Caterpillar Inc.

Michael Angel Cobo

Douglas W Koehler

Hans P Dietz

Cynthia M Gardner

John James Krone

William Norbert O'Neill

Javad Hosseini

Eric Alan Reiners

Noel J Rytter

Yun-Ren Ho

Richard George Ingram

Bradford Jay Holt

Brett J Janson

Robert E Stone

James E Schimpf

Mark A Robinson

Scott Marks

John D Duffy

James Thomas Ferrier

Justin Ayers

Joshua Mason

Beau James Berning

Andrew G Verheyen

Matthew F Vande Wiele

A work machine may include a steering system, a user interface, a detection device, and a control device. The user interface may generate an input signal corresponding to operator input. The detection device may generate a detection signal corresponding to a presence of an operator relative to the user interface. The control device may determine that the operator is unavailable based on the detection signal and the input signal, and enable a lockout mode based on determining that the operator is unavailable. The control device may determine, while the lockout mode is enabled, a readiness indicator. The readiness indicator may confirm a readiness of the operator based on determining that the detection signal satisfies a readiness criterion. The control device may disable the lockout mode based on determining that the readiness criterion is satisfied.

Operator detection system

A power train for a machine is provided having a power source and a transmission, which includes a plurality of gears configured to produce multiple output ratios when selectively engaged. The power train also has a torque converter operatively coupling the power source and the transmission. A lockup clutch is associated with the torque converter, and the engagement of the lockup clutch is restricted so that the lockup clutch is engaged only when permissible gear ratios are actuated. The power train further has a controller in communication with the lockup clutch, the controller being configured to selectively engage the lockup clutch in either a first or a second shift mode with the number of permissible gear ratios being greater in the first shift mode than the second shift mode.

Automatic transmission with part-throttle shifting

A hydraulic control system having a pump for delivering fluid under pressure from a fluid reservoir, a hydraulic actuator selectively driven by the fluid, the system comprises a main flow control valve connected between the pump and the actuator for selectively providing the fluid to and from the actuator, and a control unit connected to the main flow control valve for controlling operation of the main flow control valve to control the rate of change of the area of the main flow control valve relative to the delivery of fluid from the pump, and the control unit connected to the pump to increase or decrease the actual pump command proportional to the inverse of the pump command.

Hydraulic control system for improving pump response and dynamic matching of pump and valve

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.

Method and apparatus for controlling the deadband of a fluid system

The present invention provides a method and apparatus for controlling the fluid flow in a fluid circuit,. The fluid circuit,includes a pump,driven by an engine,. The pump,delivers fluid to at least one actuator,through a control valve assembly,. In addition, the pump is connected to a bypass control valve, which is connected to a fluid tank. The method includes the steps of establishing a desired fluid flow to be delivered by the pump, determining an expected fluid flow to be delivered by the pump in response to the desired fluid flow, and determining a position of the bypass control valve in response to the expected fluid flow.

Method and apparatus for controlling a bypass valve of a fluid circuit

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.

Method and apparatus for controlling an implement of a work machine

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.

A positive flow control system is provided that uses open-centered control valves in a series connection to provide priority between different fluid circuits and to provide requested flow regardless of the load pressure while minimizing unused or wasted flow. This is accomplished by providing a restriction in the last open-centered control valve to controllably restrict the flow therethrough when the valve is in its neutral position and having the source of pressurized fluid at a minimum displacement position that substantially matches the rate of flow across the restriction. A controller controls the displacement of the source of pressurized fluid and the displacement of the respective open-centered control valves in proportional to the respective input commands. Initial movement of the last open-centered control valve closes off the restricted flow thereacross to the reservoir prior to the source of pressurized fluid being communicated to the associated actuator. The subject system provides priority control and an effective control of wasted fluid while providing the needed flow rate regardless of the load without needing a special control arrangement for priority or separate bypass valve to control wasted flow.

Positive flow control system

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, which is indicative of a desired velocity. A velocity sensor senses the velocity of the lift cylinder and tilt cylinders and responsively producing respective cylinder velocity signals. A microprocessor receives the cylinder velocity and operator command signals, determines the difference between the actual and desired cylinder velocity, and responsively produces an electrical valve signal in response to the velocity difference. 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 value signal.

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.

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Saint Charles, IL, United States of America

Michael Angel Cobo