Electric vehicle wireless charging alignment system and method based on Bluetooth beacon

Abstract

The present invention discloses a wireless charging alignment system and method for electric vehicles based on Bluetooth beacons. The charging alignment system includes a main control unit, a ground control unit connected to the main control unit, a receiving coil and a Bluetooth beacon arranged on the vehicle to be charged, and a transmitting coil and a communication receiver arranged at a parking lot. There are multiple groups of communication receivers, including a first group of communication receivers and a second group of communication receivers respectively located on the left and right sides of the vehicle to be charged, and a third group of communication receivers located on the front side of the vehicle to be charged. The charging alignment system is simple and has strong applicability. The position of the receiving coil is located by the Bluetooth beacon, which not only avoids the differences in the fixed installation positions caused by different brands and different models, but also avoids the problems caused by the abnormal displacement of the receiving coil for some reason.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless charging, and in particular to a wireless charging alignment system and method for electric vehicles based on Bluetooth beacons. Background Art

[0002] Wireless charging has the advantages of convenient charging, high safety, long service life, and perfect automation. It is one of the important development directions of electric vehicle charging technology. Wireless charging of electric vehicles usually uses the transmitting coil on the ground side and the receiving coil on the vehicle side to achieve non-contact transmission of electric energy through the principle of magnetic coupling (electromagnetic induction or electromagnetic resonance) and charge the power battery of the electric vehicle. Based on the basic principle of electromagnetic coupling, the relative position of the transmitting coil and the receiving coil will have a very large impact on the coupling coefficient. When the transmitting coil and the receiving coil are aligned, the coil coupling coefficient is the largest and the wireless charging efficiency is also the highest. Therefore, the alignment of the transmitting coil and the receiving coil is the key to high-efficiency wireless charging of electric vehicles.

[0003] In the existing wireless charging system invention, the alignment system adopted is mostly an automatic parking system, which guides the position adjustment based on the judgment of the distance between the sensor and the car body to determine the position of the car. The alignment system currently has the following problems: 1) There are many types of car brands and models. Although the installation position of the receiving coil of the same brand model is consistent, the relative position of different models may not be consistent. Some systems do not add a model identification system to achieve differentiation in reality; 2) Even if some alignment systems add a car attribute database to identify, the workload and cost are too cumbersome and costly for the implementation of the system; 3) When the car moves at high speed for a long time, it is difficult to ensure whether the relative position of the receiving coil has a low stroke displacement, and it is difficult for the control system to achieve accuracy through positioning through upper-level parameters; 4) The existing system is mostly idealized and does not consider the closed loop, and does not detect whether there is a positioning failure caused by interference or obstruction of the sensor in reality. How to solve the above technical problems is what the technicians in this field are committed to solving. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide an electric vehicle wireless charging alignment system based on Bluetooth beacons, which uses Bluetooth to directly locate the receiving coil to guide the car to park, and then uses the principle of electromagnetic induction to accurately adjust the positioning after entering the range.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a wireless charging alignment system for electric vehicles based on Bluetooth beacons, including a main control unit, a ground control unit communicatively connected to the main control unit, a receiving coil and a Bluetooth beacon arranged on the vehicle to be charged, and a transmitting coil and a communication receiver arranged in a parking lot. There are multiple groups of communication receivers, including a first group of communication receivers and a second group of communication receivers respectively located on the left and right sides of the vehicle to be charged and a third group of communication receivers located on the front side of the vehicle to be charged. The Bluetooth beacon is used to send a broadcast signal, and the communication receiver is used to modulate and demodulate the received broadcast signal to form data for transmission to the ground control unit, and the ground control unit transmits the data to the main control unit; the main control unit calculates and analyzes the received data to obtain the actual coordinates of the receiving coil, and then compares the actual coordinates of the receiving coil with the target coordinates of the receiving coil previously stored and transmits the information back to the ground control unit, and the ground control unit adjusts the relative position between the receiving coil and the transmitting coil.

[0006] As a specific implementation manner, the first group of communication receivers, the second group of communication receivers, and the third group of communication receivers each include at least two communication receivers.

[0007] As a specific implementation manner, the first communication receiver and the second communication receiver are installed at the same horizontal height, and the installation height of the third communication receiver is higher than the installation heights of the remaining two groups of communication receivers.

[0008] As a specific implementation manner, the communication receiver and the main control unit are connected in 4G communication mode.

[0009] As a specific implementation, the charging alignment system further includes a positioning plate arranged in the parking lot, a feedback system is installed at the bottom of the positioning plate, and the transmitting coil is installed at the bottom of the positioning plate. The feedback system is used for feedback adjustment when interference occurs in Bluetooth beacon positioning or there is an offset in signal reflection.

