Link latency testing method for unmanned aerial vehicle measurement and control system
By employing a latency testing method based on a real architecture in the UAV system, simulating data transmission flow and inserting time test points, the problems of inaccurate reflection of link latency characteristics and long testing time in traditional testing methods are solved, achieving efficient and accurate link latency testing.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- CHENGDU AIRCRAFT DESIGN INST OF AVIATION IND CORP OF CHINA
- Filing Date
- 2025-12-08
- Publication Date
- 2026-07-02
AI Technical Summary
Traditional methods for testing link delay in UAV telemetry and control systems lack systematicity, making it difficult to accurately reflect the delay characteristics of the link in the entire UAV system control loop, and the test configuration switching is time-consuming.
Adopting a real UAV system architecture, an integrated on-board and ground link latency testing method is designed. By simulating the data transmission flow in the UAV control environment through latency testing software, time test points of key links are inserted to calculate the latency and quality characteristics of the link system.
It enables accurate testing of link latency in UAV systems, reduces testing time, and improves the realism and time consistency of testing. It is applicable to various UAVs and control systems.
Smart Images
Figure CN2025140719_02072026_PF_FP_ABST
Abstract
Description
A method for testing link delay in UAV telemetry and control systems Technical Field
[0001] This invention belongs to the field of unmanned aerial vehicle (UAV) control technology and relates to a method for testing link delay in UAV telemetry and control systems. Background Technology
[0002] This invention belongs to the field of unmanned aerial vehicle (UAV) control technology, and relates to a method for testing link latency, specifically a method for testing link latency in a UAV telemetry and control system. As the channel for onboard ground information transmission in a UAV system, the performance of the telemetry and control system and the accuracy of management decisions directly affect the normal operation of the UAV system. Due to the use of wireless information transmission technology, communication latency is unavoidable. High latency can significantly impact the real-time control of the UAV and even threaten flight safety. Testing the latency caused by the link system and optimizing the system design based on the test results is essential.
[0003] Traditional link latency testing, limited by factors such as the division of labor within the UAV system, often involves separate simulated operational condition latency tests for ground control, the link itself, and the airborne system. While this testing can provide some feedback on the system's own latency characteristics, it lacks a comprehensive, systematic testing approach and cannot accurately reflect the link's latency characteristics within the entire UAV system's control loop. In the overall testing phase, the telemetry and control system's link latency is often separated from the airborne flight control and mission systems, testing only the uplink or downlink latency. This lacks a loop test connecting the uplink and downlink, requiring switching test configurations as needed, which is time-consuming when multiple configurations need to be tested. Summary of the Invention
[0004] Purpose of the invention
[0005] Based on the system architecture of a typical UAV, this invention proposes a link delay testing method for UAV telemetry and control systems. This method studies the data transmission characteristics of typical UAVs and draws on the characteristics of independent uplink and downlink delay testing in previous delay tests. It comprehensively designs an integrated link delay testing method for onboard and ground-based link equipment. Using the UAV system's own transmission protocol as the basis for loop test data protocol and the transmission path as the test channel, it can accurately reflect the characteristics of the link system, such as uplink and downlink delay and loop delay, as well as transmission quality, under the UAV control environment.
[0006] Technical solution
[0007] This invention integrates ground and onboard link equipment into a unified architecture design, realistically simulating the data flow of link data transmission under UAV control environment. By utilizing the effective data area in the UAV transmission protocol, time test points are inserted into each key link, ultimately calculating the latency and quality characteristics of each link in the link system.
