CN116095828A - Indoor wireless positioning system and method based on power detection - Google Patents
Indoor wireless positioning system and method based on power detection Download PDFInfo
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- CN116095828A CN116095828A CN202310128128.5A CN202310128128A CN116095828A CN 116095828 A CN116095828 A CN 116095828A CN 202310128128 A CN202310128128 A CN 202310128128A CN 116095828 A CN116095828 A CN 116095828A
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W64/00—Locating users or terminals or network equipment for network management purposes, e.g. mobility management
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S11/00—Systems for determining distance or velocity not using reflection or reradiation
- G01S11/02—Systems for determining distance or velocity not using reflection or reradiation using radio waves
- G01S11/06—Systems for determining distance or velocity not using reflection or reradiation using radio waves using intensity measurements
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
- G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
- G01S5/0294—Trajectory determination or predictive filtering, e.g. target tracking or Kalman filtering
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
- H04W4/30—Services specially adapted for particular environments, situations or purposes
- H04W4/33—Services specially adapted for particular environments, situations or purposes for indoor environments, e.g. buildings
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- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
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Abstract
The invention discloses an indoor wireless positioning system and method based on power detection, wherein the system comprises the following steps: the device comprises a data collection module, a data processing module and a data filtering module; the wireless AP data collection module is used for collecting data information of RSSI and RTT in the wireless AP; the wireless AP data processing module is used for processing the data information of RSSI and RTT in the wireless AP to obtain the RSSI distance and the RTT mean value distance; and the wireless AP data filtering module is used for judging whether all RTTs come from the same channel according to the RSSI distance and the RTT average value distance, and filtering the RTT to obtain the physical position coordinates of the terminal. The invention adopts the data collection module, the data processing module and the data filtering module to filter RTT obtained by the data collection module, ensures that RTT distance obtained by the data processing module is subjected to Kalman filtering when the calculated terminal coordinates are the RTT used, and avoids the influence of noise on the terminal position.
Description
Technical Field
The invention relates to the field of wireless positioning, in particular to an indoor wireless positioning system and method based on power detection.
Background
Currently, due to the rapid development of communication technology, wireless positioning systems have grown with market demands for positioning. Positioning technology is closely related to people's life and has received extensive attention. From a range classification of positioning, positioning techniques can be classified into outdoor positioning (typically GPS positioning) and indoor positioning (typically ultrasound, sound wave, wiFi, infrared, RFID, UWB, etc.). Indoor positioning is still in early development, however, although a wide variety of indoor positioning technologies are presented, a large-scale service system is not established at present.
Therefore, a plurality of wireless positioning service modes are generated, fingerprint positioning is that is based on the indoor wireless local area network positioning of the position fingerprint, the implementation of the fingerprint positioning system is realized by two stages, namely a pre-sampling stage and a post-positioning stage, the basic idea of the positioning is that Wi-Fi signal intensity distribution of each positioning point in a positioning scene is provided with fixed characteristics and does not change with time, the signal intensity characteristics of the positioning points have a one-to-one mapping relation with physical position information of the positioning points unexpectedly, therefore, if the signal characteristics at each position are recorded in a pre-sampling mode, a corresponding database is generated in actual application, wi-Fi signal characteristics of the positioning points are recorded by a series of characteristic tables, the detailed position information of the terminal can be obtained by combining a certain matching algorithm in an actual positioning mode, and the fingerprint positioning mode has the greatest advantages that: the Wi-Fi signal condition of the positioning scene can be truly reflected by the sampling data, and the real-time positioning of the terminal position in the positioning scene can be completed under the condition that specific medium attenuation parameters are not known in advance, so that the fingerprint positioning has high scene applicability, and the fingerprint positioning has a certain development prospect.
However, in the specific use process, once the positioning environment is changed, such as the wireless AP angle moves, resampling is required, which causes a great deal of labor waste and inaccuracy of positioning accuracy, so that the efficiency of positioning is reduced.
For the problems in the related art, no effective solution has been proposed at present.
Disclosure of Invention
Aiming at the problems in the related art, the invention provides an indoor wireless positioning system and method based on power detection, so as to overcome the technical problems existing in the prior related art.
