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(11) | EP 2 065 624 A8 |
(12) | CORRECTED EUROPEAN PATENT APPLICATION |
Note: Bibliography reflects the latest situation |
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(54) | A method of driving an hydraulic actuator by means of a pressure-controlled proportioning solenoid valve |
(57) A method of driving a hydraulic actuator (13) provided with a pressure-controlled
proportioning solenoid valve (21); the method includes the steps of: determining a
first open-loop contribution (Ip) according to a pressurized oil flow rate (QFF) which crosses the proportioning solenoid valve (21) and according to the desired
load pressure (Pload) inside the actuation chamber (20); determining a second open-loop contribution (IQFF) according to the desired position (XSpoolRef) of the spool (29) of the proportioning solenoid valve (21); determining a third
closed-loop contribution (IQCL) according to the difference (εX) between a desired value (XREF) of the position of the mobile piston (22) and a real value (X) of the position of
the mobile piston (22); and calculating a desired electric driving current value (ITOT) of the proportioning solenoid valve (21) by means of an algebraic sum of the three
contributions (IP, IQFF, IQCL).
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