A vehicle-mounted Bluetooth positioning method

Abstract

The invention discloses a vehicle-mounted Bluetooth positioning method, comprising S1, initially positioning the current vehicle body coordinate position based on a vehicle-mounted navigation system; S2, a Bluetooth transmitting terminal located on the vehicle body transmits multiple groups of RSSI signals to multiple nearby base stations; S3, normalizing the RSSI response signal according to the received RSSI response signal, and calculating the distance di between the Bluetooth transmitting terminal and different base stations, where di is the distance between the Bluetooth transmitting terminal and the i-th base station; S4, correcting the current vehicle body coordinate according to the distance di between the transmitting terminal and multiple base stations; S5, sending the corrected vehicle body coordinate data to a cloud server, and the cloud server encrypting the vehicle body coordinate data to form an encrypted data packet and a decrypted data packet; S6, a remote client uses the decrypted data packet to decrypt the encrypted data packet, and combines the data obtained after decryption to obtain the current vehicle body coordinate information.

Description

Technical Field

[0001] The invention belongs to the technical field of Bluetooth-assisted positioning, and in particular relates to a vehicle-mounted Bluetooth positioning method. Background Art

[0002] Car navigation is also called "car navigation". "Car navigation" is a navigation device in the car. The general car navigation is carried out by using the car GPS (Global Positioning System) with the electronic map. It can conveniently and accurately tell the driver the shortest or fastest route to the destination, and is a good helper for the driver. Car navigation is not only a navigation function, but also includes audio and video playback, 3G Internet access, radio, games, e-book reading, digital TV, etc.

[0003] However, the accuracy of existing car navigation systems is not high and cannot accurately locate the vehicle, which often leads to navigation errors. At the same time, existing in-vehicle navigation systems are directly connected to the network with remote clients, such as mobile phones, that is, the client can remotely monitor the vehicle's operating position at any time, but it only needs to perform a simple verification, which can be easily known by others to obtain the customer's real-time location, resulting in privacy leakage. Summary of the invention

[0004] The purpose of the present invention is to provide a vehicle-mounted Bluetooth positioning method to solve or improve the above-mentioned problems in view of the above-mentioned deficiencies in the prior art.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A vehicle-mounted Bluetooth positioning method comprises the following steps:

[0007] S1, initially locating the current vehicle coordinate position based on the vehicle navigation system;

[0008] S2, the Bluetooth transmitting terminal located on the vehicle body transmits multiple groups of RSSI signals to multiple base stations nearby;

[0009] S3, according to the received RSSI response signal, the RSSI response signal is normalized, and the distance di between the Bluetooth transmitting terminal and different base stations is calculated, where di is the distance between the Bluetooth transmitting terminal and the i-th base station;

[0010] S4, correcting the current vehicle coordinates according to the distances di between the transmitting terminal and the multiple base stations;

[0011] S5, sending the corrected vehicle body coordinate data to the cloud server, and the cloud server encrypts the vehicle body coordinate data to form an encrypted data packet and a decrypted data packet;

[0012] S6. The remote client uses the decrypted data packet to decrypt the encrypted data packet, and combines the data obtained after decryption to obtain the current vehicle body coordinate information.

[0013] A further technical solution of the method is that in step S3, according to the received RSSI response signal, the RSSI response signal is normalized to calculate the distance di between the Bluetooth transmitting terminal and different base stations, where di is the distance between the Bluetooth transmitting terminal and the i-th base station, including:

[0014] Calculate the distance d between the Bluetooth transmitting terminal and the base station:

[0015]

[0016] Among them, RSSI is the signal strength, A is the signal strength when the signal transmitter and receiver are 1 meter apart, and n is the environmental attenuation factor;

[0017] Calculate the environmental attenuation factor based on the calculated multiple distance values ​​and signal strength:

[0018]

[0019] Wherein, d1 and d2 are the distances between the Bluetooth transmitting terminal and the base station calculated at different positions, and RSSI1 and RSSI2 are the signal strengths corresponding to the distances d1 and d2;

[0020] According to the calculated environmental attenuation factor, we can get:

[0021] A = abs(RSSI)-10×n×lg d.

