SimHydraulics
®
Release Notes
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®
SimHydraulics
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Release Notes
Summary by Version ............................... 1
Contents
Version 1.7 (R2010a) SimHydraulics Software
Version 1.6 (R2009b) SimHydraulics Software
Version 1.5 (R2009a) SimHydraulics Software
Version 1.4 (R2008b) SimHydraulics Software
Version 1.3 (R2008a) SimHydraulics Software
Version 1.2.1 (R2007b) SimHydraulics Software
Version 1.2 (R2007a) SimHydraulics Software
Version 1.1 (R2006b) SimHydraulics Software
Version 1.0 (R2006a+) SimHydraulics Software
Compatibility Summary for S imHydraulics
Software
........................................ 31
........ 4
........ 9
........ 11
........ 13
........ 16
...... 19
........ 20
........ 26
....... 29
iii
iv Contents
SummarybyVersion
This table provides quick access to what’s new in each version. For
clarification, see “Using Release Notes” on page 2 .
SimHydraulics®Release Notes
Version
(Release)
Latest Versi
V1.7 (R2010a
V1.6 (R2009b)
V1.5 (R2009a)
V1.4 (R2
V1.3 (R2008a)
V1.2.1 (R2007b)
on
)
008b)
New Features
and Changes
Yes
Details
Yes
Details
Yes
Details
Yes
Details
Yes
Details
Yes
ils
Deta
Version
Compatibilit
Consideratio
Yes
Summary
No Bug Reports
No Bug Repor
No Bug Reports
No Bug Reports
No Bug R
y
ns
Fixed Bugs
and Known
Problems
Bug Reports
Includes fix
Includes fixes
ts
Include
Includes fixes
Includes fixes
Incl
sfixes
eports
udes fixes
es
Related
Documentation
at Web Site
Printable R elease
Notes: PDF
Current product
documentation
No
No
No
No
No
2 (R2007a)
V1.
Yes
Details
Yes
Summary
Bug Reports
Includes fixes
No
1
SimHydraulics®Release Notes
Version
(Release)
V1.1 (R2006b)
V1.0 (R2006a+)
New Features
and Changes
Yes
Details
Yes
Details
Version
Compatibility
Considerations
No Bug Reports
Not applicable
Fixed Bugs
and Known
Problems
Includes fixes
Bug Reports No
Related
Documentation
at Web Site
No
Using Release Notes
Use release notes when upgrading to a newer version to learn about:
• New features
• Changes
• Potential impact on your existing files and practices
Review the release notes for other MathWorks™ products required for this
product (for example, MATLAB
bugs, or compatibility considerations in other products impact you.
®
or Simulink®). Determine if enhancements,
If you are upgrading from a software version other than the m ost recent one,
review the current release notes and all interim versions. For example, when
you upg rade from V1.0 to V1.2, review the release notes for V1.1 and V1.2.
What Is in the Release Notes
New Features and Changes
• New functionality
• Changes to existing functionality
2
SummarybyVersion
Version Compatibility Con si derations
When a new feature or change introduces a reported incompatibility between
versions, the Compatibility Considerations subsection explains the
impact.
Compatibility issues reported after the product release appear under Bug
Reports at The MathWorks™ Web site. Bug fixes can sometimes result
in incompatibilities, so review the fixed bugs in Bug Reports for any
compatibility impact.
Fixed Bugs and Known Problems
The MathWorks offers a user-searchable Bug Reports database so you can
view Bug Reports. The development team updates this database at release
time and as more information becomes available. Bug Reports include
provisions for any known workarounds or file replacem ents. Information is
available for bugs existing in or fixed in Release 14SP2 or later. Information
is not avail able for all bugs in earlier releases.
Access Bug Reports using y our MathWorks Account.
3
SimHydraulics®Release Notes
Version 1.7 (R2010a) SimHydraulics Software
This table summarizes what’s new in Version 1.7 (R2010a):
New Features and
Changes
Yes
Details below
Version
Compatibility
Considerations
Yes—Details labeled
as Compatibility
Considerations,
below. See also
Summary.
New features and changes introduced in this version are
• “Simplified Blocks for Real-Time Simulation” on page 4
• “Low-Pressure Blocks with Variable Elevations” on page 5
• “Cartridge Valve Modeling Blocks ” on page 5
• “Lubrication System Modeling Blocks” on page 6
• “Centrifugal Pump Enhancement” on page 6
• “Initial Piston Position in the Single-Acting Hydraulic Cylinder Block”
on page 6
• “Changes to SimHydraulics Demos” on page 7
Fixed Bugs an d
Known Problems
Bug Reports
Includes fixes
Related
Documentation at
Web Site
Printable Release
Notes: PDF
Current product
documentation
Simplified Blocks for Real-Time Simulation
The following new blocks implement simplified models that reproduce only
basic functionality in exchange for better numerical efficiency:
• Single-Acting Hydraulic Cylinder (Simple) block represents a simplified
version of a single-acting hydraulic cylinder. The model assumes fluid
compressibility, friction, and leakages to be negligible. The hard stops
areassumedtobefullyinelastic,toeliminateanypossibleoscillationsat
the end of the stroke.
