 (11)  EP 3 236 699 A1 
(12)  EUROPEAN PATENT APPLICATION 



 
(54)  POSITION ACQUISITION METHOD AND APPARATUS 
(57) The present application discloses a position acquisition method and a position acquisition apparatus. The method includes: selecting at least one group of N effective devices from known devices that transmit signals to a target device or known devices that receive signals transmitted by the target device; adjusting a numerical value of a conversion scaling factor with respect to each group of N effective devices, and seeking a corrected value of the conversion scaling factor, the corrected value enabling N circles or spheres formed by taking a position of each effective device as a center and a corrected distance between each effective device and the target device as a radius to have a unique intersection; wherein the conversion scaling factor is used to convert a signal intensity of the signal transmitted by the effective device towards the target device or the received signal transmitted by the target device into a distance; and calculating and acquiring a position of the target device by using at least one corrected value of the conversion scaling factor acquired. Position acquisition accuracy is improved through the embodiments of the present application.

TECHNICAL FIELD
BACKGROUND
SUMMARY
selecting at least one group of N effective devices from known devices that transmit signals to a target device or known devices that receive signals transmitted by the target device;
adjusting a numerical value of a conversion scaling factor with respect to each group of N effective devices, and seeking a corrected value of the conversion scaling factor, the corrected value enabling N circles or spheres formed by taking a position of each effective device as a center and a corrected distance between each effective device and the target device as a radius to have a unique intersection, wherein, the conversion scaling factor is used to convert a signal intensity of the signal transmitted by the effective device towards the target device or the received signal transmitted by the target device into a distance; and
calculating and acquiring a position of the target device by using at least one corrected value of the conversion scaling factor acquired.
a device selection module configured to select at least one group of N effective devices from known devices that transmit signals to a target device or known devices that receive signals transmitted by the target device;
a correction module configured to adjust a numerical value of a conversion scaling factor with respect to each group of N effective devices, and seek a corrected value of the conversion scaling factor, the corrected value enabling N circles or spheres formed by taking a position of each effective device as a center and a corrected distance between each effective device and the target device as a radius to have a unique intersection, wherein, the conversion scaling factor is used to convert a signal intensity of the signal transmitted by the effective device towards the target device or the received signal transmitted by the target device into a distance; and
a position acquisition module configured to calculate and acquire a position of the target device by using at least one corrected value of the conversion scaling factor acquired.
selecting at least one group of N effective devices from known devices that transmit signals to a target device or known devices that receive signals transmitted by the target device; adjusting a numerical value of a conversion scaling factor with respect to each group of N effective devices, and seeking a corrected value of the conversion scaling factor, the corrected value enabling N circles or spheres formed by taking a position of each effective device as a center and a corrected distance between each effective device and the target device as a radius to have a unique intersection, wherein, the conversion scaling factor is used to convert a signal intensity of the signal transmitted by the effective device towards the target device or the received signal transmitted by the target device into a distance; and calculating and acquiring a position of the target device by using at least one corrected value of the conversion scaling factor acquired. The embodiment of the present application improves the position acquisition accuracy of the target device by seeking the correction value of the conversion scaling factor, and reduces the problem that the position acquisition is inaccurate due to the signal intensity errors.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a flow chart of one embodiment of a position acquisition method of the embodiments of the present application;
Figs. 2a to 2k are schematic diagrams for position acquisition in a onedimensional coordinate space of the embodiments of the present application;
Figs. 3a to 3m are schematic diagrams for position acquisition in a twodimensional coordinate space of the embodiments of the present application;
Figs. 4a to 4c are schematic diagrams for position acquisition in a threedimensional coordinate space of the embodiments of the present application;
Fig. 5 is a schematic diagram of disposing known devices in an indoor environment in the embodiments of the present application;
Fig. 6 is a schematic diagram of selecting effective devices in the embodiments of the present application;
Fig. 7 is another schematic diagram of selecting effective devices in the embodiments of the present application; and
Fig. 8 is a structural schematic diagram of one embodiment of a position acquisition apparatus of the embodiments of the present application.
DETAILED DESCRIPTION
enlarging or reducing the numerical value of the conversion scaling factor from an initial value of the conversion scaling factor, and by taking a current adjusted value of the conversion scaling factor as the corrected value of the conversion scaling factor when the current adjusted value enables the N circles or spheres formed by taking the position of each effective device as the center and the corrected distance between each effective device and the target device as the radius to have the unique intersection.
(X1) Any effective device is selected from the N effective devices as a judgment device, and other N1 effective devices are taken as positioning devices.
