Aerial optical routing system based on optical intelligent surface and implementation method

Abstract

The invention discloses an optical intelligent surface-based aerial optical routing system and an implementation method, and is characterized in that one or more optical intelligent surfaces are arranged on each optical intelligent aircraft, so that optical signal information from a base station can be reflected step by step through the optical intelligent surfaces and transmitted to the whole optical intelligent aircraft group, and aerial optical routing is realized. The base station emits an optical signal to one or more first-level optical intelligent aircrafts, and the optical signal is transmitted to one or more second-level optical intelligent aircrafts after being split and reflected by the optical intelligent surfaces on the first-level optical intelligent aircrafts. The second-level optical intelligent aircraft is used as a routing node, signals are transmitted to the next-level optical intelligent aircraft through the optical intelligent surface, and then the whole optical intelligent aircraft group is traversed. The optical intelligent surface adopted by the invention is different from an optical relay, does not need to receive an optical signal, but directly performs beam splitting and reflection on the optical signal. According to the invention, the communication delay is very low, the energy efficiency is very high, and the method is an air optical routing scheme with low cost, low delay and high energy efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless communication, and in particular relates to wireless optical communication and optical smart surface technology. Background Art

[0002] With the development and large-scale application of aircraft technologies such as drones and airships, the construction of communication networks between the ground and the air has become the focus of research. However, airborne radio frequency communications have the disadvantages of low energy efficiency and capacity, poor confidentiality, and easy interception. Therefore, people gradually use wireless optical communications with concentrated beam energy and higher confidentiality as a solution for airborne wireless communications.

[0003] However, as the number of aircraft increases, the scale of aircraft networking further expands, and the base station is difficult to support the real-time beam alignment and tracking of a large number of aircraft. At the same time, the position of the aircraft changes rapidly during flight and is far away from the base station. It is also difficult for the base station to obtain the precise position and real-time attitude of each aircraft in real time. This results in some aircraft in the network being unable to receive signals and disconnecting from the base station and other aircraft.

[0004] At the same time, some aircraft may run out of power during flight. Existing wireless energy transmission technology is mainly aimed at base stations and a small number of aircraft. As the number of aircraft increases, a more efficient signal and energy transmission solution needs to be proposed to meet the communication needs of large-scale aerial networking. Summary of the invention

[0005] The purpose of the present invention is to provide an aerial optical routing system and implementation method based on optical intelligent surfaces to solve the problem of high communication delay in aircraft groups and difficult signal transmission in the air. At the same time, high-efficiency laser beams are used for communication, which can also provide energy for aircraft while transmitting signals, thereby improving the endurance of aircraft.

[0006] To achieve the above object, the technical solution adopted by the present invention is: An aerial optical routing system and implementation method based on optical intelligent surfaces are oriented to aerial communication scenarios, and include one or more wireless optical communication base stations, multiple optical intelligent aircraft (drones, airships, airplanes, etc.) and multiple optical intelligent surfaces. By equipping each optical intelligent aircraft with one or more optical intelligent surfaces, the optical signal information from the base station can be reflected step by step through the optical intelligent surface and transmitted to the entire optical intelligent aircraft group, thereby realizing aerial optical routing. In the present invention, the base station transmits an optical signal to one or more first-level optical intelligent aircraft, which is then transmitted to one or more second-level optical intelligent aircraft after being split and reflected by the optical intelligent surface on the first-level optical intelligent aircraft. As a routing node, the second-level optical intelligent aircraft can transmit the signal to the optical intelligent aircraft of the next level through the optical intelligent surface, thereby traversing the entire optical intelligent aircraft group.

[0007] The specific steps are as follows: The aerial optical routing system based on optical intelligent surface consists of one or more wireless optical communication base stations and multiple optical intelligent aircraft (unmanned aerial vehicles, airships, airplanes, etc.) equipped with optical intelligent surfaces. The wireless optical communication base station consists of an optical signal transmitting antenna, a signal processing system, a power control system and an optical signal receiving antenna. The optical intelligent aircraft consists of a frame, a power system, a control system and an optical intelligent surface. The frame includes a fuselage and a landing gear. The power system includes a motor, a battery, an optical power amplifier module, and a photoelectric conversion module. The control system includes an image recognition and processing module, a flight control module, a photosensitive module, and an optical intelligent surface instruction generation module. The optical intelligent surface includes an optical intelligent control unit, an optical intelligent surface signal processing module and an optical intelligent surface control module.

