Search International and National Patent Collections

1. (WO2018146454) MOTION DETECTOR

Pub. No.:    WO/2018/146454    International Application No.:    PCT/GB2018/050265
Publication Date: Fri Aug 17 01:59:59 CEST 2018 International Filing Date: Wed Jan 31 00:59:59 CET 2018
IPC: G01S 15/52
G01S 7/527
Applicants: CIRRUS LOGIC INTERNATIONAL SEMICONDUCTOR LIMITED
Inventors: LAL, Anil
Title: MOTION DETECTOR
Abstract:
An ultrasonic motion activity detector is configured to, in each of a series of frames: obtain an ultrasonic signal derived from a transmitted ultrasonic signal; derive an activity signal based on a difference between the obtained signal in a present frame and at least one previous frame; determine a peak value of the activity signal in a first time window of the frame; determine a peak value of the activity signal in a second time window of the frame, wherein the first time window is different from the second time window; calculate a ratio of the peak value of the activity signal in the first time window of the frame to the peak value of the activity signal in the second time window of the frame; and compare the calculated ratio with a threshold value, and, in frames in which the calculated ratio exceeds the threshold value, determine that there is motion of an object relative to the detector.