Link delay test method for measurement and control system of unmanned aerial vehicle

Abstract

The invention belongs to the technical field of unmanned aerial vehicle control, and relates to an unmanned aerial vehicle measurement and control system link delay test method. According to the method, the data transmission characteristic of a typical unmanned aerial vehicle is studied, the characteristic of uplink and downlink independent test of a previous delay test is used for reference, the link delay test method for integration of onboard and ground chain equipment is comprehensively designed, a transmission protocol of an unmanned aerial vehicle system is used as a loop test data protocol basis, and a transmission path is used as a test channel; and the characteristics of uplink and downlink delay, loop delay and the like of the link system in an unmanned aerial vehicle control environment and the transmission quality can be accurately reflected.

Description

Technical Field

[0001] The invention belongs to the technical field of unmanned aerial vehicle control and relates to a link delay testing method for an unmanned aerial vehicle measurement and control system. Background Art

[0002] The present invention belongs to the field of drone control technology, and relates to a link delay test method, and specifically to a link delay test method for a drone measurement and control system. The measurement and control system is the channel for ground information transmission on the drone system. Its performance and the accuracy of management decisions will directly affect the normal operation of the drone system. Due to the use of wireless information transmission technology, communication delays are inevitable. High latency will have a great impact on the real-time control of the drone, and even threaten flight safety. It is very necessary to test the delay caused by the link system and optimize the system design according to the test situation.

[0003] Traditional link delay testing is limited by factors such as the division of labor in the UAV system. Ground control, link, and airborne systems often conduct simulated working condition delay tests separately. Although this test can provide feedback on certain system delay characteristics, it lacks overall and systematic testing methods and is difficult to accurately reflect the delay characteristics of the link in the entire UAV system control loop. During the overall testing phase, the link delay of the measurement and control system often separates the airborne flight control and mission system from the loop, and tests the uplink or downlink delay of the link separately. There is a lack of a loop test that connects the uplink and downlink. The test configuration needs to be switched on demand, and when multiple test configurations need to be tested, it takes a long time. Summary of the invention

[0004] Purpose of the Invention

[0005] Based on the system architecture of a typical UAV, the present invention proposes a link delay test method for a UAV measurement and control system. By studying the data transmission characteristics of a typical UAV and drawing on the characteristics of independent uplink and downlink tests in previous delay tests, the method comprehensively designs a link delay test method that integrates onboard and ground link equipment. The UAV system's own transmission protocol is used as the loop test data protocol basis, and the transmission path is used as the test channel. The method can accurately reflect the uplink and downlink delays, loop delays and other characteristics of the link system in a UAV control environment, as well as the transmission quality.

[0006] Technical Solution

[0007] The present invention integrates the architecture design of ground and onboard link equipment, realistically simulates the transmission data flow of link data in the UAV control environment, utilizes the effective data area in the UAV transmission protocol, inserts the time test points of each key link, and finally calculates the delay and quality characteristics of each link in the link system.

[0008] A method for testing link delay of an unmanned aerial vehicle measurement and control system adopts a real unmanned aerial vehicle system architecture and additionally develops delay testing software, which is composed of three parts: a real unmanned aerial vehicle control system, a real unmanned aerial vehicle link system, and delay testing software. The real unmanned aerial vehicle control system adopts a real unmanned aerial vehicle control seat, control hardware, and system logic; the real unmanned aerial vehicle link system adopts a real unmanned aerial vehicle link ground and airborne data terminal and its attached hardware and software and system logic; the delay testing software simulates the control software + airborne system software, and is deployed on the control software deployment computer of the unmanned aerial vehicle control system, which is the core design point in this architecture. The software simulates the unmanned aerial vehicle control software and airborne system software in the unmanned aerial vehicle control system, simulates the unmanned aerial vehicle control software to send delay test control data to the link system, simulates the airborne system software to receive the remote control data sent by the airborne link terminal and send the telemetry data to the airborne link terminal, and simulates the unmanned aerial vehicle control software to receive the telemetry data sent by the link system.

[0009] A method for testing link delay of an unmanned aerial vehicle measurement and control system comprises the following steps:

[0010] Step 1: The UAV control system, the ground and airborne equipment of the link system are started, the delay test software of the present invention is started, and the control software in the UAV control system is not started;

[0011] Step 2: The delay test software simulates the control software to periodically send out delay test remote control data. The remote control data format is completely consistent with the normal remote control protocol of the drone. The data contains the delay test frame ID and the remote control sending time t0. The sending method is exactly the same as the way the real drone 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 real drone system;

[0013] Step 4: The link ground terminal sends the drone remote control frame data to the link airborne terminal via wired / wireless means. The transmission method is exactly the same as that of the real drone system.

[0014] Step 5: The link airborne terminal sends the drone remote control frame data back to the delay test software via wired mode. The sending method is exactly the same as the way the link airborne terminal sends the data to the airborne system in the real drone system.

