Ground station antenna regulation and control device, communication system and method

Abstract

The invention discloses a ground station antenna regulation and control device, a communication system and a method. The device comprises a digital image transmission antenna and a regulation and control holder, wherein the digital image transmission antenna comprises a feed source antenna and a reflective array; the feed source antenna and the reflective array are both connected with the regulation and control holder; the feed source antenna is aligned with the array plane center of the reflective array; performing phase compensation on the electromagnetic waves emitted to the reflective array surface by the feed source antenna through the reflective array so as to convert the spherical electromagnetic waves emitted by the feed source antenna into planar electromagnetic waves; and in response to a received angle adjustment instruction, adjusting a yaw angle and a pitch angle of the digital image transmission antenna according to the to-be-compensated rotation angle carried by the angle adjustment instruction. According to the invention, the antenna gain is effectively increased, and the path loss is compensated.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and in particular to a ground station antenna control device, a communication system and a method. Background Art

[0002] The flight time of existing power inspection drones is about 0.5 to 1 hour. Calculated at a flight speed of 10m / s, the maximum flight range is about 36km. Considering the power for forced landing, inspection operation time and return time, the maximum operating radius is about 10km. It is known that the propagation loss of electromagnetic waves in free space is related to the propagation distance and frequency. There is an existing power inspection long-flight drone with a flight time of up to 2 hours. Calculated at a flight speed of 10m / s, the maximum operating radius is about 28km, and the propagation loss increases by 8.94dB. Since the sensitivity of the receiving end is proportional to the power of the transmitting end, the antenna gain of the transmitting end and the antenna gain of the receiving end, and inversely proportional to the loss of the transmitting end, the propagation loss and the loss of the receiving end, it can be seen that the path loss can be compensated by increasing the antenna gain of the transmitting end and the receiving end.

[0003] In the prior art, the digital image transmission antennas commonly used in drones are mainly omnidirectional antennas with an antenna gain of approximately 3 to 5 dB, which cannot overcome long-distance path loss. Summary of the invention

[0004] The present invention provides a ground station antenna control device, a communication system and a method to solve the technical problem in the prior art that the long-distance path loss cannot be overcome due to the small antenna gain.

[0005] According to one aspect of the present invention, a ground station antenna control device is provided, comprising: a digital image transmission antenna and a control platform; wherein the digital image transmission antenna comprises a feed antenna and a reflector array; the feed antenna and the reflector array are both connected to the control platform; the feed antenna is aligned with the center of the reflector surface of the reflector array;

[0006] Performing phase compensation on the electromagnetic waves emitted by the feed antenna to the reflection array through the reflection array, so as to convert the spherical electromagnetic waves emitted by the feed antenna into planar electromagnetic waves;

[0007] The gimbal controller external to the control gimbal responds to the received angle adjustment instruction and adjusts the yaw angle and pitch angle of the digital image transmission antenna according to the rotation angle to be compensated carried in the angle adjustment instruction.

[0008] According to another aspect of the present invention, there is provided a communication system, comprising: a drone, a ground station, and a ground station antenna control device as described in any one of the above embodiments;

[0009] Wherein, the ground station antenna control device establishes a wired connection with the ground station, and the ground station establishes a wireless connection with the drone through the ground station antenna control device;

[0010] In response to the movement instruction of the UAV, the ground station determines the rotation angle to be compensated of the digital image transmission antenna based on the relative distance and relative height difference between the UAV and the ground station, and sends the rotation angle to be compensated to the antenna control device of the ground station, so that the control gimbal in the antenna control device of the ground station adjusts the yaw angle and pitch angle of the digital image transmission antenna according to the rotation angle to be compensated.

[0011] According to another aspect of the present invention, a communication method is provided, which is applied to the communication system as described in any one of the above embodiments; the method comprises:

[0012] The ground station determines the rotation angle to be compensated of the digital image transmission antenna in the antenna control device of the ground station based on the relative distance and relative height difference between the UAV and the ground station; the gimbal controller in the ground station sends the rotation angle to be compensated to the antenna control device of the ground station, so that the control gimbal in the antenna control device of the ground station adjusts the yaw angle and pitch angle of the digital image transmission antenna according to the rotation angle to be compensated.

[0013] The technical solution of the embodiment of the present invention is to correct the phase of the electromagnetic wave emitted by the feed antenna to the reflection array and then reflect it out. Since the feed antenna is a spherical wave before reflection, the reflection array can perform phase compensation on the spherical wave, thereby converting the spherical wave into a plane wave, thereby improving energy efficiency; and, the relative position between the feed antenna and the reflection array is fixed to ensure that the feed antenna and the reflection array are aligned with the center of the reflection array of the reflection array, thereby avoiding the situation where the radiation efficiency is reduced due to changes in the focal length and the incident angle between the feed antenna and the reflection array; and, when the gimbal controller connected to the control gimbal receives an angle adjustment instruction, the yaw angle and pitch angle of the digital image transmission antenna are adjusted according to the rotation angle to be compensated carried by the angle adjustment instruction, so as to ensure that the feed antenna and the reflection array follow the rotation of the drone, and ensure that the drone is always within the coverage range of the digital image transmission antenna in the ground station; and, the digital image transmission antenna adopts a reflection array antenna form, which increases the antenna gain, thereby compensating for the path loss, and overcoming the path loss problem of the long-flight drone during long-distance flight.

