Mechanically dynamically adjustable electromagnetic wave reflecting surface unit and array reflecting surface

Abstract

The present invention discloses a mechanically dynamically adjustable electromagnetic wave reflecting surface unit and an array-type reflecting surface, which belong to the field of wireless communication. The reflecting surface unit includes an outer frame, an inner frame, a reflecting sheet, an outer steering gear, an inner steering gear, an outer gear set and an inner gear set; the outer steering gear is connected to the outer gear, which is used to drive the inner frame to rotate, and the rotation of the inner frame will drive the reflecting sheet to rotate; the inner steering gear is connected to the inner gear, which is used to drive the reflecting sheet to rotate; the movements of the outer steering gear and the inner steering gear do not interfere with each other, so that the reflecting sheet has two degrees of freedom of rotation, that is, rotation around two mutually perpendicular axes, horizontal and vertical. A plurality of reflecting surface units are closely arranged around the outer frame to form an array-type reflecting surface. By adjusting the angles of multiple reflecting surface units, the reflection direction and projection trajectory of electromagnetic waves are changed, and the effect of the antenna array of the traditional circuit structure is achieved with a non-circuit structure, reducing the cost of electromagnetic wave regulation.

Description

Technical Field

[0001] The invention belongs to the field of radio frequency control of wireless communications and relates to a mechanically dynamically adjustable electromagnetic wave reflecting surface unit and an array type reflecting surface. Background Art

[0002] In the field of 6G wireless communications, the obstruction of wireless signals has always been a major bottleneck. In order to solve this problem, the directional reflection of electromagnetic waves can be achieved by designing a reflective surface, so that the wireless signal can bypass obstacles. The existing intelligent reflective surface adjusts the different states of the reflective unit to reflect electromagnetic waves in a specific direction. However, this solution has high cost, slow adjustment speed, large fluctuations in communication rate, and is difficult to support fast-moving user-side communications. Therefore, the present invention designs a mechanically dynamically adjustable electromagnetic wave reflective surface, which does not require the use of a circuit structure, greatly reduces costs, and can dynamically regulate electromagnetic waves to cover electromagnetic waves in specific directions and trajectories. Summary of the invention

[0003] In view of the serious obstruction of 6G wireless signals and the shortcomings of existing intelligent reflective surface solutions, such as high cost, slow adjustment speed and large fluctuations in communication rate, the present invention designs a mechanically dynamically adjustable electromagnetic wave reflective surface unit and an array reflective surface.

[0004] The objective of the present invention is achieved through the following technical solutions:

[0005] According to a first aspect of the present specification, a mechanically dynamically adjustable electromagnetic wave reflecting surface unit is provided, comprising an outer frame, an inner frame, a reflecting sheet, an outer steering gear, an inner steering gear, an outer gear set and an inner gear set; the outer gear set comprises a first outer gear and a second outer gear; the inner gear set comprises a first inner gear and a second inner gear; the outer frame is a rectangular ring frame structure, one side of which is fixed with the first outer gear; the inner frame is a rectangular ring frame structure, the top and bottom sides of which respectively lead out brackets for fixing the outer steering gear, and the top side of which is internally fixed with the first inner gear; the outer sides of the two side sides of the inner frame are connected to the inner sides of the two side sides of the outer frame through bearings; the outer sides of the top and bottom sides of the reflecting sheet are connected to the inner sides of the top and bottom sides of the inner frame through bearings, and the back side of the reflecting sheet leads out a bracket for fixing the inner steering gear; the outer steering gear is connected to the second outer gear, and the second outer gear is meshed with the first outer gear; the inner steering gear is connected to the second internal gear, and the second internal gear is meshed with the first internal gear.

[0006] Furthermore, the position of the outer frame is fixed. When the outer servo is working, the second outer gear is driven to rotate. Since the position of the first outer gear is fixed and the outer servo is fixed on the bracket of the inner frame, the inner frame is driven to pitch. The pitch rotation of the inner frame will drive the reflector to pitch synchronously. When the inner servo is working, the second inner gear is driven to rotate. Since the position of the first inner gear is fixed and the inner servo is fixed on the back bracket of the reflector, the reflector is driven to yaw.

[0007] Furthermore, the movements of the outer steering gear and the inner steering gear do not interfere with each other, so that the reflector has the ability to rotate with two degrees of freedom, namely, rotating around two mutually perpendicular axes, horizontally and vertically.

