Caterpillar Inc.

Caterpillar Global Mining LLC

Sean Johnson

Sharath Cugati

Pengfei Ma

Jiao Zhang

Stephen V Lunzman

Brett J Janson

Christopher Alan Williamson

Mark Vonderwell

John Andrew Yeoman

James William Fuerst

Michael P Chiaramonte

Marcus Bitter

Justin Ayers

Robert Stone

Christoper Williamson

Bryan L Fredrickson

A closed-loop hydraulic circuit associated with a swing mechanism of a machine is controlled to obtain both a pressure control during acceleration and deceleration of the swing mechanism and a velocity control during coasting. In this manner, a system pressure in closed-loop hydraulic circuit is maintained below a maximum allowable pressure during acceleration and deceleration, and the swing mechanism can be rotated at a desired constant speed during coasting. This is achieved by controlling a hydraulic actuator adjusting the displacement of a variable displacement pump in different control modes, depending on a comparison between a desired displacement of the pump and an actual displacement of the same.

Hydraulic control system and method

A hydraulic system for a machine includes a plurality of hydraulic component, wherein the hydraulic components include hydraulic actuators and hydraulic motors. The hydraulic system also includes a plurality of hydraulic circuits, and a plurality of hydraulic pumps for supplying hydraulic fluid to the plurality of hydraulic components via the hydraulic circuits. At least one hydraulic component receives hydraulic flow exclusively from a designated one of the hydraulic pumps and at least another, different hydraulic component receives shared hydraulic flow from a flow sharing set of the hydraulic pumps.

System and method for providing hydraulic power

A hydraulic circuit for controlling a component of a hydraulic machine includes an actuator having a head end chamber and a rod end chamber, the actuator having an extended position for moving the component in a first direction and a retracted position for moving the component in a second direction. The hydraulic circuit includes a regeneration valve having an open position for fluidly connecting the head end chamber to the rod end chamber, a first control valve having a first open position, a second open position for fluidly connecting the regeneration valve to the return tank and substantially fluidly disconnecting the rod end chamber from the fluid source, and a closed position, and a second control valve having a first open position, a second open position, and a closed position for substantially fluidly disconnecting the rod end chamber from the fluid source.

Hydraulic control circuit with regeneration valve

A method is provided for controlling an all-wheel-drive vehicle. The method includes providing an aggression signal and determining a desired speed ratio based on the aggression signal. An output speed signal corresponding to the determined desired speed ratio is generated.

Control for an all-wheel-drive vehicle

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Ratingen, Germany

Sean Johnson