Ramakrishnan

Dr. Ramakrishnan Vaidyanathan

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4 years, 358 days

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I have retired as Professor-Mechanical in Sri Venkateswara College of Engineering and Technology under Anna University affiliated colleges in Tamil Nadu, India. I have 19 years of Industrial and 20 years of teaching experience. I am learning Maple for the past four and half years hoping to make at least one appreciable maple presentation.

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These are questions asked by Ramakrishnan

I dragged into model space prismatic FixedFrame and RigidBody components and prismatic joint along y axis. I also set mass m = 1 kg. The manual says set K_S = K_S and K_K_d in inspector parameter setting. It did not work out. So i set values 12 and 0.1 for K_S and K_d. I sreated subsystem sub of rigidBody and followed the following instructions,

Quote" PrismaticJoint.PlacethePrismaticjointandRigidBodyinasubsystemcalledsub.Thisallowsthe EquationTemplatetogenerateequationsspecificallyfortheselectedsubsystem.
3. ClickTemplates( )intheMainToolbarandselecttheEquationstemplate. 4. IntheAttachmentfield,provideaworksheetnameandclickCreateAttachment.Your MapleSimmodelopensinaMapleworksheet,withtheSubsystemSelectionwindow.

ClickLoadSelectedSubsystem.Thesubcomponentparameterandvariablesload automaticallyintheParameterandVariableManipulationareas"

After this i wanted to modify the equations. I could not. The same equation is reassigned.

Parameter and variable rows - are as shown in manual, but a blank row not available for user's use. But how do i get the variable x(t) there and rename it?

Thanks for an example of this chapter with an application of its use., if available with anyone?

Ramakrishnan V

I have made a program to plot y(t) vs x(t). Can you please modify to plot y vs x data from an excel file.

Given x in A column and y in B column in 5 rows.

Example data: [[1,1],[2,4],[3,9],[4,16],[5,26]]

StLine_VRK.msim

Thanks.

Ramakrishnan V

I followed the basic example RLS circuit first. It worked out well for R = 24 ohms, L = 160 mHand C = 200 microF. Signal is step input h = 1 and  t0 =  0.1 s. Simulation td = 0.5 s

When I extended it for DC motor, the output for torque (tou) and speed (w) not plotted for h = 1  t0 =  1s and simulation td = 5 s for the same parameters as above the output required (shown in manual) is not coming. Is it because default values shown were different? Then how do i change? I am enclosing the file for view and help.

DCmotort_model1.msim

 

Thanks.

Ramakrishnan V

[[1000, 20], [2000, 25], [3000, 24], [4000, 23], [5000, 24]];
  [[1000, 20], [2000, 25], [3000, 24], [4000, 23], [5000, 24]]
data1 := [[1000, 20], [2000, 21], [3000, 32], [4000, 23], [5000, 23]]; 'data1';
                             data1
a*x^3+b*x^2+c*x+d;
                        3      2          
                     a x  + b x  + c x + d
x;
                               x
Equn1 := CurveFitting[LeastSquares]([[1000, 20], [2000, 25], [3000, 24], [4000, 23], [5000, 24]], x, curve = a*x^3+b*x^2+c*x+d);
plot(Equn1,x= 1000..5000)


 

Least Squares Approximation

 

 

Calculate a least squares approximation using specified data points.

 

 

Theoretical Curves for the Two-Stroke Engines and Four-Stroke Engines Brake Power Vs Brake Efficiency

List of Data Points:

[[1000, 20], [2000, 25], [3000, 24], [4000, 23], [5000, 24]]

[[1000, 20], [2000, 25], [3000, 24], [4000, 23], [5000, 24]]

(1)

data1 := [[1000, 20], [2000, 21], [3000, 32], [4000, 23], [5000, 23]]; 'data1'

data1

(2)

Fitting Curve:

a*x^3+b*x^2+c*x+d

a*x^3+b*x^2+c*x+d

(3)

Independent Variable:

x

x

(4)

Least Squares Curve:

Equn1 := CurveFitting[LeastSquares]([[1000, 20], [2000, 25], [3000, 24], [4000, 23], [5000, 24]], x, curve = a*x^3+b*x^2+c*x+d)

plot(Equn1,x= 1000..5000)

 

 

 

 

NULL

Equn1

31/5+(83/4200)*x-(23/3500000)*x^2+(1/1500000000)*x^3

(5)

 

 

Least Squares Fit of Data by a Specified Curve

List of Data Points:

[[3, -1], [5, 3], [6, -7], [7, 5], [9, -2]]

[[3, -1], [5, 3], [6, -7], [7, 5], [9, -2]]

(6)

Fitting Curve:

a*x^2+b*x+c

a*x^2+b*x+c

(7)

Independent Variable:

x

x

(8)

Least Squares Curve:

CurveFitting[LeastSquares]([[3, -1], [5, 3], [6, -7], [7, 5], [9, -2]], x, curve = a*x^2+b*x+c)

-901/210+(213/140)*x-(11/84)*x^2

(9)
 

 

a*x^2+b*x+c

a*x^2+b*x+c

(10)

plot(sin(x), x = 0 .. 4*Pi)

 

``


 

Download LeastSquareApproximation_2nd_and_3rd_Order.mw

The above command plots one curve alright. I want four such curves to go in the same figure using command like

plot(Equn1,Equn2,Equn3,Equn4,view(x=1000..5000)

I am not getting by the above command what I want. Can any one help. A shortcut method is required for me to repeat many times.

Thanks for help.

Ramakrishnav V
 

 

a := Matrix(2, 2, {(1, 1) = 1, (1, 2) = 2, (2, 1) = 3, (2, 2) = 4})with(LinearAlgebra)

 

a.a^T = (Matrix(2, 2, {(1, 1) = 1, (1, 2) = 2, (2, 1) = 3, (2, 2) = 4})).(Matrix(2, 2, {(1, 1) = 1, (1, 2) = 2, (2, 1) = 3, (2, 2) = 4}))^TNULL

I am not getting the answer.

I want to get the answer for this product of matrix and its tranport.

I do not want to create transport matrix again for this calculation.

The transporse matrix b is

b := Matrix(2, 2, {(1, 1) = 1, (1, 2) = 3, (2, 1) = 2, (2, 2) = 4}) = Matrix([[1, 3], [2, 4]])

a.a^T is equal to a.b = Matrix([[5, 11], [11, 25]])NULL

For large matrices i cannot do this. Hence this request.Any one please send the code. Thanks.

 

Download transpose_doubt_1.mwtranspose_doubt_1.mw

Ramakrishnan V

rukmini_ramki@hotmail.com

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