multi input system identification

Hello

I have some data for a multi input and one output system. In different time period i apply different input to system and get output.

for exmple for 10 second input pressure is 1 and temperture is 300 and next 10 second pressure is 1.5 and temperature is 300.

I made these inputs as a vector and I tried idnlgrey command but this function use this vector as time series but in fact there is no relation between inputs and time.

what is right method to create inputs vector?

and how can I identify this system with multiple inputs?

note i'm using idnlgrey and pem command.

[Walter Roberson]

idnlgrey command but this function use this vector as time series but in fact there is no relation between inputs and time.

??? In the previous paragraph you wrote,

for exmple for 10 second input pressure is 1 and temperture is 300 and next 10 second pressure is 1.5 and temperature is 300.

That means for time 0 to time 10 the input pressure is 1 and temperature is 300, and that time 10 to 20 that pressure is 1.5 and temperature is 300. You just told us the relationship between the inputs and time: time 0 to 10 has one set of values time 10 to 20 has a different set of values. Those 0 and 10 and 20 times are all that is needed to establish a relationship between inputs and time.

[Shayan Goli]

let me explain more

I mean there is no relationship between input and time in the system formula.

There is no time-based parameter in the system formul.

in addition I applied different pressure in 10 seconds period but in fact you may apply different pressure evrey second so in both situation out should be same.

Were my explanations clear and sufficient?

[Walter Roberson]

I am not certain, but I think you might be saying that for your purposes the system does not evolve in time? That even though obviously the system takes finite time to alter in response to a pressure change, that you are not concerned about that change process, and are only concerned about what it settles to in response to pressure changes?