A precise parking method for shared electric vehicles

Abstract

The present invention discloses a precise parking method for a shared electric vehicle, and relates to the technical field of shared bicycle communication. The method comprises the following steps: firstly, a parking area is selected by using a planned parking area frame, secondly, the parking area is confirmed by scanning using the WiFi scan technology, and finally, the parking position and the parking direction are accurately determined by combining the Bluetooth technology to ensure the spacing during parking. The present invention can quickly confirm whether there are shared bicycles around through Bluetooth broadcasting, so as to confirm the parking point. Compared with the traditional GPS positioning, the method has a faster response, and can also ensure that the shared electric vehicle is parked near the electric vehicle that has been parked, so as to avoid the electric vehicle being parked randomly in the parking area. At the same time, the WiFi signal is used as an auxiliary means to quickly provide the user with the nearest parking space, so as to reduce the time for the user to find a suitable parking space, and can also effectively ensure that the user parks the electric vehicle in a reasonable direction.

Description

Technical Field

[0001] The present invention relates to the field of shared bicycle communication technology, and in particular to a precise parking method for a shared electric vehicle. Background Art

[0002] Urban shared electric vehicles are an emerging urban transportation mode that aims to meet the needs of urban residents for short-distance travel, especially playing an important role in solving the "last mile" transportation problem. Shared electric vehicles are usually put on the market by enterprises, and users rent them through mobile phone applications and are charged according to usage time or mileage. They play a positive role in alleviating urban traffic congestion, reducing automobile exhaust emissions, and improving urban transportation efficiency.

[0003] However, during our investigation and use over a long period of time, we found that most shared electric vehicles today use GPS for positioning, which results in long response times and inaccurate positioning. There is also a lack of an effective mechanism to determine whether the vehicle is in a permitted parking area, which results in very poor placement of shared electric vehicles at parking spots, which are basically randomly parked. The utilization rate of the parking area at a parking spot is very low, causing some users to park their vehicles at the edge or in the aisle, affecting traffic and having a relatively large impact on the cityscape. Summary of the invention

[0004] The purpose of the present invention is to provide a precise parking method for shared electric vehicles, combining low-power Bluetooth and WiFiscan technology to provide a high-precision and convenient shared bicycle positioning system to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a precise parking method for a shared electric vehicle, comprising the following steps:

[0006] Step 1: Obtain the parking area. The cloud system platform obtains the planned parking area data, and uses the corresponding graphics to frame the parking area according to the obtained parking area data, and marks it as the framed parking area. At the same time, the public WIFI signal data in the framed parking area is obtained, and a WIFI signal database is established;

[0007] Step 2: Preliminary confirmation of parking. The shared electric vehicle is equipped with a corresponding Bluetooth module and a WiFiscan module. The front and rear of the shared electric vehicle are respectively equipped with signal antenna groups. When the shared electric vehicle drives towards the selected parking area, the corresponding WiFiscan module quickly scans and identifies the public WiFi signals in the selected parking area, and compares them with the established WiFi signal database. When there is at least one paired WiFi signal, it can be quickly confirmed that the shared electric vehicle has entered the selected parking area.

[0008] Step 3: Parking point division, with the first shared electric vehicle parked in the selected parking area as the center, and the area radiating outward from the Bluetooth signal as the starting parking area. When other shared electric vehicles are initially confirmed to enter the selected parking area, the corresponding Bluetooth module scans the Bluetooth signals of other shared electric vehicles nearby. When there is a shared electric vehicle Bluetooth signal, the parking area in the selected parking area can be quickly confirmed;

[0009] Step 4: Accurately identify the parking spot. After the shared electric vehicle enters the parking area, the corresponding Bluetooth module extracts at least one Bluetooth signal arranged from near to far, and feeds back the shared electric vehicle number corresponding to the extracted Bluetooth signal. The user moves the shared electric vehicle to the side of the shared electric vehicle corresponding to the number according to the fed-back number.

[0010] Step 5: Determine the parking direction. The signal antenna group in the shared electric vehicle to be parked receives the Bluetooth signal sent by the Bluetooth module of the shared electric vehicle corresponding to the number, analyzes and processes it, records the phase difference of the signals received by different signal antenna groups, and calculates the angle θ of the signal arrival at the front and rear of the vehicle respectively. 1 With θ 2 , then the standard parking angle P = |θ 1 -θ 2 |You can return the car and park it within the set safety angle.

