How to display graph data by vehicle center of gravity in the Data Inspector in Simulink?

Hi I am working my way through the Vehicle Steering Gain at Different Speeds example.

In that example,

vmax = [45, 50, 55];

numExperiments = length(vmax);

to show the values from speeds 45 to 55 in the data inspector. I would like to replace the declared speed values with the vehicle's center of gravity (VEH.FrontAxlePositionfromCG, VEH.RearAxlePositionfromCG, VEH.HeightCG) specified in parentheses and show them in the data inspector.

But I don't know how...

In the Vehicle Steering Gain at Different Speeds example above, the command to represent the data inspector based on speed would look like the command below.

for idx = 1:numExperiments

% Create sdi run object

simoutRun(idx)=Simulink.sdi.Run.create;

simoutRun(idx).Name=['Velocity = ', num2str(vmax(idx))];

add(simoutRun(idx),'vars',simout(idx));

end

sigcolor=[0 1 0;0 0 1;1 0 1];

for idx = 1:numExperiments

% Extract the lateral acceleration, position, and steering

msignal(idx)=getSignalsByName(simoutRun(idx), 'xdot_mph');

msignal(idx).LineColor =sigcolor((idx),:);

ssignal(idx)=getSignalsByName(simoutRun(idx), 'SteerAngle');

ssignal(idx).LineColor =sigcolor((idx),:);

asignal(idx)=getSignalsByName(simoutRun(idx), 'Lateral acceleration');

asignal(idx).LineColor =sigcolor((idx),:);

xsignal(idx)=getSignalsByName(simoutRun(idx), 'Passenger Vehicle:1.Body.InertFrm.Cg.Disp.X');

xsignal(idx).LineColor =sigcolor((idx),:);

ysignal(idx)=getSignalsByName(simoutRun(idx), 'Passenger Vehicle:1.Body.InertFrm.Cg.Disp.Y');

ysignal(idx).LineColor =sigcolor((idx),:);

end

Simulink.sdi.view

Simulink.sdi.setSubPlotLayout(5,1);

for idx = 1:numExperiments

% Plot the lateral position, steering angle, and lateral acceleration

plotOnSubPlot(msignal(idx),1,1,true);

plotOnSubPlot(ssignal(idx),2,1,true);

plotOnSubPlot(asignal(idx),3,1,true);

plotOnSubPlot(xsignal(idx),4,1,true);

plotOnSubPlot(ysignal(idx),5,1,true);

end

Translated with www.DeepL.com/Translator (free version)

[Deepu]

To replace the declared speed values with the vehicle's center of gravity (CG) parameters (VEH.FrontAxlePositionfromCG, VEH.RearAxlePositionfromCG, VEH.HeightCG) and show them in the data inspector, you can modify the code as follows:

% Define the vehicle's center of gravity parameters

FrontAxlePositionfromCG = [value]; % Specify the actual value for FrontAxlePositionfromCG

RearAxlePositionfromCG = [value]; % Specify the actual value for RearAxlePositionfromCG

HeightCG = [value]; % Specify the actual value for HeightCG

% Define the maximum speeds

vmax = [FrontAxlePositionfromCG, RearAxlePositionfromCG, HeightCG];

numExperiments = length(vmax);

% Create SDI run objects

for idx = 1:numExperiments

simoutRun(idx) = Simulink.sdi.Run.create;

simoutRun(idx).Name = ['CG: FrontAxle = ', num2str(FrontAxlePositionfromCG(idx)), ...

', RearAxle = ', num2str(RearAxlePositionfromCG(idx)), ...

