METHOD AND SYSTEM FOR DETERMINING THE POSITION OF AT LEAST ONE OBJECT

Abstract

The invention relates to a method and a system for position determination of at least one object, in particular inside a building. In a method for position determination of at least one object, at least four transmitters transmit circularly polarized signals and a receiver to be localized receives the circularly polarized signals. At least two and in particular all transmitters transmit periodic signals of different frequencies, these frequencies being closely adjacent.

Claims

1. A method for position determination of at least one object, in particular inside a building, in which at least four transmitters transmit circularly polarized signals and a receiver to be localized receives the circularly polarized signals, wherein at least two transmitters transmit periodic signals of different frequencies, these frequencies being closely adjacent.

2. The method according to claim 1, wherein the closely adjacent frequencies are less than one bandwidth of the transmitted signals apart.

3. The method according to claim 1, wherein the closely adjacent frequencies are less than a reciprocal period of the transmitted signals apart.

4. The method according to claim 1, wherein the closely adjacent frequencies are less than one quarter of a reciprocal period of the transmitted signals apart.

5. The method according to claim 1, wherein at least two and in particular all transmitters transmit signals in the frequency range between 3 GHz and 9 GHz.

6. The method according to claim 1, wherein at least two transmitters transmit the signals at mutually defined time intervals.

7. The method according to claim 1, wherein at least two transmitters transmit the signals simultaneously at least in time periods.

8. A system for position determination of at least one object, in particular inside a building, comprising at least four transmitters, each having a circularly polarized antenna, and a receiver to be localized, which has a circularly polarized antenna, wherein at least two transmitters are configured to transmit periodic signals of different frequencies, the frequencies of the respective transmitters being closely adjacent.

9. The system for position determination according to claim 8, wherein the circularly polarized antenna of at least one transmitter and/or receiver is arranged on a printed circuit board.

10. The system for position determination according to claim 8, wherein at least one circularly polarized antenna comprises a dielectric material and an annular conductor arranged on the dielectric material, wherein a planar conductor is arranged in the radial interior of the annular conductor, the planar conductor being spaced apart from the annular conductor and arranged on the dielectric material.

11. The system for position determination according to claim 8, wherein the receiver comprises for each transmitter a separate receiving section which is configured to receive the signals of the respective transmitter.

12. The system for position determination according to claim 10, wherein the dielectric material is a ceramic material.

13. The system for position determination according to claim 8, wherein all of the transmitters are configured to transmit periodic signals of different frequencies, the frequencies of the respective transmitters being closely adjacent.

14. The method according to claim 1, wherein the closely adjacent frequencies are one eighth of a reciprocal period of the transmitted signals apart.

15. The method according to claim 1, wherein at least two transmitters transmit signals in the frequency range between 4.5 GHz and 7.5 GHz.

16. The method according to claim 1, wherein at least two transmitters transmit signals in the frequency range between 5.5 GHz and 6.5 GHz.

17. The method according to claim 1, wherein all the transmitters transmit the signals at mutually defined time intervals.

18. The method according to claim 1, wherein all the transmitters transmit the signals simultaneously at least in time periods.

19. A method for position determination of at least one object, in particular inside a building, in which at least four transmitters transmit circularly polarized signals and a receiver to be localized receives the circularly polarized signals, wherein all transmitters transmit periodic signals of different frequencies, these frequencies being closely adjacent.

Description

[0056] FIG. 1: a perspective view of a first exemplary embodiment of a circularly polarized antenna;

[0057] FIG. 2: a partial top view of the circularly polarized antenna of FIG. 1; and

[0058] FIG. 3: a perspective view of a second exemplary embodiment of a circularly polarized antenna.

