Self-adaptive Beidou short message emergency remote control and telemetering method

Abstract

The invention discloses a self-adaptive Beidou short message emergency remote control and telemetering method. The method comprises the following steps: identifying the communication length and the frequency level of Beidou short message equipment on a host machine; determining a telemetering transmission scheme, and filling downlink data frames; determining a remote control transmission scheme, and receiving and filling uplink remote control data frames; establishing a telemetering sending task, periodically and cyclically inquiring whether the sending countdown of the Beidou short message is 0 or not by the telemetering sending task, if so, sending a downlink data frame, and if not, quitting and waiting for next inquiry; and establishing a remote control receiving task, regularly querying whether the asynchronous communication interface connected with the short message equipment receives data or not by the remote control receiving task, storing the received data into a buffer area, and extracting a complete uplink remote control data frame according to a frame header, a frame tail and frame verification. The method can adapt to different levels of Beidou short message communication frequencies and length levels, is high in program adaptability, and can automatically match the maximum communication transmission capability when the level of the user card changes.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) control technology, and more specifically, to an adaptive BeiDou short message emergency remote control and telemetry method. Background Technology

[0002] With the development of technology, medium and large-sized UAVs are becoming increasingly faster and have longer flight ranges and endurances. Various forms and frequency bands of communication links are being applied to UAVs. Wireless telemetry and control links are the lifeline for UAVs. A complete telemetry and control link not only allows ground control stations to monitor the UAV's status in real time, but also enables them to control the aircraft to successfully complete missions and return safely. Once the wireless telemetry and control link is interrupted, the ground control station will lose contact with the UAV, and the UAV will be unable to continue its mission, initiating an emergency return-to-home procedure. Wireless links include line-of-sight (Line-of-Sight) links and beyond-Line-of-Sight (BLS) links. Line-of-sight links have low latency but limited range, typically within a few hundred kilometers, and are affected by the Earth's curvature and obstacles. This is clearly insufficient for UAVs with a range of thousands of kilometers. Therefore, UAVs are usually equipped with BLS links for performing BLS missions. BLS links have a long range, theoretically providing global coverage. BLS links include satellite relay links and airborne platform relay links. Currently, satellite relay links are widely used in medium and large-sized long-endurance UAVs. However, equipment failures, extreme weather, and dense cloud cover can also cause short-term or complete interruptions to satellite communication links. With the development and improvement of the BeiDou Navigation Satellite System, BeiDou short message emergency communication, as a new type of communication method, is increasingly being used in both civilian and military fields. Installing BeiDou short message communication as a communication link on UAVs can increase the redundancy of wireless communication telemetry and control links, enhance the UAV's mission execution capabilities, and improve flight safety. UAVs include flight control, navigation, power, fuel, electrical, landing gear, environmental control, fire control, and mission payload systems. As UAVs become larger and more capable of performing missions, the systems become increasingly complex. The amount of telemetry information and remote control commands generated by UAVs also increases. The growing demand for telemetry data and high data refresh rates from ground control stations clashes with the bandwidth limitations of wireless communication links. How to fully utilize limited wireless transmission bandwidth to transmit more and faster data is a challenge that system design must address.

[0003] Therefore, it is necessary to develop an adaptive BeiDou short message emergency remote control and telemetry method.

[0004] The information disclosed in the background section of this invention is intended only to enhance the understanding of the general background of this invention, and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] This invention proposes an adaptive BeiDou short message emergency remote control and telemetry method, which can adapt to different levels of BeiDou short message communication frequency and length, has strong program adaptability, and can automatically match the maximum communication transmission capacity when the user card level changes.

