Compound Positioning Method and System Based on GPS, WiFi and LBS

Abstract

The present application discloses a composite positioning method and system based on GPS, WiFi, and LBS, belonging to the field of positioning technology. The system includes: a GPS positioning module, a WiFi positioning module, an LBS positioning module, a G-sensor module, a device coordinate initialization module, a positioning result determination module, a monitoring module, and a storage module. The present application realizes the coordinate position positioning of the device through the GPS positioning module, the WiFi positioning module, and the LBS positioning module, monitors the movement of the device through the G-sensor module, controls the sleep and wake-up of the positioning module and corrects the positioning result, improving the stability and accuracy of positioning, reducing the power consumption of the device, and also solving the positioning drift problem to a certain extent.

Description

Technical Field

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

[0002] With the development of today's society, people use various positioning requirements more and more. In addition to GPS positioning, the requirements for positioning technologies based on Bluetooth, WiFi, LBS, UWB, RFID, etc. are also becoming wider. Each positioning technology has its own applicable scenarios. GPS positioning has high accuracy, but its positioning effect is not good in scenarios such as inside buildings, tunnels, and underground spaces; the positioning accuracy of LBS depends on the base station coverage and the number of base stations, and there is usually an error of 50 - 3000 meters; WiFi positioning depends on the correspondence database between the MAC address of the wireless access point AP and the geographical location, as well as the density of the access points AP available for positioning. At the same time, signal interference will also affect the accuracy of WiFi positioning, and there is usually an error of 10 - 100 meters; positioning technologies such as UWB, RFID, and Bluetooth require additional equipment to be installed, and their applicability is poor.

[0003] Currently, most intelligent devices are integrated with GPS, WiFi, and mobile network modules, and can perform GPS, WiFi, and LBS positioning. With the help of existing positioning technologies, indoor-outdoor integrated positioning can be basically achieved. However, the switching of existing positioning methods is usually based on the recognition of the environment where the intelligent device is located, which requires additional devices such as sensors or is not universal in special scenarios, and depends on the accuracy of indoor-outdoor environment recognition. When the environment recognition is incorrect, the selection of the positioning method is incorrect, resulting in poor positioning effect or positioning failure. In addition, the continuous operation of GPS, WiFi, and LBS positioning will also increase power consumption and waste resources. Summary of the Invention

[0004] Therefore, this application is proposed in view of 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. Compared with the defects of the prior art, it can improve the stability and accuracy of positioning without the need to add additional devices or in special scenarios. At the same time, it can reduce the power consumption of the device to achieve the purpose of 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:

[0007] In the first aspect, this application provides a composite positioning method based on GPS, WiFi, and LBS, and the method includes:

[0008] S1. Obtain the WiFi positioning result based on the access point AP information of the nearby wireless local area network WLAN within the first time interval, and obtain the LBS positioning result based on the base station information nearby within the second time interval;

[0009] S2. Obtain the ephemeris data related to the WiFi positioning or LBS positioning result, and accelerate the GPS positioning through the ephemeris data; Initialize the coordinate position according to the GPS, WiFi, LBS positioning results and the preset coordinates, and the GPS, WiFi, and LBS positioning functions enter the sleep state;

[0010] S3. Monitor the movement of the device according to the G-sensor. If it is detected that the device movement time exceeds the third time interval threshold, wake up the GPS positioning, monitor the positioning result of the GPS positioning within the fourth time interval threshold. If the GPS positioning is successful, output the positioning result, otherwise wake up the WiFi positioning;

[0011] S4. Monitor the positioning result of the WiFi positioning within the fifth time interval threshold after waking up. If the WiFi positioning is successful, output the positioning result, otherwise wake up the LBS positioning; Monitor the positioning result of the LBS positioning within the sixth time interval threshold after waking up. If it is successful, output the positioning result, otherwise estimate the coordinate position according to the last stored positioning result and the movement distance estimated by the G-sensor;

[0012] S5. Monitor the movement of the device after the GPS positioning wakes up. If the device does not move within the seventh time interval threshold, the GPS, WiFi, and LBS positionings enter the sleep state; Repeat to enter S4 to monitor the movement of the device.

