Radar detection system

Patent metadata

Field	Value
Publication number	US-2019346550-A1
Application number	US-201816475893-A
Country	US
Kind code	A1
Filing date	Jan 5, 2018
Priority date	Jan 6, 2017
Publication date	Nov 14, 2019
Grant date	—

Abstract

A radar presence detection system is configured to detect oscillations within a building. The radar presence detection system includes an accelerometer, a radar, and a processing unit. The accelerometer is attached to the building and configured to detect structural vibration waves. The radar is configured to transmit a monitoring wave and receive a reflected wave. The processing unit includes a filter, an adaptive filter, and a detector. The filter is configured to receive a first signal indicative of the reflected wave and output a filtered reflected wave signal spanning a frequency range indicative of an oscillation within the building. The adaptive filter is configured to receive a second signal indicative of the structural vibration wave signal and output a focused vibration signal spanning a frequency range for the cancellation of vibration noise.

First claim

What is claimed is:

1 . A radar presence detection system configured to detect oscillations within a building, the radar detection system comprising:
an accelerometer attached to the building and configured to detect structural vibration waves; a radar configured to transmit a monitoring wave and receive a reflected wave; and a processing unit configured to receive a reflected wave signal from the radar indicative of the reflected wave, and a vibration wave signal indicative of the structural vibration wave, the processing unit including a filter, an adaptive filter and a detector, wherein the filter is configured to receive a first signal indicative of the reflected wave signal and output a filtered reflected wave signal spanning a frequency range indicative of an oscillation within the building, and the adaptive filter being configured to receive a second signal indicative of the structural vibration wave signal and output a focused vibration signal spanning the frequency range for the cancellation of vibration noise, and wherein the detector is configured to receive a third signal indicative of at least the filtered reflected wave signal and output an oscillation signal indicative of at least the detection of the oscillation.

2 . The radar presence detection system set forth in claim 1 , wherein the processing unit is a vital sign processing unit, the filtered reflected wave signal is a vital sign reflected wave signal, and the oscillation is a vital sign; and, wherein the vital sign processing unit includes a summation module configured to receive the vital sign reflected wave signal and the focused vibration signal, subtract the focused vibration signal from the vital sign reflected wave signal, and output a corrected vital sign signal received by the detector.

3 . The radar presence detection system set forth in claim 1 , wherein the adaptive filter is a long adaptive filter.

4 . The radar presence detection system set forth in claim 1 , wherein the processing unit is a vital sign processing unit and the oscillation is a vital sign, and the vital sign processing unit includes a first analog-to-digital converter configured to receive the reflected wave signal and output a digitized reflected wave signal as the first signal.

5 . The radar presence detection system set forth in claim 4 , wherein the vital sign processing unit includes a second analog-to-digital converter configured to receive the vibration wave signal and output a digitized vibration signal as the second signal.

6 . The radar presence detection system set forth in claim 5 , wherein the filtered reflected wave signal is a vital sign reflected wave signal, and wherein the vital sign processing unit includes a summation module configured to receive the vital sign reflected wave signal and the focused vibration signal, subtract the focused vibration signal from the vital sign reflected wave signal, and output a corrected vital sign signal received by the detector.

7 . The radar presence detection system set forth in claim 3 , wherein the adaptive filter is configured to cancel a broad band of vibration frequencies within the frequency range.

8 . The radar presence detection system set forth in claim 7 , wherein the adaptive filter includes a plurality of taps with a sufficient number of taps so that a full wave at a minimum respiration frequency is accommodated.

9 . The radar presence detection system set forth in claim 1 , wherein the oscillation is at least one vital sign that includes at least one of a respiration rate and a heartbeat.

10 . The radar presence detection system set forth in claim 1 , wherein the radar is remotely located from the accelerometer.

11 . The radar presence detection system set forth in claim 1 further comprising:
an actuator attached to the building and the accelerometer, wherein the actuator receives and is driven by the focused vibration signal to cancel vibration noise.

12 . The radar presence detection system set forth in claim 1 , wherein the adaptive filter is at least one of a LMS filter, a NLMS filter, a RLS filter, and a DMI filter.

13 . The radar presence detection system set forth in claim 1 , wherein the accelerometer is not located at any vibration node of the building.

14 . The radar presence detection system set forth in claim 11 , wherein the accelerometer is co-located with the radar.

15 . The radar presence detection system set forth in claim 1 , wherein the accelerometer is a three-axis accelerometer.

16 . A method of operating a radar presence detection system comprising:
transmitting a monitoring wave by a transceiver of a radar; receiving a reflected wave by the transceiver; sending a reflected wave signal indicative of the reflected wave and by the radar to a processing unit; filtering a digitized reflected wave signal associated with the reflected wave signal by a filter of the processing unit to cancel a broadband of frequencies not within a targeted oscillation frequency range; outputting an oscillation reflected wave signal associated with the digitized reflected wave signal by the filter; detecting building vibrations by an accelerometer; sending a building vibration wave signal by the accelerometer to a second analog-to-digital converter of the processing unit; filtering a digitized vibration signal associated with the vibration wave signal by an adaptive filter of the processing unit to cancel a broadband of frequencies within the targeted oscillation frequency range; outputting a focused vibration signal associated with the digitized vibration signal by the adaptive filter; receiving the oscillation reflected wave signal and the focused vibration signal by a summation module; subtracting the focused vibration signal from the oscillation reflected wave signal; sending a corrected oscillation signal by the summation module to a detector; and evaluating the corrected oscillation signal by the detector to determine a presence.

17 . The method set forth in claim 16 , wherein the processing unit is a vital sign processing unit, the targeted oscillation frequency range is a vital sign frequency range, the oscillation reflected wave signal is a vital sign reflected wave signal, the corrected oscillation signal is a corrected vital sign signal.

18 . The method set forth in claim 17 , wherein the presence is a human presence.

19 . The method set forth in claim 16 further comprising:
computing a transfer function by the adaptive filter associated with the location of the accelerometer relative to the radar.

20 . The method set forth in claim 16 , wherein the reflected wave signal is sent to a first analog-to-digital converter of the vital sign processing unit.

Assignees

• Carrier Corp

Inventors

• Finn Alan Matthew
• Soldner Nicholas Charles
• Zacchio Joseph
• Xiong Ziyou
• Tokgoz Cagatay

Classifications

• A61B5/0205

  Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition · CPC title

• G01S13/86 Primary

  Combinations of radar systems with non-radar systems, e.g. sonar, direction finder · CPC title

• A61B5/0507

  using microwaves or terahertz waves · CPC title

• A61B5/0816

  Measuring devices for examining respiratory frequency (measuring frequency of electric signals G01R23/00) · CPC title

• G01S13/56 Primary

  for presence detection {(presence detection using near field arrangements G01V3/00, e.g. G01V3/08, G01V3/12; burglar, theft or intruder alarms with electrical actuation G08B13/22 - G08B13/26)} · CPC title