1, radio frequency identifies technology of indoor fixed position

 

 

Radio frequency identifies technology of indoor fixed position to use radio frequency means, fixed antenna moves wireless and telegraphic date into electromagnetism field, adherent after the label at article passes magnetic field, generate faradic convey data go out, identify the end that locates with trigonometry in order to achieve with exchanging data to two-way communication more.

 

Radio frequency identifying is indoor distance of action of fixed position technology is very close, but the information that it can get precision of centimeter of class fixed position inside a few millisecond, and because electromagnetism field is not the advantage such as apparent distance, transmission range is very big, and the volume of the label is minorrer, cost is lower. But its do not have communication capacity, interference rejection ability is poorer, inconvenience arrives at conformity in other system, and the safe privacy safeguard of the user and international standardization are not quite perfect.

 

Radio frequency identifies indoor fixed position to had been used extensively to be in by storehouse, factory, bazaar goods, commodity is on the move on fixed position.

 

2, technology of Wi-Fi indoor fixed position

 

Wi-Fi locates the technology has two kinds, one kind is the wireless signal strength that receives a point through mobile equipment and 3 wireless networks, divide algorithm through difference, will compare essence of life to be opposite definitely of person and car undertake trigonometry locates. Another kind is the signal intensity that the firm position that records huge amount beforehand nods, through using new the database that the signal intensity contrast of affiliation equipment has huge amount data, will determine the position.

 

Wi-Fi fixed position is applying the implementation inside the domain extensively complex big range fixed position, monitor and track the task, total precision is taller, but the precision that is used at indoor fixed position can achieve 2 meters or so only, cannot accomplish essence of life to follow fixed position. As a result of Wi-Fi road by implement with mobile terminal gain ground, make location system OK share a network with other client, hardware cost is very low, and the location system of Wi-Fi can reduce radio frequency (RF) disturbs possibility.

 

Wi-Fi fixed position applies to pair of people or the fixed position navigation of the car, can wait for all sorts of situations that need fixed position navigation at park of medical establishment, theme, factory, bazaar.

 

3, exceed a broadband (technology of UWB) fixed position

 

Exceeding broadband technology is in recent years burgeoning brand-new, as wireless as the communication that traditional communication technology has great difference new technology. It does not need to use the carrier wave in traditional communication system, have accept second through send and be being received however or under small second class extremely narrow pulse will transmit data, have 3.1~10.6GHz to measure the bandwidth of class thereby. Current, include the United States, japan, the country that waits inside is studying Canada this technology, good prospect is had in domain of wireless and indoor fixed position.

 

UWB technology is a kind of transmission rate tall, emissive power is inferior, penetrable capability is stronger and it is to be based on extremely narrow the wireless technology of pulse, without carrier wave. Be these advantages, make it locates the domain got relatively accurate result indoors.

 

Exceed a broadband technology of indoor fixed position often uses TDOA to demonstrate algorithm of range finding fixed position, the time that arrives through signal namely is wrong, exceed broadband system to comprise generation through what hyperbola across will locate, blast off, receive, processing is extremely narrow the radio system of pulse signal. And exceed a broadband indoor location system includes label of reference of UWB receiver, UWB and active UWB ticket. By UWB receiver receives the UWB signal that label transmits in fixed position process, through filtering electromagnetic wave transmits all sorts of noise interference of the be mingled with in the process, get containing the signal of effect information, processing unit undertakes range finding locates computation is analysed in the center of repass.

 

Exceed a broadband to be able to be used at indoor and exact location, for example motion of the positional discovery of battlefield soldier, robot dogs etc. Exceed broadband system and traditional tape system photograph to compare, have penetration strong, power comsumption effect of low, interference rejection good, security tall, system is complex degree low, can offer essence of life to define the good point such as a precision. Accordingly, the fixed position that exceeds broadband technology to be able to apply at indoor and dormant mobile perhaps object and person dogs with navigation, and can offer very accurate fixed position precision. The technical method that uses according to different company or algorithm are different, precision can maintain in 0.1 M~0.5 M.

