Device and method for constructing and updating fingerprint map based on indoor environment characteristics

Abstract

The invention belongs to the technical field of indoor navigation, and particularly relates to a device and a method for constructing and updating a fingerprint map based on indoor environment characteristics. Building an indoor electronic map of the building and a corresponding initial fingerprint map, and obtaining an indoor environment landmark of the moving target in real time through a sensor based on the moving condition of the moving target in the building; the indoor environment landmarks are matched to an indoor electronic map of the building through a map matching algorithm, and position coordinates are obtained; the relation between the indoor environment landmark and the fingerprint reference point is judged according to the position coordinate, and then the fingerprint map is updated according to the new fingerprint signal of the indoor environment landmark. According to the invention, the inertial sensor is used for sensing and identifying indoor environment characteristics in real time, accurate positioning of environment landmark positions is realized based on a map matching technology, and finally, the fingerprint map updating module is used for updating an indoor fingerprint map in real time, so that the freshness of the fingerprint map is ensured, and the reliability and long-term stability of the precision of the indoor fingerprint map are realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of indoor navigation, and in particular relates to a device and method for constructing and updating a fingerprint map based on indoor environmental characteristics. Background Art

[0002] As technology enters the era of the Internet of Everything, indoor location services have become a core technology that urgently needs to be broken through in the fields of the Internet of Things and emergency rescue, and indoor positioning technology is the bottleneck technology of indoor location services. Indoor positioning technologies mainly include: wireless signal positioning technology, such as GNSS (Global Navigation Satellite System), WIFI (Wireless Fidelity) positioning, UWB (Ultra Wide Band) positioning, RFID (Radio Frequency Identification) positioning, etc. Due to the complexity of the indoor environment, the signal attenuation or inability to pass through the building's obstruction causes poor positioning accuracy or even no positioning. Perception positioning technology, such as inertial positioning technology and visual positioning technology, generally belongs to relative positioning, and the positioning error accumulates over time; combined positioning technology, that is, the advantages of different positioning technologies are gathered to make up for their own disadvantages, and the strengths and weaknesses are used to improve the positioning accuracy of the system. Inertial positioning technology does not rely on the independent positioning performance of any external signal, and MEMS (Micro Electronic Mechanical Systems) inertial sensors can be quickly and conveniently implanted in any mobile device, but its positioning accuracy accumulates over time, and it has the characteristics of high short-term positioning accuracy. In addition, with the widespread coverage of WIFI indoors, new indoor positioning technologies based on WIFI fingerprint maps have developed rapidly. Currently, WIFI fingerprint map / inertial combined positioning has become the main technical solution for the research and application of indoor positioning systems.

[0003] A fingerprint in the WiFi fingerprint map is the AP at the reference point at the time of offline data sampling. j The sampling of signal strength distribution causes dynamic changes in the local characteristics of fingerprint signal strength and intensity distribution due to changes in indoor propagation media, propagation paths, and signal source status, which leads to the problem of fingerprint map accuracy degradation over time, restricting its positioning accuracy.

[0004] Wifi signals are fully covered in indoor environments, so the fingerprint map positioning method is suitable for a wide range of indoor positioning scenarios in terms of accuracy, system deployment difficulty, and cost. However, fingerprint maps have time-varying characteristics and the problem of accuracy degradation over time. To address this problem, the core is to maintain the "freshness" of fingerprint maps, that is, to increase the update frequency of fingerprint maps. Currently, crowdsourcing collection schemes are mainly adopted. Crowdsourcing users use their own terminal devices to collect current RSS data, sensor data, timestamps and other data in real time to generate crowdsourcing fingerprints to achieve real-time updates of fingerprint maps, so as to achieve the goal of "freshness" of fingerprint maps. Fingerprints are a collection of RSS data and reference point location information. Based on crowdsourcing collection schemes, RSS data of a reference point can be accurately collected in real time. However, if the reference point location information is inaccurate, the corresponding fingerprint signal will inevitably be inaccurate. Therefore, obtaining high-precision location information of the reference point is a difficult problem that needs to be solved urgently.