[0008] Furthermore, the bearing connection between the inner frame and the outer frame, and the bearing connection between the inner frame and the reflective sheet, are both achieved by interference fit; the processing method of the outer frame, inner frame, reflective sheet, and gear is achieved by 3D printing or duplication, and the material is weakly conductive, including polylactic acid, acrylic acid, and resin; a strong conductivity coating with electromagnetic wave reflection capability is added to the surface of the reflective sheet, and the implementation method includes aluminum foil and electroplating.

[0009] According to the second aspect of the present specification, a mechanically dynamically adjustable electromagnetic wave reflecting surface is provided, which is composed of a number of reflecting surface units described in the first aspect tightly arranged in an array form around an outer frame; the size, structure and control method of each reflecting surface unit are consistent.

[0010] Furthermore, the electromagnetic wave reflecting surface projects the electromagnetic wave onto a special track in the electromagnetic wave projection area, specifically:

[0011] The mechanically dynamically adjustable electromagnetic wave reflecting surface comprises M r ×N r reflection surface units, the electromagnetic wave projection area contains M p ×N p grids, the special trajectory contains N t grids, where N t <M r ×N r ; The electromagnetic wave projection area is the smallest rectangular area containing the special trajectory;

[0012] Let each projection trajectory grid correspond to n reflection surface units, in Indicates rounding down. At this time, N t ×n reflection surface units and projection trajectory grid mapping are completed;

[0013] For the remaining M r ×N r -N t Each of the reflection surface units in the ×n reflection surface units, and its corresponding projection trajectory grid should be such that Minimize, where It means to find the variance of different projection trajectory grids i, is the reflection surface unit i j The received power to the projection track grid i, the reflection surface unit i jIndicates that the reflection surface unit is the jth reflection surface unit mapped to the projection track grid i; one by one for the remaining M r ×N r -N t Each of the n reflecting surface units is selected so that The minimized projection trajectory grid completes the mapping of all reflection surface units, i.e., all reflection sheets, to the electromagnetic wave projection trajectory grid.

[0014] Furthermore, the access point acts as a transmitter, and the millimeter wave emitted by the transmitter is reflected by the reflecting surface and reaches the projection track, and then is received by the receiver on the projection track; for any point Q on the projection track i , when the reflective surface is used to eliminate the occlusion of obstacles, the trajectory point Q i The received power P r (Q i ) is expressed as:

[0015]

[0016] Among them, P t is the power of the millimeter wave transmitted by the access point, G t is the millimeter wave antenna gain of the access point, G r is the receiver’s millimeter-wave antenna gain, d AR,i is the distance from the access point to the center of the reflecting surface, d RP,i From the center of the reflection surface to the trajectory point Q i The distance, σ i is the radar scattering cross-sectional area corresponding to the reflecting surface; the access point and the trajectory point Q i The distance between them is denoted as d AP,i , connect the access point-reflection surface center and the access point-trajectory point Q i The angle between them is denoted as α RP,i , access point - trajectory point Q i and the center of the reflection surface - trajectory point Q i The angle between them is denoted as α AR ,i, then according to the geometric relationship, the trajectory point Q i The received power P r (Q i ) is expressed as:

[0017]

[0018] Among them, σ max Represents the maximum value of the radar cross-sectional area corresponding to the reflecting surface, η i It represents the millimeter wave reflection gain introduced by the reflecting surface, and the formula is as follows:

[0019]

[0020] For the trajectory point Q i In order to obtain the optimal reflector deployment position and orientation on the entire trajectory, the optimization goal is set to make the trajectory point Q i The received power P r (Q i ) is the largest; the optimization problem is written as follows:

[0021]

[0022] subject to:α AR,i ∈[α AR,min ,α AR,max ],α RP,i ∈[α RP,min ,α RP,max ]

[0023] Among them, [α AR,min ,α AR,max ] represents the α corresponding to the reflecting surface that enables the millimeter wave to bypass obstacles AR,i Range, [α RP,min ,α RP,max ] represents the α corresponding to the reflecting surface that enables the millimeter wave to bypass obstacles RP,i Scope; solve the optimization problem, and the optimal solution obtained includes the position and orientation of the reflecting surface;

[0024] For different points Q i The optimal deployment position and orientation of the reflecting surface are obtained respectively, and the centroid of different reflecting surface positions is taken as the actual deployment position of the reflecting surface. Since the position and orientation of the reflecting surface are coupled with each other, the actual deployment orientation of the reflecting surface is obtained.

[0025] Furthermore, the size of the reflecting surface unit depends on the Rayleigh roughness criterion; in order to enable each reflecting surface unit to have precise control capability, it is necessary to ensure that the roughness height difference h of the entire reflecting surface satisfies h>λ / 8, where λ is the wavelength of the electromagnetic wave.

