diff --git a/simscape-model.html b/simscape-model.html index c39f8ff..0f5859e 100644 --- a/simscape-model.html +++ b/simscape-model.html @@ -4,7 +4,7 @@ "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> - + Stewart Platform - Simscape Model @@ -254,11 +254,175 @@ for the JavaScript code in this tag. HOME

Stewart Platform - Simscape Model

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Table of Contents

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1 Parameters used for the Simscape Model

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2 Simulation Configuration - Configuration reference

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+As multiple simulink files will be used for simulation and tests, it is very useful to determine good simulation configuration that will be shared among all the simulink files. +

+ +

+This is done using something called “Configuration Reference” (documentation). +

+ +

+Basically, the configuration is stored in a mat file conf_simscape.mat and then loaded in the workspace for it to be accessible to all the simulink models. +It is automatically loaded when the Simulink project is open. It can be loaded manually with the command: +

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load('mat/conf_simscape.mat');
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+It is however possible to modify specific parameters just for one Simulink file using the set_param command: +

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set_param(conf_simscape, 'StopTime', 1);
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3 Subsystem Reference

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+Several Stewart platform models are used, for instance one is use to study the dynamics while the other is used to apply active damping techniques. +

+ +

+However, all the Simscape models share some subsystems using the Subsystem Reference Simulink block (documentation). +

+ +

+These shared subsystems are: +

+
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  • Fixed_Based.slx - Fixed base of the Stewart Platform
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  • Mobile_Platform.slx - Mobile platform of the Stewart Platform
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  • stewart_strut.slx - One strut containing two spherical/universal joints, the actuator as well as the included sensors. A parameter i is initialized to determine what it the “number” of the strut.
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+These subsystems are referenced from another subsystem called Stewart_Platform.slx, that basically connect them correctly. +This subsystem is then referenced in other simulink models for various purposes. +

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4 Basic configuration for the Fixed base, Mobile Platform and Struts

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5 Sensors included in the Struts and on the Mobile Platform

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6 Inertial Sensors

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6.1 Z-Axis Geophone

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+This Matlab function is accessible here. +

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function [geophone] = initializeZAxisGeophone(args)
+    arguments
+        args.mass (1,1) double {mustBeNumeric, mustBePositive} = 1e-3 % [kg]
+        args.freq (1,1) double {mustBeNumeric, mustBePositive} = 1    % [Hz]
+    end
+
+    %%
+    geophone.m = args.mass;
+
+    %% The Stiffness is set to have the damping resonance frequency
+    geophone.k = geophone.m * (2*pi*args.freq)^2;
+
+    %% We set the damping value to have critical damping
+    geophone.c = 2*sqrt(geophone.m * geophone.k);
+
+    %% Save
+    save('./mat/geophone_z_axis.mat', 'geophone');
+end
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+ +
+

6.2 Z-Axis Accelerometer

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+This Matlab function is accessible here. +

+ +
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function [accelerometer] = initializeZAxisAccelerometer(args)
+    arguments
+        args.mass (1,1) double {mustBeNumeric, mustBePositive} = 1e-3 % [kg]
+        args.freq (1,1) double {mustBeNumeric, mustBePositive} = 5e3  % [Hz]
+    end
+
+    %%
+    accelerometer.m = args.mass;
+
+    %% The Stiffness is set to have the damping resonance frequency
+    accelerometer.k = accelerometer.m * (2*pi*args.freq)^2;
+
+    %% We set the damping value to have critical damping
+    accelerometer.c = 2*sqrt(accelerometer.m * accelerometer.k);
+
+    %% Gain correction of the accelerometer to have a unity gain until the resonance
+    accelerometer.gain = -accelerometer.k/accelerometer.m;
+
+    %% Save
+    save('./mat/accelerometer_z_axis.mat', 'accelerometer');
+end
+
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+

