Device for measuring azimuth angle of OBU

Abstract

The utility model discloses a device for measuring an azimuth angle of an OBU. The device comprises an array antenna, a power divider group, a phase shifter group, a combiner group, a power detection circuit and an MCU. The array antenna consists of a plurality of antenna units and is used for receiving microwave signals of the OBU; the power divider group is composed of a plurality of bisection power dividers, and each antenna unit is correspondingly connected with one bisection power divider; the phase shifter group consists of a plurality of phase shifters, is connected with the output ends of part of the power dividers, and is used for carrying out fixed phase delay on the output signals of the power dividers; the combiner group consists of a plurality of combiners, is connected with the output ends of the power dividers, and is used for combining output signals of the power dividers; the power detection circuit is connected with the power dividers and the combiner and is used for detecting a signal power value processed by the power divider group and the combiner group; and the MCU is connected with the power detection circuit and is used for acquiring a result of the power detection circuit and outputting an OBU azimuth angle. The problems that a DOA positioning scheme is complex in hardware and structure and high in equipment cost are solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to electronic nonstop charging (ETC) technical field, concretely relates to a device for measuring OBU azimuth. BACKGROUND

[0002] In the ETC charging system, the problem of adjacent lane interference is generally solved by adding a positioning module in the RSU device. The positioning module uses DOA technology to obtain the azimuth of the OBU, calculates the accurate position of the OBU according to the azimuth, and uses the positioning result to distinguish between adjacent lane vehicles and lane vehicles.

[0003] Prior art one: patent application number 201210008561.7 (OBU positioning method, positioning device and system based on DBF) gives an OBU positioning method and device based on DBF technology. This method uses DBF (conventional DOA) technology, multiple channels parallelly process the signals of the array antenna synchronously, converts the microwave signals into intermediate frequency signals, then performs digital down-conversion, calculates the autocorrelation matrix between all channels, obtains the azimuth of the OBU through power spectrum estimation algorithm, and calculates the two-dimensional coordinates of the OBU from multiple azimuths.

[0004] Prior art two: patent application number 202310503388.6 (OBU positioning device and positioning method based on double receiving channels) gives an OBU positioning method based on double receiving channels. This method optimizes the conventional DOA technology, only retains two down-conversion receiving channels, processes the selectable antenna elements of the array antenna in time-sharing mode, derives the autocorrelation matrix of the entire array antenna through the fixed reference channel, and then realizes OBU positioning.

[0005] Prior art three: patent application number 201410324090.X (method and device for calculating the incident direction angle of an on-board unit OBU) gives a direction angle calculation method. The method divides the signals received by the antenna elements, synthesizes the signals of adjacent antennas to obtain the synthesized signal amplitude V2, the signal amplitude before synthesis is V1, and calculates the phase difference of the signals of adjacent antennas The azimuth is calculated through the phase difference. Since the amplitude value cannot be negative, the final incident direction angle cannot be distinguished between left and right, i.e., this method cannot identify the two symmetrical targets on the normal line of the array antenna.

[0006] The DOA technology of the conventional and double receiving channels is based on the synchronous down-conversion reception of the software radio, and a high-speed signal processor and a power spectrum estimation algorithm are used to obtain the azimuth angle of the OBU, so as to complete accurate positioning. The advantage of this scheme is high positioning accuracy, good hardware universality, and many mature algorithms can be used. But the disadvantage is that the synchronous down-conversion and algorithm processing cannot be avoided, the hardware and structure are relatively complex, the cost is high, the performance requirement of the processor is relatively high, and it is not suitable for use in occasions such as the ETC parking lot which is sensitive to the equipment cost and does not require high positioning accuracy. SUMMARY

[0007] In view of the above technical problems, the utility model provides a device for measuring OBU azimuth angle, include:

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

[0009] The array antenna is composed of a plurality of antenna units, and the plurality of antenna units are arranged in sequence on a straight line; the array antenna is used for receiving the microwave signal of the OBU, and the spacing between the antenna units is half of the microwave signal of the OBU;

[0010] The power divider group is composed of a plurality of two-equal-division power dividers, and each antenna unit is connected with a two-equal-division power divider; each two-equal-division power divider receives the microwave signal of the antenna unit, and divides the microwave signal into two equal-power and equal-phase signals respectively;

