CN102802225A - Indoor/outdoor seamless positioning and switching method based on Euclidean distance judgment - Google Patents

Abstract

The invention discloses an indoor/outdoor seamless positioning and switching method based on Euclidean distance judgment, relating to an indoor/outdoor seamless positioning and switching method and aiming to meet requirements for indoor/outdoor seamless positioning and switching. According to the invention, the traditional Euclidean distance calculation process in a fingerprint positioning technology is used to judge whether a user is in an indoor positioned service area by means of calculating an absolute value of the Euclidean distance between RSS (Root-Sum Square) components of sampling points and reference points, and accordingly, a user machine is controlled to be switched between an indoor positioning service and an outdoor positioning service. The indoor/outdoor seamless positioning and switching method disclosed by the invention is suitable for inner/outer seamless switching of the wireless positioning technology.

Description

The seamless location of indoor and outdoor changing method based on the Euclidean distance judgement

Technical field

The present invention relates to the seamless location of a kind of indoor and outdoor changing method.

Background technology

Present radio position finding radio directional bearing technology is mainly according to different two kinds of indoor positioning and the outdoor location that are divided into of applied environment.Outdoor positioning service mainly is to be provided by GPS (GNSS), and is quite ripe at present.And at the indoor positioning technical elements, through years development, also near ripe.Relatively the research direction of main flow is under the system of all kinds of wireless networks at present, like WLAN, bluetooth or ZigBee etc., based on the fingerprint location technology that receives signal strength signal intensity (RSS).

In the process that realizes indoor fingerprint location technology, at first to set up indoor RSS fingerprint image, promptly at the vectorial S of the measure R SS of the reference point place of some location awares value _(i):

S _(i)=(a _i1,a _i2,a _i3,…,a _ij,…a _iM)

A in the formula _IjRepresent the signal strength values that i reference point place observes j indoor signal node obtain, M is an indoor signal node number.The RSS vector of all reference points can write down and be recorded as a database C, i.e. fingerprint image, and N is the reference point number in the formula:

$C=\left[\begin{array}{c}{S}_{\left(1\right)}\\ S_{\left(2\right)}\\ S_{\left(3\right)}\\ .\\ .\\ .\\ S_{\left(N\right)}\end{array}\right]$

In position fixing process, the RSS vector that subscriber computer receives in real time can be represented by S '

S'=(a ₁,a ₂,a ₃,…,a _j,…a _M)

Each RSS vector in this fingerprint image is compared with the RSS vector S ' that measures, assert that the Euclidean distance reckling is current user position.The computational process of Euclidean distance is shown below:

$D(S^{\′},S_{\left(i\right)})=\sqrt{\underset{j=1}{\overset{M}{\mathrm{\Σ}}}{(a_j-a_{\mathrm{ij}})}^2}$

Owing to only focus on the application under the indoor environment, the indoor positioning technology is only set up fingerprint image in the interior space.

Simultaneously owing to need not consider the problem that the user is switched between indoor and outdoor surroundings; In the indoor positioning technology, be defaulted as in the service area that the user must be in indoor positioning; The system of institute has nothing to do with the absolute value situation of annotating Euclidean distance, just seeks out minimum value, and is used.

And in the practical application in future; The service (LBS) of user's inevitable requirement position-based information can not interrupted along with the variation of position; This just requires can level and smooth switching under two kinds of environment of indoor and outdoor to user's positioning service, to guarantee the seamless covering of positioning service.

Because it is practical that the indoor positioning technology drops into fully, positioning service is not covered indoor as yet, so the switching problem that present research is not concerned about between indoor, outdoor two kinds of environment.But can predict, after the indoor positioning technology maturation, switching problem will become inevitable problem in the process that realizes seamless positioning service.

Summary of the invention

The present invention is the demand of the seamless location of indoor and outdoor being switched in order to adapt to, thereby a kind of seamless location of indoor and outdoor changing method based on the Euclidean distance judgement is provided.