[0008] Step 1: Each first-level optical intelligent aircraft determines the relative position of surrounding base stations and other optical intelligent aircraft according to the image recognition and processing module. At the same time, according to the position information of image recognition, the flight control module adjusts the attitude and direction of the optical intelligent aircraft, and the optical intelligent surface instruction generation module generates the initial instruction of the optical intelligent surface, and determines the initial beam deflection and splitting of the optical intelligent surface.

[0009] Step 2: The wireless optical communication base station transmits an optical signal to one or more first-level optical intelligent aircraft, and the signal is irradiated on the optical intelligent surface of the first-level optical intelligent aircraft. The signal is not received and processed, but is directly reflected to the second-level optical intelligent aircraft through the optical intelligent surface.

[0010] Step 3: After receiving the high-intensity signal beam, the photosensitive module of the second-level optical intelligent aircraft is activated, and the position of the surrounding optical intelligent aircraft is determined according to the image recognition and processing module. According to the relative position, the flight control module adjusts the attitude and orientation of the optical intelligent aircraft, and the optical intelligent surface instruction generation module gives the optical intelligent surface instructions, adjusts the optical intelligent surface beam deflection and beam splitting, and routes the optical signal to the adjacent next-level optical intelligent aircraft.

[0011] Step 4: When all optical intelligent aircraft in the network receive the optical signal, each optical intelligent aircraft adjusts the output beam of the optical intelligent surface in real time according to the intensity of the light received by the photosensitive module and the position information of the optical intelligent aircraft obtained by the image recognition and processing module to maintain the link of the optical communication link. This system also supports duplex communication. Since the optical path is reversible, the optical intelligent aircraft transmits the uplink signal (different wavelength to avoid crosstalk) along the original receiving optical path, which can reach the wireless optical communication base station after being reflected by multiple optical intelligent surfaces, thereby realizing duplex communication.

[0012] Step 5: Although the optical intelligent aircraft in the system of the present invention does not need to receive and process the optical signal, since the system uses an energy-concentrated highly directional light beam for transmission, the optical intelligent aircraft can receive the energy of the light beam for endurance. The optical intelligent aircraft can be equipped with an optical power amplifier module and a photoelectric conversion module to receive part of the optical signal energy for its own endurance.

[0013] Beneficial effects: Compared with the traditional relay-based optical routing system, the system of the present invention is more suitable for optical routing of aerial users, and the energy efficiency, degree of freedom and robustness of the system are greatly improved. Different from the traditional air-to-ground optical communication that relies on the alignment of the base station beam, the present invention reduces the burden on the base station end, and its implementation is simpler, more stable and efficient.

[0014] The specific manifestations are as follows: 1. In the system of the present invention, the aircraft does not need to receive and transmit optical signals, but directly transmits them through reflection from the optical smart surface, thereby greatly reducing the system's latency and cost and improving the system's energy efficiency.

[0015] 2. Different from the optical routing with fixed paths using optical relays, the direction, shape, number of beam splitting, etc. of the light beam output by the optical intelligent surface in the system of the present invention can be freely adjusted in real time, thereby further improving the degree of freedom of the optical routing, making it possible to freely adjust the state of the light beam according to the real-time movement status of the optical intelligent aircraft.

[0016] 3. In the system of the present invention, duplex links can share a set of equipment. Since the reflection light path of the optical smart surface is reversible, the duplex communication in the system of the present invention can be based on a set of optical smart surface equipment, which does not need to be separated in space, thereby reducing the cost and load of the system.

[0017] 4. In this invention, the base station only needs to transmit the optical signal to the first-level optical intelligent aircraft, which can then route it to the rest of the optical intelligent aircraft in the network. Different from the traditional air-to-ground optical communication that relies on the alignment of the base station beam, the burden on the base station in this invention is greatly reduced, and the alignment and adjustment of the beam are transferred to each optical intelligent surface.

