How to store all the sequential signals generated during the Simscape simulation in Simulink and access those signals inside the function block?

I have a Simscape-based simulation model, and my goal is to integrate a Reinforcement Learning agent that controls the existing inverters in my model. To achieve this, the RL agent requires measurement signals from time (t-k) to t, where k represents a sliding window of a particular size. Unfortunately, I am encountering issues in implementing this functionality to store the sequential measurements and access the required window of measurements to provide them as observations to the RL agent. I would be grateful for any assistance in this matter.

[Emmanouil Tzorakoleftherakis]

How long is k? Would using delay blocks work?

[Bipin Paudel]

Generally, the value of k can range from 20. Can we use a single delay block for this value of k? I am under the impression that if I use a delay block, I have to use k different delay blocks. Are there any other solutions?

Answer 1

[Fangjun Jiang]

The "Buffer" block?

https://www.mathworks.com/help/dsp/ref/buffer.html

[Bipin Paudel]

I have a Simscape-based model with a solver as ode1 (Euler) in model configurations. I got an error while using Buffer that says, "all sample times must be discrete. No continuous or constant sample times are allowed". However, I cannot change my solver parameter to be discrete because, in that case, the simulation will not run.

[Fangjun Jiang]

I did the following on the "f14" example model, which runs on variable-step ode45.

Insert a 'Signal Specification' block between the signal and the Buffer block and specify a sample time.