[0014] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. 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 creative work.

[0016] Figure 1 It is a structural block diagram of a ground station antenna control device provided by an embodiment of the present invention;

[0017] Figure 2 is a structural block diagram of another ground station antenna control device provided by an embodiment of the present invention;

[0018] Figure 3 It is a schematic diagram of the configuration of a rectangular waveguide horn antenna provided by an embodiment of the present invention;

[0019] Figure 4 is a schematic diagram of S parameter configuration of a feed antenna provided by an embodiment of the present invention;

[0020] Figure 5 is a schematic diagram of gain distribution of a feed antenna provided by an embodiment of the present invention;

[0021] Figure 6 is a structural schematic diagram of a reflective array unit provided by an embodiment of the present invention;

[0022] Figure 7 is a schematic diagram of phase shift distribution of each reflective array unit on a reflective array provided by an embodiment of the present invention;

[0023] Figure 8 It is a schematic diagram of the overall structure of a digital image transmission antenna provided by an embodiment of the present invention;

[0024] Fig. 9 is a structural block diagram of a communication system provided by an embodiment of the present invention;

[0025] Fig.10 is a flow chart of a communication method provided by an embodiment of the present invention;

[0026] Fig.11 It is a structural block diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0028] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0029] In one embodiment, Figure 1 This is a structural block diagram of a ground station antenna control device provided by an embodiment of the present invention. This embodiment is applicable to the case where the gain of the RF antenna of the ground station corresponding to the long-endurance UAV is adjusted. The ground station antenna control device can be implemented in the form of hardware and / or software, and the ground station antenna control device can be configured in the ground station. Figure 1 As shown, the ground station antenna control device includes: a digital image transmission antenna 10 and a control platform 20; wherein the digital image transmission antenna 10 includes a feed antenna 101 and a reflector array 102; the feed antenna 101 and the reflector array 102 are both connected to the control platform 20; the feed antenna 101 and the reflector array 102 are aligned with the center of the reflective array surface;

[0030] The electromagnetic waves emitted by the feed antenna 101 to the reflection array are phase compensated by the reflection array 102, so as to convert the spherical electromagnetic waves emitted by the feed antenna 101 into planar electromagnetic waves;

[0031] The gimbal controller external to the gimbal 20 responds to the received angle adjustment instruction and adjusts the yaw angle and pitch angle of the digital image transmission antenna 10 according to the rotation angle to be compensated carried in the angle adjustment instruction.

[0032] In one example, the ground station antenna control device is an independent device, which can be connected to the ground station by wire. In the embodiment, the reflector 102 uses the reflection of electromagnetic waves to perform phase compensation on the electromagnetic waves emitted by the feed antenna 101 to the reflection array and then reflects them out. Since the feed antenna 101 is a spherical wave before reflection, the reflection array can perform phase compensation on the spherical wave, thereby converting the spherical wave into a plane wave, thereby improving energy efficiency.

[0033] Among them, the angle adjustment instruction is used to characterize that the drone is about to leave the coverage of the digital image transmission antenna 10 in the ground station. In the actual communication process, the digital image transmission antenna 10 is a directional antenna, and the radiation direction of the electromagnetic wave is only in one direction, while the drone is moving in the sky. Correspondingly, the radiation direction of the digital image transmission antenna 10 needs to be adjusted. Specifically, after the gimbal controller connected to the control gimbal 20 receives the angle adjustment instruction, the yaw angle and pitch angle of the digital image transmission antenna 10 need to be adjusted to ensure that the drone is always within the coverage of the digital image transmission antenna 10 in the ground station. The digital image transmission antenna 10 can also be called the radio frequency antenna of the ground station. When the ground station is used as the transmitting end, electromagnetic waves can be transmitted through the digital image transmission antenna 10; when the ground station is used as the receiving end, electromagnetic waves can be received through the digital image transmission antenna 10. In an embodiment, the control gimbal 20 does not participate in the communication between the ground station and the drone, but the pitch angle and yaw angle of the digital image transmission antenna 10 can be adjusted by adjusting the rotation direction of the control gimbal 20. The pitch angle refers to the angle between the normal of the reflective array 102 and the horizontal plane; the yaw angle refers to the angle between the reflective array 102 and a pre-configured triangle mark position in the control platform. The adjustable upper limit of the pitch angle is 90 degrees; the position at the pre-configured triangle mark is 0 degrees, and when the control platform 20 rotates clockwise, the degree of the yaw angle increases continuously.

[0034] After each time the ground station is turned on, the ground station antenna control device in the ground station returns to the initial position, where the initial position can be a pitch angle of 90 degrees and a yaw angle of 0 degrees, to ensure that the ground station can receive the frequency request information of the drone in the air when it is not connected to the drone.

