Abstract: An accelerator pedal position signal is transmitted by wire to the electronic control unit which operates a unipolar stepper motor to position the throttle in correspondence with the position of the accelerator pedal. A circuit of the electronic control unit monitors the response of the throttle to the release of the accelerator pedal and to the operation of the brake pedal in such a manner that unless the throttle is at, or at least within a predetermining distance of, its idle position within a certain limited time after the commencement of concurrence of accelerator pedal release and brake pedal application, the engine is shut down.

Abstract: High resolution microstepping of an unipolar stepping motor 18 is accomplished by applying from a look-up table the values of the SINE and COSINE of a given angle to the control circuit of a unipolar stepping motor. The difference between the present position and the desired position is calculated and depending upon the magnitude of the difference, the degree of microstepping is determined from four steps per ninety electrical degrees of motor rotation to thirty-two steps. By such selection, the positioning of the output shaft of the motor 18 is smoothly and accurately accomplished.

Abstract: High resolution microstepping of an unipolar stepping motor is accomplished by applying from a look-up table the values of the SINE and COSINE of a given angle to the control circuit of a unipolar stepping motor. The difference between the present position and the desired position is calculated and depending upon the magnitude of the difference, the degree of microstepping is determined from four steps per ninety electrical degrees of motor rotation to thirty-two steps. By such selection, the positioning of the output shaft of the motor is smoothly and accurately accomplished.

Abstract: In a digital control system wherein control voltages are analog voltages, a method and control system for generating a variable output bit resolution from an N bit analog to digital converter utilizing a control circuit to control the input spread of the voltage references to the A/D converter. Depending on the binary value of the MSD position, the input reference voltage spread is controlled. If the binary value is zero, the input reference voltage spread is one-half the normal value and the resolution is N+1 bits and if the binary value is zero for both the MSD and MSD-1 positions, the input reference voltage spread is one-fourth the normal value and the resolution is N+2 bits and so on until the first binary one value is found after consecutive preceding binary zero values.

Abstract: A low voltage supply control system provides on command a voltage doubling of the supply voltage to the fuel injector coils of a fuel injection system. The command signal is responsive to the magnitude of the battery voltage falling below a predetermined level at any time during the operation of the fuel injection systems be it on cold starting or during a component failure in the power generating system of the vehicle during operation. The advantage of this system is that the impedance of the fuel injector coils is typically many times higher than that of coils used without the low voltage supply control system. Overall the cost advantages of the low voltage supply control system are very attractive.

Abstract: A method of voltage compensation for an air/fuel ratio sensor as may be used in the exhaust system of a fuel injected internal combustion engine. The method comprises the steps of storing the design supply voltage in a look-up table, measuring the real time supply voltage and calculating a binary fraction value from the ratio of the present or real time supply voltage value and the design supply voltage value. The predetermined design threshold voltage value of the sensor is stored and then it is multiplied by the binary fraction value to get a real time threshold voltage value. The voltage output of the sensor is measured and compared with the real time threshold voltage value. In response to the comparison, a control signal is generated indicating whether or not the air/fuel mixture is lean.

Abstract: In microprocessor based control systems wherein several analog sensors are used to generate control signals of N bits, the system herein generates a digital signal having an N+1 bit resolution of the information. The N+1 bit resolution is generated from an N bit A/D converter by means of a network changing the reference voltage input to the A/D converter by an offset voltage which is a function of the least significant bit position. The network, in the absence of a control signal, generates a first range of reference voltages and in the presence of the control signal generates a second range wherein the limit voltages are changed by the offset voltage. The microprocessor reads and stores each N bit digital word from the same sensor and under the command of the control signal, sums the two digital words and the result is an N+1 bit digital word.

Abstract: A temperature compensation injector control system as used in an electronic fuel injection system for motor vehicles utilizes the value of the voltage levels across the coil (18) to determine the coil's (18) temperature. A multiplexer (20) responds to the value of the source of power (14) and the voltage drop across the coil (18) created by a small leakage current to generate digital signals to a microprocessor (10) for modifying injector control signals.

Abstract: The subject invention provides a baffle capable of floating on the electrolyte in a battery cell, and diverts with that floating baffle any splashing electrolyte away from a gas venting device at the top of the cell, particularly during vibration of that cell.

Abstract: An analog duty cycle to BCD converter for receiving pulsed digital signals (10) from an electronic computing unit (11) for operating an electromagnetic operated exhaust gas recirculation valve (12) having a plurality of valve actuators each responding to a binary valued voltage signal. The converter receives pulsed electrical signals (10) and through a low pass active filter means (14) and a comparator means (18), generates binary weighted control signals (22) for operating power transistors in a power switch means (24), a threshold means (20) provides a plurality of threshold voltage signals to the comparator means (18) to generate the control signals (22).