[0013] In a second aspect, the present application provides a composite positioning system based on GPS, WiFi, and LBS. The system includes the following modules:

[0014] A GPS positioning module, which is used to implement the A-GPS positioning function and obtain the GPS positioning result;

[0015] A WiFi positioning module, which is used to implement the WiFi positioning function according to the RSSI value of the WiFi and obtain the WiFi positioning result, including the following units:

[0016] A WiFiSCAN unit, which is used to scan and obtain the wireless access point AP information of the wireless local area network WLAN near the device;

[0017] A WiFi screening unit, which is used to screen the AP data obtained by the WiFiSCAN unit and screen out the wireless access points AP that can be used for WiFi positioning;

[0018] An AP position determination unit for determining the coordinate positions of access points (APs) available for positioning;

[0019] A WiFi abnormal signal filtering unit for removing abnormal data from the RSSI data in the available AP data using an improved recursive average filtering algorithm;

[0020] A WiFi positioning unit for obtaining a WiFi positioning result based on the positions of available APs, the filtered RSSI data of available APs, and the Rayleigh fading channel model;

[0021] An LBS positioning module for implementing the LBS positioning function based on the RSSI values of base stations and obtaining the LBS positioning result, including the following units:

[0022] A base station acquisition unit for acquiring information about base stations near the device, including the base station LAC, CELLID, and RSSI values;

[0023] A base station position determination unit for obtaining the coordinate positions of base stations based on the base station LAC and CELLID;

[0024] An RSSI abnormal signal removal unit for removing abnormal data from the RSSI data in the base station information using an improved recursive average filtering algorithm;

[0025] A base station positioning unit for obtaining the LBS positioning result based on the longitude and latitude coordinates of the base station, the filtered RSSI data of the base station, and the Rayleigh fading channel model;

[0026] A G-sensor module for waking up the device and monitoring the movement of the device to obtain the movement direction and acceleration of the device;

[0027] A device coordinate initialization module for initializing the coordinate position of the device based on the GPS, WiFi, LBS positioning results, and preset coordinates;

[0028] A positioning result determination module for determining the position of the device based on the last stored positioning coordinates, the movement distance estimated according to the G-sensor, and the GPS, WiFi, LBS positioning results;

[0029] A monitoring module for monitoring the continuous movement time of the device, monitoring the positioning results within a predetermined time of GPS, WiFi, LBS positioning, and module wake-up, and putting the GPS, WiFi, LBS positioning functions into sleep mode when the device does not move within a predetermined time;

[0030] A storage module for storing the coordinate position of the device, the obtained AP information, base station information, and calculation result information.

[0031] Compared with the prior art, the beneficial effects of the present invention are at least as follows:

[0032] The compound positioning method and system based on GPS, WiFi and LBS of the present application filters abnormal data from the RSSI data in the collected WiFi or base station information using an improved recursive average filtering algorithm, reduces the influence of noise on the positioning result, improves the positioning accuracy, and accelerates the GPS positioning process by obtaining ephemeris data from the positioning result of WiFi or base station; monitors 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; improves the positioning stability 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 previous positioning result and the estimated moving distance according to the G-sensor, improving the positioning accuracy and also solving the positioning drift problem to a certain extent. Brief Description of the Drawings

[0033] Figure 1 Illustrates a method flow chart of a compound positioning method based on GPS, WiFi and LBS according to an embodiment of the present application;

[0034] Figure 2 Illustrates a method flow chart of obtaining a WiFi positioning result according to access point AP information according to an embodiment of the present application;

[0035] Figure 3 Illustrates a method flow chart of using an improved recursive average filtering algorithm to remove abnormal data from RSSI data in available access point AP data according to an embodiment of the present application;

[0036] Figure 4 Illustrates a method flow chart of obtaining an LBS positioning result according to an embodiment of the present application;

[0037] Figure 5 Illustrates a schematic diagram of a compound positioning system based on GPS, WiFi and LBS according to an embodiment of the present application. Detailed Embodiment

[0038] Next, exemplary embodiments according to the present application will be described in detail with reference to the drawings. It should be understood that the specific embodiments described herein are only a part of the embodiments of the present application, and the present application is not limited by the exemplary embodiments described herein.