[0035] The technical solution of this embodiment is to correct the phase of the electromagnetic wave emitted by the feed antenna to the reflection array surface of the reflection array and then reflect it out. Since the feed antenna is a spherical wave before reflection, the reflection array surface can perform phase compensation on the spherical wave, thereby converting the spherical wave into a plane wave, thereby improving energy efficiency; and, fix the relative position between the feed antenna and the reflection array to ensure that the feed antenna and the center of the reflection array surface are aligned, thereby avoiding the situation where the radiation efficiency is reduced due to changes in the focal length and incident angle between the feed antenna and the reflection array; and, when receiving an angle adjustment instruction, adjust the yaw angle and pitch angle of the digital image transmission antenna according to the rotation angle to be compensated carried by the angle adjustment instruction, so as to ensure that the feed antenna and the reflection array rotate with the drone, and ensure that the drone is always within the coverage range of the digital image transmission antenna in the ground station; and, the digital image transmission antenna adopts a reflectarray antenna form, which increases the antenna gain and thereby compensates for the path loss.

[0036] In one embodiment, a gimbal controller receives a rotation angle to be compensated determined by a ground station, and controls and regulates the rotation direction of the gimbal based on the rotation angle to be compensated to adjust the yaw angle and pitch angle of the digital image transmission antenna; in the process of the gimbal controller controlling and regulating the rotation direction of the gimbal, the gimbal controller obtains the actual signal strength of the received digital image transmission signal emitted by the digital image transmission antenna, and controls and regulates the gimbal to stop rotating when the actual signal strength reaches a preset signal strength threshold.

[0037] Among them, the gimbal controller can be integrated into the ground station, and the gimbal can be controlled to communicate with the gimbal controller after establishing a connection with the ground station via a wired method. The preset signal strength threshold is used to characterize the threshold value for adjusting the angle of the digital image transmission antenna. For example, the preset signal strength threshold can be 25dBm; after the drone is turned on, it establishes a connection with the ground station at the take-off point, and obtains the location information of the drone and its own location information after the connection; then the ground station calculates the relative distance and relative height difference between the drone and the ground station based on the longitude and latitude, and calculates the rotation angle to be compensated through the existing formula, and sends the rotation angle to be compensated to the gimbal controller, so that the gimbal controller controls the rotation direction of the gimbal based on the rotation angle to be compensated to adjust the yaw angle and pitch angle of the digital image transmission antenna. While the gimbal controller is controlling the rotation direction of the gimbal, the gimbal controller also receives the actual signal strength of the digital image transmission signal emitted by the digital image transmission antenna, and when the actual signal strength reaches the preset signal strength threshold, controls the gimbal to stop rotating, so as to avoid the continuous turning of the digital image transmission antenna causing the mechanical structure of the antenna control to age. In addition, as a radio frequency antenna, the digital image transmission antenna itself has a certain radiation angle, and can maintain good signal strength even in the case of incomplete alignment. At the same time, it can be ensured that the direction in which the radio frequency antenna points must be the direction in which the drone is located, thereby ensuring that the antenna gain is increased while also extending the service life of the antenna control, thereby reducing hardware costs.

[0038] In one embodiment, Figure 2 1 is a structural block diagram of another ground station antenna control device provided by an embodiment of the present invention. This embodiment further refines the structure of the control platform based on the above embodiment. Figure 2 As shown, the control platform in this embodiment includes a turntable motor 201, a shaft motor 202, an antenna turntable 203, an antenna shaft 204, a feed antenna support frame 205, a reflector array support frame 206 and a shaft support frame 207; the rotation angle to be compensated includes the shaft angle to be compensated and the turntable angle to be compensated;

[0039] Among them, the antenna shaft 204 is arranged on the shaft support frame 207, the shaft support frame 207 is connected to the antenna turntable 203, and the turntable motor 201 is connected to the antenna turntable 203; the shaft motor 202 is located in the antenna shaft 204; the top of the feed antenna support frame 205 is used to fix the feed antenna 101, the bottom of the feed antenna support frame 205 is connected to the bottom of the reflector support frame 206, and the rear end of the reflector support frame 206 is connected to the antenna shaft 204;

[0040] The shaft motor 201 controls the rotation direction of the antenna shaft 204 according to the shaft angle to be compensated, so as to adjust the pitch angle of the digital image transmission antenna;

[0041] The turntable motor 202 controls the rotation direction of the antenna turntable 203 according to the turntable angle to be compensated, so as to adjust the yaw angle of the digital image transmission antenna.

[0042] Among them, the antenna turntable 203 is a concentric circle, and the outer circle is fixed, and the inner circle is movable. In an embodiment, the feed antenna support frame 205 and the antenna shaft 204 can be made of carbon fiber. The feed line of the feed antenna 101 is hidden in the feed antenna support frame 205, and the bottom of the feed antenna support frame 205 is connected to the bottom of the reflector array support frame 206, which can always ensure that the feed antenna 101 is aligned with the center of the reflector array 102. The antenna turntable 203 is a circular turntable, and the turntable motor 201 below it can drive the antenna turntable 203 to rotate, thereby realizing the rotation of the yaw angle of the digital image transmission antenna 10. At the same time, the rotation direction of the antenna shaft 204 can be controlled by the shaft motor 201, thereby realizing the rotation of the pitch angle of the digital image transmission antenna 10.

