PRESSURE OVERSHOOTING PREVENTION SYSTEM FOR ELECTRONIC HYDRAULIC PUMP IN HYDRAULIC SYSTEM

摘要

The present disclosure relates to a pressure overshooting prevention system for an electronic hydraulic pump in a hydraulic system, in which a flow rate command is added (+), a discharge flow rate is subtracted (−), a displacement flow rate (Delta Q) is calculated, a first pressure command corresponding to the displacement flow rate (Delta Q) is generated, a working fluid pressure value corresponding to the discharge flow rate is generated, a limit pressure command is generated to limit an increasing gradient of the working fluid pressure value, a stall is determined based on a first rate of change of the flow rate command, and a second rate of change of the discharge flow rate, and the limit pressure command is set to a second pressure command when the stall is determined, and a small value of the first pressure command and the second pressure command is selected as a final pressure command so as to control an electronic proportional control valve, thereby reducing overshooting of the electronic hydraulic pump.

主权项

1. A pressure overshooting prevention system for an electronic hydraulic pump in a hydraulic system, comprising:
a flow rate command calculating unit which adds (+) a flow rate command corresponding to required pressure, subtracts (−) a discharge flow rate discharged from an electronic hydraulic pump, and calculates a displacement flow rate; a flow rate control unit which generates a first pressure command corresponding to the displacement flow rate; a stall determining unit which determines a stall based on a first rate of change of the flow rate command, and a second rate of change of the discharge flow rate; a flow rate pressure generating unit which generates a working fluid pressure value corresponding to the discharge flow rate; a gradient limiting unit which generates a limit pressure command so as to limit an increasing gradient of the working fluid pressure value; a selecting unit which sets the limit pressure command to a second pressure command when a stall is determined by the stall determining unit; and a minimum pressure setting unit which selects a small value of the first pressure command and the second pressure command as a final pressure command so as to control an electronic proportional control valve.