Vehicle positioning system and vehicle positioning method

Abstract

A vehicle positioning system includes: a wireless transceiver unit installed on a street lamp, used to transmit and receive signals, and also used to determine whether the current weather has an impact on the transmission power, and when it is determined that the current weather has an impact on the transmission signal, retransmit the signal after compensating for the transmission power attenuation value; a positioning unit, set on a vehicle, used to receive the signal transmitted by the wireless transceiver unit, and determine the coordinate point of the vehicle based on the signal, thereby achieving positioning that is not easily affected by weather and improving positioning accuracy.

Description

Technical Field

[0001] The present invention relates to the field of positioning technology, and in particular to a vehicle positioning system and a vehicle positioning method. Background Art

[0002] Positioning technology can not only provide various location-based services, such as information query of nearby stores, gas stations, and restaurants, but also be used for emergency rescue, vehicle dispatch, etc. At present, automobile positioning and navigation mainly rely on satellite positioning systems, which are easily affected by weather and lead to inaccurate positioning or inaccurate positioning, which brings troubles to users. Summary of the invention

[0003] In view of this, it is necessary to provide a vehicle positioning system that is not easily affected by weather and improves positioning accuracy.

[0004] A vehicle positioning system provided by one embodiment of the present invention is characterized by comprising:

[0005] The wireless transceiver unit is installed on the street lamp and is used to transmit and receive signals. It is also used to determine whether the current weather has an impact on the transmission power. If it is determined that the current weather has an impact on the transmission signal, it will retransmit the signal after compensating for the transmission power attenuation value.

[0006] The positioning unit is arranged on the vehicle and is used for receiving the signal transmitted by the wireless transceiver unit and determining the coordinate point of the vehicle according to the signal.

[0007] Preferably, the number of the wireless transceiver units is at least two, and each wireless transceiver unit is further used to preset a standard transmission power value for receiving an adjacent wireless transceiver unit;

[0008] When a wireless transceiver unit receives a signal transmitted by an adjacent wireless transceiver unit, it determines whether the power of the signal is within a preset range. If the power of the signal is not within the preset range, the current weather has an impact on the transmission power.

[0009] Preferably, if the current weather has an impact on the transmission power, the wireless transceiver unit calculates the difference between the power of the signal and the standard transmission power value, and uses the difference as a compensation value for the transmission power of the wireless transceiver unit before retransmitting the signal.

[0010] Preferably, the positioning unit is further used for:

[0011] determining whether a process of determining the coordinate point of the vehicle causes a delay;

[0012] If a delay is caused, a compensation value of the vehicle position is calculated according to the speed of the vehicle and the delay time to determine the final coordinate point.

[0013] Preferably, when the vehicle is not moving, the positioning unit determines that the process of determining the coordinate point of the vehicle does not cause a delay;

[0014] When the vehicle is traveling, the positioning unit determines that a process of determining a coordinate point of the vehicle causes a delay.

[0015] A vehicle positioning method provided in one embodiment of the present invention is applied to a vehicle positioning system, wherein the vehicle positioning system includes a wireless transceiver unit installed on a street lamp and a positioning unit provided on a vehicle, and the method includes:

[0016] The wireless transceiver unit transmits a signal;

[0017] Determine whether the current weather has an impact on the transmission power;

[0018] If the current weather has an impact on the transmit power, compensate for the transmit power attenuation value;

[0019] Retransmit the signal;

[0020] The positioning unit receives the signal;

[0021] The coordinate point of the vehicle is determined based on the signal.

[0022] Preferably, the number of the wireless transceiver units is at least two, and the step of determining whether the current weather has an impact on the transmission power specifically includes:

[0023] Presetting a standard transmission power value for each wireless transceiver unit to receive an adjacent wireless transceiver unit;

[0024] When a wireless transceiver unit receives a signal transmitted by an adjacent wireless transceiver unit, the difference between the power of the signal and the standard transmission power value is calculated;

[0025] Determining whether the power of the signal is within a preset range;

[0026] If the power of the signal is not within the preset range, the current weather has an impact on the transmission power.

