The Bendix Corporation

Allied Corporation

Other

Siemens-bendix Automotive Electronics Limited

Ralph W Carp

Danny O Wright

Robert E Weber

Leoncio T Ang

Roman O Marchak

Harold E Weissler, Ii

Guy T Rini

William R Groff

Paul R Kudlaty

Michael Slavin

George T Bata

William A Peterson, Jr

Bertice E Walker, Jr

Mark C Harvey

Richard J Hyder

Grant Arthur Cornell

John F Slack

Thomas F Gosnell, Sr

Lawrence D Leadbetter

Laurence D Leadbetter

A current controlled electronic circuit for a hot wire air flow meter having a symmetrical bridge circuit to measure the mass of the airflow. The present current bridge arrangement requires very few adjustments to select a few resistors for obtaining a required temperature differential and compensation for variations in the temperature coefficient of resistance of both the heated and cold resistors. This is accomplished by placing of a voltage divider in parallel with the sensing leg and a first amplifier responding to the voltage divider and the sensing let to control the current in the compensation leg. A second amplifier responds to the compensation leg for controlling the power to the sensing leg.

Current controlled electronic circuit for a hot wire air flow meter

A symmetrical bridge circuit having a sensing leg means and a compensation leg means for measuring mass air flow in the input of an internal combustion engine utilizes the same type of sensing and compensation elements with the same temperature coefficients. The sensing leg means and the compensation leg means are coupound circuits each having a conventional bridge leg and a voltage divider leg. The conventional bridge leg outputs are connected through voltage follower circuits controlling the input of the voltage divider legs. The conventional leg of the sensing leg means contains the sensing element and the voltage output therefrom is a function of a first factor. The voltage divider leg connected to the output of the voltage follower circuit further divides the voltage output by a second factor. The compensation element is connected in the voltage divider leg of the compensation leg means. The voltage output of the conventional leg of the compensation leg means is a function of a second factor and the voltage output from the voltage divider is a function of the first factor. The outputs of the voltage dividers control a power driver means supplying power to the bridge circuit. The output stage of the bridge circuit compares the voltage supplied by the power driver means with a fixed reference voltage to generate an analog signal representing the mass of the air flowing across the sensing element. The symmetrical bridge circuit does not require compensating capacitors and special amplification circuits for the compensation legs.

Symmetrical bridge circuit for measuring mass air flow

A control system for reversing the rotation of a field wound motor is used in electric power steering systems. The system responds to control signals from a control means 25 to energize opposite legs of a bridge circuit 14 to direct current through the field winding 10 in the correct direction. At the same time the armature winding is energized. The control system provides a failure detection means 18 for the checking of the various control signals and the operation of the system to determine if there is any system failure to provide for a failsafe operation.

Control system for reversing the rotation of a field wound motor

An automatic calibration selection for an automotive control system allows the use of one basic electronic control unit (20) for a family of motor vehicles. In each motor vehicle, a unique valued resistor (10) is located in or adjacent to the wireharness and near the electronic control unit connector (12). This resistor (10) provides an input to a voltage divider network to select a voltage value representing the particular control parameters for the vehicle. The voltage operates to address (24) a read only memory (22) to place the proper calibration constants in the electronic control unit (20).

Automatic calibration apparatus for an automotive control system

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).

Analog duty cycle to BCD converter

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.

Power processing reset system for a microprocessor responding to sudden

A hybrid electronic control unit for regulating the air/fuel ratio of an internal combustion engine is disclosed. The electronic control unit is divided into two functionally distinct parts including an analog function generator and a digital function generator. The analog function generator receives analog signals to process efficiently by analog scaling, amplification, multiplication, and division while the digital function generator receives digital and logic inputs to process efficiently by addition, subtraction, and comparison. The analog function generator interfaces with the digital function generator by an analog signal from a D/A converter and other unconverted digital output signals from the digital function generator. Preferably, the analog function generator provides an open loop air/fuel ratio calibration based upon a speed density calculation including special condition corrections to the base calibration. Primarily, the digital function generator is a microprocessor implemented closed loop integral controller providing a closed loop correction signal to the open loop scheduler. The closed loop correction signal is provided from the digital function generator by a pair of cascaded digital integrators having different authority levels and integration rates. The cascade is formed by combining an asymmetric primary integrator waveform which has one RPM dependent ramp rate with a symmetric secondary integrator waveform which has a time dependent ramp rate. The primary integrator has a smaller authority and a faster ramp rate than the secondary integrator.

Hybrid electronic control unit

An electronic control unit for regulating the air/fuel ratio of an internal combustion engine is disclosed. The electronic control unit has an open loop calibration for regulating air/fuel ratio that is corrected with a closed loop correction signal developed by an integral controller. The open loop calibration is a speed-density based schedule which is combined with corrections for special conditions to account for the operating parameters of the engine at any instant. Included in these special condition corrections are provision for start and warm-up features. The start feature includes an enrichment pulse generator whose pulses have a duration dependent upon the engine operating temperature and speed which are inhibited while the engine is above a predetermined RPM. The warm-up feature includes a time and temperature dependent enrichment which is linearly multiplied by an engine load factor. The warm-up feature further includes a time dependent holding level or delay from which the enrichment factor value decays during warm up and a feature to defeat this holding level above a certain engine operating temperature.

