146 lines
4.7 KiB
Python
Executable File
146 lines
4.7 KiB
Python
Executable File
#!/usr/bin/env python2
|
|
# Generate extruder pressure advance motion graphs
|
|
#
|
|
# Copyright (C) 2019 Kevin O'Connor <kevin@koconnor.net>
|
|
#
|
|
# This file may be distributed under the terms of the GNU GPLv3 license.
|
|
import math, optparse, datetime
|
|
import matplotlib
|
|
|
|
SEG_TIME = .000100
|
|
INV_SEG_TIME = 1. / SEG_TIME
|
|
|
|
|
|
######################################################################
|
|
# Basic trapezoid motion
|
|
######################################################################
|
|
|
|
# List of moves: [(start_v, end_v, move_t), ...]
|
|
Moves = [
|
|
(0., 0., .200),
|
|
(0., 100., None), (100., 100., .200), (100., 60., None),
|
|
(60., 100., None), (100., 100., .200), (100., 0., None),
|
|
(0., 0., .300)
|
|
]
|
|
EXTRUDE_R = (.4 * .4 * .75) / (math.pi * (1.75 / 2.)**2)
|
|
ACCEL = 3000. * EXTRUDE_R
|
|
|
|
def gen_positions():
|
|
out = []
|
|
start_d = start_t = t = 0.
|
|
for start_v, end_v, move_t in Moves:
|
|
start_v *= EXTRUDE_R
|
|
end_v *= EXTRUDE_R
|
|
if move_t is None:
|
|
move_t = abs(end_v - start_v) / ACCEL
|
|
half_accel = 0.
|
|
if end_v > start_v:
|
|
half_accel = .5 * ACCEL
|
|
elif start_v > end_v:
|
|
half_accel = -.5 * ACCEL
|
|
end_t = start_t + move_t
|
|
while t <= end_t:
|
|
rel_t = t - start_t
|
|
out.append(start_d + (start_v + half_accel * rel_t) * rel_t)
|
|
t += SEG_TIME
|
|
start_d += (start_v + half_accel * move_t) * move_t
|
|
start_t = end_t
|
|
return out
|
|
|
|
def gen_deriv(data):
|
|
return [0.] + [(data[i+1] - data[i]) * INV_SEG_TIME
|
|
for i in range(len(data)-1)]
|
|
|
|
def time_to_index(t):
|
|
return int(t * INV_SEG_TIME + .5)
|
|
|
|
|
|
######################################################################
|
|
# Pressure advance
|
|
######################################################################
|
|
|
|
PA_HALF_SMOOTH_T = .040 / 2.
|
|
PRESSURE_ADVANCE = .045
|
|
|
|
def calc_pa_raw(t, positions):
|
|
pa = PRESSURE_ADVANCE * INV_SEG_TIME
|
|
i = time_to_index(t)
|
|
return positions[i] + pa * (positions[i+1] - positions[i])
|
|
|
|
def calc_pa_smooth(t, positions):
|
|
start_index = time_to_index(t - PA_HALF_SMOOTH_T) + 1
|
|
end_index = time_to_index(t + PA_HALF_SMOOTH_T)
|
|
pa = PRESSURE_ADVANCE * INV_SEG_TIME
|
|
pa_data = [positions[i] + pa * (positions[i+1] - positions[i])
|
|
for i in range(start_index, end_index)]
|
|
return sum(pa_data) / (end_index - start_index)
|
|
|
|
|
|
######################################################################
|
|
# Plotting and startup
|
|
######################################################################
|
|
|
|
MARGIN_TIME = 0.100
|
|
|
|
def plot_motion():
|
|
# Nominal motion
|
|
positions = gen_positions()
|
|
drop = int(MARGIN_TIME * INV_SEG_TIME)
|
|
times = [SEG_TIME * t for t in range(len(positions))][drop:-drop]
|
|
velocities = gen_deriv(positions[drop:-drop])
|
|
# Motion with pressure advance
|
|
pa_positions = [calc_pa_raw(t, positions) for t in times]
|
|
pa_velocities = gen_deriv(pa_positions)
|
|
# Smoothed motion
|
|
sm_positions = [calc_pa_smooth(t, positions) for t in times]
|
|
sm_velocities = gen_deriv(sm_positions)
|
|
# Build plot
|
|
shift_times = [t - MARGIN_TIME for t in times]
|
|
fig, ax1 = matplotlib.pyplot.subplots(nrows=1, sharex=True)
|
|
ax1.set_title("Extruder Velocity")
|
|
ax1.set_ylabel('Velocity (mm/s)')
|
|
pa_plot, = ax1.plot(shift_times, pa_velocities, 'r',
|
|
label='Pressure Advance', alpha=0.3)
|
|
nom_plot, = ax1.plot(shift_times, velocities, 'black', label='Nominal')
|
|
sm_plot, = ax1.plot(shift_times, sm_velocities, 'g', label='Smooth PA',
|
|
alpha=0.9)
|
|
fontP = matplotlib.font_manager.FontProperties()
|
|
fontP.set_size('x-small')
|
|
ax1.legend(handles=[nom_plot, pa_plot, sm_plot], loc='best', prop=fontP)
|
|
ax1.set_xlabel('Time (s)')
|
|
ax1.grid(True)
|
|
fig.tight_layout()
|
|
return fig
|
|
|
|
def setup_matplotlib(output_to_file):
|
|
global matplotlib
|
|
if output_to_file:
|
|
matplotlib.rcParams.update({'figure.autolayout': True})
|
|
matplotlib.use('Agg')
|
|
import matplotlib.pyplot, matplotlib.dates, matplotlib.font_manager
|
|
import matplotlib.ticker
|
|
|
|
def main():
|
|
# Parse command-line arguments
|
|
usage = "%prog [options]"
|
|
opts = optparse.OptionParser(usage)
|
|
opts.add_option("-o", "--output", type="string", dest="output",
|
|
default=None, help="filename of output graph")
|
|
options, args = opts.parse_args()
|
|
if len(args) != 0:
|
|
opts.error("Incorrect number of arguments")
|
|
|
|
# Draw graph
|
|
setup_matplotlib(options.output is not None)
|
|
fig = plot_motion()
|
|
|
|
# Show graph
|
|
if options.output is None:
|
|
matplotlib.pyplot.show()
|
|
else:
|
|
fig.set_size_inches(6, 2.5)
|
|
fig.savefig(options.output)
|
|
|
|
if __name__ == '__main__':
|
|
main()
|