[0011] Preferably, in step one, the location information of each framed parking area is paired with the acquired public WIFI signal, and the public WIFI signal acquired in each framed parking area can cover the corresponding framed parking area. When there is no public WIFI signal in the framed parking area, at least one WIFI signal source is set up at the center position as the public WIFI signal.

[0012] Preferably, in the step three, the first shared electric vehicle parked in the selected parking area radiates Bluetooth signals in a circular area with itself as the center and the length of at least one electric vehicle as the radius, and the overlapping part of the circular area and the selected parking area is used as the starting parking area, and each shared electric vehicle can radiate the circular area.

[0013] Preferably, the Bluetooth module and the WiFiscan module are both installed at the center of the shared electric vehicle, and the signal antenna group is an even number of signal antennas, and at least two, which are symmetrically installed on the left and right sides of the front or rear of the shared electric vehicle.

[0014] Preferably, in step 5, the angle θ of signal arrival is calculated as follows: the signal antennas at the front and rear ends of the shared electric vehicle to be parked receive the Bluetooth signals emitted by the shared electric vehicle with the corresponding numbers, respectively, wherein the distance between the two signal antennas in the same signal antenna group is set to d, and then the phase difference is calculated, the phase difference Δ between the two antennas φ =2πfΔt, where f is the frequency of the signal, Δt is the time difference between the signal reaching the two signal antennas, and according to the phase difference Δ φ Calculate the angle θ of the signal arrival: θ=arcsin((Δ φλ ) / (2πd)), where λ is the wavelength of Bluetooth signal.

[0015] Preferably, when a shared electric vehicle to be parked enters next to a shared electric vehicle corresponding to a number, a standard parking angle between the shared electric vehicle to be parked and the shared electric vehicle corresponding to the number is displayed in real time on a display screen of the shared electric vehicle to be parked.

[0016] Preferably, when areas not covered by the radial circular area appear continuously in the framed parking area, the corresponding areas are marked as no-parking areas.

[0017] In summary, the beneficial effects of the present invention are:

[0018] The present invention can quickly confirm whether there are shared bicycles around through Bluetooth broadcasting, so as to confirm the parking spot. Compared with traditional GPS positioning, it has a faster response, and can also ensure that the shared electric vehicle is parked near the already parked electric vehicle, avoiding the electric vehicle from being parked randomly in the parking area. At the same time, using WiFi signals as an auxiliary means, it can quickly provide users with the nearest parking space, which is convenient for users to park, reduces the time for users to find suitable parking spaces, improves user experience, and can effectively ensure that users park the electric vehicles in a reasonable direction, allowing users to park and arrange the shared electric vehicles neatly, maximizing the use of the area of ​​the parking area to park a sufficient number of shared electric vehicles, and greatly improving the area utilization rate of the parking area. It can also effectively avoid the phenomenon of random parking, greatly improving the city's appearance, and it is also very convenient for users to use shared electric vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1A schematic diagram of the process framework structure of a precise parking method for a shared electric vehicle according to the present invention;

[0021] Figure 2 A schematic diagram of a Bluetooth scanning process of a precise parking method for a shared electric vehicle according to the present invention;

[0022] Figure 3 A schematic diagram of a WiFi scanning process of a precise parking method for a shared electric vehicle according to the present invention;

[0023] Figure 4 A schematic diagram of the installation of a signal antenna for a shared electric vehicle in a precise parking method for a shared electric vehicle according to the present invention;

[0024] Figure 5 A schematic diagram of an electric vehicle parking area for a precise parking method for a shared electric vehicle according to the present invention;

[0025] Figure 6 A schematic diagram of a Bluetooth signal scanning parking point for a precise parking method for a shared electric vehicle according to the present invention;

[0026] Figure 7 A schematic diagram of a standard parking angle of a precise parking method for a shared electric vehicle according to the present invention;

[0027] Figure 8 A schematic diagram of an incorrect parking direction of a precise parking method for a shared electric vehicle according to the present invention;

[0028] Fig. 9 Schematic diagram of parking at different positions according to a precise parking method for a shared electric vehicle of the present invention. DETAILED DESCRIPTION

[0029] The present invention will now be further described in detail in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. These drawings are all simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic way, and therefore they only show the structures related to the present invention.

[0030] To facilitate understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0031] All features disclosed in this specification, or steps in all methods or processes disclosed, except mutually exclusive features and / or steps, can be combined in any manner.

