Vehicle Operation Inhibitor Control System

Abstract

A noise generator is energized from the ignition switch of a vehicle to generate a random frequency which is gated at fixed intervals to a plurality of binary counters and decoders which convert the frequency to a digital representation of a random number. The random number is displayed for a fixed interval of time after which the number is removed. In order to energize the starter circuit of the vehicle, the operator is required to operate keyboard pushbuttons corresponding to the digits previously displayed and in their proper sequence. The number entered by the operator is converted to a binary representation thereof and compared with that stored in the binary counters. The correct number must be entered within a fixed interval of time in order to provide a control signal which energizes the vehicle starter circuit.

Description

This invention relates to a vehicle operation inhibitor control system, and more particularly to such a system which inhibits vehicle operation until the operator has performed a test to determine whether his ability to safely operate the vehicle has been impaired.

An object of this invention is to provide a system which prevents starting of a motor vehicle until the operator has successfully performed a physiological test involving visual recognition, short term memory, and coordinated motor response.

Another object of this invention is to provide a vehicle operation inhibitor which requires the operator to accurately respond to a randomly generated display each time the vehicle is to be operated so that the test does not become a conditioned response.

In accordance with the present invention a random number is generated and displayed to the vehicle operator for a fixed interval of time subsequent to closure of the ignition switch. Generation of the number is accomplished by gating a random frequency signal to binary counters where the number is stored. The number stored is decoded and employed to drive a digital display unit, After the aforementioned interval of time, the display is disabled and a keyboard unit is enabled. In order to start the vehicle, the operator must be able to remember the number displayed and actuate the appropriate numbered key of the keyboard unit within a fixed interval of time. Each key number depressed by the operator is encoded in binary form and compared with the stored number to provide a starter circuit control signal indicative of whether the operator has depressed the correct keys. Means are also provided for preventing the starter circuit energization in the event the operator depresses more than one key at a time.

Other objects and features of this invention will be apparent from the following detailed description which should be read in conjunction with the drawings in which

FIG. 1 is a functional block diagram of the system;

FIG. 2 is a more detailed block diagram of the system;

FIG. 3 is a partial schematic and partial block diagram of the random-number-generating portion of the system;

FIG. 4 is a logic diagram of the encoder employed in the system;

FIG. 5 is a diagram of a portion of the disabled logic employed in the system;

FIG. 6 is a logic diagram of the key advance employed in the system;

FIG. 7 is a more detailed block diagram of the comparator employed in the system.

Referring now to the drawings and initially to FIG. 1, the inhibitor system is shown as connected between an ignition switch 10 and the starter circuit of the vehicle. The ignition switch 10 is connected to the positive terminal of a battery 12 the negative terminal of which is grounded. The system includes a random number generator 14 which controls a display unit 16. The random number is displayed for a time interval determined by a display time selector 18. After this time interval has elapsed, the displayed number is removed from the display 16 and a keyboard unit generally designated 20 is illuminated. The operator of the vehicle is required to depress the appropriate pushbuttons switches 1-0 within a time interval determined by a write time selector 22 in order to energize the starter circuit. To meet this requirement the selector 22 provides one input to an AND gate 24. A comparator 26 compares the number displayed with that generated by the operator from the keyboard unit 20, and if the number displayed and the number generated by the keyboard are identical, a second input to AND gate 24 is provided which actuates a set-reset flip-flop 27 to energize the starter circuit. If the number displayed is not accurately generated from the keyboard 20 or is accurately generated but not within the time fixed by selector 22, the flip-flop 26 is not set and the starter circuit cannot be energized.