[0027] Preferably, if the current weather has an impact on the transmit power, the step of compensating the transmit power attenuation value specifically includes:

[0028] Calculating the difference between the power of the signal and the standard transmit power value;

[0029] The difference is used as a compensation value for the transmission power of the wireless transceiver unit.

[0030] Preferably, the method further comprises:

[0031] Determining whether a process of determining the coordinate point of the vehicle causes a delay;

[0032] If a delay is caused, a compensation value of the vehicle position is calculated according to the speed of the vehicle and the delay time to determine the final coordinate point.

[0033] Preferably, the step of determining whether the process of determining the coordinate point of the vehicle causes a delay specifically includes:

[0034] When the vehicle is not moving, the positioning unit determines that a process of determining the coordinate point of the vehicle does not cause a delay;

[0035] When the vehicle is traveling, the positioning unit determines that a process of determining the coordinate point of the vehicle causes a delay.

[0036] Compared with the prior art, the vehicle positioning system and the vehicle positioning method provided in the embodiments of the present invention realize positioning by receiving the signal transmitted by the wireless transceiver unit installed on the street lamp through the positioning unit arranged on the vehicle, and when it is determined that the current weather has an impact on the transmitted signal, the signal is retransmitted after compensating for the transmission power attenuation value to improve the positioning accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of an implementation scheme of a vehicle positioning system of the present invention.

[0038] Figure 2 Schematic diagram of an ideal position relationship between a wireless transceiver unit and a vehicle in an embodiment of a vehicle positioning system of the present invention.

[0039] Figure 3 It is a schematic diagram of the actual position relationship between the wireless transceiver unit and the vehicle in one embodiment of the vehicle positioning system of the present invention.

[0040] Figure 4 It is a schematic diagram of a flow chart of an implementation method of a vehicle positioning method according to the present invention.

[0041] Main component symbols

[0042] Driving Positioning System10

[0043] Wireless transceiver unit 100

[0044] Positioning unit 101

[0045] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0046] See also Figure 1 As shown, Figure 1Schematic diagram of an embodiment of a vehicle positioning system 10 of the present invention. In this embodiment, the vehicle positioning system 10 includes a wireless transceiver unit 100 and a positioning unit 101. The wireless transceiver unit 100 is installed on a street lamp, and each street lamp is equipped with a wireless transceiver unit 100. The positioning unit 101 is set on the vehicle.

[0047] In this embodiment, the wireless transceiver unit 100 is used to transmit and receive signals, and is also used to determine whether the current weather has an impact on the transmission power, and when it is determined that the current weather has an impact on the transmission signal, the signal is retransmitted after compensating for the transmission power attenuation value. The positioning unit 101 is used to receive the signal transmitted by the wireless transceiver unit and determine the coordinate point of the vehicle based on the signal. The number of wireless transceiver units 100 is at least three, and the transmission power of each wireless transceiver unit 100 installed on the street lamp varies in different weather conditions, which may cause positioning errors. The difference between the transmission energy received by the two adjacent wireless transceiver units 100 on the street lamp and the standard transmission power value is used for compensation.

[0048] Specifically, each wireless transceiver unit 100 is preset with a standard transmission power value for receiving adjacent wireless transceiver units 100; when a wireless transceiver unit 100 receives a signal transmitted by an adjacent wireless transceiver unit 100, it is determined whether the power of the signal is within a preset range. If the power of the signal is not within the preset range, the current weather has an impact on the transmission power. If the current weather has an impact on the transmission power, a wireless transceiver unit 100 calculates the difference between the power of the signal and the standard transmission power value, and uses the difference as a compensation value for the transmission power of the wireless transceiver unit 100 before retransmitting the signal.

[0049] In actual applications, when two adjacent wireless transceiver units 100 on a street lamp are first installed, the transmission power received by each other is set as a standard. The received power will change due to weather changes or environmental changes. If it exceeds the preset range, it needs to be compensated. For example, when it is sunny when it is first installed, the standard value of the transmission power received by a wireless transceiver unit 100 is -10dBm. When it rains, the transmission power received by the wireless transceiver unit 100 is -12dBm, and the wireless transceiver unit 100 needs to be compensated by 2dBm.