For this purpose, the invention adopts the following specific technical scheme:
according to one aspect of the present invention, there is provided an indoor wireless location system based on power detection, the system comprising: the wireless AP data acquisition module, the wireless AP data processing module and the wireless AP data filtering module;
the wireless AP data collection module is used for collecting data information of RSSI and RTT in the wireless AP;
the wireless AP data processing module is used for processing the data information of RSSI and RTT in the wireless AP, obtaining the RSSI distance and RTT mean value distance, and estimating the position of the terminal;
the wireless AP data filtering module is used for judging whether all RTTs come from the same channel according to the RSSI distance and the RTT average value distance, and filtering the RTT to obtain the physical position coordinates of the terminal.
Further, the measurement data collection module comprises a measurement request issuing module and a measurement data collection module;
the measurement request issuing module is used for positioning the deployment and switching of wireless AP channels in an indoor environment and participating in the selection of the positioning wireless AP;
and the measurement data collection module is used for reporting the parameter information of the terminal, APS around the wireless AP and RSSI and RTT collected by the wireless APs participating in the terminal positioning to the positioning server by the wireless AP.
Further, the wireless AP data processing module comprises a transformation module, an RSSI distance calculation module, an RTT calculation module and a terminal coordinate calculation module;
the transformation module is used for converting the channel state information into time domain power delay data and obtaining the data of RSSI and RTT through the time domain power delay data;
the RSSI distance calculation module is used for calculating the distance of the RSSI from the collected RSSI data through a decay formula;
the RTT calculation module is used for calculating the RTT distance of the collected RTT data through an attenuation formula;
the terminal coordinate calculation module is used for calculating the actual space coordinate of the terminal by utilizing a Gaussian Newton algorithm according to the distance between the RSSI and the RTT.
Further, the converting the channel state information into time domain power delay data, and obtaining the data of the RSSI and RTT through the time domain power delay data includes the following steps:
channel state information derived by the wireless AP chip;
the channel state information is subjected to wavelet transformation algorithm to obtain time domain power delay data;
and analyzing the time domain power delay data and obtaining the data of RSSI and RTT collected by the wireless AP positioned by the terminal.
Further, the wavelet transformation algorithm comprises the following conversion steps:
defining an initial threshold and a step size of channel state information;
starting from an initial threshold value, continuously updating the threshold value every time when a step length is added, setting a wavelet coefficient value with an absolute value smaller than the threshold value to zero, and obtaining the number of non-zero values;
when the non-zero value sum difference obtained by the two adjacent thresholds is smaller than a parameter of certain channel state information, a required threshold is obtained, the smaller threshold of the two thresholds is selected, and the threshold is defined as time domain power delay data.
Further, the calculation formula of the attenuation formula is as follows:
in the method, in the process of the invention,
for the received signal strength, +.>
For the signal strength received at one meter, +.>
Is constant and varies with the environment, < >>
Is the distance of the mobile terminal from the wireless AP.
Further, the calculating the actual space coordinate of the terminal according to the distance between the RSSI and the RTT by using the Gauss Newton algorithm includes the following steps:
acquiring the distance between the RSSI in the wireless AP and the distance between the RTT;
the distance between the RSSI and the distance between the RTT are imported into an equation set of a Gaussian Newton algorithm;
solving a nonlinear equation set through multiple iterations, and enabling the sum of squares of errors of solutions of the equation set to be the lowest;
marking according to the solution of the equation set, and estimating the position of the terminal.
Further, the wireless AP data filtering module comprises an RTT filtering module and a Kalman filtering module;
the RTT filtering module is used for judging whether all RTTs come from the same channel according to the RSSI distance and the RTT average distance, and filtering RTT to obtain Kalman filtered RTT;
and the Kalman filtering module is used for carrying out Kalman filtering on the RTT distance.
Further, the kalman filtering the RTT distance includes the following steps:
acquiring corresponding RTT (round trip time) capable of carrying out Kalman filtering, and calculating a corresponding RTT distance;
inputting the calculated RTT into Kalman filtering, eliminating the influence of accidental noise by Kalman filtering, and obtaining more effective RTT distance;
inputting the coordinate of RTT into a terminal coordinate calculation module to obtain the physical position coordinate of the terminal;
and returning to the positioning server, and displaying the positioning server to the user in a webpage mode.