[0043] In one embodiment, the bottom of the feed antenna support frame 205 and the bottom of the reflector array support frame 206 are fixed by a triangular structure 208; the rear end of the reflector array support frame 206 and the antenna shaft 204 are fixed by a cross structure. The triangular structure 208 is a structure formed by three rods connected by nodes, that is, the tail end of the first rod 2081 is connected to the head end of the second rod 2082, the tail end of the second rod 2082 is connected to the head end of the third rod 2083, and the tail end of the third rod 2083 is connected to the head end of the first rod 2081. In order to ensure the stability of the feed antenna support frame, the feed antenna support frame is fixed by a triangular structure, so that the shaking caused by the rotation guide of the antenna can still be reduced. At the same time, a cross-shaped structure is formed between the reflector support frame 206 and a rod 209, that is, the reflector support frame 206 is fixed to the antenna shaft 204 by a cross-shaped structure, so that the shaft angle can be controlled by a shaft motor, thereby realizing the rotation of the pitch angle of the digital image transmission antenna.

[0044] In one embodiment, the feed antenna is any directional antenna selected from the group consisting of a microstrip antenna, a helical antenna, a Yagi antenna, and a rectangular waveguide horn antenna. In one example, the feed antenna may be a rectangular waveguide horn antenna. Figure 3 FIG. 1 is a schematic diagram of a configuration of a rectangular waveguide horn antenna provided by an embodiment of the present invention. Figure 3 As shown, the waveguide section length L g =51.69mm, width W g =40.58mm, height H g =20.29mm, antenna aperture width W a =119.4mm, height H a =87.43mm, length of the horn part L f =45.97mm.

[0045] In one embodiment, Figure 4 is a schematic diagram of S parameter configuration of a feed antenna provided by an embodiment of the present invention; Figure 5 FIG. 1 is a schematic diagram of a gain distribution of a feed antenna provided by an embodiment of the present invention. Figure 4 As shown in Figure 1, the resonance requirement is met within the 5.8 GHz frequency band (i.e., the center frequency band is 5.8 GHz). The gain of the feed antenna is Figure 5 As shown, different gain values ​​are presented in curve distribution and color distribution respectively.

[0046] The gain reaches 13.46dB in the 5.8GHz frequency band, meeting the resonance requirements.

[0047] In one embodiment, the reflective array is composed of a plurality of reflective array units based on artificial electromagnetic metamaterial phase shift units; the structure of the reflective array unit includes: a structure in which three layers of metal conductors overlap with two layers of dielectrics;

[0048] Among them, the material of the metal conductor is copper; the medium is a Rogers circuit board, for example, the Rogers circuit board can be Rogers RT5880; the length and width of each reflective array unit are the same; the structure of each reflective array unit is composed of a conductor metal plane, a first dielectric layer, a first U-shaped conductor metal structure, a second dielectric layer and a second U-shaped conductor metal structure, and the relative arrangement of the structure is conductor metal plane, first dielectric layer, first U-shaped conductor metal structure, second dielectric layer and second U-shaped conductor metal structure.

[0049] Among them, the side lengths of the first U-shaped conductor metal structure and the second U-shaped conductor metal structure are different. Generally speaking, the structures of each reflector array unit are, from back to front, a conductor metal plane, a first dielectric layer, a first U-shaped conductor metal structure, a second dielectric layer, and a second U-shaped conductor metal structure. Moreover, the side length of the outer circle of the first U-shaped conductor metal structure is greater than or equal to the side length of the inner circle of the first U-shaped conductor metal structure, and the side length of the outer circle of the second U-shaped conductor metal structure is greater than or equal to the side length of the inner circle of the second U-shaped conductor metal structure. In an embodiment, the size of the two-layer U-shaped conductor metal structure can provide a degree of freedom for adjusting the phase of the incident wave, greatly improving the phase shift capability.

[0050] In order to further improve the antenna gain, the reflector array can adopt a reflector array unit based on an artificial electromagnetic metamaterial phase shift unit. The reflector array uses the reflection of electromagnetic waves to correct the phase of the electromagnetic waves emitted by the feed antenna to the reflector surface and then reflect them out. Since the feed antenna is a spherical wave before reflection, the reflector surface can perform phase compensation on the spherical wave, thereby converting the spherical wave into a plane wave to improve energy efficiency. In an embodiment, the reflector array focal length can be designed to be F=500mm (i.e., the relative distance between the center point of the aperture surface of the feed antenna and the reflector array), the reflector array size is 500mm*500mm, and the array element adopts a structure of 3 layers of metal conductors and 2 layers of dielectrics overlapping, wherein the metal conductor material is copper, the dielectric material is RogersRT5880, and each unit has a length and width of 12.5mm and a height of 10mm. Figure 6 1 is a schematic diagram of the structure of a reflective array unit provided by an embodiment of the present invention. The first dielectric layer is denoted as dielectric layer 1, the first U-shaped conductor metal structure is denoted as U-shaped conductor metal structure 1, the second dielectric layer is denoted as dielectric layer 2, and the second U-shaped conductor metal structure is denoted as U-shaped conductor metal structure 2. Figure 6 As shown, from back to front are respectively a conductor metal plane, a dielectric layer 1, a U-shaped conductor metal structure 1, a dielectric layer 2 and a U-shaped conductor metal structure 2.

