Abstract: A control system for controlling pilot fuel injection in a dual fuel engine is disclosed. The control system may determine, using measurements from one or more sensors, one or more combustion parameters associated with the dual fuel engine during operation of the dual fuel engine. The control system may determine an estimated nitrogen oxides (NOx) emissions level based on the one or more combustion parameters, and may determine a NOx error based on a comparison between the estimated NOx emissions level and a desired NOx emissions level. The control system may control a quantity of pilot fuel injected into the dual fuel engine based on the NOx error.

Abstract: A control system for controlling pilot fuel injection in a dual fuel engine is disclosed. The control system may determine, using measurements from one or more sensors, one or more combustion parameters associated with the dual fuel engine during operation of the dual fuel engine. The control system may determine an estimated nitrogen oxides (NOx) emissions level based on the one or more combustion parameters, and may determine a NOx error based on a comparison between the estimated NOx emissions level and a desired NOx emissions level. The control system may control a quantity of pilot fuel injected into the dual fuel engine based on the NOx error.

Abstract: The disclosure relates to a system and method for determining the specific gravity of a fuel used in a dual fuel engine. The system includes a fuel rail, at least one sensor, and a processor. The method includes sensing and recording, with the at least one sensor and the at least one memory, a first pressure profile of a first fuel in the fuel rail and a second pressure profile of a second fuel in the fuel rail. The first fuel has a known specific gravity and the second fuel has an unknown specific gravity. The method further includes calculating the second specific gravity of the second fuel, with a processor, based on the first pressure profile, the second pressure profile, and the first specific gravity.

Abstract: A method for controlling fuel flow in a multi-fuel engine is disclosed. The method includes determining an estimated lower heating value (LHV) of a gaseous fuel by, at least, comparing a mapped volume flow value with an input volume flow value, the input volume flow value based on the input power. The method further includes determining a gaseous fuel flow rate for the gaseous fuel, the gaseous fuel flow rate based on, at least, a specific fuel substitution ratio of the gaseous fuel and a secondary fuel and the estimate LHV of the gaseous fuel source.

Abstract: The disclosure relates to a system and method for determining the specific gravity of a fuel used in a dual fuel engine. The system includes a fuel rail, at least one sensor, and a processor. The method includes sensing and recording, with the at least one sensor and the at least one memory, a first pressure profile of a first fuel in the fuel rail and a second pressure profile of a second fuel in the fuel rail. The first fuel has a known specific gravity and the second fuel has an unknown specific gravity. The method further includes calculating the second specific gravity of the second fuel, with a processor, based on the first pressure profile, the second pressure profile, and the first specific gravity.

Abstract: Controlling intake pressure in a gaseous fuel internal combustion engine includes calculating a control term in an intake pressure control loop based on a pressure error, and adjusting a throttle valve and a second valve responsive to the control term in first and second control loop cycles. The second valve is within a return conduit returning compressed gases from a location downstream a compressor to a location upstream. A pressure of gaseous fuel and air within the intake conduit is changed via the adjustments so as to reduce the pressure error.

Abstract: A first target wheel has an opening and rotates about an axis of rotation to move the opening along a generally circular path. A second target wheel adjacent the first target wheel has a second projection projecting into the opening of the first target wheel with the second projection being movable along the generally circular path. A single sensor is positioned adjacent the generally circular path and senses movement of the opening and the second projection past the sensor. An electronic controller may be used to process signals from the sensor to determine the relative angular difference between the first target wheel and the second target wheel.

Abstract: A first target wheel has an opening and rotates about an axis of rotation to move the opening along a generally circular path. A second target wheel adjacent the first target wheel has a second projection projecting into the opening of the first target wheel with the second projection being movable along the generally circular path. A single sensor is positioned adjacent the generally circular path and senses movement of the opening and the second projection past the sensor. An electronic controller may be used to process signals from the sensor to determine the relative angular difference between the first target wheel and the second target wheel.

Abstract: A control system for determining and controlling position and velocity of a valve member relative to a valve contact surface in a valve system preferably having an actuator comprised of a piezoelectric device. The control system includes an actuator control circuit for applying a control signal to the actuator to move the member relative to the contact surface. The control system further includes a seat detection circuit for determining when the member impacts the contact surface. The control system further includes a velocity control circuit which utilizes the output of the seat detection circuit from the previous actuation cycle to control the position and velocity of the member relative to the contact surface in the subsequent actuation cycle.