How to set parameters of Recursive Polynomial Model Estimator in Simulink

Hello! everyone,

I have a question when using the Recursive Polynomial Model Estimator. I am trying to achieve the online estimation of a two-input two-output system. So my settings are na: [2,2;2,2], nb: [1,1;1,1]; nk: [1,1;1,1]. But there is an error that shows the number of parameters in na must be a scalar. Why is there such an error? How to fix it?

Thanks.

Answer 1

[Rajiv Singh]

The Recursive Polynomial Model Estimator supports single output estimations only.

[Ziyang Zhang]

Thank you very much. Is there any toolbox for the online estimation of MIMO system in Simulink?

[Rajiv Singh]

I can't speak to the entire family of products but if you do not care for recursive estimation, a possible approach using System Identification Toolbox is as follows:

1. Collect data (either time-domain signals, or frestimate results; the latter requires Simulink Control Design) from your model.
2. Perform offline estimation in MATLAB using commands such as ssest and tfest.

[Ziyang Zhang]

Thanks for your kind reply. But I want to online estimate system model and implement adaptive MPC for the two-input two-output system. It seems I can't make it using Simulink.

[Rajiv Singh]

The recursive estimation features are limited right now and we plan to remove I/O size limitations in future. Right now, one possibility is to use a different estimator for each output. If you have multiple inputs too, you can only use the ARX recursive estimator.

[Ziyang Zhang]

Thanks for your information.