Flight control link measurement and control switching method and system

Abstract

The present application relates to a kind of flight control link measurement and control switching method and system, belong to unmanned vehicle communication technical field, method includes in flight control end and ground end configuration multiple measurement and control links;Flight control end is synchronized by multiple measurement and control links and issues telemetry downlink data to ground end;Ground end real-time acquisition multiple measurement and control links transmission state parameters, and based on the transmission state parameters to the multiple measurement and control links are judged state;Wherein, ground end default is through the first transmission mode and uploads remote control uplink data to flight control end;When satisfying first condition, ground end switches to be through the second transmission mode and uploads remote control uplink data to flight control end, and based on the transmission state parameters continuously judges whether satisfying second condition, when satisfying second condition, ground end switches back through the first transmission mode and uploads remote control uplink data to flight control end.Solve the problem that the data processing load is big, transmission delay is high and telemetry data is prone to loss in the switching process due to the existing double launch double receiving mode.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) communication technology, and in particular to a method and system for switching flight control link measurement and control. Background Technology

[0002] During the flight control and measurement of UAVs, the reliability of the telemetry and control link directly determines flight safety. A single telemetry and control link is easily affected by factors such as terrain obstruction, electromagnetic interference, and exceeding the transmission distance limit, which can easily lead to the loss of remote control commands and interruption of telemetry data. In severe cases, it can cause the UAV to lose control and crash.

[0003] In existing technologies, the mode of dual transmission and dual reception of full data by both the flight controller and the ground station causes data redundancy and congestion, increases the data processing load of the flight controller and the ground station, and leads to increased transmission latency; the switching logic is chaotic, which easily leads to problems such as repeated reception of remote control commands and disordered telemetry data display; relying on the flight controller to make link decision switching increases the computational pressure of the flight controller, affects the flight control stability of the flight controller core, and cannot achieve accurate and smooth switching between primary and backup links, making it difficult to meet the high reliability measurement and control requirements of UAVs. Summary of the Invention

[0004] Based on the above analysis, the embodiments of the present invention aim to provide a flight control link telemetry and control switching method and system to solve the problems of high data processing load, high transmission delay, and easy loss of telemetry data during the switching process caused by the existing dual-transmitter dual-receiver mode.

[0005] On one hand, the present invention provides a method for switching between flight control link measurement and control, including: Multiple telemetry and control links are configured at the flight control end and the ground end, including a primary telemetry and control link and at least one backup telemetry and control link; The flight control unit synchronously transmits telemetry downlink data to the ground unit through multiple telemetry and control links; The ground terminal collects the transmission status parameters of multiple telemetry and control links in real time, and determines whether the link status meets the first condition based on the transmission status parameters; wherein, the ground terminal uploads remote control uplink data to the flight control terminal by default through the first transmission method; When the link status meets the first condition, the ground end switches to uploading remote control uplink data to the flight controller via the second transmission method, and continuously judges whether the link status meets the second condition based on the transmission status parameters. When the second condition is met, the ground end switches back to uploading remote control uplink data to the flight controller via the first transmission method.

[0006] Furthermore, the status of the multi-channel telemetry and control link includes normal, deteriorated, and faulty; The first condition is: the status of the primary measurement and control link is degraded or faulty, and at least one backup measurement and control link is in normal status; The second condition is: the link status of the primary measurement and control link is normal, and the duration of the normal status exceeds the preset duration, wherein the criterion for judging the normal status is that the quality score is greater than or equal to the preset quality score threshold.

[0007] Furthermore, the first transmission method is as follows: the ground end uses the primary telemetry and control link as the current communication link, and the ground end uploads remote control uplink data to the flight control terminal through the primary telemetry and control link; the second transmission method is as follows: the ground end selects a backup telemetry and control link as the current communication link, and the ground end uploads remote control uplink data to the flight control terminal through the backup telemetry and control link.

[0008] Furthermore, when the first condition or the second condition is met, the method further includes: The ground terminal stores the remote control uplink data into a buffer queue according to the generation time sequence of the remote control uplink data; After the transmission mode switch is completed, the ground terminal retransmits the remote control uplink data in the buffer queue to the flight controller terminal through the current communication link.