[0022] A further technical solution of the method is that in step S4, the current vehicle coordinates are corrected according to the distance Di between the transmitting terminal and the multiple base stations, including:

[0023] The observation equation is:

[0024] V i =[(X i -X) 2 +(Y i -Y) 2 ] 1 / 2 -d i

[0025] Among them, V i is the error term, X i , Y i are the coordinates of other points;

[0026] Taylor expansion of the observation equation:

[0027]

[0028]

[0029]

[0030] Among them, l, m are errors, X0, Y0 are the horizontal and vertical coordinates of the current vehicle body coordinates, δ x and δ y is the weight error of the horizontal and vertical coordinates;

[0031] Simplifying the above formula, we get the matrix:

[0032] V=AX+L

[0033] You can get:

[0034] X=-(A T A) -1 (A T L)

[0035] Among them, the matrix V is the column matrix of Vi, X=(δ x , δ y ) T ;

[0036] The corrected vehicle coordinates (X, Y) are calculated as follows:

[0037] X=X0+l

[0038] Y=Y0+m.

[0039] A further technical solution of the method is that in step S5, the corrected vehicle body coordinate data is sent to a cloud server, and the cloud server encrypts the vehicle body coordinate data including:

[0040] Generate random data X0, l, Y0, m according to the corrected vehicle body coordinates (X0+l, Y0+m);

[0041] Send a request to the cloud server to divide the first address IP1, the second address IP2, the third address IP3 and the fourth address IP4;

[0042] The randomly ordered four data X0, l, Y0, and m are stored in the first address IP1, the second address IP2, the third address IP3, and the fourth address IP4 respectively;

[0043] In response to the server, four random numbers corresponding to the four IP addresses are generated, including a first key W1, a second key W2, a third key W3 and a fourth key W4;

[0044] The first key W1 contains data information of the first address IP1;

[0045] The second key W2 contains data information of the second address IP2;

[0046] The third key W3 contains data information of the third address IP3;

[0047] The fourth key W4 includes data information of the fourth address IP4.

[0048] A further technical solution of the method is that the encrypted data packet in step S5 includes the corrected vehicle body coordinates (X0+1, Y0+m);

[0049] The decrypted data packet includes a first key W1, a second key W2, a third key W3, a fourth key W4 and a decryption sequence.

[0050] A further technical solution of the method is that the decryption sequence is a decryption code and a combination sequence of four random data X0, l, Y0, and m.

[0051] A further technical solution of the method is that in step S6, the remote client uses the decrypted data packet to decrypt the encrypted data packet, including:

[0052] T1, obtain the decryption codes G1, G2, G3, G4 and the combination sequence (1, 3, 2, 4) in the decryption sequence, where 1 corresponds to the initial horizontal coordinate of the vehicle body coordinates, 3 corresponds to the initial vertical coordinate of the vehicle body coordinates, 2 corresponds to the horizontal coordinate correction value, and 4 corresponds to the vertical coordinate correction value;

[0053] T2, using the decryption code G1 as the first decryption sequence, obtaining the first key W1 through the decryption code G1, and the first key W1 is used to decrypt to obtain the first address IP1, so as to obtain the data X0;

[0054] T3, using the decryption code G2 as the second decryption sequence, obtaining the second key W2 through the decryption code G2, and the second key W2 is used to decrypt to obtain the second address IP2 to obtain the data Y0;

[0055] T4, using the decryption code G3 as the third decryption sequence, obtaining the third key W3 through the decryption code G3, and the third key W3 is used to decrypt to obtain the third address IP3, so as to obtain the data l;

[0056] T5, using the decryption code G4 as the fourth decryption sequence, obtaining the fourth key W4 through the decryption code G4, and the fourth key W4 is used to decrypt to obtain the fourth address IP4 to obtain the data m;

[0057] T6. Use the combination sequence (1, 3, 2, 4) to combine X0, l, Y0, and m obtained in sequence to obtain the corrected vehicle body coordinates (X0+l, Y0+m).

[0058] The vehicle-mounted Bluetooth positioning method provided by the present invention has the following beneficial effects:

[0059] The present invention adopts vehicle-mounted navigation for preliminary positioning, cooperates with a Bluetooth transmitter and multiple base stations, and adopts the least square method to realize the correction of the preliminary positioning of the vehicle body to obtain more accurate vehicle body position coordinates, and adopts Bluetooth-assisted positioning, which has low power consumption, simple method, low cost and high practicality.

