A controller performs a rotation angle deriving process that derives a value of the rotation angle of a crankshaft by each specified angle that is smaller than a predetermined angle by performing a Hilbert process on a detection signal from a crankshaft sensor, an angular velocity deriving process that derives an angular velocity of the crankshaft as an engine angular velocity from the value of the rotation angle of the crankshaft by each specified angle, an inertia torque calculation process that calculates an engine inertia torque from the engine angular velocity, a resonance effect torque calculation process that calculates a resonance effect torque, and an engine torque calculation process that calculates a sum of the resonance effect torque and the engine inertia torque as an engine torque that is an output torque of the engine.

A method for operating a drive device having a drive unit producing exhaust gas and an exhaust gas posttreatment device designed as a vehicle catalytic converter for posttreatment of the exhaust gas. A first measured value describing the residual oxygen content in the exhaust gas is measured by a first lambda sensor arranged upstream of the exhaust gas posttreatment device and a second measured value describing the residual oxygen content in the exhaust gas is measured by a second lambda sensor arranged downstream of the exhaust gas posttreatment device. The combustion air ratio of a fuel-air mixture used to operate the drive unit is set during an at least temporarily performed normal operating mode on the basis of the first measured value, the second measured value, and a threshold value for the second measured value.

A compression monitoring system for a reciprocating engine includes a controller configured to terminate combustion within a combustion chamber of the reciprocating engine while a crankshaft of the reciprocating engine is rotating. The controller is also configured to receive an input signal from a sensor indicative of vibration within a cylinder extending from the combustion chamber while the crankshaft is rotating and the combustion is terminated. Furthermore, the controller is configured to determine a magnitude of the vibration within a frequency range and to determine a maximum pressure within the cylinder based on the magnitude of the vibration within the frequency range. The controller is also configured to output an output signal indicative of the maximum pressure within the cylinder and/or control operation of the reciprocating engine based on the maximum pressure within the cylinder.

A CPU substitutes a difference between a crank-side speed that is a rotation speed of a crankshaft and a downstream-side speed that is a speed of a portion, opposite from the crankshaft, in a damper into a differential speed. The CPU calculates a torsion angle through a process of integrating the differential speed. The CPU calculates a torsion speed component that is a speed component of the crankshaft due to torsion of the damper based on a process of integrating a value obtained by multiplying the torsion angle by an elastic modulus, and calculates a time that is a variable indicating a speed of the crankshaft, used to determine a misfire, based on the torsion speed component. The CPU subtracts a value obtained by subtracting an output value of the integrating process, applied to a finite response low-pass filter process, from the output value.

A controller performs a rotation angle deriving process that derives a value of the rotation angle of a crankshaft by each specified angle that is smaller than a predetermined angle by performing a Hilbert process on a detection signal from a crankshaft sensor, an angular velocity deriving process that derives an angular velocity of the crankshaft as an engine angular velocity from the value of the rotation angle of the crankshaft by each specified angle, an inertia torque calculation process that calculates an engine inertia torque from the engine angular velocity, a resonance effect torque calculation process that calculates a resonance effect torque, and an engine torque calculation process that calculates a sum of the resonance effect torque and the engine inertia torque as an engine torque that is an output torque of the engine.

An energization control unit is configured to perform a constant current control by repeatedly switching between an on-state and an off-state of at least one upstream switch provided in an energization path of a coil of a fuel injection valve to control opening of the fuel injection valve in a drive period in which the coil is energized to drive the fuel injection valve. A current detection unit is configured to detect a coil current flowing through the coil. A valve-opening detection unit is configured to detect valve-opening timing of the fuel injection valve based on a change in at least one frequency spectrum of the coil current in a constant current control period in which the constant current control is performed. A valve-opening correction unit is configured to correct valve opening of the fuel injection valve based on a detection result of the valve-opening detection unit.

In as internal combustion engine control apparatus, an electronic control device is configured to subject a signal from a knock sensor to short-time Fourier transform, to thereby generate an observation matrix. Further, the electronic control device is configured to decompose the observation matrix into knocking vibration data being data on vibration caused by knocking and mechanical vibration data being data on vibration other than the knocking.

A feedback device for use in a gas turbine engine, and methods and systems for controlling a pitch for an aircraft-bladed rotor, are provided. The feedback device is composed of a circular disk and a plurality of position markers. The circular disk is coupled to rotate with a rotor of the gas turbine engine, to move along a longitudinal axis of the rotor, and has first and second opposing faces defining a root surface that extends between and circumscribes the first and second faces. The plurality of position markers extend radially from the root surface and are circumferentially spaced around the circular disk. The position markers have a top surface elevated with respect to the root surface and opposing first and second side surfaces. The side surfaces of the position markers have a curved concave profile extending toward the root surface.

A method for checking the function of a pressure sensor in the air intake tract or gas outlet tract of an internal combustion engine and to an engine control unit for carrying out the method and based on measuring dynamic pressure oscillations of the intake air or the exhaust gas by the relevant pressure sensor and, on the basis of the pressure oscillation signal obtained, respectively determining with the aid of a discrete Fourier transformation for a number of selected signal frequencies in each case a value of a specific operating characteristic of the internal combustion engine and deviation values of the values determined for the different signal frequencies from one another. Depending on whether deviation values determined fall below or exceed a predetermined limit value, the satisfactory function of the pressure sensor is confirmed, or a malfunction of the pressure sensor is diagnosed.

A method for operating an internal combustion engine, including aligning an injection behavior of the number of injectors. Aligning the injection behavior includes switching off one injector of the number of injectors, detecting a signal of the internal combustion engine that is to be assigned to the switched off injector, determining an alignment characteristic from the signal and assigning the alignment characteristic to the switched off injector as an alignment characteristic assigned to the injector, and switching on the previously switched off injector. Aligning the injection behavior further includes performing the aforementioned steps sequentially for the other injectors of the number of injectors and correcting a control of an injector that is to be corrected using the measured value assigned to the injector that is to be corrected.