[0050] In this embodiment, the positioning unit 101 is also used to determine whether the process of determining the coordinate point of the vehicle causes a delay. Specifically, the positioning unit 101 takes time to calculate and determine the coordinate point of the vehicle, and when the vehicle is driving, a displacement error will be generated, resulting in a positioning delay. That is, when the vehicle is not driving, the positioning unit determines that the process of determining the coordinate point of the vehicle does not cause a delay. When the vehicle is driving, the positioning unit determines that the process of determining the coordinate point of the vehicle causes a delay. If a delay is caused, the positioning unit 101 calculates the compensation value of the vehicle position according to the speed of the vehicle and the delay time to determine the final coordinate point. Specifically, the positioning unit 101 obtains the speed of the vehicle according to the driving record module inside the vehicle. Assuming that the current speed of the vehicle is 60km / h and the delay time is 1s, the offset of the vehicle is 16.67m. If the vehicle is driving north at this time, the positioning unit 101 compensates the compensation value 16.67 to the north to determine the final coordinate point.

[0051] See also Figure 2 As shown, Figure 2 The figure is a schematic diagram of the ideal position relationship between the wireless transceiver unit and the vehicle in an embodiment of the vehicle positioning system 10 of the present invention. As shown in the figure, under ideal conditions, circles are drawn with the transmitting signal ends of the three wireless transmitting units 100 as the center and d1, d2, and d3 as the radius, so that the three circles intersect at a point D. It is known that the positions of the centers of the three groups of wireless transceiver units 100 are A (X1, Y1), B (X2, Y2) and C (X3, Y3), respectively, and the position of the vehicle to be measured is D (X, Y). Under ideal conditions, the following situations exist:

[0052] (X-X1) 2 +(Y-Y1) 2 =d1 2 Formula (1)

[0053] (X-X2) 2 +(Y-Y2) 2 =d2 2 Formula (2)

[0054] (X-X3) 2 +(Y-Y3) 2 =d3 2 Formula (3)

[0055] However, in the actual positioning process, it will be disturbed and affected by external environmental factors. In the process of calculating the distance from the undetermined point D to the three known wireless transceiver units 100, it is possible that the three circles do not intersect at one point, such as Figure 3 , two circles intersect at two points, and three circles intersect at six points, which are:

[0056] The intersection points of circle A and circle B are (Xab1, Yab1), (Xab2, Yab2);

[0057] The intersection points of circle A and circle C are (Xac1, Yac1), (Xac2, Yac2);

[0058] The intersection points of circle B and circle C are (Xbc1, Ybc1), (Xbc2, Ybc2).

[0059] First, according to equations (1) and (2), we obtain the two intersection points (Xab1, Yab1) and (Xab2, Yab2) of circle A and circle B. According to equations (1) and (3), we solve the intersection points (Xac1, Yac1) and (Xac2, Yac2) of circle A and circle C. According to equations (2) and (3), we calculate the intersection points (Xbc1, Ybc1) and (Xbc2, Ybc2) of circle B and circle C. Then, we substitute the intersection points (Xac1, Yac1) and (Xac2, Yac2) of circle A and circle C into X-X2. 2 +Y-Y2 2 In the equation, find the point (Xac, Yac) that is closest to the center of circle B. Similarly, (Xab, Yab) and (Xbc, Ybc) can be found. Based on the calculation, the approximate coordinates of the coordinates to be located can be obtained.

[0060]

[0061] See also Figure 4 As shown, Figure 4 The flowchart of an embodiment of the vehicle positioning method of the present invention is shown in FIG. In this embodiment, the vehicle positioning method is applied to a vehicle positioning system 10, and the vehicle positioning system 10 includes a wireless transceiver unit 100 and a positioning unit 101. The wireless transceiver unit 100 is installed on a street lamp, and each street lamp is equipped with a wireless transceiver unit 100. The positioning unit 101 is set on the vehicle. The vehicle positioning method includes the following steps:

[0062] Step S31: the wireless transceiver unit 100 transmits a signal;

[0063] Step S32: Determine whether the current weather has an impact on the transmission power. If yes, proceed to step S33; if no, jump to step S35;

[0064] Specifically, there are at least two wireless transceiver units 100, and the transmission power of each wireless transceiver unit 100 installed on the street lamp varies in different weather conditions, which may cause positioning errors. In this embodiment, the step of determining whether the current weather has an impact on the transmission power specifically includes:

[0065] Presetting a standard transmission power value for each wireless transceiver unit to receive an adjacent wireless transceiver unit;

[0066] When a wireless transceiver unit receives a signal transmitted by an adjacent wireless transceiver unit, the difference between the power of the signal and the standard transmission power value is calculated;

[0067] Determining whether the power of the signal is within a preset range;

[0068] If the power of the signal is not within the preset range, the current weather has an impact on the transmission power.

