Abstract: Systems for monitoring sensed parameters and diagnosing fault conditions are useful in connection with many machines. Advantageously, such systems are capable of indicating the level of the sensed parameters in both a graphical and a digital format. In the subject invention, a switch selects one of a normal mode and a numeric readout mode. A sensor produces a sensor signal. A device displays a number in digital form that is representative of the sensor signal in response to the switch selecting the numeric readout mode. A gauge is provided to display the sensor signal in graphical form in response to the switch selecting the normal mode and to flash an illuminable device in response to the switch selecting the numeric readout mode.

Abstract: A jerk control valve adapted for use in a pilot operated steering system has a pilot operated valve biased to an open position by a spring for communicating left steer and right steer pilot lines to a tank through a pair of orifices. The pilot operated valve is moveable to a closed position blocking communication through the first and second orifices when the highest pressure of the left and right steer pilot lines exceeds a predetermined value. The left and right steer pilot lines are continuously communicated with the tank through a pair of orifice devices.

Abstract: An apparatus for cooling an axle assembly includes a housing defining a chamber having a first fluid contained therein. The apparatus also includes a conduit located within the chamber. The apparatus further includes a fluid source in fluid communication with the conduit, wherein (1) a second fluid located within the fluid source is advanced through the conduit, and (2) the first fluid located within the housing does not intermix with the second fluid being advanced through the conduit. A method of cooling a differential assembly is also disclosed.

Abstract: In one aspect of the present invention, a method for controlling the steering of a directionally steered machine having a hydrostatic system that drives a plurality of driven wheels is provided. The method includes the steps of producing a steering angle signal indicative of the angle of the steered wheels and a wheel speed signal indicative of the rotational speed of the driven wheels, and generating a programmable curve that represents the resulting driven wheel speeds as a function of the angle of the steered wheels. The generated curve is then stored in a software map to be later used to determine the driven wheel speeds based on the angle of the steered wheels.

Abstract: A traction control apparatus for a work machine having an engine and a hydrostatic drive system that powers a first and second set of ground engaging traction devices is disclosed. The hydrostatic drive system includes a variable displacement pump being rotatably driven by the engine, and first and second variable displacement motors which receive pressurized fluid from the variable displacement pump, the first motor driving the first set of ground engaging traction devices and the second motor driving the second set of ground engaging traction devices. The control apparatus includes a first speed sensor that produces a first speed signal indictative of the rotational speed of the first set of ground engaging traction devices and a second speed sensor that produces a second speed signal indictative of the rotational speed of the second set of ground engaging traction devices.

Abstract: A method for monitoring the integrity of an integrated positioning system located on a mobile machine is provided. The integrated positioning system includes a GPS receiver and an inertial navigation unit (INU). The INU includes an odometer, a Doppler radar, a gyroscope, and a sensor for measuring the steering angle of the mobile machine. The method includes the steps of receiving a GPS position estimate from a GPS receiver, receiving an INU position estimate from an inertial navigation unit, and comparing the GPS position estimate and the INU position estimate. If the two position estimates are the same, then the system is VALID. Otherwise, the velocity of the mobile machine as determined by the odometer and velocity as determined by the Doppler radar are compared. If the difference is greater than a first predetermined threshold, then the INU is determined to be INVALID. Otherwise a heading rate from gyroscope is compared with a calculated heading rate based on measured steering angle and velocity.

Abstract: A method and apparatus for controlling an earthworking implement on an earthworking machine to preserve a crown on the surface of a road, including determining the position of the crown on the road surface, choosing a sloped grade on one side of the crown, positioning the earthworking implement on the sloped grade so that a first end of the earthworking implement is on the road surface. The processor determines a desired position of a second end of the earthworking implement so that the second end overlaps the crown and the earthworking implement does not cut the crown.

Abstract: An apparatus for controllably moving a work implement. The implement is connected to a work machine and is moveable in response to the operation of a hydraulic cylinder. The apparatus includes an operator controlled joystick that generates an operator command signal, which is indicative of a desired velocity of the work implement movement. Cylinder position sensors produce cylinder position signals in response to the position of lift and tilt cylinders. A valve assembly receives an electrical valve signal, and controllably provides hydraulic fluid flow to the respective hydraulic cylinders to move the cylinders in accordance with the operator command signal. A controller receives the operator command and cylinder position signals, and responsively produces a pump command signal to change the displacement of a variable displacement pump to regulate the movement of the hydraulic cylinders.

Abstract: A method for determining the relationship between the heading of a machine and the course of machine travel is provided. The method includes the steps of determining a previous and current course of machine travel, and a current and filtered heading. An indicator is used to represent the relationship between the heading of the machine and the course of machine travel. The previous and current course of machine travel are compared and the indicator is responsively updated. The current and filtered heading are compared and the indicator is again responsively updated, and then the filtered heading is updated.

Abstract: In one aspect of the present invention, an automatic screed temperature control is disclosed. The control senses the screed temperature and compares the screed temperature to a lower set point. In response to the screed temperature being less than the lower set point, the control causes fuel to dispense into the combustion chamber and subsequently causes the fuel to ignite in order to heat the screed. The screed is heated until the screed temperature becomes greater than an upper set point.

