MATLAB: Velocity,A​cceleratio​n,Angle

accelerationanglehomeworkplotsvelocity

How do I find plots for
velocity of link3 vs angle of link1 Acceleration of link3 vs angle of link1.

Best Answer

This is a dynamics class. Dynamics involves derivatives. How can you be in a dynamics class without knowing calculus and how to take derivatives? All you have to do is know how to take the derivative of sqrt and trig functions and apply some chain rule stuff to get your answer. E.g., if you had the following for the x-coordinate of point B with respect to point A:
Bx = L1 * cos(phi1)
And you were asked to find the velocity of the x-coordinate of point B, then the derivative of Bx with respect to time would be
d(Bx)/dt = -L1 * sin(phi1) * d(phi1)/dt
And since they told you that phi1 is changing with constant angular rate w1, you get
d(Bx)/dt = -L1 * sin(phi1) * w1 <-- Velocity of Bx
If you were asked about the acceleration of Bx, then take another derivative:
d2(Bx)/dt^2 = -L1 * cos(phi1) * d(phi1)/dt * w1
And again knowing that d(phi1)/dt is the constant w1 you get
d2(Bx)/dt^2 = -L1 * cos(phi1) * w1^2 <-- Acceleration of Bx
This is simple calculus. You have to know this stuff to get by in a dynamics class. Just apply this method to the L3 equation I gave you above.
Related Question