[0069] Step S33: Compensating the transmission power attenuation value;

[0070] Specifically, if the current weather has an impact on the transmit power, the wireless transceiver unit 100 calculates the difference between the power of the signal and the standard transmit power value, and then uses the difference as a compensation value for the transmit power of the wireless transceiver unit.

[0071] Step S34: retransmit the signal;

[0072] Specifically, in actual applications, when two adjacent wireless transceiver units 100 on a street lamp are first installed, the transmission power received by each other is set as a standard. The received power will change due to weather changes or environmental changes, and if it exceeds the preset range, it needs to be compensated. For example, when it is sunny when it is first installed, the standard value of the transmission power received by a wireless transceiver unit 100 is -10dBm. When it rains, the transmission power received by the wireless transceiver unit 100 is -12dBm, and the wireless transceiver unit 100 needs to be compensated by 2dBm.

[0073] Step S35: the positioning unit receives the signal;

[0074] Step S36: Determine the coordinate point of the vehicle according to the signal.

[0075] Specifically, the process of calculating and determining the coordinate point of the vehicle by the positioning unit 101 takes time, and when the vehicle is moving, displacement errors will be generated, resulting in positioning delays. That is, when the vehicle is not moving, the positioning unit determines that the process of determining the coordinate point of the vehicle does not cause delays. When the vehicle is moving, the positioning unit determines that the process of determining the coordinate point of the vehicle causes delays. If delays are caused, the positioning unit 101 calculates the compensation value of the vehicle position according to the speed of the vehicle and the delay time to determine the final coordinate point.

[0076] Compared with the prior art, the vehicle positioning system and the vehicle positioning method provided in the embodiments of the present invention realize positioning by receiving the signal transmitted by the wireless transceiver unit installed on the street lamp through the positioning unit arranged on the vehicle, and when it is determined that the current weather has an impact on the transmitted signal, the signal is retransmitted after compensating for the transmission power attenuation value to improve the positioning accuracy.

[0077] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. As long as they are within the spirit of the present invention, appropriate changes and modifications to the above embodiments are within the scope of protection claimed by the present invention.

Claims

1. A vehicle positioning system, characterized in that: The vehicle positioning system comprises: The wireless transceiver unit is installed on the street lamp and is used to transmit signals. It is also used to determine whether the current weather has an impact on the transmission power. If it is determined that the current weather has an impact on the transmission signal, it will retransmit the signal after compensating for the transmission power attenuation value. A positioning unit is arranged on the vehicle and is used to receive the signal transmitted by the wireless transceiver unit and determine the coordinate point of the vehicle according to the signal. The number of the wireless transceiver units is at least three, wherein The positioning unit is further used to calculate the coordinates (X, Y) of the vehicle by using the first formula, the second formula and the third formula when there is no external interference: （1） （2） （3） (X1, Y1) are the coordinates of the first transceiver unit, d1 is the radius of a first circle with the first transceiver unit as the center, (X2, Y2) are the coordinates of the second transceiver unit, d2 is the radius of a second circle with the second transceiver unit as the center, (X3, Y3) are the coordinates of the third transceiver unit, d3 is the radius of the third circle with the second transceiver unit as the center, and (X, Y) are the coordinates of the intersection of the first circle, the second circle, and the third circle; The positioning unit is further used for: when the first circle, the second circle and the third circle do not intersect at one point and the three circles intersect at six points due to external interference: Determine two intersection points of the first circle and the second circle, and the intersection point closest to the third circle is (Xab, Yab); Determine two intersection points of the first circle and the third circle, and the intersection point closest to the second circle is (Xac, Yac); Determine two intersection points of the second circle and the third circle, and the intersection point closest to the first circle is (Xbc, Ybc); The coordinates of the vehicle are calculated by the fourth formula: (X, Y) = ( ) (4); where Each wireless transceiver unit is also used to preset a standard transmission power value for receiving adjacent wireless transceiver units; When a wireless transceiver unit receives a signal transmitted by an adjacent wireless transceiver unit, it determines whether the power of the signal is within a preset range. If the power of the signal is not within the preset range, it is determined that the current weather has an impact on the transmission power. If the current weather has an impact on the transmission power, the wireless transceiver unit calculates the difference between the power of the signal and the standard transmission power value, and uses the difference as a compensation value for the transmission power of the wireless transceiver unit before retransmitting the signal.