[0039] Please refer to Figure 1 , which shows a method flow chart of a compound positioning method based on GPS, WiFi and LBS according to an embodiment of the present application. The compound positioning method based on GPS, WiFi and LBS includes:

[0040] S1. Obtain the WiFi positioning result according to the access point AP information of the nearby wireless local area network WLAN within the first time interval, and obtain the LBS positioning result according to the base station information nearby within the second time interval;

[0041] The composite positioning method and system based on GPS, WiFi and LBS provided by the embodiments of the present application are applied to a communication device. The communication device is equipped with a SIM card and a gravity acceleration sensor G-sensor, and has a WiFiSCAN function at the same time. After the device is powered on, the system completes initialization. The access point AP information of the nearby wireless local area network WLAN is scanned and obtained through the WiFiSCAN function. The access point AP information includes MAC (Media Access Control Address) and RSSI (Received Signal Strength Indication). The scanning time can be set within a predetermined time range, for example, continuous scanning can be performed within 10 to 15 seconds. After each successful scan, the access point AP information is stored in an array. The data in the array is in dictionary form, with the MAC address of the access point AP as the key and the array storing RSSI as the value. After scanning for the predetermined time length, the array storing the access point AP information is sent to the server for processing; the nearby base station information connected is obtained through the SIM card. The base station information includes LAC (Location Area Code), CELLID (CELL Identification), and RSSI. The scanning time can also be the set predetermined time length, for example, continuous scanning is performed within 5-10 seconds to obtain. 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 scanning for the predetermined time length, the array storing the base station information is sent to the server for processing;

[0042] After the server receives the array storing the access point AP information of the wireless local area network WLAN sent by the device, it processes the data to obtain the first WiFi positioning result. The specific process can refer to Figure 2 as shown, and specifically includes the following steps:

[0043] S11. Filter out unavailable access point AP data;

[0044] 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;

[0045] S12, using an improved recursive average filtering algorithm to remove abnormal data from RSSI data in the available access point AP data;

[0046] 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:

[0047] 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 ;

[0048] 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 ;

[0049] 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;

[0050] 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.

[0051] S123, calculate the average value of the remaining N-2M RSSI data, as shown in formula (1)

[0052] = (1);

[0053] S124. Repeat the above steps until all the RSSI abnormal data of the available access points AP are removed;

[0054] For the case where there are multiple access points AP in the available access points AP array, repeat the above processing steps until the RSSI data of all the access points AP in the array are removed for abnormal data once;

[0055] Return reference Figure 2 , in step S13, obtain the WiFi positioning result according to the available access point AP location, the filtered RSSI data of the available access point AP, and the Rayleigh fading channel model;

[0056] Find the location coordinates of the access point AP from the data stored in the server according to the MAC address of the available access point AP, construct the WiFi signal strength fading change curve by the Rayleigh fading channel model, use the KNN algorithm to find K nearest neighbor points according to the RSSI fading change curve and the filtered RSSI value of the available access point AP. If the number of available access points AP is more than one, the final nearest neighbor point can be determined as the device location according to the nearest neighbor points determined by multiple access points AP, and then calculate the coordinates of the device according to the coordinates of one or more access points AP and the determined nearest neighbor points;

[0057] Return reference Figure 1 , in step S1, after the server receives the array storing the base station information sent by the device, process the data to obtain the first LBS positioning result. The specific process can refer to Figure 4 shown as follows:

[0058] S14. Use the improved recursive average filtering algorithm to remove the abnormal data from the RSSI data in the base station information;

[0059] There are abnormal data in the RSSI data of the obtained base station information due to the influence in the propagation process. Therefore, it is also necessary to process the RSSI data in the same way as in WiFi positioning. The processing process is similar to that in WiFi positioning. For the obtained array storing the base station information, select the base station one by one and use the improved recursive average filtering algorithm to remove the abnormal data in the RSSI data, and finally obtain the highly reliable RSSI value corresponding to the base station;

[0060] S15. Obtain the longitude and latitude coordinates of the base station according to the base station LAC and CELLID;

[0061] The server queries the location of the base station through the LAC and CELLID of the base station to obtain the longitude and latitude coordinates corresponding to the base station. If there are multiple base station information, the coordinate positions corresponding to multiple base stations can be obtained;

[0062] S16. Obtain the LBS positioning result based on the longitude and latitude coordinates of the base station, the filtered RSSI data of the base station, and the Rayleigh fading channel model;

[0063] Construct a curve of the RSSI signal strength fading change of the base station according to the Rayleigh fading channel model. Use the KNN algorithm to find K nearest neighbor points according to the RSSI fading change curve and the filtered RSSI value of the base station. If there is more than one base station, the final nearest neighbor point can be determined as the device location according to the nearest neighbor points determined by multiple base stations, and then the coordinates of the device can be calculated according to the coordinates of one or more base stations and the determined nearest neighbor points;

