Abstract: An electromagnetically operable fuel injector for a gaseous fuel injection system of an internal combustion engine, the injector having a generally longitudinal axis, which includes a ferromagnetic core, a magnetic coil at least partially surrounding the ferromagnetic core and an armature magnetically coupled to the magnetic coil and being movably responsive to the magnetic coil. The armature actuates a valve closing element in the form of a valve needle which interacts with a fixed valve seat of a fuel valve and is movable away from the fixed valve seat when the magnetic coil is excited. The fixed valve seat defines an aperture of predetermined dimension for passage of fuel therethrough, the armature having a generally elongated shape and a generally central opening for axial reception and passage of gaseous fuel from a fuel inlet connector positioned adjacent thereto.

Abstract: Sensing magnetic flux in an electromechanical actuator having dual axially opposed stators and dual springs, a control system modifies the rise of flux in such a manner to produce a substantially zero velocity landing of an armature against the stators. The flux is sensing by means of a sensor such as a hall effect sensor that is mounted each stator. The control system controls the flux rise when the armature is within the landing zone of the armature against the stator to match the spring rate of axially opposed springs in the actuator.

Abstract: A fuel injector apparatus includes an electromagnetic fuel injector having a housing and a magnetic circuit in the housing. The magnetic circuit including an electromagnetic coil constructed and arranged to operate at a nominal voltage to open the fuel injector. The nominal voltage is substantially less that a supply voltage. Circuit structure is electrically coupled with the coil and is constructed and arranged to step-down the supply voltage to be substantially the nominal voltage at the coil.

Abstract: A fuel injector apparatus includes an electromagnetic fuel injector having a housing and a magnetic circuit in the housing. The magnetic circuit includes a first coil having a certain resistance to generate a peak current and a second coil having a resistance greater than the certain resistance to generate a hold current. Circuit structure is disposed in the housing and is electrically coupled with the coils to selectively excite the coils. The circuit structure includes switch structure to transition the peak current to the hold current based on a preset threshold. In a preferred embodiment of the invention, the switch structure includes an RC circuit and a comparator which sets a threshold voltage. A time constant of the RC circuit is provided to be an analog model of an inductance and resistance time constant of the fuel injector such that when a voltage of a capacitor of the RC circuit exceeds the threshold voltage, the peak current is transitioned to the hold current.

Abstract: An electromagnetic actuator 10 includes first and second electromagnets 12 and 18, respectively. The second electromagnet 18 is in spaced relation with respect to the first electromagnet 12. An armature 24 is mounted for movement between the first and second electromagnets. An engaged position of the armature 24 is defined when the armature contacts one of the electromagnets 12 or 18 with an electrical signal to the contacted electromagnet being turned-off. Spring structure 30 is operatively associated with the armature 24 to bias the armature 24 away from the engaged position thereof. A piezoelectric device 34 is operatively associated with the armature 24 so that when the armature is in the engaged position and a force of the spring structure 30 is insufficient to move the armature from contact with the contacted electromagnet, the piezoelectric device 34 may be energized so as to move the armature 24 from contact with the contacted electromagnet.

Abstract: A bi-fuel injection system includes a source of first liquid fuel; a source of second liquid fuel; at least one variable vapor pressure fuel injector; a common fuel rail for supplying first or second fuels to the fuel injector; a first valve structure in selective communication with the source of first or second fuels and in communication with an inlet of the fuel rail to selectively control supply of one of the first and second fuels to the fuel rail; and a second valve structure in communication with an outlet of the fuel rail and in selective communication with the source of first or second fuels to return fuel exiting the fuel rail to the source of first or second fuels. The second valve structure may be in selective communication with a vapor purge system to receive fuel vapors exiting the fuel rail.

