A kind of localization method under indoor nlos environment based on UWB rangingsTechnical field
The present invention relates to the service technology field of position, under specially a kind of indoor nlos environment based on UWB rangingsLocalization method.
Background technology
As the interior space of people's activity is more and more huger and complexity, the demand of indoor location-based positioning service is got overCome more obvious.Such as, in large-scale shopping square, people can be quickly found out required commodity；In hospital, administrative staff canMedical Devices and patient to hospital carry out in real time accurately positioning；In rescue sites such as fire, commanding is to indoor fire-fightingDetermination of member position etc..It is well known that GPS (GLONASS) satellite-signals can cause in serious shielding part orWhole positioning functions are lost, and are highly susceptible to the interference of multi-path environment, therefore using GPS are difficult indoors reality under environmentNow position.Under the huge demand driving in market, the indoor locating system (Indoor being consistent with indoor environment is urgently builtPosition System, IPS) become numerous scientific worker's focus of attention.
UWB technology is an important development direction of wireless communication field, it has also become the content of domestic and international hot research itOne.When UWB applies to short distance indoor positioning, its high positioning precision, strong penetration capacity, anti-multipath, low transmitting work(Rate, the clear superiority as it with other indoor positioning technologies.However, compared with broad outdoor environment, indoor wireless communicationRoad environment wants many of complexity, and signal meeting in communication process, by the stop or reflection of the barriers such as wall, furniture, ground, is drawnPlay non line of sight (Non-Line-of-Sight, NLOS) phenomenon.In this case, in way is propagated excess delay can occur for signal,So that ranging carries positivity bias so that positioning precision has a strong impact on, so the high accuracy positioning under nlos environment indoorsAs urgent need to solve the problem.Therefore, we have proposed the localization method under a kind of indoor nlos environment based on UWB rangingsCome into operation, to solve the above problems.
The content of the invention
It is an object of the invention to provide the localization method under a kind of indoor nlos environment based on UWB rangings, to solveThe problem of being proposed in certainly above-mentioned background technology.
To achieve the above object, the present invention provides following technical scheme：A kind of indoor nlos environment based on UWB rangingsUnder localization method, should comprising the following steps that based on the localization method under the indoor nlos environment of UWB rangings：
S1：Each beaconing nodes are laid, and set up indoor relative position coordinates system, the coordinate of each beaconing nodes is measured and recordValue；Each beacon coordinate is inputted into server, and server is connected with beaconing nodes by LAN；
S2：The positioning instruction that server is assigned in each beaconing nodes response of step S1, launches pulse signal, searches mesh to be measuredMark；
S3：The pulse signal that intended recipient to be measured is sent into step S2 by each beaconing nodes, reflects the signal and returns immediatelySending node；
S4：Each beaconing nodes receive the pulse signal reflected in step S3 by target to be measured, using with launching arteries and veinsIdentical template signal is rushed, and then carries out correlation demodulation, signal time delay estimation is carried out and obtains between beaconing nodes and target to be measuredDistance measuring, and carry out channel statistical feature extraction；
S5：Each beaconing nodes utilize step S1 LAN, by the distance measuring obtained in step S4, pulse signal channelThe data such as statistical nature are sent to server；
S6：The pusing channel statistical nature that each beaconing nodes in server receiving step S5 are sent, carries out non line of sight knowledgeNot, on the basis of identification, using the distance measuring and the position coordinates of each beacon of each beacon, by location algorithm, estimate and treatSurvey position coordinates of the target in relative position coordinates system；
S7：The estimated location obtained in step S6 is included on terminal display, so as to realize indoor nlos environmentUnder target positioning.
It is preferred that, in the step S1, the beaconing nodes include UWB detectors and wireless communication module, the UWBDetector is used to modulate, launch, receive, demodulate pulse signal, and extracts signaling channel statistical nature；The LAN is by roadSet up by device, be the wireless communication protocol that beaconing nodes can be supported；The target to be measured includes an active radio frequency label, canSo that the pulse signal received is amplified into reflection；The server is used to initiate target positioning instruction, is issued to each letterMark node and carry out target acquisition.
It is preferred that, in the step S4, signaling channel statistical nature, which is extracted, is specially：Beaconing nodes receive reflected signalR (t), extracts and receives signal gross energy εr, average additional time delay τmed, root mean square delay, τrms, kurtosis k, the channel statistical such as degree of bias sThe calculation formula of feature, wherein each feature is respectively：
Wherein
Wherein
It is preferred that, in the step S6, on the server, support vector cassification is passed through using signaling channel statistical natureWhether device, identification sorting pulse signal is non line of sight transmission, and the signal for being identified as line-of-sight transmission is used for into location estimation, and will be knownNot Wei non line of sight transmission beacon abandon be not involved in location estimation process.