(X2) N1 circles or spheres formed by taking a current distance between the N1 effective devices and the target device as a radius are judged whether to have an intersection and whether a current distance between the judgment device and the target device is equal to an intersection distance between the judgment device and an intersection position from by taking the initial value of the conversion scaling factor as the current adjusted value.
Wherein, the current distance is namely calculated and acquired by using a current adjusted value of the conversion scaling factor.
(X3) If the judgment result of (X2) is yes, then the current value of the conversion scaling factor is taken as the corrected value of the conversion scaling factor.
That is, if the N1 circles or spheres have intersection, and the current distance between the judgment device and the target device is equal to an intersection distance between the judgment device and any intersection position, then it represents that the N circles formed by taking the current distances between the positioning devices and the target device as well as the current distance between the judgment device and the target device as the radius respectively have the unique intersection, and the current value at this moment is namely taken as the corrected value.
(X4) If the judgment result of (X2) is no, i.e., the N1 circles or spheres have no intersection, or the current distance between the judgment device and the target device cannot be equal to the intersection distance between the judgment device and any intersection position, following operations are performed.
(X41) The current distance between the judgment device and the target device is compared with a first intersection distance between the judgment device and an intersection position close to the judgment device, a second intersection distance between the judgment device and an intersection position far from the judgment device, and a center distance between the judgment device and a central point of a connecting line of the two intersection positions respectively when the N1 circles or spheres have two intersection positions.
(X411) If the current distance is less than the first intersection distance and less than the center distance, or the current distance is less than the second intersection distance and greater than the center distance, the conversion scaling factor is enlarged.
(X412) If the current distance is greater than the first intersection distance and less than the center distance, or the current distance is greater than the second intersection distance and greater than the center distance, or the current distance is greater than the first intersection distance and equal to the center distance, and a current distance between the judgment device and the target device is equal to current distances between the positioning devices and the target device respectively, the conversion scaling factor is reduced.
(X413) If the current distance is equal to the center distance, and the current distance between the judgment device and the target device is unequal to the current distances between the positioning devices and the target device respectively, one effective device is selected as a judgment device and the other N1 effective devices are taken as positioning devices to perform continuously.
(X42) When the N1 circles or spheres have no intersections and are externally separated from each other, and the N1 circles or spheres are externally separated from a circle or sphere formed by taking the current distance between the judgment device and the target device as a radius respectively, and current distances between the N effective devices and the target device are equal, the conversion scaling factor is enlarged.
a position coordinate of the N effective devices is a onedimensional coordinate, N is equal to 2, and the N effective devices include two effective devices.
(A1) One effective device is selected from the N effective devices as a positioning device and the other is taken as a judgment device.
(A2) In the onedimensional coordinate space, only one positioning device is included, and only one circle is formed by taking the current distance between the positioning device and the target device as the radius. To facilitate description, the circle is named as a positioning circle.
At this moment, two intersection positions formed by a connecting line of the judgment device and the positioning device with the positioning circle are namely taken as the intersection position of the N1 circles.
Then in step (A2), whether the current distance between the judgment device and the target device is equal to the intersection distance between the judgment device and any intersection position is judged.
(A3) If the result of step (A2) is yes, then the current value is taken as the corrected value.
(A4) If the result of step (A3) is no, the current distance between the judgment device and the target device is compared with a first intersection distance between the judgment device and an intersection position close to the judgment device, a second intersection distance between the judgment device and an intersection position far from the judgment device, and a center distance between the judgment device and a central point of a connecting line of the two intersection positions respectively.
As shown in Figs. 2a to 2e, two circles are formed by the positioning device A and the judgment device B, the two intersection positions of the positioning device are respectively a and b, the intersection position a is the intersection position close to the judgment device, and the intersection position b is the intersection position far from the judgment device.
(A41) If the current distance is less than the first intersection distance and less than the center distance, the conversion scaling factor is enlarged, as shown in Fig. 2a; the current distance is enabled to be equal to the first intersection distance and intersected at the intersection position a by enlarging the conversion scaling factor, as shown in Fig. 2b.
(A42) If the current distance is less than the second intersection distance and greater than the center distance, the conversion scaling factor is enlarged, as shown in Fig. 2c. The current distance is enabled to be equal to the first intersection distance and intersected at the intersection position b by enlarging the conversion scaling factor, as shown in Fig. 2d.
