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

Claim 8:
9. A passive infrared (PIR) sensor device, comprising:
a plurality of radiation sensitive elements that detect radiation levels in a field of view (FOV) and generate charges based on the radiation levels;
a circuit that receives the generated charges and generates a single output signal based on the charges; and
a processor that receives the signal and extracts 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 and 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, the local feature indicating a first probability that the non-environmental radiation source in the FOV caused a change in the detected radiation levels and the global feature indicating a second probability that an environmental radiation source in the FOV caused the change in the detected radiation levels, wherein the non-environmental radiation source corresponds to human motion;
wherein the processor is configured:
to determine a score based on the global feature and the local feature, and
to determine that the non-environmental radiation source has been detected in the FOV based on the score.