Methods and systems are provided for a multi-fuel engine. In one example, a method includes adjusting a substitution ratio based on an intake manifold temperature. The method further including adjusting the intake manifold temperature to increase the substitution ratio.

A method and apparatus controlling the fuel-to-air ratio of a fuel and air mixture supplied to an operating engine includes the steps of determining a first engine speed before enleanment of the mixture, determining a second engine speed near or at the end of a period of enleanment of the mixture, and after ending the enleanment, determining whether the engine speed recovers within a predetermined range of the first engine speed and if so determining a delta speed difference between the first and second speeds and using this delta speed difference as a factor in determining a change in the fuel-to-air ratio of the fuel mixture supplied to the engine.

A system includes an engine, a transmission driven by the engine, and a controller. The controller is configured to receive a speed input, receive feedback indicative of a load of the engine at a current engine speed, compare the load to a predetermined load threshold at the current engine speed, determine an expected engine speed based at least on the current engine speed, a current gear ratio, and an expected gear ratio, determine an estimated engine power at the expected engine speed and a current engine power at the current engine speed, and command a gear downshift when the load is greater than or equal to the predetermined load threshold and when the estimated engine power is greater than the current engine power.

While providing the control such that the air excess ratio falls within the stoichiometric range, if the throttle opening degree control means determines that a value of the torque is smaller than A [Nm], the throttle opening degree control means provides a first control of controlling the opening degree of the intake throttle valve such that the output shaft rotates at a constant first rotation number. If the throttle opening degree control means determines that the value of the torque is larger than A [Nm], the throttle opening degree control means provides a second control of controlling the opening degree of the intake throttle valve such that the rotation number of the output shaft becomes larger.

A method for maintaining an engine speed of an engine of a work vehicle includes sending a requested parameter indicative of the engine speed to an engine controller of the work vehicle. The method also includes receiving a measured parameter indicative of the engine speed. The method further includes determining whether the requested parameter is different from the measured parameter. The method also includes setting a controller-requested parameter indicative of the engine speed based at least in part on the requested parameter and the measured parameter. The method further includes sending the controller-requested parameter to the engine controller. The method accounts for speed and torque saturation in order to avoid windup in the controller.

A method for controlling power takeoff (PTO) clutch engagement includes determining an output clutch speed, adjusting a clutch current at a predetermined rate, estimating an inertial load of a PTO implement and adjusting the clutch current for one or more times at a time interval, and selecting a clutch control algorithm configured for the inertial load of the PTO implement.

A method for controlling PTO clutch engagement includes determining a first change in clutch speed based on an inertial load of a PTO implement. The method also includes determining a second change in clutch speed based on a threshold amount of energy of a PTO clutch. The method further includes determining a third change in clutch speed between the first change in clutch speed and the second change in clutch speed. The method also includes adjusting a clutch current based on the third change in clutch speed.

An agricultural vehicle includes an engine, a transmission driven by the engine, and a controller. The controller, in operation, adjusts a gear ratio of the transmission using an algorithm. The algorithm, in operation, performs the following steps: reduce a torque capacity of a first offgoing clutch of the transmission to a first torque target, reduce the torque capacity of the first offgoing clutch to a second torque target while adjusting the torque capacity of a first oncoming clutch of the transmission to a third torque target, such that the gear ratio of the transmission is modified in a first direction, and increase the torque capacity of the first oncoming clutch to a desired torque capacity.

A method for setting an engine speed of an internal combustion engine in a marine propulsion device to an engine speed setpoint includes receiving an operator demand from an input device and learning an adapted maximum engine speed. An engine speed setpoint is calculated by scaling the adapted maximum engine speed relative to the operator demand. The method includes predicting a position of a throttle valve of the engine that is needed to achieve the engine speed setpoint, and determining a feed forward signal that will move the throttle valve to the predicted position. A marine propulsion system has an electronic control unit that learns the adapted maximum engine speed, calculates the engine speed setpoint by scaling the adapted maximum engine speed relative to the operator demand, predicts the position of the throttle valve, and determines the feed forward signal that will move the throttle valve to the predicted position.

A shovel includes an internal combustion engine, a hydraulic pump connected to the internal-combustion engine, a generator connected to the internal-combustion engine, and a control part that controls the generator. The control part increases an electric generation load of the generator before a hydraulic load of the hydraulic pump increases.