How to control MR damper through Matlab program?

Hi all

I made a Matlab script that will calculate how much current I need for controlling a MR damper. Now anybody can help me to figure out how can I feed this value to the hardware i.e. MR damper to pass the required current ?

Thanks in advance.

[Arun Gowda]

can you send me the code please...

[Ahmed Adel]

can you send me the code please...

[Sam Chak]

@Ahmed Adel. What code are you looking for? The control code? Or the MR Damper model written in MATLAB code?

Answer 1

[Walter Roberson]

What does the hardware need to be fed? An output wire with the calculated current? A few bytes of binary data that the hardware will interpret as indicating what current level to use? A plain string containing the decimal expansion of the current level to use? A specific "change current" command such as "CUR" followed by the level?

In any but the direct output wire case, we need to know what the data transport is between the computer and the hardware. True serial port? Parallel port? USB emulating serial port? GPIB? VISA over GPIB over USB? Direct digital signal through a DIO (Digital I/O) board connected to a signal generator ?

In the case of the direct output wire, you will need a DAQ (Digital to Analog). A fair number of those use voltage levels, but some of them can be configured to output current levels. You would probably in that case need to use a National Instruments board and use Mathwork's Instrument Control Toolbox in "session mode" which might require using a 64 bit version of MATLAB.

Answer 2

[Kimbugwe Daniel]

I am having trouble writing a code in MATLAB to control seismic and white noise vibrations of a 20 storey frame structure subjected to LA ground motions using a Tuned Inerter Damper with know masses and stiffnesses . Can anyone help me

[Sam Chak]

Hi @Kimbugwe Daniel

Writing the code is the last thing you do to implement the control algorithm. Have you designed the control equation?

You also need the mathematical models for the following:

• 20-storey frame structure
• LA ground motions
• Tuned Inerter Damper

[Kimbugwe Daniel]

I don’t think I really understand by the mathematical model of the 20 frame storey but I have written code to determine the mode shapes and natural frequencies . Next I need to introduce the LA ground motions into the structure to observe the behavior of the structure without dampers. This I don’t know how . I have equations of motions and frequency response functions of frame structure - Tuned inerter damper system

[Sam Chak]

Hi @Kimbugwe Daniel

I'm not an earthquake expert, but I expect that a 20-storey building structure to have 20 coupled ordinary differential equations (ODEs).

I don't know what LA ground motions are. If they are disturbances to the lateral motion of the first floor (being at ground level), then mathematically, you should inject the LA ground motions (as inputs) to the ODE of the first floor.

By the way, you are advised to post a New Question together with the equations of motion in MATLAB code.

Also provide the math model of LA ground motions. If they are unavailable, then I guess they are in some form of time-series data.

[Kimbugwe Daniel]

ok

[Rishikesh]

@Sam Chak Hi can you help me to design a PID controller for Bouc Wen model of mr damper system

[Sam Chak]

Hi @Rishikesh, I'm unfamiliar with the Bouc–Wen model. But if you post a new question with the mathematical model, maybe I advise something.

[Rishikesh]

Hello @Sam Chak Thank you for your reply and helping me out. This is simulink model for 2 dof system with MR damper. I'm not getting desired output graphs for Forve vs Displacement and Force vs Velocity. Also about the PID controller I'm not aware about how a PID works and what will be the input and what values to be considered for this MR damper model. Please help me if you can. I would really appricitate. Thank You

[Sam Chak]

Hi @Rishikesh

First things first, please open a question and post the mathematical model (ODE) of the Bouc–Wen MR Damper. Without mathematically analyzing the ODE, there is no guarantee that the PID controller would work. From the math equations, please describe about the variable (symbol) that you want to control. By the way, what do M and R stand for? What does the damper do (to dampen some liquid or solid or gas)?

[Rishikesh]

Hello sam

Sorry for the partial information. MR stands for mangnetorehological fluid which is used in MR damper and the MR fluid in damper acts as a liquid possessing properties when provided with a magnetic field depending on the current value it converts in semi solid or solid. The stiffness of the fluid continoulsy varies with the indudced field. PID control is required for us to provided required current to the system