[0006] This disclosure provides an adaptive BeiDou short message emergency remote control and telemetry method, including: Identify the communication length and frequency level of the BeiDou short message service on the host machine; Determine the telemetry transmission scheme and fill in the downlink data frames; Determine the remote control transmission scheme, receive and fill up the uplink remote control data frames; Establish a telemetry transmission task. The telemetry transmission task periodically checks whether the countdown for sending BeiDou short messages is 0. If it is 0, it sends downlink data frames. If it is not 0, it exits and waits for the next query. A remote control receiving task is established. The remote control receiving task periodically queries whether the asynchronous communication interface connected to the short message device has received data. The received data is stored in a buffer, and the complete uplink remote control data frame is retrieved based on the frame header, frame tail, and frame checksum.

[0007] Preferably, the length level is the maximum number of bytes that can be transmitted in each short message.

[0008] Preferably, the frequency level is the shortest time interval for sending short message messages.

[0009] Preferably, determining the telemetry transmission scheme and filling the downlink data frame includes: Identify multiple telemetry data frames and dedicated downlink telemetry frames for short messages; Before transmitting data, determine whether there are any remaining bytes after the short message dedicated downlink telemetry frame. If so, transmit the telemetry data frame together with the short message dedicated downlink telemetry frame; otherwise, transmit only the short message dedicated downlink telemetry frame.

[0010] Preferably, if there are remaining bytes after the short message dedicated downlink telemetry frame, then the number of remaining frames is calculated: Number of bytes in a short message-dedicated downlink telemetry frame + m The number of bytes in a telemetry data frame is less than or equal to L_Class. Where m is the number of remaining frames and L_Class is the length level.

[0011] Preferably, if m ≥ the total number of telemetry data frames, then all telemetry data frames are transmitted together with the short message dedicated downlink telemetry frames; If 1 < m < the total number of telemetry data frames, then m telemetry data frames and short message dedicated downlink telemetry frames are transmitted sequentially and periodically. If 0 ≤ m < 1, then only short message-specific downlink telemetry frames are transmitted.

[0012] Preferably, determining the remote control transmission scheme and receiving and filling up the uplink remote control data frame includes: The number of bytes for each instruction is determined, with uplink instruction type occupying 1 byte and uplink remote control and telemetry instruction code occupying 2 bytes. Five repetitions of the code are used to provide 10 bytes to prevent wireless transmission interference errors. The number of instructions is determined based on the number of bytes in the short message.

[0013] Preferably, if the communication length level is high, multiple uplink short messages are sent at once.

[0014] Its beneficial effects are as follows: BeiDou short message service can supplement line-of-sight links and satellite communication links, serving as an emergency communication and telemetry link for UAVs in emergencies. This improves the UAV's ability to perform missions in complex situations and enhances its survivability. This method automatically adapts to different levels of BeiDou short message service; no program modification is required when the BeiDou short message user card level changes, demonstrating strong program adaptability. This method fully utilizes the upper limit of data transmission capacity of BeiDou short message service, maximizing its capabilities as a telemetry link to meet the remote control and telemetry needs of UAVs.

[0015] The method of the present invention has other features and advantages that will be apparent from or will be set forth in detail in the accompanying drawings and following detailed description, which together serve to explain the particular principles of the invention. Attached Figure Description

[0016] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same parts.

[0017] Figure 1 A flowchart illustrating the steps of an adaptive BeiDou short message emergency remote control and telemetry method according to an embodiment of the present invention is shown. Detailed Implementation

[0018] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0019] To facilitate understanding of the solutions and effects of the embodiments of the present invention, a specific application example is given below. Those skilled in the art should understand that this example is merely for the purpose of understanding the present invention, and any specific details therein are not intended to limit the present invention in any way.

[0020] Example 1

[0021] Figure 1 A flowchart illustrating the steps of an adaptive BeiDou short message emergency remote control and telemetry method according to an embodiment of the present invention is shown.

