Abstract: A control system for controlling an internal combustion engine is disclosed. The control system employs closed loop engine speed control and includes a primary and secondary engine speed sensor. An electronic control module detects a failure of the primary or secondary sensor and causes the other sensor to be used as the engine speed feedback signal in the closed loop control.

Abstract: An electronic engine control is disclosed having an electronic cooling fan control. The cooling fan is turned on or off according to a predetermined strategy and inputs from several engine parameter sensors. By disengaging the cooling fan when it is not needed for engine cooling, the fan control reduces the power that is unnecessarily drawn from the engine to drive the fan.

Abstract: Machine assemblies often include driving and driven members such an engine associated with a driven load. These members typically include rotatable shafts (16, 18) interconnected by a flexible coupling element (20). System torsionals in such a machine often cause the shafts (16, 18) to be out of phase with one another. When this occurs, excessive energy is transferred to the coupling element (20). The subject apparatus (22) includes a device (24) for detecting and measuring rotational phase differences between driving and driven rotatable shafts (16, 18). The measured phase differences are compared with a reference phase difference level and an error signal is produced in response to the measured phase difference exceeding the reference level.

Abstract: An apparatus is provided for use in a vehicle having a source of pressurized fluid and a pair of hydraulic drive motors connected to the pressurized fluid source and powered thereby. First and second ground engaging devices are connected to and driven by the first and second motors, respectively. The apparatus includes first and second control members, each being positionable at a plurality of locations for indicating a desired speed and direction for a respective drive motor. First and second actuators are adapted to sense the position of the first and second control members, respectively, and responsively control the direction and rate of fluid flow to the first and second drive motors. A set switch is movable between first and second positions and is adapted to produce a set speed signal in the second position.

Abstract: The present invention provides a control which automatically elevates engine speed to a preselected value when the vehicle coasting in neutral above a preselected speed. In order to accomplish this objective, the engine controller is adapted to receive an actual gear ratio signal and a vehicle speed signal, If the vehicle is in neutral and engine speed is above a preselected threshold, the controller sets the desired engine speed to a preselected value which has been empirically determined to ensure sufficient transmission cooling and lubrication, Controlling to this speed also reduces transmission wear when the transmission is reengaged at high ground speeds.

Abstract: An apparatus (8) is provided for controlling ignition in an engine having a ignition system (10), an engine cylinder sensor (48), and a piston disposed in the cylinder and being movable to a top dead center (TDC) position. The cylinder sensor (48) produces a first signal representing the position of the piston within the cylinder and having a frequency responsive to engine speed. The ignition system (10) includes a transformer (24) having a primary coil (26) which is energized in response to a cylinder select signal to produce sparking across an associated spark plug gap (22). A first circuit (98) is provided for sensing a delay between production of the cylinder select signal and the time at which current through a respective primary coil exceeds a preselected current level, and responsively producing a timing error signal.

Abstract: An implement control system is provided for controllably raising and lowering an implement relative to a work vehicle. The implement is pivotally connected to the work vehicle and movable between maximum raised and lowered positions in response to the extension and retraction of a hydraulic cylinder. The implement control system is operative for controllably connecting the hydraulic cylinder to a hydraulic accumulator as the implement reaches its desired position, thereby slowing movement of the implement in a smooth manner.

Abstract: A control system is provided for a vehicle regulating engine speed during shifts so as to reduce driveline torque and shift shock. The control system includes separate microprocessor based engine and transmission controllers which communicate via a data link. When a shift is initiated, the transmission controller delays a period of time sufficient for the transmission to disengage the old gear ratio and then produces a CTSSPEED signal. The transmission controller continues to produce the CTSSPEED signal for a second period of time which corresponds to the time required for the transmission to engage the new gear ratio.The engine controller receives the desired engine speed signal and regulates engine speed into correspondence with the desired speed. During upshifts, the CTSSPEED signal is set to a speed which is a predetermined amount above the synchronization speed of the new gear for an upshift.