[0009] Furthermore, the ground end selects a backup telemetry and control link as the current communication link, including: When the number of backup telemetry and control links is 1, select that backup telemetry and control link as the current communication link; When the number of backup telemetry and control links is greater than 1, the backup telemetry and control links are sorted according to the link quality score of each backup telemetry and control link. Based on the ranking results, the backup monitoring and control link with the highest link quality score is determined as the current communication link; when there are multiple backup monitoring and control links with the highest link quality score, one backup monitoring and control link is selected as the current communication link according to a preset priority rule. The default priority rule is: Prioritize using the backup telemetry and control link with higher signal strength as the current communication link; If the signal strengths are the same, the backup telemetry and control link with a higher signal-to-noise ratio shall be selected as the current communication link. If the signal-to-noise ratio is the same, the backup telemetry and control link with the lower data packet loss rate is selected as the current communication link.

[0010] Furthermore, retransmitting the remote control uplink data in the buffer queue to the flight controller via the current communication link includes: A list of confirmation commands is generated based on the confirmation frames returned by the flight controller and the sequence number and checksum carried in the remote control uplink data in the buffer queue. Based on the confirmed instruction list, filter the remote control uplink data that has been successfully received by the flight controller in the cache queue to obtain the set of instructions to be resent. Calculate the retransmission rate based on the current transmission latency and data packet loss rate of the communication link; According to the retransmission rate, the remote control uplink data in the set of commands to be retransmitted is sent to the flight controller through the current communication link.

[0011] Further, according to the retransmission rate, sending the remote control uplink data in the set of commands to be retransmitted to the flight controller via the current communication link includes: Based on the type of remote control uplink data in the set of instructions to be resent, the remote control uplink data in the set of instructions to be resent is sorted to obtain an ordered transmission queue; Based on the order of the ordered transmission queue, remote control uplink data is sent to the flight controller terminal one by one according to the retransmission rate; After each remote control uplink data is sent, the system determines whether the transmission was successful based on the confirmation frame returned by the flight controller. If no confirmation frame is received, the system retransmits the data at the retransmission rate until a confirmation frame is received or the preset number of retransmissions is reached. If no confirmation frame is received after the preset number of retransmissions is reached, the ground terminal executes the preset safety protection strategy.

[0012] Furthermore, the method also includes: The flight controller checks whether the received remote control uplink data matches the preset communication protocol and performs CRC verification on the received remote control uplink data. When the remote control uplink data matches the preset communication protocol and the CRC check passes, the flight controller determines that the received remote control uplink data format is correct and checks whether the control quantity in the remote control uplink data is within the preset threshold range. If the data is within the threshold range, the flight controller determines that the remote control uplink data is valid and identifies the received remote control uplink data as a flight control command. If the remote control uplink data does not match the preset communication protocol, or the CRC check fails, or the remote control uplink data format is incorrect, or the control quantity in the remote control uplink data is not within the preset threshold range, the flight controller determines that the remote control uplink data is invalid and executes the preset safety protection strategy.

[0013] Furthermore, the transmission status parameters include signal strength, data packet loss rate, signal-to-noise ratio, transmission delay, and data bit error rate; the status determination of the multi-channel telemetry and control links based on the transmission status parameters includes: The link quality score of the multi-channel telemetry and control link is calculated based on signal strength, data packet loss rate, signal-to-noise ratio, transmission delay, and data bit error rate, as shown in the following formula; Q = α×S + β×SNR + γ×(1 / T) + δ×(1-E) + ε×(1-L); Where Q is the link quality score, S is the signal strength, SNR is the signal-to-noise ratio, T is the transmission delay, E is the bit error rate, L is the packet loss rate; α, β, γ, δ, and ε are weighting coefficients. Based on the link quality score, the multi-channel telemetry and control links are divided into three states: normal, deteriorated, and faulty.

[0014] On the other hand, the present invention provides a flight control link telemetry and control switching system, comprising: The configuration module is used to configure multiple telemetry and control links at the flight control end and the ground end. The multiple telemetry and control links include a primary telemetry and control link and at least one backup telemetry and control link. The downlink module is used to control the flight control terminal to synchronously transmit telemetry downlink data to the ground terminal through multiple telemetry and control links; The acquisition module is used to control the ground end to acquire the transmission status parameters of multiple telemetry and control links in real time, and to determine whether the link status meets the first condition based on the transmission status parameters; wherein, the ground end uploads remote control uplink data to the flight control end by default through the first transmission method; The switching module is used to switch the ground end to upload remote control uplink data to the flight controller via the second transmission method when the link status meets the first condition, and continuously judge whether the link status meets the second condition based on the transmission status parameters. When the second condition is met, the ground end switches back to uploading remote control uplink data to the flight controller via the first transmission method.

