how to find parameters (A and B ) for a non linear arx model and how can i convert this non linear arx model into transfer function

for finding parameters in non linear arx model and converting it to transfer function

Answer 1

[Rajiv Singh]

"Converting" a nonlinear model into a linear one is an exercise in linearization. See idnlarx/linearize and idnlarx/linapp functions.

Depending upon the configuration of the nonlinear ARX model, it may employ a linear block (which looks like an ARX model) in parallel to a nonlinear block. If you just want to extract out this linear piece, you can use the "getlinmod" method. See "help idnlarx/getlinmod".