Abstract: The present invention is adapted to provide a method for dynamically determining optimal governor dynamics, i.e., gains, for a fuel control system supplying fuel to an engine. The method determines a mode of the engine, then determines the governor gain in response to the engine mode. The mode or condition of the engine includes a transmission mode, a throttle mode, and a cruise control mode. The governor gains are determined by determining the current engine mode, selecting the appropriate gain look-up table in response to the engine mode, and responsively selecting a gain value from the look-up table in response to at least one of the desired and actual speed. The gain maps are determined using empirical data and classical control system design methods, and storing the results in gain maps, or tables. The governor gain values are used in a forward and a feedback path PID control algorithm.

Abstract: The present invention is an apparatus for controlling exhaust gas recirculation in an internal combustion engine. The apparatus includes an exhaust gas recirculation controller that uses sensed engine operating parameters and the engine operational mode to determine whether to enable or disable the exhaust gas recirculation valve. When the valve is enabled, a closed-loop controller determines the desired amount of exhaust gas to recirculate and the corresponding position of the exhaust gas recirculation valve to introduce the desired amount of exhaust gas into the engine's air intake manifold. The desired valve position is converted to a current signal which is transmitted to an actuator to move the valve. When the valve is disabled, the current signal is set to a value to close the valve to prevent exhaust gas from being circulated in the engine's air intake manifold.

Abstract: In one aspect of the present invention, a method for determining a fuel command for an engine having a cruise control system is disclosed. The method includes the steps of determining a desired engine speed, determining an actual engine speed, modifying the actual engine speed value in response to a previous value of the engine speed, and then determining the fuel command in response to the modified and desired engine speed.

Abstract: The present invention is an apparatus for controlling the fuel rate to an engine using the throttle position, and for controlling the speed of the engine using decision logic to choose the best alternative among candidate fuel levels. A minimum speed governor determines a minimum fuel level at a predetermined low idle engine speed, a maximum speed governor determines a maximum fuel level at a predetermined high idle engine speed, and at least one fuel rate map is used to determine fuel level based on various engine operating parameters. Each governor outputs a fuel quantity signal based on the difference between the corresponding desired engine speed and the actual engine speed. The fuel rate map may be a multi-dimensional data table that provides fuel quantity signals to optimize engine performance based on the throttle position, engine speed, boost pressure, and other engine operating states.

Abstract: An apparatus and method for determining the current waveform of a fuel injection signal so as to consistently control the amount of fuel injected by an electronically controlled hydraulic actuator unit injector fuel system to an engine is disclosed. The apparatus and method varies the waveform of a fuel injection signal using equations or look-up maps and based on sensed operating parameters, which preferably include a desired speed of the engine or desired fuel quantity to be injected during an injection event, actuating fluid pressure and engine speed.

Abstract: A method for controlling transfer from use of a first injection waveform type to use of a second injection waveform type in a hydraulically-actuated electronically-controlled fuel injection system of an engine includes sensing an engine speed and an engine load when the first injection waveform type is selected and storing the sensed engine speed and the sensed engine load. An actual engine speed is thereafter compared with the stored engine speed and an actual engine load is thereafter compared with the stored engine load. Transfer from use of the first injection waveform type to use of the second injection waveform type is prevented unless at least (i) a difference between the actual engine load and the stored engine load exceeds a predetermined load amount, or (ii) a difference between the actual engine speed and the stored engine speed exceeds a predetermined speed amount.

Abstract: Large work vehicles include hydraulic implement control systems having an hydraulic pump being driven by an internal combustion engine. The subject invention provides a method and apparatus for controlling such an hydraulic system to limit engine lug. The invention includes a sensor for producing a parameter signal indicating the load on the engine and a pump control for varying the displacement of the variable displacement pump in response to engine load increasing above a predefined level. The response of the pump control is restricted to allow the engine to reach a predefined operating state.

Abstract: Large work vehicles include hydraulic implement control systems having an hydraulic pump being driven by an internal combustion engine. The subject invention provides a method and apparatus for controlling such an hydraulic system to control engine lug while the hydraulic system is operating. The apparatus includes one or more sensors for producing parameter signals in response to the level of one or more hydraulic system operating parameters. A control receives the parameter signals and responsively produces a supplemental control signal which is used to control engine lug.

Abstract: The present invention provides an apparatus for controllably actuating a work implement. The work implement includes at least a first linkage and a second linkage. The apparatus produces a control signal, senses the position and velocity of the first and second linkages and responsively produces position and velocity signals. The apparatus responsively produces a command signal as a function of the control signal and the position and velocity signals. The command signal controls actuation of the first linkage such that dynamic coupling between the first and second linkages is minimized.

Abstract: An apparatus for controllably actuating a hydraulic actuator is provided. The apparatus is connected between a source of pressurized hydraulic fluid and the hydraulic actuator. The apparatus controllably provides pressurized hydraulic fluid to the hydraulic actuator. The apparatus includes a controller for receiving an operating signal and a load pressure signal and responsively actuating the hydraulic actuator.

Abstract: An apparatus, is adapted to controllably position a movable element in a hydraulic motor. A controller receives a request signal and velocity and/or position signals from sensors. The controller, in accordance with a control scheme using velocity and/or position feedback, determines the flow of hydraulic fluid to the cylinder needed to reduce velocity and/or position errors. A directional valve, actuated by an electrohydraulic pilot system, delivers hydraulic fluid to the hydraulic motor.

Abstract: An apparatus controls an electrohydraulic system of a work vehicle. The work vehicle has a engine, at least one fluid circuit having a variable displacement pump driven by the engine, and a plurality of control valves for controllably passing fluid from the variable displacement pump to a plurality of respective work elements. A device produces a signal indicative of a desired velocity of a respective work element. A device senses a load on a work element and producing a signal representative of the actual load in response to the sensed load. A control device receives the desired velocity signal and load signals, and responsively calculates a desired power level for the electrohydraulic system. Responsively, the control device produces an engine speed command signal indicative of an optimum engine speed in response to the desired power level.

Abstract: An apparatus is provided for controllably positioning a movable element within a hydraulic motor in response to a flow request signal. An electric circuit receives the flow request signal and responsively produces an energization signal. An electromagnetic actuator has a core, and a coil with a plurality of windings wound as a helix around the core. The coil is adapted to receive the energization signal and responsively produce a magnetic force proportional to the magnitude of the energization signal forcing the core to move bidirectionally relative to the coil. A mechanical coupling has one end connected to and movable with the core. A directional valve includes a spool connected to the other end of the mechanical coupling. The directional valve precisely meters pressurized fluid to the motor causing the movable element to move in response to the movement of the core.