[0051] The last layer in the reflector array unit is a conductor metal layer, which can ensure that no electromagnetic waves leak to the rear of the unit after passing through the unit. In order to improve the ability to adjust the phase of the incident wave, the unit reflection wave phase shift covers 0 to 360 degrees, and at the same time consider the thickness of the reflector array to be as thin as possible, a two-layer dielectric structure is selected through simulation. The size of the two-layer U-shaped conductor metal structure provides freedom for adjusting the phase of the incident wave. The structure is simple and easy to process, and the phase shift ability is good. Assume that the outer circle side length of the U-shaped conductor metal structure 1 is w1, the inner circle side length is w2, the outer circle side length of the U-shaped conductor metal structure 2 is w3, and the inner circle side length is w4. The reflection coefficient and phase shift corresponding to the values ​​of each parameter obtained through simulation are shown in Table 1.

[0052] Table 1 Phase shift diagram corresponding to different side lengths

[0053] Serial number w1 w2 w3 w4 phase shift / deg 1 10 9 9.3 2 180 2 10 9 8.5 1 -135 3 10 9 7.5 1 -90 4 10 1.5 6 5 -45 5 10 5 6 5 0 6 11.93 5.96 11.93 5.8 45 7 10 0 9.5 4.5 90 8 10 9 9.4 1 135

[0054] Then the distance D from the feed antenna to a point (x, y) in the reflection array can be expressed as Then the distance difference between the feed antenna to (x, y) and the feed antenna to the center point of the reflector array can be expressed as Then the phase difference between the point (x, y) and the midpoint of the reflection array is Among them, k 0 is the wave number in free space, which indicates the change of the phase of electromagnetic wave with the spatial distance. The phase shift value of the center point of the reflective array is 180 degrees. Then the phase shift value of each point of the reflective array can be calculated. Figure 7 : is a schematic diagram of the phase shift distribution of each reflection array unit on a reflection array provided by an embodiment of the present invention. The entire phase shift range is divided into 8 intervals. By calculating the reflection phase shift value of each point on the reflection array, the units falling in the same phase shift interval are replaced by the median of the interval. The phase shift distribution of each unit on the reflection array can be calculated as follows: Figure 7 shown.

[0055] In this scheme, artificial electromagnetic metamaterial reflection units are designed and combined into an array to adjust the phase of the incident wave of the feed antenna. The feed antenna and the reflector array are fixed by a supporting device, and the degrees of freedom of the reflector array antenna in the pitch angle and yaw angle are increased by a rotating shaft and a turntable. Finally, the feed antenna and the reflector array are allowed to rotate with the drone, ensuring that the drone is always within the coverage of the digital image transmission antenna in the ground station, improving the antenna gain, and overcoming the path loss problem of long-flight drones during long-distance flight.

[0056] Figure 8 Schematic diagram of the overall structure of a digital image transmission antenna provided by an embodiment of the present invention. Figure 8 As shown, the feed antenna adopts a rectangular waveguide horn antenna, and the reflector array adopts an artificial electromagnetic metamaterial phase shift unit to improve the antenna gain of the digital image transmission antenna.

[0057] In one embodiment, Fig. 9 is a structural block diagram of a communication system provided by an embodiment of the present invention. The communication system in this embodiment includes: a drone 910, a ground station 920 and a ground station antenna control device 930;

[0058] The ground station antenna control device 930 establishes a wired connection with the ground station 920, and the ground station 920 establishes a wireless connection with the drone 910 through the ground station antenna control device 930;

[0059] In response to the movement instruction of the UAV 910, the ground station 920 determines the rotation angle to be compensated of the digital image transmission antenna based on the relative distance and relative height difference between the UAV 910 and the ground station 920, and sends the rotation angle to be compensated to the ground station antenna control device 930, so that the control gimbal in the ground station antenna control device 930 adjusts the yaw angle and pitch angle of the digital image transmission antenna according to the rotation angle to be compensated.

[0060] In order to obtain the position of the UAV 910, the digital image transmission antenna as a radio frequency antenna is aligned with the UAV 910 in real time, and the pitch angle and yaw angle of the ground station antenna control device 930 are adjusted in time. The yaw angle and pitch angle of the digital image transmission antenna can be dynamically adjusted through a pre-designed antenna rotation method to ensure that the UAV 910 is always within the coverage range of the digital image transmission antenna as a radio frequency antenna in the ground station 920, thereby improving the antenna gain and overcoming the path loss problem of long-flight UAVs during long-distance flight.

[0061] In one embodiment, Fig.10 is a flow chart of a communication method provided by an embodiment of the present invention. This embodiment is applicable to the case where the gain of the radio frequency antenna of the ground station corresponding to the long-endurance UAV is adjusted. The method can be executed by a communication system, and the communication system can be implemented in the form of hardware and / or software. Fig.10 As shown, the method includes:

[0062] S1010. Determine the rotation angle to be compensated of the digital image transmission antenna in the antenna control device of the ground station based on the relative distance and relative height difference between the UAV and the ground station.