Based on the seamless location of the indoor and outdoor changing method of Euclidean distance judgement,

It is based on the switched system realization of the seamless location of indoor and outdoor, and said system comprises receiver and N radio access node; A said N radio access node is distributed in indoor, and receiver receives the observation vector from N radio access node RSS value; N is a positive integer;

The seamless location of indoor and outdoor changing method based on the Euclidean distance judgement is realized by following steps:

Step 1, judges whether under outdoor environment, if judged result for not, then execution in step two; If judged result is for being that then execution in step three;

Step 2, the user is carried out the WLAN positioning service, and execution in step 21;

Step 2 one, according to the WLAN positioning result, whether judges is in the preset near scope of " going out " switch area, if judged result is then returned execution in step two for not; If judged result is for being that then execution in step two or two;

Step 2 two, startup GNSS signal detect the user, and calculate the Euclidean distance of user and " going out " switch area, and execution in step two or three;

Whether step 2 three, determining step two or two detected Euclidean distances are greater than a preset thresholding; If judged result is for being that then execution in step two or four; If judged result is that then execution in step three;

Step 2 four, the user is kept WLAN service, and the user kept return execution in step two or two under the state of WLAN service;

Step 3, the user is carried out the GNSS positioning service, and execution in step 31;

Step 3 one, according to the GNSS positioning result, whether judges is in the preset near scope of " going out " switch area, if judged result is then returned execution in step three for not; If judged result is for being that then execution in step three or two;

The fingerprint image of step 3 two, basis " entering " switch area carries out the WLAN signal search to the user;

Step 3 three, according to the WLAN signal search in the step 3 two as a result judges whether be in the preset range of " entering " switch area, if judged result is then returned execution in step three or two for not under the state that the user is kept the GNSS service; If judged result is that then execution in step three or four;

The Euclidean distance of step 3 four, calculating user and " entering " switch area, and whether judge said Euclidean distance greater than No. two preset thresholdings, if judged result is that then execution in step two; If judged result is for being that then execution in step three or five;

Step 3 five, the user is kept the GNSS positioning service, and the user kept return execution in step three or four under the state of GNSS service.

" enter " switch area and " going out " switch area adopts the mode of RSS fingerprint image to set.

The present invention can realize the seamless location of indoor and outdoor is switched, and can satisfy the demand that Modern wireless communication is switched the seamless location of indoor and outdoor.

Description of drawings

Fig. 1 is the sketch map that concerns between switch area of the present invention and indoor, the outdoor two kinds of positioning services; Fig. 2 is a schematic flow sheet of the present invention; Fig. 3 is the emulation sketch map in the embodiment one.

Embodiment

Embodiment one, combination Fig. 1 and Fig. 2 explain this embodiment, based on the seamless location of the indoor and outdoor changing method of Euclidean distance judgement,

It is based on the switched system realization of the seamless location of indoor and outdoor, and said system comprises receiver and N radio access node; A said N radio access node is distributed in indoor, and receiver receives the observation vector from N radio access node RSS value; N is a positive integer;

The seamless location of indoor and outdoor changing method based on the Euclidean distance judgement is realized by following steps:

Step 1, judges whether under outdoor environment, if judged result for not, then execution in step two; If judged result is for being that then execution in step three;

Step 2, the user is carried out the WLAN positioning service, and execution in step 21;

Step 2 one, according to the WLAN positioning result, whether judges is in the preset near scope of " going out " switch area, if judged result is then returned execution in step two for not; If judged result is for being that then execution in step two or two;

Step 2 two, startup GNSS signal detect the user, and calculate the Euclidean distance of user and " going out " switch area, and execution in step two or three;

Whether step 2 three, determining step two or two detected Euclidean distances are greater than a preset thresholding; If judged result is for being that then execution in step two or four; If judged result is that then execution in step three;

Step 2 four, the user is kept WLAN service, and the user kept return execution in step two or two under the state of WLAN service;

Step 3, the user is carried out the GNSS positioning service, and execution in step 31;

Step 3 one, according to the GNSS positioning result, whether judges is in the preset near scope of " going out " switch area, if judged result is then returned execution in step three for not; If judged result is for being that then execution in step three or two;

The fingerprint image of step 3 two, basis " entering " switch area carries out the WLAN signal search to the user;

Step 3 three, according to the WLAN signal search in the step 3 two as a result judges whether be in the preset range of " entering " switch area, if judged result is then returned execution in step three or two for not under the state that the user is kept the GNSS service; If judged result is that then execution in step three or four;

The Euclidean distance of step 3 four, calculating user and " entering " switch area, and whether judge said Euclidean distance greater than No. two preset thresholdings, if judged result is that then execution in step two; If judged result is for being that then execution in step three or five;

Step 3 five, the user is kept the GNSS positioning service, and the user kept return execution in step three or four under the state of GNSS service.

