Method and system for the remote monitoring of the two/three-dimensional field of displacements and vibrations of objects/structures

Patent metadata

Field	Value
Publication number	US-9927514-B2
Application number	US-201514694139-A
Country	US
Kind code	B2
Filing date	Apr 23, 2015
Priority date	Apr 24, 2014
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

A method and system for remote monitoring of a two/three-dimensional field of displacements and vibrations of an object, the method including transmitting of a plurality of radar waves by a plurality of corresponding radar devices positioned at a predefined distance from a plurality of corresponding receiver devices applied on the object, obtaining a first distance value between each radar device and the corresponding receiver or target device, the first distance value being affected by an error consisting of the sum between an electromagnetic propagation disturbance in the atmosphere of the radar waves and a reciprocal interference between the single receiver or target devices and one or more fixed reflectors positioned in the proximity of the receiver devices, and obtaining, simultaneously with respect to the first distance value, a second distance value between each radar device and a plurality of corresponding calibration devices positioned at predefined distances from said radar devices.

First claim

The invention claimed is:

1. A method for the remote monitoring of a two/three-dimensional field of displacements and vibrations of an object/structure, the method comprising the following steps:
transmitting a plurality of radar waves by a plurality of corresponding radar devices (R k ) placed at a predefined distance from a plurality of corresponding receiver or target devices (T n ) applied on the object/structure;
obtaining a first distance value (R LOS (R k ,T n )) between each radar device (R k ) and the corresponding receiver or target device (T n ), wherein said first distance value (R LOS (R k ,T n )) is affected by the sum of electromagnetic propagation disturbance in the atmosphere (d aps ) of the radar waves and an error (w n,k (t)) due to reciprocal interference between the single receiver or target devices (T n ) and one or more fixed reflectors positioned in the proximity of said receiver or target devices (T n );
obtaining, simultaneously with respect to the first distance value (R LOS (R k ,T n )), a second distance value (R LOS (R k ,C p )) between each radar device (R k ) and a plurality of corresponding calibration devices (C p ) placed at predefined distances from said radar devices (R k ), wherein said second distance value (R LOS (R k ,C p )) is affected only by electromagnetic propagation disturbance in the atmosphere (d aps ) of the radar waves;
estimating and removing the contribution of the electromagnetic propagation disturbance in the atmosphere (d aps ) of the radar waves to obtain a second corrected distance value;
estimating and removing the error (w n,k (t)) due to the reciprocal interference between the single receiver or target devices (T n ) and one or more fixed reflectors positioned in the proximity of said receiver or target devices (T n ), to obtain a first corrected distance value, said first corrected distance value defining the entity of the spatial displacement of the object/structure.

2. The method according to claim 1 , wherein the transmitting step is performed by two or more radar devices (R 1 , R 2 , R 3 ) operating in a monostatic and time division configuration, which means that each radar device (R 1 , R 2 , R 3 ) transmits and receives its own radar signal, said radar devices (R 1 , R 2 , R 3 ) being synchronized with each other by means of an external reference system to avoid reciprocal interference, wherein each radar device (R 1 , R 2 , R 3 ) is configured for measuring physical points of the object/structure positioned at different distances from the respective radar devices (R 1 , R 2 , R 3 ) and wherein said physical points are equipped with two or more respective receiver or target devices (T 1 , T 2 , T 3 ).

3. The method according to claim 2 , wherein the first distance value (R LOS (R k ,T n )) between each radar device (R k ) and the corresponding receiver or target device (T n ) is given by the equation:

R
LOS

⁡

(

R
k

,

T
n

)

+

Δ
⁢

⁢

R
LOS

⁡

(

t
,

R
k

,

T
n

)

=

ψ

n
,
k

⁡

(
t
)

4
⁢
π

⁢

c
0

f
0

+

d
aps

⁡

(

t
,

R
k

,

T
n

)

+

w

n
,
k

⁡

(
t
)

wherein ΔR LOS (t,R k ,T n ) represents a vibratory motion as a function of time of the k-th radar device (R k ) and ψ n,k represents the measurement of the phase of the signal received from the n-th receiver or target device (T n ) and the k-th radar device (R k ).

4. The method according to claim 3 , wherein the estimation and removal step of the contribution of the electromagnetic propagation disturbance in the atmosphere (d aps ) of the radar waves envisages the approximation of said electromagnetic propagation disturbance in the atmosphere (d aps ) of the radar waves as a constant term and a linear term with the distance, characterizing it, for each time value, by a pair of parameters according to the equation:
d aps ( t,R k ,C p )≈ k 0 ( t )+ k 1 ( t ) R LOS ( R k ,C p ).

5. The method according to claim 4 , wherein the second distance value (R LOS (R k ,C p )) between each radar device (R k ) and the corresponding calibration device (C p ) is given by the equation:

R
LOS

⁡

(

R
k

,

C
p

)

=

Assignees

• Eni Spa

Inventors

• Giunta Giuseppe
• Monti-Guarnieri Andrea

Classifications

• G01S7/023

  Interference mitigation, e.g. reducing or avoiding non-intentional interference with other HF-transmitters, base station transmitters for mobile communication or other radar systems, e.g. using electro-magnetic interference [EMI] reduction techniques (auxiliary means for detecting or identifying radar signals or the like G01S7/021; means for anti-jamming G01S7/36) · CPC title

• G01S13/87

  Combinations of radar systems, e.g. primary radar and secondary radar · CPC title

• G01S2007/4095

  Physics · mapped topic

• G01S7/354

  Extracting wanted echo-signals (Doppler systems G01S13/50) · CPC title

• G01S13/58

  Velocity or trajectory determination systems; Sense-of-movement determination systems · CPC title