illustrates a close-up view of a first suitable keyboard and integrated display unit  14 . In the embodiment illustrated, the keyboard  14  includes ten individual keys  20 ,  21 ,  22 ,  23 ,  24 ,  25 ,  26 ,  27 ,  28  and  29 . The keys  20 - 29  can take many forms, for example, the keys  20 - 29  can be mechanical switches or can be touch-sensitive or pressure-sensitive contact areas of a larger single panel. In the embodiment illustrated, the key  20  is used to “wake-up” the security system  10  and indicate to the microprocessor  12  that input codes will be entered. The keys  21 - 28  are numbered  1 - 8 , respectively, and are used sequentially to form possible access codes. The keys  22 ,  25  and  28  are also used to enter commands to the microprocessor  12  for various functions. Activation of keys  25  and  28  are described below. The key  22  is used to relieve pressure in hydraulic lines for powering remote equipment that can be connected to the vehicle. The key  29  is an “enter key” and is used to signify the end of an input request. A display device  30  such as an LCD or LED decimal display  30  is provided to indicate the operating state of the microprocessor  12 , request inputs and/or reflect keys depressed during operation of the keys  21 - 28 . 
     The logic of the computer program  15  being implemented by the microprocessor  12  is illustrated in a flow diagram of FIG.  3 . The system  10  has five operating states or modes that include a “secured sleep mode,” a “input code mode,” a “vehicle run mode,” a “non-secured, timed, start-ready mode,” and a “parameter adjustment mode.” Initially, the system  10  including the keyboard  14  is in the “secured sleep mode” as indicated by a block  100 . In this mode, the vehicle is turned off and secured in that it can not be started without first providing a valid code sequence. During this mode, the microprocessor  12  is waiting for actuation of the key  20  indicating that the microprocessor  12  should enter the “input code mode.” In the “input code mode,” the microprocessor  12  waits for sequential operation of any of the keys  21 - 28 . As will be described in detail below, actuation of the key  25  at a decision block  102  allows for immediate operation of the vehicle without entering in the user code or the master code. Operation of the vehicle is only available if a selected time period T 2  has not elapsed. In the embodiment illustrated, a delay timer  32  is used to measure the selected time period, and provides a signal to the microprocessor  12  where the selected time period T 2  has expired. 
     Assuming for the moment that actuation of the key  25  has not occurred, program flow continues to an input block  104 . At input block  104 , the microprocessor  12  receives from the keyboard  14  a sequence of key actuations representative of an input code. Completion of one input code is represented by actuation of the key  29 . After actuation of the key  29 , the input code is compared with the user code and the master code indicated at a decision block  106  and stored in memory  16  at  38  and  40  respectively. If the input code received at input block  104  is not valid, program flow returns to input block  100  and re-enters the “secured sleep mode” and, if desired, the microprocessor activates an alarm  36 . 
     If the input code matches the user code or the master code, program flow continues to a decision block  108 . At decision block  108 , the microprocessor  12  ascertains whether the user code or the master code has been entered. In the embodiment illustrated, the microprocessor  12  compares the input code with the user code  38 . If the input code matches the user code  38 , program flow continues to a decision block  110 . At decision block  110 , the microprocessor  12  awaits actuation of the key  25  signifying that the user is prepared to operate the vehicle. Upon actuation of the key  25 , the microprocessor  12  provides suitable control signals to the controlled device  18  at a block  112  that enables the vehicle to be started and operated normally. The timer  32  can be used at block  110  to ensure that the key  25  is actuated within a prescribed time period T 1  stored in memory  16  at  42 . If the key  25  is not actuated within the time period T 1 , program flow returns back to the “secured sleep mode” at block  100 . 
     The “vehicle run mode” is illustrated in FIG. 3 at a block  114 . With the vehicle operating, program flow cycles between blocks  116 ,  119 ,  121  and  118 . The microprocessor  12  monitors for actuated of the key  22  or the key  28 . Activation of the key  22  (“AUX RELIEF”) reduces pressure in an auxiliary hydraulic system to allow an attachment to be uncoupled from the vehicle. If the key  22  has been actuated, the system  10  reduces the pressure in the auxiliary hydraulic system at block  121 . When the operator actuates the key  28 , program flow continues to block  120  where the microprocessor  12  provides suitable control signals to the controlled device  18  or ceases transmission of the control signals provided to place the system  10  in an operating state in order to prevent the vehicle from being operated. 