[0011] The phase shifter group is composed of a plurality of phase shifters, and is connected with the output end of part of the power dividers, so as to perform fixed phase delay on the output signal of the power divider; then the output signal is sent to the connected power divider;

[0012] The combiner group is composed of a plurality of combiners, and is connected with the output end of the power divider, and is used for merging the output signal of the power divider;

[0013] The power detection circuit is connected with the power divider and the combiner, and is used for detecting the signal power value processed by the power divider group and the combiner group;

[0014] The MCU is connected with the power detection circuit, and is used for obtaining the result of the power detection circuit and outputting the azimuth angle of the OBU.

[0015] Further, the array antenna is composed of a plurality of antenna units, and specifically includes: four antenna units, which are respectively antenna (1), antenna (2), antenna (3) and antenna 4, and the received microwave signals are respectively S1, S2, S3 and S4; the spacing between the antenna (1) and the antenna (2) and the spacing between the antenna (3) and the antenna 4 are d, the spacing between the antenna (2) and the antenna (3) is d1, and when d=d1, the four antenna units form a one-dimensional uniform linear array.

[0016] Further, the power divider group is composed of multiple two-equal-division power dividers, each of which is connected to one two-equal-division power divider corresponding to one antenna unit, and specifically includes eight independent two-equal-division power dividers, wherein the power divider (11), the power divider (21), the power divider (31), and the power divider (41) are used to divide the signals received by the four antenna units into two equal-power and equal-phase signals respectively, thereby obtaining eight signals S11, S12, S21, S22, S31, S32, S41, and S42.

[0017] Further, the phase shifter group is composed of multiple phase shifters and is connected to the output ends of the partial power dividers to perform fixed-phase delay on the output signals of the power dividers, and includes:

[0018] The phase shifter (1) and the phase shifter (2) perform fixed-phase delay on S22 and S32 respectively After the phase delay, the signals S22D and S32D are obtained.

[0019] Further, the combiner group is composed of multiple combiners and is connected to the output ends of the power dividers to combine the output signals of the power dividers, and includes:

[0020] The combiner group is composed of one 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, and the power of S0 is P0.

[0022] Further, it further includes:

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

[0024] Further, it further includes:

[0025] The combiner (12) and the combiner (34) perform power addition and phase addition on S122, S222, S322, and S422 respectively to combine them into signals S12 and S34, and the corresponding powers are P12 and P34 respectively.

[0026] Further, the power detection circuit is used to detect the signal power values processed by the power divider group and the combiner group, and includes:

[0027] Power detection circuit, for detecting the power value of P1, P2, P3, P4, P0, P12, P34, and transmitting the detected power value to the MCU.

[0028] Further, it also includes:

[0029] The communication interface is used for realizing the communication with other modules of the RSU in the former controller, and outputs the azimuth angle and the positioning result.

[0030] Further, it also includes:

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

[0032] The device for measuring the OBU azimuth angle provided by the application utilizes the relationship between the microwave signal amplitude and the phase, detects the power size of the multi-path signal, converts the power size into the power coefficient, and then finds out the azimuth angle corresponding to the power coefficient through the lookup table method, so as to realize the OBU positioning, and the process of measuring the azimuth angle does not have a complex algorithm and has a low requirement on the processor performance, wherein the main components of the power divider, the phase shifter and the combiner are all realized by the PCB microstrip line, and the cost is low. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a device block diagram for measuring the OBU azimuth angle provided by the embodiment of the application;

[0034] Figure 2 is a device circuit diagram for measuring the OBU azimuth angle provided by the embodiment of the application. DETAILED DESCRIPTION

[0035] In the following description, many specific details are set forth in order to provide a thorough understanding of the application. However, the application can be practiced without the specific details, and it is understood that the application can be practiced with other than the described embodiments. Those skilled in the art will readily recognize from the disclosure herein, that the specific embodiments presented herein can be quite versatile and can be practiced in other ways than as specifically presented herein.

[0036] The application provides a device for measuring the OBU azimuth angle, which comprises 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. Figure 1 As shown in the device block diagram,

[0037] The array antenna is composed of a plurality of antenna units, and the plurality of antenna units are arranged in sequence on a straight line; the array antenna is used for receiving the microwave signal of the OBU, and the distance between the antenna units is half of the OBU microwave signal.

[0038] 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; each two-equal-division power divider receives the microwave signal of the antenna unit and divides the microwave signal into two equal-power and equal-phase signals respectively;

[0039] The phase shifter group is composed of multiple phase shifters and is connected with the output end of the partial power divider to perform fixed phase delay on the output signal of the power divider; then the output signal is sent to the connected power divider;

[0040] The combiner group is composed of multiple combiners and is connected with the output end of the power divider to combine the output signals of the power dividers;

[0041] The power detection circuit is connected with the power divider and the combiner and is used to detect the signal power value processed by the power divider group and the combiner group;

[0042] The MCU is connected with the power detection circuit and is used to obtain the result of the power detection circuit and output the azimuth angle of the OBU.

[0043] Figure 2 In the embodiment, the OBU emits signals to the array antenna from the θ angle direction, and since the distance from the OBU to the array antenna is much larger than the distance between the antenna units, it can be considered that the signals are parallelly incident to each antenna unit, i.e., the direction angles of all the antenna units are the same.

[0044] The array antenna is composed of multiple antenna units and specifically includes four antenna units, i.e., antenna (1), antenna (2), antenna (3) and antenna 4, and the received microwave signals are S1, S2, S3 and S4 respectively; the distance between antenna (1) and antenna (2) and the distance between antenna (3) and antenna 4 are d, and the distance between antenna (2) and antenna (3) is d1; when d=d1, the four antenna units form a one-dimensional uniform linear array, and the distance between the four antenna units is about half of the wavelength of the microwave signal of the OBU, i.e., about 26 mm.

[0045] 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, specifically including eight independent two-equal-division power dividers, wherein the power divider (11), the power divider (21), the power divider (31) and the 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.

[0046] The phase shifter (1) and the phase shifter (2) perform fixed phase delay on S22 and S32 respectively After the phase delay, the signals S22D and S32D are obtained.

[0047] The combiner group is composed of a 4-output combiner and two 2-input combiners;

[0048] The 4-input combiner is used for combining the four signals S11, S21, S31 and S41 to obtain a new signal S0, and the power of S0 is P0.

[0049] The power dividers (12), (22), (32) and (42) are used for dividing the signals S12, S22D, S32D and S42 into two equal-power and equal-phase signals respectively, and eight signals S121, S122, S221, S222, S321, S322, S421 and S422 are obtained, wherein the powers of S121, S221, S321 and S421 are P1, P2, P3 and P4 respectively.

[0050] The combiners (12) and (34) are used for power adding and phase combining the signals S122, S222, S322 and S422 into signals S12 and S34 respectively, and the corresponding powers are P12 and P34.

[0051] The power detection circuit is used for detecting the power values of P1, P2, P3, P4, P0 and P12, P34, and transmitting the detected power values to the MCU.

[0052] The communication interface is used for realizing the communication with other modules of the RSU through the MCU, and outputting the azimuth angle and the positioning result.

[0053] The memory is used for storing the power coefficients and the corresponding incident azimuth angles.

[0054] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system or a computer program product. Therefore, the present application can adopt a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware aspects. Moreover, the present application can adopt a computer program product implemented on one or more computer usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program codes.

[0055] The present application is described with reference to flowcharts and / or block diagrams of the method, device (system) and computer program product according to the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be realized by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device realize the functions described in the flows and / or blocks in the flowcharts and / or block diagrams.Figure 1 apparatuses that implement the functions specified in the flowchart Figure 1

[0056] 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 which implement the flowchart Figure 1 apparatuses that implement the functions specified in the flowchart Figure 1

[0057] 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 that are executed on the computer or other programmable apparatus provide steps for implementing the flowchart Figure 1 apparatuses that implement the functions specified in the flowchart Figure 1

[0058] Finally, it should be noted that the above-mentioned embodiments are merely used to illustrate the technical solutions of the present application, rather than limit the technical solutions of the present application. Although the present application has been described in detail with reference to the above-mentioned embodiments, those skilled in the art should understand that the specific embodiments of the present application can be modified or replaced equivalently without departing from the spirit and scope of the present application, and any modification or equivalent replacement without departing from the spirit and scope of the present application should be covered in the scope of the claims of the present application.​​​

Claims

1. A device for measuring the azimuth angle of an OBU, characterized in that, Comprise: Array antenna, power divider group, phase shifter group, combiner group, power detection circuit, MCU, storage chip, communication interface; Array antenna, composed of a plurality of antenna units, a plurality of antenna units are arranged in a straight line; Array antenna for receiving OBU microwave signal, antenna unit spacing is half of the OBU microwave signal; Power divider group, composed of a plurality of two equal power dividers, each antenna unit is connected with a two equal power divider; each two equal power divider receives the microwave signal of the antenna unit, and divides the microwave signal into two equal power and phase signals respectively; Phase shifter group, composed of a plurality of phase shifters, connected with the output end of part of the power divider, the output signal of the power divider is fixed phase delay; Then the output signal is sent to the connected power divider; Combiner group, composed of a plurality of combiners, connected with the output end of the power divider, used for combining the output signal of the power divider; Power detection circuit, connected with the power divider and the combiner, used for detecting the signal power value processed by the power divider group and the combiner group; MCU, connected with the power detection circuit, used for obtaining the result of the power detection circuit and outputting the azimuth angle of OBU.

2. The apparatus of claim 1, wherein, Array antenna, composed of a plurality of antenna units, specifically comprising: four antenna units, respectively antenna (1), antenna (2), antenna (3), antenna 4, the received microwave signal is S1, S2, S3, S4 respectively; the distance between antenna (1) and antenna (2) and the distance between antenna (3) and antenna 4 is d, the distance between antenna (2) and antenna (3) is d1, when d = d1, the four antenna units form a one-dimensional uniform linear array.

3. The apparatus of claim 1, wherein, Power divider group, composed of a plurality of two equal power dividers, each antenna unit is connected with a two equal power divider, specifically comprising: eight independent two equal power dividers, wherein, power divider (11), power divider (21), power divider (31), power divider (41), used for dividing the signals received by the four antenna units into two equal power and phase signals, obtaining eight signals S11, S12, S21, S22, S31, S32, S41, S42.

4. The apparatus of claim 1, wherein, Phase shifter group, composed of a plurality of phase shifters, connected with the output end of part of the power divider, the output signal of the power divider is fixed phase delay, comprising: The phase shifter (1) and the phase shifter (2) respectively fix the phase delay φ of S22, S32 Δ After the phase delay, the signals S22D, S32D are obtained.

5. The apparatus of claim 1, wherein, Combiner group, composed of a plurality of combiners, connected with the output end of the power divider, used for combining the output signal of the power divider, comprising: Combiner group, composed of a 4 output combiner and two 2 input combiners; 4 input combiner, used for combining S11, S21, S31, S41 four signals to obtain a new signal S0, the power of S0 is P0.

6. The apparatus of claim 1, wherein, Also comprising: The power divider (12), the power divider (22), the power divider (32), the power divider (42) are used for dividing the S12, S22D, S32D, S42 signals into two equal power and phase signals respectively, obtaining eight signals S121, S122, S221, S222, S321, S322, S421, S422, wherein the powers of S121, S221, S321, S421 are P1, P2, P3, P4 respectively.

7. The apparatus of claim 1, wherein, Further comprising: The combiner (12), the combiner (34) respectively add the powers and phases of S122, S222, S322, S422 to combine them into signals S12, S34, and the corresponding powers are P12, P34 respectively.

8. The apparatus of claim 1, wherein, The power detection circuit is used for detecting the power value of the signal processed by the power divider group and the combiner group, comprising: The power detection circuit is used for detecting the power value of P1, P2, P3, P4, P0, P12, P34, and transmitting the detected power value to the MCU.

9. The apparatus of claim 1, wherein, Further comprising: The communication interface is used for realizing the communication with other modules of the RSU in the form of the former controller, outputting the azimuth angle and the positioning result.

10. The apparatus of claim 1, wherein, Further comprising: The memory is used for storing the power coefficient and the corresponding incident azimuth angle.

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