order op• 数据种类:signal → table
• 调用:import acoustics; acoustics.angular_resample(x, rate, rpm, samples_per_rev=64)(或 opsacoustics.get("angular_resample"))
把时间记录重采样到轴角轴上(计算阶次跟踪)。
> 以下的详细说明为原文 —— 摘要与标题已翻译。
Under a changing shaft speed, a component locked to the shaft has a moving
frequency and smears across the spectrum, while a structural resonance stays
put. Resample the record so the samples are equally spaced in shaft angle
instead of in time and the situation reverses exactly: the order becomes a
single line and the resonance smears.
`rpm` is either a single number (constant speed — the transform is then a
pure rescaling) or a per-sample array on the same clock as the signal. The
cumulative revolution count is the trapezoidal integral of `rpm/60`, and
the signal is linearly interpolated onto a uniform grid in it.
Returns a dict — an angle-domain record is not put into circulation as a
plain signal, deliberately. Its samples are indexed by angle, not time, so
handing it to any op that takes a `rate` would produce frequencies in Hz
from an axis measured in revolutions: no exception, no NaN, just wrong
numbers. (Same judgement, and the same reason, as `motionmag.motion_magnify`
not exposing a bare video adapter.) The dict carries `signal`,
`angle_rev, samples_per_rev, revolutions` (total),
`whole_revolutions, rate` (the original time-domain one, for
provenance), `mean_rpm, max_order`.
`max_order is samples_per_rev / 2` — the Nyquist of the *angle* axis.
Measured: a pure order-3.5 component on a 600 -> 1800 rpm ramp, resampled at
64 samples/rev over 78 whole revolutions, reads amplitude 0.999371 in a
single bin of the order spectrum; the same component in the ordinary
spectrum peaks at 0.070203 and is 66.5 Hz wide.
Raises `ValueError: everything :func:_as_signal` refuses, a
non-positive or wrong-length `rpm, samples_per_rev` outside
`[2, 65536], an output over :data:MAX_ANGULAR_SAMPLES`, fewer than one
complete revolution in the record, and — the aliasing refusal — a
`samples_per_rev` whose implied Nyquist order needs content above the
time-domain Nyquist. Asking for 64 samples/rev on a shaft turning at 30 Hz
means representing 960 Hz, which a 100 Hz recording does not contain; the
resampler would happily manufacture it from the interpolation.
• acoustic_condition_monitoring 族使用指南
• 示例数据目录(下载 URL / 许可证) —— 2-D 用 skimage.data(BSD/公有领域)加合成图,3-D 给出真实数据源(Stanford/PDS 等)的下载 URL。
• 算子来历与参考文献 —— 该算子族所依据的研究/方法出处。
• 算法的正典(作者・年份)与用途见上面的族使用指南。
• acoustic_condition_monitoring — py -3.11 examples/acoustic_condition_monitoring.py
table 作为输入)order)*Provenance: acoustics.py — ACOUSTICS 算子登记表。本条目由 tools/opdocs.py md 自动生成(请勿手工编辑)。*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.