     Program flow then continues to decision block  122  whereat the microprocessor  12  ascertains if non-secured starting of the vehicle is available. In the embodiment illustrated, the availability of non-secured starting of the vehicle is stored as a Boolean variable “status” in memory  16  at  46 . The Boolean variable “status” has two possible values “delay” indicating that non-secured starting is available for a selected time period T 2  stored in memory  16  at  48 , and “no delay” indicating that non-secured starting is not available. Assuming that non-secured starting is not available, program flow returns back to block  100  and the microprocessor returns to the “sleep secured mode.” If, on the other hand, non-secured starting is available, the microprocessor  12  initiates the delay timer  32  at block  124  and then returns to the “sleep secured mode” at block  100 . 
     Non-secured starting of the vehicle is available at block  102  with actuation of the key  25 . Upon actuation of the key  25 , program flow continues to decision block  126  whereat the microprocessor  12  ascertains if non-secured starting is available by checking the value of the “status” variable. If non-secured starting is available, program flow continues to decision block  128  where the microprocessor  12  ascertains if the delay timer  32  has timed-out. If the delay timer  32  has timed-out (exceeded the time period T 2 ), program flow returns back to the “sleep secured mode” at block  100 . If, on the other hand, the delay timer  32  has not timed-out, program flow continues to block  112  where the microprocessor  12  provides suitable control signals to the controlled device  18  to allow the vehicle to be operated. 
     It should be understood that at any time during the starting sequence identified by program flow through blocks  100 ,  102 ,  106 ,  108 ,  110  and  112 , or through the “non-secured” starting path identified by blocks  100 ,  102 ,  126 ,  128  and  112 , the microprocessor  12  can ensure that the vehicle is properly configured for operation. 
     Operating parameters such as the user code  38 , the master code  40 , the value of the “status” variable, and the length of the time period T 2  for non-secured starting can be changed or adjusted with entry of the master code  40  as represented by program flow from decision block  108  to block  130 . This operating mode can be entered with or without the vehicle engine operating. At block  130 , the microprocessor  12  provides an acknowledgement, via the display  14 , to indicate to the operator that the master code has been entered. Program flow then continues to block  132 . As represented by block  132 , only five different key actuations are recognized by the microprocessor  12 . They are key  21 , key  22 , key  23 , key  24 , and key  29 . Actuation of the key  21  by the operator changes the value of the “status” variable between “Delay” and “No Delay” at block  134 . The microprocessor  12  records in memory  16  at  46  the selected mode chosen by the operator and returns program flow to block  132 . 
     If the key  22  is depressed, program flow continues to block  136  where the operator is prompted for a new user code. Upon actuation of the “enter” key, after a desired sequence of keys  21 - 28  have been depressed, the microprocessor  12  replaces the old user code with the new user code stored at  38  in memory  16  and returns program flow to the block  132 . 
     If the key  23  is depressed, program flow continues to block  138  where the operator is prompted for a new master code. Upon actuation of the “enter” key, after a sequence of keys  21 - 28  have been depressed, the microprocessor  12  replaces the old master code with the new master code stored at  40  in memory  16  and returns program flow to the block  132 . In a preferred embodiment, the master code is not changeable by the owner and is recorded by the manufacturer, being crossreferenced to the vehicle&#39;s serial number. In the event the owner forgets the master code, the manufacturer can then provide it. 
     If the key  24  is actuated, program flow continues to block  140  where the operator is then allowed to change the duration of the time period T 2  for non-secured starting. The operator can either enter a desired duration by using the keys  21 - 28 , which can, in one embodiment, represent hours with a maximum duration of eight hours. Otherwise, repeated actuation of the key  24  can sequentially display a plurality of preselected time periods. Pressing the key  29  stores the selected value for time period T 2  in memory  16  at  48  and returns program flow to block  132 . 
     If the key  29  is depressed at block  132 , the program exits the “Parameter Adjustment Mode” and returns to the “secured sleep mode” at the block  100 . 
     FIG. 4 illustrates a second suitable keyboard and integrated display unit  14 A. In the embodiment illustrated in FIG. 4, the keyboard  14 A includes keys  181 ,  182 ,  183 ,  184 ,  185 ,  186 ,  187 ,  188 ,  189  and  190 . The keys  181 - 190  are numbered and are used sequentially to form input codes. A key  191  is provided to initiate starting by providing a start code if a valid user or master code has been entered. The engine of the vehicle is turned off when a key  192  is depressed. An “AUX RELIEF” key  193  is provided to release pressure in an auxiliary hydraulic system, as described above. Indications of improper operation of the keyboard  14 A are provided to the operator through a LED  194  identified as “ERROR.” Proper operation of the keyboard  14 A is indicated through an LED  195  labeled “RUN.” 
