CN105043387A - Personal indoor positioning system based on inertial navigation aiding geomagnetism - Google Patents

Abstract

The invention relates to a personal indoor positioning system based on inertial navigation assisted geomagnetism. By using the difference of the earth's magnetic field at different points, a smart phone based on the Android platform can realize a personal indoor positioning system that does not depend on external devices by selecting a suitable geomagnetic matching algorithm. Positioning, using inertial navigation technology to obtain the relative position of the mobile individual, and then perform a local search and match the best magnetic field point through the MSD geomagnetic positioning algorithm to obtain more accurate location parameters of the mobile individual, thereby realizing the indoor positioning function of the mobile phone. The present invention effectively improves the matching efficiency of geomagnetic information through the combination positioning method of inertial navigation and assisted geomagnetism, and can obtain higher indoor positioning accuracy. Positioning, easy to use, low cost and easy to promote.

Description

Personal Indoor Positioning System Based on Inertial Navigation Aided Geomagnetism

technical field

The patent of the present invention relates to the field of mobile phone indoor positioning, in particular to a personal indoor positioning system based on inertial navigation-assisted geomagnetism.

Background technique

With the rapid development of science and technology, research on the direction of mobile positioning technology has made great progress in recent years, including GPS indoor positioning, optical tracking positioning, Bluetooth positioning, Wifi indoor positioning, Zigbee indoor positioning, etc. Including GoogleMap, Gaode map, GoogleMap, deer hunting, etc., but these positioning methods require additional corresponding equipment, such as GPS positioning requires satellites, Wifi positioning needs to set up enough Wifi nodes, and Zigbee indoor positioning requires at least three indoor positioning. The above Zigbee nodes constitute a wireless sensor module. However, the above-mentioned positioning method needs to build complex peripheral hardware infrastructure and hardware auxiliary equipment, and the cost is very high, which is not conducive to widespread use.

Contents of the invention

The technical problem to be solved by the present invention is to provide a personal indoor positioning system based on inertial navigation assisted geomagnetism, which does not need to build complex peripheral hardware infrastructure, nor does it need to change the structure of smart phones, and only relies on ordinary smart phones It can obtain better indoor positioning accuracy, and can greatly reduce the expensive cost of additional hardware auxiliary equipment. It is safe, reliable, simple, convenient, and economical for users to use.

In order to solve the problems of the technologies described above, the present invention adopts the following technical solutions:

A personal indoor positioning system based on inertial navigation-assisted geomagnetism, which is arranged on a mobile carrier; it is characterized in that: it mainly includes a smart phone based on the Android platform, and the smart phone has a built-in gyroscope, an accelerometer, and a magnetometer; The gyroscope, accelerometer, and magnetometer respectively obtain the rotation angle, displacement, and azimuth of the carrier, and then construct the internal geomagnetic reference map of the mobile phone by measuring the geomagnetic information in the area where the carrier is located; The technology performs relative positioning to obtain the relative position of the carrier in three-dimensional space, and then matches the best location information of the mobile carrier through the MSD geomagnetic matching algorithm.

In the above technical solution, the positioning work of the personal indoor positioning system based on inertial navigation assisted geomagnetism includes the following steps:

Step S1: Use the built-in magnetometer of the mobile phone to scan the geomagnetic data of the area where the carrier is located, obtain the geomagnetic reference map information of the area and store it in the mobile phone, construct the internal geomagnetic reference map of the mobile phone, and draw a flat map of the mobile phone in proportion to the actual scene;

Step S2: The mobile carrier starts to move. When the carrier moves into the indoor positioning environment, the relative position of the carrier is obtained from the positioning of the inertial navigation system, and a new local geomagnetic reference map is searched from the geomagnetic reference map based on the relative position;

Step S3: The built-in magnetometer of the mobile phone measures the magnetic vector at the position of the carrier in real time; and converts the magnetic vector from a three-dimensional quantity to a two-dimensional quantity;

Step S4: The mobile phone uses the MSD geomagnetic matching algorithm to match the measured and transformed magnetic vector with the local geomagnetic reference map. The data processed by the geomagnetic matching algorithm is stored in the smart phone, and then the location of the carrier is displayed on the flat map of the mobile phone, thereby Realize the real-time display of the position of the carrier by the smart phone.