According to another aspect of the present invention, there is also provided an indoor wireless positioning method based on power detection, the indoor wireless positioning method including the steps of:
s1, acquiring data information of RSSI and RTT in a wireless AP;
s2, processing data information of RSSI and RTT in the wireless AP, obtaining an RSSI distance and an RTT average distance, and estimating the position of the terminal;
and S3, judging whether all RTTs come from the same channel according to the RSSI distance and the RTT average distance, and filtering the RTT to obtain the physical position coordinates of the terminal.
The beneficial effects of the invention are as follows:
1. the wireless positioning system is designed into a unique environment-oriented wireless AP deployment and switching scheme for improving the positioning accuracy of the terminal, the wireless positioning system improves the positioning accuracy of the terminal, and discards triangle positioning commonly used in the market at present, the wireless positioning system is realized by adopting a convex quadrilateral wireless AP selection positioning algorithm mode, and the measurement data collection module is used for reporting the MAC address, the operating system, the manufacturer, the model, the encryption mode, the frequency band and APS around the wireless AP of the terminal and a series of RSSI and RTT collected by related wireless APs participating in the positioning of the terminal to a positioning server by the wireless AP on the basis of a measurement request issuing module.
2. The invention adopts the data collection module, the data processing module and the data filtering module to filter RTT obtained by the data collection module so as to ensure that RTT distance obtained by the data processing module is Kalman filtered when the calculated terminal coordinate is the used RTT, thereby avoiding the influence of accidental noise on the final terminal position.
3. When the wireless AP is selected, the invention enters a terminal RSSI and RTT collecting stage to obtain channel state information after the wireless AP is positioned and interacted with the terminal, the channel state information is obtained and then enters a wavelet transformation algorithm for transformation, a power delay file PDP is obtained, the power RSSI on a direct path and an attenuation coefficient in a calculated attenuation formula are obtained, when the wavelet transformation algorithm is transformed, the RSSI distance calculation is carried out, a series of RSSI distances are calculated according to the attenuation formula, and the effective RSSI distance is determined by adding and subtracting constants in an acceptable error range according to the average value of all the RSSI distances.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic block diagram of an indoor wireless location system based on power detection according to an embodiment of the present invention.
In the figure:
1. a wireless AP data collection module; 2. a wireless AP data processing module; 3. and the wireless AP data filtering module.
Description of the embodiments
For the purpose of further illustrating the various embodiments, the present invention provides the accompanying drawings, which are a part of the disclosure of the present invention, and which are mainly used to illustrate the embodiments and, together with the description, serve to explain the principles of the embodiments, and with reference to these descriptions, one skilled in the art will recognize other possible implementations and advantages of the present invention, wherein elements are not drawn to scale, and like reference numerals are generally used to designate like elements.
According to the embodiment of the invention, an indoor wireless positioning system and method based on power detection are provided.
The present invention will be further described with reference to the accompanying drawings and detailed description, as shown in fig. 1, an indoor wireless positioning system based on power detection according to an embodiment of the present invention, the system includes: the wireless AP data collection module 1, the wireless AP data processing module 2 and the wireless AP data filtering module 3;
the wireless AP data collection module 1 is used for collecting data information of RSSI and RTT in the wireless AP;
in one embodiment, the measurement data collection module includes a measurement request issuing module and a measurement data collection module;
the measurement request issuing module is used for positioning the deployment and switching of wireless AP channels in an indoor environment and participating in the selection of the positioning wireless AP;
and the measurement data collection module is used for reporting the parameter information of the terminal, APS around the wireless AP and RSSI and RTT collected by the wireless APs participating in the terminal positioning to the positioning server by the wireless AP.
Specifically, in order to improve the positioning accuracy of the terminal, the wireless positioning system designs a unique environment-oriented wireless AP deployment and switching scheme, the wireless positioning system improves the positioning accuracy of the terminal, and discards triangle positioning commonly used in the market at present, the wireless positioning system is realized by adopting a convex quadrilateral wireless AP selection positioning algorithm mode, and the measurement data collection module is formed by reporting the MAC address, the operating system, the manufacturer, the model, an encryption mode, a frequency band and APS (map) of the terminal and a series of RSSI and RTT collected by related wireless APs participating in the positioning of the terminal to a positioning server by the wireless AP on the basis of a measurement request issuing module.