[0010] As a specific implementation, the feedback system includes a plurality of feedback coils arranged in an array at the bottom of the positioning plate.

[0011] Another object of the present invention is to provide an electric vehicle wireless charging alignment method based on a Bluetooth beacon, comprising the following steps:

[0012] 1) Install the hardware equipment locally, power it on after installation, and the operator carries the beacon broadcaster to the transmitting coil end to start the broadcast signal. After receiving the broadcast signal, the communication receiver modulates and demodulates the data and transmits it to the ground control unit. The ground control unit then sends the data to the main control unit, and the rectangular coordinate system is constructed in the main control unit. At the same time, the main control unit stores the coordinate value of the transmitting coil and the target coordinate of the receiving coil, and the ground control unit enters the sleep state;

[0013] 2) The car to be charged drives into the parking lot, and the Bluetooth beacon installed on the car to be charged sends out a broadcast signal. After receiving the broadcast signal sent by the Bluetooth beacon, the communication receiver modulates and demodulates the data and transmits it to the ground control unit. The ground control unit determines whether the communication receiver is triggered by mistake based on the content of the broadcast signal and the frequency of receiving data. If it is a false trigger, it will continue to receive for 15 seconds and then enter the sleep state again; if it is not a false trigger, proceed to step 3);

[0014] 3) The ground control unit refreshes the received data at a high frequency and sends the data to the main control unit. The main control unit calculates and analyzes the obtained data, determines the actual coordinates of the receiving coil, and compares it with the stored target coordinates of the receiving coil. The information is then sent back to the ground control unit, which controls the relative position between the receiving coil and the transmitting coil.

[0015] Due to the application of the above technical scheme, the present invention has the following advantages compared with the prior art: the charging alignment system of the present invention directly locates the position of the receiving coil through the Bluetooth beacon, and no longer performs interlayer alignment through the position of the car, which not only avoids the differences in the fixed installation position caused by different brands and different models, but also avoids the problems caused by abnormal displacement of the receiving coil for some reason; at the same time, a peripheral feedback system is applied to avoid the problem of no negative feedback control closed loop when the Bluetooth beacon signal strength is disturbed; at the same time, the time and error due to the driver's self-adjustment are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the electric vehicle wireless charging alignment system based on Bluetooth beacons according to the present invention;

[0017] Figure 2 for Figure 1 A top view of

[0018] Figure 3 A flowchart of alignment of the electric vehicle wireless charging alignment system based on Bluetooth beacons according to the present invention;

[0019] Among them: 1. Bluetooth beacon; 2. Receiving coil; 3. Transmitting coil; 4. The first group of communication receivers; 5. The second group of communication receivers; 6. The third group of communication receivers; 7. Positioning board. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0021] A wireless charging alignment system for electric vehicles based on Bluetooth beacons includes a main control unit (not shown in the figure), a ground control unit (not shown in the figure) communicatively connected to the main control unit, a receiving coil 2 and a Bluetooth beacon 1 arranged on the vehicle to be charged, and a transmitting coil 3 and a communication receiver arranged in a parking lot.

[0022] The communication receiver has multiple groups, including a first group of communication receivers 4 and a second group of communication receivers 5 located on the left and right sides of the car to be charged, and a third group of communication receivers 6 located on the front side of the car to be charged. After the car to be charged enters the parking lot, the Bluetooth beacon (positioning beacon) 1 sends a broadcast signal. After receiving the broadcast signal, the communication receiver modulates and demodulates the data and transmits it to the ground control unit (ground central control). The ground control unit uploads the data to the main control unit (server / computing unit). The main control unit calculates and analyzes the received data to obtain the actual coordinates of the receiving coil 2, and then compares it with the target coordinates of the receiving coil 2 previously stored and sends the information back to the ground control unit. The ground control unit adjusts the relative position between the receiving coil 2 and the transmitting coil 3, see Figure 3 As shown, specifically, the ground control unit transmits a signal to the application layer, and the application layer adjusts the relative position between the receiving coil 2 and the transmitting coil 3.

[0023] In this example, Bluetooth beacon 1 and receiving coil 2 are installed on the car to be charged at the same time, so that the dynamic position of receiving coil 2 can be obtained by positioning Bluetooth beacon 1. The communication receiver here uses RX receiver, and each of the three groups of communication receivers contains at least two RX receivers. Specifically, Bluetooth beacon 1 positioning here uses AOA (angle of arrival). The Bluetooth device installed at the position of receiving coil 2 (the receiving coil is installed according to national standards and car company standards) sends a broadcast signal when the electric car enters the charging area, and receives it through the RX receiver.