Start and warm up features for electronic fuel management systems

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. The peak and the holding current levels are measured by a negative feedback loop from a sense resistor commonly connected in series with each set of coils and driver transistors to indicate the magnitude of current therethrough. The circuit further includes a means for controllably collapsing the magnetic field stored in the injector coils when the injector driver transistors are turned off in response to the trailing edge of the control pulse. Compensation is provided to the driver amplifier for altering the hold level current in accordance with variations in the battery voltage. The differing levels of hold current with changing battery voltage will modify the closing time of the injector oppositely to those changes produced in the opening times by the battery voltage.

Compensated dual injector driver

An electronic control unit for regulating the air/fuel ratio of an internal combustion engine is disclosed. The electronic control unit has an open loop calibration for regulating air/fuel ratio that is corrected with a closed loop signal developed by an integral controller. The integral controller bases the closed loop correction signal on a signal from an exhaust gas composition sensor located in the engine exhaust manifold. Various conditions of the system are sensed by a closed loop sensor condition detector to provide information on whether the sensor is up to operating temperature and is operative. If the exhaust gas sensor is functioning and the operating system parameters indicate the system operation should move to closed loop control, the loop is closed by the condition detector. Included in the condition detector circuit is a timer whose cycle is RPM dependent. The timer will time out if the sensor has not indicated an operational capability in one timing cycle or a set number of RPM counts and will generate a signal indicating a sensor failure. After closing the loop, the detector circuit will check for a sensor transition on a periodic basis related to the authority of the integral controller and provide a signal to open the closed loop if the transition does not occur. A rich burst generator is provided to perturbate the loop periodically to produce a rich transition of the sensor if it is operable. A latching failure indicator circuit is additionally included in the system to energize a visual indicator and alert an operator if the failure condition occurs.

Closed loop sensor condition detector

A driver circuit for an electrical load device such as an indicator lamp includes the capability to both drive the lamp and to respond to a fault condition in the lamp to disable its energization. The circuit is adapted for control by a single I/O terminal of a programmable logic device. The I/O terminal being of the type having an internal architecture that causes the terminal to be pulled up to a logic high state when unloaded, and pulled down to a logic low state by either external loading or the closure of an internal; program-controlled switch forming part of a low-impedence path to ground. A processor-implemented test routine can be used to monitor the I/O terminal voltage and close the internal switch when the driver circuit responds to a shorted condition.

Driver circuit for an electrical load with capability for detecting a

An electronic control unit for regulating the air/fuel ratio of an internal combustion engine is disclosed. The electronic control unit includes an injector driver circuit which regulates the timing of the opening and closing operations of a plurality of electromagnetic solenoid injectors which input fuel to the engine. The injector driver circuit controls the injection with a pulse width modulated signal to supply an amount of fuel calculated from the operating parameters of the engine. The injector driver circuit is further provided with an energy dissipation circuit to assist in the rapid de-energization of the solenoid injectors. The energy dissipation circuit drains the energy stored in the rapidly collapsing magnetic field of a de-energized injector through a power device whose energy dissipation is controlled by the breakdown voltage of a Zener diode connected to the control terminal of the power device. The power device provides a variable conductance which dissipates an amount of energy proportional to the gain of the device times the amount of energy dissipated through the Zener diode. Preferably, the power device can be a final driver transistor used by the injector driver circuit to open and close the injectors.

Energy dissipation circuit for electromagnetic injection

An electronic control unit for regulating the air/fuel ratio of an internal combustion engine is disclosed. The electronic control unit has an open loop calibration for regulating the air/fuel ratio that is corrected with a closed loop correction signal developed by an integral controller. The open loop calibration is a speed-density based schedule which is combined with corrections for special conditions to account for the operating parameters of the engine at any instant. Included in these special condition corrections are provisions for an altitude compensation feature. The altitude compensation feature includes circuitry to modify the intake manifold pressure portion of the speed density schedule with two variables which depend on altitude. Power enrichment for the pressure schedule is provided as a function of altitude by lowering a power enrichment break point for increases in altitude and enrichment for all values of intake pressure is provided as a function of altitude to compensate for the internal EGR of the engine and to provide increased utilization for the closed loop controller.

Altitude compensation feature for electronic fuel management systems

Hybrid electronic control unit for fuel management systems

In an electronic fuel injection system for internal combustion engines a voltage multiplier is used to amplify a manifold absolute pressure signal by an amplification factor which is related to throttle position. A dc voltage related to throttle position is converted to a digital signal which controls a bilateral switch which in turn regulates the feed back resistance in an operational amplifier thus regulating the operational amplifier amplification factor. The manifold absolute pressure signal is amplified by the operational amplifier. The resultant signal determines the fuel injector open time.

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Newport News, VA, United States of America

Ralph W Carp