Abstract: In accordance with one aspect of the present invention, an apparatus is provided for a vehicle equipped with a drive system and a controller for regulating the operating speed of the drive system. The apparatus includes at least one sensor for sensing a vehicle parameter and producing a parameter signal in response to the sensed parameter. A diagnostic device is provided for receiving the parameter signal, processing the parameter signal to detect the presence of an undesirable operating condition; determining the severity of the undesirable operating condition in accordance with a preselected strategy and responsively producing a severity level signal. The controller receives the severity level signal and limits the maximum speed of the vehicle in response to the severity level signal, whereby the maximum allowable vehicle speed decreases as the severity level signal increases.

Abstract: An apparatus is provided for use in a vehicle having an engine driven transmission which includes a plurality of gear ratios. The apparatus includes a sensor adapted to sense a parameter indicative of vehicle speed and responsively produce a vehicle speed signal. A downshift switch is provided to controllably produce a downshift signal. An engine speed sensor senses engine speed and responsively produces an engine speed signal. A controller is adapted to receive the vehicle speed, engine speed, and downshift signals, process the vehicle speed signal to produce a transmission control signal, produce a down shift enable value as a function of the engine speed signal, and modify the transmission control signal to correspond to a lower gear ratio in all but the lowest gear ratio when the downshift signal is received and a value responsive to the vehicle speed signal is less than the down shift enable value signal.

Abstract: A control system is provided for use with a hydraulic system which includes a source of pressurized fluid, a plurality of flow regulator means, and a plurality of fluidly powered components. Each flow regulator means is adapted to receive the pressurized fluid and is responsive to a respective control signal for regulating the flow of pressurized fluid to respective fluidly powered components. The control system includes a plurality of control members, each being movable to a plurality of locations for indicating a desired fluid output for a respective flow regulator means. A plurality of sensors are provided for sensing the position of respective control members and responsively producing respective position signals. A primary controller is adapted to receive the position signals, process the received signals to responsively produce the control signals, and deliver the control signals to the flow regulator means.

Abstract: A method is provided for executing a subroutine in a computer which includes a memory and a stack. The memory has a plurality of sequentially ordered memory address locations referenced by respective address codes. The subroutine is stored in a preselected range of memory locations. The method includes storing a signature word on the stack, the signature word corresponding to an entry address code in memory for the subroutine; storing a return address on the stack, the return address code corresponding to a memory location where control is to be passed after execution of the subroutine; passing control to the subroutine entry address; executing the subroutine; comparing the signature word stored on the stack with the subroutine entry address code; passing control to the return address if the compared values are equal; and executing a software interrupt if the compared values are not equal.

Abstract: A drive system for a work vehicle is provided which includes first and second hydrostatic transmissions which are responsive to respective control signals for driving first and second ground engaging devices at a rate responsive thereto. A sensor is provided sensing the position of a manually operable control element and responsively producing a desired speed signal. A memory device is adapted to store data relates the desired speed signal to the first and second control signals in a preselected manner. A processor is provided for receiving the desired speed signal, responsively retrieving at least a portion of the data from the memory device, and producing the first and second control signals in response to the retrieved data and the desired speed signal. An adjusting device is provided for receiving at least one of the control signals, permitting controllable adjustment of the control signal so as to vary the speed of a respective ground engaging device.

Abstract: An apparatus is provided for operating an internal combustion engine having an inlet air filter and a plurality of solenoid operated fuel injection units adapted to receive fuel injection signals and responsively inject fuel into associated engine cylinders. The apparatus includes a sensor adapted to sense a level of clogging of the air filter and responsively produce a clogging level signal. An electronic controller is adapted to produce the fuel injection signals as a function of sensed operating parameters and in accordance with a preselected horsepower curve. The controller is further adapted to receive the clogging level signal, compare the clogging level signal to a preselected threshold and limit the maximum engine horsepower in response to the clogging level signal being equal to or greater than the preselected threshold.