[0026] Furthermore, according to the multi-beam synthesis algorithm, the reflection direction and projection trajectory of the electromagnetic wave are changed by adjusting the angles of multiple reflection surface units, specifically:

[0027] For any reflective surface unit, the four vertex angles of the reflective surface unit are connected clockwise in sequence and recorded as ABDC, and the normal vector of the plane corresponding to the reflective surface unit is adjusted to vector N, and the vector N is obtained by the geometric relationship between the positions of the access point, the reflective surface unit, and the projection point;

[0028] For triangle ABC, take A as the coordinate origin of the reflective surface unit, fix the position of point A, fix the horizontal positions of points B and C, adjust the heights of points B and C so that the normal vector of triangle ABC is adjusted to vector N, and solve the following equation to obtain the heights of points B and C:

[0029]

[0030] For the triangle BDC, the positions of points B and C are known, and the horizontal position of point D is fixed. By adjusting the heights of points B and C, the normal vector of triangle BDC is adjusted to vector N. Solve the following equation to find the height of point D:

[0031]

[0032] The normal vectors of all reflection surface units of the electromagnetic wave reflection surface are obtained, thereby completing the angle control of the entire reflection surface.

[0033] Furthermore, the electromagnetic wave reflecting surface also includes a wireless control system, which includes a wireless communication module, a host computer, a microcontroller and a reflecting surface control bus; the wireless communication module obtains the positioning information of the trajectory to be projected from the host computer according to the set sampling rate, and then transmits it to the microcontroller. The microcontroller converts the positioning information into a control signal for each reflecting surface unit based on the geometric relationship and the multi-beam synthesis algorithm adopted, and then transmits the control signal to the external servo and internal servo of each reflecting surface unit via the reflecting surface control bus.

[0034] The beneficial effects of the present invention are as follows: the mechanically dynamically adjustable electromagnetic wave reflecting surface unit provided by the present invention comprises an outer frame, an inner frame, a reflecting sheet, an outer servo, an inner servo, an outer gear set and an inner gear set; the outer servo is connected to the outer gear to drive the inner frame to rotate, and the rotation of the inner frame will drive the reflecting sheet to rotate; the inner servo is connected to the inner gear to drive the reflecting sheet to rotate; the movements of the outer servo and the inner servo do not interfere with each other, so that the reflecting sheet has two degrees of freedom of rotation, namely: rotating around two mutually perpendicular axes, horizontally and vertically. A plurality of reflecting surface units are closely arranged around the outer frame to form an array reflecting surface. By adjusting the angles of multiple reflecting surface units, the reflection direction, projection trajectory, etc. of the electromagnetic wave are changed, and the effect of the traditional circuit structure antenna array is achieved with a non-circuit structure, reducing the cost of electromagnetic wave control. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0036] Figure 1 is a schematic structural diagram of an exemplary embodiment of the present invention at a first viewing angle;

[0037] Figure 2 is a schematic structural diagram of an exemplary embodiment of the present invention at a second viewing angle;

[0038] Figure 3 is a schematic structural diagram of an exemplary embodiment of the present invention at a third viewing angle;

[0039] Figure 4 is a schematic diagram of the structure of an external gear used in an external steering gear in an exemplary embodiment of the present invention;

[0040] Figure 5 is a schematic diagram of the structure of an internal gear used in an internal steering gear in an exemplary embodiment of the present invention;

[0041] Figure 6 is a schematic structural diagram of an outer frame in an exemplary embodiment of the present invention;

[0042] Figure 7 is a schematic structural diagram of an inner frame in an exemplary embodiment of the present invention;

[0043] Figure 8 is a schematic structural diagram of a reflective sheet in an exemplary embodiment of the present invention;

[0044] Fig. 9 is a schematic structural diagram of a reflective surface unit array in an exemplary embodiment of the present invention;

[0045] Fig.10 is a reflector power and deployment position orientation model in an exemplary embodiment of the present invention;

[0046] Fig.11 is a schematic diagram of millimeter wave reflection gain in an exemplary embodiment of the present invention;

[0047] Fig.12 is a schematic diagram of angle adjustment of a reflective surface unit in an exemplary embodiment of the present invention;

[0048] Fig.13 is a schematic structural diagram of a wireless control system in an exemplary embodiment of the present invention;

[0049] In the figure: 1-outer frame; 2-inner frame; 3-reflector; 4-outer servo; 5-inner servo; 6-outer gear; 7-inner gear; 8-reflector control bus; 9-microcontroller; 10-wireless communication module; 11-host computer. DETAILED DESCRIPTION