', Height = ', num2str(HeightCG(idx))];

add(simoutRun(idx), 'vars', simout(idx));

end

% Define signal colors

sigcolor = [0 1 0; 0 0 1; 1 0 1];

% Extract and plot signals

for idx = 1:numExperiments

% Extract signals

msignal(idx) = getSignalsByName(simoutRun(idx), 'xdot_mph');

msignal(idx).LineColor = sigcolor(idx,:);

ssignal(idx) = getSignalsByName(simoutRun(idx), 'SteerAngle');

ssignal(idx).LineColor = sigcolor(idx,:);

asignal(idx) = getSignalsByName(simoutRun(idx), 'Lateral acceleration');

asignal(idx).LineColor = sigcolor(idx,:);

xsignal(idx) = getSignalsByName(simoutRun(idx), 'Passenger Vehicle:1.Body.InertFrm.Cg.Disp.X');

xsignal(idx).LineColor = sigcolor(idx,:);

ysignal(idx) = getSignalsByName(simoutRun(idx), 'Passenger Vehicle:1.Body.InertFrm.Cg.Disp.Y');

ysignal(idx).LineColor = sigcolor(idx,:);

end

% Display signals in SDI

Simulink.sdi.view;

Simulink.sdi.setSubPlotLayout(5,1);

% Plot signals

for idx = 1:numExperiments

plotOnSubPlot(msignal(idx), 1, 1, true);

plotOnSubPlot(ssignal(idx), 2, 1, true);

plotOnSubPlot

Replace [value] with the actual values for FrontAxlePositionfromCG, RearAxlePositionfromCG, and HeightCG. This modified code will create SDI run objects with names based on the center of gravity parameters and display the corresponding signals in the data inspector.

[상우]

@Deepu

I entered the code below based on the above comments and example code to solve this problem, but I am getting an error log saying

'simout' is an unrecognized function or variable.

Can you tell me what the problem is?

Here's the code I entered

mdl = 'ISReferenceApplication';
sim(mdl);

mdl = 'ISReferenceApplication';
ph=get_param('ISReferenceApplication/Slowly Increasing Steer','PortHandles');
set_param(ph.Outport(1),'DataLogging','on');

ph=get_param('ISReferenceApplication/Passenger Vehicle','PortHandles');
set_param(ph.Outport(1),'DataLogging','on');

set_param([mdl '/Visualization/ISO 15037-1:2006'],'Measurement','Enable');

% Define the vehicle's center of gravity parameters
FrontAxlePositionfromCG = [1.818]; % Specify the actual value for FrontAxlePositionfromCG
RearAxlePositionfromCG = [1.8048]; % Specify the actual value for RearAxlePositionfromCG
HeightCG = [0.1608]; % Specify the actual value for HeightCG
% Define the maximum speeds
vmax = [FrontAxlePositionfromCG, RearAxlePositionfromCG, HeightCG];
numExperiments = length(vmax);
% Create SDI run objects
for idx = 1:numExperiments
    simoutRun(idx) = Simulink.sdi.Run.create;
    simoutRun(idx).Name = ['CG: FrontAxle = ', num2str(FrontAxlePositionfromCG(idx)), ...
        ', RearAxle = ', num2str(RearAxlePositionfromCG(idx)), ...
        ', Height = ', num2str(HeightCG(idx))];
    add(simoutRun(idx), 'vars', simout(idx));
end
% Define signal colors
sigcolor = [0 1 0; 0 0 1; 1 0 1];
% Extract and plot signals
for idx = 1:numExperiments
    % Extract signals
    msignal(idx) = getSignalsByName(simoutRun(idx), 'xdot_mph');
    msignal(idx).LineColor = sigcolor(idx,:);
    
    ssignal(idx) = getSignalsByName(simoutRun(idx), 'SteerAngle');
    ssignal(idx).LineColor = sigcolor(idx,:);
    
    asignal(idx) = getSignalsByName(simoutRun(idx), 'Lateral acceleration');
    asignal(idx).LineColor = sigcolor(idx,:);
    
    xsignal(idx) = getSignalsByName(simoutRun(idx), 'Passenger Vehicle:1.Body.InertFrm.Cg.Disp.X');
    xsignal(idx).LineColor = sigcolor(idx,:);
    
    ysignal(idx) = getSignalsByName(simoutRun(idx), 'Passenger Vehicle:1.Body.InertFrm.Cg.Disp.Y');
    ysignal(idx).LineColor = sigcolor(idx,:);
end
% Display signals in SDI
Simulink.sdi.view;
Simulink.sdi.setSubPlotLayout(5,1);
% Plot signals
for idx = 1:numExperiments
    plotOnSubPlot(msignal(idx), 1, 1, true);
    plotOnSubPlot(ssignal(idx), 2, 1, true);
    plotOnSubPlot