" enter " switch area and " going out " switch area adopts the mode of RSS fingerprint image to set.

Realize based on the WLAN system indoor fingerprint of the present invention location.At first need, receiver judge self-position when starting shooting, to confirm next step switching kind through information such as the visible star of GNSS, WLAN signal strength signal intensities.When inferring through information such as customer location, speed; Realize when the user needs handed over service, be divided into two kinds of situation and carry out: in " entering " process, need at first to receive the necessary informations such as RSS fingerprint image of switch area through wlan network; When the Euclidean distance between RSS vector and fingerprint image during greater than thresholding; Keep outdoor positioning service, and, adopt the result of indoor positioning service when this Euclidean distance during less than thresholding.In " going out " process, the fingerprint image of switch area has been positioned to accomplish when indoor the user to be downloaded, and only need when the user gets into the switch area, judge whether to switch through Euclidean distance.

One: set up crossover region

For realizing the seamless switching of indoor and outdoor positioning service, must there be certain crossover region in indoor node signal and outdoor GNSS signal, and promptly in certain period, receiver can obtain the service that two navigation systems provide simultaneously.Because RSS fingerprint locating accuracy reached in the 2m at present, far above the position error of the 10m magnitude of free-standing GPS, so in the present invention, the user uses the priority of indoor fingerprint navigation system greater than outdoor GNSS system.

For realizing setting up the crossover region of indoor and outdoor positioning service, need in closing on the exterior space of building, also set up same fingerprint image, make the user can under the part outdoor environment, obtain the service that provides by indoor locating system.This part fingerprint image The corresponding area is the switch area among the present invention.

The process of setting up the RSS fingerprint image is following, promptly at the vectorial S of the measure R SS of the reference point place of some location awares value _(i)

S _(i)=(a _i1,a _i2,a _i3,…,a _ij,…a _iM)

A in the formula _IjRepresent the signal strength values that i reference point place observes j indoor signal node obtain, M is an indoor signal node number.The RSS vector of all reference points can write down and be recorded as a database C, i.e. fingerprint image, and N is the reference point number in the formula.

$C=\left[\begin{array}{c}{S}_{\left(1\right)}\\ S_{\left(2\right)}\\ S_{\left(3\right)}\\ .\\ .\\ .\\ S_{\left(N\right)}\end{array}\right]$

Whether receiver can need carry out handover operation through known information judges such as indoor node signal strength signal intensity, customer location and speed whether near the switch area in the present invention.

Two: compute euclidian distances

In position fixing process, the RSS vector that subscriber computer receives in real time can be represented by S '

S'=(a ₁,a ₂,a ₃,…,a _j,…a _M)

Each RSS vector in this fingerprint image is compared with the RSS vector S ' that measures, assert that the Euclidean distance reckling is current user position.The computational process of Euclidean distance is shown below:

$D(S^{\′},S_{\left(i\right)})=\sqrt{\underset{j=1}{\overset{M}{\mathrm{\Σ}}}{(a_j-a_{\mathrm{ij}})}^2}$

In handoff procedure; Receiver is monitored the RSS value of peripheral indoor positioning node all the time; If when the minimum Eustachian distance of RSS vector is worth greater than certain in detected RSS vector and the fingerprint image, assert that then this RSS vector is not present in the fingerprint image, the user is in beyond the service area of interior location.

When preventing that the user is in the edge, switch area, " shake " problem that receiver switches under two kinds of station-keeping modes back and forth appears, " enter " among the present invention with " going out " process employed Zone switched can be different.When the user when indoor environment is moved towards outdoor environment, in the process of promptly " going out ", receiver is with reference to bigger switch area.Switch to indoor environment and work as the user from outdoor environment, receiver is with reference to a less switch area in the process of promptly " entering ".

