Derivation for modified sine curve equations

  • #1
balaji19991
4
0
Hello,
I am looking for a detailed derivation of the equations used to generate the modified sine curve. I found one in Cam design handbook by Harold A. Rothbart but I didn't understand how we get certain equations. My end goal is to combine the modified sine curve with constant velocity and get equations for those to generate the necessary displacement,velocity and acceleration graphs.
 
Engineering news on Phys.org
  • #2
Welcome to PF.

The modified sine curves are usually generated by adding small amounts of odd harmonics to the fundamental.
You will need to specify how modified you want the curves to be.
Given sufficient harmonics, you could synthesise a square or a triangle wave. But sharp corners and vertical edges are impossible in the engineering world because they require infinite forces, and infinite energy, to create infinite acceleration .

Which one in the Cam Design Handbook did you like?
 
  • Like
Likes balaji19991
  • #3
Baluncore said:
Welcome to PF.

The modified sine curves are usually generated by adding small amounts of odd harmonics to the fundamental.
You will need to specify how modified you want the curves to be.
Given sufficient harmonics, you could synthesise a square or a triangle wave. But sharp corners and vertical edges are impossible in the engineering world because they require infinite forces, and infinite energy, to create infinite acceleration .

Which one in the Cam Design Handbook did you like?
I wanted the standard modified sine curve where two sine waves of frequencies Beta/2 and 3Beta/2 are combined. The modified sine curve inside the handbook is what I am looking for. I used those final equations and got the result i wanted. But I want to understand the derivation.
Once I understand the derivation probably I could derive equations to generate a constant velocity curve with sinusoidal acceleration.
 
  • #4
balaji19991 said:
I wanted the standard modified sine curve where two sine waves of frequencies Beta/2 and 3Beta/2 are combined.
There are 600 pages of detail in the Cam Design Handbook, please give me a section, or the equation number in the text.
 
  • #5
Baluncore said:
There are 600 pages of detail in the Cam Design Handbook, please give me a section, or the equation number in the text.
Oh sorry I didn't know you have the handbook.
Chapter 3 modified cam curves.
The derivation starts on page 73 (3.7 modified sine curve) and equation 3.15 on page 74 is what I am unable to figure out.
 
  • #6
balaji19991 said:
Oh sorry I didn't know you have the handbook.
It just so happens, that I found a copy, that had just fallen off the back of a fibre-optic truck.

The quadrants have different generation equations, that blend at the transitions. You may need to go back to look at the referenced paper to find the origin of equation 3.15 .
 
  • Like
Likes balaji19991
  • #7
Baluncore said:
It just so happens, that I found a copy, that had just fallen off the back of a fibre-optic truck.

The quadrants have different generation equations, that blend at the transitions. You may need to go back to look at the referenced paper to find the origin of equation 3.15 .
That was exactly my first thought but to my surprise i couldn't find any research papers related to this topic on the internet .If you know where it can be found please help me out.
 

Related to Derivation for modified sine curve equations

1. How do you derive the equation for a modified sine curve?

To derive the equation for a modified sine curve, you start with the general equation for a sine curve, y = A sin(Bx + C), and then modify the values of A, B, and C based on the specific characteristics of the curve you are working with.

2. What are the key differences between a regular sine curve and a modified sine curve?

The key differences between a regular sine curve and a modified sine curve are the values of A, B, and C in the equation. A modified sine curve may have a different amplitude (A), period (2π/B), and phase shift (C) compared to a regular sine curve.

3. How do you determine the amplitude of a modified sine curve?

The amplitude of a modified sine curve is determined by the coefficient A in the equation y = A sin(Bx + C). The amplitude is the distance from the midline of the curve to its maximum or minimum value, and it is equal to half the difference between the maximum and minimum values of the curve.

4. Can you explain the concept of phase shift in a modified sine curve?

Phase shift in a modified sine curve refers to the horizontal shift of the curve along the x-axis. It is determined by the value of C in the equation y = A sin(Bx + C). A positive phase shift moves the curve to the right, while a negative phase shift moves it to the left.

5. How can the equation for a modified sine curve be used in real-world applications?

The equation for a modified sine curve can be used to model various periodic phenomena in real-world applications, such as electrical waveforms, sound waves, and mechanical vibrations. By adjusting the parameters of the equation, scientists and engineers can accurately describe and analyze these phenomena.

Similar threads

Replies
34
Views
1K
  • General Engineering
Replies
4
Views
10K
  • General Engineering
Replies
6
Views
2K
Replies
49
Views
1K
  • Classical Physics
Replies
25
Views
1K
  • MATLAB, Maple, Mathematica, LaTeX
Replies
9
Views
1K
Replies
72
Views
5K
  • High Energy, Nuclear, Particle Physics
Replies
8
Views
929
Replies
2
Views
1K
  • Calculus and Beyond Homework Help
Replies
14
Views
625
Back
Top