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"Nothing in life is to be feared, it is only to be understood." ..."Marie Curie 1867-1934, Polish born French Physicist, Twice Nobel Prize Winner- Physics and Chemistry)"

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 Author Topic: Magnetic levitation model 2  (Read 13884 times) 0 Members and 1 Guest are viewing this topic. Click to toggle author information(expand message area).
cruels
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 « Embed this message on: June 12, 2011, 04:57:14 pm » posted from:Wola,Kujawsko-Pomorskie,Poland

Hello
I 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
 equation.jpg (82.08 KB, 1051x767 - viewed 517 times.) Logged
Fu-Kwun Hwang
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 « Embed this message Reply #1 on: June 15, 2011, 02:01:53 pm » posted from:Taipei,T'ai-pei,Taiwan

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.
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cruels
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 « Embed this message Reply #2 on: June 15, 2011, 09:00:51 pm » posted from:Wroclaw,Dolnoslaskie,Poland

Thank you for your reply
x1 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
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Fu-Kwun Hwang
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 « Embed this message Reply #3 on: June 15, 2011, 10:42:27 pm » posted from:Taipei,T'ai-pei,Taiwan

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.
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cruels
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 « Embed this message Reply #4 on: June 24, 2011, 07:31:04 pm » posted from:Mikolow,Slaskie,Poland

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 ?
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Fu-Kwun Hwang
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 « Embed this message Reply #5 on: June 25, 2011, 03:58:06 pm » posted from:Taipei,T'ai-pei,Taiwan

Thank you for your reply
x1 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

Please 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,x4

I 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).
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cruels
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 « Embed this message Reply #6 on: June 25, 2011, 05:07:52 pm » posted from:-,-,POLAND

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 meter
The initial value:
x1 = 0.009
x2 = 0
x3 = 0.9345
x4 = 0
It 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.
 « Last Edit: June 25, 2011, 06:42:45 pm by cruels » Logged
Fu-Kwun Hwang
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 « Embed this message Reply #7 on: June 27, 2011, 09:11:13 am » posted from:Taipei,T'ai-pei,Taiwan

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?
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cruels
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 « Embed this message Reply #8 on: June 27, 2011, 12:27:05 pm » posted from:Katowice,Slaskie,Poland

These parameters and equations are in the instructions which I attach. I'll check the weight ball.
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Fu-Kwun Hwang
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 « Embed this message Reply #9 on: July 02, 2011, 09:12:46 am » posted from:Taipei,T'ai-pei,Taiwan

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.

Embed a running copy of this simulation

Embed a running copy link(show simulation in a popuped window)
Full screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License
• Please feel free to post your ideas about how to use the simulation for better teaching and learning.
• Post questions to be asked to help students to think, to explore.
• Upload worksheets as attached files to share with more users.
Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!
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jmartin12
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 « Embed this message Reply #10 on: July 25, 2011, 12:37:20 am » posted from:Dhaka,Dhaka,Bangladesh

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-*-
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seikialice88
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 « Embed this message Reply #11 on: December 22, 2011, 02:06:42 pm » posted from:HANOI,HA NOI,VIET NAM

Hello
I 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
Such a very amazing link!
-*-
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homertyson
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 « Embed this message Reply #12 on: March 08, 2013, 05:45:06 pm » posted from:Guntur,Andhra Pradesh,India

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.-*-

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"Nothing in life is to be feared, it is only to be understood." ..."Marie Curie 1867-1934, Polish born French Physicist, Twice Nobel Prize Winner- Physics and Chemistry)"
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