I have two state space models, one 5th order and another one 4th order, which I want to use in series in a Simulink model. However, I would like to read the (A,B,C,D,x0) parameters of each model from a file. This would have to be done in Simulink. Then I process each input, update the states, and compute an output. The inputs also have to be read from a file. Does anyone know how to do this? Any help will be appreciated. Thanks
No, they are the result of a system identification task done off-line. We need to hook this up to a PID controller using a Texas Instrument microcontroller. We're hoping to build a Simulink model for the two state space models in tandem, then use the code generator to get the C code and merge it with the C
code in the microcontroller. The first state space model is a low pass filter, then the second state space model is a Kalman filter. So we first need to read the model parameters from a file, then start processing data with the models, each time reading the inputs and outputs from another file (different from the file for the parameters). I hope this helps. Thanks for your reply.
Jose
Dear Mr. Ramos,
As the parameter identification is done off-line you asume the parameters of the systems are constant. So A, B, C and D as well as x0 are known at the beginning and don't change over time. Then you can easily write a start-up script (Model Workspace or Initialize Function) using the suitable commands, e.g.fscan or fread, depending on the file format.
When it comes to the inputs, the question is again: Are all inputs for the whole processing time available at the beginning? Simulink can read files directly but needs an relation between data and time. Otherwise, you may try using a Matlab Function to program the read from file procedure, but I don't have any experiences here. But if you do it like this, you have to care about the correct relation of data and time by yourself.
Dear Martin:
Thanks for your answer. I'll certainly look into this. The ultimate goal is to get the C code so that it operates the same way in the controller.
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