Abstract: A hydraulic system for a machine is provided including a first cylinder, a pump and an operator input device for entering a commanded rate of flow of hydraulic fluid to the first cylinder. A control valve operatively is connected between the pump and the first cylinder. A sensor is configured and arranged to provide signals relating to a first operating characteristic of the machine. A controller is in communication with the operator input device, the control valve and the sensor. The controller is configured to determine a skill level of an operator of the machine based on a comparison of the first operating characteristic of the machine and a first threshold and to direct the control valve to provide hydraulic fluid to the first cylinder at an adjusted hydraulic fluid flow rate if the skill level of the operator is below a predetermined level.

Abstract: A hydraulic system for a machine is provided including a first cylinder, a pump and an operator input device for entering a commanded rate of flow of hydraulic fluid to the first cylinder. A control valve operatively is connected between the pump and the first cylinder. A sensor is configured and arranged to provide signals relating to a first operating characteristic of the machine. A controller is in communication with the operator input device, the control valve and the sensor. The controller is configured to determine a skill level of an operator of the machine based on a comparison of the first operating characteristic of the machine and a first threshold and to direct the control valve to provide hydraulic fluid to the first cylinder at an adjusted hydraulic fluid flow rate if the skill level of the operator is below a predetermined level.

Abstract: Individual cylinder output deviations from a normal operating engine cylinder are detected via an analysis of crank shaft speed fluctuations. In the detection phase, the engine is operated at a steady state low idle condition, and engine speed data is collected over a plurality of engine cycles. This data is then averaged, filtered and compared to expected engine speed data. A substantial deviation from the expected speed data in the region of crank shaft angles associated with an individual cylinder during its power stroke adjacent its top dead center position indicates a power level deviation in that cylinder. The magnitude of the power level deviation can then be assessed through a similar procedure where engine speed data is collected, averaged, filtered and compared to expected engine speed data when the engine is operating in a steady state rated condition.

Abstract: A method for determining a condition of a cylinder in an internal combustion engine having a plurality of cylinders. The method includes the steps of reducing an amount of power being generated by a first cylinder, increasing an amount of power being generated by each of the remaining cylinders, monitoring a condition of the engine, and determining the condition of the first cylinder in response to the monitored condition of the engine.

Abstract: A method for determining a condition of a cylinder in an internal combustion engine having a plurality of cylinders. The method includes the steps of reducing an amount of power being generated by a first cylinder, increasing an amount of power being generated by each of the remaining cylinders, monitoring a condition of the engine, and determining the condition of the first cylinder in response to the monitored condition of the engine.

Abstract: A controllable mechanical brake release system for controllably releasing a mechanical brake included in a hydrostatic machine is disclosed. In the preferred embodiment the hydrostatic machine is located on an incline. The mechanical brake is included in a mechanical braking system. The hydrostatic machine has the braking system, a hydrostatic propulsion system and a controller. A determined hydraulic pressure associated with the hydrostatic propulsion system is compared with an established trip indicator. A release mechanical brake signal is produced in response to the comparison.

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: 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: An apparatus for controlling the load of an engine associated with a hydrostatic drive system is disclosed. The apparatus includes a variable displacement pump rotatably driven by the engine. The apparatus modifies a pump displacement command signal in response to the actual and desired engine speed acceleration. The modified pump displacement command signal is used to control the displacement of a variable pump in order to regulate the load on the engine to achieve optimum efficiency.

Abstract: An apparatus is disclosed for controlling the propulsion and steering of a machine. The machine includes a hydrostatic system that drives a pair of ground engaging traction devices. An electronic controller receives operator signals indicative of a desired travel speed and direction, and determines a desired rotational speed of the ground engaging traction devices. The electronic controller produces command signals indicative of the determined speeds to regulate the speed of the ground engaging traction devices to the desired speed.

Abstract: A control device for operating a machine is disclosed. The control device includes a joystick having a central axis and being universally moveable along a first and second axis in a plane perpendicular to the central axis, and a rotatable operator control station that houses the joystick. A joystick position sensor senses the position of the joystick and responsively generates a set of operator command signals corresponding to the displacement and direction of the joystick from the central axis in the first and second axis. A operator station position sensor senses the rotational position of the operator station and responsively generates a position signal. A controller receives the operator command and position signals, and responsively transposes the function of the joystick axis to correspond to the orientation of the machine.

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: An apparatus for controlling the load of an engine associated with an hydrostatic drive system is disclosed. The apparatus modifies a pump displacement command signal in response to the actual and desired engine acceleration. The modified pump displacement command signal is used to control the displacement of a variable pump in order to regulate the load on the engine to achieve optimum efficiency.

Abstract: An apparatus for controlling a material feed system of a paver is disclosed. The material feed system includes a feeder conveyor and a spreader auger. The apparatus includes a sensor that monitors the amount of material at the edge of the screed and responsively produces an actual material height signal. A rotary switch produces a desired material height signal indicative of a desired amount of material at the edge of the screed. A controller receives the actual and desired material height signals, determines a desired rotational speed of the auger in response to the difference between the signal magnitudes, and produces a command signal to rotate the auger at the desired speed. An electrohydraulic system receives the command signal and rotates the auger at the desired rotational speed.

Abstract: In one aspect of the present invention, a control system for a floating screed assembly for an asphalt paving machine is disclosed. The screed assembly includes a main screed and extension screed unit. An electrohydraulic device extends and retracts, as well as, raises and lowers the extension screed unit relative to the main screed unit. The electrohydraulic device additionally pivots the extension screed unit relative to the main screed unit about a horizontal axis. Position sensors produce position signals in response to the position of the extension screed unit. A controller receives the position signals and produces command signals to control the extending, retracting, and pivoting of the extension screed unit to a desired position.

Abstract: A driver circuit for first and second coils includes first and second selector switches coupled in series between first terminals of the coils and a first common junction, first and second diodes coupled in series between second terminals of the first and second coils, respectively, and a second common junction and a source of first potential coupled to the first common junction. A modulation switch is coupled between the second common junction and a source of second potential. The selector switches and modulation switches are operated to cause currents of controlled magnitude to flow through the coils. The circuit has improved fault immunity whereby at least one coil can be energized even when another coil has been subjected to a chassis ground fault.

Abstract: An apparatus is disclosed for controlling the propulsion and steering of a machine. The machine includes a hydrostatic system that drives a pair of ground engaging traction devices. An electronic controller receives operator signals indicative of a desired travel speed and direction, and determines a desired rotational speed of the ground engaging traction devices. The electronic controller produces command signals indicative of the determined speeds to regulate the speed of the ground engaging traction devices to the desired speed.