30+ years experience in missiles, smart munitions and other aerodynamic systems. Specializing in systems engineering, aerospace systems design, simulation and modeling, aerodynamics, and numerical analysis.

Currently developing simulations for the Advanced Technology group of the Missile Defense Agency

Answered

How to find the angle between two quaternions?

I am more comfortable working with direction cosine matrices, so the way I would do this is to first convert the quaternions to ...

How to find the angle between two quaternions?

I am more comfortable working with direction cosine matrices, so the way I would do this is to first convert the quaternions to ...

9 jours ago | 1

Answered

Eliminate algebraic loop without using memory block

Here is an interesting article on algebraic loops and memory blocks. (pertaining to continuous time models) https://blogs.math...

Eliminate algebraic loop without using memory block

Here is an interesting article on algebraic loops and memory blocks. (pertaining to continuous time models) https://blogs.math...

11 jours ago | 0

Answered

how to I add add a text in the Notes section (below the ppt slide)

on the VIEW tab, click on "notes page"

how to I add add a text in the Notes section (below the ppt slide)

on the VIEW tab, click on "notes page"

11 jours ago | 0

Answered

calculate difference of euler angles between two dynamic moving objects

You have two objects described in a common reference frame. Lets call the objects A and B, and the frame is the I frame. So if...

calculate difference of euler angles between two dynamic moving objects

You have two objects described in a common reference frame. Lets call the objects A and B, and the frame is the I frame. So if...

13 jours ago | 1

| accepted

Answered

Is it possible to only rename instances of a variable that appear in the code after the point at which you edit the variable selected? (shift+enter)

I use a tool called UltraEdit. It has that capability. In the find/replace tab there is a checkbox for "replace all is from t...

Is it possible to only rename instances of a variable that appear in the code after the point at which you edit the variable selected? (shift+enter)

I use a tool called UltraEdit. It has that capability. In the find/replace tab there is a checkbox for "replace all is from t...

13 jours ago | 0

Answered

program to find velocity of a UAV

This is a fun problem (aircraft design). I guess it's OK to give an answer on this, since it was homework 8 years ago! A quick...

program to find velocity of a UAV

This is a fun problem (aircraft design). I guess it's OK to give an answer on this, since it was homework 8 years ago! A quick...

19 jours ago | 0

Answered

how can i calculate the energy of the pixel in the image??

Here are a couple possible references https://www.mathworks.com/matlabcentral/answers/63441-to-find-energy-of-each-pixel-from-a...

how can i calculate the energy of the pixel in the image??

Here are a couple possible references https://www.mathworks.com/matlabcentral/answers/63441-to-find-energy-of-each-pixel-from-a...

19 jours ago | 0

Answered

simulink output size is not same as input size

The answer has to do with how you are saving variable "temp" from Simulink, but I cannot tell from the screenshot how this is be...

simulink output size is not same as input size

The answer has to do with how you are saving variable "temp" from Simulink, but I cannot tell from the screenshot how this is be...

20 jours ago | 0

Answered

Eulers method range issue question

In your code, you specify: R=[1:16]; h=0.2; ic=4; Then you call the function [t,y]=myEuler(f,R,ic,h) Inside myEuler, it co...

Eulers method range issue question

In your code, you specify: R=[1:16]; h=0.2; ic=4; Then you call the function [t,y]=myEuler(f,R,ic,h) Inside myEuler, it co...

24 jours ago | 1

Answered

How do you use Euler's Method to approximate the solution?

Euler's method approximates the area under a curve by using rectangular segments. The figure illustrates this process: You s...

How do you use Euler's Method to approximate the solution?

Euler's method approximates the area under a curve by using rectangular segments. The figure illustrates this process: You s...

25 jours ago | 0

| accepted

Answered

Coorindate transforms to a satellite reference frame

In order to answer this question, we need a good definition of the coordinate frames involved. The only way to do this is to dr...

Coorindate transforms to a satellite reference frame

In order to answer this question, we need a good definition of the coordinate frames involved. The only way to do this is to dr...

27 jours ago | 0

Answered

How do I execute a function only one time in Simulink?

This is what rate transition blocks were created for. You might want to try this approach. Simply insert a rate transition blo...

How do I execute a function only one time in Simulink?

This is what rate transition blocks were created for. You might want to try this approach. Simply insert a rate transition blo...

27 jours ago | 0

Answered

How to substract one number from many numbers?

W = x - 0.6 Or, if you want to actualy subtract x from 0.6 it would be: W = -x + 0.6

How to substract one number from many numbers?

W = x - 0.6 Or, if you want to actualy subtract x from 0.6 it would be: W = -x + 0.6

27 jours ago | 0

| accepted

Answered

How do I export a vector to workspace in simulink?

It'a actually very easy. Simulink has a block for combining two signals, called a "mux" block. Simply combine the two signals ...

How do I export a vector to workspace in simulink?