[0032] Any feature disclosed in this specification (including any additional claims, abstract and drawings), unless otherwise stated, may be replaced by other equivalent or alternative features with similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0033] In the present invention, unless otherwise clearly defined and specified, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of at least two elements or the interaction relationship between at least two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] Combine the following Figure 1-9 The present invention is described in detail. An embodiment of the present invention is: a precise parking system for a shared electric vehicle, comprising a cloud system platform and a shared electric vehicle, wherein the cloud system platform adopts a SAAS platform, a Bluetooth module and a WiFiscan module are installed in the central area of ​​the shared electric vehicle, each shared electric vehicle is paired with a corresponding Bluetooth signal, and a database containing all shared electric vehicle Bluetooth signals is established, each Bluetooth signal corresponds to a digital number, and a signal antenna group is installed at the front and rear of each shared electric vehicle, respectively. The signal antenna groups are an even number and are evenly installed on the left and right sides of the electric vehicle. For convenience and cost saving, two signal antennas A1 and A2 are selected here, reference Figure 4 ;

[0035] Step 1: Get the parking area

[0036] The cloud system platform uses third-party map APIs (such as Google Maps API, Amap API, Baidu Map API, etc.) to obtain the approved planned parking area data in the current area. Based on the acquired planned parking area data, the best rule graphic is selected to frame the planned parking area and marked as the framed parking area in the cloud system platform. Figure 5For example, in the shared electric vehicle parking area near the subway entrance, the planned parking area is framed with a rectangular shape, and the area framed by the outer rectangular frame is marked as the framed parking area. Considering the slight difference between the approved planned parking area and the actual terrain, the framed parking area that is larger than the planned parking area is framed, which is conducive to the subsequent use of data stacking to gradually refine it into an accurate parking area;

[0037] Then obtain the public WIFI signal data in the selected parking area and establish a WIFI signal database.

[0038] The location information of each selected parking area is paired with the acquired public WIFI signal. The location information of each selected parking area can be paired with multiple public WIFI signals. The more signals there are, the more accurate the location identification is. The acquired public WIFI signal can cover the corresponding selected parking area. In this case, there will be a situation where there is no public WIFI signal in the selected parking area. In this case, at least one WIFI signal source can be built near the central area as a public WIFI signal. Here we choose to build three WIFI signal sources, distributed in the center of the selected parking area.

[0039] Step 2: Parking spot division

[0040] There are two situations here. One is that there are no shared electric vehicles parked in the selected parking area. The other is that there are collectively dispatched shared electric vehicles in the selected parking area. When there are not enough electric vehicles in a certain area, it is often necessary to dispatch shared electric vehicles from other areas. Therefore, the dispatched shared electric vehicles are often parked in the selected parking area without shared electric vehicles.

[0041] When facing the first situation, there is no shared electric vehicle parked in the selected parking area. Then, when the first shared electric vehicle enters the selected parking area, the corresponding WiFiscan module in the shared electric vehicle quickly scans and identifies the public WiFi signal in the selected parking area, and compares it in the established WiFi signal database. When there is at least one paired WiFi signal, it can be quickly confirmed that the shared electric vehicle has entered the selected parking area. The further the shared electric vehicle moves toward the center of the selected parking area, the more public WiFi signals it scans, thereby better confirming its location. At this time, for the first shared electric vehicle parked in the selected parking area, a "first stop" will appear on the user's mobile terminal. Option, after the user clicks, the cloud system platform can park after confirmation, so there is no need to use GPS positioning parking. Compared with the existing shared electric vehicle parking solutions, it has a faster response confirmation time. After the user parks the first shared electric vehicle in the selected parking area, the first shared electric vehicle takes its own center as the center point and a distance of at least the length of a shared electric vehicle as the radius. Since the length of the shared electric vehicles we commonly use is about 1.5 meters, we choose a distance of 3 meters as the radius here to radiate the Bluetooth signal. The transmission power of Bluetooth can be controlled to control the radiation distance. The overlapping part of the circular area radiated by the Bluetooth signal and the selected parking area is used as the starting parking area. Figure 5 , with the first shared electric vehicle as the center, the 3-meter circular distance around it is the parking area in the framed parking area, which is set as parking area 1;

[0042] At this time, when the second shared electric vehicle needs to park, just like the first shared electric vehicle, it will first scan and identify the public WIFI signal in the selected parking area, and make a preliminary confirmation that it has entered the range of the selected parking area. After completing the preliminary confirmation, the "first stop" option will not appear. The Bluetooth module on the second shared electric vehicle will scan and scan the Bluetooth signals of other shared electric vehicles nearby. When the Bluetooth signals of other shared electric vehicles are not scanned, even if it enters the selected parking area, it cannot return the vehicle. It is necessary to enter the parking area 1 and scan the Bluetooth signal of the first shared electric vehicle to prepare for parking. After the second shared electric vehicle is parked, it will also radiate like the first shared electric vehicle to form the parking area 2, and the parking area 1 and the parking area 2 will be combined to form the parking area in the selected parking area. Similarly, when the Nth shared electric vehicle is ready to park, the parking area N will be formed in the selected parking area, and the parking area formed by the combination of the parking area 1, the parking area 2, ... the parking area N will cover the selected parking area.