 

4, technology of geomagnetic fixed position

 

The earth can regard a magnetism idol as extremely, among them one extremely around geographical arctic, another extremely around geographical antarctic. Geomagnetic field includes main magnetic field and metabolic magnetic field two parts. Main magnetic field is the body of geomagnetic field, traceable earth is in-house, stabler, attribute part of static magnetic field. Metabolic magnetic field includes all sorts of short-term change of geomagnetic field, main traceable earth is in-house, photograph contrast is fainter.

 

Structure of contemporary architectural ferroconcrete will be right inside local limits geomagnetic generation is disturbed, compass also can be affected possibly accordingly. For in principle, the magnetic field environment with even blame can differ because of its method the outcome of magnetic field observation with different generation. And the fixed position technology of this kind of IndoorAtlas that be called, use terrestrial magnetism just about indoors this kind of change undertakes indoor navigation, and navigation precision can have been achieved 0.1 meters go to 2 meters.

 

Use this kind to the technology has the process of navigation or show a trouble a bit nevertheless. In the map cloud that you need to upload indoor floor plane figure IndoorAtlas to offer first, next you need to use its the geomagnetic field that mobile client end records target ground to nod different position on the spot. The geomagnetic data of the record can be uploaded to come by client end high in the clouds, such other person ability use the terrestrial magnetism that already had recorded to undertake accurate and indoor navigation.

 

Baidu 2014 the strategy invested technology of geomagnetic fixed position to develop business IndoorAtlas, announced to its are used in the map application in oneself in June 2015 technology of geomagnetic fixed position, technology of this technology and Wi-Fi heat map, will inertial navigation is used jointly. Precision is tall, in publicizing commercial application, can reach level of rice class position, but interference of source of signal of the report that magnetism signal is changed easily ceaselessly in the environment, magnetism, position result is not stable, precision can suffer an effect.

 

5, technology of ultrasonic fixed position

 

Fixed position technology passes ultrasonic to install many ultrasonic loudspeaker indoors, issue the supersonic signal that can be detected by terminal microphone. The arrival time that passes different sound wave is wrong, speculation gives a Ning of terminal.

 

The deferent speed as a result of sound wave is far under electromagnetic wave, difficulty of its system implementation is very small, can realize wireless synchronism of the system very simply, send with ultrasonic transmitter next, sink uses microphone to receive, him operation position can.

 

Because the rate of sound wave is lower, the time that deferent and identical content needs is longer, the means gift that passes similar TDoA only acquires larger systematic capacity.

 

6, technology of ZigBee indoor fixed position

 

This technology is to pass a certain number of group network is formed between the blind node that needs fixed position and a referenced node of foregone position and gateway, every tiny blind coordinates communication to locate in order to come true entirely each other between node.

 

ZigBee is a kind of burgeoning stone’s throw, low speed leads wireless network technology, these sensor need very few energy only, transmit data another node from a node through radio wave with the means of relay, regard the communication of a low power comsumption and low cost as the system, the work efficiency of ZigBee is very tall. But the signal of ZigBee transmits the effect that suffers much diameter effect and shift very big, and fixed position precision depends on density of source of channel physics character, signal, environment and algorithmic accuracy, the cost that creates fixed position software is higher, increase a space very big still.

 

On guard of the member that ZigBee indoor fixed position has been regarded as a person by a lot of large plants and workshop manages systematic place to use.

 

7, technology of infrared fixed position

 

Infrared ray is the between radio wave and visible light wave electromagnetic wave between a kind of wavelengh. Infrared ray is indoor the principle that fixed position technology locates is, infrared label fires the infra-red ray of modulation, through installation indoors optical sensor is received have fixed position. Although infrared ray is had relative to precision of taller indoor fixed position, but cannot cross fraise as a result of the light, make infra-red ray only can apparent distance travels. Linear apparent distance and transmission distance is shorter this two big main drawback make his indoor the effect of fixed position is very poor. Cannot work normally when the label is put in the pocket to perhaps have wall etc keep out, need installs receving antenna in every room, corridor, cost is higher. Accordingly, infrared ray suits stone’s throw transmission only, and easy by fluorescent lamp or the lamplight interference inside the room, there is limitation on exact location.

