Abstract: A limited angle torque motor and control circuit are adapted to convert an electrical demand signal of varying magnitude into a motor shaft position relating to the magnitude of the demand signal. More particularly, a bidirectional motor is provided having two stator coils wound in phase opposition, so that the torques produced by the currents in the opposedly wound coils are summed such that the coil having the greater current controls the direction of rotor rotation. A position sensor provides feedback of the present shaft position; the magnitude of the feedback signal being indicative of motor shaft position. Finally, an electronic control circuit which is responsive to both the demand signal and the shaft position signal is provided and has two outputs for simultaneously driving the current in each respective stator coil. A summing means is included in the control circuit for combining the shaft position signal and demand signal so as to produce an error signal.

Abstract: An electronic fuel injection control system having a plurality of fuel injection valves, wherein each valve is operated by an electromagnetic solenoid. The control system includes at least one driver circuit for supplying current limited power to the solenoid, at least one control circuit for controlling the current passing through the solenoid, and a multiplexing means for selectively interconnecting the at least one driver circuit and the at least one control circuit to the terminals of a selected solenoid for selectively energizing the solenoid. The multiplexing means includes two switch arrays. The first switch array has at least one switch that selectively interconnects at least one driver circuit to a first terminal of the solenoids. The second switch array has at least one switch selectively interconnecting at least one control circuit to a second terminal of the solenoids.

Abstract: A system and method for closed loop control of a pressure-activated variable geometry turbocharger (VGT) for use in internal combustion engines, such as heavy duty diesel engines, provides sensors for detecting both intake manifold boost pressure as well as VGT actuator pressure. Sensors are also provided for detecting various engine operating parameters. Target VGT actuator pressures and target intake boost pressures are read from look-up tables according to the engine operating parameter values. Closed loop control of VGT geometry is effected based upon either VGT actuator pressure error or intake manifold boost pressure error as a function of engine operating mode, e.g., steady state or transient state operation. Turbine overspeed protection and adaptive compensation for transient state control are also performed.

Abstract: An electronic integrated engine and vehicle management and control system includes an electronic vehicle control module and a fuel injection control module, in communication with each other, which together control the total vehicle and engine operation functions of a heavy duty vehicle. A novel fuel injection timing device is utilized with the control module to allow precise and sophisticated control of engine timing based on a number of engine and vehicle operating parameters as determined by the control modules. Functions such as engine speed control, vehicle road speed control, engine protection shutdown, fuel economy, braking control and diagnostics are performed by the system.