Predict block did not update

Hi!

I am learning thi Imitate MPC example https://www.mathworks.com/help/reinforcement-learning/ug/imitate-mpc-controller-for-lane-keeping-assist.html and apply it in Simulink. I am using Predict block to run the trained dlNetwork in Simulink. However, the output of the Predict block is not updated for every time step. The output stays constant throughout simulation. Can someone help me with this?

Thank you!

[Gayathri]

Hello, Can you please share your simulink model.

[Saskia Putri]

Hi,

Attached is the simulink file along with the trained model from https://www.mathworks.com/help/reinforcement-learning/ug/imitate-mpc-controller-for-lane-keeping-assist.html. Thank you.

Answer 1

[Gayathri]

Hello @Saskia Putri,

I understand that you are trying to model the “MPC” example in Simulink and the output of “predict” block in the model is not updating. I also faced a similar issue.

The output of “state space” block in Simulink does not produce the desired result as required in the example, which is to calculate “A*xk + B*[uk; Vx*rho]”.

Instead, it is better to model this equation manually using “matrix multiplication” and “adder”. You can model the same as shown below.

You can find more information about “state-space” block in the following link,

https://in.mathworks.com/help/simulink/slref/discretestatespace.html

Also, in the “AI control” part of the model, I think the constant which goes as input to the “predict” block must be “rho” instead of “Vx”.

For more information about the example, please refer to the below link.

https://www.mathworks.com/help/releases/R2024a/reinforcement-learning/ug/imitate-mpc-controller-for-lane-keeping-assist.html

Hope you find this information helpful.