Methods and systems are presented for assessing the presence or absence of engine torque deviation which may indicate air-fuel ratio imbalance between engine cylinders. In one example, the method may include assessing the presence or absence of engine torque variation based on engine torque deviation from a desired engine torque during a deceleration fuel shut-off event.

The embodiments relate to a method and to a device for operating a system including a generator and an internal combustion engine driving the generator, wherein a rotational speed of the generator is controlled by a rotational speed controller. In the method, the rotational speed controller outputs a target torque as manipulated variable, and an additional torque is imposed on the target torque, wherein the additional torque is calculated or is determined based on a measured value picked up from the system.

Fuel reform apparatus includes: internal combustion engine including injector and configured so that compression-ignition combustion is carried out in combustion chamber; reform unit interposed in fuel supply path from fuel tank to injector and including reformer reforming fuel stored in fuel tank by oxidation reaction; and controller including CPU and memory. Controller performs: estimating progress level of oxidation reaction in reformer; and controlling operation of reform unit based on progress level of oxidation reaction estimated.

A misfire detection device for an internal combustion engine is provided. A mapping takes time series data of instantaneous speed parameters as inputs. Each instantaneous speed parameter corresponds to one of a plurality of successive second intervals in a first interval. The instantaneous speed parameters correspond to the rotational speed of the crankshaft. The first interval is a rotational angular interval of the crankshaft in which compression top dead center occurs. The second interval is smaller than an interval between compression top dead center positions. The mapping outputs a probability that a misfire has occurred in at least one cylinder that reaches compression top dead center in the first interval. The mapping data defining the mapping has been learned by machine learning.

Methods and systems are provided for maintaining combustion stability in a multi-fuel engine. In one example, a system may include first and second fuel systems to deliver liquid and gaseous fuels, respectively, to at least one cylinder of the engine, and a controller. The controller may be configured to supply the gaseous fuel to the at least one cylinder, inject the liquid fuel to the at least one cylinder to compression ignite the liquid fuel and combust the gaseous fuel in the at least one cylinder, and retard an injection timing of the injection of the liquid fuel based on a measured parameter associated with auto-ignition of end gases subsequent to the compression-ignition of the liquid fuel. In some examples, the controller may further be configured to adjust an amount of the gaseous fuel relative to an amount of the liquid fuel based on the measured parameter.

Methods and systems are provided for maintaining combustion stability in a multi-fuel engine. In one example, a system may include first and second fuel systems to deliver liquid and gaseous fuels, respectively, to at least one cylinder of the engine, and a controller. The controller may be configured to supply the gaseous fuel to the at least one cylinder, inject the liquid fuel to the at least one cylinder to compression ignite the liquid fuel and combust the gaseous fuel in the at least one cylinder, and retard an injection timing of the injection of the liquid fuel based on a measured parameter associated with auto-ignition of end gases subsequent to the compression-ignition of the liquid fuel. In some examples, the controller may further be configured to adjust an amount of the gaseous fuel relative to an amount of the liquid fuel based on the measured parameter.

Methods, systems, and devices for managing motor torque smoothing for internal combustion engine cylinder recharging events are described herein. An engine controller in a vehicle for managing motor torque smoothing for internal combustion engine cylinder recharging events may be configured to operate the internal combustion engine at a firing fraction that is less than a value of 1.0, wherein one or more cylinders are not designated to be fired, determine a recharge event time period where a particular one of the cylinders that have not been designated to be fired is recharged, identify a disruption quantity of torque during the recharging event time period, and actuate an additional motor to initiate a supplemental quantity of torque during the recharge event time period based on the disruption quantity of torque.

A fuel metering system for an internal combustion engine having a fuel injection timing unit to indicate a timepoint during one or more engine strokes, a fuel metering element have a predetermined full stroke volume for metering fuel into an air-fuel mixing location during one or more of the engine strokes, and a fuel metering element controller to control the delivery of fuel by causing the fuel metering element to deliver one of a full stroke volume and a fraction of a full stroke volume to achieve a desired AFR. In some embodiments, power generator circuitry is provided to harvest power from the ICE to power at least one of the fuel injection timing unit, the fuel metering element, and the fuel metering controller.

Disclosed is a method for controlling a speed of a vehicle combustion engine, the engine including at least one combustion chamber, into which a mixture of air and fuel is injected, and an air box, configured to inject the air into the combustion chamber and having an air flow rate controlled by a regulating butterfly valve, the regulating butterfly valve having a variable angular position, controlled by a predetermined position of an actuator. The method includes the steps of evaluating a so-called “load” resistant torque resulting from a plurality of external loads applied to the engine, determining, from the calculated load resistant torque, a position of the actuator, so as to determine an angular position of the regulating butterfly valve, and controlling the position of the actuator, so as to control the engine speed.

Disclosed is a method for regulating the speed of an engine which drives a disengageable device. The regulation of the engine speed is effected in accordance with a first mode when the disengageable device is disengaged and in accordance with a second mode when the disengageable device is engaged. The determination is effected by: —estimating the resistive torque exerted on the engine by the disengageable device; —changing a binary value from a first value representative of the disengaged state to a second value representative of the engaged state when the estimated resistive torque is higher than a first predetermined threshold for a first predetermined period of time; and —changing the binary value from the second value to its first value when, for a second predetermined period of time, the estimated resistive torque is lower than a second threshold possibly equal to the first threshold.