[0018] 5. The complexity of the entire system is relatively low. The wireless optical communication base station, optical intelligent aircraft and the optical intelligent surface they are equipped with are all supported by mature existing technologies and are very easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a block diagram of the structure of the aerial optical routing system based on the optical smart surface; Figure 2 It is a block diagram of the structure of a wireless optical communication base station; Figure 3This is the structural diagram of the optical intelligent aircraft; Figure 4 This is a schematic diagram of the optical smart surface unit control Figure 5 It is a schematic diagram of the routing beam adjustment of the optical intelligent aircraft. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the accompanying drawings.

[0021] The aerial optical routing system based on optical intelligent surface is composed of one or more wireless optical communication base stations and multiple optical intelligent aircraft (unmanned aerial vehicles, airships, airplanes, etc.) equipped with optical intelligent surfaces. The overall system block diagram of the present invention is as follows: Figure 1 As shown in the figure. Among them, the structure block diagram of the wireless optical communication base station is as follows Figure 2 As shown in the figure, the structural block diagram of the optical intelligent aircraft is as follows Figure 3 shown.

[0022] The wireless optical communication base station is composed of an optical signal transmitting antenna, a signal processing system, a power control system and an optical signal receiving antenna. The optical signal transmitting antenna is connected to the power control system and the signal processing system. The power control system is connected to the optical signal transmitting antenna and the signal processing system. The signal processing system is connected to the optical signal transmitting antenna, the power control system and the optical signal receiving antenna. The optical signal receiving antenna is connected to the signal processing system.

[0023] The optical intelligent aircraft consists of a frame, a power system, a control system and an optical intelligent surface. The frame includes a fuselage and landing gear. The power system includes a motor, a battery, an optical power amplifier module, a photoelectric conversion module, an electronic speed regulator, and a flight control module. The control system includes an image recognition and processing module, a photosensitive module, and an optical intelligent surface signal generation module. The optical intelligent surface includes an optical intelligent control unit, an optical intelligent surface signal processing module, and an optical intelligent surface control module. Among them, the landing gear is connected to the fuselage; the fuselage is connected to the motor; the motor is connected to the fuselage, the flight control module and the battery; the battery is connected to the motor and the photoelectric conversion module; the photoelectric conversion module is connected to the battery and the optical power amplifier module; the flight control module is connected to the signal processing module, the electronic speed regulator and the motor; the optical power amplifier module is connected to the photosensitive module and the photoelectric conversion module; the photosensitive module is connected to the signal processing module and the optical power amplifier module; the signal processing module is connected to the photosensitive module, the image recognition and processing module and the optical intelligent surface signal generation module; the optical intelligent surface signal generation module is connected to the signal processing module and the optical intelligent surface signal processing module; the optical intelligent surface signal processing module is connected to the optical intelligent surface signal generation module and the optical intelligent surface control module; the optical intelligent surface control module is connected to the optical intelligent surface signal processing module and the optical intelligent control unit.

[0024] The following focuses on the principles and implementation methods of optical intelligent surfaces. Currently, all optical intelligent surfaces are composed of optical intelligent control units, optical intelligent surface signal processing modules and optical intelligent surface control modules. Each optical intelligent surface is an array composed of many optical intelligent control units, and each optical intelligent control unit is responsible for adjusting the incident light beam. The control instructions are generated by the optical intelligent surface signal generation module in the control system and sent to the optical intelligent surface signal processing module, which is responsible for processing the control instructions from the optical intelligent surface signal generation module. Subsequently, the processed instructions are transmitted to the optical intelligent surface control module, which is responsible for controlling each optical intelligent control unit.

[0025] Existing optical smart surfaces are mainly divided into mirror array type and optical phased array type. Among them, the mirror array type optical smart surface can be realized by micro-electromechanical system (MEMS) technology, and its physical structure includes multiple miniature mirrors. Each micro-mirror can be regarded as an optical smart control unit. The deflection of each micro-mirror is controlled by the optical smart surface signal processing module and the optical smart surface control module, so as to realize the overall output beam control of the optical smart surface. The MEMS models that can be used as mirror type optical smart surfaces include two-dimensional quasi-static driven micro-mirror array (MMA), translational scanning MEMS micro-mirror developed by Fraunhofer IPMS, and magnetically driven scanning MEM micro-mirror developed by Nippon Signal. The optical phased array type optical metasurface can be realized by a spatial light modulator (SLM), and its physical structure includes multiple optical phased modulation units. Here, each optical phased modulation unit can be regarded as an optical smart control unit. The output phase of the beam of each phased unit is controlled by the optical smart surface signal processing module and the optical smart surface control module, so as to realize the overall output beam shaping and control of the optical smart surface. Currently, the SLM models that can be used as optical phased array optical smart surfaces include the E19x12SLM and 1436Hz frame rate SLM of Meadowlark in the United States, and the GAEA-2, PLUTO-2.1, LUNA, LETO-3, LC2012 of Holoeye in Germany.