[0022] like Figure 1 As shown, this adaptive BeiDou short message emergency remote control and telemetry method includes: Step 101: Identify the communication length and frequency level of the BeiDou short message service on the host machine; Step 102: Determine the telemetry transmission scheme and fill in the downlink data frame; Step 103: Determine the remote control transmission scheme, receive and fill uplink remote control data frames; Step 104: Establish a telemetry transmission task. The telemetry transmission task periodically checks whether the countdown for sending BeiDou short messages is 0. If it is 0, a downlink data frame is sent. If it is not 0, the task exits and waits for the next query. Step 105: Establish a remote control receiving task. The remote control receiving task periodically queries whether the asynchronous communication interface connected to the short message device has received data. The received data is stored in a buffer. The complete uplink remote control data frame is retrieved based on the frame header, frame tail, and frame checksum.

[0023] In one example, the length level is the maximum number of bytes that can be transmitted in each short message.

[0024] In one example, the frequency level is the shortest time interval for sending short message messages.

[0025] In one example, determining the telemetry transmission scheme and filling the downlink data frame includes: Identify multiple telemetry data frames and dedicated downlink telemetry frames for short messages; Before transmitting data, determine whether there are any remaining bytes after the short message dedicated downlink telemetry frame. If so, transmit the telemetry data frame together with the short message dedicated downlink telemetry frame; otherwise, transmit only the short message dedicated downlink telemetry frame.

[0026] In one example, if there are remaining bytes after the short message dedicated downlink telemetry frame, the number of remaining frames is calculated: Number of bytes in a short message-dedicated downlink telemetry frame + m The number of bytes in a telemetry data frame is less than or equal to L_Class. Where m is the number of remaining frames and L_Class is the length level.

[0027] In one example, if m ≥ the total number of telemetry data frames, then all telemetry data frames are transmitted together with short message dedicated downlink telemetry frames; If 1 < m < the total number of telemetry data frames, then m telemetry data frames and short message dedicated downlink telemetry frames are transmitted sequentially and periodically. If 0 ≤ m < 1, then only short message-specific downlink telemetry frames are transmitted.

[0028] In one example, determining the remote control transmission scheme and receiving and filling uplink remote control data frames includes: The number of bytes for each instruction is determined, with uplink instruction type occupying 1 byte and uplink remote control and telemetry instruction code occupying 2 bytes. Five repetitions of the code are used to provide 10 bytes to prevent wireless transmission interference errors. The number of instructions is determined based on the number of bytes in the short message.

[0029] In one example, if the communication length level is high, multiple uplink short messages are sent at once.

[0030] Specifically, BeiDou short message service will be installed on UAVs as a third type of telemetry and control link, serving as a redundant backup for line-of-sight links and satellite communication links.

[0031] The system determines and identifies the communication length and frequency class that the BeiDou short message device on the host machine can provide, which are L_Class and F_Class, respectively. The length class L_Class limits the maximum number of bytes that can be transmitted in each short message, and the frequency class F_Class limits the shortest time interval for sending short messages.

[0032] Determine the telemetry transmission scheme and fill the downlink data frames. Each UAV telemetry data frame is 64 bytes long, for a total of 7 frames, designated as ABCDEFG frames. A dedicated short message downlink telemetry frame, designated as T frame, is set up, with a length set to the minimum short message length of 78 bytes, containing only the filtered key parameters of the UAV system. The method for filling the downlink data frames includes: transmitting T frames each time; if there are remaining bytes, calculating the maximum number of normal telemetry data frames that can be accommodated, i.e., 78 + m. 64 ≤ L_Class. If m ≥ 7, then all telemetry data frames T and A~G are transmitted each time; if 0 < m < 7, then T frames are transmitted each time, along with m telemetry data frames transmitted sequentially and periodically, for example, T+A+B+C+D this time, T+E+F+G+A next time, T+B+C+D+E next time, and so on; if m = 0, then only T frames are transmitted each time.

[0033] Determine the remote control transmission scheme, receive and fill uplink remote control data frames; the uplink instruction type of each instruction occupies 1 byte, and the uplink remote control and telemetry instruction encoding occupies 2 bytes. Use 5 repetitions of encoding to provide 10 bytes to prevent wireless transmission interference errors. Each instruction requires a minimum of 11 bytes; a 78-byte short message can hold up to 6 instructions. If the communication length level is high, multiple 78-byte uplink short messages can be sent at once.