In addition, in the specific application, a mobile terminal user accesses a wireless network legal person in a positioning environment through a wireless scanning technology and through modes such as MAC address authentication and the like to initiate a terminal positioning request, a positioning server initiates message interaction for inquiring terminal information to a terminal associated wireless AP, the associated wireless AP returns information such as manufacturer, working channel and the like of the terminal to the positioning server, after data collection is completed, wireless APs nearby the associated wireless AP can be enabled to switch channels, when the channel switching is completed, a wireless AP selection function is entered, and wireless APs participating in positioning are determined.
Further, several indoor wireless location technology profiles:
1. the infrared positioning technology generally comprises two types, wherein one type is that an infrared IR mark is used for a target point to be detected, a modulated infrared signal is emitted, and an optical sensor is arranged at a known position indoors to receive the infrared signal for positioning; still another is to locate a moving object in a space to be measured by combining a plurality of transmitters and receivers into a net structure. At present, the infrared technology is very mature, and the infrared positioning has relatively high precision in the indoor positioning field. However, the infrared ray sight distance transmission characteristic is poor in penetrability, the infrared ray sight distance transmission characteristic cannot work normally after being blocked by an obstacle, and some dust smoke or other light sources and other factors can also obviously influence infrared detection. The infrared transmission distance is short, the directivity is strong, the signal shielding problem needs to be considered mainly in the process of layout, the layout is relatively complex, the requirement on the environment is high, and the positioning application range is limited.
2. The WiFi indoor positioning system can be divided into wireless AP interval positioning and signal RSSI fingerprint matching positioning. The former is often tens of meters in positioning error due to low cost, because the AP position is inaccurate or cannot accurately calculate the distance to the AP. The latter needs to establish the corresponding fingerprint database, and the intensity of signal is big to positioning accuracy's influence to the database maintenance requirement is high, is not suitable for most ordinary places to use. Currently, wiFi communication generally only covers areas within a radius of 90 meters, so WiFi is only suitable for indoor positioning in a small range. Meanwhile, other signal interference is easy to receive, and the positioning power consumption is high.
3. Bluetooth positioning technology is the same as wifi positioning and is suitable for short-distance wireless positioning. The Bluetooth indoor positioning technology has the advantages of small equipment volume, low power consumption, easy integration in mobile phones or other intelligent equipment, and no influence of sight distance. But bluetooth working distance is shorter, and the interference of noise signal is big, and stability is relatively poor.
4. The radio frequency identification technology is that the RFID positioning system is divided into interval positioning adopting an access control mode and positioning based on the signal intensity of a tag. The positioning error based on the label signal intensity is about 1m on average, so that the arrangement of a large number of reference labels is difficult to popularize in a large range. And the interval positioning accuracy of the access control mode is lower. Generally, RFID communication distance is within tens of meters, which has the advantages of low cost, non-line-of-sight propagation and the like, but the current lack of a complete standard system, most of which can only be used, and privacy disclosure problems are easily related.
5. The ultra-wideband positioning technology is a carrier-free communication technology. The bandwidth can reach GHz level by utilizing non-sinusoidal wave narrow pulse transmission data of nanosecond to subnanosecond level. Compared with the traditional narrow-band system, the UWB has the advantages of small power consumption, strong penetrating power, high safety, strong multipath resistance and the like. Therefore, UWB technology can be used for indoor stationary or moving object and person location tracking, but standardization is severely delayed relative to WiFi, bluetooth, zigBee and RFID, and the communication distance is generally less than 10 meters, the dynamic range is relatively small, the cost is high, and the difficulty of industrial popularization is great.
6. The ZigBee technology is a low-rate short-distance local area network positioning technology based on the IEEE802.15.4 standard. Positioning accuracy can typically be up to 3m. The method has the main advantages of low power consumption, low cost and high communication efficiency, and has the defect that the positioning accuracy is greatly influenced by the environment.
