Composite positioning method and system based on GPS, WiFi and LBS

Abstract

The invention discloses a composite positioning method and system based on GPS, WiFi and LBS, and belongs to the technical field of positioning. The system comprises a GPS positioning module, a WiFi positioning module, an LBS positioning module, a G-sensor module, an equipment coordinate initialization module, a positioning result determination module, a monitoring module and a storage module. According to the invention, the coordinate position of the device is positioned through the GPS positioning module, the WiFi positioning module and the LBS positioning module, the movement of the device is monitored through the G-sensor module, the sleep and wake-up of the positioning module are controlled, and the positioning result is corrected, so that the positioning stability and accuracy are improved, the power consumption of the device is reduced, and the problem of positioning drift is solved to a certain extent.

Description

Technical Field

[0001] The present application relates to the field of positioning technology, and more specifically to a composite positioning method and system based on GPS, WiFi and LBS. Background Art

[0002] With the development of today's society, people are using more and more positioning needs. In addition to GPS positioning, the demand for positioning technologies based on Bluetooth, WiFi, LBS, UWB, RFID, etc. is also increasing. Various positioning technologies have their own applicable places. GPS positioning has high accuracy, but the positioning effect is not good in scenes such as inside buildings, tunnels, and underground spaces; LBS positioning accuracy depends on the coverage range and number of base stations, and usually there is an error of 50-3000 meters; WiFi positioning depends on the database of the correspondence between the MAC address of the wireless access point AP and the geographical location and the density of the access point AP that can be used for positioning. At the same time, signal interference will also affect the accuracy of WiFi positioning, and usually there is an error of 10-100 meters; UWB, RFID, Bluetooth and other positioning technologies require additional equipment deployment and have poor applicability.

[0003] At present, most smart devices integrate GPS, WiFi and mobile network modules, and can perform GPS, WiFi and LBS positioning. With the help of existing positioning technologies, integrated indoor and outdoor positioning can be basically achieved. However, the switching of existing positioning methods is usually based on the recognition of the environment in which the smart device is located, which requires additional sensors and other equipment or special scenarios, is not universal, and depends on the accuracy of indoor and outdoor environment recognition. When the environment recognition is wrong, the selection of the positioning method is wrong, resulting in poor positioning effect or positioning failure. In addition, GPS, WiFi, and LBS positioning are always in working state, which will also cause increased power consumption and waste of resources. Summary of the invention

[0004] Therefore, this application is proposed to address the problems and needs existing in the above-mentioned prior art.

[0005] The purpose of this application is to provide a composite positioning method and system based on GPS, WiFi and LBS, which, compared with the defects of the prior art, can improve the stability and accuracy of positioning without the need for additional equipment or in special scenarios, while reducing the power consumption of the equipment to achieve power saving, and can also solve the positioning drift problem to a certain extent.

[0006] The purpose of this application is achieved through the following technical solutions: In a first aspect, the present application provides a composite positioning method based on GPS, WiFi and LBS, the method comprising: S1, obtaining a WiFi positioning result according to the access point AP information of the nearby wireless local area network WLAN obtained within a first time interval, and obtaining a LBS positioning result according to the nearby base station information obtained within a second time interval; S2, obtaining ephemeris data related to the WiFi positioning or LBS positioning result, and accelerating GPS positioning through the ephemeris data; initializing the coordinate position according to the GPS, WiFi, LBS positioning results and preset coordinates, and the GPS, WiFi, LBS positioning functions enter a dormant state; S3, monitoring the movement of the device according to the G-sensor, if the movement time of the device is monitored to exceed the third time interval threshold, waking up the GPS positioning, monitoring the positioning result of the GPS positioning within the fourth time interval threshold, if the GPS positioning is successful, outputting the positioning result, otherwise waking up the WiFi positioning; S4, monitoring the positioning result within the fifth time interval threshold after WiFi positioning is awakened, and outputting the positioning result if WiFi positioning is successful, otherwise waking up LBS positioning; monitoring the positioning result within the sixth time interval threshold after LBS positioning is awakened, and outputting the positioning result if successful, otherwise estimating the coordinate position according to the last stored positioning result and the movement distance estimated by the G-sensor; S5. Monitor the movement of the device after being awakened by GPS positioning. If the device does not move within the seventh time interval threshold, GPS, WiFi, and LBS positioning enter a dormant state; and repeat S4 to monitor the movement of the device.

