A method and system for 3d position estimation of an object using time of arrival measurements

Patent metadata

Field	Value
Publication number	US-2016247392-A1
Application number	US-201414435942-A
Country	US
Kind code	A1
Filing date	Oct 27, 2014
Priority date	Oct 27, 2014
Publication date	Aug 25, 2016
Grant date	—

Abstract

A system and associated methodology determines the 3D position of an object using time of arrival measurements. In one embodiment, the system uses four stations to receive a transmitted or reflected signal from the object. The system finds the required coordinate component while minimizing the computational requirement.

First claim

1 . A method for determining a 3D position of an object, the method comprising:
receiving, from a first station, a first time of arrival of a signal; receiving, from a second station, a second time of arrival of the signal; receiving, from a third station, a third time of arrival of the signal; receiving, from a fourth station, a fourth time of arrival of the signal; calculating a first range measurement based on the first time of arrival and a signal propagation speed in a media; calculating a second range measurement based on the second time of arrival and the signal propagation speed in the media; calculating a third range measurement based on the third time of arrival and the signal propagation speed in the media; calculating a fourth range measurement based on the fourth time of arrival and the signal propagation speed in the media; determining, using processing circuitry and with reduced computation time, the 3D position of the object as a function of the first range measurement, the second range measurement, the third range measurement, the fourth range measurement, and positions of the first, second, third and fourth stations; and sending the 3D position of the object to an external device to provide enhanced accurate position data to host applications.

2 . The method of claim 1 , wherein the 3D position of the object is defined by x, y and z coordinates.

3 . The method of claim 1 , further comprising:
calculating the x coordinate as a function of I 1 , I 2 , I 3 , I 4 , I 5 and I 6
where
I 1 =(z 3 −z 1 )(x 2 −x 1 )−(z 2 −z 1 )(x 3 −x 1 ),
I 2 =(z 4 −z 1 )(x 2 −x 1 )−(z 2 −z 1 )(x 4 −x 1 ),
I 3 =(z 3 −z 1 )A 1 −(z 2 −z 1 )A 2 ,
I 4 =(z 4 −z 1 )A 1 −(z 2 −z 1 )A 3 ,
I 5 =(z 3 −z 1 )(y 2 −y 1 )−(z 2 −z 1 )(y 3 −y 1 ),
I 6 =(z 4 −z 1 )(y 2 −y 1 )−(z 2 −z 1 )(y 4 −y 1 ),
A 1 =(r 1 2 −r 2 2 )+(x 2 2 −x 1 2 )+(y 2 2 −y 1 2 )+(z 2 2 −z 1 2 ),
A 2 =(r 1 2 −r 3 2 )+(x 3 2 x 1 2 )+(y 3 2 y 1 2 )+(z 3 2 −z 1 2 ),
A 3 =(r 1 2 −r 4 2 )+(x 4 2 −x 1 2 )+(y 4 2 −y 1 2 )+(z 4 2 −z 1 2 ),
r 1 is the first range measurement, r 2 is the second range measurement, r 3 is the third range, measurement and r 4 is the fourth range measurement,
x 1 , y 1 , z 1 are coordinates defining the 3D position of the first station,
x 2 , y 2 , z 2 are the coordinates defining the 3D position of the second station,
x 3 , y 3 , z 3 are the coordinates defining the 3D position of the third station, and
x 4 y 4 , z 4 are the coordinates defining the 3D position of the fourth station.

4 . The method of claim 3 , wherein calculating the x coordinate includes applying

x
=

1
2



I
4



I
5

-

I
3



I
6

I
2



I
5

-

I
1



I
6

.

5 . The method of claim 3 , further comprising:
calculating the y coordinate as a function of I 1 , I 2 , I 3 , I 4 , I 5 and I 6 .

6 . The method of claim 5 , wherein calculating the y coordinate includes applying

y
=

1
2



I
1



I
4

-

I
2



I
3

I
1



I
6

-

I
2



I
5

.

7 . The method of claim 1 , further comprising:
calculating the z coordinate as a function of I 7 , I 8 , I 9 , I 10 , I 11 and I 12 ,
where
I 7 =(y 3 −y 1 )(x 2 −x 1 )−(y 2 −y 1 )(x 3 −x 1 ),
I 8 =(y 4 −y 1 )(x 2 −x 1 )−(y 2 −y 1 )(x 4 −x 1 ),
I 9 =(y 3 −y 1 )A 1 −(y 2 −y 1 )A 2 ,
I 10 =(y 4 −y 1 )A 1 −(y 2 −y 1 )A 3 ,
I 11 =(y 3 −y 1 )(z 2 −z 1 )−(y 2 −y 1 )(z 3 −z 1 ), and
I 12 =(y 4 −y 1 )(z 2 −z 1 )−(y 2 −y 1 )(z 4 −z 1 ).

8 . The method of claim 7 , wherein calculating the z coordinate includes applying

z
=

1
2



I
7



I
10

-

I
8



I
9

Assignees

• Univ Umm Al Qura

Inventors

• Khalaf-Allah Mohamed

Classifications

• G08C21/00 Primary

  Systems for transmitting the position of an object with respect to a predetermined reference system, e.g. tele-autographic system · CPC title

• H04B10/071

  using a reflected signal, e.g. using optical time domain reflectometers [OTDR] · CPC title

• H04W4/02

  Services making use of location information · CPC title

• G01S5/14 Primary

  Determining absolute distances from a plurality of spaced points of known location · CPC title

• G01S13/74

  Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems · CPC title