(A43) If the current distance is greater than the first intersection distance and less than the center distance, the conversion scaling factor is reduced, as shown in Fig. 2e. The current distance is enabled to be equal to the first intersection distance and intersected at the intersection position a by reducing the conversion scaling factor, as shown in Fig. 2f.
(A44) If the current distance is greater than the second intersection distance and greater than the center distance, the conversion scaling factor is reduced, as shown in Fig. 2g. The current distance is enabled to be equal to the second intersection distance and intersected at the intersection position b by reducing the conversion scaling factor, as shown in Fig. 2h.
(A45) If the current distance is greater than the first intersection distance and equal to the center distance, and a current distance between the judgment device and the target device is equal to a current distance between the positioning device and the target device respectively, the conversion scaling factor is reduced, as shown in Fig. 2i; the current distance is enabled to be equal to the first intersection distance and intersected at the intersection position a by reducing the conversion scaling factor, as shown in Fig. 2j.
(A46) If the current distance is equal to the center distance, and the current distance between the judgment device and the target device is unequal to the current distance between the positioning device and the target device respectively, return to step (A1) to reselect one effective device as a judgment device and use the other effective devices as a positioning device to perform continuously; that is, roles of the positioning device and the judgment device are exchanged, as shown in Fig. 2k.
a position coordinate of the N effective devices is a twodimensional coordinate, and the N effective devices include three effective devices.
(B1) Any two effective devices are selected from the N effective devices as positioning devices and the other is taken as a judgment device.
(B2) Two circles formed by taking current distances between the positioning devices and the target device as a radius are judged whether to have an intersection and whether a current distance between the judgment device and the target device is equal to an intersection distance between the judgment device and an intersection position from by taking the initial value of the conversion scaling factor as the current adjusted value.
Wherein, the current distance is calculated and acquired by using a current value of the conversion scaling factor.
(B3) If the judgment result of (B2) is yes, i.e., the two circles formed by the positioning devices have intersection, and the current distance between the judgment device and the target device is equal to the intersection distance between the judgment device and any intersection position, the current value of the conversion scaling factor is taken as the corrected value of the conversion scaling factor at this moment.
(B4) If the judgment result of (B2) is no, then following operations are performed.
(B41) The current distance between the judgment device and the target device is compared with a first intersection distance between the judgment device and an intersection position close to the judgment device, a second intersection distance between the judgment device and an intersection position far from the judgment device, and a center distance between the judgment device and a central point of a connecting line of the two intersection positions respectively when the two circles have two intersection positions.
As described in Figs. 3a to 3j, the two circles formed by the two positioning devices have two intersection positions which are c and d respectively, wherein the intersection position c is an intersection position close to the judgment device C, and the distance from the judgment device C to the intersection position c is the first intersection distance; therefore, the distance from the judgment device C to the intersection position d is namely the second intersection distance, and the distance from the judgment device C to the central point m of the connecting line of c and d is the center distance.
(B411) If the current distance is less than the first intersection distance and less than the center distance, the conversion scaling factor is enlarged. As is shown in Fig. 3a. The current distance is enabled to be equal to the first intersection distance and the three circles are intersected at the intersection position c by enlarging the conversion scaling factor, as shown in Fig. 3b.
(B412) If the current distance is less than the second intersection distance and greater than the center distance, the conversion scaling factor is enlarged, as shown in Fig. 3c; the current distance is enabled to be equal to the second intersection distance and the three circles are intersected at the intersection position b by enlarging the conversion scaling factor, as shown in Fig. 3d.
(B413) If the current distance is greater than the first intersection distance and less than the center distance, the conversion scaling factor is reduced, as shown in Fig. 3e; the current distance is enabled to be equal to the first intersection distance and the three circles are intersected at the intersection position c by reducing the conversion scaling factor, as shown in Fig. 3f.
(B414) If the current distance is greater than the second intersection distance and greater than the center distance, the conversion scaling factor is reduced, as shown in Fig. 3g; the current distance is enabled to be equal to the second intersection distance and the three circles are intersected at the intersection position d by reducing the conversion scaling factor, as shown in Fig. 3h.
(B415) If the current distance is greater than the first intersection distance and equal to the center distance, and a current distance between the judgment device and the target device is equal to a current distance between the positioning device and the target device respectively, the conversion scaling factor is reduced, as shown in Fig. 3i; the current distance is enabled to be equal to the first intersection distance and the three circles are intersected at the intersection position c by enlarging the conversion scaling factor.
(B416) If the current distance is equal to the center distance, and the current distance between the judgment device and the target device is unequal to the current distances between the positioning devices and the target device respectively, one effective device is reselected as a judgment device and the other two effective devices are taken as positioning devices to perform continuously, as shown in Fig. 3j.