[0060] The present invention encrypts the vehicle body coordinate data, so that even if the remote client is cracked by others, the decryption sequence cannot be known, and the specific position coordinates of the vehicle body cannot be obtained, thereby enhancing the security of customer information. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 The figure is a flow chart of the vehicle-mounted Bluetooth positioning method. DETAILED DESCRIPTION

[0062] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0063] According to one embodiment of the present application, referring to Figure 1 The vehicle-mounted Bluetooth positioning method of this solution includes the following steps:

[0064] Step S1, initially locating the current vehicle coordinate position based on the vehicle navigation system;

[0065] Step S2, the Bluetooth transmitting terminal located on the vehicle body transmits multiple groups of RSSI signals to multiple base stations nearby;

[0066] Step S3, according to the received RSSI response signal, the RSSI response signal is normalized, and the distance di between the Bluetooth transmitting terminal and different base stations is calculated, where di is the distance between the Bluetooth transmitting terminal and the i-th base station;

[0067] Step S4, correcting the current vehicle coordinates according to the distances di between the transmitting terminal and the multiple base stations;

[0068] Step S5, sending the corrected vehicle body coordinate data to the cloud server, and the cloud server encrypts the vehicle body coordinate data to form an encrypted data packet and a decrypted data packet;

[0069] Step S6: The remote client uses the decrypted data packet to decrypt the encrypted data packet, and combines the data obtained after decryption to obtain the current vehicle body coordinate information.

[0070] The following is a detailed description of each of the above steps:

[0071] Step S1: Preliminary positioning of the current vehicle coordinate position based on the vehicle navigation system. Since the vehicle navigation is affected by many factors such as the environment, signal strength, and interference between signals, its positioning accuracy cannot meet the positioning requirements. Therefore, this step uses the vehicle's own navigation system for preliminary positioning.

[0072] Step S2, the Bluetooth transmitting terminal located on the vehicle body transmits multiple groups of RSSI signals to multiple nearby base stations; in this step, the preferred number of base stations is 5, and the locations of the 5 base stations are different.

[0073] Step S3, according to the received RSSI response signal, the RSSI response signal is normalized, and the distance di between the Bluetooth transmitting terminal and different base stations is calculated, where di is the distance between the Bluetooth transmitting terminal and the i-th base station, including:

[0074] Calculate the distance d between the Bluetooth transmitting terminal and the base station:

[0075]

[0076] Among them, RSSI is the signal strength, A is the signal strength when the signal transmitter and receiver are 1 meter apart, and n is the environmental attenuation factor;

[0077] Calculate the environmental attenuation factor based on the calculated multiple distance values ​​and signal strength:

[0078]

[0079] Wherein, d1 and d2 are the distances between the Bluetooth transmitting terminal and the base station calculated at different positions, and RSSI1 and RSSI2 are the signal strengths corresponding to the distances d1 and d2;

[0080] According to the calculated environmental attenuation factor, we can get:

[0081] A = abs(RSSI)-10×n×lg d.

[0082] That is, step S3 calculates the distances between the current vehicle body and the five base stations respectively.

[0083] Step S4, correcting the current vehicle coordinates according to the distance Di between the transmitting terminal and the multiple base stations, includes:

[0084] The observation equation is:

[0085] Vi =[(X i -X) 2 +(Y i -Y) 2 ] 1 / 2 -d i

[0086] Among them, V i is the error term, X i , Y i are the coordinates of other points;

[0087] Taylor expansion of the observation equation:

[0088]

[0089]

[0090]

[0091] Among them, l, m are errors, X0, Y0 are the horizontal and vertical coordinates of the current vehicle body coordinates, δ x and δ y is the weight error of the horizontal and vertical coordinates;

[0092] Simplifying the above formula, we get the matrix:

[0093] V=AX+L

[0094] You can get:

[0095] X=-(A T A) -1 (A T L)

[0096] Among them, the matrix V is the column matrix of Vi, X=(δ x , δ y ) T ;

[0097] The corrected vehicle coordinates (X, Y) are calculated as follows:

[0098] X=X0+l

[0099] Y=Y0+m.

[0100] The corrected body coordinates (X0+1, Y0+m) of the current body are calculated in this way.

[0101] Step S5, sending the corrected vehicle coordinate data to the cloud server, and the cloud server encrypting the vehicle coordinate data includes:

[0102] Generate random data X0, l, Y0, m according to the corrected vehicle body coordinates (X0+l, Y0+m);

[0103] Send a request to the cloud server to divide the first address IP1, the second address IP2, the third address IP3 and the fourth address IP4;

[0104] The randomly ordered four data X0, l, Y0, and m are stored in the first address IP1, the second address IP2, the third address IP3, and the fourth address IP4 respectively;

[0105] In response to the server, four random numbers corresponding to the four IP addresses are generated, including a first key W1, a second key W2, a third key W3 and a fourth key W4;

[0106] The first key W1 contains data information of the first address IP1;

[0107] The second key W2 contains data information of the second address IP2;

[0108] The third key W3 contains data information of the third address IP3;

[0109] The fourth key W4 includes data information of the fourth address IP4.

