A device and method for measuring an OBU azimuth angle

Abstract

The application discloses a device and method for measuring OBU azimuth angle, comprising: an array antenna, a power divider group, a phase shifter group, a combiner group, a power detection circuit, an MCU; the array antenna is composed of multiple antenna units and is used for receiving microwave signals of the OBU; the power divider group is composed of multiple two-equal-division power dividers, and each antenna unit is connected with a two-equal-division power divider; the phase shifter group is composed of multiple phase shifters and is used for fixedly delaying the output signals of the power dividers; the combiner group is composed of multiple combiners, is connected with the output ends of the power dividers and is used for combining the output signals of the power dividers; the power detection circuit is connected with the power dividers and the combiners and is used for detecting the signal power values processed by the power divider group and the combiner group; the MCU is connected with the power detection circuit, is used for acquiring the results of the power detection circuit and is used for outputting the OBU azimuth angle. The problems of complex hardware and structure and high equipment cost of the DOA positioning scheme are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic toll collection (ETC), and in particular to a device and method for measuring an OBU azimuth. Background Art

[0002] In ETC toll collection systems, adjacent lane interference and other issues are typically addressed by adding a positioning module to the RSU. This module uses technologies such as Direction of Arrival (DOA) to obtain the OBU's azimuth, calculates its precise position based on the azimuth, and uses the positioning results to distinguish vehicles in adjacent lanes from those in the vehicle's own lane.

[0003] Prior art 1: Patent application number 201210008561.7 (DBF-based OBU positioning method, positioning device and system) provides an OBU positioning method and device based on DBF technology. This method adopts DBF (conventional DOA) technology, and multiple channels synchronously process the signals of the array antenna in parallel, convert the microwave signal into an intermediate frequency signal and then perform digital down-conversion, calculate the autocorrelation matrix between all channels, obtain the azimuth of the OBU through the power spectrum estimation algorithm, and calculate the two-dimensional coordinates of the OBU from multiple azimuths.

[0004] Prior art 2: Patent application number 202310503388.6 (An OBU positioning device and positioning method based on dual receiving channels) provides an OBU positioning method with dual receiving channels. This method optimizes the conventional DOA technology, retains only two down-conversion receiving channels, and time-shares the optional antenna units of the array antenna. The autocorrelation matrix of the entire array antenna is restored through a fixed reference channel to achieve OBU positioning.

[0005] Prior Art 3: Patent application No. 201410324090.X (A method and device for calculating the incident angle of an onboard unit OBU) provides a method for calculating the direction angle, which performs power division on the received signal of the antenna unit, synthesizes the signals of adjacent antennas, obtains the synthesized signal amplitude V2, and the signal amplitude before synthesis is V1, and calculates the phase difference of the adjacent antenna signals. The azimuth angle is calculated by the phase difference. Since the amplitude value cannot be negative, the resulting incident direction angle cannot distinguish between left and right. In other words, this method cannot identify two symmetrical targets on the left and right of the array antenna normal.

[0006] Both conventional and dual-receive-channel DOA technologies are based on software-defined radio synchronous down-conversion reception. They employ high-speed signal processors and power spectrum estimation algorithms to determine the OBU's azimuth angle, thereby achieving precise positioning. The advantages of this approach include high positioning accuracy, hardware versatility, and the availability of a wide range of mature algorithms. However, the disadvantages are that both methods require synchronous down-conversion and algorithm processing, resulting in complex hardware and architecture, high cost, and high processor performance requirements. This makes them less suitable for applications where positioning accuracy is less critical but equipment cost is a concern, such as ETC parking lots. Summary of the Invention

[0007] In view of the above technical problems, the present invention provides a device and method for measuring the azimuth of an OBU, the method comprising:

[0008] Including: array antenna, power divider group, phase shifter group, combiner group, power detection circuit, MCU;

[0009] The array antenna consists of multiple antenna units arranged in a straight line. The array antenna is used to receive microwave signals from the OBU. The spacing between the antenna units is half the spacing of the OBU microwave signal.