[0059] FIG. 1 shows a circularly polarized antenna 1 as part of a transmitter or receiver of a system according to the invention, which is designed for frequencies between 4 GHz and 8 GHz. This is arranged on a printed circuit board (not shown). The circularly polarized antenna 1 comprises a microstrip 5 made of copper, which is applied to the printed circuit board by means of printing and/or etching. The microstrip 5 has a width of 1 mm, a height of 35 μm and an electrical resistance of 50 ohms. The printed circuit board has a height of 0.5 mm or 0.6 mm and is produced from a hardly inflammable and flame-retardant composite material, in particular of class FR-4.

[0060] On the printed circuit board as well as on a front area of the microstrip 5 shown on the right is the dielectric material 2, which has the shape of a circular cylinder. The longitudinal axis of the circular cylinder-shaped dielectric material 2, which extends from top to bottom, is aligned perpendicular to the printed circuit board. The dielectric conductor 2 is produced from ceramic material comprising Al.sub.2O.sub.3 having a height of 2.5 mm and a diameter of 6 mm or 6.5 mm. It has a permittivity of 30.

[0061] On the upper side of the dielectric material 2, the annular conductor 3 is arranged, which consists of a copper layer with a height of 35 μm. It is annular-ring shaped, wherein the outer diameter of the annular ring corresponds to the diameter of the circular cylinder of the dielectric material 2.

[0062] The planar conductor 4 is arranged in the plane of the annular conductor 3 and in the radial interior of the annular conductor 3. It has the shape of a quarter circle and is also designed as a copper layer with a height of 35 μm. In the axial viewing direction, it is arranged in the region of the dielectric material 2 facing away from the microstrip 5 in such a way that its right-angled corner point, which would correspond to the center of the associated circle, is located on the longitudinal axis of the circular cylindrical dielectric material 2. The axial viewing direction refers to the longitudinal axis of the dielectric material and/or the annular conductor. This arrangement defines the desired polarization rotation direction of the circularly polarized antenna 1.

[0063] In another configuration, the diameter of the dielectric material 2, which is also circular cylindrical, may be 10 mm. The height of the dielectric material 2 may be 3 mm. The dielectric material 2 may have a permittivity of 10. In another configuration, the dielectric material 2 may have a height of 2.3 mm and a diameter of 6.1 mm.

[0064] FIG. 2 shows the same circularly polarized antenna in a partially cut top view with axial viewing direction. The annular conductor 3, in the radial interior of which the dielectric material 2 is visible, the planar conductor 4 and the section of the microstrip 5 outside the annular conductor 3 are shown. The section of the microstrip 5 inside the annular conductor 3, which is usually hidden by the dielectric material 2 in the uncut top view, is shown in finer hatching in this partially cut view. It can thus be seen that the microstrip 5 continues underneath the dielectric material 2, projects beyond the annular conductor 3 when viewed in the axial direction, and is extended to such an extent that the end of the microstrip 5 is at a distance of approximately 0.5 mm from the planar conductor 4.

[0065] The circular arc of the planar conductor 4 is parallel to the adjacent circular arc defined by the inner side of the annular conductor 3. In other words, the two circular arcs are parallel curves. This means that in each case two points located on a radially extending straight line, one point of which lies on the circular arc of the planar conductor 4 and the other point of which lies on the circular arc of the inside of the annular conductor 3, have the same distance. The distance measured in the radial direction between the circular arc of the planar conductor 4 and the circular arc defined by the inside of the annular conductor 3 is 0.5 mm.

[0066] FIG. 3 shows a circularly polarized antenna 1 which has the same elements as the circularly polarized antenna 1 shown in FIGS. 1 and 2. The only difference consists in the arrangement of the planar conductor 4 in the radial interior of the annular conductor 3. This is arranged in an axisymmetrically mirrored manner when viewed axially compared to its arrangement in the configuration shown in FIGS. 1 and 2. The axis along which the mirroring takes place is the longitudinal direction of extension of the microstrip 5. In this way, an opposite polarization rotation direction results.

LIST OF REFERENCE SIGNS

[0067] Circularly polarized antenna 1 [0068] Dielectric material 2 [0069] Annular conductor 3 [0070] Planar conductor 4 [0071] Microstrip 5