• Double-Acting Hydraulic Cylinder (Simple) block represents a simplified
version of a double-acting hydraulic cylinder. The model assumes fluid
4
Version 1.7 (R2010a) SimHydraulics®Software
compressibility, friction, and leakages to be negligible. The hard stops
areassumedtobefullyinelastic,toeliminateanypossibleoscillationsat
the end of the stroke.
• 4-Way Ideal Valve block represents a 4-way critically-centered valve. Initial
openings of all orifices are set to 0, which significantly simplifies the model.
• Valve Actuator block represents a simplified version of a valve actuator,
built as a first-order lag.
Use these blocks for real-time and HIL (hardware-in-the-loop) simulation, if
such simplifications are acceptable.
Low-Pressure Blocks with Variable Elevations
Additional blocks in the Low-Pressure Blocks library incorporate elevation
information and let you specify elevations as input signals, rather than as
block parameters:
• Resistive Pipe LP with Variable Elevation block represents a hydraulic
pipeline which accounts for friction losses and port elevations.
• Hydraulic Pipe LP with Variable Elevation block represents a hydraulic
pipeline with resistive, fluid compressibility, and elevation propertie s.
Use these blocks for low-pressure system simulation in which the pipe ends
change their positions with respect to the reference plane.
Cartridge Valve Modeling Blocks
Two new blocks extend the cartridge valve modeling capabilities:
• Cartridge Valve Insert with Conical S eat block represents an insert of a
hydraulic cartridge valve consisting of a poppet intera ctin g with the conical
seat.
• Hydraulic 4-Port Cartridge Valve Actuator block represents double-acting
hydraulic valve actuator driven by four pressures. Use this block as a pilot
actuator for cartridge valves, as well as pilot-operated pressure and control
valves, in applications where all the forces, except spring and pressure
forces, and flow consumption can be neglected.
5
SimHydraulics®Release Notes
There are also additional parameters in the Hydraulic Cartridge Valve
Actuator block that account for initial conditions and dynamic properties of
themodel. Seetheblockreferencepagefordetails.
Lubrication System Modeling Blocks
The following blocks hav e been added to facilitate modeling lubrication
systems:
• Centrifugal Force in Rotating Cylinder block simulates centrifugal forces
• Rotating Pipe block models a hydraulic pipeline represented as a short bore
exerted by fluid on a piston if the cylinder rotates about its symmetry axis.
Such cylinders are used in control mechanisms of various friction clutches,
brakes, square-jaw positive clutches, dog clutches, and so on. No inertial
effects are considered in the model. In other words, the angular velocity is
assumed to be constant or changing at very low speed.
drilled through a shaft at some angle to its axis, or as a short pipe that
connects actuator or bearings, mounted on the shaft, with the channel
inside the shaft. Such connections are typical for lubrication systems and
for hydraulically-operated clutches and mechanisms. The shaft angular
velocity is assumed to be constant or changing at very low speed.
Centrifugal Pump Enhancement
The Centrifugal Pump block now contains additional parameters that let you
simulate operation at zero angular velocity. See the block reference page for
details.
Initial Piston Position in the Single-Acting Hydraulic
Cylinder Block
The Piston initial position parameter in the block dialog box has been
renamed to Initial distance between piston and cap, and the way it is
used in the block output has been changed.
In previous versions, the Piston initial position parameter let you specify
the distance that the piston is extended at the beginning of simulation by
setting the piston initial position to any point w ithin its stroke, but this value
was not included in calculating the rod displacement. In other words, the
6
Version 1.7 (R2010a) SimHydraulics®Software
rod displacement output at the block’s physical signal port was with respect
to the initial piston position.
In the current version, the Initial distance between piston and cap
parameter value is included in calculating the rod displacement output by
the block:
x
= x0+ x
pst
p
where
x
pst
x
0
x
p
Rod displacement output by the physical signal port
Initial distance between piston and cap
Rod displacement with respect to its initial position
For details, see the block reference page.