[0043] After long-term operation, an operation time can be set for each selected parking area, which can be one month or three months. The time is set longer if the traffic volume is small and shorter if the traffic volume is large. During this set time, if there are continuous areas in the selected parking area that are not covered by the parking area N, the corresponding area will be marked with a shaded part as a non-parking area. The actual data is used to divide the selected parking area into parking areas and non-parking areas, making the parking area division of shared electric vehicles more accurate and reliable.

[0044] The parking location of shared electric vehicles is confirmed by Bluetooth signals and WiFi scan to confirm whether parking is possible, and it can also ensure that shared electric vehicles are parked near already parked electric vehicles, avoiding random parking of electric vehicles in the parking area and ensuring the number of electric vehicles parked in the area;

[0045] When facing the second situation, the scheduled shared electric vehicles are often arranged in a relatively neat manner. At this time, the shared electric vehicle among the scheduled shared electric vehicles close to the center of the selected parking area will be the first shared electric vehicle to be parked in the selected parking area.

[0046] Step 3: Accurate parking spots

[0047] After the shared electric vehicle that is about to park scans the Bluetooth signal through the Bluetooth module to confirm that it has entered the parking area, the Bluetooth module will quickly scan and identify the Bluetooth signals on other shared electric vehicles, and extract at least one Bluetooth signal from the distance arranged from near to far. When extracting a Bluetooth signal, refer to Figure 6 When the user enters the parking area from the right, the Bluetooth module will extract the Bluetooth signal CMD1 of the nearest shared electric vehicle numbered 001, and then feed it back to the cloud system platform. The cloud system platform will compare the data in the database of shared electric vehicle Bluetooth signals, and feed back the shared electric vehicle number 001 corresponding to the Bluetooth signal CMD1 to the user, and display it on the display screen of the shared electric vehicle to be parked, so that the user can intuitively find the corresponding shared electric vehicle according to the feedback number, and park the shared electric vehicle next to the shared electric vehicle with the corresponding number. The number plate of each shared electric vehicle is set on the rear side of the seat;

[0048] When extracting two WiFi signals, refer to Figure 6, when a user enters the parking area from the left, the Bluetooth module will extract the Bluetooth signals CMD3 and CMD4 of the two nearest shared bicycles 003 and 004, and also feed them back to the cloud system platform. The cloud system platform compares the data in the Bluetooth database, feeds back the shared electric vehicle number corresponding to the Bluetooth signal to the user, and displays it on the display screen of the shared electric vehicle to be parked, so that the user can intuitively find the corresponding shared electric vehicle according to the feedback number. At this time, the user can choose to park and choose a suitable parking location according to his actual situation;

[0049] When the user selects a shared electric vehicle with a suitable number to park next to, in order to prevent the user from randomly placing the electric vehicle and returning it, when the user moves the shared electric vehicle to be parked next to the shared electric vehicle with a number, the signal antenna group will receive the Bluetooth signal sent by the Bluetooth module of the shared electric vehicle with the corresponding number, and then analyze and process it. Figure 7 , the Bluetooth module in the shared electric vehicle with the corresponding number is used as the base station to transmit the Bluetooth signal. The signal antenna groups A and B at the front and rear of the shared electric vehicle to be parked receive the Bluetooth signal respectively, and the phase difference of the signals received by different signal antenna groups is recorded. The angle θ of the signal arrival at the front and rear of the vehicle is calculated respectively. 1 With θ 2 ;

[0050] First, a Cartesian coordinate system is established with the Bluetooth signal source of the shared electric vehicle corresponding to the number. The direction of the vehicle head is the positive direction of the y-axis, and the direction perpendicular to the right is the positive direction of the x-axis.