[0005] The main devices currently include: using multi-dimensional scaling technology to calculate location information, based on contextual neighbor data and indoor points of interest, based on inertial dead reckoning and a small number of fixed Bluetooth beacons as location references. These devices are designed based on real-time crowdsourcing collection by mobile users, reducing the huge labor cost of updating fingerprint maps. However, for the location of fingerprint reference points, the location accuracy is mainly corrected based on relative position calculation devices, and there is a lack of absolute precise location points to correct the reference point position, which leads to reduced fingerprint map accuracy and even inability to locate.

[0006] The real-time automatic update technology of device fingerprint map is one of the core technologies that need to be solved in the current indoor positioning technology, and the realization of automatic and accurate positioning technology in the process of data collection is its bottleneck. The current automatic and accurate positioning technology in the real-time update of fingerprint maps is mainly based on relative position calculation devices, or based on path matching devices to correct the positioning accuracy. The positioning accuracy errors of these devices will accumulate over time. Therefore, it is urgent to find a method based on absolutely accurate location point information to correct the accumulated error. Summary of the invention

[0007] The purpose of the present invention is to provide a device and method for constructing and updating a fingerprint map based on indoor environment characteristics, to correct the accumulated errors of the automatic precise positioning technology based on the precise location information of indoor environment landmarks, and thus to achieve the reliability and long-term stability of the indoor fingerprint map accuracy.

[0008] To achieve the above object, the present invention provides a device for constructing and updating a wifi fingerprint map based on indoor environment characteristics, comprising:

[0009] The sensor-based feature landmark recognition module is used to sense and identify indoor environment landmarks by tracking the motion state of moving targets in real time through sensors;

[0010] An environmental landmark location positioning module based on map matching is used to match the indoor environmental landmark to the constructed indoor electronic map of the building through a map matching algorithm to obtain the location coordinates of the indoor environmental landmark;

[0011] The wifi fingerprint map construction and update module is used to construct an initial wifi fingerprint map, determine the relationship between the indoor environment landmark and the fingerprint reference point according to the location coordinates, and then update the wifi fingerprint map according to the new wifi fingerprint signal of the indoor environment landmark.

[0012] Further, the sensor includes one or more of an inertial sensor, a visual sensor, a barometer, and a magnetic sensor, and the inertial sensor includes a gyroscope and an accelerometer;

[0013] And / or, the indoor environment landmarks include corridors, corridor turning points, door turning points, elevator shafts, and stairwells.

[0014] Furthermore, the sensor is the inertial sensor; the feature landmark recognition module uses the angle changes sensed by the gyroscope to identify the corridor turning points, door turning points and corridors in the indoor environment landmarks, and uses the acceleration changes sensed by the accelerometer to identify the elevator shaft and stairwell in the indoor environment landmarks.

[0015] Furthermore, the road network of the indoor electronic map of the building is composed of corridors and environmental feature landmarks, the corridors constitute the roads in the road network of the indoor electronic map, and the environmental feature landmarks constitute the link nodes between road segments in the road network;

[0016] The environmental feature landmarks include corridor turning points, door turning points, elevator shafts, and stairwells.

[0017] Furthermore, the sensor is from a mobile terminal device carried by the mobile target, and the new wifi fingerprint signal is collected by the mobile terminal device carried by the mobile target.

[0018] Furthermore, the wifi fingerprint map construction and update module stores the originally collected wifi fingerprint map, and the wifi fingerprint map includes fingerprint reference points and their corresponding wifi fingerprint signals;

[0019] When the difference between the new WiFi fingerprint signal of the indoor environment landmark and the fingerprint signal before the update exceeds a preset threshold, the new WiFi fingerprint signal is used as the WiFi fingerprint signal after the corresponding fingerprint reference point is updated.