Compatibility Considerations
The block output changes because of the ne w way it calculates rod
displacement. It used to start out at zero but now starts out at the initial
position. If you have used this block with nonzero initial position in your
models, the block output will differ by this value:
x
= x0+ x
new
where
x
new
x
old
x
0
old
Rod displacement output by the physical signal port in the current
version
Rod displacement output by the physical signal port in the
previous version
Piston initial position value
Changes to SimHydraulics Demos
The following demos have been added in Version 1.7:
7
SimHydraulics®Release Notes
Demo Name
Diesel Engine In-Line Injection System
(
sh_diesel_engine_in_line_injection_system)
Fuel Supply System with Variable Elevation
(
sh_fuel_supply_system_with_variable_elevations)
Hydraulic Actuation System with Cartridge Valves
(
sh_actuation_system_cartridge_valve)
Hydraulic Closed-Loop Actuator with Fixed-Step
Integration
(
sh_hydraulic_closed_loop_actuator_fixed_step )
Description
Simulates an in-line multi-element
injection system. The objective of the
simulation is to investigate the entire
system operation.
Simulates a three-tank fuel supply
systemwheresidetanksperiodically
change elevations during the simulation
cycle.
Simulates a complex actuation system
equipped w ith cartridge valves.
Represents two versions of the
same closed-loop hydraulic actuator.
In the second version, standard
SimHydraulics
®
blocks are replaced
with their simplified versions and
the model is optimized for fixed-step
integration.
8
Version 1.6 (R2009b) SimHydraulics®Software
Version 1.6 (R2009b) SimHydraulics Software
This table summarizes what’s new in Version 1.6 (R2009b):
New Features and
Changes
Yes
Details below
Version
Compatibility
Considerations
No Bug Reports
New features and changes introduced in this version are
• “Additional 4-Way and 6-Way Directional Valve Configurations” on page 9
• “Additional Low-Pressure Blocks” on page 9
• “New Ball Valve with Conical Seat Block” on page 10
Fixed Bugs an d
Known Problems
Includes fixes
Related
Documentation at
Web Site
No
Additional 4-Way and 6-Way Directional Valve
Configurations
Nine 4-way directional valve block s and one 6-way directio na l valve block
have been added to the Directional Valves library, and the original 4-Way
Directional Valve block has been modified, to enable additional valve
configurations. For more information, see “Modeling Directional Valves” in
the SimHydraulics User’s Guide, as well as individual block reference pages.
Additional Low-Pressure Blocks
The following blocks have been added to the Low-Pressure Blocks library:
• Variable Head Two-Arm Tank block represents a tank with constant
pressurization and volume-dependent fluid level. The tank has two
hydraulic p orts and a physical signal port, which exports the volume of
fluid in the tank.
• Variable Head Three-Arm Tank block represents a tank with constant
pressurization and volume-dependent fluid level. The tank has three
9
SimHydraulics®Release Notes
Both blocks account for the fluid level change caused by the volume variation,
as well as for pressure loss in the connecting p ipes that can be caused by
a filter, fittings, or some other local resistance. You can specify pipeline
diameter, pressure loss coefficient, and elevation information for each
hydraulic port separately.
New Ball Valve with Co nical Seat Block
The new Ball Valve with Conical Seat block in the Flow Control Valves library
models a ball valve created by a spherical ball and a conical seat. The valve is
characterized by the ball d iameter, cone angle, and o r if ice diameter.
hydraulic p orts and a physical signal port, which exports the volume of
fluid in the tank.
10
Version 1.5 (R2009a) SimHydraulics®Software
Version 1.5 (R2009a) SimHydraulics Software
This table summarizes what’s new in Version 1.5 (R2009a):
New Features and
Changes
Yes
Details below
Version
Compatibility
Considerations
No Bug Reports
New features and changes introduced in this version are
• “New Low-Pressure Blocks Library” on page 11
• “Changes to SimHydraulics Demos” on page 12
Fixed Bugs an d
Known Problems
Includes fixes
Related
Documentation at
Web Site
No
New Low-Pressure Blocks Library
The Low-Pressure Blocks library, added in this release, contains five new
blocks that incorporate elevation information:
• Constant Head Tank block represents a tank where pressurization and
fluid level remain constant regardless of vo lume change. T h e block
accounts for the fluid level elevation with respect to the tank bottom, as
well as for pressure loss in the connecting pipe that can be caused by a
filter, fittings, or some other local resistance.
• Variable Head Tank block represents a tank with constant pressurization
and volume-dependent fluid level. The block accounts for the fluid level
change caused by the volume variation, as well as for pressure loss in
the connecting pipe that can be caused by a filter, fittings, or some other
local resistance.
• Resistive Pipe L P block represents a hydraulic pipeline which accounts for
friction losses and port elevations.