[0015] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: 1. This invention adopts an asymmetric transceiver mechanism to reduce data redundancy and flight control load. The flight control end and the ground end are equipped with multiple telemetry and control links. The flight control end transmits telemetry downlink data to the ground end synchronously through the primary telemetry and control link and the backup telemetry and control link to achieve full hot standby of multiple telemetry. The ground end only uploads remote control uplink data through the current primary link, and the flight control end only receives remote control data from the current primary link. The asymmetric design avoids the problem of repeated reception of remote control commands and redundant data transmission, reduces the data processing pressure of the flight control end, and solves the problems of high flight control data processing load and high transmission delay.

[0016] 2. This invention collects the transmission status parameters of all telemetry and control links in real time from the ground end, performs link quality scoring and status determination, and autonomously completes the decision and execution of primary / backup switching. The flight control end does not need to receive switching commands or participate in link decision-making. During the switching process, the flight control end always synchronously sends telemetry data through all links, and the ground end always synchronously receives telemetry data through all links. Only the remote control upload link changes, which simplifies the control logic of the flight control end and solves the problem of telemetry data loss during the switching process.

[0017] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0018] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. Figure 1 is a schematic flowchart of a flight control link telemetry and control switching method according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a measurement and control link provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of an electronic device provided according to an embodiment of the present invention. Detailed Implementation

[0019] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0020] A specific embodiment of the present invention discloses a method for switching between flight control link measurement and control, such as... Figure 1 As shown.

[0021] A method for switching telemetry and control links in a flight control link includes: S1. Configure multiple telemetry and control links at the flight control end and the ground end, wherein the multiple telemetry and control links include a primary telemetry and control link and at least one backup telemetry and control link; like Figure 2 As shown, the flight control terminal can be a flight control computer installed on the UAV, which is responsible for receiving remote control commands from the ground station and sending the UAV's status data; the ground terminal is the ground control station, which is usually a portable computer or a dedicated remote controller, responsible for sending remote control commands and receiving telemetry data from the UAV.

[0022] Multiple telemetry and control links refer to two or more physically independent communication links, such as wireless data transmission links and 5G cellular links. Typically, the wireless data transmission link is pre-set as the primary telemetry and control link, with the others serving as backup links. The primary telemetry and control link is the default communication link, while the backup links take over communication when the primary link's quality deteriorates or is interrupted. Configuration can be completed through the link management software at both the flight controller and ground terminals. The software presets the link type, communication parameters such as frequency, baud rate, protocol type, and primary / backup relationship.

[0023] S2. The flight control terminal synchronously transmits telemetry downlink data to the ground terminal through multiple telemetry and control links; The flight control unit simultaneously transmits the UAV's telemetry downlink data, including flight altitude, position coordinates, attitude angles, battery level, and engine speed, to the ground station via all configured telemetry and control links. Within each control cycle, the flight control unit packages the collected telemetry data into pre-formatted data frames, copies them multiple times, and sends them to the primary and backup link's transmission buffers. Each link's physical interface, such as an asynchronous RS422 serial port or Ethernet port, operates independently, simultaneously transmitting the same data frames. The corresponding receiving interface on the ground station simultaneously listens to all links, receiving telemetry data frames from different links. This simultaneous transmission from multiple telemetry and control links ensures that even if one link experiences a momentary failure, the ground station can still obtain complete telemetry data from other links, achieving multi-channel hot backup. The flight control unit does not need to perform judgment, saving its computing resources.

[0024] S3. The ground end collects the transmission status parameters of multiple telemetry and control links in real time, and determines whether the link status meets the first condition based on the transmission status parameters; wherein, the ground end uploads remote control uplink data to the flight control end by default through the first transmission method; While receiving telemetry data, the ground station continuously collects transmission status parameters for each telemetry and control link. These parameters include signal strength, packet loss rate, signal-to-noise ratio (SNR), transmission delay, and bit error rate (BER), such as the bit error rate. Data collection can be performed at fixed intervals, such as every 200 milliseconds. Signal strength can be obtained from the RSSI value of the wireless module. Transmission delay can be measured by the time difference between sending a probe packet and receiving a response. Packet loss rate can be obtained by calculating the ratio of the number of packets lost per second to the total number of packets sent. SNR is calculated as the ratio of signal power to noise power. BER is calculated by comparing the number of erroneous bits in the received data with the number of erroneous bits in the original data. During implementation, the collected signal strength, packet loss rate, SNR, transmission delay, and BER must be normalized to the range of 0 to 1.