 

Typical infrared ray is indoor location system Activebadges makes wait for measure object attach an electron mark, this label passes infra-red catapult to indoor and fixed placement infra-red receiver cycle sends this to wait for measure content exclusive ID, wired network will count receiver repass to be defeated by a database as it is said. Power comsumption of technology of this fixed position is bigger and often can get of indoor wall body or object cut off, practical inferior. If also can realize infrared ray and union of ultrasonic technology photograph fixed position function conveniently. Spark with infrared ray fixed position signal makes the ultrasonic emitter of reference point to wait for measure bit of emissive ultrasonic, applied TOA is basic and algorithmic, adopt fixed position of clock range finding. Reduced power comsumption on one hand, avoided ultrasonic to reflex type to locate the technology transmits the blemish with short distance on the other hand. Make infra-red technology and ultrasonic technology advantage complementary.

 

8, technology of blue tooth fixed position

 

Blue tooth technology has fixed position through measuring signal intensity. This is the wireless transmission technology of low power comsumption of a kind of stone’s throw, install proper blue tooth local area network to receive a point indoors, configure the network into the mode of fundamental network join that is based on much user, assure this to blue tooth local area network receives a point is from beginning to end slightly net (of Piconet) advocate equipment, with respect to the positional information that can obtain an user.

 

Blue tooth technology basically applies Yu Xiaofan to surround fixed position, for example monolayer hall or storehouse. Blue tooth is indoor the advantage with fixed position the biggest technology is equipment bulk small, easily compositive in PDA, PC and mobile phone, popularize very easily accordingly. Theoretic, compositive to hold the user of terminal unit of shift of blue tooth function, want the open of blue tooth function of equipment only, indoor location system can be opposite blue tooth its undertake the position is judged. When using this technology to make indoor stone’s throw locate discover equipment easily and signal transmits the effect that does not suffer apparent distance. The technical method that uses according to different company or algorithm are different, precision can maintain in 3 M~15 M.

 

9, GPS and north fight the fixed position technology such as the satellite

 

North fights satellitic fixed position is Chinese own research and development, use earthly synchronism satellite to provide round-the-clock, regional satellitic location system for the user. It can define a goal quickly or the user is located situation, provide navigation information to user and director branch.

 

North fights satellitic navigation system to be in the short of Wenshui River 2008 plain the earthquake is aseismatic main effect was produced in providing disaster relief. Below the circumstance that in place communication establishment is damaged badly, fight satellitic system to come true to nod a contact between departmental door each through north, decide accurately the position of each army providing disaster relief, so that amount to new rescuing job according to the situation of a disaster and nowadays.

 

Show level north to fight a satellite to apply at civil comparison little, and also can see on market north fights mobile phone and north to fight car navigation.

 

10, base station location technology

 

Base station location applies at mobile phone user commonly, service of location of station of mobile phone radical calls mobile position the service again (LBS——Location Based Service) , it is the network that carries business of telegraphic and mobile operation (be like GSM net) the positional information that gets mobile terminal user () of coordinate of longitude and latitude, below the support of electronic map platform, provide the professional work of a kind of appreciation of corresponding service for the user, for example at present Chinese shift moves what feeling region offers to move feeling position to inquire a service to wait.

 

Because GPS fixed position compares cost report, so base station location is GPS equipment common function. But base station location precision is inferior, the error that goes to 2000 meters in 100 meters commonly.

 

 

Allude besides above, a few does the sort that will see fixed position technology at present have to get on 100 kinds even, and every kinds of actor defect that locates the technology has him and suitable applied setting. After all which kinds of technology can win out finally, return unknown now, remain of time of whole industry application examine.

 

(origin: LBS)