[0110] Encrypted data packet, including the corrected vehicle coordinates (X0+l, Y0+m);

[0111] The decrypted data packet includes a first key W1, a second key W2, a third key W3, a fourth key W4 and a decryption sequence.

[0112] The first key W1, the second key W2, the third key W3, and the fourth key W4 are the decryption order, and each key corresponds to random data. For ease of understanding, this embodiment uses the first key W1 to decrypt to obtain data X0; uses the second key W2 to decrypt to obtain data Y0; uses the third key W3 to decrypt to obtain data l; and uses the fourth key W4 to decrypt to obtain data m.

[0113] In specific applications, when the four data obtained by decrypting the first key W1, the second key W2, the third key W3, and the fourth key W4 are random data, their positions in the corrected coordinates cannot be known, that is, the specific coordinate positions cannot be obtained based on the four random data. In this case, in order to further increase the encryption level, a combined sequence is used to combine the four data. In this way, complete positioning information can be obtained to avoid information leakage.

[0114] The decryption sequence is the decryption code and combination sequence of the four random data X0, l, Y0, and m.

[0115] Step S6: the remote client uses the decrypted data packet to decrypt the encrypted data packet, including:

[0116] Step T1, obtaining the decryption codes G1, G2, G3, G4 and the combination sequence (1, 3, 2, 4) in the decryption sequence; 1 corresponds to the initial horizontal coordinate of the vehicle body coordinates, 3 corresponds to the initial vertical coordinate of the vehicle body coordinates, 2 corresponds to the horizontal coordinate correction value, and 4 corresponds to the vertical coordinate correction value;

[0117] When four random numbers are obtained through post-decryption, the data are combined in the form of corrected coordinates according to the combination sequence to obtain the final positioning coordinates.

[0118] Step T2, using the decryption code G1 as the first decryption sequence, obtaining the first key W1 through the decryption code G1, and the first key W1 is used to decrypt to obtain the first address IP1, so as to obtain the data X0;

[0119] Step T3, using the decryption code G2 as the second decryption sequence, obtaining the second key W2 through the decryption code G2, and the second key W2 is used to decrypt to obtain the second address IP2 to obtain the data Y0;

[0120] Step T4, using the decryption code G3 as the third decryption sequence, obtaining the third key W3 through the decryption code G3, and the third key W3 is used to decrypt to obtain the third address IP3, so as to obtain the data l;

[0121] Step T5, using the decryption code G4 as the fourth decryption sequence, obtaining the fourth key W4 through the decryption code G4, and the fourth key W4 is used to decrypt to obtain the fourth address IP4, so as to obtain the data m;

[0122] Step T6: Combine X0, l, Y0, and m obtained in sequence using the combination sequence (1, 3, 2, 4) to obtain the corrected vehicle body coordinates (X0+l, Y0+m).

[0123] The present invention adopts vehicle-mounted navigation for preliminary positioning, cooperates with a Bluetooth transmitter and multiple base stations, and adopts the least square method to realize the correction of the preliminary positioning of the vehicle body to obtain more accurate vehicle body position coordinates, and adopts Bluetooth-assisted positioning, which has low power consumption, simple method, low cost and high practicality.

[0124] The present invention encrypts the vehicle body coordinate data, so that even if the remote client is cracked by others, the decryption sequence cannot be known, and the specific position coordinates of the vehicle body cannot be obtained, thereby enhancing the security of customer information.

[0125] Although the specific implementation of the invention is described in detail in conjunction with the drawings, it should not be understood as limiting the scope of protection of this patent. Within the scope described in the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