[0007] In a second aspect, the present application provides a composite positioning system based on GPS, WiFi and LBS, the system comprising the following modules: GPS positioning module, used to implement A-GPS positioning function and obtain GPS positioning results; The WiFi positioning module is used to implement the WiFi positioning function according to the WiFi RSSI value and obtain the WiFi positioning result. It includes the following units: WiFiSCAN unit, used to scan and obtain the wireless access point AP information of the wireless local area network WLAN near the device; A WiFi screening unit is used to screen the AP data obtained by the WiFiSCAN unit to screen out wireless access points AP that can be used for WiFi positioning; An AP position determination unit, used to determine a coordinate position of an access point AP that can be used for positioning; A WiFi abnormal signal filtering unit is used to remove abnormal data from RSSI data in available access point AP data using an improved recursive average filtering algorithm; A WiFi positioning unit is used to obtain WiFi positioning results according to the location of an available access point AP, RSSI data filtered by the available access point AP, and a Rayleigh fading channel model; The LBS positioning module is used to implement the LBS positioning function according to the RSSI value of the base station and obtain the LBS positioning result. It includes the following units: A base station acquisition unit is used to obtain base station information near the device, including base station LAC, CELLID and RSSI values; A base station location determination unit, used to obtain the coordinate position of the base station according to the base station LAC and CELLID; An RSSI abnormal signal elimination unit is used to eliminate abnormal data using an improved recursive average filtering algorithm for RSSI data in base station information; The base station positioning unit is used to obtain the LBS positioning result according to the latitude and longitude coordinates of the base station, the RSSI data filtered by the base station and the Rayleigh fading channel model; G-sensor module, used to wake up the device and monitor its movement, and obtain its movement direction and acceleration; The device coordinate initialization module is used to initialize the device coordinate position according to the GPS, WiFi, LBS positioning results and preset coordinates; The positioning result determination module is used to determine the location of the device based on the stored last positioning coordinates, the movement distance estimated by the G-sensor, and the GPS, WiFi, and LBS positioning results; The monitoring module is used to monitor the continuous motion time of the device, monitor the positioning results and module wake-up of GPS, WiFi, and LBS positioning within the preset time, and sleep the GPS, WiFi, and LBS positioning functions when the device does not move within the preset time; The storage module is used to store the coordinate position of the device, the acquired AP information and base station information, and the calculation result information.

[0008] Compared with the prior art, the beneficial effects of the present invention are at least as follows: The composite positioning method and system based on GPS, WiFi and LBS of the present application use an improved recursive average filtering algorithm to filter abnormal data from RSSI data in collected WiFi or base station information, reduce the influence of noise on positioning results, improve positioning accuracy, and obtain ephemeris data through the results of WiFi or base station positioning to accelerate the GPS positioning process; monitor the movement of the device through the G-sensor to determine the sleep and wake-up of the GPS, WiFi and LBS positioning functions, thereby reducing the power consumption of the device to achieve the purpose of power saving; improve the stability of positioning through the mutual cooperation of GPS, WiFi and LBS positioning; for the case of a single base station or a single available access point AP, the positioning result is corrected based on the last positioning result and the moving distance estimated by the G-sensor, thereby improving the positioning accuracy and solving the positioning drift problem to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 The figure shows a method flow chart of a composite positioning method based on GPS, WiFi and LBS provided according to an embodiment of the present application; Figure 2 The figure shows a flow chart of a method for obtaining WiFi positioning results according to access point AP information provided in an embodiment of the present application; Figure 3 The figure shows a flow chart of a method for removing abnormal data using an improved recursive average filtering algorithm for RSSI data in available access point AP data according to an embodiment of the present application; Figure 4 The figure shows a flow chart of a method for obtaining LBS positioning results according to an embodiment of the present application; Figure 5 The figure shows a schematic diagram of a composite positioning system based on GPS, WiFi and LBS provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0010] Below, the exemplary embodiments according to the present application will be described in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described here are only part of the embodiments of the present application, and the present application is not limited to the exemplary embodiments described here.