[0050] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0051] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0052] like Figure 1 , Figure 2 , Figure 3 As shown, the embodiment of the present invention provides a mechanically dynamically adjustable electromagnetic wave reflecting surface unit, including: an outer frame 1, an inner frame 2, a reflector 3, an outer steering gear 4, an inner steering gear 5, an outer gear set 6, an inner gear set 7, bearings and other components. The gear structure of the outer gear set 6 is shown in FIG. Figure 4 As shown, the structure of the internal gear 7 is shown in FIG. Figure 5 As shown, the structure of the outer frame 1 refers to Figure 6 As shown, the structure of the inner frame 2 is referenced Figure 7 As shown, the structure of the reflector 3 is shown in FIG. Figure 8 shown.

[0053] The outer gear set 6 includes a first outer gear and a second outer gear. The inner gear set 7 includes a first inner gear and a second inner gear. The outer frame 1 is a rectangular ring frame structure, and the first outer gear is fixed on one side thereof. The inner frame 2 is a rectangular ring frame structure, and the top and bottom sides thereof respectively lead out brackets for fixing the outer servo 4, and the first inner gear is fixed on the inside of the top side thereof. The outer sides of the two side sides of the inner frame 2 are connected to the inner sides of the two side sides of the outer frame 1 through bearings. The outer sides of the top and bottom sides of the reflector 3 are respectively connected to the inner sides of the top and bottom sides of the inner frame 2 through bearings, and the back side of the reflector 3 leads out brackets for fixing the inner servo 5. The outer servo 4 is connected to the second outer gear, and the second outer gear is meshed with the first outer gear. The inner servo 5 is connected to the second inner gear, and the second inner gear is meshed with the first inner gear.

[0054] The outer frame 1 is fixed in position. When the outer servo 4 is working, it drives the second outer gear to rotate. Since the first outer gear is fixed in position and the outer servo 4 is fixed on the bracket of the inner frame 2, the inner frame 2 is driven to pitch and rotate. The pitch rotation of the inner frame 2 will drive the reflector 3 to pitch synchronously. When the inner servo 5 is working, it drives the second inner gear to rotate. Since the first inner gear is fixed in position and the inner servo 5 is fixed on the back bracket of the reflector 3, the reflector 3 is driven to yaw and rotate.

[0055] Furthermore, the connection between the outer servo 4 and the second outer gear can be a variety of connection methods such as gluing; the connection between the inner servo 5 and the second inner gear can be a variety of connection methods such as gluing; the movements of the outer servo 4 and the inner servo 5 do not interfere with each other, so that the reflector 3 has the ability to rotate with two degrees of freedom, namely: rotating around two mutually perpendicular axes, horizontal and vertical.

[0056] Furthermore, the bearing connection between the inner frame 2 and the outer frame 1 , and the bearing connection between the inner frame 2 and the reflective sheet 3 , are both achieved by interference fit.

[0057] Furthermore, the processing methods of the outer frame 1, the inner frame 2, the reflective sheet 3, the gears and other components can be achieved by various methods such as 3D printing and molding, and their materials are weakly conductive, including polylactic acid, acrylic acid, resin, etc.; in order to make the reflective sheet 3 have the ability to reflect electromagnetic waves, it is necessary to add a coating with strong conductivity on the surface, and the implementation methods include aluminum foil, electroplating, etc.

[0058] Furthermore, in order to reduce system cost and ensure the accuracy of electromagnetic wave control, both the inner servo 5 and the outer servo 4 are controlled by PWM signals. In this embodiment, the inner servo and the outer servo are SG90 9g servos, which have a rotation range of 180°, a position level of 1024, and an angle resolution of 180° / 1024=0.1758°, meeting the precision control requirements of electromagnetic wave control.

[0059] Reference Fig. 9 As shown, multiple mechanically dynamically adjustable electromagnetic wave reflecting surface units can be closely arranged in an array form through an outer frame to form an overall reflecting surface. Multiple mechanically dynamically adjustable electromagnetic wave reflecting surface units can be closely arranged through an outer frame in a variety of connection ways such as gluing, bundling, and screw fixing; the size, structure, and control method of each mechanically dynamically adjustable electromagnetic wave reflecting surface unit are consistent.

[0060] Furthermore, the mechanically dynamically adjustable electromagnetic wave reflecting surface can project the electromagnetic wave onto a special track in the electromagnetic wave projection area. Specifically, the mechanically dynamically adjustable electromagnetic wave reflecting surface includes M r ×N r reflection surface units, the electromagnetic wave projection area contains M p ×N p grids, special trajectories contain N t grids, where N t <M r ×N r The electromagnetic wave projection area is the smallest rectangular area containing the special trajectory, which is evenly discretized into M p ×N p Grids, M p N p ≤Mr N r .