• Hydraulic Pipe LP block repre s en ts a hydraulic pipeline with resistive,
fluid compressibility, and elevation properties.
• Segmented Pipe LP block represents a hydraulic pipeline with resistive,
fluid inertia, fluid compressibi lity, and elevation properties.
11
SimHydraulics®Release Notes
These blocks enable additional applications, such as low-pressure fluid
transportation system simulation.
Changes to SimHydraulics Demos
The following demos have been added in Version 1.5:
Demo Name
Water Supply System
sh_water_supply_system)
(
Fluid Transportation System with Three Tanks
(
sh_three_tanks)
Description
The water supply system modeled in the demo
consists of three pumping stations located at
45, 25, and 30 m with respect to the reference
plane, respectively. All three stations are
expected to pump water in a tank located at 61
m. The objective of simulation is to determine
steady-state flow rates and pressures.
The demo illustrates a classical problem of
fluid transportation: to determine flow rates,
pressures, and fluid volumes in a system built
of three constant head tanks. The tanks are
located at dif ferent elevations and connected
with pipelines combined together in a common
node. The pipelines are simulated with the
Segmented Pipeline LP block, which accounts
for hydraulic losses, fluid inertia, and the head
due to different node elevations.
12
Version 1.4 (R2008b) SimHydraulics®Software
Version 1.4 (R2008b) SimHydraulics Software
This table summarizes what’s new in Version 1.4 (R2008b):
New Features and
Changes
Yes
Details below
Version
Compatibility
Considerations
No Bug Reports
New features and changes introduced in this version are
• “Explicit Solvers Now Available for SimHydraulics Models” on page 13
• “New Variable-Displacement Hydraulic Machine Block” on page 13
• “Improved Usability of the 4-Way Directional Valve Block” on page 14
• “Changes to SimHydraulics Demos” on page 14
Fixed Bugs an d
Known Problems
Includes fixes
Related
Documentation at
Web Site
No
Explicit Solvers Now Available for SimHydraulics
Models
Using explicit solvers has been implemented for models that include
Simscape™ and SimHydraulics blocks. For more information, see “Working
with Solvers” in the Simscape documentation.
New Variable-Displacement Hydraulic Machine Block
The Variable-Displacement Hydraulic Machine block, able to work as a
pump or a motor, enables modeling variable-efficiency machines based on
manufacturer’s data sheets. The machine displacement is controlled by the
signal provided through the physical signal port C. The machine efficiency is
simulated by im pl em enting regime-dependable leakage and friction torque
based on the experimentally established correlations between the machine
efficiencies and pressure, angular velocity, and displacement.
13
SimHydraulics®Release Notes
Improved Usability of the 4-Way Directional Valve
Block
The 4-Way Directional Valve block dialog box has been reorganized using tabs
to improve usability. Use the Initial openings tab to set all the initial orifice
openings. The Basic param eters tab contains the model parameterization
options and the corresponding parameters. The parameters themselves have
not changed.
Changes to SimHydraulics Demos
The following demos have been added in Version 1.4:
Demo Name
Hydraulic Drill-Ream Actuator
(
sh_drill_ream_actuator)
Front-Loader Actuation System
(
sh_front_loader_actuation_system)
Pipeline System with Centrifugal Pump
(
sh_pipeline_system_centrifugal_pump)
Description
The actuator is intended to drive a machine
tool working unit performing a sequence
of three technological operations: coarse
drilling, fine drilling, and reaming. The
actuator speed is controlled by one of three
pressure-compensated flow control valves
metering out return flow from the cylinder.
The selection of an appropriate flow control
is performed by directional valves that are
activated by a control unit.
The model shows a simplified version of an
actuation system consisting of the lift and tilt
cylinders. Each of the cylinders is controlled by
an open center, 5-way, 3-position directional
valve. The valves are connected in series
through their unloading branch in such a
way that the system pump is unloaded when
both command levers are in neutral position.
If either tilt or lift command is applied, the
unloading path is closed.
The demo represents a typical pipeline system
with the centrifugal pump. The system is
built of three manifolds connected with hoses.
The combination of valves installed inside
manifoldsallowsflowratetobedirected
14
Version 1.4 (R2008b) SimHydraulics®Software
through different branches. The manifold
models account for local resistances, elbows,
and cylindrical channels.
Also, the Variable Volume Chamber Test Rig
(
sh_variable_chamber_test_rig) demo has been renamed to Variable
Volume Piston Chamber Test Rig, and all the Variable Volume Chamber
blocks in it have been replaced with Piston Chamber b locks.