2. The vehicle positioning system according to claim 1, characterized in that: The positioning unit is also used for: determining whether a process of determining the coordinate point of the vehicle causes a delay; If a delay is caused, a compensation value of the vehicle position is calculated according to the speed of the vehicle and the delay time to determine the final coordinate point.

3. The vehicle positioning system according to claim 2, characterized in that: When the vehicle is not moving, the positioning unit determines that a process of determining the coordinate point of the vehicle does not cause a delay; When the vehicle is traveling, the positioning unit determines that a process of determining a coordinate point of the vehicle causes a delay.

4. A vehicle positioning method, characterized in that: Applied to a vehicle positioning system, the vehicle positioning system includes a wireless transceiver unit installed on a street lamp and a positioning unit arranged on a vehicle, the number of the wireless transceiver units is at least three, and the method includes: The wireless transceiver unit transmits a signal; Determine whether the current weather has an impact on the transmission power; If the current weather has an impact on the transmit power, compensate for the transmit power attenuation value; Retransmit the signal; The positioning unit receives the signal; Determine the coordinate point of the vehicle according to the signal, wherein the step of determining the coordinate point of the vehicle according to the signal specifically includes: When there is no external interference, the coordinates (X, Y) of the vehicle are calculated by the first formula, the second formula and the third formula: （1） （2） （3） (X1, Y1) are the coordinates of the first transceiver unit, d1 is the radius of a first circle with the first transceiver unit as the center, (X2, Y2) are the coordinates of the second transceiver unit, d2 is the radius of a second circle with the second transceiver unit as the center, (X3, Y3) are the coordinates of the third transceiver unit, d3 is the radius of the third circle with the second transceiver unit as the center, and (X, Y) are the coordinates of the intersection of the first circle, the second circle, and the third circle; When the first circle, the second circle and the third circle do not intersect at one point and the three circles intersect at six points due to external interference: Determine two intersection points of the first circle and the second circle, and the intersection point closest to the third circle is (Xab, Yab); Determine two intersection points of the first circle and the third circle, and the intersection point closest to the second circle is (Xac, Yac); Determine two intersection points of the second circle and the third circle, and the intersection point closest to the first circle is (Xbc, Ybc); The coordinates of the vehicle are calculated by the fourth formula: (X, Y) = ( ) (4); wherein the step of determining whether the current weather has an impact on the transmission power specifically includes: Presetting a standard transmission power value for each wireless transceiver unit to receive an adjacent wireless transceiver unit; When a wireless transceiver unit receives a signal transmitted by an adjacent wireless transceiver unit Determining whether the power of the signal is within a preset range; If the power of the signal is not within the preset range, the current weather has an impact on the transmission power; If the current weather has an impact on the transmission power, the wireless transceiver unit calculates the difference between the power of the signal and the standard transmission power value; The difference is used as a compensation value of the transmission power of the wireless transceiver unit and then the signal is retransmitted.

5. The vehicle positioning method according to claim 4, characterized in that: Also includes: Determining whether a process of determining the coordinate point of the vehicle causes a delay; If a delay is caused, a compensation value of the vehicle position is calculated according to the speed of the vehicle and the delay time to determine the final coordinate point.

6. The vehicle positioning method according to claim 5, characterized in that: The step of determining whether the process of determining the coordinate point of the vehicle causes a delay specifically includes: When the vehicle is not moving, the positioning unit determines that a process of determining the coordinate point of the vehicle does not cause a delay; When the vehicle is traveling, the positioning unit determines that a process of determining the coordinate point of the vehicle causes a delay.

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