[0061] Furthermore, considering the disadvantage of millimeter wave attenuation, the electromagnetic wave projection method relies on the power averaging algorithm to make the electromagnetic wave intensity on the target electromagnetic wave projection trajectory more uniform and reduce the beam scanning delay caused by the change of signal strength during wireless communication. Specifically, each projection trajectory grid corresponds to n reflection surface units, where n is defined as follows:

[0062]

[0063] in, Indicates rounding down; at this time, N t ×n reflection surface units are mapped to the projection trajectory grid.

[0064] According to Friss's free space propagation theorem of electromagnetic waves, we have:

[0065]

[0066] in, is the reflection surface unit i j The transmission power to the projection trajectory grid i, is the reflection surface unit i j The received power to the projection trajectory grid i, is the reflection surface unit i j The transmit antenna gain to the projection trajectory grid i, is the reflection surface unit i j The receiving antenna gain to the projection track grid i, the reflector element i j Indicates that the reflection surface unit is the jth reflection surface unit mapped to the projection track grid i, λ is the wavelength of the electromagnetic wave, is the reflection surface unit i j Distance to projection track grid i. Distance from reflection surface unit i j Different electromagnetic waves reaching the projection trajectory grid i, due to the propagation path Different, from the reflection surface unit i j The received power to the projection trajectory grid i Although n reflection surface units are equally allocated to each projection track grid, the received power of each projection track grid is different. In order to make the total electromagnetic wave power at the projection track grid i the same, the following conditions are met:

[0067]

[0068] in, In order to achieve the above conditions, a reflector unit power allocation algorithm is designed. Specifically, for the remaining M r ×N r -N t Each of the reflection surface units in the ×n reflection surface units, and its corresponding projection trajectory grid should be such that Minimize, and based on this, one by one for the remaining M r ×N r -N t Each of the n reflecting surface units is selected so that Minimized projection track grid. Thus, the mapping of all reflection surface units, i.e. all reflection sheets, to the electromagnetic wave projection track grid is completed.

[0069] Furthermore, the access point acts as a transmitter, and the millimeter wave emitted by the transmitter reaches the projection track after being reflected by the reflection surface, and is then received by the receiver on the projection track. Fig.10 is the reflector power and deployment position orientation model diagram. For any point Q on the projection trajectory i For example, when the reflective surface is used to eliminate the occlusion of obstacles, point Q i The received power P r (Q i ) can be expressed as:

[0070]

[0071] Among them, P t is the power of the millimeter wave transmitted by the access point, G t is the millimeter wave antenna gain of the access point, G r is the receiver’s millimeter-wave antenna gain, d AR,i is the distance from the access point to the center of the reflecting surface, d RP,i From the center of the reflection surface to the trajectory point Q i The distance, σ i is the radar cross-sectional area RCS corresponding to the reflecting surface. Further, the access point and the trajectory point Q i The distance between them is denoted as d AP,i , connect the access point-reflection surface center and the access point-trajectory point Q i The angle between them is denoted as α RP,i , access point - trajectory point Q i and the center of the reflection surface - trajectory point Q i The angle between them is denoted as α AR,i , then according to the geometric relationship, the trajectory point Q i The received power P r (Q i ) can be expressed as:

[0072]

[0073] in, represents the millimeter-wave reflection gain introduced by the reflecting surface. Specifically, the numerator represents the grazing loss introduced by the reflecting surface in different directions, and the denominator represents the path loss introduced by the reflecting surface in different positions; σ max Indicates the maximum value of the radar cross-sectional area RCS corresponding to the reflecting surface. For point Q on the projection trajectory i In order to obtain the optimal reflector deployment position and orientation on the entire trajectory, the optimization goal can be set to make the trajectory point Q i The received power P r (Q i ) is the largest. Therefore, the optimization problem can be written as follows:

[0074]

[0075] subject to:α AR,i ∈[α AR,min ,α AR,max ],α RP,i ∈[α RP,min ,α RP,max ]

[0076] Among them, [α AR,min ,α AR,max ] represents the α corresponding to the reflecting surface that enables the millimeter wave to bypass obstacles AR,i Range, [α RP,min ,α RP,max ] represents the α corresponding to the reflecting surface that enables the millimeter wave to bypass obstacles RP,i The above optimization problem can be solved by optimization algorithms such as stochastic gradient descent and greedy algorithm, and the optimal solution obtained includes the position and orientation of the reflecting surface.