15
SimHydraulics®Release Notes
Version 1.3 (R2008a) SimHydraulics Software
This table summarizes what’s new in Version 1.3 (R2008a):
New Features and
Changes
Yes
Details below
Version
Compatibility
Considerations
No Bug Reports
New features and changes introduced in this version are
• “Trimming Now Available for SimHydraulics Models” on page 16
• “New Cartridge Valve Insert and Hydraulic Cartridge Valve Actuator
Blocks” on page 16
• “Additional Configurations for the Centrifugal Pump Block” on page 17
• “Additional Fluids Available in the Hy draulic Fluid Block” on page 17
Fixed Bugs an d
Known Problems
Includes fixes
Related
Documentation at
Web Site
No
Trimming Now Available for SimHydraulics Models
Finding and managing operating points by trimming has been implemented
for models that include Simscape and SimHydraulics blocks. Simulink
Control Design™ product is required for using this functionality. For more
information, see Trimming Simscape Models in the Simscape d ocumentation.
®
16
New Cartridge Valve Insert and Hydraulic Cartridge
Valve Actuator Blocks
Two new blocks facilitate modeling cartridge valves:
• Cartridge Valve Insert block in the Directional Valves library represents
an insert of a hydraulic cartridge valve consisting of a poppet interacting
with the sleeve seat. The poppet position is determined by pressures at
ports A , B, and X and force of the spring. This is a structural model based
on a Variable Orifice block and a Hydraulic Cartridge Valve Actuator
block, described below.
Version 1.3 (R2008a) SimHydraulics®Software
• Hydraulic Cartridge Valve Actuator block in the Valve Actuators library
represents a double-acting hydraulic valve actuator driven by three
pressures. Use this block as a pilot actuator for cartridge valves, as well
as pilot-operated pressure and control valves in applications where a ll
the forces, except spring and pressure forces, and flow consumption can
be neglected.
Additional Configurations for the Centrifugal Pump
Block
The Centrifugal Pump block represents a centrifugal pump of any type as a
data-sheet-based model. Depending on data listed in the manufacturer’s
catalogs or data sheets for your particular pump, you can now choose one of
the following model parameterization options:
•
By approximating polynomial — Provide va lues for the polynomi al
coefficients. These values can be determined analytically or experimentally,
depending on the data available. This is the default method, equivalent to
the implementation available in the previous release.
•
By two 1D characteristi cs: P-Q and N-Q — Provide tabulated
data of pressure differential and brake power versus pump delivery
characteristics. The pressure differential and brake power are determined
by one-dime nsional t able lookup. You have a choice of three interpolation
methods and two extrapolation methods.
•
By two 2D characteristi cs: P-Q-W and N-Q-W — Provide tabulated
data of pressure differential and brake power versus pump delivery
characteristics at d ifferent angular velocities. The pressure differential and
brake pow er are determined by two-dimensional table lookup. You have a
choice of three interpolation methods and two extrapolation methods.
Additional Fluids Available in the Hydraulic Fluid
Block
The follow i ng predefined fluids have been added to the Hydraulic Fluid block:
•
ISO VG 22 (ESSO UNIVIS N 22)
• ISO VG 46 (ESSO UNIVIS N 46)
• Brake fluid DOT3
17
SimHydraulics®Release Notes
• Brake fluid DOT4
• Brake fluid DOT5
• Water
See the block reference page for more information. The “Examples” section
shows how you can get information on the fluids and their properties.
18
Version 1.2.1 (R2007b) SimHydraulics®Software
Version 1.2.1 (R2007b) Si mHydraulics Software
This table summarizes what’s new in Version 1.2.1 (R2007b):
New Features and
Changes
Yes
Details below
Version
Compatibility
Considerations
No Bug Reports
New features and changes introduced in this version are described here:
Fixed Bugs an d
Known Problems
Includes fixes
Related
Documentation at
Web Site
Printable Release
Notes: PDF
Current product
documentation
Code Generation Now Available for SimHydraulics
Models
Code generation has been implemented for models that include Simscape
and SimHydraulics blocks. For more information, see “Generating Code” in
theSimscapedocumentation.
19
SimHydraulics®Release Notes
Version 1.2 (R2007a) SimHydraulics Software
This table summarizes what’s new in Version 1.2 (R2007a):
New Features and
Changes
Yes
Details below
Version
Compatibility
Considerations
Yes—Details labeled
as Compatibility
Considerations,
below. See also
Summary.