[0064] Return reference Figure 1 In step S2, obtain ephemeris data related to the WiFi positioning or LBS positioning result, and accelerate the GPS positioning through the ephemeris data; initialize the coordinate position according to the GPS, WiFi, LBS positioning results and the preset coordinates, and the GPS, WiFi, LBS positioning functions enter the sleep state;

[0065] Since the first GPS positioning requires satellite search and other operations, which leads to a long positioning time, at this time, the A-GPS assisted positioning method needs to be adopted to accelerate the positioning process; the WiFi or LBS positioning is faster, and the ephemeris and other data can be downloaded according to the rough-precision coordinate position obtained by the WiFi or LBS positioning, and then the ephemeris data is loaded into the GPS positioning chip to realize the A-GPS function and accelerate the GPS positioning process; when the GPS positioning fails, it will be repeated N times. If the N positioning attempts all fail, it is determined that the current GPS cannot be positioned;

[0066] Due to the relationship of the positioning accuracies of GPS positioning, WiFi positioning, and LBS positioning, the credibility of the three positioning methods when the positioning is successful is sorted. Among them, GPS priority > WiFi priority > LBS priority. That is to say, first take the coordinates of the successful GPS positioning to initialize the coordinates of the device. If the GPS positioning fails, take the coordinates of the successful WiFi positioning to initialize the device coordinates. If the WiFi positioning fails, take the coordinates of the successful LBS positioning to initialize the device coordinates; if none of the three positioning methods are successful, initialize the device coordinate position according to the preset fixed coordinate position of the device; at this time, the GPS, WiFi, LBS positioning functions can be put into the sleep state to reduce the power consumption of the device;

[0067] S3. Monitor the movement of the device according to the G-sensor. If the monitored movement time of the device exceeds the third time interval threshold, wake up the GPS positioning, monitor the positioning result of the GPS positioning within the fourth time interval threshold. If the GPS positioning is successful, output the positioning result; otherwise, wake up the WiFi positioning.

[0068] According to the movement state of the device monitored by the G-sensor, when the G-sensor monitors that the device is in a moving state and the movement time exceeds the third time interval threshold, wake up the GPS positioning function of the device to perform a positioning operation to determine the location of the device at this time. For example, the third time interval threshold can be 5 - 10 seconds, and no specific limitation is made here; after waking up the GPS positioning, monitor the positioning result of the GPS positioning within the fourth time interval threshold. If the GPS positioning is successful within the fourth time interval threshold, set the device location at this time according to the GPS positioning result. If the GPS positioning fails, wake up the WiFi positioning function to determine the location of the device at this time. The fourth time interval threshold can be 2 - 5 seconds, and no limitation is made here.

[0069] S4. Monitor the positioning result of the WiFi positioning within the fifth time interval threshold after it is awakened. If the WiFi positioning is successful, output the positioning result; otherwise, wake up the LBS positioning. Monitor the positioning result of the LBS positioning within the sixth time interval threshold after it is awakened. If it is successful, output the positioning result; otherwise, estimate the coordinate position according to the last stored positioning result and the movement distance estimated based on the G-sensor.

[0070] After waking up the WiFi positioning function, enable the WiFi SCAN function to scan the nearby wireless access points AP within a predetermined duration. According to the wireless access point AP information obtained by the scan, perform WiFi positioning using the steps of S11 - S13 in the above reference Figure 2 Monitor the positioning result of the WiFi positioning within the fifth time interval threshold. If the WiFi positioning is successful, use the coordinates of the WiFi positioning as the coordinate position of the device at this time; otherwise, wake up the LBS positioning function to determine the location of the device. Among them, the fifth time interval threshold can be 2 - 3 seconds, and no limitation is made here; preferably, if the wireless access point AP obtained at this time has not changed and the processed RSSI value has not changed significantly, use the result of the previous WiFi positioning as the result of this positioning; 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, at this time, the WiFi positioning result can be corrected according to the coordinates of the previous successful positioning and the moving distance estimated based on the G-sensor, and the final coordinates of the device can be determined.