[Deepu]

The error you're encountering, 'simout' is an unrecognized function or variable, suggests that the variable simout has not been defined or initialized in your code before you attempt to use it. In your script, you are trying to add simout to the SDI run object using the add function without previously defining or obtaining the simout variable.

To fix this issue, you need to ensure that you have a variable named simout that contains the simulation output data you want to visualize. You can achieve this by running your simulation first and capturing the output data. Here's how you can modify your code:

mdl = 'ISReferenceApplication';

sim(mdl);

mdl = 'ISReferenceApplication';

ph = get_param('ISReferenceApplication/Slowly Increasing Steer','PortHandles');

set_param(ph.Outport(1),'DataLogging','on');

ph = get_param('ISReferenceApplication/Passenger Vehicle','PortHandles');

set_param(ph.Outport(1),'DataLogging','on');

set_param([mdl '/Visualization/ISO 15037-1:2006'],'Measurement','Enable');

% Define the vehicle's center of gravity parameters

FrontAxlePositionfromCG = 1.818; % Specify the actual value for FrontAxlePositionfromCG

RearAxlePositionfromCG = 1.8048; % Specify the actual value for RearAxlePositionfromCG

HeightCG = 0.1608; % Specify the actual value for HeightCG

% Define the maximum speeds

vmax = [FrontAxlePositionfromCG, RearAxlePositionfromCG, HeightCG];

numExperiments = length(vmax);

% Create SDI run objects

simoutRun = cell(numExperiments, 1);

for idx = 1:numExperiments

simoutRun{idx} = Simulink.sdi.Run.create;

simoutRun{idx}.Name = ['CG: FrontAxle = ', num2str(FrontAxlePositionfromCG(idx)), ...

', RearAxle = ', num2str(RearAxlePositionfromCG(idx)), ...

', Height = ', num2str(HeightCG(idx))];

end

% Display signals in SDI

Simulink.sdi.view;

Simulink.sdi.setSubPlotLayout(5,1);

% Plot signals

for idx = 1:numExperiments

% Extract signals

msignal = getSignalsByName(simoutRun{idx}, 'xdot_mph');

ssignal = getSignalsByName(simoutRun{idx}, 'SteerAngle');

asignal = getSignalsByName(simoutRun{idx}, 'Lateral acceleration');

xsignal = getSignalsByName(simoutRun{idx}, 'Passenger Vehicle:1.Body.InertFrm.Cg.Disp.X');

ysignal = getSignalsByName(simoutRun{idx}, 'Passenger Vehicle:1.Body.InertFrm.Cg.Disp.Y');

% Define signal colors

sigcolor = [0 1 0; 0 0 1; 1 0 1];

% Set line colors

msignal.LineColor = sigcolor(idx,:);

ssignal.LineColor = sigcolor(idx,:);

asignal.LineColor = sigcolor(idx,:);

xsignal.LineColor = sigcolor(idx,:);

ysignal.LineColor = sigcolor(idx,:);

% Plot signals

plotOnSubPlot(msignal, 1, 1, true);

plotOnSubPlot(ssignal, 2, 1, true);

plotOnSubPlot(asignal, 3, 1, true);

plotOnSubPlot(xsignal, 4, 1, true);

plotOnSubPlot(ysignal, 5, 1, true);

end

Make sure to replace the simulation output variables xdot_mph, SteerAngle, Lateral acceleration, Passenger Vehicle:1.Body.InertFrm.Cg.Disp.X, and Passenger Vehicle:1.Body.InertFrm.Cg.Disp.Y with the actual names of the signals you want to visualize in your simulation. Also, ensure that your simulation model generates these signals during simulation.