[0063] Among them, the rotation angle to be compensated includes the rotation axis angle to be compensated and the turntable angle to be compensated. Among them, the rotation axis angle to be compensated is used to adjust the pitch angle of the digital image transmission antenna; the turntable angle to be compensated is used to adjust the yaw angle of the digital image transmission antenna. In an embodiment, the ground station calculates the relative distance and relative height difference between the drone and the ground station based on the longitude and latitude; then the pitch angle to be compensated and the yaw angle to be compensated are calculated by the existing formula, and the rotation axis angle to be compensated and the turntable angle to be compensated are sent to the gimbal controller.

[0064] S1020. Send the rotation angle to be compensated to the antenna control device of the ground station through the gimbal controller in the ground station, so that the control gimbal in the antenna control device of the ground station adjusts the yaw angle and pitch angle of the digital image transmission antenna according to the rotation angle to be compensated.

[0065] Among them, the shaft motor can control the rotation direction of the antenna shaft according to the shaft angle to be compensated to adjust the pitch angle of the digital image transmission antenna; the turntable motor controls the rotation direction of the antenna turntable according to the turntable angle to be compensated to adjust the yaw angle of the digital image transmission antenna.

[0066] In an embodiment, the gimbal controller sends the shaft angle to be compensated and the turntable angle to be compensated to the ground station antenna control device, so that the control gimbal in the ground station antenna control device adjusts the pitch angle of the digital image transmission antenna according to the shaft angle to be compensated, and adjusts the yaw angle of the digital image transmission antenna according to the turntable angle to be compensated.

[0067] The technical solution of this embodiment determines the deflection angle of the digital image transmission antenna by the relative position between the UAV and the ground station and the strength of the digital image transmission signal emitted by the UAV, thereby realizing the switching of the image transmission link when the UAV crosses the ground station, improving the stability of the UAV communication link and improving the quality of long-distance communication.

[0068] In one embodiment, the communication method further includes: obtaining, through a gimbal controller in a ground station, an actual signal strength of a digital image transmission signal corresponding to the digital image transmission antenna; when the actual signal strength reaches a preset signal strength threshold, controlling the gimbal controller to stop rotating.

[0069] Assume that the preset signal strength threshold is 25dBm. Of course, in actual operation, the preset signal strength threshold can be adjusted according to the actual situation or user requirements. For example, if the user requirements are high, the preset signal strength threshold can be adjusted accordingly; if the user requirements are low, the preset signal strength threshold can be adjusted accordingly. After the drone takes off, it updates its own position every second, and the ground station records the relative distance between the drone and the ground station in real time. However, the RF antenna angle is not adjusted when the actual signal strength is not less than 25dBm. When the actual signal strength value of the digital image transmission antenna is lower than 25dBm, the ground station calculates the pitch angle and yaw angle that the RF antenna (i.e., the reflector array antenna) needs to compensate based on the positions of the two again, and transmits it to the gimbal controller. The gimbal controller controls the antenna steering and monitors the actual signal strength value at the same time. Stop steering when the actual signal strength value reaches 25dBm. The purpose of this is to prevent the RF antenna from constantly steering and causing aging of the mechanical structure. The RF antenna itself has a certain radiation angle, and can still maintain good signal strength even in the case of incomplete alignment. At the same time, it can ensure that the direction pointed by the RF antenna must be the direction of the drone.

[0070] In one embodiment, the communication method further includes: when the actual signal strength does not reach a preset signal strength threshold and the actual duration is greater than a preset duration threshold, broadcasting a signal requesting a digital image transmission link switch through the drone;

[0071] When the UAV receives the switching permission signal and the UAV position request information returned by each standby ground station in the standby ground station set, the UAV sends its own UAV position information to each to-be-switched ground station in the to-be-switched ground station set through the UAV; wherein the to-be-switched ground station set is a subset of the standby ground station set;

[0072] The actual signal strength value of the digital image transmission signal sent by each to-be-switched ground station in the to-be-switched ground station set is received by the drone, as well as the relative distance between the drone and the drone;

[0073] The drone sends a frequency matching permission message to the ground station to be switched whose actual signal strength value reaches the preset signal strength threshold and whose relative distance is the smallest, so as to establish a communication connection between the drone and the ground station to be switched.

[0074] Among them, the actual duration is used to characterize the duration of the actual signal strength value of the digital image transmission antenna being lower than the preset signal strength threshold; the preset duration threshold refers to the duration threshold value of the actual signal strength value of the pre-configured digital image transmission antenna being lower than the preset signal strength threshold, for example, the preset duration threshold can be 30 seconds (s). In the actual communication process, when the actual signal strength does not reach the preset signal strength threshold and the actual duration is greater than the preset duration threshold, it can be understood that the ground station to which the drone is connected is currently unable to communicate normally with the drone. In order to ensure effective monitoring of the drone, the digital image transmission link of the ground station communicating with the drone can be switched.

[0075] In order to obtain the position of the UAV, the digital image transmission antenna as the RF antenna is aligned with the UAV in real time, the pitch angle and yaw angle of the antenna control device of the ground station are adjusted in time, and the RF antenna angle rotation method based on the signal strength increment is designed.

[0076] First, the ground station returns to its initial position after each startup, ensuring that it can receive the frequency request information from the drone in the air even when it is not connected to the drone. After the drone is powered on, it connects to the ground station at the take-off point, and after the connection, it returns the drone's location information. The ground station obtains its own positioning information and the drone's positioning information.