[0071] When the WiFi positioning fails, wake up the LBS positioning function for the final positioning attempt. The LBS positioning process is the same as the above referenceFigure 4 The steps of S14 - S16 are the same. Monitor the positioning results of LBS positioning within the sixth time interval threshold, and 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, use the base station positioning result at this time as the coordinate of the device at this time. If the base station positioning is not successful either, determine the coordinate position of the device according to the last positioning result stored in the system, that is, the previous positioning result, the movement distance estimated according to the G-sensor, and the measured acceleration direction; if there is only one piece of base station information obtained during this base station positioning, correct the base station positioning result according to the steps when positioning with a single access point AP as described above; due to the need to continuously obtain the device position change to draw trajectory points, the total duration of GPS, WiFi, and LBS positioning should be less than the duration of monitoring the device movement when responding to the positioning wake-up, that is, the third time interval threshold > (the fourth time interval threshold + the fifth time interval threshold + the sixth time interval threshold);

[0072] S5. Monitor the movement of the device after the GPS positioning wake-up. If the device does not move within the seventh time interval threshold, the GPS, WiFi, and LBS positioning enter the sleep state; repeat to enter S3 to monitor the movement of the device.

[0073] After the GPS positioning function is woken up, continuously monitor the movement of the device according to the G-sensor. If it is detected that the device moves and exceeds the third time interval threshold, continue with the positioning operation to determine the device position. If the device movement is not detected within the seventh time interval threshold after the positioning function is woken up, let the GPS, WiFi, and LBS positioning functions enter the sleep state to reduce the power consumption of the device. At this time, still monitor the movement state of the device according to the G-sensor to wake up the positioning function; in order to avoid frequent sleep and wake-up of the positioning module, the seventh time interval threshold should be much larger than the third time interval threshold.

[0074] Next, refer to Figure 5 to describe a composite positioning system based on GPS, WiFi, and LBS according to an embodiment of the present application. As Figure 5 shown, the composite positioning system based on GPS, WiFi, and LBS includes:

[0075] A GPS positioning module, used to implement the A-GPS positioning function and obtain the GPS positioning result;

[0076] 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 result, and realize sleep and wake-up according to the G-sensor module and the monitoring module to achieve the purpose of reducing power consumption;

[0077] 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:

[0078] WiFiSCAN unit, used to scan and obtain the wireless access point AP information of the wireless local area network WLAN near the device;

[0079] 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;

[0080] An AP position determination unit, used to determine a coordinate position of an access point AP that can be used for positioning;

[0081] 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;

[0082] 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;

[0083] 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:

[0084] A base station acquisition unit is used to obtain base station information near the device, including base station LAC, CELLID and RSSI values;

[0085] A base station location determination unit, used to obtain the coordinate position of the base station according to the base station LAC and CELLID;

[0086] 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;

[0087] 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;

[0088] G-sensor module, used to wake up the device and monitor its movement, and obtain its movement direction and acceleration;

[0089] The device coordinate initialization module is used to initialize the device coordinate position according to the GPS, WiFi, LBS positioning results and preset coordinates;

[0090] 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;

[0091] A monitoring module, configured to monitor the continuous movement time of the device, monitor the positioning results and module wake-up within a predetermined time for GPS, WiFi, and LBS positioning, and put the GPS, WiFi, and LBS positioning functions into sleep mode when the device does not move within a predetermined time.

[0092] A storage module, configured to store the coordinate position of the device, the obtained AP information, base station information, and calculation result information.

[0093] The specific functions and operations of each module and each unit in the above composite positioning system based on GPS, WiFi, and LBS have been introduced in detail in a composite positioning method based on GPS, WiFi, and LBS described above. Therefore, the repeated description thereof will be omitted here.

[0094] The basic principles of the present application have been described in combination with specific embodiments. It should be understood that the above disclosed specific details are only for the purpose of illustration and easy understanding, rather than limitation, and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope 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 according to claim 1, wherein 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 according to 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 according to claim 3, wherein, 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 sort the N RSSI data of the available access point AP in ascending order, A1, A2, A3,... A N ; S122. Filter out A1, A2,... A 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 according to claim 1, wherein 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 according to 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 according to claim 1, wherein 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 for implementing the composite positioning method according to any one of claims 1-7, 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 according to 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 according to 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; A base station positioning unit, which is used to obtain an LBS positioning result according to the longitude and latitude coordinates of the base station, the filtered RSSI data of the base station, and the Rayleigh fading channel model.

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