[0011] Please refer to Figure 1 , which shows a method flow chart of a composite positioning method based on GPS, WiFi and LBS provided according to an embodiment of the present application. The composite positioning method based on GPS, WiFi and LBS includes: S1, obtaining a WiFi positioning result according to the access point AP information of the nearby wireless local area network WLAN obtained within a first time interval, and obtaining a LBS positioning result according to the nearby base station information obtained within a second time interval; The composite positioning method and system based on GPS, WiFi and LBS provided in the embodiment of the present application are applied to a communication device, which is provided with a SIM card and a gravity acceleration sensor G-sensor, and has a WiFiSCAN function; after the device is powered on, the system completes the initialization, and obtains the access point AP information of the wireless local area network WLAN near the device through the WiFiSCAN function, wherein the access point AP information includes MAC (Media Access Control Address) and RSSI (Received Signal Strength Indication), and the scanning time can be set to a predetermined time range, for example, it can be a continuous scan within 10 to 15 seconds, and after each successful scan, the access point AP information is stored in an array, the data in the array is in the form of a dictionary, with the MAC address of the access point AP as the key and the array storing the RSSI as the value, and after the predetermined scanning time, the array storing the access point AP information is sent to the server for processing; the information of the nearby base stations connected to is obtained through the SIM card, and the base station information includes LAC (Location Area Code, location area code), CELLID (CELLIdentification, cellular cell ID) and RSSI. The scanning time can also be a preset time, such as 5-10 seconds of continuous scanning. After each successful scan, the data is also stored in an array. The data format in the array is a dictionary with CELLID as the key and the array storing LAC and RSSI as the value. After the preset scanning time, the array storing the base station information is sent to the server for processing; After receiving the array of AP information of wireless local area network WLAN sent by the device, the server processes the data to obtain the first WiFi positioning result. For the specific process, please refer to Figure 2 As shown, the specific steps include: S11, filtering unavailable access point AP data; There are access points with uncertain geographical locations in the access point AP array obtained by the device scan. This part of the access point data cannot be used for positioning the device because of the unknown location. Therefore, it is necessary to filter out the available access point AP data that can be used for WiFi positioning from the obtained access point AP array. The server filters out the array of access point APs that can be used for positioning from the access point AP array obtained by scanning according to the database of access point APs with determined geographical locations stored; S12, using an improved recursive average filtering algorithm to remove abnormal data from RSSI data in the available access point AP data; In the array of access points AP that can be used for positioning after screening, the RSSI value corresponding to each access point AP is an array. Since the signal is affected by interference and other external factors, abnormal data will appear, so it is necessary to eliminate the influence of these abnormal data; the recursive average filtering algorithm can be used to filter out noise and abnormal values ​​in the RSSI signal and reduce positioning errors. If only the conventional recursive average filtering algorithm is used, it cannot guarantee that abnormal data will be completely eliminated. Therefore, it is proposed to use an improved recursive average filtering algorithm to eliminate RSSI abnormal data. The specific steps are as shown in reference Figure 3 As shown, including: S121, select an available access point AP, and arrange N RSSI data of the available access point AP in ascending order, A1, A2, A3, ...A N ; The available access point AP array may include data of multiple access points AP, so it is necessary to process them one by one, select an access point AP in the available access point AP array, and arrange the N RSSI data in the RSSI array of the available access point AP in ascending order to obtain ascending data A1, A2, A3, ...A N ; S122, filter out A1, A2, ...A from the above sequence M , a total of M minimum values, and A N-M+1 , A N-M+2 , ...A N , a total of M maximum values; Filter the data in ascending order, remove the M smallest values ​​from the head of the queue, and remove the M largest values ​​from the tail of the queue to obtain the final N-2M RSSI data. The value of M can be adjusted according to the length of N and is proportional to the length of N. S123, calculate the average value of the remaining N-2M RSSI data, as shown in formula (1) = (1); S124, repeat the above steps until the abnormal RSSI data of all available access points AP are eliminated; In the case where there are multiple access points AP in the available access point AP array, the above processing steps are repeated until the RSSI data of all access points AP in the array are subjected to abnormal data elimination; Return to reference Figure 2 , in step S13, obtaining a WiFi positioning result according to the position of the available access point AP, the RSSI data filtered by the available access point AP, and the Rayleigh fading channel model; According to the MAC address of the available access point AP, the location coordinates of the access point AP are found from the data stored in the server. The WiFi signal strength fading curve is constructed by the Rayleigh fading channel model. The KNN algorithm is used to find K neighboring points based on the RSSI fading curve and the RSSI value after filtering of the available access point AP. If there is more than one available access point AP, the final neighboring point can be determined as the device location based on the neighboring points determined by multiple access points AP, and then the coordinates of the device are calculated based on the coordinates of one or more access points AP and the determined neighboring points; Return to reference Figure 1 In step S1, after receiving the array containing base station information sent by the device, the server processes the data to obtain the first LBS positioning result. For the specific process, please refer to Figure 4 As shown, the following steps are included: S14, using an improved recursive average filtering algorithm to remove abnormal data from the RSSI data in the base station information; The RSSI data in the acquired base station information contains abnormal data due to the influence of the propagation process. Therefore, the RSSI data also needs to be processed as in WiFi positioning. The processing process is similar to that of WiFi positioning. For the array that stores the acquired base station information, base stations are selected one by one and the improved recursive average filtering algorithm is used to eliminate the abnormal data in the RSSI data, and finally the RSSI value with high credibility corresponding to the base station is obtained; S15, obtaining the latitude and longitude coordinates of the base station according to the base station LAC and CELLID; The server queries the location of the base station through the LAC and CELLID of the base station and obtains the longitude and latitude coordinates corresponding to the base station. If there are multiple base station information, the