7. The ultrasonic positioning technology is generally based on the ultrasonic ranging principle, an ultrasonic positioning system can be composed of a plurality of transmitters and receivers, the positions of the transmitting points to be measured are calculated by combining signals received by the receivers arranged at different known positions with the corner relationship, or conversely, one receiver respectively receives ultrasonic signals of the transmitters at different known positions to calculate the positions of the receiving points, and can also be combined with a reflection ranging method or other complex combinations to perform ranging positioning, so that ultrasonic waves can reach indoor positioning precision of centimeter level, the structure is relatively simple, although the ultrasonic waves have certain penetrating capacity and strong anti-interference capacity, the ultrasonic waves in the air attenuate fast, the ultrasonic positioning system is only suitable for short-distance small-sized occasions, the influence of non-line-of-sight propagation and multipath effects is obvious, and the hardware cost required for reducing the influence is high.
The wireless AP data processing module 2 is used for processing the data information of RSSI and RTT in the wireless AP, obtaining the RSSI distance and RTT mean distance, and estimating the position of the terminal;
in one embodiment, the wireless AP data processing module includes a transformation module, an RSSI distance calculation module, an RTT calculation module, and a terminal coordinate calculation module;
the transformation module is used for converting the channel state information into time domain power delay data and obtaining the data of RSSI and RTT through the time domain power delay data;
the RSSI distance calculation module is used for calculating the distance of the RSSI from the collected RSSI data through a decay formula;
the RTT calculation module is used for calculating the RTT distance of the collected RTT data through an attenuation formula;
the terminal coordinate calculation module is used for calculating the actual space coordinate of the terminal by utilizing a Gaussian Newton algorithm according to the distance between the RSSI and the RTT.
In one embodiment, the converting the channel state information into time domain power delay data and obtaining the data of RSSI and RTT through the time domain power delay data includes the steps of:
channel state information derived by the wireless AP chip;
the channel state information is subjected to wavelet transformation algorithm to obtain time domain power delay data;
and analyzing the time domain power delay data and obtaining the data of RSSI and RTT collected by the wireless AP positioned by the terminal.
In one embodiment, the wavelet transform algorithm comprises the following conversion steps:
defining an initial threshold and a step size of channel state information;
starting from an initial threshold value, continuously updating the threshold value every time when a step length is added, setting a wavelet coefficient value with an absolute value smaller than the threshold value to zero, and obtaining the number of non-zero values;
when the non-zero value sum difference obtained by the two adjacent thresholds is smaller than a parameter of certain channel state information, a required threshold is obtained, the smaller threshold of the two thresholds is selected, and the threshold is defined as time domain power delay data.
Specifically, the wireless AP signals are decomposed through orthogonal wavelet transformation, the wireless AP signals are processed in a hierarchical threshold mode, the scaling factor of RSSI is large, wavelet comparison is represented, and the signal profile is measured; the scaling factor of RTT is small, the wavelet is narrow, the detail of the signal is measured, so the RSSI has higher amplitude value, and the lower frequency echo pulse keeps a more detailed profile; and RTT has a relatively low amplitude value, only a high-frequency detail part of the echo pulse is reserved, and effective measures are taken according to the characteristics, so that adverse effects in RSSI and RTT are filtered.
In one embodiment, the attenuation formula is calculated as:
in the method, in the process of the invention,
for the received signal strength, +.>
For the signal strength received at one meter, +.>
Is constant and varies with the environment, < >>
Is the distance of the mobile terminal from the wireless AP.
In one embodiment, the calculating the actual space coordinate of the terminal according to the distance between the RSSI and the distance between the RTT using the gauss newton algorithm includes the following steps:
acquiring the distance between the RSSI in the wireless AP and the distance between the RTT;
the distance between the RSSI and the distance between the RTT are imported into an equation set of a Gaussian Newton algorithm;
solving a nonlinear equation set through multiple iterations, and enabling the sum of squares of errors of solutions of the equation set to be the lowest;
marking according to the solution of the equation set, and estimating the position of the terminal.