(B42) When the two circles have no intersections and the two circles are externally separated from the circle or sphere formed by taking the current distance between the judgment device and the target device as the radius, and current distances between the three effective devices and the target device are equal, the conversion scaling factor is enlarged.
a position coordinate of the N effective devices is a threedimensional coordinate, and the N effective devices include four effective devices.
(C1) Any three effective devices are selected from the N effective devices as positioning devices and the other is taken as a judgment device.
(C2) Three spheres formed by taking current distances between the positioning devices and the target device as a radius are judged whether to have an intersection and whether a current distance between the judgment device and the target device is equal to an intersection distance between the judgment device and an intersection position from by taking the initial value of the conversion scaling factor as the current adjusted value.
Wherein, the current distance is calculated and acquired by using a current value of the conversion scaling factor.
Wherein, the three spheres in the threedimensional coordinate space have intersections, wherein three spheres are externally tangent, as shown in Fig. 4a; three spheres are intersected, as shown in Fig. 4b; and three spheres are internally tangent, as shown in Fig. 4c.
When three spheres are externally tangent or internally tangent, the three spheres have one intersection.
When three spheres are intersected, the three spheres have two intersections.
(C3) If all the judgment results of (C2) are yes, i.e., the three spheres formed by the positioning devices have intersection, and the current distance between the judgment device and the target device is equal to the intersection distance between the judgment device and any intersection position, the current value of the conversion scaling factor is taken as the corrected value of the conversion scaling factor at this moment.
(C4) If the judgment result of (C2) is no, then following operations are performed.
(C41) The current distance between the judgment device and the target device is compared with a first intersection distance between the judgment device and an intersection position close to the judgment device, a second intersection distance between the judgment device and an intersection position far from the judgment device, and a center distance between the judgment device and a central point of a connecting line of the two intersection positions respectively when the N1 circles or spheres have two intersection positions.
Wherein, in the threedimensional coordinate space, the center distance between the judgment device and the central point of the connecting line of the two intersection positions specifically refer to a center distance of a plane formed from the judgment device and the central point of the connecting line of the two intersection positions.
(C411) If the current distance is less than the first intersection distance and less than the center distance, the conversion scaling factor is enlarged.
(C412) If the current distance is less than the second intersection distance and greater than the center distance, the conversion scaling factor is enlarged.
(C413) If the current distance is greater than the first intersection distance and less than the center distance, the conversion scaling factor is reduced.
(C414) If the current distance is greater than the second intersection distance and greater than the center distance, the conversion scaling factor is reduced.
(C415) If the current distance is greater than the first intersection distance and equal to the center distance, and a current distance between the judgment device and the target device is equal to a current distance between the positioning device and the target device respectively, the conversion scaling factor is reduced.
(C416) If the current distance is equal to the center distance, and the current distance between the judgment device and the target device is unequal to the current distances between the positioning devices and the target device respectively, one effective device is reselected as a judgment device and the other three effective devices are taken as positioning devices to perform continuously.
(C42) When the three spheres have no intersections and are externally separated from each other, and the three spheres are externally separated from a circle or sphere formed by taking the current distance between the judgment device and the target device as a radius respectively, and current distances between the four effective devices and the target device are equal, the conversion scaling factor is enlarged.
selecting one from the two effective devices as a positioning device and the other as a judgment device;
when a device distance between the positioning device and the judgment device is less than an initial distance between the judgment device and the target device, then the corrected value of the conversion scaling factor may be acquired according to a following calculation formula:
the selecting at least one group of N effective devices from known devices that transmit signals to the target device or known devices that receive signals transmitted by the target device may include:
selecting four effective devices having unequal signal intensities located at two opposite sides with two effective devices comprised at each side according to a signal intensity sequence from strong to weak from the known devices that transmit signals to the target device or the known devices that receive signals transmitted by the target device, wherein only coordinate values corresponding to one coordinate axes in position coordinates of the two effective devices located at the same side are unequal.
determining that the target device is within a region range formed by connecting the four effective devices with respect to each group of four effective devices; and
calculating and acquiring a corrected conversion factor of the target device according to a following calculation formula:
determining that the target device is located at the straight line at which the two effective devices are located and a distance sum of the target device to the two effective devices respectively is equal to a distance between the two effective devices with respect to each group of four effective devices; and
calculating and acquiring a corrected conversion factor of the target device according to a following calculation formula:
wherein, L is a device distance between the two effective devices, d_{1} and d_{2} are corrected distances between the two effective devices and the target device respectively, and R_{1} and R_{2} are corresponding signal intensities of the two effective devices respectively.