[0020] Furthermore, the relationship between the indoor environment landmark and the fingerprint reference point includes three situations. The first situation is: the indoor environment landmark coincides with the fingerprint reference point. Then, when the difference between the new wifi fingerprint signal of the indoor environment landmark and the wifi fingerprint signal before the update is greater than a preset threshold, the new wifi fingerprint signal is directly used as the updated wifi fingerprint signal of the corresponding fingerprint reference point;

[0021] The second case is: if the indoor environment landmark is not a fingerprint reference point, the wifi fingerprint signal of the indoor environment landmark is directly inserted into the wifi fingerprint map as a new fingerprint reference point;

[0022] The third case is: based on the wifi fingerprint signals before and after the update of several fingerprint reference points in the area, the change error of the wifi fingerprint signal is obtained, and the signal fingerprint of all fingerprint reference points in the area is updated; wherein, the new wifi fingerprint signal of the fingerprint reference point is as shown in formula (1), and the old wifi fingerprint signal is as shown in formula (2). According to the error between the new and old fingerprint signals, an error model is constructed, such as formula (3). Based on the error model, when When it is greater than the preset threshold, Update the signal fingerprints of all fingerprint reference points in the fingerprint map area in real time;

[0023]

[0024] in, represents the new wifi fingerprint signal of the i-th fingerprint reference point in the fingerprint map, Indicates the AP corresponding to the i-th new WiFi fingerprint signal j Signal strength RSS; represents the old fingerprint signal of the i-th fingerprint reference point in the fingerprint map, Indicates the AP corresponding to the i-th old fingerprint signal j signal strength RSS; i, j and n are natural numbers, n represents the total number of APs at the i-th fingerprint reference point, and j represents the j-th AP.

[0025] The present invention also provides a method for constructing and updating a wifi fingerprint map based on indoor environmental characteristics. First, an indoor electronic map of a building and a corresponding initial wifi fingerprint map are constructed. Then, based on the movement of the mobile target in the building, the indoor environmental landmarks of the mobile target are acquired in real time through sensors. The indoor environmental landmarks are matched to the indoor electronic map of the building through a map matching algorithm to obtain the position coordinates of the indoor environmental landmarks. The relationship between the indoor environmental landmarks and the fingerprint reference points is first determined according to the position coordinates, and then the wifi fingerprint map is updated according to the new wifi fingerprint signal of the indoor environmental landmark.

[0026] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the wifi fingerprint map construction and update method as described above is implemented.

[0027] In general, the above technical solution conceived by the present invention has the following technical advantages compared with the prior art:

[0028] 1. The device for constructing and updating a wifi fingerprint map based on indoor environmental features provided by the present invention combines a map matching algorithm with an indoor electronic map to obtain precise location point coordinates of indoor special environmental features, and then corrects the location coordinates of wifi fingerprint reference points, which can improve the accuracy of the fingerprint map in real time, thereby ensuring the "freshness" of the fingerprint map and achieving the reliability and long-term stability of the indoor fingerprint map accuracy.

[0029] 2. The present invention is based on the inertial sensor of the mobile terminal device carried by the mobile target to perceive and identify the special indoor environmental features in real time, and obtain the precise location of the special indoor environmental features, which can supplement and improve the layout of the wifi fingerprint reference points in real time.

[0030] 3. The present invention updates the fingerprint map by category according to the type of environmental landmarks, which can not only improve the layout of the wifi fingerprint reference points, but also update the fingerprint signals of the existing reference points in real time, making the update convenient, timely and accurate. In addition, the error model is used to update the fingerprint signals in the entire area based on a small number of existing fingerprint signals in the area. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A block diagram of the composition of the device for constructing and updating a wifi fingerprint map based on indoor environment characteristics provided by the present invention.

[0032] Figure 2 Motion characteristics corresponding to different indoor environment landmarks.

[0033] Figure 3 It is an indoor electronic map of part of a building.

[0034] Figure 4 This is a schematic diagram of the interior plan of part of a building.

[0035] Figure 5 Schematic diagram of the composition of the inertial navigation system.

