Initiate array in Simscape

I have an array in my workspace and would like to initiate the values at a particular time step in Simscape. My current Simscape model has a 'from workspace' block where it cycles through the array (and then repeats). However, I only want to initiate these values at t = 10 rather than t = 0. Is there a way to do this?

Answer 1

[Yash]

Hi Zubair,

As I can understand, you want to initialize an array in Simulink only after a specific time has elapsed. There are several approaches you can take, below are some methods you might consider:

1. Prepare the Data in MATLAB Workspace and Configure the "From Workspace" Block accordingly:

• Ensure that your array in the workspace is formatted as a time series or as a matrix where the first column represents time steps, and the subsequent columns represent the data points.
• Modify the time data so that the value changes occur at t = 10. For example, if your original data is a matrix data and you want the change to happen at 10 seconds, you might append a row with the initial value at time 9.999 and the new value at time 10.

% Example of modifying data to change at t = 10
initial_value = ...; % Your initial value before t = 10  
new_values = ...; % Your array of new values to introduce at t = 10   
data = [0, initial_value; % Before t = 10
9.999, initial_value; % Just before the change
10, new_values(1, :); % New values introduced at t = 10
11, new_values(1, :); % Values constant after t = 10
... % Rest of your time-value pairs
];

• Open the block parameters and ensure that the data is correctly formatted for the block's expectations (e.g., as a structure with time, signals, and possibly dimensions fields, or as a matrix).
• Make sure the "Interpolate data" option is selected if you want a smooth transition between the data points.

2. Use an Enabled Subsystem:

• If you want to ensure that the data is not read until t = 10, you can use an Enabled Subsystem that contains the "From Workspace" block.
• Create an enable signal that becomes true at t = 10. This can be done using a "Step" block with the Step time set to 10 seconds.
• Connect the enable signal to the Enabled Subsystem.

3. Use the "Step" block:

• If you want the signal values to become zero before t=10 and and values from workspace after that, you can use a "Step" block.
• Use a "Product" block with the "Step" block and the 'From Workspace" block as inputs and you will get the desired results.

Hope this helps!