[0024] Here, the first group of communication receivers 4 and the second group of communication receivers 5 are installed at the same level, while the third group of communication receivers 6 is installed at a higher level than the other two groups of communication receivers. The entire layout is that there are two first group of communication receivers 4, two second group of communication receivers 5, and two third group of communication receivers 6, see Figure 1 , 2 shown.

[0025] The straight line where the two RX receivers in the third group of communication receivers 6 are located is the X-axis, the midpoint of the line segment formed by the two RX receivers is the zero point of the X-axis, the straight line where the two RX receivers in the first group of communication receivers 4 or the second group of communication receivers 5 are located is the Y-axis, and the midpoint of the line segment formed by the two RX receivers is the origin of the Y-axis, thereby constructing a rectangular coordinate system. Here, the installation height of the third group of communication receivers 6 is higher than the installation height of the other two groups of communication receivers, and its purpose is to improve the accuracy of positioning in the two-dimensional coordinate system through an orthogonal height difference.

[0026] In this example, the ground control unit and the main control unit are connected via 4G communication.

[0027] Here, the application layer can be connected to the ground control unit through the CAN port. The application layer here can be an unmanned driving system, or it can use vehicle-mounted IoT guidance or local screen projection guidance.

[0028] If an unmanned driving system is used, there must be a communication connection between the vehicle control and the cloud in the framework of the unmanned driving system. Here, the vehicle control communicates with the cloud via the ground control unit through 4G, and the cloud directly transmits the data to the vehicle control terminal;

[0029] If the application layer here adopts vehicle-mounted IoT guidance, that is, manual driving, the guidance content is projected onto the vehicle-mounted IoT system, and the vehicle-mounted IoT guides the driver to make manual adjustments through voice, visual navigation, etc., so its data interface is the same as above, and the data can be transmitted to the vehicle through 4G;

[0030] If the application layer here adopts local screen projection guidance, the human-machine interface screen projection in front of the charging pile is used to guide the driver to make self-adjustments. This application does not need to transmit data to the vehicle or the cloud. It only needs to arrange a serial port interface to transmit the data to the local control of the charging pile so that it can be projected onto the display screen.

[0031] In this example, the charging alignment system also includes a positioning plate 7 arranged in the parking lot, a feedback system is installed at the bottom of the positioning plate 7, and the transmitting coil 3 is installed at the bottom of the positioning plate 7. The feedback system is used for feedback adjustment when interference occurs in the positioning of the Bluetooth beacon 1 or there is an offset in the signal reflection. The feedback system includes a number of feedback coils (not shown in the figure) arranged in an array at the bottom of the positioning plate 7. The feedback current is collected through the feedback coil, and the current xy coordinate deviation can be obtained according to the port signal where the eddy current phenomenon occurs by labeling the feedback coil with the XY axis. Since the wireless charging efficiency will be reduced and slightly heated if it is turned on for a long time, the feedback system is only used for feedback adjustment when interference occurs in the positioning of the Bluetooth beacon 1 or there is an offset in the signal reflection. Due to the use of eddy current phenomenon feedback, its accuracy and reliability far exceed the current commonly used photoelectric sensor for vehicle body measurement.

[0032] Specifically, the feedback coils on the positioning plate 7 are numbered and arranged according to their positions, and then the current position of the receiving coil 2 is obtained and the offset direction is adjusted according to the current number of the reflux feedback.

[0033] The specific installation conditions at the parking lot are as follows: Figure 1 As shown, six stainless steel pillars are used and installed around the parking space in a surrounding distribution. The car is parked in the position with the receiving coil 2 installed according to the standard. The six RX receivers are used to build the XY coordinate system. The height of the two RX receivers in front of the car is higher than the height of the RX receivers on the left and right sides of the car body. The hardware part under the bottom of the car in the parking lot is divided into two layers, the upper layer is the positioning plate 7, and the lower layer is the transmitting coil 3.

[0034] The construction process of the rectangular coordinate system in the main control unit is as follows:

[0035] After the local hardware equipment is installed, there is no coordinate system and target positioning data after the first power-on. The installer carries a beacon broadcaster with him to start the broadcast signal at the transmitting coil end. After the 6 RX receivers receive the broadcast signal, they obtain the incident angle position through the above-mentioned Bluetooth AOA method and transmit the data to the ground control unit through modem. The ground control unit sends the data to the server (main control unit) to confirm whether all 6 RX receivers send data to the server through modem. If not, the server reports an error and shows that the receiver is abnormal. The server receives the data. After receiving the data uploaded by the ground control unit, the straight line where the two RX receivers at the front of the vehicle are located is the X-axis, the midpoint of the line segment formed by the two RX receivers is the zero point of the X-axis, the straight line where the two RX receivers on either side are located is the Y-axis, and the midpoint of the line segment formed by the two RX receivers is the origin of the Y-axis, thereby constructing an XY rectangular coordinate system; and locating the current transmitting coil 3, and storing the location of the beacon broadcast in the server, recording the location of the receiving coil 2, which is also the target point; the above is the construction of the XY coordinate system and the zero point and target coordinates.

