Lights-Out Sentinel: Human-vs-Robot Discrimination

A walking human stirs the WiFi field with a messy, rhythmic pattern — swinging arms, stepping legs, and always breathing. A wheeled robot glides at constant speed with a clean motor hum and no breath at all. The system tells the two apart, so robots stop drowning the alarms.

In the physics: Human micro-Doppler is broadband and quasi-periodic (limb swing 1-3Hz with harmonics, gait cadence) and always carries a 0.1-0.5Hz breathing component; wheeled robots produce narrowband, constant-velocity Doppler with motor-vibration lines and zero respiration — separable signatures in the 0.1-40Hz band.