It'a actually very easy. Simulink has a block for combining two signals, called a "mux" block. Simply combine the two signals ...

environ 2 mois ago | 0

Answered

thermodynamic properties of water in simulink

Sounds like a perfect application for using a table look-up. For a function of two variables, simulink has a "2-D Lookup Table...

thermodynamic properties of water in simulink

Sounds like a perfect application for using a table look-up. For a function of two variables, simulink has a "2-D Lookup Table...

2 mois ago | 0

Answered

Index exceeds the number of array elements (1)

In the calculation of xdot I see subscripted references for x (up to 12) and u (up to 4). You should check the size of x and u ...

Index exceeds the number of array elements (1)

In the calculation of xdot I see subscripted references for x (up to 12) and u (up to 4). You should check the size of x and u ...

2 mois ago | 0

| accepted

Answered

how simulate PI ?

Yes, it's that easy. Did you try it? What are the results?

how simulate PI ?

Yes, it's that easy. Did you try it? What are the results?

2 mois ago | 1

Question

Is Walter Roberson a real person, or is he some kind of Matlab AI robot?

Just curious!

3 mois ago | 8 answers | 13

Answered

solve 4th order ode in simulink

Your diagram looks reasonable to me and it could work, but its hard to tell from a screen shot - especially when the block title...

solve 4th order ode in simulink

Your diagram looks reasonable to me and it could work, but its hard to tell from a screen shot - especially when the block title...

3 mois ago | 1

Answered

Finding the roots of equation by newton-raphson method?

I would approach the problem like this (this is a very simple implementation) Define an annonymous function for your equation: ...

Finding the roots of equation by newton-raphson method?

I would approach the problem like this (this is a very simple implementation) Define an annonymous function for your equation: ...

4 mois ago | 2

| accepted

Answered

circle least square method

You don't need to use least squares to "fit" a circle to 3 points, because 3 points will uniquely define a single circle. See ...

circle least square method

You don't need to use least squares to "fit" a circle to 3 points, because 3 points will uniquely define a single circle. See ...

4 mois ago | 0

Answered

creating sine wave with variable frequency

The reason that the frequency is constant is that you are driving it with a linear function of time. If you plot the input sign...

creating sine wave with variable frequency

The reason that the frequency is constant is that you are driving it with a linear function of time. If you plot the input sign...

4 mois ago | 1

| accepted

Answered

Simulink (switch)

This problem may be complicated since you have 2 different definitions of x. However, based on what you asked for, this should w...

Simulink (switch)

This problem may be complicated since you have 2 different definitions of x. However, based on what you asked for, this should w...

5 mois ago | 0

Answered

Problem executing While loop

You need to move the statement k=k+1 outside of the if block. The first time you run the while loop, k has a value of 10, an...

Problem executing While loop

You need to move the statement k=k+1 outside of the if block. The first time you run the while loop, k has a value of 10, an...

5 mois ago | 1

Answered

mistake how can i stop

You probably want a loop from X=100:200 Inside your loop, you select the cases you want: e.g. for x=100:200 condition1 = ...

mistake how can i stop

You probably want a loop from X=100:200 Inside your loop, you select the cases you want: e.g. for x=100:200 condition1 = ...

5 mois ago | 0

Answered

Hello everyone. I'm trying to plot first , second and third order functions on the same graph. heres what i have so far. Its only giving me the last function. Any help would be much appreciated

Try this: figure; plot(x,y,'r'); hold on; plot(x,y2,'b'); In the plot command(s) replace the 'r' and the 'b with whatever p...

Hello everyone. I'm trying to plot first , second and third order functions on the same graph. heres what i have so far. Its only giving me the last function. Any help would be much appreciated

Try this: figure; plot(x,y,'r'); hold on; plot(x,y2,'b'); In the plot command(s) replace the 'r' and the 'b with whatever p...

5 mois ago | 0

Answered

Draw a circle from 3 point

If you have the coordinates of the three points, you can use the method in the attached document.

Draw a circle from 3 point

If you have the coordinates of the three points, you can use the method in the attached document.

6 mois ago | 0

| accepted

Answered

How can I use simulink without time simulation?

If your timestep is constant, you can set your model to run at a fixed timestep. You can even specify a non-zero start time if ...

How can I use simulink without time simulation?

If your timestep is constant, you can set your model to run at a fixed timestep. You can even specify a non-zero start time if ...

6 mois ago | 1

| accepted

Answered

Averaging a signal at periodic intervals in Simulink

In my mind, the easiest way to do this is to create a Matlab function to do it, and embed the function into a Matlab block in Si...

Averaging a signal at periodic intervals in Simulink

In my mind, the easiest way to do this is to create a Matlab function to do it, and embed the function into a Matlab block in Si...

6 mois ago | 1

Answered

Spring motion using Euler method

Since k has a value of -20, the value of w is a complex number, with a purely imaginary value.

Spring motion using Euler method

Since k has a value of -20, the value of w is a complex number, with a purely imaginary value.

6 mois ago | 0