[0008] A method for testing link latency in a UAV telemetry and control system is disclosed. This method employs a real UAV system architecture and additionally develops latency testing software. It consists of three parts: a real UAV control system, a real UAV link system, and the latency testing software. The real UAV control system utilizes a real UAV control console, control hardware, and system logic. The real UAV link system uses real UAV link ground and airborne data terminals and their associated hardware, software, and system logic. The latency testing software, simulating both control software and airborne system software, is deployed on the computer where the UAV control system's control software is deployed. This software is the core design element of this architecture. It simulates the UAV control software and airborne system software in the UAV control system, simulating the UAV control software sending latency test control data to the link system, simulating the airborne system software receiving remote control data from the airborne link terminal and sending telemetry data to the airborne link terminal, and simulating the UAV control software receiving telemetry data from the link system.
[0009] A method for testing link delay in an unmanned aerial vehicle (UAV) telemetry and control system includes the following steps:
[0010] Step 1: Start the UAV control system, link system ground and airborne equipment, start the latency test software of the present invention, but do not start the control software in the UAV control system;
[0011] Step 2: The delay test software simulates the control software to send delay test remote control data at regular intervals. The format of this remote control data fully conforms to the normal remote control protocol of the drone. The data contains the delay test frame number ID and the remote control sending time t0. The sending method is exactly the same as the way the drone's real system sends remote control data.
[0012] Step 3: The remote control encoding device encodes the delay test remote control data sent by the delay test software and sends it to the link ground terminal. The encoding method and process are exactly the same as those of the actual UAV system.
[0013] Step 4: The ground link terminal sends the UAV remote control frame data to the airborne link terminal via wired / wireless means. The transmission method is exactly the same as that of the actual UAV system.
[0014] Step 5: The airborne link terminal sends the UAV remote control frame data back to the latency test software via a wired connection. The sending method is exactly the same as the method by which the airborne link terminal sends data to the airborne system in the actual UAV system.
[0015] Step 6: The delay test software simulates the airborne system software receiving the drone remote control frame and records the remote control reception time t1;
[0016] Step 7: The delay test software simulates the airborne system software to organize telemetry data frames to the link airborne terminal. The telemetry data format fully conforms to the normal telemetry protocol of the UAV. The telemetry data frame contains the delay test remote control frame number ID, remote control transmission time t0, remote control reception time t1, and telemetry transmission time t2. The delay test remote control frame number ID and remote control transmission time t0 are extracted from the received remote control frame.
[0017] Step 8: The airborne terminal of the link receives telemetry data frames and sends them to the ground terminal of the link via wired / wireless means. The transmission method is exactly the same as that of the actual UAV system.
[0018] Step 9: The telemetry decoding device performs telemetry decoding on the UAV telemetry frames, and the decoding method is exactly the same as that of the actual UAV system;
[0019] Step 10: The link ground terminal sends the UAV telemetry frames to the latency test software in the same way as the link ground terminal sends them to the control software in the actual UAV system.
[0020] Step 11: The delay test software simulates the control software receiving the UAV telemetry frames and records the telemetry reception time t3;
[0021] Step 12: The latency testing software tests the uplink and downlink latency and loop latency of a single link data transmission based on a single test data point; it also performs data statistics and analysis based on multiple test data points.
[0022] Step 13: The latency testing software analyzes the quality of the link transmission based on the order, loss, and duplication of multiple test data.
[0023] Furthermore, the timer used in the delay test software in step 2 and the periodic characteristics of the remote control data transmission are exactly the same as those of the real system.
[0024] Furthermore, in step 7, the delay test software only simulates the transmission and reception logic of the airborne system receiving remote control data and sending telemetry data, and does not simulate its internal processing logic.
[0025] Furthermore, the timestamp processing in steps 2, 6, 7, and 11 is all performed by the delay testing software collecting the local time, so there is no issue with time synchronization across multiple devices.
[0026] The beneficial effects of this application are as follows:
[0027] Advantage 1: The test of this invention has strong realism. The test implementation of this method uses real equipment in the UAV system. The data flow, data format, data transmission and reception method and data processing logic in the link data transmission process of the UAV system are matched as closely as possible to the real UAV system, so the link latency of the UAV system can be tested relatively accurately.
