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Author Topic: Magnetic levitation model 2  (Read 11122 times)
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cruels
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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 336 times.)
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Fu-Kwun Hwang
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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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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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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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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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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 Huh)
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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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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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. Huh).

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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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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« Last Edit: June 27, 2011, 12:28:57 pm by cruels » Logged
Fu-Kwun Hwang
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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

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jmartin12
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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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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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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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