[0025] Furthermore, determining the status of the multiple telemetry and control links based on the transmission status parameters includes: S31. Calculate the link quality score of the multi-channel telemetry and control link based on signal strength, data packet loss rate, signal-to-noise ratio, transmission delay, and data bit error rate, as shown in the following formula; Q = α×S + β×SNR + γ×(1 / T) + δ×(1-E) + ε×(1-L); Where Q is the link quality score, S is the signal strength, SNR is the signal-to-noise ratio, T is the transmission delay, E is the bit error rate, and L is the packet loss rate; α, β, γ, δ, and ε are weighting coefficients; the sum of the weighting coefficients α, β, γ, δ, and ε is 1, and typical values ​​can be adaptively adjusted according to the UAV flight scenario. For example, for high-speed mobile scenarios, focusing on transmission delay and signal strength, α=0.25, β=0.2, γ=0.3, δ=0.15, and ε=0.1 can be chosen. For urban obstructed scenarios, the weights of signal-to-noise ratio and packet loss rate need to be increased, and the values ​​of β and ε can be appropriately increased.

[0026] S32. Based on the link quality score, the multi-channel measurement and control link is divided into three states: normal, deteriorated, and faulty.

[0027] Based on the calculated link quality score Q, the ground station classifies the link status into three levels.

[0028] when When this occurs, it is considered a normal state; when ≤ Q< When this occurs, it is determined to be in a deteriorated state; When Q < When this occurs, it is determined to be a fault state.

[0029] in, The normal scoring threshold is 80 points. This is the fault threshold, such as 60 points. The normal scoring threshold and fault threshold can be adjusted based on actual flight test results; for example, in areas with complex electromagnetic environments, they can be appropriately lowered. For example, in environments with less communication interference, the efficiency can be improved accordingly. and The value of .

[0030] S4. When the first condition is met, the ground end switches to uploading remote control uplink data to the flight controller via the second transmission method, and continuously judges whether the link status meets the second condition based on the transmission status parameters. When the second condition is met, the ground end switches back to uploading remote control uplink data to the flight controller via the first transmission method.

[0031] The first condition is: the primary monitoring and control link is in a degraded or faulty state, and at least one backup monitoring and control link is in a normal state; the second condition is: the primary monitoring and control link is in a normal state, and the duration of the normal state exceeds a preset duration, wherein the criterion for judging the normal state is that the quality score is greater than or equal to the preset quality score threshold.

[0032] The first transmission method is: the ground end uses the primary telemetry and control link as the current communication link, and the ground end uploads remote control uplink data to the flight control terminal through the primary telemetry and control link; the second transmission method is: the ground end selects a backup telemetry and control link as the current communication link, and the ground end uploads remote control uplink data to the flight control terminal through the backup telemetry and control link.

[0033] When the primary telemetry and control link deteriorates or fails and at least one backup link is normal, the ground end switches to the second transmission mode, that is, selects a normal backup telemetry and control link as the current communication link to upload remote control uplink data; at the same time, the ground end continuously monitors the transmission status parameters of the primary telemetry and control link. When the link quality score of the primary telemetry and control link recovers to above the preset quality score threshold and continues for more than the preset time, the ground end switches back to the first transmission mode and reuses the primary telemetry and control link to upload remote control uplink data.

[0034] The flight control unit continuously transmits telemetry downlink data to the ground station synchronously via multiple telemetry and control links. The flight control unit does not need to participate in link status selection, and the ground station can obtain complete UAV status information at any time. The ground station independently completes the selection and switching of uplinks, reducing the computational load on the flight control computer, ensuring the real-time performance of core flight control tasks, and avoiding the problems of command duplication, data redundancy, and increased transmission latency caused by flight control unit involvement in switching in traditional solutions.

[0035] Furthermore, the ground end selects a backup telemetry and control link as the current communication link, including: When the number of backup monitoring and control links is 1, the backup monitoring and control link is selected as the current communication link; when the number of backup monitoring and control links is greater than 1, the multiple backup monitoring and control links are sorted according to the link quality score of each backup monitoring and control link. If only one backup telemetry and control link is configured in the system, the ground end will directly select the single backup link as the current communication link when a switch is required. If multiple backup telemetry and control links are configured in the system, they will be sorted in descending order of link quality score, that is, the backup telemetry and control link with the higher link quality score has the higher priority.

[0036] Based on the ranking results, the backup monitoring and control link with the highest link quality score is determined as the current communication link; when there are multiple backup monitoring and control links with the highest link quality score, one backup monitoring and control link is selected as the current communication link according to a preset priority rule. If multiple backup telemetry and control links with the highest link quality scores exist, the current communication link is determined according to a preset priority rule. The preset priority rule is as follows: Prioritize selecting the backup telemetry and control link with higher signal strength as the current communication link; if the signal strengths are the same, select the backup telemetry and control link with higher signal-to-noise ratio as the current communication link; if the signal-to-noise ratios are the same, select the backup telemetry and control link with lower data packet loss rate as the current communication link.