[0051] For the front θ 1 :The distance between the signal antennas A1 and A2 on both sides of the front of the vehicle is d, the frequency of the signal is f, and the time difference between the signal reaching the two signal antennas is Δt, then the phase difference between the two signal antennas Δ φ =2πfΔt, and then calculate the angle θ of the signal arrival based on the obtained phase difference: θ=arcsin((Δ φλ ) / (2πd)), where λ is the WiFi signal wavelength, λ =speed of light / f;

[0052] For example: When the Bluetooth signal frequency f=2.4GHz is selected, the wavelength λ = speed of light / f ≈ 0.125 m, the phase difference between A1 and A2 Δ φ≈1.5π, and the spacing between antennas A1 and A2 is set to a wavelength length spacing, d=0.125 meters. If the antenna spacing d is too large, it may cause phase ambiguity, that is, the phase difference exceeds 2π, making the angle calculation uncertain. Therefore, in order to ensure sensitivity, one wavelength is selected as the spacing between the antennas, so that θ can be calculated. 1 ≈49°; Similarly, the rear θ can be calculated 2 ≈51°, due to the rear θ 2 In the fourth quadrant, the calculation is performed with a negative number, so the standard parking angle of the shared electric vehicle P=|θ 1 -θ 2 |You can return the car and park it within the set safety angle;

[0053] The range of the safety angle is calculated through multiple experiments. Figure 8 ,in Figure 8 8.1 in the figure shows that the electric vehicle is parked at an angle, with most of the vehicle exposed. 1 With the rear θ 2 are all located in the fourth quadrant, then the standard parking angle P = |θ 1 -θ 2 | is bound to be an acute angle, where Figure 8 8.2 in the figure is the state of the electric vehicle being parked horizontally. It can be clearly seen that 0≤P<90°, so it is an irregular parking angle and cannot be parked. At this time, a red flashing will appear on the display screen of the shared electric vehicle to remind you that you cannot park in this direction.

[0054] refer to Fig. 9 ,in Fig. 9 Although the 9.1 in the figure are parked neatly, the parking distance is too close, which will cause collisions between adjacent electric vehicles, making P too large. Fig. 9 9.2 of the above is for standard parking, with a moderate parking distance. Fig. 9 9.3 in the figure indicates that the parking distance is too far, which results in a small P. The distance between adjacent electric vehicles is too far, which can easily lead to a significant reduction in the number of vehicles that can be parked in a parking area, thus failing to effectively utilize the parking area.

[0055] In the process of continuous experimental spacing, taking the standard parking method as an example, the sideways position of an adult is used as the minimum parking spacing between two adjacent shared electric vehicles, which is about 30 cm. The maximum parking spacing is the body width of two adults, which is about 75 cm. Considering the convenience and safety of users when parking and picking up the car, the experimental safety angle is calculated based on the body length of the shared electric vehicle. The average length of shared electric vehicles on the market is taken as the value, which is about 150 cm. The maximum and minimum safety angles of parking are calculated. Therefore, when the angle value of P is within the range of the maximum and minimum safety angles, green will appear on the display screen of the shared electric vehicle, indicating that parking and changing vehicles can be carried out. The shared electric vehicle will feedback the return instruction to the cloud system, and the cloud system will send the instruction to the user's mobile terminal, and the user can execute the return.

[0056] It should be noted that in order to facilitate users to adjust the return angle of the electric vehicle, the standard parking angle P will be displayed in real time on the display screen of the shared electric vehicle;

[0057] This can effectively ensure that users park their electric vehicles in a reasonable direction, effectively avoiding the phenomenon of random parking, so that the electric vehicles are parked neatly at the parking spots for shared electric vehicles, greatly improving the city's appearance, and it is also very convenient for users to use shared electric vehicles.

[0058] To sum up, the present invention can quickly confirm whether there are shared bicycles around through Bluetooth broadcasting, so as to confirm the parking spot. Compared with traditional GPS positioning, it has a faster response, and can also ensure that the shared electric vehicle is parked near the already parked electric vehicle, avoiding the random parking of electric vehicles in the parking area. At the same time, using WiFi signals as an auxiliary means, it can quickly provide users with the nearest parking space, which is convenient for users to park, reduces the time for users to find suitable parking spaces, improves user experience, and effectively ensures that users park electric vehicles in a reasonable direction, allowing users to park shared electric vehicles neatly and arrange them, maximizing the use of the parking area to park a sufficient number of shared electric vehicles. The area utilization rate of the parking area is also greatly improved, and it can effectively avoid the phenomenon of random parking, greatly improving the city's appearance, and it is also very convenient for users to use shared electric vehicles.

[0059] The above is only a specific implementation of the invention, but the protection scope of the invention is not limited to it. Any changes or substitutions that are not conceived through creative work should be included in the protection scope of the invention. Therefore, the protection scope of the invention should be based on the protection scope defined in the claims.