[0010] A power splitter group is composed of multiple bisection power splitters, each antenna unit is connected to a bisection power splitter; each bisection power splitter receives the microwave signal of the antenna unit and splits the microwave signal into two equal power and equal phase signals;

[0011] A phase shifter group, consisting of multiple phase shifters, is connected to the output end of some power splitters to delay the output signal of the power splitter with a fixed phase; and then sends the output signal to the connected power splitter;

[0012] A combiner group, consisting of multiple combiners, is connected to the output end of the power divider and is used to combine the output signals of the power divider;

[0013] A power detection circuit is connected to the power splitter and combiner to detect the power value of the signal after being processed by the power splitter group and the combiner group;

[0014] The MCU is connected to the power detection circuit and is used to obtain the result of the power detection circuit and output the OBU azimuth.

[0015] Furthermore, the array antenna is composed of multiple antenna units, specifically including: four antenna units, namely antenna 1, antenna 2, antenna 3, and antenna 4, and the received microwave signals are S1, S2, S3, and S4 respectively; the spacing between antenna 1 and antenna 2, antenna 3 and antenna 4 is d, and the spacing between antenna 2 and antenna 3 is d1. When d=d1, the four antenna units form a one-dimensional uniform linear array.

[0016] Furthermore, the power divider group is composed of multiple two-way power dividers, and each antenna unit is connected to a corresponding two-way power divider, specifically including: 8 independent two-way power dividers, among which power divider 11, power divider 21, power divider 31, and power divider 41 are used to divide the signals received by the four antenna units into two equal-power and equal-phase signals, respectively, to obtain eight signals S11, S12, S21, S22, S31, S32, S41, and S42.

[0017] Furthermore, a phase shifter group, consisting of a plurality of phase shifters, is connected to the output end of some power dividers to perform a fixed phase delay on the output signal of the power divider, including:

[0018] Phase shifter 1 and phase shifter 2 respectively delay S22 and S32 by a fixed phase. After phase delay, signals S22D and S32D are obtained.

[0019] Furthermore, a combiner group, consisting of a plurality of combiners, is connected to the output end of the power splitter and is used to combine the output signals of the power splitter, including:

[0020] Combiner group, consisting of a 4-output combiner and two 2-input combiners;

[0021] The 4-input combiner is used to combine the four signals S11, S21, S31, and S41 to obtain a new signal S0, where the power of S0 is P0.

[0022] Furthermore, it also includes:

[0023] Power divider 12, power divider 22, power divider 32, and power divider 42 are used to divide the S12, S22D, S32D, and S42 signals into two signals of equal power and equal phase, respectively, to obtain eight signals S121, S122, S221, S222, S321, S322, S421, and S422, where the powers of S121, S221, S321, and S421 are P1, P2, P3, and P4, respectively.

[0024] Furthermore, it also includes:

[0025] Combiner 12 and combiner 34 perform power addition on S122, S222, S322, and S422, respectively, and combine them into signals S12 and S34, with corresponding powers of P12 and P34, respectively.

[0026] Furthermore, the power detection circuit is used to detect the power value of the signal after being processed by the power splitter group and the combiner group, including:

[0027] The power detection circuit is used to detect the power values ​​of P1, P2, P3, P4, P0, P12, and P34, and transmit the detected power values ​​to the MCU.

[0028] Furthermore, it also includes:

[0029] Communication interface, used to communicate with other modules and controllers of RSU, and output azimuth and positioning results.

[0030] Furthermore, it also includes:

[0031] The memory is used to store the power coefficient and the corresponding incident azimuth angle.

[0032] A method for testing and measuring an OBU azimuth, comprising:

[0033] Determine the theoretical power coefficient curve corresponding to the phase angle based on the spacing between antenna units and the phase delay value of the phase shifter;

[0034] When a vehicle passes through the gate, the OBU signal received by the positioning module is used to detect multiple power values ​​passing through the combiner and power splitter;

[0035] Calculate the power coefficient corresponding to the OBU according to the multiple power values;

[0036] The OBU azimuth is determined based on the power coefficient and the theoretical power coefficient curve.