[0037] Under the same overall quality, the backup telemetry and control link with clearer signal, less noise, and less packet loss should be selected first.

[0038] Furthermore, the ground-based software architecture includes independent telemetry data receiving and display modules. The telemetry data receiving module simultaneously monitors all telemetry and control links, storing the telemetry data from each link into its respective buffer. The display module, a functional unit within the ground-based software, is responsible for parsing data and refreshing the interface. It records which link's data should be used for display, and this record remains consistent with the current telemetry and control link.

[0039] During normal operation, the data display module only reads data from the buffer corresponding to the current telemetry and control link and refreshes the display interface, without displaying data from other links. When a link switch is performed, the ground terminal first updates the record to reflect the new link, and the data display module automatically reads data from the buffer of the new link. Because the buffer of each telemetry and control link continuously receives data, the interface will not jump, flicker, or display incorrect information during the switch.

[0040] When the first condition or the second condition is met, the method further includes: S41. The ground terminal stores the remote control uplink data into the buffer queue according to the generation time sequence of the remote control uplink data; Each time the first or second condition is met, the ground station initiates a switch in transmission mode. During the switchover, because the link may be temporarily unavailable, all newly generated instructions are stored in a queue and not sent until the switchover is complete. The capacity of the buffer queue is pre-set according to flight safety requirements, for example, a queue length of 200 instructions. The buffer queue can be a first-in, first-out queue, storing data in the order of its generation time.

[0041] S42. After the transmission mode switch is completed, the ground terminal retransmits the remote control uplink data in the buffer queue to the flight control terminal through the current communication link.

[0042] Once the transmission mode switch is complete, meaning the ground end has successfully switched the current communication link to the backup telemetry and control link or the primary telemetry and control link, the ground end will then retransmit the remote control uplink data in the buffer queue to the flight control end through the current communication link.

[0043] Furthermore, S42 includes: S421. Generate a list of confirmation instructions based on the confirmation frame returned by the flight controller and the sequence number and check code carried in the remote control uplink data in the buffer queue; Each time the flight controller successfully receives a remote control uplink data, it returns an acknowledgment frame to the ground. The acknowledgment frame contains a unique sequence number of the received instruction. Before retransmitting, the ground collects the received acknowledgment frames, parses the sequence numbers, and combines them with the sequence number and cyclic redundancy check code carried by each instruction in the buffer queue to generate an acknowledgment instruction list. This list records which instruction numbers have been successfully received and verified by the flight controller.

[0044] S422. Based on the confirmed instruction list, filter the remote control uplink data that has been successfully received by the flight controller in the cache queue to obtain the set of instructions to be resent. The ground control unit iterates through all remote control uplink data in the buffer queue. For each instruction, it checks if its sequence number exists in the acknowledgment instruction list. If it exists, it means the flight controller has received and acknowledged the instruction, and the ground control unit removes it from the retransmission queue. If it does not exist, the instruction is retained and added to the set of instructions to be retransmitted.

[0045] S423. Calculate the retransmission rate based on the current transmission delay and data packet loss rate of the communication link; The retransmission rate refers to the number of commands or bytes that the ground terminal sends to the flight control terminal per second. To avoid congestion of the current communication link during the retransmission process, the retransmission rate needs to be adjusted according to the real-time status of the link, as shown in the following formula; ; in, Based on the base rate, such as 50 messages per second, This is the normal latency threshold, such as 100 milliseconds. For transmission delay, For data packet loss rate, This refers to the resend rate.

[0046] S424. According to the retransmission rate, the remote control uplink data in the set of instructions to be retransmitted is sent to the flight controller through the current communication link.

[0047] During implementation, the remote control uplink data in the resend command set is sorted according to the type of the remote control uplink data in the resend command set to obtain an ordered transmission queue; based on the order of the ordered transmission queue, the remote control uplink data is sent to the flight controller terminal one by one according to the resend rate; The command type is marked by the ground-based software based on the command content when generating the command, including safety-critical commands and general operation commands. Safety-critical commands include return to base, emergency landing, hovering, altitude limit, speed limit, etc., while general operation commands include attitude fine-tuning, heading fine-tuning, gimbal control, etc. All safety-critical commands are placed at the front of the queue, and general operation commands are placed at the back of the queue. Commands of the same type are arranged in the order of their original generation time.

