A closed-loop control device, for closed-loop control of a power assembly including an internal combustion engine and a generator having an operative drive connection to the internal combustion engine, includes: the closed-loop control device which is configured for: detecting a generator power (P.sub.G) of the generator as a controlled variable; determining a control deviation (e.sub.P) as a difference between the generator power (P.sub.G) which is detected and a target generator power (P.sub.soll); determining a target speed (n.sub.soll) as a manipulated variable for controlling the internal combustion engine as a function of the control deviation (e.sub.P); using a control rule for determining the target speed (n.sub.soll); and being operatively connected to an open-loop control device of the internal combustion engine in such a way that the target speed (n.sub.soll) can be transmitted by the closed-loop control device to the open-loop control device.

A fuel injection control device includes: an energization control unit that controls a fuel injection valve; an inter-terminal voltage acquiring unit that acquires an inter-terminal voltage of the fuel injection valve at a predetermined time interval; and a state determining unit that determines an open-close operation state of the fuel injection valve based on the acquired inter-terminal voltage, wherein the state determining unit sets, for each of the plurality of fuel injections in the fuel injection period, a valve closing determination period after the electricity to the fuel injection valve is turned off, the period having a time length determined according to a number of injection stages of the multi-stage injection, and determines that the fuel injection valve is in a fully closed state when the voltage change due to a valve body movement of the fuel injection valve appears in the inter-terminal voltage acquired in the valve closing determination period.

A vehicle for agricultural use has wheel groups, an engine group, an engine control unit, auxiliary operating groups, a gearbox group, a power take-off group, and a detection system having an engine power detector for detecting an engine power value, an auxiliary power detector for detecting an auxiliary power value, a drive power detector for detecting a drive power value, and an operating unit operatively connected to the detectors to receive the engine power value, auxiliary power value, and drive power value and suitable for identifying a take-off power value corresponding to power used by the power take-off group. The operating unit checks the drive power value with respect to a drive threshold value and/or the power take-off power value with respect to a power take-off threshold value and is connected to the engine control unit to control supply of the engine group as a function of check results.

Various embodiments of the present disclosure are directed towards free-piston combustion engines. As described herein, a method and system are provided for displacing a free-piston assembly to achieve a desired engine performance by repeatedly determining position-force trajectories over the course of a propagation path and effecting the displacement of the free-piston assembly based, at least in part, on the position-force trajectory. In a dual-piston assembly free-piston engine, synchronization of the two piston assemblies is provided.

A closed-loop control device, for closed-loop control of a power assembly including an internal combustion engine and a generator having an operative drive connection to the internal combustion engine, includes: the closed-loop control device which is configured, in a first functional state, for: detecting a generator frequency (f.sub.G) of the generator as a controlled variable; determining a control deviation (e.sub.f) as a difference between the generator frequency (f.sub.G) which is detected and a target generator frequency f.sub.soll); determining a target speed (n.sub.soll) as a manipulated variable for controlling the internal combustion engine as a function of the control deviation (e.sub.f); using a control rule for determining the target speed (n.sub.soll); and being operatively connected to an open-loop control device of the internal combustion engine in such a way that the target speed (n.sub.soll) can be transmitted by the closed-loop control device to an open-loop control device.

Various embodiments include a method for actuating a piezo actuator of an injection valve of a fuel injection system comprising: determining actuation signals for the piezo actuator using a stored current/voltage characteristic curve for carrying out an injection process; detecting the profile of the current flowing through the piezo actuator during the injection process and the profile of the voltage applied to the piezo actuator during the injection process; adapting the stored current/voltage characteristic curve based at least in part on the detected current profile and the detected voltage profile; and determining actuation signals for the piezo actuator using the stored, adapted current/voltage characteristic curve for carrying out a subsequent injection process.

The disclosure describes a system that includes a closed-loop reference module, an adaptation module, and a control module. The closed-loop reference module is configured to execute a reference model that represents operation of an engine and determine a reference control signal and a reference state trajectory signal. The adaptation module is configured to determine an adaptation signal based on a difference between the reference state trajectory signal and an engine state trajectory signal representative of actual operation of the engine. The control module is configured to receive the reference control signal from the closed-loop reference module, the adaptation signal from the adaptation module, and the engine state trajectory signal. The control module is further configured to determine a demand signal based on the engine state trajectory signal, the adaptation signal, and the reference control signal, and output the demand signal to control operation of at least one engine component.

A controller for an internal combustion engine includes processing circuitry. The processing circuitry executes a fuel cut-off process that stops supply of fuel to a combustion chamber of the internal combustion engine when an accelerator operation amount is less than or equal to a predetermined amount and a rotation speed of a crankshaft is in a predetermined speed range. The processing circuitry executes an widening process that widens the predetermined speed range when a decrease rate of the rotation speed of the crankshaft is less than or equal to a specified rate as compared to when the decrease rate is greater than the specified rated.

Various embodiments of the present disclosure are directed towards free-piston combustion engines. As described herein, a method and system are provided for displacing a free-piston assembly to achieve a desired engine performance by repeatedly determining position-force trajectories over the course of a propagation path and effecting the displacement of the free-piston assembly based, at least in part, on the position-force trajectory. In a dual-piston assembly free-piston engine, synchronization of the two piston assemblies is provided.

One embodiment is a method of operating an electronic control system (ECS) to control an engine to propel a vehicle. The method comprises receiving a throttle command, determining an operation to increase engine cycle efficiency by reducing engine torque below a magnitude corresponding to the throttle command and below a torque curve limit over a first vehicle operation segment and permitting an increase in engine torque above the torque curve limit over a second vehicle operation segment, controlling the engine to output torque below the magnitude corresponding to the throttle command and below the torque curve limit over the first vehicle operation segment, and controlling the engine to output torque above the torque curve limit over the second vehicle operation segment in response to a second received throttle command and constrained by an extended limit on operation of the engine above the torque curve limit.