+- Python Forum (https://python-forum.io)
+-- Forum: Python Coding (https://python-forum.io/forum-7.html)
+--- Forum: Data Science (https://python-forum.io/forum-44.html)
+--- Thread: Acceleration to velocity (/thread-37189.html)
Acceleration to velocity - frohr - May-10-2022
Hi,
I want to ask you if I have correct calculation of velocity fom acceleration. It is for vibration analysis.
I have ADXL1005 and I acquire data to buffer with sampling frequency 30000. Acceleration must be from 10 to 1000Hz.
Now I have array in Python and calculation. But I am not sure if this method correct.
def mm_RMS(self):
accelerationl[0:30000] = read_adxl[0:30000]
velocity = 0
speed_mm = 0
time_mm = 0
velocity_tot = []
lowcut = 10.0
highcut = 1000.0
get_mms = butter_bandpass_filter(acceleration, lowcut, highcut, 30000, order=4)
for i in range(0, 30000):
velocity = speed_mm + (acceleration[i] * time_mm)
speed_mm = velocity
time_mm = time_mm + 1/30000
velocity_tot.append(velocity ** 2)
tot_mm = sum(velocity_tot)
tot_mm = tot_mm / 30000
tot_mm = math.sqrt(tot_mm)
print("mm/s: " + str(round(tot_mm,2))) I am not sure, maybe is much better method. Thanks for any advice.
RE: Acceleration to velocity - deanhystad - May-10-2022
If you just want to know the velocity at the end of your sample:
velocity += sum(acceleration) / 30000Just like you were doing for displacement.
If you want a velocity for each acceleration point, I would use numpy.trapz()
https://numpy.org/doc/stable/reference/generated/numpy.trapz.html
You could do this again to get a time history of displacement.