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一个很棒的网络控制系统仿真软件

-----------------------------------------------
 TrueTime version 1.13
 Example: Distributed Control System
 Directory: $DIR/examples/distributed
-----------------------------------------------

1. INTRODUCTION

This example simulates distributed control of a DC-servo. The example
contains four computer nodes, each represented by a TrueTime kernel
block. An time-driven sensor node samples the process periodically and
sends the samples over the network to the controller node. The control
task in this node calculates the control signal and sends the result
to the actuator node, where it is subsequently actuated. The
simulation also involves an interfering node sending disturbing
traffic over the network, and a disturbing high-priority task
executing in the controller node.


2. COMPILING THE SIMULATION FILES

Before starting Matlab, you must set the environment variable TTKERNEL
to point to the directory with the TrueTime kernel files:

    Unix/Linux: > export TTKERNEL=$DIR/kernel
    Windows:  Control Panel / System / Advanced / Environment Variables

After starting Matlab, you must also add the directories $DIR/kernel and
$DIR/kernel/matlab to your Matlab path. You could for instance do this in
your startup script as follows:

    addpath(getenv('TTKERNEL'))
    addpath([getenv('TTKERNEL') '/matlab'])

As described in the reference manual it is possible to write a
TrueTime simulation (i.e. the code functions for the tasks and the
initialization commands) either as m-files or as C++ functions. Both
approaches are provided for this example and the compilations needed
for the respective alternatives are described below.

2.1 Matlab version
   
    The files for Matlab-simulation of the example are located in the
    directory $DIR/examples/distributed/matlab. All necessary
    compilation is performed by the m-file makedist.m. Run this file
    from the Matlab command prompt:

    >> makedist

    NOTE: The makedist-file only needs to be run once. No
    re-compilation is needed after changing code functions or
    initialization commands.

2.2 C++ version
    
    The files for C++-simulation of the example are located in the
    directory $DIR/examples/distributed/c++. Compilation of
    the init scripts of the four computer blocks is performed by the
    m-file makedist.m. Run this file from the Matlab command prompt:

    >> makedist
    
    NOTE: If changes are made to the code functions or the
    initialization commands, the affected init scripts need to be
    re-compiled. Copy and paste from makedist.m to compile the
    relevant files individually.
    

3. EXPERIMENTS  

Open the model distributed.mdl to run the simulation. 

 - Run a first simulation without disturbing traffic and without
   interference in the controller node. This is obtained by setting the
   variable BWshare in the code function of the interfering node to
   zero, and by commenting out the creation of the task 'dummy' in
   controller_init. In this case we will get a constant round-trip delay
   and satisfactory control performance. Study the network schedule and
   the resulting control performance.

 - Switch on the disturbing node and the interfering task in the
   controller node. Set the variable BWshare to the percentage of the
   network bandwidth to be used by the disturbing node. Again study the
   network schedule and the resulting control performance. Experiment
   with different network protocols and different scheduling policies in
   the controller node.