[0077] When AP,i =5m, the millimeter wave reflection gain introduced by the reflecting surface is related to α AR,i , α RP,i The relationship is as Fig.11 As shown, intuitively, the optimal α that maximizes the millimeter wave reflection gain can be searched AR,i With α RP,i . Specifically, when α AR,i Large value, α RP,i The value is small (corresponding to the reflector being close to the receiver), or when α AR,i Small value, α RP,i When the value is large (corresponding to the reflector being close to the access point), the millimeter wave reflection gain is greater. In order to obtain the optimal reflector deployment position and orientation for a special trajectory, the entire projection trajectory needs to be discretized first, that is, represented as different points Qi ; Then, for different points Q i The optimal deployment position and orientation of the reflecting surface are obtained respectively, and finally the centroid of different reflecting surface positions is taken as the actual deployment position of the reflecting surface. Since the position and orientation of the reflecting surface are coupled with each other, the actual deployment orientation of the reflecting surface can be directly obtained.

[0078] Furthermore, the size of the mechanically dynamically adjustable electromagnetic wave reflecting surface unit depends on the Rayleigh roughness criterion. In order to make each mechanically dynamically adjustable electromagnetic wave reflecting surface unit have the ability of precise control, it is necessary to ensure that the roughness height difference h of the entire reflecting surface satisfies h>λ / (8cosθ), where λ is the wavelength of the electromagnetic wave and θ is the incident angle of the electromagnetic wave. In order to obtain the lower limit of the roughness height difference h of the entire reflecting surface, it is necessary to ensure that h>λ / 8. In order to describe the roughness height difference h of the entire reflecting surface, it is defined from the horizontal and vertical aspects respectively. The roughness height differences in the horizontal and vertical directions are respectively

[0079]

[0080]

[0081] Among them, h i ' ,j Represents the height of the lower right corner vertex of the mechanically dynamically adjustable electromagnetic wave reflecting surface unit in the i-th row and j-th column.

[0082] Furthermore, based on the multi-beam synthesis algorithm, by adjusting the angles of multiple reflection surface units, the reflection direction and projection trajectory of the electromagnetic wave can be changed, and the effect of the traditional circuit structure antenna array can be achieved with a non-circuit structure. Fig.12 This is a schematic diagram of the angle control of the reflection surface unit in the embodiment of the present invention. The angle control of each mechanically dynamically adjustable electromagnetic wave reflection surface unit is obtained through the geometric relationship between the incident electromagnetic wave, each mechanically dynamically adjustable electromagnetic wave reflection surface unit, and the outgoing electromagnetic wave. For any mechanically dynamically adjustable electromagnetic wave reflection surface unit, the four vertex angles of the reflection surface unit are connected clockwise in sequence and recorded as ABDC. The normal vector of the plane corresponding to the reflection surface unit is adjusted to vector N, and vector N can be obtained from the geometric relationship through the positions of the access point, the reflection surface unit, and the projection point. For the triangle ABC, A is used as the coordinate origin of the reflection surface unit, the position of point A is fixed, and the horizontal positions of points B and C are fixed. The normal vector of triangle ABC is adjusted to vector N by adjusting the heights of points B and C. Solve the following equation to obtain the heights of points B and C:

[0083]

[0084] Similarly, for the triangle BDC, the positions of points B and C are known, the horizontal position of point D is fixed, and the normal vector of triangle BDC is adjusted to vector N by adjusting the heights of points B and C. Solve the following equation to find the height of point D:

[0085]

[0086] By analogy, the normal vectors of all the reflecting surface units of the reflecting surface can be obtained, thereby completing the angle control of the entire reflecting surface.

[0087] Further, Fig.13 : is a schematic diagram of the structure of the wireless control system in the embodiment of the present invention. In order to realize the control of the reflective surface by hardware circuit, the wireless communication module 10 is used to obtain the positioning information of the trajectory to be projected from the host computer 11 at a certain sampling rate, and then transmit it to the microcontroller 9, and the microcontroller 9 converts the positioning information into a control signal of each mechanically adjustable electromagnetic wave reflective surface unit according to the geometric relationship and the multi-beam synthesis algorithm adopted, and then the microcontroller 9 transmits the generated control signal to the outer steering gear 4 and the inner steering gear 5 of each mechanically adjustable electromagnetic wave reflective surface unit through the reflective surface control bus 8.