In the above technical solution, before step S1, the smart phone needs to acquire data, mainly including data acquisition of magnetometer, gyroscope and accelerometer.

In the above technical solution, in step S2, the relationship between the relative position and the built-in accelerometer of the mobile phone is as follows:

${\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; \&Integral;</span>}_{{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}^{{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}$

$\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; =</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; v</span>}}}_{\mathrm{<span\; class="notranslate">\; m</span>}}\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; \&Integral;</span>}_{{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}^{{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}}{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; t</span>}$

Among them, v ₀ and v _m represent the linear velocity of the mobile phone at time t ₀ and t _m respectively, a is the acceleration in one direction of the mobile phone, is the average speed from t ₀ to t _m , and Δs is the relative displacement of the mobile phone.

In the above technical solution, in step S3, the relationship between the magnitude and direction of the magnetic field magnetic vector measured by the magnetometer is as follows:

M(r,t)=M _m (r,t)+M _c (r)+M _d (r,t)

In the formula, M represents the total strength of the magnetic field, M _m represents the main geomagnetic field, M _c represents the crustal geomagnetic field, M _d represents the disturbing geomagnetic field; r represents the position of the carrier, and t represents the time;

In the process of converting the magnetic vector from a three-dimensional quantity to a two-dimensional quantity: M, H, The relationship between the four elements of φ and the projection Mx, My, and Mz of M on the three axes of the earth coordinate system is as follows:

$\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; =</span>\sqrt{{\mathrm{<span\; class="notranslate">\; Mx</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; My</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; Mz</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}$

$\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; =</span>\sqrt{{\mathrm{<span\; class="notranslate">\; Mx</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; My</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}$

$\mathrm{<span\; class="notranslate">\; \&phi;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; r</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; z</span>}}{\sqrt{{\mathrm{<span\; class="notranslate">\; Mx</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; My</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; )</span>$

In the formula, the total strength of the magnetic field is represented by M, which is projected to the northeast plane to obtain H, which is called the horizontal strength; project H to the east-west axis to obtain the east-west field strength Mx; similarly, project H to the north-south axis, Get the north-south field strength My; its Indicates magnetic declination, φ indicates magnetic inclination.

In the above technical solution, when the measured magnetic vector is matched with the local geomagnetic reference map in step S4, the absolute position is obtained by using the geomagnetic matching algorithm mean square deviation MSD, and the geomagnetic matching mean square deviation MSD acquisition relationship is as follows:

$\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; N</span>}}\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; N</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; u</span>}\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}$

D(u,v) in the above formula is the correlation function of geomagnetic matching, N _uv+i represents the feature quantity on the position (u,v+i) of the reference database, m _i represents the i-th feature quantity measured in real time, N Indicates the total number of points for the related data.

Therefore, the present invention is different from traditional indoor positioning methods, does not need to build complex peripheral hardware infrastructure, and can only use inertial navigation to assist MSD (MeanSquareDeviation ) geomagnetic positioning algorithm and the built-in sensor device of the mobile phone can achieve a higher precision positioning effect. That is to say, users only need an Android smart phone with a built-in sensor device, and use the inherent geomagnetic field information provided by the earth to realize indoor positioning. It is safe and reliable for users to use, simple and convenient, economical and convenient. Further, the present invention uses inertial navigation technology to assist the MSD geomagnetic positioning algorithm, which reduces the matching range of the geomagnetic reference map, reduces the calculation amount of geomagnetic matching, and can obtain better indoor positioning accuracy. This method is suitable for large shopping malls, convention centers and For indoor positioning of large underground parking garages, etc., the accuracy can reach 1.0M to 2.0M, and its commercial market value is huge.

Description of drawings

Fig. 1 is the schematic diagram of the personal indoor positioning system based on inertial navigation assisted geomagnetism of the present invention;

Fig. 2 is a block diagram of the geomagnetic matching positioning system involved in the present invention;

Fig. 3 is the positioning flow chart of the inertial navigation aided MSD algorithm of the present invention;

Fig. 4 is a relationship diagram of geomagnetic physical quantities involved in the present invention.