[0036] After the construction is completed, the ground control unit connected to the server enters the standby state. The data sent by the ground control unit is a heartbeat packet to inform the server that the ground control unit is still working, but in an inactive state;

[0037] When a vehicle enters with a beacon, the broadcast sent by the beacon is received by the RX receiver, and the ground control unit is awakened from sleep mode. After waking up, it is necessary to determine whether it is a false trigger. This operation can be determined using the broadcast signal content and the receiving frequency. If it is a false trigger, it will continue to receive for 15 seconds and then enter sleep mode again. If it is not a false trigger, the receiving information will be refreshed at a high frequency and uploaded to the server to refresh the actual coordinates of the receiving coil. After the server calculates the actual coordinates of the receiving coil, it returns the navigation information to the ground control unit through algorithm calculation for use.

[0038] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A wireless charging alignment system for electric vehicles based on Bluetooth beacons, characterized in that: It includes a main control unit, a ground control unit connected to the main control unit for communication, a receiving coil and a Bluetooth beacon arranged on the car to be charged, and a transmitting coil and a communication receiver arranged in a parking lot. There are multiple groups of communication receivers, including a first group of communication receivers and a second group of communication receivers respectively located on the left and right sides of the car to be charged and a third group of communication receivers located on the front side of the car to be charged. The Bluetooth beacon is used to send out a broadcast signal, and the communication receiver is used to modulate and demodulate the received broadcast signal to form data and transmit it to the ground control unit, and the ground control unit transmits the data to the main control unit; the main control unit calculates and analyzes the received data to obtain the actual coordinates of the receiving coil, and then compares it with the target coordinates of the receiving coil previously stored and transmits the information back to the ground control unit, and the ground control unit regulates the receiving coil The relative position between the first group of communication receivers and the second group of communication receivers is installed at the same horizontal height, and the installation height of the third group of communication receivers is higher than the installation heights of the remaining two groups of communication receivers; the straight line where the two RX receivers in the third group of communication receivers are located is the X-axis, the midpoint of the line segment formed by the two RX receivers is the zero point of the X-axis, the straight line where the two RX receivers in the first group of communication receivers or the second group of communication receivers are located is the Y-axis, and the midpoint of the line segment formed by the two RX receivers is the origin of the Y-axis, thereby constructing a rectangular coordinate system; the charging alignment system also includes a positioning plate arranged in the parking lot, a feedback system is installed at the bottom of the positioning plate, and the transmitting coil is installed at the bottom of the positioning plate; the feedback system includes a plurality of feedback coils arranged in an array at the bottom of the positioning plate.

2. The electric vehicle wireless charging alignment system based on Bluetooth beacons according to claim 1 is characterized in that: The first group of communication receivers, the second group of communication receivers and the third group of communication receivers each include at least two communication receivers.

3. The electric vehicle wireless charging alignment system based on Bluetooth beacon according to claim 1 is characterized in that: The ground control unit and the main control unit are connected by 4G communication.

4. The alignment method of the electric vehicle wireless charging alignment system based on Bluetooth beacons according to any one of claims 1 to 3, characterized in that: The following steps are involved: 1) Install the hardware equipment locally, power it on after installation, and the operator carries the beacon broadcaster to the transmitting coil end to start the broadcast signal. After receiving the broadcast signal, the communication receiver modulates and demodulates the data and transmits it to the ground control unit. The ground control unit then sends the data to the main control unit, and the rectangular coordinate system is constructed in the main control unit. At the same time, the main control unit stores the coordinate value of the transmitting coil and the target coordinate of the receiving coil, and the ground control unit enters the sleep state; 2) The car to be charged drives into the parking lot, and the Bluetooth beacon installed on the car to be charged sends out a broadcast signal. After receiving the broadcast signal sent by the Bluetooth beacon, the communication receiver modulates and demodulates the data and transmits it to the ground control unit. The ground control unit determines whether the communication receiver is triggered by mistake based on the content of the broadcast signal and the frequency of receiving data. If it is a false trigger, it will continue to receive for 15 seconds and then enter the sleep state again; if it is not a false trigger, proceed to step 3); 3) The ground control unit refreshes the received data at a high frequency and sends the data to the main control unit. The main control unit calculates and analyzes the obtained data, determines the actual coordinates of the receiving coil, and compares it with the stored target coordinates of the receiving coil. The information is then sent back to the ground control unit, which controls the relative position between the receiving coil and the transmitting coil.

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