Specifically, when the wireless AP participating in positioning is selected, entering into a terminal RSSI and RTT collecting stage to obtain positioning nothingThe method comprises the steps that channel state information after interaction of a line AP and a terminal is obtained, the channel state information is transformed by a wavelet transformation algorithm, a power delay file PDP is obtained, and power RSSI on a direct path and attenuation coefficients in an attenuation calculation formula are obtained
After the wavelet transformation algorithm is finished, RSSI distance calculation is carried out, a series of RSSI distances are calculated according to a decay formula, and the effective RSSI distance is determined by adding and subtracting a constant within an acceptable error range from the average value of all the RSSI distances.
In addition, the basic idea of the Gaussian Newton method is to use a Taylor series expansion to approximately replace a nonlinear regression model, then repeatedly iterate for a plurality of times to correct the regression coefficient, so that the regression coefficient continuously approximates to the optimal regression coefficient of the nonlinear regression model, and finally, the residual square sum of the original model is minimized. The general procedure for gauss newton's method is: the initial value is selected by three methods, namely, the initial value is selected according to the past experience; secondly, obtaining an initial value by a segmentation method; thirdly, obtaining an initial value of a linearized nonlinear regression model through linear transformation and then performing a least squares method.
The wireless AP data filtering module 3 is configured to determine whether all RTTs are from the same channel according to the RSSI distance and the RTT mean distance, and filter the RTTs to obtain physical location coordinates of the terminal.
In one embodiment, the wireless AP data filtering module includes an RTT filtering module and a kalman filtering module;
the RTT filtering module is used for judging whether all RTTs come from the same channel according to the RSSI distance and the RTT average distance, and filtering RTT to obtain Kalman filtered RTT;
and the Kalman filtering module is used for carrying out Kalman filtering on the RTT distance.
In one embodiment, the kalman filtering the RTT distance includes the steps of:
acquiring corresponding RTT (round trip time) capable of carrying out Kalman filtering, and calculating a corresponding RTT distance;
inputting the calculated RTT into Kalman filtering, eliminating the influence of accidental noise by Kalman filtering, and obtaining more effective RTT distance;
inputting the coordinate of RTT into a terminal coordinate calculation module to obtain the physical position coordinate of the terminal;
and returning to the positioning server, and displaying the positioning server to the user in a webpage mode.
Specifically, the kalman filter is an algorithm for optimally estimating the state of a system by solving an equation of the state of a linear system and inputting and outputting observation data through the system. Since the observed data includes the effects of noise and interference in the system, the optimal estimate can also be considered a filtering process. The effect of the kalman filter is to make the dynamic data appear as a smoothly varying result. And a Kalman filter is arranged for calculating the distance di from each AP to each terminal, so that the Kalman filter shows a smooth change, and the influence of accidental noise on the final terminal position is avoided. The distance from the terminal to the AP after the Kalman filtering treatment eliminates the influence of accidental noise.
According to another embodiment of the present invention, there is also provided an indoor wireless positioning method based on power detection, the indoor wireless positioning method including the steps of:
s1, acquiring data information of RSSI and RTT in a wireless AP;
s2, processing data information of RSSI and RTT in the wireless AP, obtaining an RSSI distance and an RTT average distance, and estimating the position of the terminal;
and S3, judging whether all RTTs come from the same channel according to the RSSI distance and the RTT average distance, and filtering the RTT to obtain the physical position coordinates of the terminal.
In summary, by means of the above technical solution of the present invention, in order to improve the positioning accuracy of the terminal, the wireless positioning system of the present invention designs a unique deployment and switching scheme of wireless APs defined as environment, the wireless positioning system improves the positioning accuracy of the terminal, and eliminates triangle positioning commonly used in the market at present, and is implemented by adopting a convex quadrilateral wireless AP selection positioning algorithm, and the measurement data collection module is implemented by reporting, to the positioning server, the MAC address, the operating system, the manufacturer, the model, the encryption mode, the frequency band and APs (maps) around the wireless APs of the terminal and a series of RSSI and RTT collected by the related wireless APs involved in the positioning of the terminal, by the wireless APs on the terminal on the basis of the measurement request issuing module; the invention adopts the data collection module 1, the data processing module 2 and the data filtering module 3 to filter RTT obtained by the data collection module so as to ensure that RTT distance obtained by the data processing module is Kalman filtered when the calculated terminal coordinate is the used RTT, thereby avoiding the influence of accidental noise on the final terminal position; when the wireless AP is selected, the invention enters a terminal RSSI and RTT collecting stage to obtain channel state information after the wireless AP is positioned and interacted with the terminal, the channel state information is obtained and then enters a wavelet transformation algorithm for transformation, a power delay file PDP is obtained, the power RSSI on a direct path and an attenuation coefficient in a calculated attenuation formula are obtained, when the wavelet transformation algorithm is transformed, the RSSI distance calculation is carried out, a series of RSSI distances are calculated according to the attenuation formula, and the effective RSSI distance is determined by adding and subtracting constants in an acceptable error range according to the average value of all the RSSI distances.
The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the invention.
Claims (10)
1. An indoor wireless location system based on power detection, the system comprising: the wireless AP data acquisition module, the wireless AP data processing module and the wireless AP data filtering module;
the wireless AP data collection module is used for collecting data information of RSSI and RTT in the wireless AP;
the wireless AP data processing module is used for processing the data information of RSSI and RTT in the wireless AP, obtaining the RSSI distance and RTT mean value distance, and estimating the position of the terminal;
the wireless AP data filtering module is used for judging whether all RTTs come from the same channel according to the RSSI distance and the RTT average value distance, and filtering the RTT to obtain the physical position coordinates of the terminal.
2. The indoor wireless positioning system based on power detection of claim 1, wherein the measurement data collection module comprises a measurement request issuing module and a measurement data collection module;
the measurement request issuing module is used for positioning the deployment and switching of wireless AP channels in an indoor environment and participating in the selection of the positioning wireless AP;
and the measurement data collection module is used for reporting the parameter information of the terminal, APS around the wireless AP and RSSI and RTT collected by the wireless APs participating in the terminal positioning to the positioning server by the wireless AP.
3. The indoor wireless positioning system based on power detection of claim 1, wherein the wireless AP data processing module comprises a transformation module, an RSSI distance calculation module, an RTT calculation module, and a terminal coordinate calculation module;
the transformation module is used for converting the channel state information into time domain power delay data and obtaining the data of RSSI and RTT through the time domain power delay data;
the RSSI distance calculation module is used for calculating the distance of the RSSI from the collected RSSI data through a decay formula;
the RTT calculation module is used for calculating the RTT distance of the collected RTT data through an attenuation formula;
the terminal coordinate calculation module is used for calculating the actual space coordinate of the terminal by utilizing a Gaussian Newton algorithm according to the distance between the RSSI and the RTT.
4. A power detection based indoor wireless location system according to claim 3, wherein the converting the channel state information into time domain power delay data and obtaining the data of RSSI and RTT from the time domain power delay data comprises the steps of:
channel state information derived by the wireless AP chip;
the channel state information is subjected to wavelet transformation algorithm to obtain time domain power delay data;
and analyzing the time domain power delay data and obtaining the data of RSSI and RTT collected by the wireless AP positioned by the terminal.
5. The indoor wireless location system based on power detection of claim 4, wherein the step of converting the wavelet transform algorithm comprises:
defining an initial threshold and a step size of channel state information;
starting from an initial threshold value, continuously updating the threshold value every time when a step length is added, setting a wavelet coefficient value with an absolute value smaller than the threshold value to zero, and obtaining the number of non-zero values;
when the non-zero value sum difference obtained by the two adjacent thresholds is smaller than a parameter of certain channel state information, a required threshold is obtained, the smaller threshold of the two thresholds is selected, and the threshold is defined as time domain power delay data.
6. The indoor wireless location system based on power detection of claim 5, wherein the equation of the attenuation equation is:
in the method, in the process of the invention,
for the received signal strength, +.>
For the signal strength received at one meter, +.>
Is constant and varies with the environment, < >>
Is the distance of the mobile terminal from the wireless AP.
7. The indoor wireless location system based on power detection of claim 6, wherein the calculating the actual space coordinates of the terminal using the gauss newton algorithm according to the distance of the RSSI and the distance of the RTT comprises the steps of:
acquiring the distance between the RSSI in the wireless AP and the distance between the RTT;
the distance between the RSSI and the distance between the RTT are imported into an equation set of a Gaussian Newton algorithm;
solving a nonlinear equation set through multiple iterations, and enabling the sum of squares of errors of solutions of the equation set to be the lowest;
marking according to the solution of the equation set, and estimating the position of the terminal.
8. The indoor wireless location system based on power detection of claim 1, wherein the wireless AP data filtering module comprises an RTT filtering module and a kalman filtering module;
the RTT filtering module is used for judging whether all RTTs come from the same channel according to the RSSI distance and the RTT average distance, and filtering RTT to obtain Kalman filtered RTT;
and the Kalman filtering module is used for carrying out Kalman filtering on the RTT distance.
9. The indoor wireless location system based on power detection of claim 8, wherein said kalman filtering RTT distance comprises the steps of:
acquiring corresponding RTT (round trip time) capable of carrying out Kalman filtering, and calculating a corresponding RTT distance;
inputting the calculated RTT into Kalman filtering, eliminating the influence of accidental noise by Kalman filtering, and obtaining more effective RTT distance;
inputting the coordinate of RTT into a terminal coordinate calculation module to obtain the physical position coordinate of the terminal;
and returning to the positioning server, and displaying the positioning server to the user in a webpage mode.
10. An indoor wireless positioning method based on power detection for implementing the indoor wireless positioning system based on power detection as claimed in any one of claims 1-9, characterized in that the indoor wireless positioning method comprises the following steps:
s1, acquiring data information of RSSI and RTT in a wireless AP;
s2, processing data information of RSSI and RTT in the wireless AP, obtaining an RSSI distance and an RTT average distance, and estimating the position of the terminal;
and S3, judging whether all RTTs come from the same channel according to the RSSI distance and the RTT average distance, and filtering the RTT to obtain the physical position coordinates of the terminal.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100135178A1 (en) * | 2008-11-21 | 2010-06-03 | Qualcomm Incorporated | Wireless position determination using adjusted round trip time measurements |
| US20140187257A1 (en) * | 2013-01-03 | 2014-07-03 | Qualcomm Incorporated | Inter-ap distance estimation using crowd sourcing |
| US20150131460A1 (en) * | 2013-11-13 | 2015-05-14 | Qualcomm Incorporated | Method and apparatus for using rssi and rtt information for choosing access points to associate with |
| US20150146553A1 (en) * | 2013-01-29 | 2015-05-28 | Qualcomm Incorporated | System and method for deploying an rtt-based indoor positioning system |
| US20180252795A1 (en) * | 2017-03-03 | 2018-09-06 | Qualcomm Incorporated | Enhancing indoor positioning using passive acoustic tags |
| KR20220047491A (en) * | 2020-10-09 | 2022-04-18 | 주식회사 와따 | Indoor location idendifying system |
| KR20220077542A (en) * | 2020-12-02 | 2022-06-09 | 주식회사 와따 | Indoor location idendifying system based on wireless communication signal |
-
2023
- 2023-02-17 CN CN202310128128.5A patent/CN116095828B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100135178A1 (en) * | 2008-11-21 | 2010-06-03 | Qualcomm Incorporated | Wireless position determination using adjusted round trip time measurements |
| US20140187257A1 (en) * | 2013-01-03 | 2014-07-03 | Qualcomm Incorporated | Inter-ap distance estimation using crowd sourcing |
| US20150146553A1 (en) * | 2013-01-29 | 2015-05-28 | Qualcomm Incorporated | System and method for deploying an rtt-based indoor positioning system |
| US20150131460A1 (en) * | 2013-11-13 | 2015-05-14 | Qualcomm Incorporated | Method and apparatus for using rssi and rtt information for choosing access points to associate with |
| US20180252795A1 (en) * | 2017-03-03 | 2018-09-06 | Qualcomm Incorporated | Enhancing indoor positioning using passive acoustic tags |
| KR20220047491A (en) * | 2020-10-09 | 2022-04-18 | 주식회사 와따 | Indoor location idendifying system |
| KR20220077542A (en) * | 2020-12-02 | 2022-06-09 | 주식회사 와따 | Indoor location idendifying system based on wireless communication signal |
Non-Patent Citations (1)
| Title |
|---|
| 徐捷;周言;吴哲夫;: "基于信道状态的室内定位技术研究", 电声技术, no. 10 * |
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