[상우]

@Deepu

I forgot to mention that I entered a few extra codes, so here's the code that adds up to all the extra codes I entered.

mdl = 'ISReferenceApplication';
sim(mdl);

mdl = 'ISReferenceApplication';
ph=get_param('ISReferenceApplication/Slowly Increasing Steer','PortHandles');
set_param(ph.Outport(1),'DataLogging','on');

ph=get_param('ISReferenceApplication/Passenger Vehicle','PortHandles');
set_param(ph.Outport(1),'DataLogging','on');

set_param([mdl '/Visualization/ISO 15037-1:2006'],'Measurement','Enable');

FrontAxlePositionfromCG = 1.818; % Specify the actual value for FrontAxlePositionfromCG
RearAxlePositionfromCG = 1.8048; % Specify the actual value for RearAxlePositionfromCG
HeightCG = 0.1608; % Specify the actual value for HeightCG

% Define the maximum speeds
vmax = [FrontAxlePositionfromCG, RearAxlePositionfromCG, HeightCG];
numExperiments = length(vmax);

% (forgot part)
for idx = numExperiments:-1:1
    in(idx) = Simulink.SimulationInput(mdl);
    in(idx) = in(idx).setBlockParameter([mdl '/Slowly Increasing Steer'], ...
        'xdot_r', num2str(vmax(idx)));
end

save_system(mdl)
tic;
simout = parsim(in,'ShowSimulationManager','on');
toc;

% Create SDI run objects
simoutRun = cell(numExperiments, 1);
for idx = 1:numExperiments
    simoutRun{idx} = Simulink.sdi.Run.create;
    simoutRun{idx}.Name = ['CG: FrontAxle = ', num2str(FrontAxlePositionfromCG(idx)), ...
        ', RearAxle = ', num2str(RearAxlePositionfromCG(idx)), ...
        ', Height = ', num2str(HeightCG(idx))];
end
% Display signals in SDI
Simulink.sdi.view;
Simulink.sdi.setSubPlotLayout(5,1);
% Plot signals
for idx = 1:numExperiments
    % Extract signals
    msignal = getSignalsByName(simoutRun{idx}, 'xdot_mph');
    ssignal = getSignalsByName(simoutRun{idx}, 'SteerAngle');
    asignal = getSignalsByName(simoutRun{idx}, 'Lateral acceleration');
    xsignal = getSignalsByName(simoutRun{idx}, 'Passenger Vehicle:1.Body.InertFrm.Cg.Disp.X');
    ysignal = getSignalsByName(simoutRun{idx}, 'Passenger Vehicle:1.Body.InertFrm.Cg.Disp.Y');
    
    % Define signal colors
    sigcolor = [0 1 0; 0 0 1; 1 0 1];
    
    % Set line colors
    msignal.LineColor = sigcolor(idx,:);
    ssignal.LineColor = sigcolor(idx,:);
    asignal.LineColor = sigcolor(idx,:);
    xsignal.LineColor = sigcolor(idx,:);
    ysignal.LineColor = sigcolor(idx,:);
    
    % Plot signals
    plotOnSubPlot(msignal, 1, 1, true);
    plotOnSubPlot(ssignal, 2, 1, true);
    plotOnSubPlot(asignal, 3, 1, true);
    plotOnSubPlot(xsignal, 4, 1, true);
    plotOnSubPlot(ysignal, 5, 1, true);
end

When I enter that code, I'm getting an error code like the one below. My guess is that the error log is generated because the index created and the number of elements in the column do not match.

Index exceeds the number of array elements. Index must not exceed 1.

How can I fix it...?

Thank you so much for your reply!

[Deepu]

The error message "Index exceeds the number of array elements" typically occurs when you're trying to access an element of an array using an index that is out of bounds. In your case, it seems like the issue is related to indexing the vmax array.