[0028] Advantage 2: The present invention has good time consistency. As a time-related testing method, all time acquisition points are performed on the same device, and there is no situation of time synchronization of multiple devices. The time consistency is good and the time test is accurate.
[0029] Advantage 3: The invention has a relatively short testing time. It can simultaneously perform uplink delay testing, downlink delay testing, and loop delay testing. While testing link delay, it can also simultaneously perform statistical testing on the quality of data transmission and reception, which greatly saves testing time.
[0030] Advantage 4: This invention is a typical test method for UAV telemetry and control links, which can be widely used in various UAVs and related control systems. Attached Figure Description
[0031] Figure 1 shows a schematic diagram of a link delay test method for UAV telemetry and control systems.
[0032] Figure 2 is a data processing logic block diagram. Embodiments of the present invention
[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be described in more detail below. In the examples, the same or similar reference numerals denote the same or similar components or elements having the same or similar functions throughout. The described embodiments are some, but not all, of the embodiments of this invention. The embodiments described below with reference to reference are exemplary and intended to explain this invention, and should not be construed as limiting the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. The embodiments of this invention will be described in detail below.
[0034] An implementation method for testing link delay in a UAV telemetry and control system is as follows. Figure 2 shows a statistical logic diagram of the link delay testing method for a UAV telemetry and control system:
[0035] a) Start-up of ground and airborne equipment for the UAV control system and link system;
[0036] b) The delay test software simulates the characteristics of the control software and sends control and remote control frames according to the UAV protocol. The effective data area of the control frame includes the frame sequence number ID and the remote control sending time t0.
[0037] c) The ground link terminal encodes and outputs the control frame data and link control data according to the UAV protocol, and sends them to the airborne link terminal via wired / wireless means. The airborne link terminal then sends the UAV remote control frame to the latency test software.
[0038] d) The delay test software simulates the airborne system receiving remote control frames and records the remote control reception time t1;
[0039] e) The delay test software simulates the airborne system to record the telemetry transmission time t2 and transmits telemetry data frames. The telemetry data frames contain the frame sequence number ID, the remote control transmission time t0, the remote control reception time t1, and the telemetry transmission time t2.
[0040] f) The airborne terminal of the link receives telemetry data frames and sends them to the ground terminal of the link via wired / wireless means. The ground terminal of the link then sends the UAV telemetry frames to the delay test software.
[0041] g) The delay test software simulates the control software receiving telemetry frames and records the telemetry reception time t3;
[0042] h) The delay testing software calculates the link delay based on the single frame sequence number ID, remote control transmission time t0, remote control reception time t1, telemetry transmission time t2, and telemetry reception time t3:
[0043] 1) Uplink latency UP Link =Remote control reception time t1 - Remote control transmission time t0;
[0044] 2) Downlink Delay DN Link =Telemetry reception time t3 - Telemetry transmission time t2;
[0045] 3) Loop Delay ALL Link =Telemetry reception time t3 - Remote control transmission time t0.
[0046] a) The latency testing software runs for a period of time based on the system's timing characteristics, generally ensuring that the test data exceeds 100,000 frames, and the data is collected according to the following principles:
[0047] 1) Test Frame Count: The total number of test frames n recorded by the latency testing software;
[0048] 2) Error frames: Data frames whose synchronization header, frame type, or check fails, or data frames received by the receiver before the sender has sent the data (judged by frame sequence number), are counted in the error frame count Cerr.
[0049] 3) Re-frames: Duplicate received frames are counted in the re-frame count (Crep).
[0050] 4) Frame loss: Frames that are not received throughout the process are counted in the frame loss count Clost;
[0051] 5) Reverse-order frames: Frames that are received out of the order of transmission are counted in the reverse-order frame count Crev.
