States of the system and linearization

States of the system in Simulink Conttrol Design are identified at the output of the integrator blocks accross the system. Now, if a model is already developed in a discrete state space form, and specifically, intergrators are already implemented in, for example, forwad euler form by simply using memory blocks, how can one "inform" the linearize on what the states fo the system are?

In simple words, how to use linearize for a high order dynamics system that does not contain any Matlab integrator block?

@Ryan G @Rajiv Singh @Arkadiy Turevskiy

Answer 1

[Drew Davis]

Simulink control design's linearize command will pretty much recognize states for all of Simulink's built-in block types/Simscape network states etc.

Now memory blocks need to be configured as follows to be recognized by linearize:

1. The memory block must be driven by a discrete sample time ("Inherit sample time" selected in the block dialog on a discrete signal)
2. The block must be "treated as a unit delay when linearized with discrete sample time"

Note, if the memory block is driven by a continuous sample time signal, linearize WILL not recognize that state.

A slighlty easier approach would be to replace all memory blocks with unit delays, as unit delays are ALWAYS treated as discrete.