[0036] Figure 6 Schematic diagram of fingerprint map based on indoor environment characteristics in part of a building. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0038] The present invention provides a device for constructing and updating a wifi fingerprint map based on indoor environmental characteristics, which uses an inertial sensor to perceive and identify indoor environmental characteristics in real time, and uses map matching technology to accurately locate the location of environmental landmarks. Finally, a fingerprint map update module is used to update the indoor fingerprint map in real time, thereby achieving reliability and long-term stability of indoor fingerprint map accuracy. A wifi fingerprint map refers to the wireless access point signal AP received at a certain indoor reference point. j Signal strength information RSS j A set of, where j = 1, 2, ..., n, n is the number of wireless access point signals AP that can be received at the location reference point. Storing all Wifi fingerprints in a certain area forms a Wifi fingerprint map.

[0039] Specifically, see Figure 1 , a fingerprint map construction and updating device based on indoor environment characteristics, comprising:

[0040] The sensor-based feature landmark recognition module is used to sense and identify indoor environment landmarks by tracking the motion state of moving targets in real time through sensors;

[0041] An environmental landmark location positioning module based on map matching is used to match the indoor environmental landmark to the constructed indoor electronic map of the building through a map matching algorithm to obtain the location coordinates of the indoor environmental landmark;

[0042] The wifi fingerprint map construction and update module is used to construct an initial wifi fingerprint map, determine the relationship between the indoor environment landmark and the fingerprint reference point according to the location coordinates, and then update the wifi fingerprint map according to the new wifi fingerprint signal of the indoor environment landmark.

[0043] Among them, the characteristic landmark recognition module based on sensor perception uses inertial sensors (such as gyroscopes, accelerometers), visual sensors, barometers, and magnetic sensors. The module in the present invention mainly uses inertial sensors to track the motion state of mobile targets in real time to perceive and identify the iconic environmental landmark features of indoor buildings. Its composition is mainly based on the inertial navigation system already included in the mobile terminal device currently carried by the mobile target. The angle changes perceived by the gyroscope are used to identify the iconic environmental landmark features such as corners and corridors of indoor buildings; the acceleration changes perceived by the accelerometer are used to identify the iconic environmental landmark features such as elevators and stairs.

[0044] Since there are a large number of environmental landmarks of the same type indoors, and there are errors in the location coordinate information obtained during the crowdsourcing data collection process, it is impossible to accurately locate the landmark only through the collected data, nor can it distinguish environmental landmarks with similar locations and similar types. The precise positioning module of the environmental landmark position based on map matching in the present invention is intended to obtain the precise location coordinates of the identified environmental landmarks based on the indoor electronic map of the building, combined with the map matching technology, so as to achieve precise positioning of the environmental landmarks. The indoor environmental landmarks of the present invention include corridors, corridor turning points, door turning points, elevator shafts and stairwells, and the indoor electronic map is also composed of corridors, corridor turning points, door turning points, elevator shafts and stairwells, that is, it does not involve the positioning of rooms such as offices and fingerprint map updates. Map matching technology is a more mature precise positioning technology in vehicle navigation systems. It is a technology that uses digital map information to fuse sensor positioning data to generate the best position estimate. After receiving information about the vehicle at the current moment, relevant information is obtained from the electronic map database, and then the deviation information of the vehicle position is obtained through the map matching algorithm, and it is corrected in real time, so as to accurately display the position of the vehicle. Based on the similarity between indoor electronic maps and road electronic maps, the present invention combines the map matching algorithm of vehicle navigation with the indoor electronic map to achieve accurate positioning of mobile targets, thereby improving the reliability and long-term stability of fingerprint map accuracy.

[0045] The wifi fingerprint map construction and update module stores the original collected wifi fingerprint map, which includes fingerprint reference points and their corresponding wifi fingerprint signals. When the difference between the new wifi fingerprint signal of the indoor environment landmark and the fingerprint signal before the update exceeds the preset threshold, the new wifi fingerprint signal is used as the updated wifi fingerprint signal of the corresponding fingerprint reference point, thereby ensuring the "freshness" of the fingerprint map.

