# NTNUJAVA Virtual Physics LaboratoryEnjoy the fun of physics with simulations! Backup site http://enjoy.phy.ntnu.edu.tw/ntnujava/

## Information about this web site => Request for physics Simulations => Topic started by: cruels on June 12, 2011, 04:57:14 pm

 Title: Magnetic levitation model 2 Post by: cruels on June 12, 2011, 04:57:14 pm HelloI need to create a model of Magnetic levitation. I read the post at http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1683.0 but modification of this simulation is too hard for me. Could anyone help me? I attach my equations Title: Re: Magnetic levitation model 2 Post by: Fu-Kwun Hwang on June 15, 2011, 02:01:53 pm What are the meaning of x1,x3,x4? x1 in the range of [0,0.016]? Do you mean x1 can be zero???Do you mean EM1,EM2 and magnet ball are all movable?Please explain in more detail. Title: Re: Magnetic levitation model 2 Post by: cruels on June 15, 2011, 09:00:51 pm Thank you for your replyx1 position of the ball - 0 when the ball touches EM1, 0.016 when the ball touches EM2 - unit [meter]x2 velocity - unit [meter per second]x3 current in EM1 - unit [Ampere]x4 current in EM2 - unit [Ampere]Only magnet ball is movable Title: Re: Magnetic levitation model 2 Post by: Fu-Kwun Hwang on June 15, 2011, 10:42:27 pm You need to set up initial conditions for your case: initial value for x1, x3,x4 etc. What you need to do is translate those equation into EJS and add view elements for your case.Try to do it with EJS, and write down where you do know what to do next.Upload your ejs source and we will try to help you. Title: Re: Magnetic levitation model 2 Post by: cruels on June 24, 2011, 07:31:04 pm Hello. I did something in EJS, but it doesn't work correctly. I attach my source code. This is a highly nonlinear model. How i can insert limit variable x1, x3, x4 ? Title: Re: Magnetic levitation model 2 Post by: Fu-Kwun Hwang on June 25, 2011, 03:58:06 pm Quote from: cruels on June 15, 2011, 09:00:51 pmThank you for your replyx1 position of the ball - 0 when the ball touches EM1, 0.016 when the ball touches EM2 - unit [meter]x2 velocity - unit [meter per second]x3 current in EM1 - unit [Ampere]x4 current in EM2 - unit [Ampere]Only magnet ball is movablePlease provide the possible range of x1 (from 0 to ???)From the above picture $x1\in [0,0.016]$  , do you mean $0\le x1\le 0.016$.However, the initial value for x1 is 0.09 in your source code. I am really confused.Please also provide the size of the ball and Initial values for x2,x3,x4I need those information in order to help (Those values assigned in the maglevkam.ejs  are different from what you have provided in the previous posts). Title: Re: Magnetic levitation model 2 Post by: cruels on June 25, 2011, 05:07:52 pm Range of x1 is form 0 to 0.016. ($0\le x1\le 0.016$). This is the maximum distance between the electromagnet EM1 and ball. I have mistake in my source code. Ball diameter is 0.06 meterThe initial value:x1 = 0.009x2 = 0x3 = 0.9345x4 = 0It means that the ball velocity is equal zero. The ball is levitating kept at the 9 mm distance from the bottom of the upper electromagnet. The 0.9345 A current flowing through the magnetic coil is the appropriate value to balance the gravity force of the ball. Title: Re: Magnetic levitation model 2 Post by: Fu-Kwun Hwang on June 27, 2011, 09:11:13 am The diameter of the ball is 0.06meter, it means that the radius is 3cm.Then the volume will be $\frac{4}{3}\pi r^4\approx 108 cm^3$You have provided that  mass $m=0.0571 kg=57.1g$Then, the density of the ball is about $57/108\approx 0.5 g/cm^3$. This seems to be quite small (less than water. ???).I did check out your code and try to run it(step by step). The value grow very rapidly. It might be due to some mistake (or wrong number or wrong sign) in the code.Could you check out all those parameters again? Title: Re: Magnetic levitation model 2 Post by: cruels on June 27, 2011, 12:27:05 pm These parameters and equations are in the instructions which I attach. I'll check the weight ball. Title: Re: Magnetic levitation model 2 Post by: Fu-Kwun Hwang on July 02, 2011, 09:12:46 am Here is the simulation according to your model.However, I did not find the range where it is stable.You can use controlled feedback to make it stable.  Title: Re: Magnetic levitation model 2 Post by: jmartin12 on July 25, 2011, 12:37:20 am Control feedback can work in this model. Have you applied control feed back?But the feedback used must be accurate to get desired Maglev range stability.james-*- Title: Re: Magnetic levitation model 2 Post by: seikialice88 on December 22, 2011, 02:06:42 pm Quote from: cruels on June 12, 2011, 04:57:14 pmHelloI need to create a model of Magnetic levitation. I read the post at http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1683.0 but modification of this simulation is too hard for me. Could anyone help me? I attach my equationsSuch a very amazing link!-*- Title: Re: Magnetic levitation model 2 Post by: homertyson on March 08, 2013, 05:45:06 pm Magnetic Levitation occurs when an item, such as a train seemingly floats above the ground by way of a clever use of magnets. You can make a Magnetic Levitation experiment at home very easily using some simply materials.-*-