Detailed ways

In order to further illustrate the technical solution of the present invention, the present invention is described in detail with reference to accompanying drawings 1-4.

The personal indoor positioning system based on inertial navigation assisted geomagnetism that the present invention relates to is used for the real-time positioning of the carrier when it moves indoors, including an Android smart phone (with a high-speed multi-core or single-core CPU processor) arranged on the mobile carrier, The mobile carrier is a mobile individual capable of carrying an Android smart phone, and can be moved autonomously or passively (if the mobile carrier is a person or a movable object without a smart device, the mobile phone is controlled by the person or the movable object to move, if the mobile carrier is mobile smart body, the mobile phone is controlled by the smart body and can communicate with the mobile phone); the smart phone is equipped with a gyroscope, an acceleration sensor, and a geomagnetic sensor, wherein the gyroscope (Gyroscope, GYRO-Sensor) is also called a ground sensor, The traditional structure is that there is a gyro inside. The working principle of the three-axis gyroscope is to perceive the angle between the vertical axis of the gyro rotor and the equipment in the three-dimensional coordinate system, and calculate the angular velocity, and judge the object in three-dimensional space through the angle and angular velocity. state of motion. The three-axis gyroscope can sense six directions of up, down, left, right, front, and back at the same time (the synthetic direction can also be decomposed into three-axis coordinates), and finally can judge the movement trajectory and acceleration of the device; the acceleration sensor (Accelerometer, G-Sensor) is also called a gravity sensor. It senses the acceleration along the vertical direction of the ground surface by sensing the force of the carrier on a certain axis. In fact, it can sense the acceleration in any direction; the geomagnetic sensor is used to sense the carrier. The strength and direction of the magnetic field can also locate the bearing of the carrier. In fact, the working principle of the magnetometer is similar to that of the compass in many aspects. It can sense the angle between the current carrier and the four directions of east, west, north and south.

In the present invention, all are implemented on Android smart phones. The inertial navigation assisted geomagnetic positioning system of the present invention is mainly divided into a geomagnetic acquisition module, an inertial navigation system, and a geomagnetic positioning matching algorithm module. The geomagnetic acquisition module mainly completes the data reading and preprocessing of the geomagnetic sensor module, scans the geomagnetic data of the region through the high-precision three-axis magnetometer that comes with the mobile phone, obtains the geomagnetic reference map information of the region, and uploads it to the mobile phone; The schematic diagram of the navigation system is shown in Figure 1 (corresponding to Figure 1 for description). It can be seen from Figure 1 that, according to the mobile phone accelerometer and the gyroscope in the mobile phone, the three linear acceleration values and three angular velocity values of the mobile carrier are respectively obtained, and then the The acceleration of the mobile phone is used for coordinate transformation, and the angular velocity of the mobile phone is used for attitude calculation. After Kalman filtering and navigation calculation, the navigation information such as the position, speed, and attitude of the mobile phone and the mobile carrier can be obtained.

The block diagram of the geomagnetic matching and positioning system is shown in Figure 2. It can be seen from Figure 2 that when navigating, the pre-measured geomagnetic information is first stored on the mobile phone to form a digital geomagnetic reference map, and at the same time, the plane map of the mobile phone is drawn in proportion to the actual scene. When the carrier moves to a specific matching area, the magnetic sensor of the mobile phone measures the magnetic field characteristics of the location. After the carrier moves for a period of time, a series of real-time magnetic field characteristic values are measured, referred to as the measurement sequence. Correspondingly match the measurement sequence with the reference image, and find out the position sequence that best matches the measurement sequence in the reference image, and use it as the position estimation information of the carrier.

Figure 3 is a flow chart of inertial navigation-assisted MSD algorithm positioning, which mainly includes the following steps:

Step S1: acquisition of sensor data of the smart phone, mainly including data acquisition of magnetometer, gyroscope and accelerometer.