[0026] Each step is described in more detail below with reference to the accompanying drawings.

[0027] In step 1, each first-level optical intelligent aircraft determines the relative position of surrounding base stations and other optical intelligent aircraft according to the image recognition and processing module. At the same time, according to the position information of image recognition, the flight control module adjusts the posture and orientation of the optical intelligent aircraft, and the optical intelligent surface instruction generation module generates the initial instruction of the optical intelligent surface to determine the initial beam deflection and beam splitting of the optical intelligent surface. Here, the adjustment of the optical intelligent surface beam deflection based on the position information described in step 1 corresponds to different optical intelligent surface control algorithms according to different types of optical intelligent surfaces.

[0028] The following takes the mirror array optical smart surface as an example to introduce the adjustment algorithm of the optical smart surface based on position information: like Figure 4 As shown, when the output beam of the optical smart surface is aligned with the target at position When the optical smart surface is used, it needs to adjust the rotation angle of each optical smart control unit to deflect the light beam to the user, thereby achieving light beam control. Assume that the optical smart surface consists of The center coordinates of the optical intelligent control unit in the i-th row and j-th column are . The original direction vector of its normal vector for The signal beam from the base station travels a certain distance to the optical smart surface on the first-level optical smart aircraft. Due to the divergence angle of the beam, the optical smart surface receives a diffuse light spot. Assuming that the direction vector of the incident beam is s for , the coordinates of the receiver center are Then, according to the geometric relationship, the direction vector of the normal vector of the optical intelligent control unit in the i-th row and j-th column after deflection can be derived: for

[0029] in,

[0030] Therefore, the deflection angle of the optical intelligent control unit in the i-th row and j-th column can be derived: for

[0031] At the same time, the rotation axis direction vector of the normal vector can be derived for

[0032] Finally, the rotation matrix of the optical intelligent control unit in the i-th row and j-th column can be derived for

[0033] Step 2: The wireless optical communication base station transmits an optical signal to one or more first-level optical intelligent aircraft, and the signal is irradiated on the optical intelligent surface of the first-level optical intelligent aircraft. Here, the optical signal is not received and processed, but is directly reflected to the second-level optical intelligent aircraft through the optical intelligent surface. Since the optical intelligent surface can split the incident light, during the reflection process, a single beam of incident light can be converted into multiple beams of outgoing light pointing to multiple next-level optical intelligent aircraft.

[0034] Step 3: After receiving the high-intensity signal beam, the photosensitive module of the second-level optical intelligent aircraft is activated, and the position of the surrounding optical intelligent aircraft is determined according to the image recognition and processing module. According to the relative position, the flight control module adjusts the attitude and orientation of the optical intelligent aircraft, and the optical intelligent surface instruction generation module gives the optical intelligent surface instructions, adjusts the optical intelligent surface beam deflection and beam splitting, and routes the optical signal to the adjacent next-level optical intelligent aircraft. And so on, so that the optical signal traverses the entire aircraft network.

[0035] Step 4: After all optical intelligent aircraft in the network receive the optical signal, each optical intelligent aircraft adjusts the output beam of the optical intelligent surface in real time according to the intensity of the light received by the photosensitive module and the position information of the optical intelligent aircraft obtained by the image recognition and processing module to maintain the connection of the optical communication link. Figure 5 As shown, each optical intelligent aircraft has an optical routing range. When the next-level optical intelligent aircraft enters the range, it needs to add split beams to enable the target to access the communication. Similarly, when the next-level optical intelligent aircraft leaves the range, it needs to delete the split beams to save energy. This system also supports duplex communication. Since the optical path is reversible, the optical intelligent aircraft transmits the uplink signal (different wavelengths to avoid crosstalk) along the original receiving optical path, and it can reach the wireless optical communication base station after being reflected by multiple optical intelligent surfaces, thereby realizing duplex communication.