[0052] b) Calculate the average latency, frame drop rate, frame error rate, and reverse order rate link quality data based on the results of n tests:
[0053] 1) Average uplink latency =
[0054] 2) Average downlink latency =
[0055] 3) Average loop delay =
[0056] 4) Frame error rate = ;
[0057] 5) Frame rate = ;
[0058] 6) Frame drop rate = ;
[0059] 7) Reverse frame rate = .
[0060] c) Determine whether the link delay meets the basic requirements based on the test results. If it does not meet the requirements, retest after optimizing the link system until the requirements are met.
[0061] Furthermore, in step J), invalid data such as dropped frames, duplicate frames, and erroneous frames can be removed during the delay calculation process to increase statistical accuracy. Other statistical results such as root mean square can also be obtained based on the data.
[0062] d) The architecture consists of three parts: a real control system, a real link system, and latency testing software;
[0063] e) Delay testing software simulates control software + airborne system, deployed on the control system control software deployment computer, which is the core design point of this architecture;
[0064] f) The delay test software simulates the control software sending remote control data and simulates the airborne system receiving remote control data;
[0065] g) The remote control data sent by the delay test software is looped back to the delay test software via the link ground terminal and the link airborne equipment;
[0066] h) The delay test software simulates the airborne system sending telemetry data and the control software receiving telemetry data;
[0067] i) The telemetry data sent by the delay test software is routed back to the delay test software via the airborne equipment and ground terminal of the link;
[0068] j) The data protocol format of the remote control data and telemetry data sent by the delay test software is exactly the same as that of the real system;
[0069] k) The timer used in the delay test software and the periodic characteristics of the remote control data transmission are exactly the same as those of the real system;
[0070] l) The processing logic of remote control data and telemetry data in the link system is exactly the same as that of the real system;
[0071] m) The delay test software only simulates the transmission and reception characteristics of the airborne system in receiving remote control data and sending telemetry data, and does not simulate its internal processing logic;
[0072] n) The latency testing software tests the uplink and downlink latency and loop latency of a single link data transmission based on a single test data.
[0073] o) Delay testing software performs data statistics and analysis based on multiple test data points;
[0074] p) Delay testing software analyzes the quality of link transmission based on the order, loss, and duplication of multiple test data;
[0075] The timestamp processing for critical steps is all performed on the same device, so there is no issue of inconsistent time synchronization across multiple devices.
[0076] The latency test of this invention focuses on the latency of the link. The latency test software only simulates the transmission and reception cycle characteristics and data characteristics of the control software and airborne system, and cannot fully simulate the internal processing logic. The latency test results do not include the latency characteristics caused by the complex processing logic of the control software and airborne system.
[0077] Furthermore, unless otherwise defined, the technical or scientific terms used in this application description shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "upper," "lower," "left," "right," "center," "vertical," "horizontal," "inner," and "outer," etc., used in this application description to indicate relative direction or positional relationship are used only to indicate relative orientation or positional relationship, and do not imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. When the absolute position of the described object changes, its relative positional relationship may also change accordingly, and therefore should not be construed as a limitation on this application. The terms "first," "second," "third," and similar terms used in this application description are used only for descriptive purposes to distinguish different components, and should not be construed as indicating or implying relative importance. The terms "a," "one," or "the," etc., used in this application description should not be construed as an absolute limitation on quantity, but should be construed as indicating the existence of at least one. The terms "including," "comprising," etc., used in this application description mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, without excluding other elements or objects.
[0078] Furthermore, it should be noted that, unless otherwise explicitly specified and limited, terms such as “installation,” “connection,” and “linkage” used in the description of this application should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; or it can be a connection within two components. Those skilled in the art can understand its specific meaning in this application according to the specific circumstances.
[0079] The above description is merely a specific embodiment of the present invention and is not intended to limit the present invention. Within the spirit and principles of the present invention, any person skilled in the art may use the above-disclosed technical content to make changes or modifications to equivalent embodiments and apply them to other fields. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention, as well as any modifications, equivalent substitutions, improvements, etc., should be included within the protection scope of the present invention.