     FIG. 5 illustrates a second flow diagram of the computer program  15  implementable by the microprocessor  12 . Operation of the system  10  pursuant to the flow diagram of FIG. 5 is as follows. In the embodiment illustrated, the system  10  has five operating states or modes that include a “secured sleep mode,” a “command input mode,” a “vehicle run mode,” a “timed start-ready mode” and “parameter adjustment modes.” Initially, the system  10  including the keyboard  14 A is in the “secured sleep mode” as indicated by block  200 . In this mode, the vehicle is turned off and secured in that it cannot be started without first providing a valid user or master code. During this mode, the microprocessor  12  is waiting for actuation of any of the keys  181 - 190 . Upon activation of any key  181 - 190 , the microprocessor  12  enters the “command input mode.” In the “command input mode,” the microprocessor  12  checks the key depressed with allowable commands, and if necessary, waits for additional keys, which taken in sequence with the first key, represent an input Code. At block  202 , the microprocessor  12  compares the input code with a number of possible valid codes, each of which will be discussed below. 
     If the input code equals the user code, as indicated at block  204 , the microprocessor awaits further input from the operator, as indicated at block  205 . If the operator then activates the key  191 , program flow continues to block  206  whereat the microprocessor  12  provides suitable control signals to the control device  18  that enables the vehicle to be started and operated normally. 
     The “vehicle run mode” is illustrated in FIG. 5 at a block  210 . With the vehicle operating, the system  10  awaits further inputs to the keyboard  14 A at block  212 . If activation of the “AUX RELIEF” key  193  is detected at block  213 , program flow continues to block  214  where the microprocessor  12  provides a control signal to suitable valves to reduce pressure in the auxiliary hydraulic system. If activation of the stop key  192  is detected at block  215 , indicating that the vehicle operator desires to turn off the vehicle, program flow continues to block  216  where the microprocessor  12  provides suitable control signals to the controlled device  18  or ceases transmission of the control signals provided to the controlled device  18  in order to place the vehicle in an operating state that prevents the vehicle from being operated. Program flow then continues back to input block  200 . 
     Referring back to input block  205 , if the operator has entered a preselected code as determined at block  205 , the delay time T 2  can be adjusted at block  224 . For example, activation of one of the keys  181 - 190  following the preselected code indicates to the system  10  that the delay time T 2  should equal the numerical value in hours of the key depressed. 
     The delay timer  32  can be activated following entry of the delay time at block  224  represented by the dashed block  226 . In this embodiment, the delay timer  32  would run continuously whether the vehicle is running or not. Once the delay timer  32  has timed out (exceeded T 2 ), the operator then must reenter a new delay time in order to reset the delay timer  32 . 
     The delay timer  32  can also be activated at block  228  after the vehicle has been turned off. In this alternate embodiment, the delay timer  32  runs each time the vehicle is turned off. 
     As with the embodiment illustrated in FIG. 3, use of the delay timer  32  allows the operator to quickly restart the vehicle without entry of either the user code or the master code. In the embodiment illustrated, a “Delay Key” represented at block  230 , must be depressed prior to activation of the start key  191 . Use of the delay key inhibits starting the vehicle inadvertently by activation of the start key  191  as well as provides a minimal level of security to prevent unauthorized operation of the vehicle. As illustrated in FIG. 5, if the Received Code at block  202  equals the delay key, which can be any one of the keys  181 - 190 , or a short sequence thereof, the system  10  ascertains whether the delay timer  32  has timed out at decision block  232 . If the delay timer  32  has timed out, program flow returns to block  200 . If the delay timer  32  has not timed out, program flow continues to block  231  and the system  10  awaits activation of the start key  191 . 
     Returning back to block  202 , if the operator has entered the master code at block  202 , program flow continues through block  240 , representing entry of the master code, to block  242  whereat the operator can select different parameters to adjust. For example, the operator can change the user code as represented at block  244 , or change the delay key as represented at block  246 . The operator can also enter a delay timer at block  248  and start the delay timer at block  250 , options of which were available with entry of the user code. When the operator has adjusted all desired parameters, program flow returns to block  242 . With activation of the start key  191 , the program flow continues to block  206 . In t his embodiment, the master code is unchangeable for the reasons discussed above. 
     In the embodiment illustrated, a “washout key” is provided to disable the delay timer  32 . The washout key can be a separate key or any one of the keys  181 - 190 . As represented at block  252 , the washout key is activated either when the vehicle is turned off, as illustrated, or while the vehicle is running. The washout key is particularly advantageous for rental shop owners that rent the vehicle for a period of time to customers. In this manner, after the vehicle has been returned to the rental shop, the owner can activate the washout key to prevent delayed starting by setting the delay time T 2  to zero at block  254 . Those skilled in the art will appreciate that other status variables can be used and set to prevent delayed starting, as shown on block  256 . Alternatively, activation of the washout key can also render the user code invalid, as shown on block  258 . 
     Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.