corresponding coordinate positions of multiple base stations can be obtained; S16, obtaining LBS positioning results according to the latitude and longitude coordinates of the base station, RSSI data after base station filtering, and Rayleigh fading channel model; The RSSI signal strength fading curve of the base station is constructed according to the Rayleigh fading channel model. The KNN algorithm is used to find K nearest neighbor points based on the RSSI fading curve and the RSSI value after filtering by the base station. If there is more than one base station, the final nearest neighbor point can be determined as the device location based on the nearest neighbor points determined by multiple base stations, and then the coordinates of the device are calculated based on the coordinates of one or more base stations and the determined nearest neighbor points. Return to reference Figure 1 In step S2, the ephemeris data related to the WiFi positioning or LBS positioning result is obtained, and the GPS positioning is accelerated by the ephemeris data; the coordinate position is initialized according to the GPS, WiFi, LBS positioning results and the preset coordinates, and the GPS, WiFi, LBS positioning functions enter a dormant state; Since the first GPS positioning requires searching for stars, it takes a long time to locate the location. At this time, A-GPS auxiliary positioning is needed to speed up the positioning process. WiFi or LBS positioning is faster. You can download data such as ephemeris based on the coarse-precision coordinates obtained by WiFi or LBS positioning, and then load the ephemeris data into the GPS positioning chip to realize the A-GPS function and speed up the GPS positioning process. When GPS positioning fails, it will repeat N attempts. If N positioning attempts fail, it is determined that the current GPS cannot locate. Due to the relationship between the accuracy of GPS positioning, WiFi positioning, and LBS positioning, the credibility of the three positioning methods when they are successfully positioned is ranked, among which GPS priority>WiFi priority>LBS priority, that is, first take the coordinates of the successful GPS positioning to initialize the coordinates of the device, if GPS positioning fails, take the coordinates of the successful WiFi positioning to initialize the coordinates of the device, if WiFi positioning fails, take the coordinates of the successful LBS positioning to initialize the coordinates of the device; if all three positioning methods are unsuccessful, initialize the coordinate position of the device according to the preset fixed coordinate position of the device; at this time, the GPS, WiFi, and LBS positioning functions can be put into sleep mode to reduce the power consumption of the device; S3, monitoring the movement of the device according to the G-sensor, if the movement time of the device is monitored to exceed the third time interval threshold, waking up the GPS positioning, monitoring the positioning result of the GPS positioning within the fourth time interval threshold, if the GPS positioning is successful, outputting the positioning result, otherwise waking up the WiFi positioning; According to the motion state of the device monitored by the G-sensor, if the G-sensor detects that the device is in motion and the motion time exceeds the third time interval threshold, the GPS positioning function of the device is awakened to perform a positioning operation to determine the location of the device at this time. For example, the third time interval threshold may be 5-10 seconds, which is not specifically limited here; after waking up the GPS positioning, the positioning result of the GPS positioning within the fourth time interval threshold is monitored. If the GPS positioning is successful within the fourth time interval threshold, the device location at this time is set according to the GPS positioning result. If the GPS positioning fails, the WiFi positioning function is awakened to determine the location of the device at this time. The fourth time interval threshold may be 2-5 seconds, which is not limited here; S4, monitoring the positioning result within the fifth time interval threshold after WiFi positioning is awakened, and outputting the positioning result if WiFi positioning is successful, otherwise waking up LBS positioning; monitoring the positioning result within the sixth time interval threshold after LBS positioning is awakened, and outputting the positioning result if successful, otherwise estimating the coordinate position according to the last stored positioning result and the movement distance estimated by the G-sensor; After waking up the WiFi positioning function, enable the WiFiSCAN function to scan nearby wireless access points within a predetermined time. Use the above references based on the wireless access point information obtained by scanning. Figure 2 The steps S11-S13 in the above step are used to perform WiFi positioning, and the positioning results of WiFi positioning within the fifth time interval threshold are monitored. If the WiFi positioning is successful, the coordinates of the WiFi positioning are used as the coordinate position of the device at this time, otherwise the LBS positioning function is awakened to determine the position of the device; wherein the fifth time interval threshold may be 2-3 seconds, which is not limited here; preferably, if the wireless access point AP obtained at this time has not changed and the RSSI value after processing has not changed significantly, the result of the last WiFi positioning is used as the current positioning result; preferably, if there is only one wireless access point AP obtained at this time, since it can only be determined that the device is in a certain signal attenuation band of the wireless access point AP, the WiFi positioning result can be corrected according to the coordinates of the last successful positioning and the moving distance estimated based on the G-sensor, and the final coordinates of the device can be determined; WiFi positioning fails to wake up the LBS positioning function for the final positioning attempt. The LBS positioning process is the same as the above reference Figure 4 The steps S14-S16 shown are the same, monitoring the positioning results of LBS positioning within the sixth time interval threshold, the sixth time interval threshold can be 2-3 seconds, the process of scanning the base station signal can last about 1 second, if the base station positioning is successful within the predetermined time, the base station positioning result at this time is used as the coordinates of the device at this time, if the base station positioning is also unsuccessful, the coordinate position of the device is determined according to the last positioning result stored in the system and the movement distance estimated by the G-sensor and the measured acceleration direction; if there is only one base station information obtained during the base station positioning this time, the base station positioning result is corrected in the same way as the steps for the above-mentioned single access point AP positioning; due to the need to continuously obtain the device position change to draw the trajectory point, the total duration of GPS, WiFi, and LBS positioning should be less than the duration of the device movement monitored when responding to the positioning wake-up, that is, the third time interval threshold> (fourth time interval threshold+fifth time interval threshold+sixth time interval threshold); S5. Monitor the movement of the device after being awakened by GPS positioning. If the device does not move within the seventh time interval threshold, GPS, WiFi, and LBS positioning enter a dormant state; and repeat S3 to monitor the movement of the device.