[0036] Step 5: Although the optical intelligent aircraft in the system of the present invention does not need to receive and process the optical signal, since the system uses energy-concentrated high-directional light beams for transmission, the optical intelligent aircraft can receive the energy of the light beam for endurance. The optical intelligent aircraft is equipped with a photosensitive module, an optical power amplifier module and a photoelectric conversion module. The optical intelligent aircraft receives part of the light signal energy through the photosensitive module, which is processed by the optical power amplifier module and then reaches the photoelectric conversion module to be converted into electrical energy to supply the aircraft for operation.

[0037] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An aerial optical routing system based on optical smart surface, characterized in that: It includes a wireless optical communication base station and a group of optical intelligent aircraft; each optical intelligent aircraft is equipped with an optical intelligent surface; the optical intelligent aircraft in the group are divided into multiple levels; the optical signal information from the wireless optical communication base station is reflected level by level through the optical intelligent surface and transmitted to the entire group of optical intelligent aircraft, thereby realizing aerial optical routing.

2. The aerial optical routing system based on optical smart surface according to claim 1, characterized in that: The optical intelligent aircraft is equipped with a power system, a control system and an optical intelligent surface; the power system includes a flight control module; the control system includes a photosensitive module, an image recognition and processing module, an optical intelligent surface signal generation module and a signal processing module; the optical intelligent surface includes an optical intelligent regulation unit, an optical intelligent surface signal processing module and an optical intelligent surface control module; After the photosensitive module receives the light signal, the control system is activated, the image recognition and processing module determines the position of the surrounding optical intelligent aircraft, the signal processing module sends a flight instruction to the flight control module according to the relative position, and the flight control module adjusts the attitude and direction of the optical intelligent aircraft. The signal processing module controls the optical intelligent surface signal generation module according to the relative position to generate and send a control instruction to the optical intelligent surface signal processing module, and the optical intelligent surface signal processing module processes the control instruction; the processed control instruction is transmitted to the optical intelligent surface control module, which is responsible for controlling the optical intelligent regulation unit, and the optical intelligent regulation unit is responsible for regulating the incident light beam.

3. The aerial optical routing system based on optical intelligent surface according to claim 2, characterized in that: The optical intelligent aircraft is also equipped with an optical power amplifier module and a photoelectric conversion module. The optical intelligent aircraft receives part of the light signal energy through the photosensitive module, which is processed by the optical power amplifier module and then reaches the photoelectric conversion module to be converted into electrical energy to supply the optical intelligent aircraft for operation.

4. The aerial optical routing system based on optical smart surface according to claim 1, characterized in that: The optical intelligent aircraft transmits an uplink signal along the original receiving optical path, and the uplink signal is reflected by multiple optical intelligent surfaces to reach the wireless optical communication base station, thereby realizing duplex communication.

5. The aerial optical routing system based on optical smart surface according to claim 1, characterized in that: The optical intelligent surface can split the incident light, so that a single incident light beam is converted into multiple outgoing light beams pointing to multiple next-level optical intelligent aircraft.

6. The aerial optical routing system based on optical intelligent surface according to claim 2, characterized in that: When all the optical intelligent aircraft in the network receive the optical signal, each optical intelligent aircraft adjusts the output light beam of the optical intelligent surface in real time according to the intensity of the light received by the photosensitive module and the position information of the optical intelligent aircraft obtained by the image recognition and processing module to maintain the link of the optical communication link.

7. The aerial optical routing system based on optical smart surface according to claim 2, characterized in that: The optical smart surface is of mirror array type, and its physical structure includes multiple micro mirrors. Each micro mirror is regarded as an optical intelligent control unit. The deflection of each micro mirror is controlled by the optical intelligent surface signal processing module and the optical intelligent surface control module, thereby realizing the overall output beam control of the optical intelligent surface.

8. A method for implementing air optical routing based on the air optical routing system according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: a wireless optical communication base station transmits an optical signal to one or more first-level optical intelligent aircrafts, and the optical signal is transmitted to one or more second-level optical intelligent aircrafts after being split and reflected by an optical intelligent surface on the first-level optical intelligent aircrafts; The second-level optical intelligent aircraft acts as a routing node, transmitting the signal to the next-level optical intelligent aircraft through the optical intelligent surface, and then traverses the entire optical intelligent aircraft group.

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