Abstract: A radio frequency data link that establishes communications between a controller and a remote controllable system is disclosed. The controller includes an interface device that produces command signals indicative of desired system functions. A transmitting RF modem receives the command signals and responsively generates radio frequency signals that are representative of the command signals. A remote controllable system includes a receiving RF modem that receives the radio frequency signals and responsively converts the signals into control signals. A logic device receives the control signals, performs the desired function, and produces a reply signal that indicates the status of the function.

Abstract: A method and apparatus to determine the payload in a mobile machine by measuring the total weight of the mobile machine, the fuel in a fuel tank on the mobile machine, and the payload. The weight of the fuel is determined as the machine operates, and the actual weight of the payload is determined by subtracting the weight of the fuel and the weight of the mobile machine.

Abstract: An apparatus for determining the position of a work implement relative to an earthworking machine. An antenna is mounted to the machine and is oriented to transmit a high frequency signal toward the implement and receive a reflected signal back from the implement. An oscillator is electrically coupled to the antenna and energizes the antenna with electrical energy to generate the high frequency signal. The oscillator produces an output signal having a frequency responsive to the inductance of the antenna. A microprocessor based circuit receives the output signal of the oscillator and responsively determines the position of the work implement relative to the machine. The position of the work implement is a function of the frequency of the output signal.

Abstract: System and method for determining an operating point of a mobile machine. The invention receives GPS information from a GPS and INU information from an inertial navigational unit. A plurality of error states are modeled. The operating point of the mobile machine is determined as a function of the error states and the GPS and INU information.

Abstract: An apparatus for controllably moving a work implement is disclosed. The implement is connected to a work machine and is moveable in response to operation of a hydraulic cylinder. The apparatus includes an operator controlled joystick. A joystick position sensor senses the position of the joystick and responsively generates an operator command signal. Boom and bucket angle sensors sense the position of the work implement and responsively produces an boom angle signal and a bucket angle signal respectively. A microprocessor based controller receives the boom angle, bucket angle, and operator command signals, modifies the operator command signal, and produces an electrical valve signal in response to the modified operator command signal. An electrohydraulic valve receives the electrical valve signal, and controllably provides hydraulic fluid flow to the hydraulic cylinder in response to a magnitude of the electrical valve signal.

Abstract: In one aspect of the present invention, a method for detecting a powerless condition of a reciprocating internal combustion engine is provided. The engine has a plurality of reciprocating components, at least one cylinder and a crankshaft. The method includes the steps of sensing angular velocity of the crankshaft and responsively producing an angular velocity signal and determining a rate of fuel supplied to the one cylinder and responsively producing a fuel rate signal. The method further includes the steps of determining an indicated torque for the one cylinder as a function of the angular velocity signal and the fuel rate signal and responsively producing an indicated torque signal. Further, the method includes the steps of determining a requested torque for the one cylinder as a function of the fuel rate signal and the angular velocity signal and responsively producing a requested torque signal.

Abstract: A traction control system for a machine having two driven wheels is disclosed. Braking mechanisms controllably apply braking forces to each of the driven wheels. Transducers produce an actual speed signal having a value proportional to the rotational velocity of each driven wheel. A microprocessor produces a desired speed signal having a value representative of a desired rotational velocity of each driven wheel, and an error signal representative of the difference between the values of the desired and actual speed signals. The microprocessor additionally multiplies the error signal by a gain value and produces a braking command signal to the braking mechanism to apply braking forces to a slipping wheel. The present invention provides the advantage of modifying the gain value based on machine operating conditions in order to achieve good performance.

Abstract: An apparatus for determining the timing of an internal combustion engine having a crankshaft, a camshaft, and a plurality of cylinders each having an electronically controlled fuel injector is disclosed. A crankshaft sensing device monitors the rotation of the engine crankshaft and responsively produces a crankshaft pulsetrain. Additionally, a camshaft sensing device monitors the rotation of the engine camshaft and responsively produces a camshaft pulsetrain. An engine control receives the crankshaft and camshaft pulsetrains, and responsively determines the period of each pulse, determines the rotational position of the crankshaft and camshaft, and produces an inject signal relative to one of the crankshaft and camshaft pulsetrains to the fuel injector in order to initiate fuel injection.

Abstract: The present invention is directed toward estimating certain operating parameters of an earth moving machine. Advantageously, the present invention utilizes a Kalman filter to estimate the pitch, pitch rate and ground speed of the earth moving machine as a function of the sensed pitch and ground speed signals. By estimating the pitch and ground speed, the present invention overcomes the prior problems of sensing signal noise and bias. The present invention overcomes these problems by combining pitch, pitch rate and ground speed, and determining an estimate of pitch and ground speed by using a sensor measurement model, machine process model and Kalman filter update equations.

Abstract: An anti-spin apparatus for a machine is disclosed. The machine is articulated and has at least one axle set with at least two driven wheels. The anti-spin apparatus includes braking mechanisms which controllably apply braking forces to each of the driven wheels. A controller produces a slip signal having a value responsive to the difference in rotational velocity between the wheels of the axle set. A transducer produces an articulation signal having a value responsive to the angle of articulation of the machine. Further, a microprocessor receives the slip signal and the articulation signal, and produces a braking control signal. One of the braking mechanisms receives the braking control signal and responsively applies the braking forces to the faster rotating wheel.