New features and changes introduced in this version are
• “SimHydraulics Now Requires Simscape” on page 20
• “Block Libraries Moved from SimHydraulics to Simscape” on page 20
• “Sharing Models Using the Simscape Editing Modes” on page 21
• “New SimHydraulics Blocks” on page 21
• “Initial Conditions Added for Certain Blocks” on page 21
• “Block Library Links Must Be Resolved” on page 22
• “Changes to SimHydraulics Demos” on page 23
Fixed Bugs an d
Known Problems
Bug Reports
Includes fixes
Related
Documentation at
Web Site
No
SimHydraulics Now Requires Simscape
SimHydraulics now depends on and requires Simscape, the platform for
all Physical Modeling products, which includes common Physical Modeling
utilities and block libraries.
20
Block Libraries Moved from SimHydraulics to
Simscape
The Foundation and Utilities block libraries that used to be included in
SimHydraulics (V1.0 and V1.1) are now part of Simscape produc t.
Version 1.2 (R2007a) SimHydraulics®Software
Sharing Models U
When working wit
Simscape editin
• The Restricted
does not requi
parameters, b
• TheFullmoder
license. It a
New SimHydr
The new bloc
• Centrifug
• Single-Ac
• Double-A
• Hydrauli
• Hydraul
• Valve Hy
• Spool Or
ctingRotaryActuator
c Single-Acting Valve Actuator
ic Double-Acting Valve Actuator
draulic Force
ifice Hydraulic Force
h SimHydraulics models, you now have a selection of two
g modes that allow full o r restricted editing of models.
mode requires SimHydraulics software to be installed, but
re a license. It allows you change a limited set of model
ut not the blocks or connections, in a SimHydraulics model.
equires SimHydraulics software to be installed with a
llows you to change anything in a SimHydraulics model.
aulics Blocks
ks introduced in Version 1.2 are listed below:
al Pump
ting Rotary A ctuator
sing the Simscape Editing Modes
Initia
Severa
use in
Note t
(V1.0
comp
the b
• Gas-
• Spr
• Con
• Va
l Conditions Added for Certain Blocks
l blocks now have a parameter that specifies the initial condition for
computing the block’s initial state at the beginning of a simulation run.
hat some of these blocks, which used to be included in SimHydraulics
and V1.1), are now part of Simscape product. The following is a
lete list of blocks where you can specify an initial condition through
lock dialog box:
Charged Accumulator
ing-Loaded Accumulator
stant Volume Chamber
riable Volume Chamber
21
SimHydraulics®Release Notes
• Fluid Inertia
• Inertia
• Mass
• PS Integrator
• Rotational Spring
• Translational Spring
For details, see the block reference pages.
Compatibility Considerations
In this version, there is a difference in the way the initial conditions are
computed, and as a result, the blocks that have an initial condition parameter
work differently than they used to in the previous version.
Block Library Links Must Be Resolved
All SimHydraulics blocks in your models must n ow have resolved block
library links. You can neither disable nor break these library links. This is a
global requirement of Simscape modeling environment. Consult the Simscape
documentation for further details.
22
Compatibility Considerations
If you have an existing Sim Hydraulics model with disabled or broken lin ks
from SimHydraulics blocks to the SimHydraulics block library, you must
restore all the broken block library links for your model to be valid.
If you have disabled or broken the SimHydraulics library link for blocks that
you have customized and want to keep these modified blocks in your model,
you must move these modified blocks to your own custom library or libraries,
then copy the block instances that you need to your model.
You must still restore the block link to its parent library, whether that parent
library is SimHydraulics or your own.
Version 1.2 (R2007a) SimHydraulics®Software
Changes to SimHy
The following de
Demo Name
HydraulicActuatorwithTwo-Chamber
Snubbers
(
sh_actuator_with_2_chamber_snubbers)
Digital Hydraulic Actuator
(
sh_digital_hydraulic_actuator)
mos have been added in Version 1.2:
draulics Demos
Description
The reciprocal actuator demonstrated in this
model is equipped with snubbers (cushions) on
both sides of the cylinder.
The d ig ita l hydraulic actuator consists of three
double-acting cylinders mounted in the same
shell and interconnected through the hard
stops.
HydraulicActuatorwithLoad-Sensing
Variable-Displacement Pump
(
sh_hydraulic_actuator_load_sensing_pump)
The circuit demonstrates usage of a
load-sensing and pressure-limiting unit in a
conventional reciprocal system with variable
load on the forward stroke.
HydraulicActuatorwithTelescopicCylinder
(
sh_hydraulic_actuator_telescopic_cylinder)
The actuator is built around a telescopic
hydraulic cylinder, which is equipped with
three rods interacting with each other through
hard stops.