a device selection module 801 configured to select at least one group of N effective devices from known devices that transmit signals to a target device or known devices that receive signals transmitted by the target device;
a correction module 802 configured to adjust a numerical value of a conversion scaling factor with respect to each group of N effective devices, and seek a corrected value of the conversion scaling factor, the corrected value enabling N circles or spheres formed by taking a position of each effective device as a center and a corrected distance between each effective device and the target device as a radius to have a unique intersection, and
a position acquisition module 803 configured to calculate and acquire a position of the target device by using at least one corrected value of the conversion scaling factor acquired.
enlarge or reduce the numerical value of the conversion scaling factor from an initial value of the conversion scaling factor, and use a current adjusted value of the conversion scaling factor as the corrected value of the conversion scaling factor when the current adjusted value enables the N circles or spheres formed by taking the position of each effective device as the center and the corrected distance between each effective device and the target device as the radius to have the unique intersection.
select any effective device from the N effective devices as a judgment device, and use other N1 effective devices as positioning devices;
start from taking the initial value of the conversion scaling factor as the current adjusted value, judge whether N1 circles or spheres formed by taking a current distance between the N1 effective devices and the target device as a radius to have an intersection and whether a current distance between the judgment device and the target device is equal to an intersection distance between the judgment device and any intersection position, wherein, the current distance is calculated and acquired by using a current value of the conversion scaling factor;
if yes, use the current value of the conversion scaling factor as the corrected value of the conversion scaling factor;
if not, compare the current distance between the judgment device and the target device with a first intersection distance between the judgment device and an intersection position close to the judgment device, a second intersection distance between the judgment device and an intersection position far from the judgment device, and a center distance between the judgment device and a central point of a connecting line of the two intersection positions respectively when the N1 circles or spheres have two intersection positions;
if the current distance is less than the first intersection distance and less than the center distance, or the current distance is less than the second intersection distance and greater than the center distance, enlarge the conversion scaling factor;
if the current distance is greater than the first intersection distance and less than the center distance, or the current distance is greater than the second intersection distance and greater than the center distance, or the current distance is greater than the first intersection distance and equal to the center distance, and a current distance between the judgment device and the target device is equal to current distances between the positioning devices and the target device respectively, reduce the conversion scaling factor;
if the current distance is equal to the center distance, and the current distance between the judgment device and the target device is unequal to the current distances between the positioning devices and the target device respectively, reselect one effective device as a judgment device and use other N1 effective devices as positioning devices to perform continuously; and
when the N1 circles or spheres have no intersections and are externally separated from each other, and the N1 circles or spheres are externally separated from a circle or sphere formed by taking the current distance between the judgment device and the target device as a radius respectively, and current distances between the N effective devices and the target device are equal, enlarge the conversion scaling factor.
If the circle formed by taking the current distance between the judgment device and the target device as the radius is externally separated from any one of the N1 circles, reselect one group of N effective devices to perform continuously; and
if the circle formed by taking the current distance between the judgment device and the target device as the radius is intersected with any circle in the N1 circles, reduce the conversion scaling factor;
if the circle formed by taking the current distance between the judgment device and the target device as the radius is externally separated from all the N1 circles, reselect one group of N effective devices to perform continuously;
when a position coordinate of the N effective devices is a threedimensional coordinate, N is equal to 4; and
when the N1 spheres have no intersection and any two spheres are internally contained, the correction module is further configured to trigger the device selection module to reselect one group of N effective devices.
select one from the two effective devices as a positioning device and the other as a judgment device;
when a device distance between the positioning device and the judgment device is less than an initial distance between the judgment device and the target device, acquire the corrected value of the conversion scaling factor according to a following calculation formula:
wherein, L is a distance between the positioning device and the judgment device, R_{1} is a corresponding signal intensity of the judgment device, and R_{2} is a corresponding signal intensity of the positioning device; C_{cal} is the corrected value of the conversion scaling factor, d_{1} is a corrected distance between the judgment device and the target device, and d_{2} is a corrected distance between the positioning device and the target device;
therefore, the corrected value of the conversion scaling factor is calculated and acquired as follows:
it should be illustrated that a square root of the foregoing formula needs to be a positive value.