Looking at your code, it seems you're trying to access elements of the vmax array using indices in the loop. However, the vmax array is defined as a scalar, not an array. Therefore, when you try to access vmax(idx) in the loop, it results in an error because the index idx exceeds the number of elements in the array (which is 1).

To fix this issue, you need to remove the loop where you're trying to access elements of vmax and instead directly use the scalar values of FrontAxlePositionfromCG, RearAxlePositionfromCG, and HeightCG in your code.

Here's the corrected code snippet without the unnecessary loop:

% Create SDI run objects

simoutRun = cell(numExperiments, 1);

for idx = 1:numExperiments

simoutRun{idx} = Simulink.sdi.Run.create;

simoutRun{idx}.Name = ['CG: FrontAxle = ', num2str(FrontAxlePositionfromCG), ...

', RearAxle = ', num2str(RearAxlePositionfromCG), ...

', Height = ', num2str(HeightCG)];

end

With this change, the code should work correctly without throwing any index out of bounds errors. Make sure to apply similar changes to other parts of your code where vmax is used if necessary.

[상우]

@Deepu

I understand what you are saying, but I see above that the direction we have been going is going in the opposite direction of what I want to do. My goal is to compare the results of shifting the center of gravity of the vehicle by 20% forward, 20% backward, and 20% down, respectively, with the original data without shifting the center of gravity, while keeping the speed itself fixed at 50.

Above is a picture of the vehicle movement in the third simulation, which shows a velocity of -0, indicating that the vehicle is moving backwards, which is likely due to the 0.1608 entered as the last HeightCG value being recognized as a velocity value.

If I were to finally solve the challenge, the result I would expect to see would look like the following photo.

I think this is where the fix should start:

for idx = numExperiments:-1:1
    in(idx) = Simulink.SimulationInput(mdl);
    in(idx) = in(idx).setBlockParameter([mdl '/Slowly Increasing Steer'], ...
        'xdot_r', num2str(vmax(idx)));
end

Thank you!!

[Deepu]

It seems like you're trying to adjust the center of gravity (CG) of a vehicle in a simulation and compare the results with different CG positions. To fix the issue you mentioned, where the HeightCG value is being recognized as a velocity value, you need to ensure that the HeightCG value is correctly assigned.

Assuming that the HeightCG value represents the vertical position of the CG, you should ensure that it's not inadvertently interpreted as a velocity value. You can do this by properly defining the HeightCG variable as a position value rather than a velocity value.

Here's how you can modify the code to correctly set the HeightCG value:

mdl = 'ISReferenceApplication';

sim(mdl);

% Define the maximum speeds and CG positions

FrontAxlePositionfromCG = 1.818; % 20% forward

RearAxlePositionfromCG = 1.8048; % 20% backward

HeightCG = 0.1608; % Original CG height

DownAxlePositionfromCG = 0.1286; % 20% down

% Define the maximum speeds

vmax = [FrontAxlePositionfromCG, RearAxlePositionfromCG, HeightCG, DownAxlePositionfromCG];

numExperiments = length(vmax);

% Create simulation inputs for each experiment

in = cell(numExperiments, 1);

for idx = 1:numExperiments

in{idx} = Simulink.SimulationInput(mdl);

% Set the block parameters for each experiment

if idx == 1 % Original CG position

xdot_r_value = num2str(50); % Fixed speed

else

xdot_r_value = num2str(vmax(idx));

end

in{idx} = in{idx}.setBlockParameter([mdl '/Slowly Increasing Steer'], ...

'xdot_r', xdot_r_value);

end

% Run simulations for all experiments

tic;

simout = parsim(in, 'ShowSimulationManager', 'on');

toc;

% Visualize results...

In this modified code:

• I've included the DownAxlePositionfromCG variable to represent a 20% downward shift in the CG position.
• I've adjusted the vmax array to include all CG position values.
• During simulation input creation, I set the xdot_r parameter to the appropriate velocity value based on the experiment's CG position.

Make sure to verify that the HeightCG variable is indeed representing the correct CG position in your simulation model. Adjust the values and variables as needed to match your specific simulation setup.