An hydraulic system for a working machine, the system comprising an engine, and an engine speed sensor configured to detect the engine speed; a travel pump configured to actuate a travel actuator, and a travel pump pressure sensor configured to detect the travel pump pressure; a service pump configured to actuate a service actuator, and a service pump pressure sensor configured to detect the service pump pressure; and a micro-controller unit configured to receive input values from each sensor, and configured to determine whether each input value is within a predetermined range where the engine will not stall. The micro-controller unit is configured to provide an output when at least one input value is outside the predetermined range.

A powertrain system including an electric machine rotatably coupled to a crankshaft of an internal combustion engine via a belt is described, wherein the electric machine is disposed to generate torque. A method for controlling the electric machine includes monitoring rotational position of the electric machine, and periodically executing a speed observer to determine a rotational speed of the electric machine based upon the monitored rotational position of the electric machine. An acceleration observer is periodically executed to determine an acceleration rate, wherein the acceleration rate is determined based upon a time-based change in the rotational speed of the electric machine. A virtual inertia term is determined based upon the acceleration rate, and a torque compensation term is determined based upon the virtual inertia term and the acceleration rate. The electric machine is controlled to generate torque based upon the torque compensation term.

A powertrain system including an electric machine rotatably coupled to a crankshaft of an internal combustion engine via a belt is described, wherein the electric machine is disposed to generate torque. A method for controlling the electric machine includes monitoring rotational position of the electric machine, and periodically executing a speed observer to determine a rotational speed of the electric machine based upon the monitored rotational position of the electric machine. An acceleration observer is periodically executed to determine an acceleration rate, wherein the acceleration rate is determined based upon a time-based change in the rotational speed of the electric machine. A virtual inertia term is determined based upon the acceleration rate, and a torque compensation term is determined based upon the virtual inertia term and the acceleration rate. The electric machine is controlled to generate torque based upon the torque compensation term.

The engine shut-off valve system includes a housing, a gate member, a rotating lever, a locking piston assembly, and a closing piston assembly. The system is installed in fluid connection with a flow line so that air flow passes through a passageway in the housing with the gate member in the locked configuration. The air flow through the passageway stops with the gate member in the closed configuration. The gate member has an asymmetry so that the forces of the spring of the closing piston assembly and the spring of the locking piston assembly are cooperative to actuate between the closed configuration and the locked configuration, while wearing on the gate member differently so as to extend the working life of the valve system. The closing piston assembly and the locking piston assembly are separately accessible for maintenance.

In at least some implementations, a method of controlling engine idle speed includes comparing engine speed to a speed threshold where the speed threshold may include a range of speeds, if the engine speed is outside of the speed threshold, adjusting the timing of an ignition spark up to a threshold amount of ignition timing adjustment, and if the engine speed is not within said speed threshold after adjustment up to the threshold amount of ignition timing adjustment then adjusting the air/fuel mixture provided to the engine to bring the engine speed within said speed threshold.

According to an embodiment of the present disclosure, the gas engine heat pump includes: an engine including an ignition plug for burning a mixture of air and fuel; a compressor connected to the engine, for compressing refrigerant by an operation of the engine; a mixer for mixing the air and the fuel and supplying the mixture to the engine; a zero governor having a valve, for regulating the amount of fuel supply to the mixer; a throttle valve disposed between the mixer and the engine, for regulating the flow of the mixture entering the engine; and a controller, wherein the controller checks a current number of revolutions of the engine upon receiving a command to stop running the engine, changes a target number of revolutions of the engine so that the current number of revolutions of the engine reaches a first reference number of revolutions, if the current number of revolutions of the engine exceeds the first reference number of revolutions, controls the opening degree of the valve included in the zero governor in response to the change in the target number of revolutions of the engine, and controls the ignition plug to stop igniting if the current number of revolutions of the engine reaches a second reference number of revolutions which is lower than the first reference number of revolutions.

Systems and methods are provided for controlling a power plant during use of a power take-off (PTO) device, wherein the responsiveness and stability of the controller are adjustable by an operator in the field. The use of setting maps allows fine tuning of controller responsiveness while also ensuring that expected performance would be achieved at any setting within the setting map. In some embodiments, a proportional-integral-derivative (PID) controller is used to control engine speed, and gains for the proportional, integral, and derivative terms are obtained from setting maps based on a responsiveness setting chosen by a vehicle operator.

In a method and a device for operating an internal combustion engine, with at least one cylinder (Z1-Z4) having a combustion chamber (26), fuel is injected into the cylinder and a logic value (LV_FCUT) is set, in particular for stopping the injection of fuel into the cylinder, The method furthermore has the following steps: depending on a course of the highly time-resolved measurement signal of a rotational speed (N_FAST) of the internal combustion engine, a local maximum value (N_FAST_MAX) of the rotational speed is determined, a rotational speed difference (N_FAST_DIF) between the local maximum value (N_FAST_MAX) and a current measured value (N_FAST_MES) of the rotational speed is determined, and, depending on the determined rotational speed difference (N_FAST_DIF), the logic value (LV_FCUT) is set.

A handheld work apparatus has a combustion engine (4) for driving a tool. The combustion engine (4) has an ignition device, a device for metering fuel and a control device (31). The control device (31) engages when an engagement speed (n.sub.E1, n.sub.E2) is reached, in order to limit the speed (n) of the combustion engine (4). In order to allow the speed (n) to be set in an easy manner at full throttle, the work apparatus has a device for setting the engagement speed (n.sub.E2) by the user.

A handheld work apparatus has a combustion engine (4) for driving a tool. The combustion engine (4) has an ignition device, a device for metering fuel and a control device (31). The control device (31) engages when an engagement speed (n.sub.E1, n.sub.E2) is reached, in order to limit the speed (n) of the combustion engine (4). In order to allow the speed (n) to be set in an easy manner at full throttle, the work apparatus has a device for setting the engagement speed (n.sub.E2) by the user.