[0012] After the GPS positioning function is awakened, the movement of the device is continuously monitored according to the G-sensor. If the movement of the device is detected and exceeds the third time interval threshold, the positioning operation is continued to determine the device position. If the movement of the device is not detected within the seventh time interval threshold after the positioning function is awakened, the GPS, WiFi, and LBS positioning functions are put into a dormant state to reduce the power consumption of the device. At this time, the movement state of the device is still monitored according to the G-sensor to realize the awakening positioning function. In order to avoid frequent dormancy and awakening of the positioning module, the seventh time interval threshold should be much larger than the third time interval threshold.

[0013] Below, reference Figure 5 A composite positioning system based on GPS, WiFi and LBS according to an embodiment of the present application is described below. Figure 5 As shown, the composite positioning system based on GPS, WiFi and LBS includes: GPS positioning module, used to implement A-GPS positioning function and obtain GPS positioning results; The GPS positioning module receives the ephemeris data downloaded according to the positioning results of the WiFi or LBS positioning module to implement the A-GPS positioning function, obtain the positioning results, and implement sleep and wake-up according to the G-sensor module and the monitoring module to achieve the purpose of reducing power consumption; The WiFi positioning module is used to implement the WiFi positioning function according to the WiFi RSSI value and obtain the WiFi positioning result. It includes the following units: WiFiSCAN unit, used to scan and obtain the wireless access point AP information of the wireless local area network WLAN near the device; A WiFi screening unit is used to screen the AP data obtained by the WiFiSCAN unit to screen out wireless access points AP that can be used for WiFi positioning; An AP position determination unit, used to determine a coordinate position of an access point AP that can be used for positioning; A WiFi abnormal signal filtering unit is used to remove abnormal data from RSSI data in available access point AP data using an improved recursive average filtering algorithm; A WiFi positioning unit is used to obtain WiFi positioning results according to the location of an available access point AP, RSSI data filtered by the available access point AP, and a Rayleigh fading channel model; The LBS positioning module is used to implement the LBS positioning function according to the RSSI value of the base station and obtain the LBS positioning result. It includes the following units: A base station acquisition unit is used to obtain base station information near the device, including base station LAC, CELLID and RSSI values; A base station location determination unit, used to obtain the coordinate position of the base station according to the base station LAC and CELLID; An RSSI abnormal signal elimination unit is used to eliminate abnormal data using an improved recursive average filtering algorithm for RSSI data in base station information; The base station positioning unit is used to obtain the LBS positioning result according to the latitude and longitude coordinates of the base station, the RSSI data filtered by the base station and the Rayleigh fading channel model; G-sensor module, used to wake up the device and monitor its movement, and obtain its movement direction and acceleration; The device coordinate initialization module is used to initialize the device coordinate position according to the GPS, WiFi, LBS positioning results and preset coordinates; The positioning result determination module is used to determine the location of the device based on the stored last positioning coordinates, the movement distance estimated by the G-sensor, and the GPS, WiFi, and LBS positioning results; The monitoring module is used to monitor the continuous motion time of the device, monitor the positioning results and module wake-up of GPS, WiFi, and LBS positioning within the preset time, and sleep the GPS, WiFi, and LBS positioning functions when the device does not move within the preset time; The storage module is used to store the coordinate position of the device, the acquired AP information and base station information, and the calculation result information.

