Caterpillar Inc.

Mark R Hawkins

Joel L Peterson

Lee R DenBraber

Steven J Zmuda

Craig L Koehrsen

Carl A Kemner

Gregory L Williamson

William James Tate

David R Meinhold

John D Duffy

Kenneth Edward Poppe

Dean J Schlickbernd

Ronald J Penick

Bobby D Griffith

Jeffrey L Finley

Steve J Zmuda

A method and apparatus for preventing underdigging of a work machine, which may occur if the implement digs under or too close to the work machine, is disclosed. An underdigging boundary or a space of allowable implement movement is established relative to the work machine. The position of the implement is sensed, and the movement of the implement is controllably prevented from underdigging the work machine.

Apparatus and method for preventing underdigging of a work machine

A method and apparatus for controllably preventing an implement from damaging a work machine or itself, which may occur if the implement strikes the work machine, by restricting the movement of the implement. A boundary is established a predetermined distance from the work machine. By controllably restricting the movement of the implement when it approaches the boundary, the implement is prevented from making contact with the work machine.

Apparatus and method for restricting implement movement of a work machine

A system and method for managing access of at least one mobile machine to a load resource having a loading machine including a queue manager adapted to deliver a queue position request signal, a resource manager adapted to control access to the load resource, and a load manager adapted to determine a load point for a mobile machine.

System and method for managing access to a load resource having a

The invention is a system and method for managing a resource having multiple entry points. Each mobile machine includes a queue manager for generating a queue position request upon approach to the resource. A resource manager establishes queues, one for each entry point to the resource, to control access to the resource. Upon receiving a queue position request from an approaching mobile machine, the resource manager determines which queue to place the mobile machine, and then generates a queue position and sends a queue position signal to the approaching mobile machine.

System and method for managing access of a fleet of mobile machines to a

A control system for lubricating a work machine is provided. The control system includes a lubricant distribution system, a charging system adapted to drive the lubricant distribution system, a sensor for determining the operating state of the charging system, and a device for calculating a time interval being dependent upon a previous lubricating event. The control also includes a device for producing a lubrication signal in response to the time interval reaching a predetermined interval constant.

Lubrication control system for a work machine

A cold fluid protection circuit is provided for controlling the rate of fluid flow in a hydraulic system in response to the temperature of the oil in a reservoir. The subject invention includes a temperature sensor operative to sense the temperature of the fluid in the reservoir and deliver an electrical signal representative thereof to a controller. The controller processes the sensed temperature with respect to the rate of flow in the hydraulic system that is returning to the reservoir from an actuator through a fluid conditioning mechanism and proportionally reduces the rate of flow therethrough by controllably reducing the displacement of a directional valve mechanism in response to the sensed temperature.

Cold oil protection circuit for a hydraulic system

A steering control system for an autonomous machine has a manual steering control valve for directing fluid from a pump to either a head end chamber or a rod end chamber of a hydraulic steering actuator. In one embodiment, an electrically actuated steering valve device is disposed in series flow relationship between the pump and the manual steering control valve and is operative to direct fluid from the pump to the head end and rod end chambers. In another embodiment, a electrically actuated device mechanically actuates the manual steering control valve for steering the machine.

Steering control system for an autonomous machine

A system for controlling autonomous operation of a vehicle in response to speed and steering angle request signals from a navigator allows manual operation of the vehicle. The system includes a machine control module, an engine control module, and a transmission control module. An auto/manual select signal indicates to the machine control module whether operation should be in a fully autonomous mode or a manual mode. In the autonomous mode, a navigator produces a speed request signal and a steering angle request signal for the vehicle. The machine control module receives the speed and steering angle request signals from the navigator. From these inputs, the machine control module produces an engine RPM (revolutions per minute) control signal for the engine control module, a transmission control signal for the transmission control module, a brake control signal, and a steering angle control signal. In the manual mode, the machine control module will not interfere with normal, manual (i.e., manned) control of all vehicle systems.

System for controlling a vehicle to selectively allow operation in

The present invention provides a general purpose driver circuit. The driver circuit is connected to a load. The driver circuit includes a controller for producing a control signal indicative of a desired output current. The driver circuit generates an output current having a magnitude responsive to the magnitude of the control signal. The driver circuit produces a system voltage feedback signal and an output voltage feedback signal and responsively performs output load condition diagnostics.

Driver circuit with diagnostics and over voltage protection

An appparatus for receiving signals from any of a plurality of sensor types is provided and includes pull-up circuitry connected to a circuit input; data edge conditioning circuitry having a digital output and an input connected to said circuit input; and an analog output connected to said circuit input and said pull-up circuitry.

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Chillicothe, IL, United States of America

Mark R Hawkins