[0088] Furthermore, the wireless communication module 10 used should preferably use low-frequency electromagnetic waves with good stability and strong penetration, including but not limited to wireless communication methods such as WiFi, Bluetooth, and 4G; the positioning information of the trajectory to be projected obtained from the host computer 11 can use various positioning methods, including but not limited to GPS positioning, LoRa positioning, WiFi CSI assisted positioning, side channel information positioning, etc.

[0089] The above description is merely a preferred embodiment of one or more embodiments of the present specification and is not intended to limit one or more embodiments of the present specification. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of the present specification shall be included in the scope of protection of one or more embodiments of the present specification.

Claims

1. A mechanically dynamically adjustable electromagnetic wave reflecting surface unit, characterized in that: The invention comprises an outer frame, an inner frame, a reflective sheet, an outer steering gear, an inner steering gear, an outer gear set and an inner gear set; the outer gear set comprises a first outer gear and a second outer gear; the inner gear set comprises a first inner gear and a second inner gear; the outer frame is a rectangular ring frame structure, one side of which is fixed with the first outer gear; the inner frame is a rectangular ring frame structure, the top and bottom sides of which respectively lead out brackets for fixing the outer steering gear, and the first inner gear is fixed inside the top side; the two side sides of the inner frame are connected to the two side sides of the outer frame through bearings; the top and bottom sides of the reflective sheet are connected to the top and bottom sides of the inner frame through bearings, and the back of the reflective sheet is fixed to the inner frame. The surface leads to a bracket for fixing the inner steering gear; the outer steering gear is connected to the second outer gear, and the second outer gear is meshed with the first outer gear; the inner steering gear is connected to the second inner gear, and the second inner gear is meshed with the first inner gear; the outer frame is fixed in position, and when the outer steering gear is working, the second outer gear is driven to rotate, and because the first outer gear is fixed in position and the outer steering gear is fixed on the bracket of the inner frame, the inner frame is driven to pitch, and the pitch rotation of the inner frame will drive the synchronous pitch rotation of the reflector; when the inner steering gear is working, the second inner gear is driven to rotate, and because the first inner gear is fixed in position and the inner steering gear is fixed on the back bracket of the reflector, the reflector is driven to yaw.

2. The mechanically dynamically adjustable electromagnetic wave reflecting surface unit according to claim 1, characterized in that: The movements of the outer steering gear and the inner steering gear do not interfere with each other, so that the reflector has the ability to rotate with two degrees of freedom, that is, to rotate around two mutually perpendicular axes, horizontally and vertically.

3. The mechanically dynamically adjustable electromagnetic wave reflecting surface unit according to claim 1, characterized in that: The bearing connection between the inner frame and the outer frame, as well as the bearing connection between the inner frame and the reflector, are all achieved by interference fit; the processing method of the outer frame, inner frame, reflector, and gear is achieved by 3D printing or duplication, and the material is weakly conductive, including polylactic acid, acrylic acid, and resin; a strong conductivity coating with electromagnetic wave reflection ability is added to the surface of the reflector, and the implementation method includes any one of aluminum foil and electroplating.

4. A mechanically dynamically adjustable electromagnetic wave reflecting surface, characterized in that: The reflective surface units described in any one of claims 1 to 3 are closely arranged in an array form through an outer frame; the size, structure and control method of each reflective surface unit are consistent.

5. The mechanically dynamically adjustable electromagnetic wave reflecting surface according to claim 4, characterized in that: The electromagnetic wave reflecting surface projects the electromagnetic wave onto a special track in the electromagnetic wave projection area, specifically: The mechanically dynamically adjustable electromagnetic wave reflecting surface comprises M r ×N r reflection surface units, the electromagnetic wave projection area contains M p ×N p grids, the special trajectory contains N t grids, where N t <M r ×N r ; The electromagnetic wave projection area is the smallest rectangular area containing the special trajectory; Let each projection trajectory grid correspond to n reflection surface units, in Indicates rounding down. At this time, N t ×n reflection surface units and projection trajectory grid mapping are completed; For the remaining M r ×N r -N t Each of the reflection surface units in the ×n reflection surface units, and its corresponding projection trajectory grid should be such that Minimize, where It means to find the variance of different projection trajectory grids i, is the reflection surface unit i j The received power to the projection track grid i, the reflection surface unit i j Indicates that the reflection surface unit is the jth reflection surface unit mapped to the projection track grid i; one by one for the remaining M r ×N r -N t Each of the n reflecting surface units is selected so that The minimized projection trajectory grid completes the mapping of all reflection surface units, i.e., all reflection sheets, to the electromagnetic wave projection trajectory grid.

