Recent content by mharaghi

this code is the way it should be implemented, (a freq component was missed in your code). This is still not correct, and I am missing something, some coefficient ... clc sr=10000; dt=1/sr; len=0.05; t=0:dt:len; f=500; %generate signal sig=sin(2*pi*f*t); %Define a phase shift in...

the problem arises because the signal loses it symmetry, and the ifft gives a complex answer. it is obvious that a shifted sine doesn't have a complex component... You can test it, by manually adding a delay to the inpt sine wave and see it's symmetric fourier. but by adding the...

to me, when it is in resonant frequency means it is a positive feedback, and essentially goes unbound. Since it doesn't go unbound (becomes constant), it is limited to some saturation limits. Therefore, the magnitude is dependent on some saturation limits. This saturation can be caused by a very...

there are damping and hysteresis, dashpots, piezoelectric material resposne.

specifically, we have an input u1 (which is defined by me, idk what it should be to best fit the problem) there is a plant, which essentially has a res. freq. and outputs a displacement... the displacement is captured via a sensor, as signal, say f1 it is fed back, to u1... I guess...

n the top of my head, phase angle should be -180 (margin zero), so it is essentially a positive feedback (output in phase with input with a -360 lag). gain margin should be zero (logarithmic), right??

I searched and found nothing of particular interest... I didn't put the complete situation, anyway. there is the actuator, then some spring and proof mass, and tip mass, which causes it to have a res. freq. This is captured by a sensor, and fed back. Essentially a biological tissue is also in...

the A is incorrect because it says when the oscillations are constant, which means we arein the steady-state response. Damping shows its effects in the transient time, not in the steady-state time, so the amplitude has become larger and larger, and it became constant eventually, and afterwards...

I can give the following description to the problem, but I don't specifically know what should be done to drive an actuator (specially a piezoeelctric one) in its resonance frequency using a feedback. **The sensor consists of a piezoelectric transducer and a vibration pickup. When an...