[0046] The fingerprint map update module uses the environmental landmark points of the mobile target as the landmark reference points of the fingerprint map. The update of the fingerprint map is mainly divided into three categories. The first category is: the reference point in the current fingerprint map is a landmark reference point and is the currently identified landmark reference point. The signal fingerprint of the reference point in the current fingerprint map is directly updated; the second category is: the current landmark reference point is not a reference point in the fingerprint map. A new reference point fingerprint is inserted into the fingerprint map and marked as a landmark reference point; the third category is: based on the fingerprint signals before the update (ie, the old fingerprint signal) and the updated fingerprint signals (ie, the new wifi fingerprint signal) of several landmark reference points in a certain indoor area, the change error of the fingerprint signal is obtained and the signal fingerprints of all fingerprint maps in the area are updated.

[0047] Specifically, the sensor-based feature landmark recognition module of the present invention mainly includes an inertial navigation system, such as Figure 5 As shown in the figure, most mobile terminals are equipped with this system. It mainly consists of three gyroscopes and three accelerometers installed orthogonally in pairs, respectively measuring and obtaining the motion information of the vehicle along the three axes of X, Y, and Z. This module obtains the motion information of the vehicle in real time based on the inertial navigation system to identify the characteristic landmarks of the indoor environment, such as Figure 6 The environmental feature landmarks of the mid-inflection points (corridors, corridor inflection points, door inflection points) are mainly identified based on the heading angle change information in the vehicle motion information measured by the gyroscope in the inertial navigation system. Figure 2 The signal characteristic of the inertial navigation system of the corridor landmark is that the vehicle motion information maintains linear motion for a long time, that is, the heading angle in the inertial navigation system remains unchanged for a long time. Here, "remaining unchanged for a long time" mainly refers to being unchanged within the range of gyroscope drift error. The signal characteristic of the inertial navigation system of the corridor turning point and door turning point landmarks is that the vehicle motion information produces a large heading angle change from the current linear motion segment to the next linear motion segment. The elevator and stair environmental feature landmarks are mainly identified based on the changes in the vehicle motion information along the Z axis measured by the accelerometer in the inertial navigation system.

[0048] Furthermore, the environment landmark location positioning module based on map matching described in the present invention mainly includes an indoor electronic map of a building and a map matching algorithm. Figure 3 As shown, Figure 4 The indoor floor plan is simplified into an electronic map such as Figure 3 As shown in the figure, it mainly includes corridors and environmental feature landmarks. The corridors mainly constitute the road network of the indoor electronic map. Figure 3The road network consists of 19 road segments, including AH1, H1H2, H2B, BF, FC, CK4, K4D, DN1, DN2, N2N3, N3E, EK3, K3K2, K2K1, K1F, EN4, N4N5, N5N6 and N6A. Environmental feature landmarks mainly constitute the link nodes between road segments in the road network, such as Figure 3 The H1 and H2 nodes are door turning point landmarks; K1 and K3 are elevator and stair landmarks, respectively, which are link nodes of road segments between floors.

[0049] like Figure 3 As shown, a certain existing vehicle moves along the corridor ABFCDEA trajectory for one circle. The vehicle movement trajectory provided in real time by the inertial navigation system carried by the vehicle itself is A1-B1-C1-D1-A2. There is a large error between the ABFCDEA trajectory and A1-B1-C1-D1-A2. It is necessary to use the accurate trajectory information of ABFCDEA provided by the electronic map and use a map matching algorithm (such as a hidden Markov model) to match the vehicle trajectory A1-B1-C1-D1-A2 obtained by the inertial navigation system to the ABFCDEA trajectory, so as to obtain accurate position information.

[0050] The fingerprint map updating module of the present invention uses environmental landmark points as landmark reference points of the fingerprint map, and the updating of the fingerprint map is mainly divided into three categories.

[0051] For the first type of situation, such as Figure 6 Point G in the figure is the landmark of the corridor turning point and also the fingerprint reference point in the fingerprint map. When the precise positioning module of the environmental landmark position based on map matching identifies and obtains that the crowdsourcing user's mobile terminal is at point G, and the difference between the new wifi fingerprint signal of the indoor environmental landmark and the wifi fingerprint signal before the update is greater than the preset threshold, the fingerprint map update module directly uses the signal fingerprint collected by the terminal user in real time to update the signal fingerprint of the fingerprint point at point G, and marks the point as the landmark reference point of the fingerprint map.

