WOLFRAM SYSTEM MODELER

SpoolHDoublePilotOperated

Model of a hydraulic spool

Diagram

Wolfram Language

In[1]:=
SystemModel["Hydraulic.Utilities.SpoolHDoublePilotOperated"]
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Information

This is a model of a hydraulic spool with two additional pilot ports. It has four input pressure signals and y is the current spool opening.


Normalization of the characteristic curve

The opening of the valve depends on the pressure difference, dP, which depends on the pressures according to the equation below:



where
:Pressure difference used for computing the spool position
:Pressure at port a
:Pressure at port b
:Pressure at pilot port a
:Pressure at pilot port b
:Pilot ratio for pilot port a
:Pilot ratio for pilot port b

The parameter pOpen defines the pressure difference when the valve starts to open and the parameter pSwitch defines the pressure at which the valve is fully open. The dynamics of the spool are a first-order system with the time constant t1.

Parameters (7)

pOpen

Value: 10000.0

Type: Pressure (Pa)

Description: Opening pressure

pSwitch

Value: 500000.0

Type: Pressure (Pa)

Description: Switching pressure

t1

Value: 0.1

Type: Time (s)

Description: Time constant for first-order system

kpa

Value: 1

Type: Real

Description: Pilot ratio for pilot port a; a positive value helps port_a

kpb

Value: 1

Type: Real

Description: Pilot ratio for pilot port b; a positive value helps port_b

yMax

Value: 1

Type: Real

Description: Upper limit for output value

yMin

Value: -1

Type: Real

Description: Lower limit for output value

Connectors (5)

y

Type: RealOutput

port_b

Type: Port_b

port_a

Type: Port_a

port_pilot_a

Type: Port_a

port_pilot_b

Type: Port_a

Components (15)

const

Type: Constant

limiter2

Type: Limiter

firstOrder

Type: FirstOrder

limiter1

Type: Limiter

division

Type: Division

pressure_b

Type: PressureSensor

pressure_a

Type: PressureSensor

deadZone

Type: DeadZone

gain1

Type: Gain

gain2

Type: Gain

pressure_pilot_a

Type: PressureSensor

pressure_pilot_b

Type: PressureSensor

add1

Type: Add

add2

Type: Add

add3

Type: Add