Closed-Circuit Reciprocal Actuator
(
sh_hydraulic_closed_circuit_reciprocal_actuator)
The dem
rohydraulic actuator driven by a
elect
ble-velocity electrical motor.
varia
o illustrates a closed-circuit
r-Assisted Steering Mechanism
Powe
hydraulic_power_assisted_steering
(
sh_
The m
)
powe
all i
raulic System with Servo-Valve
Hyd
_hydraulic_system_with_servo_valve
(
sh
The
)
ser
val
am
draulic Transmission with Secondary
Hy
ntrol
Co
sh_hydraulic_transmission_secondary_control)
(
ydrostatic Transmission with Shuttle Valve
H
(
sh_hydrostatic_transmission_shuttle_valve)
Th
se
w
The circuit demonstrates a hydrostatic
transmission with a shuttle valve in the control
unit.
odel represents a simplified version of a
r-assisted steering mechanism showing
ts major parts.
demo represents the model of a two-stage
vo-valve with a 4-way, 3-position spool
ve in the power stage and a flapper-nozzle
plifier in th e pilot stage.
e system demonstrates usage of the so-called
condary control in hydrostatic transmissions
ith a variable-displacement motor.
23
SimHydraulics®Release Notes
Hydraulic Circuit with Load-Sensing Velocity
Control
(
sh_load_sensing_velocity_control)
Oscillating Hydraulic Mechanism
(
sh_oscillating_hydraulic_mechanism)
Reciprocal Actuator with Counterbalance
Valves
(
sh_reciprocal_actuator_cntrb_valves)
Sequencing Circuit with Rotary Actuators
(
sh_sequencing_circuit_rotary_actuators)
The following demos that used to be in SimHydraulics 1.1 are now part
of Simscape product:
Demo Name
Simple Mechanical System
(
ssc_simple_mechanical_system)
The circuit is equipped with the load-sensing
velocity regulator installed between the pump
and directional valve.
The oscillating hydraulic m echanism consists
of a single-acting hydraulic rotary actuator,
winch, flow control valve, two-position
electrohydraulic valve, and power and control
units.
The actuator is built of a double-acting
cylinder, directional valve, flow control,
block of counterbalance valves, power unit,
replenishment arrangement, and a control
unit.
The sequence circuit is based on four check
valves installed in both pressure and return
lines of the second rotary actuator.
Description
This model is built of both rotational and
translational mechanical blocks to illustrate
their use in a system.
Mechanical System with Translational Friction
ssc_mechanical_system_translational_friction )
(
Mechanical System with Translational Hard
Stop
(
ssc_mechanical_system_translational_hardstop )
24
Thedemoillustratesamassloadedwitha
spring and viscous damper.
The demo illustrates two masses interacting
through a hard stop.
Version 1.2 (R2007a) SimHydraulics®Software
Mechanical Rotational System with Stick-Slip
Motion
(
ssc_rot_system_stick_slip)
Linkage Mechanism
(
ssc_linkage_mechanism)
This model demonstrates a mechanical
rotational sy stem, where a load is driven by a
velocity source with a friction element between
them, and stick-slip motion is developed in the
regions of constant velocities.
The model demonstrates the use of the Lever
block in a linkage mechanism.
25
SimHydraulics®Release Notes
Version 1.1 (R2006b) SimHydraulics Software
This table summarizes what’s new in Version 1.1 (R2006b):
New Features and
Changes
Yes
Details below
Version
Compatibility
Considerations
No Bug Reports
New features introduced in this version are described here.
Fixed Bugs an d
Known Problems
Includes fixes
Related
Documentation at
Web Site
No
Linearization Support
The Simulink linmod and dlinmod commands create continuous- or
discrete-time linear time-invariant (LTI) state-space models from Simulink
models. You can now use these commands to generate an LTI state-space
model from a model containing SimHydra u li cs components.
There are two basic ways
of linearization differs depending on which method is chosen. If
is called (that is, the arguments for time, state, and input are not provided),
then consistent initial conditions are solved for in the same way as on the first
step of a simulation. If you call
important to provide it with a consistent state to linearize about. For more
information, see “Linearizing at an O pe rating Point” in the Simscape User’s
Guide.
linmod and dlinmod can be used, and the behavior
linmod(mdl)
linmod(mdl, t, x, u), it is particularly
26
New Solver Option Allows Starting Transient
Analysis from a Steady State
A new solver option allows you to specify that simulation starts from a steady
state. Steady state means that the system variables are no longer changing
with time.
If you select the Start simulation from steady state check box in the
Solver block dialog, the solver attempts to find the steady state that would
Version 1.1 (R2006b) SimHydraulics®Software
result if the inputs to the system were held constant for a sufficiently large
time, starting from the initial state obtained from the initial conditions
computation. Although the solv er tries to find the particular steady state
resulting from the given initial conditions, it is not guaranteed to do so. All
that is guaranteed is that if the steady-state solve succeeds, the state found
is a steady state (within tolerance). Simulation then starts from this steady
state.