Referring now to FIG. 2 the system is shown in greater detail. The random number generator 14 comprises a 0.1-second clock 28 which drives a decade counter 30. The decade counter 30 provides seven outputs at 0.1-second intervals to gate a random frequency signal from a noise generator 32 through a gate 34 to respective ones of seven 4-bit counters 36. The binary output of each of the counters 36 is fed to a decoder/driver unit 38 which decodes the binary signal and energizes a segmented display unit 40 to display the number. The final output of the decade counter 30 which occurs at 0.8 seconds sets a flip-flop 42 which provides an input to data flip-flop 43. The data flip-flop 43 has its clock input C connected with the output of the flip-flop 42, and its data input D connected with B+. The flip-flop 43 is initially reset to provide a "zero" at its Q output terminal and a "one" at its Q output terminal. The Q terminal of flip-flop 43 provides one input to an AND gate 44. The other input to the AND gate 44 is received from the clock 28. The output of the AND gate 44 is fed to a divider 46 which divides the output pulses by 5 to provide a 0.5-second clock input to the display time selector 18.

The display time selector 18 comprises a decade counter 48 which provides 10 outputs. Any one of which is selectable by a select switch 50 for the purpose of selecting a display time between 0.5 and 5 seconds. The select switch 50 is connected with the reset terminal R of flip-flop 42 to reset flip-flop 42 at the conclusion of the display time selected. The carry output of the decade counter 48 sets a flip-flop 52 which inhibits further operation of the decade counter 48. The 0.8-second output from decade counter 30 sets the flip-flop 42 which clocks the flip-flop 43 to produce a "one" at its Q terminal. This transition of the display gate signal from a "zero" to a "one" starts the 0.5-second clock input to the decade counter 48 and enables the decode/driver unit 38 thereby displaying the random number on the unit 40. Upon passage of the interval of time selected by the select switch 50 the flip-flop 43 is reset producing a "zero" at the Q terminal and a "one" at the Q terminal. This removes the 0.5-second clock input to the decade counter 48, disables the decode/driver unit 38, removing the random number from the display unit 40.

The Q terminal of flip-flop 43 is connected with an AND gate 54 which also receives an input from the carry output of decade counter 30. The AND gate 54 thus provides a 1-second clock input to the write time selector 22 which comprises a decade counter 56 providing ten separate outputs at 1-second intervals, a select switch 58 is adapted to select a write time of between 1 second and 10 seconds, and a flip-flop 59 which inhibits further operation of the decade counter 56 upon receipt of the carry signal from the decade counter 56. A data flip-flop 60 has its clock input terminal connected with the Q terminal of data flip-flop 43 and its data terminal D connected with B+. The flip-flop 60 is normally reset to provide a "zero" at its Q output terminal. At the conclusion of the display time as selected by the switch 50, the "one" at Q terminal of flip-flop 43 is fed to the C input of data flip-flop 60 to transfer the "one" on the D terminal to the Q terminal. This provides a "one" input to the AND gate 24 as well as energizing the keyboard light which illuminates the keyboard switches 1-0 and signals to the operator that the write time has now commenced and he should begin pressing the appropriate pushbutton switches.

The pushbutton switches 1-0 control a keyboard encoder 64 providing a binary output to seven 4-bit shift registers 66. The binary numbers from the encoder 64 are inserted into the individual shift registers under the control of a key advance 68 which responds to the pushing of each individual switch 1-0. The outputs of the shift registers 66 are compared with the outputs of the counters 36 in the comparator 26 and the results of that comparison are fed to the AND gate 24. The output of comparator 26 is a "one" if the operator has actuated the correct pushbutton in the proper sequence. Otherwise, the output of comparator 26 is a "zero." The AND gate 24 also receives an input from disable logic 70 which provides a "zero" input to the AND gate 24 in the event that the operator attempts to press more than one key at a time.

At the conclusion of the write time as determined by the position of the select switch 58 the data flip-flop 60 is reset to establish a "zero" on the Q output terminal deenergizing the keyboard light in the unit 20 and disabling the gate 24.