[0037] Furthermore, according to the spacing between the antenna units and the phase delay value of the phase shifter, a theoretical power coefficient curve corresponding to the phase angle is determined, including:

[0038] According to the spacing d, d1 of the antenna units and the phase delay value of the phase shifter Calculate the theoretical power coefficient K1 and K2 curves within the phase angle θ∈[0,180] range, and save the theoretical power coefficients into the power coefficient table.

[0039] Furthermore, multiple power values ​​passing through the combiner and the power splitter are detected, including:

[0040] Power values ​​P1, P2, P3, P4, P0, P12, P34.

[0041] Further, according to the multiple power values, the power coefficient corresponding to the OBU is calculated, including:

[0042] Calculate the average power Pa, Pa = (P1 + P2 + P3 + P4) / 4;

[0043] Calculate the power coefficient corresponding to the OBU, K1 = P0 / Pa, K2 = (P12-P34) / Pa.

[0044] Further, according to the power coefficient and the theoretical power coefficient curve, the OBU azimuth is determined, including:

[0045] According to the values ​​of power coefficients K1 and K2, find the corresponding azimuth angle θ from the power coefficient table;

[0046] Take the azimuth angles in two directions to calculate the coordinates of the OBU and output them.

[0047] The present invention provides a device and method for measuring the azimuth of an OBU (on-board unit) (OBU). The device utilizes the relationship between microwave signal amplitude and phase to detect the power of multiple signals, converts the power into a power coefficient, and then uses a lookup table to find the azimuth corresponding to the power coefficient, thereby locating the OBU. The azimuth measurement process does not require complex algorithms and does not require high processor performance. Its main components, including the power divider, phase shifter, and combiner, are all implemented using PCB microstrip lines, resulting in low cost. This device aims to address the complex hardware and structure and high equipment costs of conventional DOA positioning solutions, and to address ETC toll collection scenarios where positioning accuracy is not required and the application environment is relatively simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 1 is a block diagram of a device for measuring an OBU azimuth provided by an embodiment of the present invention;

[0049] Figure 2 1 is a circuit diagram of a device for measuring an OBU azimuth provided by an embodiment of the present invention;

[0050] Figure 3 1 is a flow chart of a method for testing an OBU azimuth provided by an embodiment of the present invention;

[0051] Figure 4 1 is a curve showing the relationship between power coefficient and azimuth angle provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0052] The following description sets forth numerous specific details to facilitate a thorough understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar generalizations without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific implementations disclosed below.

[0053] The present invention proposes a device for measuring the azimuth of an OBU, comprising: an array antenna, a power divider group, a phase shifter group, a combiner group, a power detection circuit, an MCU, a memory chip, and a communication interface; the device block diagram is shown in FIG. Figure 1 As shown,

[0054] The array antenna consists of multiple antenna units arranged in a straight line. The array antenna is used to receive microwave signals from the OBU. The spacing between the antenna units is half the spacing of the OBU microwave signal.

[0055] A power splitter group is composed of multiple bisection power splitters, each antenna unit is connected to a bisection power splitter; each bisection power splitter receives the microwave signal of the antenna unit and splits the microwave signal into two equal power and equal phase signals;

[0056] A phase shifter group, consisting of multiple phase shifters, is connected to the output end of some power splitters to delay the output signal of the power splitter with a fixed phase; and then sends the output signal to the connected power splitter;

[0057] A combiner group, consisting of multiple combiners, is connected to the output end of the power divider and is used to combine the output signals of the power divider;

[0058] A power detection circuit is connected to the power splitter and combiner to detect the power value of the signal after being processed by the power splitter group and the combiner group;

[0059] The MCU is connected to the power detection circuit and is used to obtain the result of the power detection circuit and output the OBU azimuth.

[0060] Figure 2 In the figure, the OBU transmits the signal to the array antenna from the angle θ. Since the distance between the OBU and the array antenna is much greater than the distance between the antenna units, it can be considered that the signal is incident on each antenna unit in parallel, that is, the direction angle of all antenna units is the same.