6. The mechanically dynamically adjustable electromagnetic wave reflecting surface according to claim 5, characterized in that: The access point acts as a transmitter. The millimeter wave emitted by the transmitter is reflected by the reflecting surface and reaches the projection track, and then is received by the receiver on the projection track. For any point Q on the projection track i , when the reflective surface is used to eliminate the occlusion of obstacles, the trajectory point Q i The received power P r (Q i ) is expressed as: Among them, λ is the wavelength of the electromagnetic wave, P t is the power of the millimeter wave transmitted by the access point, G t is the millimeter wave antenna gain of the access point, G r is the receiver’s millimeter-wave antenna gain, d AR,i is the distance from the access point to the center of the reflecting surface, d RP,i From the center of the reflection surface to the trajectory point Q i The distance, σ i is the radar scattering cross-sectional area corresponding to the reflecting surface; the access point and the trajectory point Q i The distance between them is denoted as d AP,i , connect the access point-reflection surface center and the access point-trajectory point Q i The angle between them is denoted as α RP,i , access point - trajectory point Q i and the center of the reflection surface - trajectory point Q i The angle between them is denoted as α AR,i , then according to the geometric relationship, the trajectory point Q i The received power P r (Q i ) is expressed as: Among them, σ max Represents the maximum value of the radar cross-sectional area corresponding to the reflecting surface, η i It represents the millimeter wave reflection gain introduced by the reflecting surface, and the formula is as follows: For the trajectory point Q i In order to obtain the optimal reflector deployment position and orientation on the entire trajectory, the optimization goal is set to make the trajectory point Q i The received power P r (Q i ) is the largest; the optimization problem is written as follows: subject to:a AR,i ∈[a AR,min ,a AR,max ],a RP,i ∈[a RP,min ,a RP,max ] Among them, [α AR,min ,α AR,max ] represents the α corresponding to the reflecting surface that enables the millimeter wave to bypass obstacles AR,i Range, [α RP,min ,α RP,max ] represents the α corresponding to the reflecting surface that enables the millimeter wave to bypass obstacles RP,i Scope; solve the optimization problem, and the optimal solution obtained includes the position and orientation of the reflecting surface; For different points Q i The optimal deployment position and orientation of the reflecting surface are obtained respectively, and the centroid of different reflecting surface positions is taken as the actual deployment position of the reflecting surface. Since the position and orientation of the reflecting surface are coupled with each other, the actual deployment orientation of the reflecting surface is obtained.

7. The mechanically dynamically adjustable electromagnetic wave reflecting surface according to claim 4, characterized in that: The size of the reflection surface unit depends on the Rayleigh roughness criterion; in order to enable each reflection surface unit to have precise control capability, it is necessary to ensure that the roughness height difference h of the entire reflection surface satisfies h>λ / 8, where λ is the wavelength of the electromagnetic wave.

8. The mechanically dynamically adjustable electromagnetic wave reflecting surface according to claim 4, characterized in that: According to the multi-beam synthesis algorithm, the reflection direction and projection trajectory of the electromagnetic wave are changed by adjusting the angles of multiple reflective surface units. Specifically: For any reflective surface unit, the four vertex angles of the reflective surface unit are connected clockwise in sequence and recorded as ABDC, and the normal vector of the plane corresponding to the reflective surface unit is adjusted to vector N, wherein the vector N is obtained by the geometric relationship between the positions of the access point, the reflective surface unit, and the projection point; For triangle ABC, take A as the coordinate origin of the reflective surface unit, fix the position of point A, fix the horizontal positions of points B and C, adjust the heights of points B and C so that the normal vector of triangle ABC is adjusted to vector N, and solve the following equation to obtain the heights of points B and C: For the triangle BDC, the positions of points B and C are known, and the horizontal position of point D is fixed. By adjusting the heights of points B and C, the normal vector of triangle BDC is adjusted to vector N. Solve the following equation to find the height of point D: The normal vectors of all reflection surface units of the electromagnetic wave reflection surface are obtained, thereby completing the angle control of the entire reflection surface.

9. The mechanically dynamically adjustable electromagnetic wave reflecting surface according to claim 8, characterized in that: It also includes a wireless control system, which includes a wireless communication module, a host computer, a microcontroller and a reflective surface control bus; the wireless communication module obtains the positioning information of the trajectory to be projected from the host computer according to the set sampling rate, and then transmits it to the microcontroller; the microcontroller converts the positioning information into a control signal for each reflective surface unit based on the geometric relationship and the multi-beam synthesis algorithm adopted, and then transmits the control signal to the external servo and internal servo of each reflective surface unit through the reflective surface control bus.

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