Claims

1. A precise parking method for a shared electric vehicle, characterized by: The following steps are involved: Step 1: Obtain the parking area. The cloud system platform obtains the planned parking area data, and uses the corresponding graphics to frame the parking area according to the obtained parking area data, and marks it as the framed parking area. At the same time, the public WIFI signal data in the framed parking area is obtained, and a WIFI signal database is established; Step 2: Preliminary confirmation of parking. The shared electric vehicle is equipped with a corresponding Bluetooth module and a WiFiscan module. The front and rear of the shared electric vehicle are respectively equipped with signal antenna groups. When the shared electric vehicle drives towards the selected parking area, the corresponding WiFiscan module quickly scans and identifies the public WiFi signals in the selected parking area, and compares them with the established WiFi signal database. When there is at least one paired WiFi signal, it can be quickly confirmed that the shared electric vehicle has entered the selected parking area. Step 3: Parking point division, with the first shared electric vehicle parked in the selected parking area as the center, and the area radiating outward from the Bluetooth signal as the starting parking area. When other shared electric vehicles are initially confirmed to enter the selected parking area, the corresponding Bluetooth module scans the Bluetooth signals of other shared electric vehicles nearby. When there is a shared electric vehicle Bluetooth signal, the parking area in the selected parking area can be quickly confirmed; Step 4: Accurately identify the parking spot. After the shared electric vehicle enters the parking area, the corresponding Bluetooth module extracts at least one Bluetooth signal arranged from near to far, and feeds back the shared electric vehicle number corresponding to the extracted Bluetooth signal. The user moves the shared electric vehicle to the side of the shared electric vehicle corresponding to the number according to the fed-back number. Step 5: Determine the parking direction. The signal antenna group in the shared electric vehicle to be parked receives the Bluetooth signal emitted by the Bluetooth module of the shared electric vehicle corresponding to the number, analyzes and processes it, records the phase difference of the signals received by different signal antenna groups, and calculates the angles θ1 and θ2 of the signal arrival at the front and rear of the vehicle respectively. The standard parking angle P=|θ1-θ2| can be used to return the vehicle when it is within the set safety angle.

2. According to claim 1, a precise parking method for a shared electric vehicle is characterized by: In the step one, the location information of each framed parking area is paired with the acquired public WIFI signal, and the public WIFI signal acquired in each framed parking area can cover the corresponding framed parking area. When there is no public WIFI signal in the framed parking area, at least one WIFI signal source is set up at the center position as the public WIFI signal.

3. According to claim 1, a precise parking method for a shared electric vehicle is characterized by: In the step three, the first shared electric vehicle parked in the selected parking area radiates Bluetooth signals in a circular area with itself as the center and the length of at least one electric vehicle as the radius. The overlapping part of the circular area and the selected parking area is used as the starting parking area, and each shared electric vehicle can radiate the circular area.

4. According to claim 3, a precise parking method for a shared electric vehicle is characterized by: The Bluetooth module and the WiFiscan module are both installed at the center of the shared electric vehicle. The signal antenna group is an even number of signal antennas, and at least two, which are symmetrically installed on the left and right sides of the front or rear of the shared electric vehicle.

5. According to claim 4, a precise parking method for a shared electric vehicle is characterized in that: In step 5, the angle θ of signal arrival is calculated as follows: the signal antennas at the front and rear ends of the shared electric vehicle to be parked receive the Bluetooth signals emitted by the shared electric vehicle with the corresponding numbers respectively, wherein the distance between the two signal antennas in the same signal antenna group is set to d, and then the phase difference is calculated. The phase difference Δ between the two antennas φ =2πfΔt, where f is the frequency of the signal and Δt is the time difference between the signal arriving at the two signal antennas; According to the phase difference Δ φ Calculate the angle θ of the signal arrival: θ=arcsin((Δ φλ ) / (2πd)), where λ is the wavelength of Bluetooth signal.

6. According to claim 5, a precise parking method for a shared electric vehicle is characterized by: When a shared electric vehicle that is ready to park enters next to a shared electric vehicle corresponding to a number, the display screen of the shared electric vehicle that is ready to park displays the standard parking angle between the shared electric vehicle and the shared electric vehicle corresponding to the number in real time.

7. A precise parking method for a shared electric vehicle according to claim 3, characterized in that: When areas that are not covered by the radial circular area appear continuously in the framed parking area, the corresponding areas are marked as no-parking areas.

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