[0048] After each remote control uplink data is sent, the system determines whether the transmission was successful based on the confirmation frame returned by the flight controller. If no confirmation frame is received, the system retransmits the data at the retransmission rate until a confirmation frame is received or the preset number of retransmissions is reached. If no confirmation frame is received after the preset number of retransmissions is reached, the ground terminal executes the preset safety protection strategy.

[0049] The transmission process can be implemented using a timer or a rate-controlled loop. For example, a timer can be set to send a command every 1 / R seconds. After each command is sent, a timeout timer is started to wait for an acknowledgment frame from the flight controller. If an acknowledgment frame is received within a preset time, the command is removed from the retransmission set, and the next command is sent. If no acknowledgment frame is received within the timeout period, the command is retransmitted. The ground control puts the command back into the queue and retransmits it at the current retransmission rate. The retransmission count counter is incremented by 1. If no acknowledgment is received after three retransmissions (a preset value), the link is considered to be unable to communicate normally, and a preset safety protection strategy is immediately executed, such as controlling the UAV to automatically return to the takeoff point, switching to autonomous hovering mode, or executing an emergency landing procedure. At the same time, the ground control reports a link abnormality alarm to alert the operators.

[0050] By retransmitting remote control upload data to the flight controller, it is ensured that no remote control commands generated during the switching period are lost or duplicated. By setting the retransmission rate, it is possible to avoid the current communication link from being blocked due to a large number of remote control commands being retransmitted in a short period of time. This ensures that the retransmission process will not interfere with the normal transmission of remote control commands and the reception of telemetry data, and ensures the transmission stability of the remote control uplink channel before and after the link switch.

[0051] Furthermore, after receiving each piece of remote control uplink data, the flight controller performs a validity check on each frame of data, including: The flight controller checks whether the received remote control uplink data matches the preset communication protocol and performs CRC verification on the received remote control uplink data. First, the frame header, frame trailer, and frame length are checked to ensure they match the preset communication protocol. The preset communication protocol is a pre-agreed data format between the flight controller and the ground control unit; for example, the frame header is 0x5A5A, the frame trailer is 0xA5A5, and the frame length field indicates the number of bytes in the data area. If the frame header and trailer do not match, or the frame length exceeds a reasonable range, the frame is deemed invalid. Then, the flight controller performs a CRC cyclic redundancy check on the data area, calculating the checksum using a preset CRC polynomial such as CRC-16-CCITT and comparing it with the checksum carried in the frame trailer. If a match is found, the data format is considered correct.

[0052] When the remote control uplink data matches the preset communication protocol and the CRC check passes, the flight controller determines that the received remote control uplink data format is correct and checks whether the control quantity in the remote control uplink data is within the preset threshold range. Once the format check and CRC check pass, the control values ​​in the remote control command are further verified to ensure they are within safe threshold ranges, preventing data mutations caused by link interference from leading to drone loss of control. For example, the preset range for throttle control values ​​is 0 to 1000. If a received command has a throttle value of 1200, it clearly exceeds the reasonable range and is deemed an invalid command. Similarly, the preset threshold for pitch angle commands is ±30 degrees. If a command requires 45 degrees, it is considered invalid.

[0053] If the data is within the threshold range, the flight controller determines that the remote control uplink data is valid and identifies the received remote control uplink data as a flight control command. If the control input is within a preset threshold range, the flight controller marks the uplink remote control data as valid, parses out the control commands such as increasing throttle or rolling to the left, and then sends the commands to the flight control module to drive actuators such as motors and control surfaces to perform the corresponding actions. Simultaneously, the flight controller returns an acknowledgment frame to the ground terminal.

[0054] If the remote control uplink data does not match the preset communication protocol, or the CRC check fails, or the remote control uplink data format is incorrect, or the control quantity in the remote control uplink data is not within the preset threshold range, the flight controller determines that the remote control uplink data is invalid and executes the preset safety protection strategy.

[0055] This invention provides a flight control link telemetry and control switching system, the system comprising: The configuration module is used to configure multiple telemetry and control links at the flight control end and the ground end. The multiple telemetry and control links include a primary telemetry and control link and at least one backup telemetry and control link. The downlink module is used to control the flight control terminal to synchronously transmit telemetry downlink data to the ground terminal through multiple telemetry and control links; The acquisition module is used to control the ground end to acquire the transmission status parameters of multiple telemetry and control links in real time, and to determine whether the link status meets the first condition based on the transmission status parameters; wherein, the ground end uploads remote control uplink data to the flight control end by default through the first transmission method; The switching module is used to switch the ground end to upload remote control uplink data to the flight controller via the second transmission method when the link status meets the first condition, and continuously judge whether the link status meets the second condition based on the transmission status parameters. When the second condition is met, the ground end switches back to uploading remote control uplink data to the flight controller via the first transmission method.