Referring now to FIG. 3 the noise generator 32 comprises a zener diode 72 which is connected to the B+ through a resistor 74. The zener diode 72 generates white noise which provides the random frequency required for the random number generation and which is amplified by a two-stage transistor amplifier 76 to a level compatible with the threshold level of the gate 34. The gate 34 is shown to comprise a plurality of AND gates 34a-34g which receive one input from the generator 32 and a second input from set-reset flip-flops 34a'-34g'. The set-reset flip-flops 34a'-34g' are reset from individual output terminals of the decade counter 30 at time 0.2 seconds through 0.8 seconds respectively. During the 0.7-second interval the AND gates 34a-34g are sequentially enabled and, therefore, gate a random number of pulses, to the respective 4-bit counters 36a-36g, determined by the frequency variations in the output of generator 32 during the time the respective gates 34a-34g are enabled. The output of the bit counters 36a-36g are fed to respective decode/drivers 38a-38g. The decode/drivers 38 are enabled and disabled by the "one" and "zero" output respectively from the Q terminal of data flip-flop 43.

Referring now to FIG. 4 the keyboard encoder 64 comprises OR gates 78, 80, 82, and 84 which provide a binary representation of the particular pushbutton switch actuated. By way of example, the generation of the binary number representing closure of pushbutton 5 is accomplished in the following manner. Pushbutton switch 5 is connected only to OR gates 78 and 82 and thus upon closure of pushbutton switch 5 a "one" output is obtained from OR gates 78 and 82 and a "zero" output is obtained from OR gates 80 and 84 generating the binary number 5 (0101).

Referring now to FIG. 5 the disable logic 70 is shown to comprise a plurality of set-reset flip-flops 86a, 86b, 86c, etc., connected with respective ones of the pushbutton switches 1-0. The outputs of the flip-flops 86b and 86c are connected as inputs to AND gates 88a, 88b respectively. The output of 86a is connected to both AND gates 88a and 88b. The outputs of gates 86a and 86b are connected to an OR gate 90. The output of the OR gate 90 is connected to a set-reset flip-flop 92, the output of which is inverted by an inverter 94 and applied to AND gate 24. Should the operator depress both pushbutton switches 1 and 2 a "one" output occurs at AND gate 88a which is passed through the OR gate 90 to set flip-flop 92 and provide a "one" input to the inverter 94 which provides a "zero" output. The "zero" output from inverter 94 will prevent setting of the flip-flop 27 thereby preventing operation of the vehicle starter circuit. The same sequence of events will occur should the operator actuate pushbuttons 1 and 3 simultaneously, since a "one" output would be obtained from AND gate 88b. The remaining portion of the disable logic operable in response to simultaneous actuation of others of the pushbuttons will be apparent to those skilled in the art, and in the interest of brevity is omitted.

Referring now to FIG. 6 the key advance 68 is shown to comprise in OR gate 96 which receives an input from each of the pushbutton switches 1-0. The output of OR gate 96 clocks a decade counter 98 which enables the appropriate shift registers 66 to receive the coded number corresponding to the key depressed.

Referring now to FIG. 7, the comparator 26 is shown to comprise nine individual comparators 26a-26i. The binary numbers from four of the shift registers 66 are compared with the binary numbers from four of the counters 36, in the comparators 26a-26d. If the binary numbers are the same, outputs from each of the shift registers 26a-26d are fed to the comparator 26e which provides an output to the comparator 26i. The binary numbers from the three remaining shift registers 66 are compared with the binary numbers from the three remaining counters 36 in the comparators 26f-26h. If the binary numbers are the same, outputs from the comparators 26f-26h are fed to the comparator 26i which produces a logic "one" output, if all seven binary numbers are the same, and a "zero" output, if any of the numbers are not the same. The output of comparator 26i is fed to the AND gate 24.