Compared with prior art, the beneficial effects of the invention are as follows：The present invention is special by extracting UWB signal propagation channel statisticsLevy, non line of sight signal identification is realized using conventional support vector machine classifier, so as to eliminate non line of sight signal in positioning stageThe range error brought, seriously blocks being accurately positioned with very big advantage under complex environment indoors.
Brief description of the drawings
Fig. 1 is space layout figure of the present invention；
Fig. 2 is present system Organization Chart；
Fig. 3 is non line of sight identification process figure of the present invention.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, completeSite preparation is described, it is clear that described embodiment is only a part of embodiment of the invention, rather than whole embodiments.It is based onEmbodiment in the present invention, it is every other that those of ordinary skill in the art are obtained under the premise of creative work is not madeEmbodiment, belongs to the scope of protection of the invention.
The present invention provides a kind of technical scheme：A kind of localization method under indoor nlos environment based on UWB rangings, shouldLocalization method under indoor nlos environment based on UWB rangings is comprised the following steps that：
S1：As shown in figure 1, laying each beaconing nodes (including 5 beacons in the alignment system shown in Fig. 1), and set upIndoor relative position coordinates system, measures and records the coordinate value of each beaconing nodes；Each beacon coordinate is inputted into server, and will clothesBusiness device is connected with beaconing nodes by LAN；The beaconing nodes include UWB detectors and wireless communication module, the UWBDetector is used to modulate, launch, receive, demodulate pulse signal, and extracts signaling channel statistical nature；The LAN is by roadSet up by device, be the wireless communication protocol that beaconing nodes can be supported；The target to be measured includes an active radio frequency label, canSo that the pulse signal received is amplified into reflection；The server is used to initiate target positioning instruction, is issued to each letterMark node and carry out target acquisition；
S2：The positioning instruction that server is assigned in each beaconing nodes response of step S1, launches pulse signal, searches mesh to be measuredMark；
As shown in Fig. 2 beaconing nodes include impulse generator, transmitting antenna, reception antenna, demodulation correlator and channel spyLevy extraction computing module.After beaconing nodes receive the positioning instruction that server is assigned, via impulse generator, by baseband signalIt is modulated on carrier wave, is sent by transmitting antenna；
S3：The pulse signal that intended recipient to be measured is sent into step S2 by each beaconing nodes, reflects the signal and returns immediatelySending node；
As shown in Fig. 2 target to be measured carries an active radio frequency label, the pulse signal received can be putGreatly, and reflect away；
S4：Each beaconing nodes receive the pulse signal reflected in step S3 by target to be measured, using with launching arteries and veinsIdentical template signal is rushed, and then carries out correlation demodulation, signal time delay estimation is carried out and obtains between beaconing nodes and target to be measuredDistance measuring, and carry out channel statistical feature extraction；
As shown in figure 3, beaconing nodes receive the radiofrequency signal reflected via target to be measured, correlation demodulation is carried out, is obtainedSignal time delay, if beacon A is in t0Moment is reflected after sending a signal to target to be measured, intended recipient to be measured, in t1Moment A is receivedTo backhaul signals, because intended recipient to launch time is t ', c is propagation velocity of electromagnetic wave, then the distance between beacon A and targetForBeaconing nodes receive backhaul signals r (t), extract and receive signal gross energy εr, average additional hoursProlong τmed, root mean square delay, τrms, kurtosis k, the channel statistical feature such as degree of bias s, the calculation formula of wherein each feature is respectively：
Wherein
Wherein
S5：Each beaconing nodes utilize step S1 LAN, by the distance measuring obtained in step S4, pulse signal channelThe data such as statistical nature are sent to server；
S6：The pusing channel statistical nature that each beaconing nodes in server receiving step S5 are sent, carries out non line of sight knowledgeNot, on the basis of identification, using the distance measuring and the position coordinates of each beacon of each beacon, by location algorithm, estimate and treatSurvey position coordinates of the target in relative position coordinates system；
As shown in figure 3, the channel statistical feature of extraction is denoted as into vector f=[εr,τmed,τrms, k, s], each is obtainedThe characteristic vector arrived, is put into the support vector machine classifier trained, signal identification label l ∈ { -1 ,+1 } is obtained, during l=-1It is non line of sight signal during l=+1 for line-of-sight signal.The distance measuring only obtained in positioning stage using line-of-sight signal, using biographyThree side location algorithms of uniting can be obtained by the location estimation of target；
S7：The estimated location obtained in step S6 is included on terminal display, so as to realize indoor nlos environmentUnder target positioning.
Although an embodiment of the present invention has been shown and described, for the ordinary skill in the art, can be withA variety of changes, modification can be carried out to these embodiments, replace without departing from the principles and spirit of the present invention by understandingAnd modification, the scope of the present invention is defined by the appended.