select four effective devices having unequal signal intensities located at two opposite sides with two effective devices comprised at each side according to a signal intensity sequence from strong to weak from the known devices that transmit signals to the target device or the known devices that receive signals transmitted by the target device, wherein only coordinate values corresponding to one coordinate axes in position coordinates of the two effective devices located at the same side are unequal, and the effective region range of the known devices for receiving or transmitting signals is a semicircle or semisphere;
the correction module may be specifically configured to:
determine that the target device is within a region range formed by connecting the four effective devices with respect to each group of four effective devices; and
calculate and acquire a corrected conversion factor of the target device according to a following calculation formula:
wherein, a position coordinate of a j^{th} effective device is (X_{j1}, X_{j2}, ..., X_{jm}), M is a dimension of a coordinate space, and M=1, 2, 3...
wherein, j=1, 2, 3 and 4, X_{jm} is an mdimensional coordinate of the j^{th} effective device, and X_{tm} is an mdimensional coordinate of the target device; and d_{j} is a corrected distance between the j^{th} effective device and the target device, wherein, mdimensional coordinates of the four effective devices are unequal.
select two effective devices located at the same straight line according to a signal intensity sequence from strong to weak from the known devices that transmit signals to the target device or the known devices that receive signals transmitted by the target device; and
the correction module is specifically configured to:determine that the target device is located at the straight line at which the two effective devices are located and a distance sum of the target device to the two effective devices respectively is equal to a distance between the two effective devices with respect to each group of two effective devices; and
calculate and acquire a corrected conversion factor of the target device according to a following calculation formula:calculate and acquire a coordinate value of each dimensional coordinate of the target device according to a following calculation formula by using the corrected value of the conversion scaling factor acquired:
wherein, X_{tn} is an ndimensional coordinate of the target device, X_{1n} is an ndimensional coordinate of a first effective device, X_{2n} is an ndimensional coordinate of a second effective device, d_{1} is a corrected distance between the first effective device and the target device, and d_{2} is a corrected distance between the second effective device and the target device; n=1, 2, ..., M, wherein M is a dimension of a coordinate space, and M=1, 2, ..., 3.
selecting at least one group of N effective devices from known devices that transmit signals to a target device or known devices that receive signals transmitted by the target device;
adjusting a numerical value of a conversion scaling factor with respect to each group of N effective devices, and seeking a corrected value of the conversion scaling factor, the corrected value enabling N circles or spheres formed by taking a position of each effective device as a center and a corrected distance between each effective device and the target device as a radius to have a unique intersection; wherein the conversion scaling factor is used to convert a signal intensity of the signal transmitted by the effective device towards the target device or the received signal transmitted by the target device into a distance; and
calculating and acquiring a position of the target device by using at least one corrected value of the conversion scaling factor acquired.
enlarging or reducing the numerical value of the conversion scaling factor from an initial value of the conversion scaling factor, and taking a current adjusted value of the conversion scaling factor as the corrected value of the conversion scaling factor when the current adjusted value enables the N circles or spheres formed by taking the position of each effective device as the center and the corrected distance between each effective device and the target device as the radius to have the unique intersection.
selecting any effective device from the N effective devices as a judgment device, and taking other N1 effective devices as positioning devices;
starting from taking the initial value of the conversion scaling factor as the current adjusted value, judging whether N1 circles or spheres formed by taking a current distance between the N1 effective devices and the target device as a radius to have an intersection and whether a current distance between the judgment device and the target device is equal to an intersection distance between the judgment device and any intersection position; wherein, the current distance is calculated by using a current value of the conversion scaling factor;
if yes, taking the current value of the conversion scaling factor as the corrected value of the conversion scaling factor;
if not, comparing the current distance between the judgment device and the target device with a first intersection distance between the judgment device and an intersection position close to the judgment device, a second intersection distance between the judgment device and an intersection position far from the judgment device, and a center distance between the judgment device and a central point of a connecting line of the two intersection positions respectively when the N1 circles or spheres have two intersection positions;
if the current distance is less than the first intersection distance and less than the center distance, or the current distance is less than the second intersection distance and greater than the center distance, enlarging the conversion scaling factor;
if the current distance is greater than the first intersection distance and less than the center distance, or the current distance is greater than the second intersection distance and greater than the center distance; or the current distance is greater than the first intersection distance and equal to the center distance, and a current distance between the judgment device and the target device is equal to current distances between the positioning devices and the target device respectively, reducing the conversion scaling factor;
if the current distance is equal to the center distance, and the current distance between the judgment device and the target device is unequal to the current distances between the positioning devices and the target device respectively, reselecting one effective device as a judgment device and taking other N1 effective devices as positioning devices to perform continuously; and
when the N1 circles or spheres have no intersections and are externally separated from each other, and the N1 circles or spheres are externally separated from a circle or sphere formed by taking the current distance between the judgment device and the target device as a radius respectively, and current distances between the N effective devices and the target device are equal, enlarging the conversion scaling factor.