Step S2: Use the high-precision three-axis magnetometer that comes with the mobile phone to scan the geomagnetic data of the area, obtain the geomagnetic reference map information of the area, and store it in the mobile phone to construct the internal geomagnetic reference map of the mobile phone, and scale it according to the actual scene Draw a flat map of the mobile phone;

Step S3: When the carrier moves into the indoor positioning environment, the relative position of the positioning is obtained by the inertial navigation system, and based on this relative position, a new local geomagnetic reference map can be searched from the geomagnetic reference map;

Step S4: Measure the magnetic vector at the location in real time by the built-in magnetic sensor of the mobile phone. The relationship between the magnitude and direction of the magnetic field measured by the sensor is as follows:

M(r,t)=M _m (r,t)+M _c (r)+M _d (r,t)

In the formula, M represents the total strength of the magnetic field, M _m represents the main geomagnetic field, M _c represents the crustal geomagnetic field, and M _d represents the disturbing geomagnetic field;

Then, the geomagnetic vector is decomposed into the three directions of the earth coordinate system through the attitude calculation. The magnetic field component in the X-axis direction is approximately zero and can be ignored. The geomagnetic vector can be converted from a three-dimensional quantity to a two-dimensional quantity. The relationship diagram of the geomagnetic physical quantity is shown in the figure 4, M, H, The relationship between the four elements of φ and the projections of Mx, My, and Mz on the three axes of M is as follows, and the representation of each physical quantity is shown in Figure 4:

$\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; =</span>\sqrt{{\mathrm{<span\; class="notranslate">\; Mx</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; My</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; Mz</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}$

$\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; =</span>\sqrt{{\mathrm{<span\; class="notranslate">\; Mx</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; My</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}$

$\mathrm{<span\; class="notranslate">\; \&phi;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arctan</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; z</span>}}{\sqrt{{\mathrm{<span\; class="notranslate">\; Mx</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; My</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; )</span>$

In the formula, the total field strength of the magnetic field is represented by M, which is projected to the northeast plane to obtain H, which is called the horizontal strength; project H to the east-west axis to obtain the east-west field strength Mx; similarly, project H to the north-south axis , get the north-south field strength My; where Indicates magnetic declination, φ indicates magnetic inclination;

Step S5: Match the measured magnetic vector with the local geomagnetic reference map, and use the geomagnetic matching algorithm mean square error MSD to obtain the absolute position. The geomagnetic matching mean square error algorithm is as follows:

$\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; N</span>}}\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; N</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; u</span>}\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}$

D(u,v) in the above formula is the correlation function of geomagnetic matching, N _uv+i represents the feature quantity on the position (u,v+i) of the reference database, m _i represents the i-th feature quantity measured in real time, N Indicates the total number of points for the related data.

Step S6: Convert the processed location data to the flat map of the mobile phone, so that the mobile phone user can display his/her own location in real time.

In summary, the present invention uses inertial navigation technology to estimate the position of the mobile individual to obtain an estimated position, then perform a local search and match the best magnetic field point through the MSD geomagnetic positioning algorithm to obtain more accurate location parameters of the mobile individual , so as to realize the indoor positioning function of the mobile phone, which is different from the traditional indoor positioning method and does not need to build complex peripheral hardware infrastructure. It is safe, reliable, simple, convenient, economical and convenient for users to use, and has economic and practical value.

Claims (6)