Abstract: There is shown an electric motor control of the engine valves of an internal combustion engine. A brushless torque actuator controls the rotation of a cam member which provides the appropriate lift to the engine valve to move the valve from the closed to the open position. The electronic control which is connected to the actuator includes a look-up table for controlling the timing of the engine in accordance with the operation of the internal combustion engine. The electronic control operates to return the cam member to its home position closing the engine valves.

Abstract: Opening and closing times of a fuel injector are accurately determined in accordance with the energy content of an accelerometer trace. The energy content of an accelerometer trace is determined in accordance with a predetermined relation. A line is defined between known points prior to and after the opening or closing time. The normal distance between the line connecting known points and the accelerometer trace energy content is maximum at the inflection point, which corresponds to the opening or closing time. With this data, an ECU can be properly programmed to more accurately control an injector stroke, thereby improving engine performance.

Abstract: Fuel pressure in a deadheaded fuel rail is regulated by an eddy current clutch that forms part of the mechanism that mechanically couples the engine crankshaft with a fuel pump which delivers pressurized fuel to the rail. An electric control that receives several inputs, including engine speed and fuel rail pressure, controls the degree of coupling that is provided by the clutch so that the pressure is regulated even though the engine speed and fuel demand change during normal engine operation.

Abstract: A cruise control sub-system is incorporated into an electronic throttle control system. The sub-system comprises a cruise control module that provides respective charge and discharge signals to a circuit for charging and discharging a capacitor. The voltage across the capacitor represents a cruise control signal and is supplied to a port of the electronic throttle control microprocessor. In the cruise control mode of operation, the microprocessor causes the throttle to be positioned by the cruise control signal. If the driver depresses the accelerator pedal to an extent that would command a throttle opening larger than that commanded by the cruise control signal, the microprocessor causes to throttle to be operated to the larger opening. When the cruise control mode of operation ceases, the throttle is controlled by the accelerator pedal alone. The microprocessor also performs testing of the cruise control sub-system and gives a fault indication if a fault is detected.

Abstract: Rather than having the two throttle position sensors connected directly to a common D.C. power supply, isoation circuits are connected between each sensor and the power supply so that a short in one sensor will be indicated to the ECU without adversely affecting the signal from the other sensor. The isolation circuits are simple RC circuits.

Abstract: The crystal-controlled oscillator circuit of the microprocessor comprises, for the starting resistance, a pair of discrete resistors connected in parallel. The two have respective resistance values which in their parallel circuit connection are effective to cause the initiation of electrical oscillation and which are also individually effective to cause the initiation of electrical oscillation so that in the event that one of the individual resistors experiences an open circuit fault, the oscillation can nonetheless be initiated by the other of the individual resistors. The invention provides improved reliability for automotive vehicle engine control systems.

Abstract: A unipolar motor control system includes motor current regulation derived from monitoring battery voltage and motor temperature. The monitored battery voltage and motor temperature are inputs to a microprocessor control which has one or more look-up tables for developing an appropriate scaling factor that adjusts the voltage across the motor coils so that proper current magnitude is delivered to the motor.

Abstract: Apparatus and method for integrating mass air flow for a specified cylinder event in the intake tract of an internal combustion engine. The respective outputs of a mass air flow sensor and a directional air flow sensor are used to determine an accurate net integrated value of mass air flow. The magnitude of mass air flow is sampled and electronically integrated several times during each specified engine event in either a positive or negative sense (depending upon air flow direction) to obtain a net mass air flow value, which is then input to a A/D converter and then a microprocessor in an engine electronic control unit for use in engine management control.

Abstract: Redundancy is imparted to the reset signal from a voltage regulator integrated circuit by connecting an RC timing circuit with the regulated voltage output and with the reset pulse output such that a reset pulse derived from the regulated output voltage is given in the event that the reset output of the integrated circuit fails to give a reset pulse. An over-/under-voltage detector monitors the regulated voltage output for also giving a reset signal in the event that the regulated output strays beyond allowable limits. The occurrence of a reset causes interruption of electric power to the throttle motor and of fuel to the engine.

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.