Robert Boschgmbh

Georg Schoppel

Torsten Bertram

Roland Gerhart

Ingo Glowatzky

Werner Zeh

Christoph Krimpmann

Alexander Kroeper

Wolfgang Volpert

Steffen Fischer

Daniel Barriga

A hydraulic spool valve includes a valve housing which has a valve bore having two control chambers, which directly follow one after the other axially at a distance and extend beyond the diameter of the valve bore. A connection surface of the valve housing has a pump connection opening connected by a first fluid channel to a first of the two control chambers. A consumer connection opening is connected by means of a second fluid channel to a second of the two control chambers. The valve has a control piston, which is guided back and forth in the valve bore to fluidically connect or separate the two control chambers. A radial web of the valve housing projects into each control chamber, with an extension delimited in the circumferential direction. The web in the second control chamber is longer in the circumferential direction than the web in the first control chamber.

Hydraulic spool valve

The disclosure relates to a method for determining a switching function for a sliding mode controller for controlling a controlled variable of a system, the switching function being selected as a function of a control deviation of the controlled variable and its time derivatives up to at least the second order and on the basis of initial control dynamics of the system, coefficients of the switching function being represented by means of poles of a closed control loop of the system, the poles each being selected as a function of the control deviation, and desired control dynamics of the system being set by shifting at least one first pole of the poles, and to such a sliding mode controller and to a use of such a controller.

Method for determining a switching function for a sliding mode controller, and sliding mode controller

An electrohydraulic pressure control arrangement comprises a proportional pressure valve and a control loop structure. The control loop structure has a control path through which an actuating variable is fed to an actuating input of the proportional pressure valve starting from a setpoint pressure value. A pressure sensor detects an actual pressure value at a connection of the proportional pressure valve. A system model of a pressure valve assigns an estimated pressure value to the setpoint pressure value, and a subtraction element determines a control error as the difference between the estimated pressure value and the actual pressure value. A weighting element subjects the control error to a weighting operation and thus determines a weighted control error. The weighting element is designed such that relatively large control errors are attenuated to a greater extent than relatively small control errors.

Electrohydraulic pressure control arrangement and method for pressure control

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Lohr, Germany

Georg Schoppel