[0061] The array antenna consists of multiple antenna units, specifically: four antenna units, namely antenna 1, antenna 2, antenna 3, and antenna 4, and the received microwave signals are S1, S2, S3, and S4 respectively; the spacing between antenna 1 and antenna 2, antenna 3 and antenna 4 is d, and the spacing between antenna 2 and antenna 3 is d1. When d=d1, the four antenna units form a one-dimensional uniform linear array. The spacing between the four antenna units is approximately half the wavelength of the OBU microwave signal, that is, about 26 mm.

[0062] The power splitter group is composed of multiple 2-way power splitters, and each antenna unit is connected to a 2-way power splitter, specifically including: 8 independent 2-way power splitters, among which power splitter 11, power splitter 21, power splitter 31, and power splitter 41 are used to split the signals received by the four antenna units into two equal-power and equal-phase signals, respectively, to obtain eight signals S11, S12, S21, S22, S31, S32, S41, and S42.

[0063] Phase shifter 1 and phase shifter 2 respectively delay S22 and S32 by a fixed phase. After phase delay, signals S22D and S32D are obtained.

[0064] Combiner group, consisting of a 4-output combiner and two 2-input combiners;

[0065] The 4-input combiner is used to combine the four signals S11, S21, S31, and S41 to obtain a new signal S0, where the power of S0 is P0.

[0066] Power divider 12, power divider 22, power divider 32, and power divider 42 are used to divide the S12, S22D, S32D, and S42 signals into two signals of equal power and equal phase, respectively, to obtain eight signals S121, S122, S221, S222, S321, S322, S421, and S422, where the powers of S121, S221, S321, and S421 are P1, P2, P3, and P4, respectively.

[0067] Combiner 12 and combiner 34 perform power addition on S122, S222, S322, and S422, respectively, and combine them into signals S12 and S34, with corresponding powers of P12 and P34, respectively.

[0068] The power detection circuit is used to detect the power values ​​of P1, P2, P3, P4, P0, P12, and P34, and transmit the detected power values ​​to the MCU.

[0069] Communication interface, used to communicate with other modules and controllers of RSU, and output azimuth and positioning results.

[0070] The memory is used to store the power coefficient and the corresponding incident azimuth angle.

[0071] The present invention also provides a method for testing the OBU azimuth, such as Figure 3 As shown. It includes the following steps:

[0072] Determine the theoretical power coefficient curve corresponding to the phase angle based on the spacing between antenna units and the phase delay value of the phase shifter;

[0073] When a vehicle passes through the gate, the OBU signal received by the positioning module is used to detect multiple power values ​​passing through the combiner and power splitter;

[0074] Calculate the power coefficient corresponding to the OBU according to the multiple power values;

[0075] The OBU azimuth is determined based on the power coefficient and the theoretical power coefficient curve.

[0076] Furthermore, according to the spacing between the antenna units and the phase delay value of the phase shifter, a theoretical power coefficient curve corresponding to the phase angle is determined, including:

[0077] According to the spacing d, d1 of the antenna units and the phase delay value of the phase shifter Calculate the theoretical power coefficient K1 and K2 curves within the phase angle θ∈[0,180] range, and save the theoretical power coefficients into the power coefficient table.

[0078] Furthermore, multiple power values ​​passing through the combiner and the power splitter are detected, including:

[0079] Power values ​​P1, P2, P3, P4, P0, P12, P34.

[0080] Further, according to the multiple power values, the power coefficient corresponding to the OBU is calculated, including:

[0081] Calculate the average power Pa, Pa = (P1 + P2 + P3 + P4) / 4;

[0082] Calculate the power coefficient corresponding to the OBU, K1 = P0 / Pa, K2 = (P12-P34) / Pa.

[0083] Further, according to the power coefficient and the theoretical power coefficient curve, the OBU azimuth is determined, including:

[0084] According to the values ​​of power coefficients K1 and K2, find the corresponding azimuth angle θ from the power coefficient table;

[0085] Take the azimuth angles in two directions to calculate the coordinates of the OBU and output them.

[0086] The principle of calculating azimuth angle from power value is as follows: Since the antenna units are very close together, the distance from the OBU to the antenna is much greater than the distance between the antenna units. Therefore, the signal power received by the antenna units is equal, and the phase difference is only related to the OBU incident azimuth angle θ. The OBU transmits a microwave signal in the direction of θ with a signal wavelength of λ. If the power received by each antenna unit is P, the power obtained after passing through the power splitter, phase shifter, and combiner in the figure satisfies the following relationship:

[0087]

[0088] Let K1 and K2 be power coefficients, and K1 = P0 / P1, K2 = (P12-P34) / P1, then we have

[0089]

[0090] When d=d1=λ / 2, When, the relationship between K1, K2 and θ is

[0091]

[0092] K2 = 2 sin (π cos θ)

[0093] That is, when the array antenna is a one-dimensional uniform linear array with a spacing of λ / 2 and the phase shifter delay is 90°, the corresponding power coefficient versus the incident azimuth angle curve is shown in FIG. 4.

[0094] Those skilled in the art will appreciate that embodiments of the present application can be readily used as a method, apparatus, or computer program product. Accordingly, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application can take the form of a computer program product on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage devices, etc.) embodying computer readable program code.

[0095] The present application is described in reference to the flowchart and / or block diagrams of the method, apparatus (system) and computer program product according to embodiments of the present application. It is understood that each flow and / or block in the flowchart and / or block diagrams, and a combination of flows and / or blocks in the flowchart and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general purpose computer, a special purpose computer, an embedded processor or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart and / or block diagrams block or blocks. Figure 1 one or more flows and / or blocks Figure 1 means for carrying out the function specified in the flowchart and / or block diagram block or blocks.

[0096] These computer program instructions can also be stored in a computer- readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions means which implement the function specified in the flowchart and / or block diagrams block or blocks. Figure 1 one or more flows and / or blocks Figure 1 means for carrying out the function specified in the flowchart and / or block diagram block or blocks.

[0097] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart and / or block diagrams block or blocks. Figure 1 one or more flows and / or blocks Figure 1 means for carrying out the function specified in the flowchart and / or block diagram block or blocks.

[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modifications or equivalents that do not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A device for measuring the azimuth of an OBU, characterized in that: include: Array antenna, power divider group, phase shifter group, combiner group, power detection circuit, MCU; Array antenna, composed of multiple antenna units, which are arranged in a straight line; The array antenna is used to receive the microwave signal from the OBU, and the spacing between antenna elements is half of the OBU microwave signal; The power splitter group is composed of multiple bisection power splitters, and each antenna unit is connected to a bisection power splitter; The phase shifter group is composed of multiple phase shifters and is connected to the output end of some power dividers to delay the output signal of the power divider with a fixed phase; The output signal is then sent to the connected power splitter; A combiner group, consisting of multiple combiners, is connected to the output end of the power divider and is used to combine the output signals of the power divider; A power detection circuit is connected to the power splitter and combiner to detect the power value of the signal after being processed by the power splitter group and the combiner group; MCU, connected to the power detection circuit, for obtaining the result of the power detection circuit, calculating the power coefficient corresponding to the OBU according to multiple signal power values; determining the OBU azimuth according to the power coefficient and the theoretical power coefficient curve, and outputting the OBU azimuth; A power splitter group, consisting of multiple 2-way power splitters, with each antenna unit correspondingly connected to a 2-way power splitter, specifically including: 8 independent 2-way power splitters, among which power splitter 11, power splitter 21, power splitter 31, and power splitter 41 are used to split the signals received by the four antenna units into two equal-power and equal-phase signals, respectively, to obtain eight signals S11, S12, S21, S22, S31, S32, S41, and S42; The phase shifter group, consisting of multiple phase shifters, is connected to the output end of some power dividers to delay the output signal of the power divider with a fixed phase, including: Phase shifter 1 and phase shifter 2 respectively delay S22 and S32 by a fixed phase of φ Δ , after phase delay, signals S22D and S32D are obtained; The combiner group, consisting of multiple combiners, is connected to the output end of the power splitter and is used to combine the output signals of the power splitter, including: Combiner group, consisting of a 4-input combiner and two 2-input combiners; The 4-input combiner is used to combine the four signals S11, S21, S31, and S41 to obtain a new signal S0, and the power of S0 is P0; Power dividers 12, 22, 32, and 42 are configured to divide signals S12, S22D, S32D, and S42 into two equal-power and equal-phase signals, respectively, to obtain eight signals S121, S122, S221, S222, S321, S322, S421, and S422, where the powers of S121, S221, S321, and S421 are P1, P2, P3, and P4, respectively. Combiner 12 adds the power of S122 and S222 to form a signal S12 with a corresponding power of P12; combiner 34 adds the power of S322 and S422 to form a signal S34 with a corresponding power of P34.

2. The device according to claim 1, characterized in that The array antenna is composed of multiple antenna units, specifically including: four antenna units, namely antenna 1, antenna 2, antenna 3, and antenna 4, and the received microwave signals are S1, S2, S3, and S4 respectively; the spacing between antenna 1 and antenna 2, antenna 3 and antenna 4 is d, and the spacing between antenna 2 and antenna 3 is d1. When d=d1, the four antenna units form a one-dimensional uniform linear array.

3. The device according to claim 1, characterized in that The power detection circuit is used to detect the signal power value after being processed by the power splitter group and the combiner group, including: The power detection circuit is used to detect the power values ​​of P1, P2, P3, P4, P0, P12, and P34, and transmit the detected power values ​​to the MCU.

4. The device according to claim 1, characterized in that Also includes: Communication interface, used to communicate with other modules and controllers of RSU, and output azimuth and positioning results.

5. The device according to claim 1, characterized in that Also includes: The memory is used to store the power coefficient and the corresponding incident azimuth angle.

6. A method for measuring the azimuth of an OBU using the device according to any one of claims 1 to 5, characterized in that: include: Determine the theoretical power coefficient curve corresponding to the phase angle based on the spacing between antenna units and the phase delay value of the phase shifter; When a vehicle passes through the gate, the OBU signal received by the positioning module is used to detect multiple power values ​​passing through the combiner and power splitter; Calculate the power coefficient corresponding to the OBU according to the multiple power values; The OBU azimuth is determined based on the power coefficient and the theoretical power coefficient curve.

7. The method according to claim 6, characterized in that Based on the spacing between antenna elements and the phase shifter phase delay value, determine the theoretical power coefficient curve corresponding to the phase angle, including: According to the spacing d, d1 of the antenna units and the phase delay value of the phase shifter Calculate the theoretical power coefficient K1 and K2 curves within the phase angle θ∈[0,180] range, and save the theoretical power coefficient to the power coefficient table; The array antenna is composed of multiple antenna units, specifically including: four antenna units, namely antenna 1, antenna 2, antenna 3, and antenna 4, and the received microwave signals are S1, S2, S3, and S4 respectively; the spacing between antenna 1 and antenna 2, antenna 3 and antenna 4 is d, and the spacing between antenna 2 and antenna 3 is d1. When d=d1, the four antenna units form a one-dimensional uniform linear array.

8. The method according to claim 6, characterized in that Detects multiple power levels through combiners and splitters, including: Power values ​​P1, P2, P3, P4, P0, P12, P34.

9. The method according to claim 6, characterized in that Calculating the power coefficient corresponding to the OBU according to the multiple power values ​​includes: Calculate the average power Pa, Pa = (P1 + P2 + P3 + P4) / 4; Calculate the power coefficient corresponding to the OBU, K1 = P0 / Pa, K2 = (P12-P34) / Pa.

10. The method according to claim 6, characterized in that Determine the OBU azimuth according to the power coefficient and the theoretical power coefficient curve, including: According to the values ​​of power coefficients K1 and K2, find the corresponding azimuth angle θ from the power coefficient table; Take the azimuth angles in two directions to calculate the coordinates of the OBU and output them.

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