Claims
1. A method for testing link delay in an unmanned aerial vehicle (UAV) telemetry and control system, characterized in that, The system adopts a real UAV system architecture and is based on latency testing software. It consists of three parts: a real UAV control system, a real UAV link system, and latency testing software. The real UAV control system uses a real UAV operator's seat, control hardware, and system logic. The real UAV link system uses real UAV link ground and airborne data terminals and their associated hardware, software, and system logic. The latency testing software simulates both control software and airborne system software, and is deployed on the computer where the control software of the UAV control system is deployed. This software simulates the UAV control software and airborne system software in the UAV control system. It simulates the UAV control software sending latency test control data to the link system, the airborne system software receiving remote control data sent by the airborne link terminal and sending telemetry data to the airborne link terminal, and the UAV control software receiving telemetry data sent by the link system.
2. The method of claim 1, wherein, Includes the following steps: Step 1: Start the UAV control system, link system ground and airborne equipment, start the latency test software of the present invention, but do not start the control software in the UAV control system; Step 2: The delay test software simulates the control software to send delay test remote control data at regular intervals. The format of this remote control data fully conforms to the normal remote control protocol of the drone. The data contains the delay test frame number ID and the remote control sending time t0. The sending method is exactly the same as the way the drone's real system sends remote control data. Step 3: The remote control encoding device encodes the delay test remote control data sent by the delay test software and sends it to the link ground terminal. The encoding method and process are exactly the same as those of the actual UAV system. Step 4: The ground link terminal sends the UAV remote control frame data to the airborne link terminal via wired / wireless means. The transmission method is exactly the same as that of the actual UAV system. Step 5: The airborne link terminal sends the UAV remote control frame data back to the latency test software via a wired connection. The sending method is exactly the same as the method by which the airborne link terminal sends data to the airborne system in the actual UAV system. Step 6: The delay test software simulates the airborne system software receiving the drone remote control frame and records the remote control reception time t1; Step 7: The delay test software simulates the airborne system software to organize telemetry data frames to the link airborne terminal. The telemetry data format fully conforms to the normal telemetry protocol of the UAV. The telemetry data frame contains the delay test remote control frame number ID, remote control transmission time t0, remote control reception time t1, and telemetry transmission time t2. The delay test remote control frame number ID and remote control transmission time t0 are extracted from the received remote control frame. Step 8: The airborne terminal of the link receives telemetry data frames and sends them to the ground terminal of the link via wired / wireless means. The transmission method is exactly the same as that of the actual UAV system. Step 9: The telemetry decoding device performs telemetry decoding on the UAV telemetry frames, and the decoding method is exactly the same as that of the actual UAV system; Step 10: The link ground terminal sends the UAV telemetry frames to the latency test software in the same way as the link ground terminal sends them to the control software in the actual UAV system. Step 11: The delay test software simulates the control software receiving the UAV telemetry frames and records the telemetry reception time t3.
3. The method of claim 2, wherein, It also includes step 12: The latency testing software tests the uplink and downlink latency and loop latency of a single link data transmission based on a single test data; and performs data statistics and analysis based on multiple test data.
4. The method of claim 2, wherein, It also includes step 13: The latency testing software analyzes the quality of the link transmission based on the order, loss, and duplication of multiple test data.
5. The method as described in claim 2, characterized in that, In step 2, the delay test software uses the same periodic characteristics for transmitting remote control data as the real system.
6. The method as described in claim 2, characterized in that, In step 2, the delay test software uses a timer with the same periodic characteristics as the real system.
7. The method as described in claim 2, characterized in that, In step 7, the delay test software only simulates the transmission and reception logic of the airborne system receiving remote control data and sending telemetry data.
8. The method as described in claim 2, characterized in that, The timestamp processing in steps 2, 6, 7, and 11 is all performed by the delay testing software by collecting the local time.