1. A personal indoor positioning system based on inertial navigation assisted geomagnetism, which is arranged on a mobile carrier; it is characterized in that: mainly comprising a smart phone based on Android platform, said smart phone has built-in gyroscope, accelerometer, magnetometer; The mobile phone obtains the rotation angle, displacement, and azimuth of the carrier through the gyroscope, accelerometer, and magnetometer, and then builds a geomagnetic reference map inside the mobile phone by measuring the geomagnetic information in the area where the carrier is located; In the process, inertial navigation technology is used for relative positioning to obtain the relative position of the carrier in three-dimensional space, and then the MSD geomagnetic matching algorithm is used to match the best location information of the mobile carrier. 2. The personal indoor positioning system based on inertial navigation assisted geomagnetism according to claim 1, characterized in that: comprising the steps of: Step S1: Use the built-in magnetometer of the mobile phone to scan the geomagnetic data of the area where the carrier is located, obtain the geomagnetic reference map information of the area and store it in the mobile phone, construct the internal geomagnetic reference map of the mobile phone, and draw a flat map of the mobile phone in proportion to the actual scene; Step S2: The mobile carrier starts to move. When the carrier moves into the indoor positioning environment, the relative position of the carrier is obtained from the positioning of the inertial navigation system, and a new local geomagnetic reference map is searched from the geomagnetic reference map based on the relative position; Step S3: The built-in magnetometer of the mobile phone measures the magnetic vector of the position of the carrier in real time; and converts the magnetic vector from a three-dimensional quantity to a two-dimensional quantity; Step S4: The mobile phone uses the MSD geomagnetic matching algorithm to match the measured and transformed magnetic vector with the local geomagnetic reference map. The data processed by the geomagnetic matching algorithm is stored in the smart phone, and then the location of the carrier is displayed on the flat map of the mobile phone, thereby Realize the real-time display of the position of the carrier by the smart phone. 3. The personal indoor positioning system based on inertial navigation assisted geomagnetism according to claim 2, characterized in that: before step S1, the smart phone needs to acquire data, mainly including magnetometer, gyroscope and accelerometer data acquisition. 4. The personal indoor positioning system based on inertial navigation assisted geomagnetism according to claim 2, characterized in that: in step S2, the relationship between the relative position and the built-in accelerometer of the mobile phone is as follows: ${\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; \&Integral;</span>}_{{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}^{{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}$ $\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; =</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; v</span>}}}_{\mathrm{<span\; class="notranslate">\; m</span>}}\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; \&Integral;</span>}_{{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}^{{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}}{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; t</span>}$ Among them, v ₀ and v _m represent the linear velocity of the mobile phone at time t ₀ and t _m respectively, a is the acceleration in one direction of the mobile phone, is the average speed from t ₀ to t _m , and Δs is the relative displacement of the mobile phone. 5. The personal indoor positioning system based on inertial navigation assisted geomagnetism according to claim 2, characterized in that: in step S3, the relationship between the magnitude and direction of the magnetic field magnetic vector recorded by the magnetometer is as follows: M(r,t)=M _m (r,t)+M _c (r)+M _d (r,t) In the formula, M represents the total strength of the magnetic field, M _m represents the main geomagnetic field, M _c represents the crustal geomagnetic field, M _d represents the disturbing geomagnetic field; r represents the position of the carrier, and t represents the time; In the process of converting the magnetic vector from a three-dimensional quantity to a two-dimensional quantity: M, H, The relationship between the four elements of φ and the projection Mx, My, and Mz of M on the three axes of the earth coordinate system is as follows: $\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; =</span>\sqrt{{\mathrm{<span\; class="notranslate">\; Mx</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; My</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; Mz</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}$ $\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; =</span>\sqrt{{\mathrm{<span\; class="notranslate">\; Mx</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; My</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}$ $\mathrm{<span\; class="notranslate">\; \&phi;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; r</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; z</span>}}{\sqrt{{\mathrm{<span\; class="notranslate">\; Mx</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; My</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}}<span\; class="notranslate">\; )</span>$ In the formula, the total strength of the magnetic field is represented by M, which is projected to the northeast plane to obtain H, which is called the horizontal strength; project H to the east-west axis to obtain the east-west field strength Mx; similarly, project H to the north-south axis, Get the north-south field strength My; where Indicates magnetic declination, φ indicates magnetic inclination. 6. The personal indoor positioning system based on inertial navigation assisted geomagnetism according to claim 2, characterized in that: when the measured magnetic vector is matched with the local geomagnetic reference map in step S4, the geomagnetic matching algorithm mean square error MSD is used to obtain the absolute position, its geomagnetic matching mean square deviation MSD acquisition relationship is as follows: $\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; N</span>}}\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; N</span>}}{<span\; class="notranslate">\; \&Sigma;</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; u</span>}\mathrm{<span\; class="notranslate">\; v</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; m</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}$ D(u,v) in the above formula is the correlation function of geomagnetic matching, N _uv+i represents the feature quantity on the position (u,v+i) of the reference database, m _i represents the i-th feature quantity measured in real time, N Indicates the total number of points for the related data.