[0077] The ground station calculates the relative distance and relative height between the drone and the ground station based on the latitude and longitude. The pitch angle and yaw angle are calculated using the existing formula, and the rotation angle is sent to the gimbal controller. While controlling the gimbal's steering, the gimbal controller receives the actual signal strength value of the digital image transmission signal from the digital image transmission antenna, and stops rotating when the actual signal strength value reaches 25dBm.

[0078] After the drone takes off, it updates its position every second, and the ground station records the relative distance between the drone and the ground station in real time. However, the RF antenna angle is not adjusted when the actual signal strength value is not less than 25dBm. When the actual signal strength value of the digital image transmission antenna is lower than 25dBm, the ground station calculates the pitch angle and yaw angle that the RF antenna needs to compensate based on the positions of the two again, and transmits it to the gimbal controller; the gimbal controller controls the steering of the digital image transmission antenna while monitoring the actual signal strength value. Stop steering when the actual signal strength value reaches 25dBm. The purpose of this is to prevent the RF antenna from constantly steering and causing aging of the mechanical structure. The RF antenna itself has a certain radiation angle, and can still maintain good signal strength even when it is not fully aligned. At the same time, it can ensure that the direction the RF antenna points to is definitely the direction of the drone.

[0079] When the actual signal strength value of the digital image transmission antenna received by the RF antenna is lower than 25dBm for more than 30s, the drone automatically reduces the video clarity, and only transmits the drone's posture information back to the ground station, and uses some communication resources to broadcast the digital image transmission link switching signal to the surrounding area.

[0080] After receiving the signal, the standby ground station (i.e., the ground station in an idle state) deployed on the surrounding towers or sites sends a switching permission signal and a signal requesting the location information of the drone.

[0081] After receiving the switching permission signal and the signal requesting the drone's location information, the drone sends its own location information to the first three ground stations (the first three drones that received the switching permission signal first).

[0082] The first three ground stations began to adjust their own yaw and pitch angles to align with the position of the drone. After adjustment, they sent the actual signal strength value of the digital image transmission signal to the drone, as well as the relative distance between them and the drone.

[0083] The drone sends a message allowing frequency binding to the ground station with an actual signal strength value greater than 25dBm and the nearest relative distance (including the ground station that has not been disconnected), and disconnects itself from the previous ground station and enters the frequency binding state. If the signal of the ground station that has not been disconnected recovers to 25dBm and the distance is the nearest, the switching process is stopped.

[0084] When the actual signal strength value is greater than 25dBm and the nearest ground station receives the message allowing the frequency binding, it enters the frequency binding state. The handshake between the two is successful, and the drone realizes the switching of the digital image transmission link.

[0085] It should be noted that there is a risk of message loss in the interaction between the drone and the new ground station. When one party sends a message but does not receive a response, a 1s timeout and three retransmission mechanisms are used to ensure information transmission. At the same time, if the drone does not receive the signal strength and distance message from the next ground station, or if the signal strength received from other ground stations is unqualified, the data transmission link will not be switched.

[0086] In one embodiment, Fig.11 is a structural block diagram of an electronic device provided by an embodiment of the present invention, such as Fig.11 As shown, a schematic diagram of the structure of an electronic device 10 that can be used to implement an embodiment of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0087] like Fig.11 As shown, the electronic device 10 includes at least one processor 11, and a memory connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 to the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, ROM 12 and RAM 13 are connected to each other through a bus 14. The input / output (I / O) interface 15 is also connected to the bus 14. The electronic device 10 of this embodiment can be a ground station of the above-mentioned embodiment.

[0088] A number of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0089] The processor 11 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 performs the various methods and processes described above, such as the communication method.

[0090] In some embodiments, the communication method may be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the communication method described above may be performed. Alternatively, in other embodiments, the processor 11 may be configured to perform the communication method in any other appropriate manner (e.g., by means of firmware).

[0091] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0092] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0093] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0094] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0095] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0096] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0097] An embodiment of the present invention further provides a computer program product, including a computer program, which, when executed by a processor, can implement a communication method as provided in any embodiment of the present application.

[0098] In the process of implementation, the computer program product can be written in one or more programming languages ​​or a combination thereof to perform the computer program code of the present application, and the programming language includes an object-oriented programming language, such as Java, Smalltalk, C++, and also includes a conventional procedural programming language, such as "C" language or similar programming language. The program code can be executed entirely on the user's computer, partially on the user's computer, as an independent software package, partially on the user's computer and partially on the remote computer, or completely on the remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (for example, using an Internet service provider to connect through the Internet).

[0099] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0100] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A ground station antenna control device, characterized in that: include: A digital image transmission antenna and a control pan-tilt platform; wherein the digital image transmission antenna comprises a feed antenna and a reflector array; the feed antenna and the reflector array are both connected to the control pan-tilt platform; the feed antenna is aligned with the center of the reflective array surface of the reflector array; Performing phase compensation on the electromagnetic waves emitted by the feed antenna to the reflection array through the reflection array, so as to convert the spherical electromagnetic waves emitted by the feed antenna into planar electromagnetic waves; The gimbal controller external to the control gimbal responds to the received angle adjustment instruction and adjusts the yaw angle and pitch angle of the digital image transmission antenna according to the rotation angle to be compensated carried in the angle adjustment instruction.

