FFT vs Welch vs STFT: 10Hz Bearing Speed Benchmark

A benchmark compared FFT, Welch's method, and STFT on a 10-second vibration signal for bearing fault detection under 100ms latency. FFT was fastest (0.8ms) but too noisy, Welch (2.7ms) revealed the 162 Hz BPFI modulation, and STFT (5.1ms) captured fault amplitude changes during load transitions. The test used a MEMS accelerometer on a $40 bearing rig sampled at 10 kHz, targeting real-time operation on a Raspberry Pi 4.