MATLAB & Simulink

meanchildlikeΜηχανική

31 Οκτ 2013 (πριν από 3 χρόνια και 11 μήνες)

95 εμφανίσεις

LOGIKA & PEMROGRAMAN
KOMPUTER


MATLAB

& Simulink


PEMBENTUKAN SISTEM KONTROL

(Wayan Nata Septiadi,ST)


TEKNIK MESIN

FAKULTAS TEKNIK UNUD

2009

Some Advanced Features


Creating hierarchical models using subsystems.


Writing S
-
functions for Customization & Creating
new blocks.


Implementation of Conditions & Logics.


Importing CAD models to SimMechanics.


Creating Virtual Worlds & Animations.


Soft Computing in Control.


Real
-
Time Technology & Hardware in the Loop
Simulations.

Example: A Control System

This example illustrates the modeling of a more complex
system, which is the thermodynamics of a house and its
temperature control system. This demo also illustrate the
usage of
subsystems

to create
hierarchical models
.

S
-
Functions


You can use
S
-
Functions

to
customize

and
create

your own
blocks.


An interesting example is providing
custom animations

for
Simulink block
-
diagram models.

A simple example of a
mass
-
spring sys with an
animation S
-
Function

is provided
as a demo named
dblcart1
in the software documentation.


A general M
-
file S
-
function template
is also provided in:
C:
\
MATLAB
\
toolbox
\
simulink
\
blocks
\
sfuntmpl.m


which can be used as a guide to write M
-
file S
-
functions.
For more information see the separate
Writing S
-
Functions

PDF guide.

Implementation of

Conditions &Logics


Simulink:


Conditionally Executed Subsystems:


enabled/triggered/triggered
-
enabled subsystems


Control Flow Statements & Blocks



StateFlow:

For implementation of more complex Flow Control
Logics (Event
-
controlled models)

SimMechanics & CAD Softwares

Virtual Reality Toolbox

SimMechanics



What Is SimMechanics?


SimMechanics is a block diagram modeling
environment for the engineering design and
simulation of rigid body machines and their
motions, using the standard Newtonian
dynamics of forces and torques.

Physical vs. Mathematical
Modeling



Simulink (normal) blocks:

represent
mathematical operations or operate on signals,




Physical Modeling blocks:

represent
physical components or relationships directly,


Note:

Sensors & Actuators

are used to connect
these two kinds of blocks.

SimMechanics Analysis Modes:


Forward Dynamics analysis:

integrates applied
forces/torques, maintaining imposed constraints, and
obtains resulting motions.



Inverse Dynamics analysis:

finds the
forces/torques necessary to produce user
-
specified
motions in topologically open systems.


Kinematics analysis:

finds the forces/torques
necessary to produce user
-
specified motions in
topologically closed (loop) systems.



Trimming analysis:

searches for steady or
equilibrium states of a system.

SimMechanics Block Libraries


Bodies Library


Joints Library


Constraints & Drivers
Library


Sensors & Actuators
Library



Force Elements
Library


Utilities Library

Essential Steps to Build a Model

1.
Select Ground, Body, and Joint blocks.

2.
Position and connect blocks.

3.
Configure Body blocks.

4.
Configure Joint blocks.

5.
Select, connect, and configure Constraint and
Driver blocks.

6.
Select, connect, and configure Actuator and
Sensor blocks.

7.
Encapsulate subsystems.


Example#1

Modeling a Double Pendulum

Example#2


One Degree of Freedom Mass
-
Spring
-
Damper System






Solution Methods:

MATLAB:

Solving the DE with an IVP/ODE solver

Control Toolbox:

Transfer Fcn, State Space Modeling

Simulink:

DE
-
solving, Transfer Fcn, State Space

SimMechanics:

Physical Modeling



Using Body Spring & Damper

Using Joint Spring & Damper

Using Sensor
-
Actuator Feedback

Assignment

2
-
D Bounce & Pitch Vehicle Model



Model the suspension system physically using
SimMechanics.


Compare the modeling approach with the
mathematical one, done previously using Simulink.