Abstract: An apparatus for controllably positioning a work implement of an earth moving machine is disclosed. The work implement includes a boom and an attachment being attached thereto where the boom is actuated by a hydraulic lift cylinder and the attachment is actuated by a hydraulic tilt cylinder. Implement position sensors sense the elevational position of the boom and the pivotal position of the attachment and responsively produce respective implement position signals. A controller that receives the implement position signals, compares the relative position of the boom and the attachment with a pre-determined boundary condition, and produces an electrical valve signal. A valve assembly receives the electrical valve signal and controllably provides hydraulic fluid flow to the respective hydraulic cylinders in response to a magnitude of the electrical valve signal.

Abstract: The present fluid cylinder includes a cylinder body having a cylindrical internal cavity therein with a longitudinal axis therethrough, the internal cavity being adapted for disposition of a piston and rod assembly for axial movement therein. The cylinder includes a member such as an end cap enclosing an axial end of the internal cavity, the member having a sensor port or passage therethrough extending between an internal opening communicating with the internal cavity and an external opening. A sensor is disposed in the internal opening of the sensor port or passage, and a sensor electronics module is disposed therein between the sensor and the external opening. The sensor is operable for sensing an axial distance of the piston or the rod from a predetermined location when disposed in the internal cavity and outputting signals representative of the distance to the sensor electronics module which includes circuitry for retrieving the signals.

Abstract: A method and apparatus for controlling the speed of an engine having a plurality of cylinders and a compression brake operable on one or more of the cylinders is disclosed. The method includes determining a speed of the engine, comparing the engine speed to a first threshold, and activating the compression brake for at least one of the cylinders in response to the engine speed exceeding the first threshold.

Abstract: The present fluid cylinder includes a cylinder body having a cylindrical internal cavity therein with a longitudinal axis therethrough, the internal cavity being adapted for disposition of a piston and rod assembly for axial movement therein. The cylinder includes a member such as an end cap enclosing an axial end of the internal cavity, the member having a sensor port or passage therethrough extending between an internal opening communicating with the internal cavity and an external opening. A sensor is disposed in the internal opening of the sensor port or passage, and a sensor electronics module is disposed therein between the sensor and the external opening. The sensor is operable for sensing an axial distance of the piston or the rod from a predetermined location when disposed in the internal cavity and outputting signals representative of the distance to the sensor electronics module which includes circuitry for retrieving the signals.

Abstract: The present invention provides a method and apparatus for controlling a fluid system. The fluid system includes a hydraulic circuit having a pump driven by an engine. The pump delivers fluid to an actuator through a valve assembly. The method includes the steps of receiving an operator input, determining a condition of the hydraulic circuit, determining a valve command in response to the circuit condition and the operator input, and delivering the valve command to the valve assembly.

Abstract: An apparatus for controlling the torque associated with a power train of a machine having a work implement is disclosed. A plurality of position sensors sense the position associated with the work implement and responsively produce respective position signals. A controller modifies the desired engine speed in response to the angular position of the work implement and regulates the speed of the engine at the modified desired engine speed to control the power train torque.

Abstract: An apparatus for controllably moving a work implement of an earth moving machine is disclosed. The work implement includes a boom and a bucket being attached thereto where the boom is actuated by a hydraulic lift cylinder and the bucket is actuated by a hydraulic tilt cylinder. An operator controlled joystick produces an operator command signal for controlling the movement of the work implement. Implement position sensors sense the elevational position of the boom and the pivotal position of the bucket, and responsively produce respective implement position signals. A controller receives the implement position and operator command signals, determines the instant position of the work implement, reduces the operator command signal as the boom is being raised and the bucket is being pivoted, and produces an electrical valve signal based on the reduced operator command signal.

Abstract: A method for controlling the displacement of a variable displacement hydraulic pump to produce a desired flow of fluid is disclosed. The method includes the steps of: determining that the machine is being operated in a digging cycle; determining a desired displacement of the pump, the desired pump displacement being less than the maximum pump displacement; and controlling the pump displacement to the desired pump displacement to produce a desired flow of fluid.

Abstract: An apparatus and method for providing an automated back-up alarm on a mobile machine including a back-up detector to detect enablement of rearward motion by the mobile machine, a visual indicator, an audible indicator, and a controller. The apparatus detects enablement of rearward motion by the mobile machine and a parameter representative of ambient light, and responsively activates one of the visual indicator and the audible indicator as a function of the mobile machine being enabled to move in a rearward direction and the parameter representative of ambient light.

Abstract: A track belt tensioning management system is provided for actively adjusting the tension on a track belt in response to the difference in linear output speed between a drive wheel and the track belt. This is accomplished by sensing the speeds of the drive wheel and the track belt and delivering the sensed signals to a controller which processes the signals and determines the difference in their respective linear output speeds. If the difference varies from a predetermined value, the controller directs appropriate signals to a hydraulic valve arrangement which controllably directs pressurized fluid to and from a hydraulic actuator arrangement to adjust the tension between the drive wheel and the track belt. The subject arrangement maintains sufficient frictional force between the drive wheel and the belt to control the slip therebetween as required while at the same time limiting the forces in order to reduce premature failures and/or wear on the track belt and other associated components.

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: Apparatus and method for controlling at least one hydraulic cylinder by the hydraulic fluid discharged by a hydraulic pump through a control valve. The hydraulic control system includes sensors to sense the conditions of the system and produce responsive signals. In the first stage, a controller determines an initial pump displacement output value and an initial spool displacement output value as a function of the system condition signals according to a plurality of feedback linearization control laws. In the second stage, a second controller produces an output signal for the hydraulic pump and an output signal for the control valve as a function of the initial pump displacement output value, the initial spool displacement value and an input command signal according to linear control laws.

Abstract: The present invention provides a sensing system and method for providing information relating to a drivetrain during shifting operations. The drivetrain includes an engine, a torque converter and a transmission. The system includes sensors for detecting the output speed of the engine, the output speed of the torque converter, and the output speed of the transmission. The system detects the starting condition of a shifting operation, responsively determines a set of performance parameters, and produces a set of performance parameter signals.