Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

I need help with matlab designing a steady state feedback H2 control system

  1. Apr 29, 2017 #1
    Hi everyone.
    I'm designing a steady state feedback H2 control system.
    Actually, my major is tribology and I have no experience in designing control system.
    So it is really big problem for me.
    Anyway, this is my simple model of tribometer which applies normal load on the surface.
    upload_2017-4-30_11-5-40.png upload_2017-4-30_11-19-43.png (is it right??)
    My purpose is control the x (position of m) during the test (change in y) to apply constant normal load (k(x+y) ??) on the surface.
    When I start the test, the normal force will be kx, but during the test the movement of substrate(y) occurs and I want to control the position of x to maintain constant normal load on the substrate.
    And I should design state feedback controller with H2 norm minimized via LMI optimization.
    upload_2017-4-30_11-20-16.png with upload_2017-4-30_11-20-42.png
    First, I thought disturbance (w) is y and output z will be k(x+y)... but I failed.
    I really need some help to design the state feedback controller.
    Last edited by a moderator: Apr 30, 2017
  2. jcsd
  3. Apr 30, 2017 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2017 Award

    It's been awhile for me, but here goes. Let's start with (Net Force) = mass * acceleration, which in your case acceleration is x double dot. So should your first equation equal zero? If you set it equal to the driving force (the force you are applying to keep it at desired position) then that seems what you need to solve. Is gravity acting downward on the mass? If so then you should have that in there as a downward external force on the mass.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted