An asynchronous fusion positioning method based on departure angle and RSSI value

Abstract

The invention discloses an asynchronous fusion positioning method based on departure angle and RSSI value, comprising: a base station periodically broadcasts a radio signal containing a base station MAC address; a terminal receives the base station broadcast signal for receiving time mark, and at the same time, extracts information such as the base station MAC address, departure angle, and RSSI value, and groups the received data according to the base station MAC address; within a time interval T, the data within each group of data time period NT is taken as a group, clustered according to the RSSI value and abnormal data is excluded, and each group of clustered data is recombined for fusion positioning; preliminary positioning is performed by using the pole method according to information such as the base station position coordinates and the terminal working height, and the fuzzy positioning area is expanded to the surroundings to form a fuzzy positioning area, and then the fuzzy positioning area weight is designed according to the arrival angle and RSSI value, the overlapping area weights are superimposed, and the center of gravity of the area with the largest weight is used as the fusion positioning estimation value of the terminal; finally, the fusion positioning estimation value is subjected to Kalman filtering at the time interval T to obtain a stable fusion result.

Description

Technical Field

[0001] The invention relates to the technical field of radio signal direction finding, and in particular to an asynchronous fusion positioning method based on a departure angle and an RSSI value. Background Art

[0002] With the development of wireless communication technology and the popularization of mobile intelligent terminals, indoor positioning has become a hot application in the current information industry and presents a broad market prospect. The system based on multi-station radio direction finding positioning has high positioning accuracy, but it is affected by multipath, interference, occlusion, etc., and the positioning stability faces great challenges. The present invention groups the observation data such as the departure angle and RSSI value observed by the terminal according to the MAC address of the base station and sorts them according to the receiving time. Within the time interval T, the data in each group of data NT time period is regarded as a group, clustered according to the RSSI value and abnormal data is excluded, and the base station position coordinates, the terminal working height and other information are used to perform preliminary positioning through the pole method and expand to the surroundings to form a fuzzy positioning area, and then the fuzzy positioning area weight is designed according to the arrival angle and RSSI value, the overlapping area weights are superimposed, and the center of gravity of the area with the largest weight is used as the fusion positioning estimate of the terminal. Finally, the fusion positioning estimate is subjected to Kalman filtering at the time interval T to obtain a stable fusion result. The present invention enables the terminal to obtain a stable and accurate estimate of its own position, and has the characteristics of asynchronous fusion and high positioning accuracy. Summary of the invention

[0003] In order to overcome the deficiencies in the prior art, the present invention provides an asynchronous fusion positioning method based on departure angle and RSSI value, which can enable a terminal to obtain a stable and accurate estimate of its own position and has the characteristics of asynchronous fusion and high positioning accuracy.

[0004] In order to achieve the above-mentioned invention object, the technical solution adopted to solve the technical problem is as follows:

[0005] An asynchronous fusion positioning method based on departure angle and RSSI value comprises the following steps:

[0006] Step S1: The base station will periodically broadcast a radio signal containing the base station MAC address;

[0007] Step S2: The terminal receives the base station broadcast signal and marks the reception time. At the same time, it extracts the base station MAC address, departure angle, and RSSI value information, groups the received data according to the base station MAC address, and sorts each group of data according to the reception time;

[0008] Step S3: within the time interval T, the data in each group of data within the time period NT is taken as a group, clustered according to the RSSI value and the abnormal data is excluded, and the clustered data of each group is recombined for fusion positioning;

[0009] Step S4: Preliminary positioning is performed using the pole method based on the base station location coordinates and the terminal working height information, and then expanded to form a fuzzy positioning area in all directions. The fuzzy positioning area weight is then designed based on the arrival angle and RSSI value. The overlapping area weights are superimposed, and the center of gravity of the area with the largest weight is used as the fusion positioning estimate of the terminal.

[0010] Step S5: The fused positioning estimate is subjected to Kalman filtering at time interval T to obtain a stable fusion result.

[0011] Furthermore, the step S1 includes the following steps:

[0012] The radio signal broadcast by the base station contains the MAC address used by the terminal to distinguish the base station and the base station location information.

[0013] Furthermore, the step S2 includes the following steps:

[0014] Step S21: The terminal receives the base station broadcast signal and performs reception time stamping;

[0015] Step S22: The terminal extracts the base station MAC address, departure angle, and RSSI value information;

[0016] Step S23: The terminal groups the received data according to the MAC address of the base station, and all the data in each group corresponds to all the information observed by the terminal on a base station;

[0017] Step S24: sorting each group of data according to the time of receipt.

[0018] Furthermore, the step S3 includes the following steps:

[0019] Step S31: for each type of data within the time interval T, each group of data within the forward NT time period is regarded as a group. The smaller N is, the stronger the real-time performance is and the greater the jitter is. On the contrary, the larger N is, the weaker the real-time performance is and the smaller the jitter is.

[0020] Step S32: Each group calculates the distance between two RSSI values, sets a distance threshold, clusters the data that is smaller than the threshold, and excludes the data that is larger than the threshold;

[0021] Step S33: Recombining the clustered data of each group for fusion positioning.

[0022] Furthermore, the step S4 includes the following steps:

[0023] Step S41: Preliminary positioning using the pole method based on the base station location coordinates and the terminal working height information;

[0024] Step S42: Taking the preliminary positioning position as the center, the pitch angle and the azimuth angle are expanded to the surrounding area according to the direction finding accuracy of the direction finding algorithm to form a fuzzy positioning area. The real position is likely to fall within the fuzzy positioning area.

[0025] Step S43: designing the fuzzy positioning area weight according to the pitch angle and the RSSI value. The larger the pitch angle, the stronger the energy, and the larger the weight value. On the contrary, the smaller the pitch angle, the weaker the energy, and the smaller the weight value.

[0026] Step S44: The weights of the overlapping areas are superimposed to find the area with the largest weight, and the center of gravity position of the area is used as the fusion positioning estimation value of the terminal.

[0027] Furthermore, the step S5 includes the following steps:

[0028] Step S51: smoothing the fused positioning estimate value by Kalman filtering;

[0029] Step S52: design the access conditions for the terminal to enter the system working area in combination with the coverage range, pitch angle and RSSI value of the positioning system. When the observation data meets the access conditions, it is considered that the terminal has entered the system working range, and the starting state of the Kalman filter is set according to the latest fusion positioning estimation value;

[0030] Step S53: design the leaving condition of the terminal leaving the system working area in combination with the coverage range, pitch angle, RSSI value and receiving time stamp of the positioning system. When the observed data or the receiving time stamp meets the leaving condition, it is considered that the terminal leaves the system working range and the Kalman filter is stopped.

[0031] Step S54: Perform Kalman filtering on the fused positioning estimate within the system coverage area.

[0032] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art:

[0033] The invention discloses an asynchronous fusion positioning method based on departure angle and RSSI value, which can enable a terminal to obtain a stable and accurate estimation value of its own position and has the characteristics of asynchronous fusion and high positioning accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0035] Figure 1It is a flow chart of an asynchronous fusion positioning method based on departure angle and RSSI value of the present invention;

[0036] Figure 2 It is a schematic diagram of a positioning system corresponding to an asynchronous fusion positioning method based on departure angle and RSSI value of the present invention. DETAILED DESCRIPTION

[0037] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] This embodiment discloses an asynchronous fusion positioning method based on departure angle and RSSI value. The process is as follows: Figure 1 As shown, the corresponding positioning system is as Figure 2 As shown, the specific steps include:

[0039] Step S1: The base station will periodically broadcast a radio signal containing the base station MAC address;

[0040] Step S2: The terminal receives the base station broadcast signal and marks the reception time. At the same time, it extracts the base station MAC address, departure angle, RSSI value and other information, groups the received data according to the base station MAC address, and sorts each group of data according to the reception time;

[0041] Step S3: within the time interval T, the data in each group of data within the time period NT is taken as a group, clustered according to the RSSI value and the abnormal data is excluded, and the clustered data of each group is recombined for fusion positioning;

[0042] Step S4: Preliminary positioning is performed using the pole method based on the base station location coordinates, the terminal working height and other information, and then expanded to form a fuzzy positioning area in all directions. The fuzzy positioning area weight is then designed based on the arrival angle and RSSI value. The overlapping area weights are superimposed, and the center of gravity of the area with the largest weight is used as the fusion positioning estimate of the terminal.

[0043] Step S5: The fused positioning estimate is subjected to Kalman filtering at time interval T to obtain a stable fusion result.

[0044] Furthermore, the step S1 includes the following steps:

[0045] The radio signal broadcast by the base station contains the MAC address used by the terminal to distinguish the base station and the base station location information.

[0046] Furthermore, the step S2 includes the following steps:

[0047] Step S21: The terminal receives the base station broadcast signal and performs reception time stamping;

[0048] Step S22: The terminal extracts information such as the base station MAC address, departure angle, and RSSI value;

[0049] Step S23: The terminal groups the received data according to the MAC address of the base station, and all the data in each group corresponds to all the information observed by the terminal on a base station;

[0050] Step S24: sorting each group of data according to the time of receipt.

[0051] Furthermore, the step S3 includes the following steps:

[0052] Step S31: for each type of data within a time interval T (such as 0.1s), each group of data within a forward NT (such as 1s) time period is regarded as a group;

[0053] Step S32: Each group calculates the distance between two RSSI values, sets a distance threshold, clusters the data that is smaller than the threshold, and excludes the data that is larger than the threshold;

[0054] Step S33: Recombining the clustered data of each group for fusion positioning.

[0055] Furthermore, the step S4 includes the following steps:

[0056] Step S41: Preliminary positioning using the pole method based on the base station location coordinates, terminal working height and other information;

[0057] Step S42: Taking the preliminary positioning position as the center, the pitch angle and the azimuth angle are expanded to the surrounding area according to the direction finding accuracy of the direction finding algorithm to form a fuzzy positioning area. The real position is likely to fall within the fuzzy positioning area.

[0058] Step S43: designing the fuzzy positioning area weight according to the pitch angle and the RSSI value. The larger the pitch angle, the stronger the energy, and the larger the weight value. On the contrary, the smaller the pitch angle, the weaker the energy, and the smaller the weight value.

[0059] Step S44: The weights of the overlapping areas are superimposed to find the area with the largest weight, and the center of gravity position of the area is used as the fusion positioning estimation value of the terminal.

[0060] Furthermore, the step S5 includes the following steps:

[0061] Step S51: smoothing the fused positioning estimate value by Kalman filtering;

[0062] Step S52: design the access conditions for the terminal to enter the system working area in combination with the coverage range, pitch angle and RSSI value of the positioning system. When the observation data meets the access conditions, it is considered that the terminal has entered the system working range, and the starting state of the Kalman filter is set according to the latest fusion positioning estimation value;

[0063] Step S53: design the leaving condition of the terminal leaving the system working area in combination with the coverage range, pitch angle, RSSI value and receiving time stamp of the positioning system. When the observed data or the receiving time stamp meets the leaving condition, it is considered that the terminal leaves the system working range and the Kalman filter is stopped.

[0064] Step S54: Perform Kalman filtering on the fused positioning estimate within the system coverage area.

[0065] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An asynchronous fusion positioning method based on departure angle and RSSI value, characterized in that: The following steps are involved: Step S1: The base station will periodically broadcast a radio signal containing the base station MAC address; Step S2: The terminal receives the base station broadcast signal and marks the reception time. At the same time, it extracts the base station MAC address, departure angle, and RSSI value information, groups the received data according to the base station MAC address, and sorts each group of data according to the reception time; Step S3: Within the time interval T, the data within the time period NT of each group of data is taken as a group, clustered according to the RSSI value and the abnormal data is excluded, and the clustered data of each group is recombined for fusion positioning; Step S4: Preliminary positioning is performed using the pole method based on the base station location coordinates and the terminal working height information, and then expanded to form a fuzzy positioning area in all directions. The fuzzy positioning area weight is then designed based on the departure angle and RSSI value. The overlapping area weights are superimposed, and the center of gravity of the area with the largest weight is used as the terminal's fusion positioning estimate. The step S4 includes the following steps: Step S41: Preliminary positioning using the pole method based on the base station location coordinates and the terminal working height information; Step S42: Taking the preliminary positioning position as the center, the pitch angle and the azimuth angle are expanded to the surrounding area according to the direction finding accuracy of the direction finding algorithm to form a fuzzy positioning area. The real position is likely to fall within the fuzzy positioning area. Step S43: designing the fuzzy positioning area weight according to the pitch angle and the RSSI value. The larger the pitch angle, the stronger the energy, and the larger the weight value. On the contrary, the smaller the pitch angle, the weaker the energy, and the smaller the weight value. Step S44: The weights of the overlapping areas are superimposed to find the area with the largest weight, and the center of gravity position of the area is used as the fusion positioning estimation value of the terminal; Step S5: The fused positioning estimate is subjected to Kalman filtering at time interval T to obtain a stable fusion result.

2. The asynchronous fusion positioning method based on departure angle and RSSI value according to claim 1, characterized in that: The step S1 includes the following steps: The radio signal broadcast by the base station contains the MAC address used by the terminal to distinguish the base station and the base station location information.

3. The asynchronous fusion positioning method based on departure angle and RSSI value according to claim 1, characterized in that: The step S2 includes the following steps: Step S21: The terminal receives the base station broadcast signal and performs reception time stamping; Step S22: The terminal extracts the base station MAC address, departure angle, and RSSI value information; Step S23: The terminal groups the received data according to the MAC address of the base station, and all the data in each group corresponds to all the information observed by the terminal on a base station; Step S24: sorting each group of data according to the time of receipt.

4. The asynchronous fusion positioning method based on departure angle and RSSI value according to claim 1, characterized in that: The step S3 includes the following steps: Step S31: for each type of data within the time interval T, each group of data within the forward NT time period is regarded as a group. The smaller N is, the stronger the real-time performance is and the greater the jitter is. On the contrary, the larger N is, the weaker the real-time performance is and the smaller the jitter is. Step S32: Each group calculates the distance between two RSSI values, sets a distance threshold, clusters the data that is smaller than the threshold, and excludes the data that is larger than the threshold; Step S33: Recombining the clustered data of each group for fusion positioning.

5. The asynchronous fusion positioning method based on departure angle and RSSI value according to claim 1, characterized in that: The step S5 includes the following steps: Step S51: smoothing the fused positioning estimate value by Kalman filtering; Step S52: design the access conditions for the terminal to enter the system working area in combination with the coverage range, pitch angle and RSSI value of the positioning system. When the observation data meets the access conditions, it is considered that the terminal has entered the system working range, and the starting state of the Kalman filter is set according to the latest fusion positioning estimation value; Step S53: design the leaving condition of the terminal leaving the system working area in combination with the coverage range, pitch angle, RSSI value and receiving time stamp of the positioning system. When the observed data or the receiving time stamp meets the leaving condition, it is considered that the terminal leaves the system working range and the Kalman filter is stopped. Step S54: Perform Kalman filtering on the fused positioning estimate within the system coverage area.

Images