58 lines
2.4 KiB
Python
58 lines
2.4 KiB
Python
"""Calculate the time for each stroke and then the SPM."""
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nameplate_hz = 120.0
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nameplate_rpm = 1200.0
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approach_freq = 20
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total_stroke_length = 60
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offset_top = 2
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offset_bottom = 2
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accel_time = 2.0
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decel_time = 2.0
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thread_pitch = 0.5906
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def time_for_freq_change(freq_delta, np_hz, ramp_time):
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"""Calculate the time required for a frequency change."""
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return (freq_delta / np_hz) * ramp_time
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def dist_for_freq_change(freq_delta, ramp_time, np_hz, np_rpm, thread_pitch):
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"""Calculate the distance required for a frequency change."""
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time_required = time_for_freq_change(freq_delta, np_hz, ramp_time)
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return 0.75 * freq_delta * (np_rpm / np_hz) * (1.0 / 60.0) * time_required * thread_pitch
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def time_for_uniform_freq(freq, distance, np_hz, np_rpm, thread_pitch):
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"""Calculate the time required to move a distance at a frequency."""
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return distance / (freq * (np_rpm / np_hz) * (1.0 / 60.0) * thread_pitch)
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def calculate_stroke_time(stroke_length, upper_offset, lower_offset, run_frequency, ramp_frequency, accel_time, decel_time):
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"""Calculate the time it takes to make a full stroke."""
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ramp_up_time = time_for_freq_change(run_frequency, nameplate_hz, accel_time)
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ramp_up_dist = dist_for_freq_change(run_frequency, accel_time, nameplate_hz, nameplate_rpm, thread_pitch)
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ramp_down_time = time_for_freq_change(run_frequency - ramp_frequency, nameplate_hz, decel_time)
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ramp_down_dist = dist_for_freq_change(run_frequency - ramp_frequency, decel_time, nameplate_hz, nameplate_rpm, thread_pitch)
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turn_time = time_for_freq_change(ramp_frequency, nameplate_hz, decel_time)
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turn_dist = dist_for_freq_change(ramp_frequency, decel_time, nameplate_hz, nameplate_rpm, thread_pitch)
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run_dist = total_stroke_length - (offset_bottom + offset_top + ramp_up_dist + ramp_down_dist + turn_dist)
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run_time = time_for_uniform_freq(run_frequency, run_dist, nameplate_hz, nameplate_rpm, thread_pitch)
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stroke_time = 2.0 * (ramp_up_time + run_time + ramp_down_time + turn_time)
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return stroke_time
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for ramp_i in [0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0]:
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print("-----")
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print("Ramp Rate: {}".format(ramp_i))
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for hz_i in [20.0, 30.0, 40.0, 50.0, 60.0, 70.0, 80.0, 90.0, 100.0, 110.0, 120.0]:
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spm = 60 / calculate_stroke_time(total_stroke_length, offset_top, offset_bottom, hz_i, approach_freq, ramp_i, ramp_i)
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print("Freq: {} Hz., SPM: {}".format(hz_i, spm))
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