Abstract: A method of measuring barometric pressure with a manifold pressure sensor (62) in a microprocessor based engine control system utilizes known engine operating conditions to interrogate the sensor. Also on engine turn-off, a power latch signal (158) is generated to delay power removal until the throttle valve (160) is driven open and the pressure sensor (62) is interrogated for its value. This value at this time is the ambient or barometric value of pressure. This value is stored in the microprocessor's (26, 28) memory (84, 86) and maintained by means of a standby voltage (80). During engine operation, the pressure sensor (62) is interrogated and value of the stored barometric pressure is changed by one unit of pressure if the stored and measured values are unequal.

Abstract: An air flow sensor (10) as may be used to measure input air to an internal combustion engine has an aerodynamically designed impact tube (16) for diverting bypass air to a pair of sensors (28, 30). Downstream from the impact tube (16) is a venturi section providing exhaust means for the bypass air. The exhaust path configuration for the bypass air shields the sensors (28, 30) from a reverse pressure wave which can result from an engine backfire. The impact tube (16) operates to integrate the air velocity over a full radius of the air flow body (14).

Abstract: A dual microprocessor computing system is used to control an engine in a motor vehicle. Each system contains a Personality Programmable Read Only Memory (PPROM) containing system calibration data that is transferred from the PPROM to the read-write memories in the microprocessors. In order to identify each PPROM a byte of memory contains a check sum and a byte of the microprocessor memory contains an identical check sum. During data transfer, the check sums are compared. Also during data transfer, the amount of data being transferred within a predetermined interval is counted both at the transmitter and the receiver memories.

Abstract: A single crystal (100) dual microprocessor (26, 28) computing system utilizes a single frequency determining element (100) connected across the input pins of one of the microprocessors (26) and the output (102) of the element is connected to one input pin of the second microprocessor (28). The second pin of the second microprocessor (28) is connected to electrical ground (106). This configuration reduces the effective output impedance and results in higher oscillator amplitudes.

Abstract: A multiprocessing microprocessor based engine control system for an internal combustion engine controls the amount of fuel supplied to the engine. The various input-output devices used in engine operation, transmission control 20, spark advance control 22, etc., are controlled by dual microprocessors 26, 28 connected in parallel for partitioning and sharing of the various engine control functions.

Abstract: An extended range throttle body fuel injection system wherein overlapping or near-overlapping fuel quantity pulse width signals are compensated to maintain the operation of the injectors in a near linear operating mode. The system is capable of being implemented in software for controlling microprocessors in a microprocessor based system or in hardware logic for operation in a hardware system.

Abstract: A power processing circuit operatively and electrically connected to one regulated supply (16) voltage responds through a comparator means (24) and a monitor means (26) to generate a reset pulse (84) to a microprocessor (28) whenever the regulated supply voltage starts to go out of regulation. The comparator means functions both as a control circuit to maintain regulation as well as a comparator to determine when the base current of the pass transistor (52) begins to saturate the pass transistor. The monitor means (26) responding to this condition generates a minimum time length reset pulse to the microprocessor.

Abstract: A compensated dual injector driver circuit for controlling the current to either of a pair of electromagnetic solenoid fuel injectors is disclosed. The driver circuit includes a pair of analog bilateral switches operably connected to the control terminals of two driver transistors whose power terminals are coupled serially with the coils of the injector solenoids. A driver amplifier generating a current control signal for the driver transistors is connected to a common input of the two switches. Either of the switches is selected for closure by a logical input from a select line thereby choosing the individual injector to be energized. The driver amplifier in response to the leading edge of a control pulse regulates the conductance of the selected transistor with the current control signal to initially draw current through the injector coil until it reaches a peak value. At the time the peak current is attained, the driver amplifier then switches the control current to a holding value.

Abstract: The attachment device is made of two piece separable construction for use in securing flexible films and fabrics, hereafter referred to as material. One element has two longitudinal grooves facing in opposite directions, one groove being larger than the other groove. The other element has two longitudinal beads that positively interlock with the grooves of the first element when the two elements are pushed together by one of said beads and the larger groove acting as a pivot and the other bead and smaller groove being engageable by relative rotational movement of said elements about said pivot. Flexing of one or both elements allows for engagement of the shallower groove and complementary bead. The said interlocking action of the two elements is utilized to capture and secure material placed between the two elements. The shallower groove and complementary bead are disengageable by relative rotational movement of the two elements about said pivot when the two elements are pulled apart.