2. The ground station antenna control device according to claim 1, characterized in that: Receiving the rotation angle to be compensated determined by the ground station through the gimbal controller, and controlling the rotation direction of the control gimbal based on the rotation angle to be compensated, so as to adjust the yaw angle and pitch angle of the digital image transmission antenna; When the gimbal controller controls the rotation direction of the control gimbal, the gimbal controller obtains the actual signal strength of the digital image transmission signal emitted by the digital image transmission antenna, and controls the control gimbal to stop rotating when the actual signal strength reaches a preset signal strength threshold.

3. The ground station antenna control device according to claim 1 or 2, characterized in that: The control platform includes a turntable motor, a shaft motor, an antenna turntable, an antenna shaft, a feed antenna support frame, a reflector array support frame and a shaft support frame; the rotation angle to be compensated includes a shaft angle to be compensated and a turntable angle to be compensated; Wherein, the antenna shaft is arranged on the shaft support frame, the shaft support frame is connected to the antenna turntable, and the turntable motor is connected to the antenna turntable; the shaft motor is located in the antenna shaft; the top of the feed antenna support frame is used to fix the feed antenna, the bottom of the feed antenna support frame is connected to the bottom of the reflector support frame, and the rear end of the reflector support frame is connected to the antenna shaft; The shaft motor controls the rotation direction of the antenna shaft according to the shaft angle to be compensated, so as to adjust the pitch angle of the digital image transmission antenna; The turntable motor controls the rotation direction of the antenna turntable according to the turntable angle to be compensated, so as to adjust the yaw angle of the digital image transmission antenna.

4. The ground station antenna control device according to claim 3, characterized in that: The bottom of the feed antenna support frame and the bottom of the reflector array support frame are fixed by a triangular structure; the rear end of the reflector array support frame and the antenna shaft are fixed by a cross structure.

5. The ground station antenna control device according to claim 1 or 2, characterized in that: The feed antenna is any directional antenna selected from the group consisting of a microstrip antenna, a helical antenna, a Yagi antenna and a rectangular waveguide horn antenna.

6. The ground station antenna control device according to claim 1 or 2, characterized in that: The reflective array is composed of a plurality of reflective array units based on artificial electromagnetic metamaterial phase shift units; the structure of the reflective array unit includes: a structure in which three layers of metal conductors overlap with two layers of dielectrics; Among them, the material of the metal conductor is copper; the medium is a Rogers circuit board; the length and width of each of the reflective array units are the same; the structure of each of the reflective array units consists of a conductor metal plane, a first dielectric layer, a first U-shaped conductor metal structure, a second dielectric layer and a second U-shaped conductor metal structure.

7. A communication system, characterized in that: include: An unmanned aerial vehicle, a ground station, and a ground station antenna control device as described in any one of claims 1 to 6; Wherein, the ground station antenna control device establishes a wired connection with the ground station, and the ground station establishes a wireless connection with the drone through the ground station antenna control device; In response to the movement instruction of the UAV, the ground station determines the rotation angle to be compensated of the digital image transmission antenna based on the relative distance and relative height difference between the UAV and the ground station, and sends the rotation angle to be compensated to the antenna control device of the ground station, so that the control gimbal in the antenna control device of the ground station adjusts the yaw angle and pitch angle of the digital image transmission antenna according to the rotation angle to be compensated.

8. A communication method, characterized in that: Applied to the communication system as claimed in claim 7; the method comprising: The ground station determines the rotation angle to be compensated of the digital image transmission antenna in the ground station antenna control device based on the relative distance and relative height difference between the UAV and the ground station; The rotation angle to be compensated is sent to the antenna control device of the ground station through the gimbal controller in the ground station, so that the control gimbal in the antenna control device of the ground station adjusts the yaw angle and pitch angle of the digital image transmission antenna according to the rotation angle to be compensated.

9. The communication method according to claim 8, characterized in that: The method further comprises: Obtaining the actual signal strength of the digital image transmission signal corresponding to the digital image transmission antenna through the gimbal controller in the ground station; When the actual signal strength reaches a preset signal strength threshold, the pan / tilt controller controls the regulating pan / tilt to stop rotating.

10. The communication method according to claim 8, characterized in that: The method further comprises: When the actual signal strength does not reach the preset signal strength threshold and the actual duration is greater than the preset duration threshold, broadcasting a signal for requesting a digital image transmission link switch through the drone; When the UAV receives the switching permission signal and the UAV position request information returned by each standby ground station in the standby ground station set, the UAV sends its own UAV position information to each to-be-switched ground station in the to-be-switched ground station set through the UAV; wherein the to-be-switched ground station set is a subset of the standby ground station set; The actual signal strength value of the digital image transmission signal sent by each to-be-switched ground station in the to-be-switched ground station set is received by the drone, as well as the relative distance between the drone and the drone; The drone sends a frequency matching permission message to the ground station to be switched whose actual signal strength value reaches the preset signal strength threshold and whose relative distance is the smallest, so as to establish a communication connection between the drone and the ground station to be switched.

Images