if the circle formed by taking the current distance between the judgment device and the target device as the radius comprises any circle in the N1 circles, reselecting one group of N effective devices to perform continuously; and
if the circle formed by taking the current distance between the judgment device and the target device as the radius is intersected with any circle in the N1 circles, reducing the conversion scaling factor;
when the N1 circles have one intersection position and are internally tangent, the method further comprises:
if the circle formed by taking the current distance between the judgment device and the target device as the radius is externally separated from all the N1 circles, reselecting one group of N effective devices to perform continuously;
when a position coordinate of the N effective devices is a threedimensional coordinate, N is equal to 4; and
when the N1 spheres have no intersection and any two spheres are internally contained, the method further comprises:reselecting one group of N effective devices to perform continuously.
selecting one from the two effective devices as a positioning device and the other as a judgment device;
when a device distance between the positioning device and the judgment device is less than an initial distance between the judgment device and the target device, acquiring the corrected value of the conversion scaling factor according to a following calculation formula:
selecting four effective devices having unequal signal intensities located at two opposite sides with two effective devices comprised at each side according to a signal intensity sequence from strong to weak from the known devices that transmit signals to the target device or the known devices that receive signals transmitted by the target device, wherein only coordinate values corresponding to one coordinate axes in position coordinates of the two effective devices located at the same side are unequal, and the effective region range of the known devices for receiving or transmitting signals is a semicircle or semisphere;
the adjusting the numerical value of the conversion scaling factor with respect to each group of four effective devices, and seeking the corrected value of the conversion scaling factor, comprises:
determining that the target device is within a region range formed by connecting the four effective devices with respect to each group of four effective devices; and
calculating and acquiring a corrected conversion factor of the target device according to a following calculation formula:
wherein, j=1, 2, 3 and 4, X_{jm} is an mdimensional coordinate of a j^{th} effective device, and X_{tm} is an mdimensional coordinate of the target device; and d_{j} is a corrected distance between the j^{th} effective device and the target device, wherein, mdimensional coordinates of the four effective devices are unequal.
selecting two effective devices located at the same straight line according to a signal intensity sequence from strong to weak from the known devices that transmit signals to the target device or the known devices that receive signals transmitted by the target device; and
the adjusting the numerical value of a conversion scaling factor with respect to each group of four effective devices, and seeking the corrected value of the conversion scaling factor, comprises:
determining that the target device is located at the straight line at which the two effective devices are located and a distance sum of the target device to the two effective devices respectively is equal to a distance between the two effective devices with respect to each group of four effective devices; and
calculating and acquiring a corrected conversion factor of the target device according to a following calculation formula:
wherein, L is a device distance between the two effective devices, d_{1} and d_{2} are corrected distances between the two effective devices and the target device respectively, and R_{1} and R_{2} are corresponding signal intensities of the two effective devices respectively.
calculating and acquiring a coordinate value of each dimensional coordinate of the target device according to a following calculation formula by using the corrected value of the conversion scaling factor acquired:
wherein, X_{m} is an ndimensional coordinate of the target device, X_{1n} is an ndimensional coordinate of a first effective device, X_{2n} is an ndimensional coordinate of a second effective device, d_{1} is a corrected distance between the first effective device and the target device, and d_{2} is a corrected distance between the second effective device and the target device; and
using a mean coordinate value of the coordinate value of each dimensional coordinate of the target device calculated and acquired by using each corrected value to constitute a position coordinate of the position of the target device.
a device selection module configured to select at least one group of N effective devices from known devices that transmit signals to a target device or known devices that receive signals transmitted by the target device;
a correction module configured to adjust a numerical value of a conversion scaling factor with respect to each group of N effective devices, and seek a corrected value of the conversion scaling factor, the corrected value enabling N circles or spheres formed by taking a position of each effective device as a center and a corrected distance between each effective device and the target device as a radius to have a unique intersection, wherein, the conversion scaling factor is used to convert a signal intensity of the signal transmitted by the effective device towards the target device or the received signal transmitted by the target device into a distance; and
a position acquisition module configured to calculate and acquire a position of the target device by using at least one corrected value of the conversion scaling factor acquired.
