Caterpillar Inc.

Shin Caterpillar Mistubishi Ltd

Rick D Vance

Steven T Ufheil

Marvin K Palmer

Eric Hughes

Stephen J Morey

Nathan T Schenkel

Benjamin Yoo

Peter R Hildner

A method for calibrating a valve having a valve element movable between a flow blocking position and a flow passing position includes pressurizing fluid directed to the valve, increasing a current directed to the valve for controlling a position of the valve element, and sensing a pressure of the fluid. The method for calibrating the valve also includes determining if a time-derivative of the sensed fluid pressure is greater than a predetermined threshold over a predetermined period of time, and determining a cracking point current command directed to the valve. The cracking point current command is directed to the valve when the time-derivative of the sensed fluid pressure is greater than the predetermined threshold.

Method for calibrating independent metering valves

In one aspect of the present invention, an apparatus and method for calibrating an electrohydraulic system is disclosed. In accordance with the present invention, a hydraulic valve that is responsive to an electrical valve signal controllably provides hydraulic fluid flow to a hydraulic actuator. A position sensor senses the position of the hydraulic actuator and responsively produces an actuator position signal. A microprocessor based controller receives the actuator position signal and determines when the hydraulic actuator begins movement, and associates the magnitude of the electrical valve signal to a first predetermined joystick position. Thereafter, the microprocessor based controller determines when the hydraulic actuator movement reaches terminal velocity and associates the magnitude of the electrical valve signal to a second predetermined joystick position.

Method and apparatus for calibrating an electrohydraulic system

An apparatus is provided for use in a vehicle having an engine driven transmission which includes a plurality of gear ratios. The apparatus includes a sensor adapted to sense an operating parameter and responsively produce a parameter signal. A memory device includes a custom shiftpoint map for storing data which relates transmission gear ratio to the parameter signal. A programming device for allowing the custom shiftpoint map to be reprogrammed during vehicle operation. A controller is adapted to receive the vehicle speed signal, retrieve data from the custom shiftpoint map, and process the retrieved data and the parameter signal to produce a transmission control signal. An actuator is adapted to receive the transmission control signal and responsively control the transmission gear ratio.

Automatic transmission with programmable shiftpoints

A horsepower limiting engine control limits the maximum engine horsepower output during operating conditions that might result in torque outputs that are greater than the transmission component ratings. The control includes an electronic controller connected to solenoid driver circuitry, an engine speed sensor and a gear selector. The solenoid driver circuitry energizes a solenoid in response to an engine speed less than a first predetermined engine speed value. The solenoid causes a moveable stop to retract permitting the engine to produce full rated power. The electronic controller causes the solenoid circuitry to de-energize and extend the moveable stop in response to the engine speed exceeding a second predetermined engine speed value and the gear selector being in a predetermined position.

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Washington, IL, United States of America

Rick D Vance