[0052] For the second case, such as Figure 6 Point H in the figure is a staircase landmark. In the original fingerprint map, the landmark point H is not a fingerprint reference point in the fingerprint map. When the precise positioning module of the environmental landmark position based on map matching identifies and obtains the crowdsourcing user's mobile terminal at point H, the fingerprint map update module directly uses the signal fingerprint collected in real time by the mobile terminal as a new fingerprint point to add to the fingerprint map, and marks the point as a fingerprint map landmark reference point.

[0053] For the third category, such as Figure 6In the middle elliptical area, there are abundant landmark points in and around the area, which are also fingerprint points in the fingerprint map. If the fingerprint signals of these landmark points, which are also fingerprint points, are updated in real time within a certain period of time, the fingerprint map update module will build an error model (such as formula (3)) based on the error between the new wifi fingerprint signals (such as formula (1)) and the old fingerprint signals (such as formula (2)) of these landmark points. When it is greater than the preset threshold, Update the signal fingerprints of all fingerprint reference points in the fingerprint map area in real time:

[0054]

[0055] in, represents the new wifi fingerprint signal of the i-th fingerprint reference point in the fingerprint map, Indicates the AP corresponding to the i-th new WiFi fingerprint signal j Signal strength RSS; represents the old fingerprint signal of the i-th fingerprint reference point in the fingerprint map, Indicates the AP corresponding to the i-th old fingerprint signal j signal strength RSS; i, j and n are natural numbers, n represents the total number of APs at the i-th fingerprint reference point, and j represents the j-th AP.

[0056] The current data collection form of indoor navigation is crowdsourcing mode, that is, in a certain period or time point, there may be multiple mobile targets (i.e. multiple mobile terminals) in the area that will collect data simultaneously or in time-sharing and upload it to the data center. For example, if the fingerprint map has 50 fingerprint points in the area, if there are 5 or more automatically identified fingerprint points in the area, the fingerprint data of all 50 fingerprint points in the area can be updated based on the latest fingerprint signals of these 5 automatically identified fingerprint points. The first and second cases of the present invention can serve the third case, making the fingerprint map update more comprehensive and accurate.

[0057] It should be noted that, in practical applications, the range of the preset threshold of the present invention can be determined according to the positioning accuracy. Different users may have different positioning accuracy requirements, and their threshold ranges can take different values. For example, when the difference of the wifi fingerprint signal is greater than 1%, 5%, 10%, etc. of the fingerprint signal before the update, real-time update can be performed.

[0058] To summarize, in order to solve the problem that fingerprint maps for indoor navigation have time-varying characteristics and their accuracy degrades over time, the present invention adopts inertial sensors to perceive and identify indoor environmental characteristics in real time, and accurately locates the positions of environmental landmarks based on map matching technology. Finally, a fingerprint map update module is used to update the indoor fingerprint map in real time, thereby ensuring the "freshness" of the fingerprint map and achieving the reliability and long-term stability of the accuracy of the indoor fingerprint map.

[0059] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for constructing and updating a wifi fingerprint map based on indoor environment characteristics, characterized in that: include: The sensor-based feature landmark recognition module is used to sense and identify indoor environment landmarks by tracking the motion state of moving targets in real time through sensors; An environmental landmark location positioning module based on map matching is used to match the indoor environmental landmark to the constructed indoor electronic map of the building through a map matching algorithm to obtain the location coordinates of the indoor environmental landmark; The wifi fingerprint map construction and update module is used to construct an initial wifi fingerprint map, determine the relationship between the indoor environment landmark and the fingerprint reference point according to the location coordinates, and then update the wifi fingerprint map according to the new wifi fingerprint signal of the indoor environment landmark.

2. The device for constructing and updating a wifi fingerprint map based on indoor environment characteristics according to claim 1 is characterized in that: The sensor includes one or more of an inertial sensor, a visual sensor, a barometer, and a magnetic sensor, and the inertial sensor includes a gyroscope and an accelerometer; And / or, the indoor environment landmarks include corridors, corridor turning points, door turning points, elevator shafts, and stairwells.