Author: Dehaeze Thomas

-

Created: 2020-01-27 lun. 17:41

+

Created: 2020-01-28 mar. 17:37

diff --git a/simscape-model.org b/simscape-model.org index a1f2556..b79c9ec 100644 --- a/simscape-model.org +++ b/simscape-model.org @@ -20,3 +20,103 @@ #+PROPERTY: header-args:matlab+ :output-dir figs :END: +* Introduction :ignore: + +* Parameters used for the Simscape Model + +* Simulation Configuration - Configuration reference +As multiple simulink files will be used for simulation and tests, it is very useful to determine good simulation configuration that will be shared among all the simulink files. + +This is done using something called "Configuration Reference" ([[https://fr.mathworks.com/help/simulink/ug/more-about-configuration-references.html][documentation]]). + +Basically, the configuration is stored in a mat file =conf_simscape.mat= and then loaded in the workspace for it to be accessible to all the simulink models. +It is automatically loaded when the Simulink project is open. It can be loaded manually with the command: +#+begin_src matlab :eval no + load('mat/conf_simscape.mat'); +#+end_src + +It is however possible to modify specific parameters just for one Simulink file using the =set_param= command: +#+begin_src matlab :eval no + set_param(conf_simscape, 'StopTime', 1); +#+end_src + +* Subsystem Reference +Several Stewart platform models are used, for instance one is use to study the dynamics while the other is used to apply active damping techniques. + +However, all the Simscape models share some subsystems using the *Subsystem Reference* Simulink block ([[https://fr.mathworks.com/help/simulink/ug/referenced-subsystem-1.html][documentation]]). + +These shared subsystems are: +- =Fixed_Based.slx= - Fixed base of the Stewart Platform +- =Mobile_Platform.slx= - Mobile platform of the Stewart Platform +- =stewart_strut.slx= - One strut containing two spherical/universal joints, the actuator as well as the included sensors. A parameter =i= is initialized to determine what it the "number" of the strut. + +These subsystems are referenced from another subsystem called =Stewart_Platform.slx=, that basically connect them correctly. +This subsystem is then referenced in other simulink models for various purposes. + +* Basic configuration for the Fixed base, Mobile Platform and Struts + +* Sensors included in the Struts and on the Mobile Platform + +* Inertial Sensors +** Z-Axis Geophone +:PROPERTIES: +:header-args:matlab+: :tangle ./src/initializeZAxisGeophone.m +:header-args:matlab+: :comments none :mkdirp yes :eval no +:END: +<> + +This Matlab function is accessible [[file:../src/initializeZAxisGeophone.m][here]]. + +#+begin_src matlab + function [geophone] = initializeZAxisGeophone(args) + arguments + args.mass (1,1) double {mustBeNumeric, mustBePositive} = 1e-3 % [kg] + args.freq (1,1) double {mustBeNumeric, mustBePositive} = 1 % [Hz] + end + + %% + geophone.m = args.mass; + + %% The Stiffness is set to have the damping resonance frequency + geophone.k = geophone.m * (2*pi*args.freq)^2; + + %% We set the damping value to have critical damping + geophone.c = 2*sqrt(geophone.m * geophone.k); + + %% Save + save('./mat/geophone_z_axis.mat', 'geophone'); + end +#+end_src + +** Z-Axis Accelerometer +:PROPERTIES: +:header-args:matlab+: :tangle ./src/initializeZAxisAccelerometer.m +:header-args:matlab+: :comments none :mkdirp yes :eval no +:END: +<> + +This Matlab function is accessible [[file:../src/initializeZAxisAccelerometer.m][here]]. + +#+begin_src matlab + function [accelerometer] = initializeZAxisAccelerometer(args) + arguments + args.mass (1,1) double {mustBeNumeric, mustBePositive} = 1e-3 % [kg] + args.freq (1,1) double {mustBeNumeric, mustBePositive} = 5e3 % [Hz] + end + + %% + accelerometer.m = args.mass; + + %% The Stiffness is set to have the damping resonance frequency + accelerometer.k = accelerometer.m * (2*pi*args.freq)^2; + + %% We set the damping value to have critical damping + accelerometer.c = 2*sqrt(accelerometer.m * accelerometer.k); + + %% Gain correction of the accelerometer to have a unity gain until the resonance + accelerometer.gain = -accelerometer.k/accelerometer.m; + + %% Save + save('./mat/accelerometer_z_axis.mat', 'accelerometer'); + end +#+end_src