[0014] The specific functions and operations of each module and each unit in the above-mentioned composite positioning system based on GPS, WiFi and LBS are described in detail in the composite positioning method based on GPS, WiFi and LBS described above, so their repeated description will be omitted here.

[0015] The basic principles of the present application are described above in conjunction with specific embodiments. It should be understood that the specific details disclosed above are only for illustration and ease of understanding, and are not restrictive, and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A composite positioning method based on GPS, WiFi and LBS, characterized in that: The method comprises: S1, obtaining a WiFi positioning result according to the access point AP information of the nearby wireless local area network WLAN obtained within a first time interval, and obtaining a LBS positioning result according to the nearby base station information obtained within a second time interval; S2, obtaining ephemeris data related to the WiFi positioning or LBS positioning result, and accelerating GPS positioning through the ephemeris data; initializing the coordinate position according to the GPS, WiFi, LBS positioning results and preset coordinates, and the GPS, WiFi, LBS positioning functions enter a dormant state; S3, monitoring the movement of the device according to the G-sensor, if the movement time of the device is monitored to exceed the third time interval threshold, waking up the GPS positioning, monitoring the positioning result of the GPS positioning within the fourth time interval threshold, if the GPS positioning is successful, outputting the positioning result, otherwise waking up the WiFi positioning; S4, monitoring the positioning result within the fifth time interval threshold after WiFi positioning is awakened, and outputting the positioning result if WiFi positioning is successful, otherwise waking up LBS positioning; monitoring the positioning result within the sixth time interval threshold after LBS positioning is awakened, and outputting the positioning result if successful, otherwise estimating the coordinate position according to the last stored positioning result and the movement distance estimated by the G-sensor; S5. Monitor the movement of the device after being awakened by GPS positioning. If the device does not move within the seventh time interval threshold, GPS, WiFi, and LBS positioning enter a dormant state; and repeat S4 to monitor the movement of the device.

2. The composite positioning method based on GPS, WiFi and LBS as claimed in claim 1, characterized in that: The access point AP information of the wireless local area network WLAN includes a MAC address and an RSSI, the base station information includes a LAC, a CELLID and an RSSI, and the first time interval is greater than the second time interval.

3. The composite positioning method based on GPS, WiFi and LBS as claimed in claim 1, characterized in that: In S1, the step of obtaining the WiFi positioning result includes: S11, filtering unavailable access point AP data; S12, using an improved recursive average filtering algorithm to remove abnormal data from RSSI data in the available access point AP data; S13, obtaining a WiFi positioning result according to the position of an available access point AP, RSSI data after filtering of the available access point AP, and a Rayleigh fading channel model.

