symWriteSSC

Create new Simscape component

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Syntax

symWriteSSC(newComponentName,templateComponentName,eqns)
symWriteSSC(newComponentName,templateComponentName,eqns,Name,Value)

Description

example

symWriteSSC(newComponentName,templateComponentName,eqns) creates a new Simscape™ component newComponentName using an existing component templateComponentName as a template and adding eqns. Thus, the new component has both the existing equations taken from the template component and the added equations.

example

symWriteSSC(newComponentName,templateComponentName,eqns,Name,Value) uses additional options specified by one or more Name,Value pair arguments.

Examples

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Create a new Simscape component by using an existing component as a template and adding an equation.

Suppose you have the Simscape component spring.ssc in your current folder.

type('spring.ssc');
component spring < foundation.mechanical.rotational.branch

parameters
    spr_rate = { 10, 'N*m/rad' };
end

variables
    phi = { value = { 0, 'rad'}, priority = priority.high };
end

function setup
    if spr_rate <= 0
        pm_error('simscape:GreaterThanZero','Spring rate' )
    end
end

equations
    w == phi.der;
    t == spr_rate*phi;
end

end

Create symbolic variables with names of the parameters and variables of the component you are going to use when creating new equations. Also create a symbolic variable, u, to denote the energy of the rotational spring.

syms spr_rate phi u

Create the equation defining the energy u.

eq = u == spr_rate*phi^2/2;

Create the new component, myRotationalSpring.ssc, that is a copy of the component spring.ssc with an additional equation defining the energy of the rotational spring.

symWriteSSC('myRotationalSpring.ssc','spring.ssc',eq)
Warning: Equations contain undeclared variables 'u'. 
> In symWriteSSC (line 94)

symWriteSSC creates the component myRotationalSpring.ssc.

type('myRotationalSpring.ssc');
component myRotationalSpring

parameters
    spr_rate = { 10, 'N*m/rad' };
end

variables
    phi = { value = { 0, 'rad'}, priority = priority.high };
end

function setup
    if spr_rate <= 0
        pm_error('simscape:GreaterThanZero','Spring rate' )
    end
end

equations
    w == phi.der;
    t == spr_rate*phi;
    u == phi^2*spr_rate*(1.0/2.0);
end

end

Create a Simscape component with the title and descriptive text different from those of the template component.

Suppose you have the Simscape component spring.ssc in your current folder. This component does not have any title or descriptive text.

type('spring.ssc');
component spring < foundation.mechanical.rotational.branch

parameters
    spr_rate = { 10, 'N*m/rad' };
end

variables
    phi = { value = { 0, 'rad'}, priority = priority.high };
end

function setup
    if spr_rate <= 0
        pm_error('simscape:GreaterThanZero','Spring rate' )
    end
end

equations
    w == phi.der;
    t == spr_rate*phi;
end

end

Create symbolic variables with names of the parameters and variables of the component you are going to use when creating new equations. Also create a symbolic variable, u, to denote the energy of the rotational spring.

syms spr_rate phi u

Create the equation defining the energy u.

eq = u == spr_rate*phi^2/2;

Create the new component, myRotationalSpring.ssc, based on the spring.ssc component. Add the equation eq, the title “Rotational Spring”, and a few lines of descriptive text to the new component.

symWriteSSC('myRotationalSpring.ssc','spring.ssc',eq,...
'H1Header','% Rotational Spring',...
'HelpText',{'% The block represents an ideal mechanical rotational linear spring.',...
            '% Connections R and C are mechanical rotational conserving ports.'...
            '% The block positive direction is from port R to port C. This means'...
            '% that the torque is positive if it acts in the direction from R to C.'})
Warning: Equations contain undeclared variables 'u'. 
> In symWriteSSC (line 94)

symWriteSSC creates the component myRotationalSpring.ssc.

type('myRotationalSpring.ssc');
component myRotationalSpring
% Rotational Spring
% The block represents an ideal mechanical rotational linear spring.
% Connections R and C are mechanical rotational conserving ports.
% The block positive direction is from port R to port C. This means
% that the torque is positive if it acts in the direction from R to C.

parameters
    spr_rate = { 10, 'N*m/rad' };
end

variables
    phi = { value = { 0, 'rad'}, priority = priority.high };
end

function setup
    if spr_rate <= 0
        pm_error('simscape:GreaterThanZero','Spring rate' )
    end
end

equations
    w == phi.der;
    t == spr_rate*phi;
    u == phi^2*spr_rate*(1.0/2.0);
end

end

Input Arguments

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Name of Simscape component to create, specified as a file name enclosed in single quotes. File must have the extension .ssc. If you do not provide file extension, symWriteSSC assumes it to be .ssc. If you do not specify the absolute path, symWriteSSC creates the new component in the current folder.

Example: 'MyNewComponent.ssc'

Name of template Simscape component, specified as a file name enclosed in single quotes. File must have the extension .ssc. If you do not provide the file extension, symWriteSSC assumes it to be .ssc. The component must be on the MATLAB® path or in the current folder.

Example: 'TemplateComponent.ssc'

Symbolic equations, specified as a row vector.

Example: [ y(t) == diff(x(t), t), m*diff(y(t), t, t) + b*y(t) + k*x(t) == F]

Name-Value Pair Arguments

Specify optional comma-separated pairs of Name,Value arguments. Name is the argument name and Value is the corresponding value. Name must appear inside quotes. You can specify several name and value pair arguments in any order as Name1,Value1,...,NameN,ValueN.

Example: symWriteSSC('myComp.ssc','template.ssc',eq,'H1Header','% New title','HelpText',{'% Description of the','% new component'})

Title specified as a row vector of characters (type char) starting with %. If the first character is not %, then symWriteSSC adds %.

If the template component has a title and you use H1Header, the new component will have the title specified by H1Header. If the template component has a title and you call symWriteSSC without H1Header, the new component will have the same title as the template component.

Example: 'H1Header','% New title'

Descriptive text, specified as a cell array of row vectors of characters. Each row vector must start with %. If the first character is not %, then symWriteSSC adds %.

If the template component has descriptive text and you use HelpText, the new component will have only the text specified by HelpText. In this case, symWriteSSC does not copy the descriptive text of the template component to the new component. If the template component has a title and you call symWriteSSC without HelpText, the new component will have the same descriptive text as the template component.

Example: 'HelpText',{'% Description of the','% new component'}

See Also

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Introduced in R2016a

Symbolic Math Toolbox Documentation

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