[0056] It is understandable that the modules recorded in this flight control link telemetry and control switching system are similar to those in the reference system. Figure 1 The steps in the described flight control link telemetry and control switching method correspond to each other. Therefore, the operations, characteristics, and beneficial effects described above for the flight control link telemetry and control switching method are also applicable to the flight control link telemetry and control switching system and its included modules, and will not be repeated here.

[0057] The following is for reference. Figure 3 The diagram illustrates a structural schematic of an electronic device 300 suitable for implementing some embodiments of the present invention. The electronic devices in some embodiments of the present invention may include, but are not limited to, mobile terminals such as mobile phones, laptops, digital broadcast receivers, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), in-vehicle terminals (e.g., in-vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computers. Figure 3 The terminal device shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments of the present invention.

[0058] like Figure 3 As shown, the electronic device 300 may include a processing unit (e.g., a central processing unit, a graphics processing unit, etc.) 301, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 302 or a program loaded from a storage device 308 into a random access memory (RAM) 303. The RAM 303 also stores various programs and data required for the operation of the electronic device 300. The processing unit 301, ROM 302, and RAM 303 are interconnected via a bus 304. An input / output (I / O) interface 305 is also connected to the bus 304.

[0059] Typically, the following devices can be connected to I / O interface 305: input devices 306 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 307 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 308 including, for example, magnetic tapes, hard disks, etc.; and communication devices 309. Communication device 309 allows electronic device 300 to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 3 An electronic device 300 with various devices is shown; however, it should be understood that it is not required to implement or possess all of the devices shown. More or fewer devices may be implemented or possessed alternatively. Figure 3 Each box shown can represent a device or multiple devices as needed.

[0060] Furthermore, the storage medium in the embodiments of this application stores program instructions capable of implementing all the above methods. These program instructions can be stored in the storage medium in the form of a software product, including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks, or terminal devices such as computers, servers, mobile phones, and tablets.

[0061] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for switching telemetry and control links in a flight control link, characterized in that, include: Multiple telemetry and control links are configured at the flight control end and the ground end, including a primary telemetry and control link and at least one backup telemetry and control link; The flight control unit synchronously transmits telemetry downlink data to the ground unit through multiple telemetry and control links; The ground terminal collects the transmission status parameters of multiple telemetry and control links in real time, and determines whether the link status meets the first condition based on the transmission status parameters; wherein, the ground terminal uploads remote control uplink data to the flight control terminal by default through the first transmission method; When the link status meets the first condition, the ground end switches to uploading remote control uplink data to the flight controller via the second transmission method, and continuously judges whether the link status meets the second condition based on the transmission status parameters. When the second condition is met, the ground end switches back to uploading remote control uplink data to the flight controller via the first transmission method.

2. The method according to claim 1, characterized in that, The status of the multi-channel telemetry and control links includes normal, deteriorated, and faulty; The first condition is: the status of the primary measurement and control link is degraded or faulty, and at least one backup measurement and control link is in normal status; The second condition is: the link status of the primary measurement and control link is normal, and the duration of the normal status exceeds the preset duration, wherein the criterion for judging the normal status is that the quality score is greater than or equal to the preset quality score threshold.

3. The method according to claim 1, characterized in that, The first transmission method is as follows: the ground end uses the primary telemetry and control link as the current communication link, and the ground end uploads remote control uplink data to the flight control terminal through the primary telemetry and control link; the second transmission method is as follows: the ground end selects a backup telemetry and control link as the current communication link, and the ground end uploads remote control uplink data to the flight control terminal through the backup telemetry and control link.

4. The method according to claim 2, characterized in that, When the first condition or the second condition is met, the method further includes: The ground terminal stores the remote control uplink data into a buffer queue according to the generation time sequence of the remote control uplink data; After the transmission mode switch is completed, the ground terminal retransmits the remote control uplink data in the buffer queue to the flight controller terminal through the current communication link.

