def calculate_velocity(read_data):
photogate_derivative = np.diff(read_data)
one_section_period = fan.peak_separation(photogate_derivative,
dt,
prominence=1,
height=2)
return circunference / (chopper_sections * one_section_period)
def calculate_photogate_frequency(read_data):
"""Returns frequency of photogate signal expressed on a.u."""
# This function is used to analyze each measurement
photogate_derivative = np.diff(read_data)
photogate_period = fan.peak_separation(photogate_derivative,
prominence=1,
height=2)
return 1 / photogate_period
def calculate_velocity_error(data):
time = data[:,0]
read_data = data[:,1]
photogate_derivative = np.diff(read_data)
one_section_period, error = peak_separation(
photogate_derivative,
np.mean(np.diff(time)),
prominence=1,
height=2,
return_error=True)
velocity = circunference / (chopper_sections * one_section_period)
error = circunference*error/(chopper_sections*one_section_period**2)
return velocity, error
def calculate_duty(read_data):
global last_velocity
# Now I apply PID
photogate_derivative = np.diff(read_data)
try:
angular_velocity = fan.peak_separation(photogate_derivative,
pid.dt,
prominence=1,
height=2)
velocity = angular_velocity * wheel_radius
except ValueError: # No peaks found
velocity = pid.last_log.feedback_value # Return last value
new_dc = pid.calculate(velocity)
return new_dc