enlarge or reduce the numerical value of the conversion scaling factor from an initial value of the conversion scaling factor, and take a current adjusted value of the conversion scaling factor as the corrected value of the conversion scaling factor when the current adjusted value enables the N circles or spheres formed by taking the position of each effective device as the center and the corrected distance between each effective device and the target device as the radius to have the unique intersection.
select any effective device from the N effective devices as a judgment device, and take other N1 effective devices as positioning devices;
start from taking the initial value of the conversion scaling factor as the current adjusted value, judge whether N1 circles or spheres formed by taking a current distance between the N1 effective devices and the target device as a radius to have an intersection and whether a current distance between the judgment device and the target device is equal to an intersection distance between the judgment device and any intersection position, wherein the current distance is calculated and acquired by using a current value of the conversion scaling factor;
if yes, take the current value of the conversion scaling factor as the corrected value of the conversion scaling factor;
if not, compare the current distance between the judgment device and the target device with a first intersection distance between the judgment device and an intersection position close to the judgment device, a second intersection distance between the judgment device and an intersection position far from the judgment device, and a center distance between the judgment device and a central point of a connecting line of the two intersection positions respectively when the N1 circles or spheres have two intersection positions;
if the current distance is less than the first intersection distance and less than the center distance, or the current distance is less than the second intersection distance and greater than the center distance, enlarge the conversion scaling factor;
if the current distance is greater than the first intersection distance and less than the center distance, or the current distance is greater than the second intersection distance and greater than the center distance, or the current distance is greater than the first intersection distance and equal to the center distance, and a current distance between the judgment device and the target device is equal to current distances between the positioning devices and the target device respectively, reduce the conversion scaling factor;
if the current distance is equal to the center distance, and the current distance between the judgment device and the target device is unequal to the current distances between the positioning devices and the target device respectively, reselect one effective device as a judgment device and take other N1 effective devices as positioning devices to perform continuously; and
when the N1 circles or spheres have no intersections and are externally separated from each other, and the N1 circles or spheres are externally separated from a circle or sphere formed by taking the current distance between the judgment device and the target device as a radius respectively, and current distances between the N effective devices and the target device are equal, enlarge the conversion scaling factor.
if the circle formed by taking the current distance between the judgment device and the target device as the radius is externally separated from all the N1 circles, reselect one group of N effective devices to perform continuously; and
if the circle formed by taking the current distance between the judgment device and the target device as the radius is intersected with any circle in the N1 circles, reduce the conversion scaling factor;
when the N1 circles have one intersection position and are internally tangent, the correction module is further configured to:
if the circle formed by taking the current distance between the judgment device and the target device as the radius is externally separated from all the N1 circles, reselect one group of N effective devices to perform continuously;
when a position coordinate of the N effective devices is a threedimensional coordinate, N is equal to 4; and
when the N1 spheres have no intersection and any two spheres are internally contained, the correction module is further configured to trigger the device selection module to reselect one group of N effective devices.
select one from the two effective devices as a positioning device and the other as a judgment device;
when a device distance between the positioning device and the judgment device is less than an initial distance between the judgment device and the target device, acquire the corrected value of the conversion scaling factor according to a following calculation formula:
select four effective devices having unequal signal intensities located at two opposite sides with two effective devices comprised at each side according to a signal intensity sequence from strong to weak from the known devices that transmit signals to the target device or the known devices that receive signals transmitted by the target device, wherein only coordinate values corresponding to one coordinate axes in position coordinates of the two effective devices located at the same side are unequal, and the effective region range of the known devices for receiving or transmitting signals is a semicircle or semisphere;
the correction module is specifically configured to:
determine that the target device is within a region range formed by connecting the four effective devices with respect to each group of four effective devices; and
calculate and acquire a corrected conversion factor of the target device according to a following calculation formula:
wherein, j=1, 2, 3 and 4, X_{jm} is an mdimensional coordinate of a j^{th} effective device, and X_{tm} is an mdimensional coordinate of the target device; and d_{j} is a corrected distance between the j^{th} effective device and the target device, wherein, mdimensional coordinates of the four effective devices are unequal.
select two effective devices located at the same straight line according to a signal intensity sequence from strong to weak from the known devices that transmit signals to the target device or the known devices that receive signals transmitted by the target device; and
the correction module is specifically configured to:determine that the target device is located at the straight line at which the two effective devices are located and a distance sum of the target device to the two effective devices respectively is equal to a distance between the two effective devices with respect to each group of four effective devices; and
calculate and acquire a corrected conversion factor of the target device according to a following calculation formula: