A microwave energy transmission and receiving end positioning method using space search strategy

Abstract

The present invention relates to the field of wireless energy transmission, and in particular to a method for positioning a microwave energy receiving end using a spatial search strategy, the method comprising the following steps: establishing a G-type guidance signal receiving antenna outside a guidance signal transmitting antenna to receive a radio frequency guidance signal sent by a receiving target; establishing a guidance signal receiving circuit to reduce the radio frequency signal to a baseband through a mixer while retaining the phase difference information of each receiving guidance signal, so as to facilitate sampling and analysis of the guidance signal; establishing a relationship between the conjugate phase difference of the received guidance signal and the position of the guidance signal transmitting point to form a spatial coordinate identification function of the receiving target; and determining the coordinates of the receiving target through a spatial search strategy. When positioning the receiving end, the present invention has low cost and strong anti-interference ability, and can reduce the number of guidance signal receiving antennas and their supporting radio frequency devices, and combined with a spatial search strategy, effectively solves the influence of phase ambiguity and phase error on the positioning result.

Description

Technical Field

[0001] The present invention relates to the field of wireless energy transmission, and in particular to a method for locating a microwave energy transmission and receiving end using a space search strategy. Background Art

[0002] Microwave wireless energy transmission technology uses microwaves as energy carriers to achieve wireless energy transmission from the energy supply end to the energy receiving end, breaking the constraints of traditional power supply that requires transmission cables or batteries. Microwave wireless energy transmission has incomparable advantages in areas where cables are not easy to install (lay) and batteries are not easy to replace. Microwave energy can be radiated into space through the transmitting antenna, and the receiving antenna at the energy receiving end can capture the microwave energy in space. However, the actual energy receiving antenna is limited in size and cannot capture all the microwave energy in space. Therefore, in order to improve the efficiency of the microwave energy transmission system, it is required to concentrate the microwave energy at the receiving antenna.

[0003] Most of the current microwave energy transmission experiments are demonstration experiments of microwave systems. The energy receiving target is placed in front of the transmitting antenna array, and the location information of the energy receiving target is known. However, in practical applications, the location of the energy receiving target is unknown, or only the approximate location range information is known. At this time, a set of energy receiving target positioning methods suitable for microwave energy transmission systems is needed. The traditional reverse beam control technology of embedding the guidance signal receiving antenna into the microwave energy transmitting antenna subarray is an effective way to solve this problem. However, when the scale of the transmitting antenna array is expanded, the corresponding guidance signal receiving system will also increase, which increases the complexity of the system and the cost. It is not suitable for large-scale microwave energy transmitting antenna arrays; and when the wave path difference between the guidance signal receiving antenna and the guidance signal transmitting point is greater than one wavelength, phase ambiguity will occur, making it difficult to obtain an accurate phase difference of the received guidance signal, affecting the positioning result. Summary of the invention

[0004] In view of the above problems, the present invention provides a method for locating a microwave energy transmission and receiving end using a spatial search strategy.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: the method comprises the following steps:

[0006] The guidance signal transmitting antenna and the guidance signal receiving antenna are arranged in a non-overlapping structure;

[0007] The degree of perception of the phase change of the received guidance signal caused by the relative position change of the energy receiving and transmitting ends by the guidance signal receiving antenna arrays of different structures;

[0008] Establishing a pilot signal receiving circuit;

[0009] Establish the relationship between the conjugate phase difference of the received guidance signal and the position of the guidance signal emission point to form the spatial coordinate identification function of the energy receiving target;

[0010] The coordinates of the energy target are determined through a spatial search strategy.

[0011] Preferably, a Γ-shaped guidance signal receiving antenna is established outside the guidance signal transmitting antenna to receive the radio frequency guidance signal sent by the powered target.

[0012] Preferably, the guidance signal receiving antenna is an antenna array composed of a plurality of receiving antennas.

[0013] Preferably, when establishing a pilot signal receiving circuit, while retaining the phase difference information of each received pilot signal, the RF signal is reduced to the baseband through a mixer to facilitate sampling and analysis of the pilot signal.

[0014] Preferably, the spatial search strategy specifically includes the following steps:

[0015] After receiving the guidance signal, obtaining the guidance signal phase difference;

[0016] After establishing the spatial coordinate identification function of the guidance signal emission point, determine the search range and search interval;

[0017] Performing a spatial coordinate search based on the obtained guidance signal phase difference and the determined search range and search interval;

[0018] Identify the coordinates of the guidance signal transmission.

[0019] In summary, the present invention has the following advantages:

[0020] The present invention proposes a method for locating a microwave energy receiving end using a space search strategy. When locating the receiving end, the method has low cost and strong anti-interference ability, and can reduce the number of guidance signal receiving antennas and their supporting radio frequency devices. Combined with the space search strategy, the method can effectively solve the influence of phase ambiguity and phase error on the positioning result. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The embodiment of the present invention provides Γ The structure diagram of the arrangement of the guidance signal receiving antenna;

[0022] Figure 2 is a flow chart of a spatial search strategy provided by an embodiment of the present invention;

[0023] Figure 3 The embodiment of the present invention provides x Axially arranged antenna receiving energy target in the case of phase difference change x Direction change comparison chart;

[0024] Figure 4 The embodiment of the present invention provides an example of an antenna arranged along the x-axis receiving the energy receiving target in the case of a phase difference change. y Change of direction;

[0025] Figure 5 The embodiment of the present invention provides x Axially arranged antenna receiving energy target in the case of phase difference change z Change of direction;

[0026] Figure 6 It is a diagram of a structure of seven receiving antennas without noise interference in the spatial search results of an energy receiving target provided by an embodiment of the present invention;

[0027] Figure 7 The spatial search results of the energy target provided by the embodiment of the present invention have noise interfering with 7 receiving antennas;

[0028] Figure 8 In the spatial search results of the energy receiving target provided by the embodiment of the present invention, there is noise interfering with 5 receiving antennas.

[0029] Numbers in the figure: 1, guidance signal transmitting antenna; 2, guidance signal receiving antenna. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0031] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but unless otherwise specified, these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first xx script may be referred to as a second xx script, and similarly, a second xx script may be referred to as a first xx script.

[0032] like Figure 1 As shown, the present invention provides a method for locating a microwave energy receiving end using a spatial search strategy, the method comprising the following steps:

[0033] The guidance signal transmitting antenna 1 and the guidance signal receiving antenna 2 are arranged in a non-overlapping manner;

[0034] The degree of perception of the phase change of the received guidance signal caused by the relative position change of the energy receiving and transmitting ends by the guidance signal receiving antenna arrays of different structures;

[0035] Establish a guidance signal receiving circuit, while retaining the phase difference information of each receiving guidance signal, reduce the RF signal to the baseband through a mixer to facilitate sampling and analysis of the guidance signal;

[0036] Establish the relationship between the conjugate phase difference of the received guidance signal and the position of the guidance signal emission point, that is, the position of the energy receiving target, and form the spatial coordinate identification function of the energy receiving target;

[0037] The coordinates of the energy target are determined through a spatial search strategy.

[0038] In the above steps, a Γ-shaped guidance signal receiving antenna 2 is established outside the guidance signal transmitting antenna 1; the guidance signal receiving antenna 2 is an antenna array composed of a plurality of receiving antennas, and the guidance signal transmitting point position is the energy receiving target position.

[0039] like Figure 2 As shown, the spatial search strategy in this embodiment specifically includes the following steps:

[0040] After receiving the guidance signal, obtaining the guidance signal phase difference;

[0041] After establishing the spatial coordinate identification function of the guidance signal emission point, determine the search range and search interval;

[0042] Performing a spatial coordinate search based on the obtained guidance signal phase difference and the determined search range and search interval;

[0043] Identify the coordinates of the guidance signal transmission.

[0044] like Figure 1 As shown, in the guidance signal receiving-transmitting antenna system of this embodiment, the guidance signal receiving array adopts a Γ-shaped structure; the x-direction and y-direction shared unit S 00 As a reference antenna; the spatial phase of the guidance signal in the propagation process lags as the propagation distance increases. Different guidance signal receiving antennas are at different distances from the guidance signal transmitting point. Due to different propagation distances, the received guidance signal phase is also different; when the wavelength of the guidance signal is λ, the unit S ym Relative reference unit S 00 The phase difference of the received pilot signal can be expressed as:

[0045]

[0046] The received phase difference reflects the phase delay of the guided signal caused by the wave path difference between the guided signal transmitting point and the guided signal receiving antenna. Therefore, if the conjugate phase difference of the received guided signal is used as the feeding phase of the guided signal receiving antenna, the phase delay difference of the signal radiated by each antenna unit to the guided signal transmitting point will be supplemented, and the phase of the signal at the guided signal transmitting point is the same, while the phases at other points in space are different; unit Sym The conjugate guidance signal of is propagated to the spatial search point (x, y, z) and the reference unit S 00 The phase difference of the conjugate pilot signal transmitted at this point can be expressed as:

[0047]

[0048] Calculate the phase difference between the conjugate pilot signal of each receiving antenna radiated from the antenna to the spatial search point and the conjugate pilot signal of the reference antenna radiated to the same spatial search point, and take the average of the absolute values ​​of the phase differences to have the following relationship:

[0049]

[0050] However, in practice, due to the existence of environmental noise and system errors, there is an error between the received phase difference of the guidance signal obtained by the receiving antenna array and the theoretical received phase difference of the guidance signal generated by the wave path difference. At this time, the phase difference between the signal propagated by the conjugate phase difference feed of the received guidance signal to the antenna unit and the signal propagated by the reference unit to the target point is approximately 0.

[0051] In order to improve the sensitivity of spatial search, the reciprocal logarithm of the above formula is used as the spatial coordinate search identification function of the guidance signal transmission point:

[0052]

[0053] like Figure 3 , Figure 4 , Figure 5 As shown, in this embodiment, 5 guidance signal receiving antennas are arranged along the x-axis, and the guidance signal receiving phase difference changes with the guidance signal transmitting point along the x, y, and z directions respectively; when the guidance signal transmitting point changes along the x direction, and the change direction is consistent with the arrangement direction of the guidance signal receiving antenna, the received guidance signal phase difference can produce an approximately linear change accordingly; when the guidance signal transmitting point changes along the y direction, the received guidance signal phase difference hardly changes; when the guidance signal transmitting point changes along the z direction, the larger the arrangement interval between the antennas, the more obvious the change in the received guidance signal phase difference; therefore, the guidance signal receiving antenna array using a Γ-shaped structure can locate the guidance signal transmitting points at different positions in the three-dimensional space.

[0054] In this embodiment, three groups of examples are set. In the examples, the frequency of the guidance signal is 2.9 GHz, and the coordinates of the guidance signal emission point are randomly set to x. f '=0.20m,y f '=0.30m,z f'=1.15m, the spacing between the guide signal receiving antennas is half the wavelength of the guide signal; the first group sets the guide signal receiving antenna array to arrange 7 antennas in a Γ-shaped structure, and sets it to an ideal situation with no phase error; the second group randomly generates a phase error within a range of 5°; the third group sets the guide signal receiving antenna array to arrange 5 antennas in a Γ-shaped structure, and randomly generates a phase error within a range of 5°; the three groups of examples are set at z=z f 'xoy plane search results such as Figure 6 , Figure 7 , Figure 8 shown.

[0055] By comparing the results of the first and second groups of examples, it can be concluded that: under ideal conditions, the spatial coordinate search and identification function of the energetic target is greater than 12dB at the position of the energetic target and less than 0dB at other points, which is consistent with the theoretical analysis; after simulating the interference of spatial noise and system errors on the receiving phase difference, the spatial coordinate search and identification function of the energetic target forms a maximum value at the transmission point of the guidance signal, and the coordinates of the energetic target can still be identified in the search space.

[0056] By comparing the results of the second and third groups of examples, it can be concluded that: under the random phase error caused by the same interference intensity, the antenna array with fewer guidance signal receiving antennas cannot correctly identify the position of the powered target due to the influence of the phase error, while the antenna array with more guidance signal receiving antennas can overcome the phase error and correctly identify the position of the powered target. This shows that adding guidance signal receiving antennas can effectively reduce the influence of spatial noise and system errors on the positioning results.

[0057] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for locating a microwave energy receiving end using a spatial search strategy, characterized in that: The method comprises the following steps: A guidance signal transmitting antenna (1) and a guidance signal receiving antenna (2) are arranged in a non-overlapping manner; The degree of perception of the phase change of the received guidance signal caused by the relative position change of the energy receiving and transmitting ends by the guidance signal receiving antenna arrays of different structures; Establishing a pilot signal receiving circuit; Establish the relationship between the conjugate phase difference of the received guidance signal and the position of the guidance signal emission point to form the spatial coordinate identification function of the energy receiving target; Determine the coordinates of the energy target through a spatial search strategy; The spatial search strategy specifically includes the following steps: After receiving the pilot signal, a pilot signal phase difference is obtained as a feeding phase of the pilot signal receiving antenna; After establishing the spatial coordinate identification function of the guidance signal emission point, determine the search range and search interval; Performing a spatial coordinate search based on the obtained guidance signal phase difference and the determined search range and search interval; Identify the guidance signal transmission coordinates; Calculate the phase difference between the conjugate pilot signal of each receiving antenna radiated from the antenna to the spatial search point and the conjugate pilot signal of the reference antenna radiated to the same spatial search point, and take the average of the absolute values ​​of the phase differences to have the following relationship: However, in practice, due to the presence of environmental noise and system errors, there is an error between the received phase difference of the guidance signal obtained by the receiving antenna array and the theoretical received phase difference of the guidance signal generated by the wave path difference. At this time, the phase difference between the signal propagated by the conjugate phase difference feed of the received guidance signal of the antenna unit and the signal propagated by the reference unit to the target point is approximately 0; In order to improve the sensitivity of spatial search, the reciprocal logarithm of the above formula is used as the spatial coordinate search identification function of the guidance signal transmission point: 。 2. A method for locating a microwave energy receiving end using a spatial search strategy according to claim 1, characterized in that: A Γ-shaped guidance signal receiving antenna (2) is established outside the guidance signal transmitting antenna (1) to receive the radio frequency guidance signal sent by the powered target.

3. A method for locating a microwave energy receiving end using a spatial search strategy according to claim 2, characterized in that: The guidance signal receiving antenna (2) is an antenna array composed of a plurality of receiving antennas.

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