3. According to claim 2, a device for constructing and updating a wifi fingerprint map based on indoor environment characteristics, characterized in that: The sensor is the inertial sensor; the feature landmark recognition module uses the angle changes sensed by the gyroscope to identify the corridor turning point, door turning point and corridor in the indoor environment landmark, and uses the acceleration changes sensed by the accelerometer to identify the elevator shaft and stairwell in the indoor environment landmark.

4. According to claim 1, a device for constructing and updating a wifi fingerprint map based on indoor environment characteristics, characterized in that: The road network of the indoor electronic map of the building is composed of corridors and environmental feature landmarks, the corridors constitute the roads in the road network of the indoor electronic map, and the environmental feature landmarks constitute the link nodes between road segments in the road network; The environmental feature landmarks include corridor turning points, door turning points, elevator shafts, and stairwells.

5. According to claim 1, a device for constructing and updating a wifi fingerprint map based on indoor environment characteristics, characterized in that: The sensor is from a mobile terminal device carried by the mobile target, and the new wifi fingerprint signal is collected by the mobile terminal device carried by the mobile target.

6. The device for constructing and updating a wifi fingerprint map based on indoor environment characteristics according to claim 5, characterized in that: The wifi fingerprint map includes fingerprint reference points and their corresponding wifi fingerprint signals; When the difference between the new WiFi fingerprint signal of the indoor environment landmark and the fingerprint signal before the update exceeds a preset threshold, the new WiFi fingerprint signal is used as the WiFi fingerprint signal after the corresponding fingerprint reference point is updated.

7. The device for constructing and updating a wifi fingerprint map based on indoor environment characteristics according to claim 6, characterized in that: The relationship between the indoor environment landmark and the fingerprint reference point includes three situations. The first situation is: the indoor environment landmark coincides with the fingerprint reference point. Then, when the difference between the new wifi fingerprint signal of the indoor environment landmark and the wifi fingerprint signal before the update is greater than a preset threshold, the new wifi fingerprint signal is directly used as the updated wifi fingerprint signal of the corresponding fingerprint reference point; The second case is: if the indoor environment landmark is not a fingerprint reference point, the wifi fingerprint signal of the indoor environment landmark is directly inserted into the wifi fingerprint map as a new fingerprint reference point; The third case is: based on the wifi fingerprint signals before and after the update of several fingerprint reference points in the area, the change error of the wifi fingerprint signal is obtained, and the signal fingerprint of all fingerprint reference points in the area is updated; wherein, the new wifi fingerprint signal of the fingerprint reference point is as shown in formula (1), and the old wifi fingerprint signal is as shown in formula (2). According to the error between the new and old fingerprint signals, an error model is constructed, such as formula (3). Based on the error model, when When it is greater than the preset threshold, Update the signal fingerprints of all fingerprint reference points in the fingerprint map area in real time; in, represents the new wifi fingerprint signal of the i-th fingerprint reference point in the fingerprint map, Indicates the AP corresponding to the i-th new WiFi fingerprint signal j Signal strength RSS; represents the old fingerprint signal of the i-th fingerprint reference point in the fingerprint map, Indicates the AP corresponding to the i-th old fingerprint signal j signal strength RSS; i, j and n are natural numbers, n represents the total number of APs at the i-th fingerprint reference point, and j represents the j-th AP.

8. A method for constructing and updating a wifi fingerprint map based on indoor environment characteristics, characterized in that: First, an indoor electronic map of the building and a corresponding initial wifi fingerprint map are constructed. Then, based on the movement of the mobile target in the building, the indoor environmental landmarks of the mobile target are acquired in real time through sensors. The indoor environmental landmarks are matched to the indoor electronic map of the building through a map matching algorithm to obtain the position coordinates of the indoor environmental landmarks. The relationship between the indoor environmental landmarks and the fingerprint reference points is first determined based on the position coordinates, and then the wifi fingerprint map is updated based on the new wifi fingerprint signal of the indoor environmental landmark.

9. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed by a processor, the wifi fingerprint map construction and update method as claimed in claim 8 is implemented.

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