Patent ID: 11860038
Assignee: GOOGLE LLC
Field: Control (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A method comprising:
detecting, with a passive infrared sensor (PIR), levels of infrared radiation in a field of view (FOV) of the PIR;
generating a signal based on the levels of infrared radiation detected with the PIR, the signal having values used to detect a change in the levels of infrared radiation as detected with the PIR;
extracting a local feature from a sample of the signal by tracking an absolute deviation of the sample of the signal relative to a threshold predetermined to approximate a non-environmental radiation source, wherein:
the local feature indicates a first probability that the non-environmental radiation source in the FOV caused the change in the detected levels of infrared radiation; and
the non-environmental radiation source corresponds to human motion;

extracting a global feature from the sample of the signal by a product of a feature parameter determined through training on a dataset to achieve a slow total variation and a rolling average value updated after every frame of the PIR, wherein the global feature indicates a second probability that an environmental radiation source caused the change in the detected levels of infrared radiation;
determining a score based on the local feature and the global feature; and
determining that the non-environmental radiation source has been detected in the FOV based on the score.