4. The composite positioning method based on GPS, WiFi and LBS as claimed in claim 3, characterized in that: In S12, an improved recursive average filtering algorithm is used to remove abnormal data from RSSI data in the available access point AP data, which specifically includes the following steps: S121, select an available access point AP, and arrange N RSSI data of the available access point AP in ascending order, A1, A2, A3, ...A N ; S122, filter out A1, A2, ...A from the above sequence M , a total of M minimum values, and A N-M+1 , A N-M+2 , ...A N , a total of M maximum values; S123, calculate the average value of the remaining N-2M RSSI data, as shown in formula (1) = (1)； S124, repeat the above steps until the abnormal RSSI data of all available access points AP are eliminated.

5. The composite positioning method based on GPS, WiFi and LBS as claimed in claim 1, characterized in that: In S1, the step of obtaining the LBS positioning result includes: S14, using an improved recursive average filtering algorithm to remove abnormal data from the RSSI data in the base station information; S15, obtaining the latitude and longitude coordinates of the base station according to the base station LAC and CELLID; S16. Obtain LBS positioning results according to the latitude and longitude coordinates of the base station, RSSI data after base station filtering, and Rayleigh fading channel model.

6. The composite positioning method based on GPS, WiFi and LBS as claimed in claim 1, characterized in that: In S2, the initialization of the coordinate position includes: setting the initial coordinate position according to the priority of the positioning success result, wherein GPS priority>WiFi priority>LBS priority; if all three positioning methods fail, setting the initial coordinate position using the preset coordinates.

7. The composite positioning method based on GPS, WiFi and LBS as claimed in claim 1, characterized in that: In S4, when there is only one available access point AP or LBS locates a single base station, the WiFi or LBS positioning result is corrected based on the last coordinate position; the third time interval threshold>(fourth time interval threshold+fifth time interval threshold+sixth time interval threshold), and the seventh time interval threshold>the third time interval threshold.

8. A composite positioning system based on GPS, WiFi and LBS, characterized in that: The system includes the following modules: GPS positioning module, used to implement A-GPS positioning function and obtain GPS positioning results; WiFi positioning module, used to implement WiFi positioning function according to WiFi RSSI value and obtain WiFi positioning result; LBS positioning module, used to implement LBS positioning function according to the RSSI value of the base station and obtain LBS positioning results; G-sensor module, used to wake up the device and monitor its movement, and obtain its movement direction and acceleration; The device coordinate initialization module is used to initialize the device coordinate position according to the GPS, WiFi, LBS positioning results and preset coordinates; The positioning result determination module is used to determine the location of the device based on the stored last positioning coordinates, the movement distance estimated by the G-sensor, and the GPS, WiFi, and LBS positioning results; The monitoring module is used to monitor the continuous motion time of the device, monitor the positioning results and module wake-up of GPS, WiFi, and LBS positioning within the preset time, and sleep the GPS, WiFi, and LBS positioning functions when the device does not move within the preset time; The storage module is used to store the coordinate position of the device, the acquired AP information and base station information, and the calculation result information.

9. The composite positioning system based on GPS, WiFi and LBS as claimed in claim 8, characterized in that: The WiFi positioning module includes the following units: WiFiSCAN unit, used to scan and obtain the wireless access point AP information of the wireless local area network WLAN near the device; A WiFi screening unit is used to screen the AP data obtained by the WiFiSCAN unit to screen out wireless access points AP that can be used for WiFi positioning; An AP position determination unit, used to determine a coordinate position of an access point AP that can be used for positioning; A WiFi abnormal signal filtering unit is used to remove abnormal data from RSSI data in available access point AP data using an improved recursive average filtering algorithm; The WiFi positioning unit is used to obtain the WiFi positioning result according to the position of the available access point AP, the RSSI data after filtering of the available access point AP, and the Rayleigh fading channel model.

10. The composite positioning system based on GPS, WiFi and LBS as claimed in claim 8, characterized in that: The LBS positioning module includes the following units: A base station acquisition unit is used to obtain base station information near the device, including base station LAC, CELLID and RSSI values; A base station location determination unit, used to obtain the coordinate position of the base station according to the base station LAC and CELLID; An RSSI abnormal signal elimination unit is used to eliminate abnormal data using an improved recursive average filtering algorithm for RSSI data in base station information; The base station positioning unit is used to obtain the LBS positioning result according to the latitude and longitude coordinates of the base station, the RSSI data after the base station filtering and the Rayleigh fading channel model.

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