Abstract: Disclosed is a way to detect ionization within a cylinder of an internal combustion engine where the engine selectively operates in either a spark ignition mode or a HCCI mode. A single ionization detector circuit adapts in response to a control input to alter its bias voltage and its gain to selectively enable effective detection of ionization for each of two different operational modes of an internal combustion engine.

Abstract: Disclosed is a way to detect ionization within a cylinder of an internal combustion engine where the engine selectively operates in either a spark ignition mode or a HCCI mode. A single ionization detector circuit adapts in response to a control input to alter its bias voltage and its gain to selectively enable effective detection of ionization for each of two different operational modes of an internal combustion engine.

Abstract: An engine control apparatus is disclosed for determining crankshaft position and engine phase of an internal combustion engine through monitoring intake air pressure fluctuations. The opening of the intake valve is mechanically linked to the crankshaft position of an engine. When the intake valve opens it creates air pressure fluctuations in the air induction system of the engine. The control apparatus is configured to determine intake air pressure fluctuations indicative of an intake air event and thus a particular crankshaft position, and their corresponding period of the engine cycle. The controller then uses this information to determine crankshaft speed and position for the purpose of fuel injection and ignition timing of the internal combustion engine. Engine phase is also determined on four-stroke engines. The engine may also include a crankshaft position sensor in combination with monitoring intake air pressure fluctuations to increase resolution in determination of crankshaft position.

Abstract: An improved mass flow sensor interface (“MFSI”) circuit and method are disclosed for sensing and measuring mass flow rate of a gas and provide an output voltage proportional to the mass flow rate in a mass flow controller. The improved MFSI circuit of the present invention includes upstream and downstream mass flow sense elements a precision current source to drive the circuit. The circuit further includes an operational amplifier to sum the voltage upstream of the upstream sense element with the voltage downstream of the downstream sense element. A reference voltage is electrically connected to the positive node of the operational amplifier. An upstream shunting resistor and a downstream shunting resistor share a common junction at the negative node of the operational amplifier and are electrically connected in parallel to the upstream and downstream mass flow sense elements.

Abstract: A system and method for generating a linearized sensor signal p from a sensor signal m using a kth-degree polynomial The coefficients of the kth-degree polynomial can be calculated using a least-squares method by a computer. The computer can calculate for 1<j≦k the (2j−1) root of the jth coefficient aj of the kth-degree polynomial and download the coefficients and the resulting roots rj to a storage device in a digital signal processor (DSP).

Abstract: A system and method for a pulse width modulated (PWM) solenoid driver with a reduced rate of power consumption. The system for driving a solenoid includes a solenoid, a current set-point for establishing a desired current flow through the solenoid, and a step-down regulator circuit for controlling the current through the solenoid based on the difference between the desired current flow and the actual current flow through the solenoid. The step-down regulator circuit has a low internal resistance of not greater than approximately 1 ohm which contributes to the reduced rate of power consumption for the PWM solenoid driver.

Abstract: A supervisory circuit for an anti-lock brake system (ABS) unit. The circuit includes an independent internal voltage reference source that provides power to the circuit components. The circuit also includes an external power source monitor powered by the internal voltage reference source which inhibits the ABS unit when an external power source voltage exceeds a predetermined level. The circuit also includes a system voltage monitor powered by the internal voltage reference source that inhibits the ABS unit when a system voltage deviates from predetermined system voltage parameters. The circuit also includes an electronic control unit (ECU) monitor powered by the internal voltage reference source that monitors a periodic signal generated by an ECU and that inhibits the ABS unit if an ECU timing signal deviates from a predetermined threshold level. The supervisory circuit helps to prevent spurious operation of ABS modulators due to race conditions.

Abstract: A J-K flip/flop type storage register includes an input register and an output register. The input register is active when a clock pulse applied thereto is below a predetermined level defining a logic 0 state and inactive when the clock pulse signal is above the first predetermined level. The output register is active when the level of the clock pulse signal is above a second predetermined level and inactive when the clock pulse signal is below the second predetermined level. There exists a well-defined voltage range during which both the input and output registers are inactive. The transfer of information from the input register to the output register only occurs during the transition from a logic 0 level to a logic 1 level clock pulse signal. The SET and RESET inputs are only enabled when the clock pulse signal is at a logic 0 level.

Abstract: Improvements in vehicle antilock braking systems of the type having an operator controlled master cylinder (11) and a second source (55, 57) of pressurized hydraulic fluid for selectively supplying rebuild pressure after an antilock event are disclosed. The improved system is selectively operable in one of three braking modes, a normal braking mode (119) where braking force is proportional to an operator brake pedal pressure, an enhanced anti-skid braking mode (69) where braking force may be maintained at a maximum nonskid level, and a conventional anti-skid braking mode (71) where braking force follows a cyclic pattern of fluid pressure bleed and build. The system includes circuitry (17, 19, 35, 37, 93, 95) for determining the speed of each wheel and an arrangement (59) operable independently of any vehicle wheels for determining vehicle deceleration. This comparison normally invokes the enhanced anti-skid braking mode.