[0034] Establish a telemetry transmission task. The telemetry transmission task checks the countdown of BeiDou short message transmission every 200ms. If it is 0, it sends downlink data frames. If it is not 0, it exits and waits for the next query.

[0035] A remote control receiving task is established. This task checks the asynchronous communication interface connected to the short message device every 20ms to see if data has been received. The received data is stored in a buffer, and the complete uplink remote control data frame is retrieved based on the frame header, frame trailer, and frame checksum. To fully utilize each opportunity to send uplink remote control messages, the remote control data frame can contain up to 6 uplink commands at a time, with each command executed 200ms apart, allowing sufficient time for state switching for the UAV flight control system.

[0036] Those skilled in the art should understand that the above description of the embodiments of the present invention is only intended to illustrate the beneficial effects of the embodiments of the present invention, and is not intended to limit the embodiments of the present invention to any of the examples given.

[0037] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. An adaptive BeiDou short message emergency remote control and telemetry method, characterized in that, include: Identify the communication length and frequency level of the BeiDou short message service on the host machine; Determine the telemetry transmission scheme and fill in the downlink data frames; Determine the remote control transmission scheme, receive and fill up the uplink remote control data frames; Establish a telemetry transmission task. The telemetry transmission task periodically checks whether the countdown for sending BeiDou short messages is 0. If it is 0, it sends downlink data frames. If it is not 0, it exits and waits for the next query. A remote control receiving task is established. The remote control receiving task periodically queries whether the asynchronous communication interface connected to the short message device has received data. The received data is stored in a buffer, and the complete uplink remote control data frame is retrieved based on the frame header, frame tail, and frame checksum.

2. The adaptive BeiDou short message emergency remote control and telemetry method according to claim 1, wherein, The length level is the maximum number of bytes that can be transmitted in each short message.

3. The adaptive BeiDou short message emergency remote control and telemetry method according to claim 1, wherein, The frequency level is the shortest time interval for sending short message messages.

4. The adaptive BeiDou short message emergency remote control and telemetry method according to claim 1, wherein, Determine the telemetry transmission scheme and fill the downlink data frame, including: Identify multiple telemetry data frames and dedicated downlink telemetry frames for short messages; Before transmitting data, determine whether there are any remaining bytes after the short message dedicated downlink telemetry frame. If so, transmit the telemetry data frame together with the short message dedicated downlink telemetry frame; otherwise, transmit only the short message dedicated downlink telemetry frame.

5. The adaptive BeiDou short message emergency remote control and telemetry method according to claim 4, wherein, If there are remaining bytes after the short message dedicated downlink telemetry frame, then calculate the number of remaining frames: Number of bytes in a short message-dedicated downlink telemetry frame + m The number of bytes in a telemetry data frame is less than or equal to L_Class. Where m is the number of remaining frames and L_Class is the length level.

6. The adaptive BeiDou short message emergency remote control and telemetry method according to claim 5, wherein, If m ≥ the total number of telemetry data frames, then all telemetry data frames are transmitted together with the short message dedicated downlink telemetry frames; If 1 < m < the total number of telemetry data frames, then m telemetry data frames and short message dedicated downlink telemetry frames are transmitted sequentially and periodically. If 0 ≤ m < 1, then only short message-specific downlink telemetry frames are transmitted.

7. The adaptive BeiDou short message emergency remote control and telemetry method according to claim 1, wherein, Determine the remote control transmission scheme, and receive and fill uplink remote control data frames, including: The number of bytes for each instruction is determined, with uplink instruction type occupying 1 byte and uplink remote control and telemetry instruction code occupying 2 bytes. Five repetitions of the code are used to provide 10 bytes to prevent wireless transmission interference errors. The number of instructions is determined based on the number of bytes in the short message.

8. The adaptive BeiDou short message emergency remote control and telemetry method according to claim 7, wherein, If the communication length level is high, multiple uplink short messages will be sent at once.

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