5. The method according to claim 3, characterized in that, The ground end selects a backup telemetry and control link as the current communication link, including: When the number of backup telemetry and control links is 1, select that backup telemetry and control link as the current communication link; When the number of backup telemetry and control links is greater than 1, the backup telemetry and control links are sorted according to the link quality score of each backup telemetry and control link. Based on the ranking results, the backup monitoring and control link with the highest link quality score is determined as the current communication link; when there are multiple backup monitoring and control links with the highest link quality score, one backup monitoring and control link is selected as the current communication link according to a preset priority rule. The default priority rule is: Prioritize using the backup telemetry and control link with higher signal strength as the current communication link; If the signal strengths are the same, the backup telemetry and control link with a higher signal-to-noise ratio shall be selected as the current communication link. If the signal-to-noise ratio is the same, the backup telemetry and control link with the lower data packet loss rate is selected as the current communication link.

6. The method according to claim 4, characterized in that, Retransmitting the remote control uplink data in the buffer queue to the flight controller via the current communication link includes: A list of confirmation commands is generated based on the confirmation frames returned by the flight controller and the sequence number and checksum carried in the remote control uplink data in the buffer queue. Based on the confirmed instruction list, filter the remote control uplink data that has been successfully received by the flight controller in the cache queue to obtain the set of instructions to be resent. Calculate the retransmission rate based on the current transmission latency and data packet loss rate of the communication link; According to the retransmission rate, the remote control uplink data in the set of commands to be retransmitted is sent to the flight controller through the current communication link.

7. The method according to claim 6, characterized in that, According to the retransmission rate, sending the remote control uplink data in the set of commands to be retransmitted to the flight controller via the current communication link includes: Based on the type of remote control uplink data in the set of instructions to be resent, the remote control uplink data in the set of instructions to be resent is sorted to obtain an ordered transmission queue; Based on the order of the ordered transmission queue, remote control uplink data is sent to the flight controller terminal one by one according to the retransmission rate; After each remote control uplink data is sent, the system determines whether the transmission was successful based on the confirmation frame returned by the flight controller. If no confirmation frame is received, the system retransmits the data at the retransmission rate until a confirmation frame is received or the preset number of retransmissions is reached. If no confirmation frame is received after the preset number of retransmissions is reached, the ground terminal executes the preset safety protection strategy.

8. The method according to claim 1, characterized in that, The method further includes: The flight controller checks whether the received remote control uplink data matches the preset communication protocol and performs CRC verification on the received remote control uplink data. When the remote control uplink data matches the preset communication protocol and the CRC check passes, the flight controller determines that the received remote control uplink data format is correct and checks whether the control quantity in the remote control uplink data is within the preset threshold range. If the data is within the threshold range, the flight controller determines that the remote control uplink data is valid and identifies the received remote control uplink data as a flight control command. If the remote control uplink data does not match the preset communication protocol, or the CRC check fails, or the remote control uplink data format is incorrect, or the control quantity in the remote control uplink data is not within the preset threshold range, the flight controller determines that the remote control uplink data is invalid and executes the preset safety protection strategy.

9. The method according to claim 1, characterized in that, The transmission status parameters include signal strength, data packet loss rate, signal-to-noise ratio, transmission delay, and data bit error rate; The status determination of the multiple telemetry and control links based on the transmission status parameters includes: The link quality score of the multi-channel telemetry and control link is calculated based on signal strength, data packet loss rate, signal-to-noise ratio, transmission delay, and data bit error rate, as shown in the following formula; Q = α×S + β×SNR + γ×(1 / T) + δ×(1-E) + ε×(1-L); Where Q is the link quality score, S is the signal strength, SNR is the signal-to-noise ratio, T is the transmission delay, E is the bit error rate, L is the packet loss rate; α, β, γ, δ, and ε are weighting coefficients. Based on the link quality score, the multi-channel telemetry and control links are divided into three states: normal, deteriorated, and faulty.

10. A flight control link telemetry and control switching system, characterized in that, The system includes: The configuration module is used to configure multiple telemetry and control links at the flight control end and the ground end. The multiple telemetry and control links include a primary telemetry and control link and at least one backup telemetry and control link. The downlink module is used to control the flight control terminal to synchronously transmit telemetry downlink data to the ground terminal through multiple telemetry and control links; The acquisition module is used to control the ground end to acquire the transmission status parameters of multiple telemetry and control links in real time, and to determine whether the link status meets the first condition based on the transmission status parameters; wherein, the ground end uploads remote control uplink data to the flight control end by default through the first transmission method; The switching module is used to switch the ground end to upload remote control uplink data to the flight controller via the second transmission method when the link status meets the first condition, and continuously judge whether the link status meets the second condition based on the transmission status parameters. When the second condition is met, the ground end switches back to uploading remote control uplink data to the flight controller via the first transmission method.

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