Below, test effect of the present invention through emulation experiment:

Fig. 3 is the software emulation experiment about Euclidean distance.Simulated the indoor environment of a spaciousness and the outdoor environment of periphery thereof in the experiment, 4 AP of indoor even layout, the transmitting power of each AP is-17dBm.Use the decline of classical logarithmic model simulation WLAN signal in the emulation, use floor decay factor model to simulate the decay of WLAN signal after through walls.The foundation of RSS fingerprint image is extended 10 meters outside wall, exist as crossover region.

White box is represented room wall among Fig. 3, and white circle is represented the AP position, and saturate part representes that detected RSS vector is more little with the Euclidean distance of fingerprint image, and white dashed line is represented the switch area among the figure.As can be seen from the figure; The minimum Eustachian distance of test point in Zone switched and the vector of the RSS between reference point generally is lower than 2 units; And beyond the switch area test point minimum Eustachian distance far away mostly at 3 more than the unit, some in addition up to 10 more than the unit.

Can find out,, can effectively distinguish the user whether in the service area of indoor positioning through the observation of minimum Eustachian distance.

Fig. 1 has provided the relation between switch area and two kinds of positioning service districts of indoor and outdoor.Wherein: mark 21 is indoor positioning nodes; Mark 22 is indoor positioning service areas; Mark 23 is " going out " switch areas; Mark 24 is " entering " switch areas; Mark 25 is doors; Mark 26 is users.

The present invention utilizes the process of existing compute euclidian distances in the fingerprint location technology; Absolute value through the Euclidean distance of RSS vector between calculating sampling point and reference point; Come judges whether to be in the service area of indoor positioning, and control subscriber computer with this and between the indoor and outdoor positioning service, switch.

Claims (2)

1. based on the seamless location of the indoor and outdoor changing method of Euclidean distance judgement, it is characterized in that:

It is based on the switched system realization of the seamless location of indoor and outdoor, and said system comprises receiver and N radio access node; A said N radio access node is distributed in indoor, and receiver receives the observation vector from N radio access node RSS value; N is a positive integer;

The seamless location of indoor and outdoor changing method based on the Euclidean distance judgement is realized by following steps:

Step 1, judges whether under outdoor environment, if judged result for not, then execution in step two; If judged result is for being that then execution in step three;

Step 2, the user is carried out the WLAN positioning service, and execution in step 21;

Step 2 one, according to the WLAN positioning result, whether judges is in the preset near scope of " going out " switch area, if judged result is then returned execution in step two for not; If judged result is for being that then execution in step two or two;

Step 2 two, startup GNSS signal detect the user, and calculate the Euclidean distance of user and " going out " switch area, and execution in step two or three;

Whether step 2 three, determining step two or two detected Euclidean distances are greater than a preset thresholding; If judged result is for being that then execution in step two or four; If judged result is that then execution in step three;

Step 2 four, the user is kept WLAN service, and the user kept return execution in step two or two under the state of WLAN service;

Step 3, the user is carried out the GNSS positioning service, and execution in step 31;

Step 3 one, according to the GNSS positioning result, whether judges is in the preset near scope of " going out " switch area, if judged result is then returned execution in step three for not; If judged result is for being that then execution in step three or two;

The fingerprint image of step 3 two, basis " entering " switch area carries out the WLAN signal search to the user;

Step 3 three, according to the WLAN signal search in the step 3 two as a result judges whether be in the preset range of " entering " switch area, if judged result is then returned execution in step three or two for not under the state that the user is kept the GNSS service; If judged result is that then execution in step three or four;

The Euclidean distance of step 3 four, calculating user and " entering " switch area, and whether judge said Euclidean distance greater than No. two preset thresholdings, if judged result is that then execution in step two; If judged result is for being that then execution in step three or five;

Step 3 five, the user is kept the GNSS positioning service, and the user kept return execution in step three or four under the state of GNSS service.

2. the seamless location of the indoor and outdoor changing method based on the Euclidean distance judgement according to claim 1 is characterized in that the mode of " entering " switch area and " going out " switch area employing RSS fingerprint image is set.

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