Claims

1. A vehicle-mounted Bluetooth positioning method, characterized in that: The following steps are involved: S1, initially locating the current vehicle coordinate position based on the vehicle navigation system; S2, the Bluetooth transmitting terminal located on the vehicle body transmits multiple groups of RSSI signals to multiple base stations nearby; S3, according to the received RSSI response signal, the RSSI response signal is normalized, and the distance di between the Bluetooth transmitting terminal and different base stations is calculated, where di is the distance between the Bluetooth transmitting terminal and the i-th base station; S4, correcting the current vehicle coordinates according to the distances di between the transmitting terminal and the multiple base stations; S5, sending the corrected vehicle body coordinate data to the cloud server, and the cloud server encrypts the vehicle body coordinate data to form an encrypted data packet and a decrypted data packet; S6, the remote client uses the decrypted data packet to decrypt the encrypted data packet, and combines the data obtained after decryption to obtain the current vehicle body coordinate information; In step S3, the RSSI response signal is normalized according to the received RSSI response signal, and the distance di between the Bluetooth transmitting terminal and different base stations is calculated, where di is the distance between the Bluetooth transmitting terminal and the i-th base station, including: calculating the distance d between the Bluetooth transmitting terminal and the base station: Among them, RSSI is the signal strength, A is the signal strength when the signal transmitter and receiver are 1 meter apart, and n is the environmental attenuation factor; Calculate the environmental attenuation factor based on the calculated multiple distance values ​​and signal strength: Wherein, d1 and d2 are the distances between the Bluetooth transmitting terminal and the base station calculated at different positions, and RSSI1 and RSSI2 are the signal strengths corresponding to the distances d1 and d2; According to the calculated environmental attenuation factor, we can get: A = abs(RSSI)-10×n×lgd; In step S4, the current vehicle coordinates are corrected according to the distances Di between the transmitting terminal and the multiple base stations, including: The observation equation is: V i =[(X i -X) 2 +(Y i -Y) 2 ] 1 / 2 -d i Among them, V i is the error term, X i , Y i are the coordinates of other points; Taylor expansion of the observation equation: Among them, l, m are errors, X0, Y0 are the horizontal and vertical coordinates of the current vehicle body coordinates, δ x and δ y is the weight error of the horizontal and vertical coordinates; Simplifying the above formula, we get the matrix: V=AX+L You can get: X=-(A T A) -1 (A T L) Among them, the matrix V is the column matrix of Vi, X=(δ x , δ y ) T ; The corrected vehicle coordinates (X, Y) are calculated as follows: X=X0+l Y=Y0+m.

2. The vehicle-mounted Bluetooth positioning method according to claim 1, characterized in that: In step S5, the corrected vehicle coordinate data is sent to the cloud server, and the cloud server encrypts the vehicle coordinate data, including: Generate random data X0, l, Y0, m according to the corrected vehicle body coordinates (X0+l, Y0+m); Send a request to the cloud server to divide the first address IP1, the second address IP2, the third address IP3 and the fourth address IP4; The randomly ordered four data X0, l, Y0, and m are stored in the first address IP1, the second address IP2, the third address IP3, and the fourth address IP4 respectively; In response to the server, four random numbers corresponding to the four IP addresses are generated, including a first key W1, a second key W2, a third key W3 and a fourth key W4; The first key W1 contains data information of the first address IP1; The second key W2 contains data information of the second address IP2; The third key W3 contains data information of the third address IP3; The fourth key W4 includes data information of the fourth address IP4.

3. The vehicle-mounted Bluetooth positioning method according to claim 2, characterized in that: The encrypted data packet in step S5 includes the corrected vehicle body coordinates (X0+1, Y0+m); The decrypted data packet includes a first key W1, a second key W2, a third key W3, a fourth key W4 and a decryption sequence.

4. The vehicle-mounted Bluetooth positioning method according to claim 3, characterized in that: The decryption sequence is the decryption code and combination sequence of the four random data X0, l, Y0, and m.

5. The vehicle-mounted Bluetooth positioning method according to claim 4, characterized in that: In step S6, the remote client uses the decrypted data packet to decrypt the encrypted data packet, including: T1, obtain the decryption codes G1, G2, G3, G4 and the combination sequence (1, 3, 2, 4) in the decryption sequence, where 1 corresponds to the initial horizontal coordinate of the vehicle body coordinates, 3 corresponds to the initial vertical coordinate of the vehicle body coordinates, 2 corresponds to the horizontal coordinate correction value, and 4 corresponds to the vertical coordinate correction value; T2, using the decryption code G1 as the first decryption sequence, obtaining the first key W1 through the decryption code G1, and the first key W1 is used to decrypt to obtain the first address IP1, so as to obtain the data X0; T3, using the decryption code G2 as the second decryption sequence, obtaining the second key W2 through the decryption code G2, and the second key W2 is used to decrypt to obtain the second address IP2 to obtain the data Y0; T4, using the decryption code G3 as the third decryption sequence, obtaining the third key W3 through the decryption code G3, and the third key W3 is used to decrypt to obtain the third address IP3, so as to obtain the data l; T5, using the decryption code G4 as the fourth decryption sequence, obtaining the fourth key W4 through the decryption code G4, and the fourth key W4 is used to decrypt to obtain the fourth address IP4 to obtain the data m; T6. Use the combination sequence (1, 3, 2, 4) to combine X0, l, Y0, and m obtained in sequence to obtain the corrected vehicle body coordinates (X0+l, Y0+m).

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