Abstract: Improvements in vehicle antilock braking systems of the type having an operator controlled master cylinder (11) and a second source (55, 57) of pressurized hydraulic fluid for selectively supplying rebuild pressure after an antilock event are disclosed. The improved system is selectively operable in one of three braking modes, a normal braking mode (119) where braking force is proportional to an operator brake pedal pressure, an enhanced anti-skid braking mode (69) where braking force may be maintained at a maximum nonskid level, and a conventional anti-skid braking mode (71) where braking force follows a cyclic pattern of fluid pressure bleed and build. The system includes circuitry (17, 19, 35, 37, 93, 95) for determining the speed of each wheel and an arrangement (59) operable independently of any vehicle wheels for determining vehicle deceleration. This comparison normally invokes the enhanced anti-skid braking mode.

Abstract: A speed signal conditioning and test circuit includes a comparator which is connected to a digital input port of a microprocessor and which switches its output in response to the alternating current generated by the sensor when sensing wheel speed. A test sequence is initiated by injecting a signal into a tuned circuit formed by the inductance of the sensor coil, the filtering capacitors, and associated circuit resistances. The voltage output of the tuned circuit increases exponentially and switches the comparator to provide a test pulse of a predetermined time period. The microprocessor times the pulse to establish that an operative sensor is present. Since the inductance of the coil is switched out of the circuit in the case of an open or shorted sensor coil, no pulse is generated and the microprocessor accordingly determines that a defective sensor is present.

Abstract: Vehicle antilock braking systems having an operator controlled master cylinder (11) and a second source (55, 57) of pressurized hydraulic fluid for selectively supplying rebuild pressure after an antilock event are disclosed. The system is selectively operable in one of three braking modes, a normal braking mode (119) where braking force is proportional to an operator brake pedal pressure, an enhanced anti-skid braking mode (69) where braking force may be maintained at a maximum nonskid level, and a conventional anti-skid braking mode (71) where braking force follows a cyclic pattern of fluid pressure bleed and build. The system includes circuitry (17, 19, 35, 37, 93, 95) for determining the speed of each wheel and an arrangement (59) operable independently of any vehicle wheels for determining vehicle deceleration.

Abstract: A brake pressure control mechanism for establishing a pressure level in a brake actuator includes a valve controlled by the current in a solenoid coil. The current in the coil is controlled in a first mode by switching the current in the coil off and on and allowing the current to increase and decay in the normal manner. However, when a fast decrease in brake pressure is demanded, the fly-back voltage across the coil is allowed to rapidly increase to a level greater than and in opposition to the voltage applied to the coil, thereby quickly driving the current lower. Current is driven to zero in the case of a fast brake pressure decay being demanded by the adaptive braking system or when the vehicle operator releases the brakes. When the error signal demands a fast decay, the fast decay mode is initiated and then returned to the normal control when the error between the demanded braking pressure and the pressure corresponding to the current of the coil is back within predetermined limits.

Abstract: A transducer is utilized to convert the eccentricity of a turbine shaft into a sinusoidal electrical voltage signal having a given frequency, amplitude and a DC bias. This electrical signal is provided to a circuit which periodically measures the maximum and minimum peaks of the sinusoidal signal. The frequency at which the latter measurements occur is related to the frequency of the sinusoidal input signal. The maximum and minimum levels of magnitude are stored periodically as DC levels and subtracted from each other to determine the absolute value of eccentricity. In addition the stored minimum value is compared with the sinusoidal signal to reduce the DC bias of the sinusoidal signal to a point where the negative peaks thereof are at zero.

Abstract: A decoder for converting a frequency coded digital input signal into a binary output signal. The decoder includes circuitry which detects when the input signal consists of the proper tones. When these tones are present, the decoder circuitry converts the tone signals into constant amplitude squarewave signals. The squarewave signals are then attenuated and integrated, and these two signals are offset and applied to a comparator. The resulting signal from the comparator is in the form of a pulse signal having rectangular pulses of constant amplitude and width, with the repetition rate of the pulses being equal to the corresponding tone frequency. The rectangular pulse signal is filtered and converted into a binary signal having binary levels which correspond to the average value of the filtered pulse signal with respect to an adjustable reference value.

Abstract: An arrangement of components for a distribution line communication system. Two or more independent secondary distribution lines are connected, through distribution transformers, to a primary distribution line. Carrier communication signals are transferred between the primary distribution line and one of the secondary distribution lines by a repeater located near one of the transformers. The carrier communication signals are propagated directly along this secondary distribution line and through associated service lines to communications terminals located near the electrical loads. Coupling apparatus is connected between the two independent secondary distribution lines to provide a path for the communication signals between the repeater and the communications terminals associated with the other secondary distribution line. The coupling apparatus provides a low-impedance path for the communication signals and a high-impedance path for signals at conventional electrical power frequencies.

Abstract: Apparatus for connecting separate transmitters of a carrier communication system to the same location on a power distribution line. A low-power transmitter is connected to the primary winding of an interconnecting transformer. The secondary winding of the interconnecting transformer is connected between a high-power transmitter and, through the primary winding of a coupling transformer, to ground potential. The secondary winding of the coupling transformer is coupled to the power distribution line. A voltage limiting device is connected across the secondary winding of the interconnecting transformer. The output of the high-power transmitter is directed across the voltage limiting device to the coupling transformer where it is applied to the distribution line.