Claims

Having thus described my invention, what I claim is:

1. In a motor vehicle provided with a source of voltage, an ignition switch and a starter circuit, inhibitor means connected between sad ignition switch and said starter circuit for controlling the energization of said starter circuit and comprising; random noise-generating means, clock means for generating a timing signal, counter means, gate means responsive to the output of said clock means for gating the output of said noise-generating means to said counter means at fixed intervals of time to store in binary form a first plurality of random numbers in said counter means, display means, means connected to said counter means for energizing said display means to display code symbols related to said first plurality of random numbers, means for deenergizing said display means a predetermined interval of time after said first plurality of random numbers are displayed, manually actuable switch means including a plurality of selectively actuable switches corresponding to said code symbols, encoder means for providing a binary output in response to actuation of said switches, shift register means responsive to the output of said encoder means for storing a second plurality of binary numbers, means for comparing said first binary numbers in said counter means with said second binary numbers in said shift register means and for developing a first logic output indicative of the comparison, means responsive to deenergization of said display means for providing a second logic output a predetermined interval of time after deenergization of said display means, means for performing a logical AND function and responsive to said first and second logic outputs for providing a control signal to said starter circuit.

2. The system defined in claim 1 further comprising means responsive to simultaneous actuation of two or more of said switches for disabling said logical AND function performing means.

3. In combination a clock mechanism, means cooperating with said clock mechanism to produce during a sequence of clock intervals a succession of random symbols in code, means for respectively storing each of the coded symbols in the sequence produced, means for respectively decoding each of the coded symbols and for respectively displaying each of the symbols in visible form and in the sequence in which the coded symbols were produced, operator-actuable means bearing indicia corresponding to respective ones of each of the symbols displayed and actuable to produce coded symbols of sequence selected by the operator, means effective to compare respective ones of the coded symbols produced by said operator-actuable means and in the sequence produced thereby with respective ones of the stored coded symbols and in the sequence stored, and elements operable when the compared coded signals coincide.

4. Apparatus for preventing operation of a motor vehicle by an incapacitated person comprising means for displaying a succession of random ones of predetermined symbols in spaced positions for a fixed interval of time, operator-actuable selector means including individual actuable members provided with indicia corresponding to the predetermined symbols, means providing a control signal when the operator actuates the individual members in sequential order corresponding to the sequence of the symbols displayed and within a predetermined interval of time, and means responsive to said control signal for preventing operation of said vehicle.

5. In a motor vehicle provided with a starter circuit apparatus for controlling starting of the motor vehicle comprising bistable means coupled to the starter circuit and normally preventing energization of said starter circuit but actuable to permit energization of the starter circuit, display means capable of displaying one of a plurality of symbols in any one of a plurality of positions, display control means including first time-delay means coupled to said display means for generating a control signal effective to cause a succession of random symbols to be displayed for a first interval of time and removed after said first interval of time, a plurality of manually actuable switch means energizable after said first interval of time, each switch means provided with a symbol corresponding to respective ones of said plurality of symbols, means coupled to said display control means and said manually actuable switch means for actuating said bistable means in response to actuation of said switch means in a sequence corresponding to the symbols displayed, second time-delay means energizable at the conclusion of said first interval of time for preventing actuation of said bistable means after a second interval of time.

6. Apparatus for preventing operation of a motor vehicle by an incapacitated person comprising control means coupled to operating apparatus on said vehicle, said control means having an enabled condition permitting operation of said vehicle and a disabled condition preventing operation of said vehicle, a display unit mounted on said vehicle in a position to be viewed by an operator thereof, means connected with said display unit for providing unanticipated different sequences of graphical information in the form of a position sequence of symbols to be displayed on said display unit for a predetermined length of time, manually operable means having indicia which correspond to the symbols respectively so that a person with capacity can manually actuate the same in timed succession in response to the symbols displayed and their position sequence, comparator means coupled to said manually operable means of said display unit and said control means for causing said control means to assume its enabled condition when an operator of said vehicle manipulates said manually operable means at successive times in exact correspondence with the position sequence of the symbols previously displayed on said display unit within a predetermined length of time after said information is removed from said display unit, said control means remaining in its disabled condition in the event the operator of said vehicle fails to manipulate said manually operable means at successive times in exact correspondence with the position sequence of the symbols previously displayed on said display unit so as to prevent operation of said vehicle by an incapacitated person.