Note If the simulation fails at or near the start time when you use the Start
simulation from steady state option, consider clearing the check box and
simulating with the plain initial conditions computation only.
Extended Functionality for Working with Physical
Units
Version 1.1 provides the following commands that help you specify the
physical units for your system:
•
pm_adddimension
• pm_addunit
• pm_getunits
Unit names are defined in the pm_units.m file, which is shipped with the
product. You can open this file to see how the physical units are defined, and
also as an example when adding your own units. This file is located in the
directory
Use the
defined in your unit registry. Use the
commandstodefineadditionalunits.
matlabroot\toolbox\physmod\pm_util\pm_util.
pm_getunits command to get an up-to-date list of units currently
pm_adddimension and pm_addunit
New SimHydraulics Blocks
The new blocks introduced in Version 1.1 are listed below:
• Annular Orifice
• Cylinder Friction
27
SimHydraulics®Release Notes
• Reservoir
• Elbow
• Pipe Bend
• T-junction
• Gradual Area Change
• Sudden Area Change
• Variable-Displacement Motor
• Variable-Displacement Pump
• Shuttle Valve
• PS Product
• PS Divide
28
Version 1.0 (R2006a+) SimHydraulics®Software
Version 1.0 (R2006a+) SimHydraulics Software
This table summarizes what’s new in Version 1.0 (R2006a+):
New Features and
Changes
Yes
Details below
Version
Compatibility
Considerations
Not applicable
New features introduced in this version are described here.
Fixed Bugs an d
Known Problems
Bug Reports No
Related
Documentation at
Web Site
Product Introduction
SimHydraulics software is a modeling environment for the engineering design
and simulation of hydraulic power and control systems within Simulink
and MATLAB. It is based on the Physical Network approach and contains
a comprehensive library of hydraulic blocks, as well as one-dimensional
translational and rotational mechanical elements and utility blocks.
SimHydraulics software key features are:
• Enables modeling and simulation of hydraulic power and control systems
in Simulink
• Provides intuitive and convenient description of multidomain models based
on physical networks
• Includes a library of hydraulic components, such as pumps, valves,
accumulators, and pipelines, that account for effects such as fluid
compressibility, turbulence transition, and fluid inertia
• Provides foundation library of hydraulic building blocks, as well as
fundamental mechanical and mathematical elements, to enable efficient
extension and customization of models
• Provides customizable library of hydraulic fluids
SimHydraulics software employs a network approach to model building.
Components in the network correspond to physical elements, such as pumps,
29
SimHydraulics®Release Notes
motors, valves, etc. The lines that join the components correspond to physical
connections that transmit power between components. Unlike traditional
Simulink block diagrams, these connections are non-directional and do not
require the user to resolve the causality of the system while building the
model. SimHydraulics libraries containmorethan75modelsofhydraulic
and mechanical components. All the models were developed to be easily
characterized by data normally available in manufacturer’s catalogs or data
sheets. Building a model of a system is analogous to assembling the actual
physical sy stem with off-the-shelf components. The end result is a hydraulic
circuit schematic in concurrence with ISO 1219 Fluid Power Standard.
SimHydraulics limitations are:
• Explicit solvers are not currently supported. Only the following solvers are
• A SimHydraulics physical network should not exist within a Simulink
supported:
ode15s, ode23t,andode14x.
algebraic loop. This means that you should not directly connect an output
of a PS-Simulink Converter block to an input of a Simulink-PS Converter
block of the same physical network.
30
• Code generation is not currently supported.
Compatibility Summary for SimHydraulics®Software
Compatibility Summar y for SimHydraulics Software
This table summarizes new features and changes that might cause
incompatibilities when you upgrade from an earlier version, or wh en you
use files on multiple versions. Details are provided in the description of the
new feature or change.
Version (Release) New Features and Changes with
Version Compatib ility Impact
Latest Version
V1.7 (R2010a)
V1.6 (R2009b)
V1.5 (R2009a)
V1.4 (R2008b)
V1.3 (R2008a)
V1.2.1 (R2007b)
V1.2 (R2007a) See the Compatibility
V1.1 (R2006b)
See the Compatibil ity
Considerations subheading
for this new feature or change:
• “Initial Piston Position in the
Single-Acting H ydraulic Cylinder
Block” on page 6
None
None
None
None
None
Considerations subheading
for these new features or changes:
• “Initial Conditions Added for
Certain Blocks” on page 21
• “Block Library Links Must Be
Resolved” on page 22
None
V1.0 (R2006a+)
Not applicable
31
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