MATLAB Answers

How to find steady-state Operating point for a vehicle model built using Simscape?

1 view (last 30 days)
Sajad  A.Anbaran
Sajad A.Anbaran on 4 May 2018
Commented: Sajad A.Anbaran on 23 Oct 2019
What I essentially try to do is to control ICE speed with a PI controller. the model is attached to this message.
Below is the workflow that I follow:
  1. find model steady-state operating point
  2. linearize at operating point.
  3. validate linearization with Frequency Response Estimation
  4. everything good? then continue with PI tuning using Control system Toolbox.
for step 1 and 2 I use Linear Analaysis "trim model" from operating point drop-down. then specify states/known/constrains. once, trimming is done, I get Bode plot from Linear Analysis Tool.
In the trim window, there are several variables that I don't know what to do with them. They are highlighted in picture below
Question 1) What do highlighted variables represent?
Question 2) What should be the variables specifications as state/known/constrains?
To my understanding, I selected engine speed and vehicle speeds as state variables since I want to design Engine speed controller. Correct me if I am wrong.
Question 3) How to handle linearization and operating point search for a Simscape model? MATLAB help recommends "projection-based trim optimizers" to produce better ttrimming results for simscape models.
There are few optimization methods. I don't know which to select and what should be the "optimization option" setting.
Thank you, Sajad

Answers (1)

Veer Alakshendra
Veer Alakshendra on 17 May 2018
  1 Comment
Sajad  A.Anbaran
Sajad A.Anbaran on 23 May 2018
Thank you Veer, I already watched the video.I followed the instruction in the video. I selected Engine speed and vehicle speed as state variables because I intend to control engine speed. However, trimming was not successful.
Could you please tell me where I am doing wrong?
And is it necessary to have multi-speed transmission to be able to design vehicle speed control? the control goal is "reference tracking".
Thank you,
Viyan (Sajad)

Sign in to comment.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!