Algebraic Loop Error and does not linearization

Doga Selcuk

2022 1 17

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6 次查看（30 天）

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Hello everyone, i'm working on (Control Tutorials for MATLAB and Simulink - Inverted Pendulum: Simulink Modeling (umich.edu)) Inverted pendulum modelling, however in 2021 version Matlab does not have "fcn" function so i tried to fix this problem by using matlab function. Now i can not have the graph and linearization cause i always have the same error which is Algebraic loop error with 'untitled1/Subsystem/MATLAB Function'. I'll try to explain what i have done

1) I created integrators and function blocks etc.

2) I used Mux for 4 functions as in the link given above.

3) I coded functions in those block.

4) When i connected them with muxes i followed muxed input numbers and my code values.

5)I cretaed subsystem. Add scope and trim it.

I need to linearization and see graphs but i can't.

function y = fcn(u)
m=0.01;
l=0.3;
y =m*(u(1)-l*u(2)^2*sin(u(3))+l*u(4)*cos(u(3)));
%This is for N value.
%Codes Errors:
Index expression out of bounds. Attempted to access element 2. The valid range is 1-1.
More information
Function 'Subsystem/MATLAB Function' (#55.53.54), line 4, column 20:
"2"
Launch diagnostic report.
Component:MATLAB Function | Category:Coder error
Errors occurred during parsing of MATLAB function 'untitled1/Subsystem/MATLAB Function'
Component:MATLAB Function | Category:Coder error
Simulink cannot determine sizes and/or types of the outputs for block 'untitled1/Subsystem/MATLAB Function' due to errors in the block body, or limitations of the underlying analysis. The errors might be inaccurate. Fix the indicated errors, or explicitly specify sizes and/or types for all block outputs.
Component:MATLAB Function | Category:Coder error
Cannot solve algebraic loop involving 'untitled1/Subsystem/P' because it consists of blocks that cannot be assigned algebraic variables, such as blocks with discrete-valued outputs, blocks with non-double or complex outputs, Stateflow blocks, or nonvirtual subsystems. Consider breaking the algebraic loop. For example, add a delay or a memory block to the loop. To see more details about the loops use the command Simulink.BlockDiagram.getAlgebraicLoops(bdroot) 
Component:Simulink | Category:Model error
Algebraic loop error with 'untitled1/Subsystem/MATLAB Function3'
Component:Simulink | Category:Model error
Algebraic loop error with 'untitled1/Subsystem/N'
Component:Simulink | Category:Model error
Algebraic loop error with 'untitled1/Subsystem/MATLAB Function'
Component:Simulink | Category:Model error
Algebraic loop error with 'untitled1/Subsystem/P'