[0015] Step 6: The delay test software simulates the airborne system software to receive 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 the telemetry data frame to the link airborne terminal. The telemetry data format is completely consistent with the normal telemetry protocol of the UAV. The telemetry data frame contains the delay test remote control frame sequence number ID, remote control sending time t0, remote control receiving time t1, and telemetry sending time t2. The delay test remote control frame sequence number ID and remote control sending time t0 are extracted from the received remote control frame;

[0017] Step 8: The link airborne terminal receives the telemetry data frame and sends it to the link ground terminal via wired / wireless means. The transmission method is exactly the same as the real system of the drone.

[0018] Step 9: The telemetry decoding device performs telemetry decoding on the drone telemetry frame, and the decoding method is exactly the same as the real drone system;

[0019] Step 10: The link ground terminal sends the drone telemetry frame to the delay test software in exactly the same way as the link ground terminal sends the frame to the control software in the real drone system.

[0020] Step 11: The delay test software simulates the control software receiving the UAV telemetry frame and records the telemetry reception time t3;

[0021] Step 12: The delay test software tests the uplink and downlink delays and loop delays of a single link data transmission based on a single test data; and performs data statistics and analysis based on multiple test data tests;

[0022] Step 13: The delay test software analyzes the quality of link transmission based on the sequence, loss, and duplication of multiple test data;

[0023] Furthermore, the timer used by the delay test software in step 2 and the periodic characteristics of sending remote control data are exactly the same as those of the real system;

[0024] Furthermore, the delay test software in step 7 only simulates the transceiver 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 performed by the delay test software collecting the local time, and there is no problem of multi-device time synchronization.

[0026] The beneficial effects of this application are:

[0027] Advantage 1: The test authenticity of the present invention is strong. The test implementation of the method uses real equipment in the UAV system. The data flow, data format, data transmission and reception method, and data processing logic in the UAV system link data transmission process are matched with the real UAV system as much as possible, which can relatively accurately test the link delay in the UAV system.

[0028] Advantage 2: The present invention has good time consistency. As a time-related test method, all time collection points of the method are performed on the same device, and there is no multi-device time synchronization. The time consistency is good and the time test is accurate.

[0029] Advantage 3: The test time of the present invention is relatively short. The present invention can simultaneously perform uplink delay test, downlink delay test, and loop delay test. While testing the link delay, the quality of data transmission and reception can also be statistically tested synchronously, which greatly saves test time.

[0030] Advantage 4: The present invention is a typical UAV measurement and control link testing method, which can be promoted and used in various UAVs and related control systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A flow chart of the link delay test method for UAV measurement and control system is given; Figure 2 This is a logic block diagram for data processing. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the implementation of the present invention clearer, the technical scheme in the embodiment of the present invention will be described in more detail in combination with the embodiment of the present invention. In the example, the same or similar reference numerals throughout represent the same or similar originals or elements with the same or similar functions. The described embodiments are part of the embodiments of the present invention, not all of them. The embodiments described below by reference are exemplary and intended to be used to explain the present invention, and should not be construed as limitations on the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present invention. The following is a detailed description in combination with the embodiments of the present invention.

[0033] An implementation method of a link delay test method for a UAV measurement and control system is as follows: Figure 2 A statistical logic diagram of the link delay test method for UAV measurement and control system is given:

[0034] a) UAV control system, link system ground and airborne equipment start-up;

[0035] b) The delay test software simulates the characteristics of the control software and sends out a control remote control frame according to the drone protocol. The effective data area of ​​the control frame contains the frame sequence number ID and the remote control sending time t0;

[0036] c) The link ground terminal encodes and outputs the control frame data and link control data according to the UAV protocol, and sends them to the link airborne terminal via wired / wireless means. The link airborne terminal sends the UAV remote control frame to the delay test software;

[0037] d) The delay test software simulates the airborne system receiving the remote control frame and records the remote control reception time t1;

[0038] e) The delay test software simulates the airborne system to record the telemetry sending time t2 and send out a telemetry data frame, which contains the frame sequence number ID, remote control sending time t0, remote control receiving time t1, and telemetry sending time t2;

[0039] f) The link airborne terminal receives the telemetry data frame and sends it to the link ground terminal via wired / wireless means. The link ground terminal sends the UAV telemetry frame to the delay test software;

[0040] g) The delay test software simulates the control software to receive the telemetry frame and records the telemetry reception time t3;

[0041] h) The delay test software calculates the link delay based on the single frame sequence number ID, remote control sending time t0, remote control receiving time t1, telemetry sending time t2, and telemetry receiving time t3:

[0042] 1) Uplink delay UP Link = remote control receiving time t1 - remote control sending time t0;

[0043] 2) Downlink delay DN Link =telemetry receiving time t3-telemetry sending time t2;

[0044] 3) Loop delay ALL Link =telemetry receiving time t3-remote control sending time t0.

[0045] i) The delay test software runs for a period of time according to the system time characteristics, generally ensuring that the test data is above 100,000 frames, and the statistics are calculated according to the following principles:

[0046] 1) Test frame number: the total number of test frames n recorded by the delay test software;

[0047] 2) Error frame: If the received data frame synchronization header, frame type, or check fails, or the sender has not sent the data but the receiver has received it (judged by the frame sequence number), it will be counted in the error frame count Cerr;

[0048] 3) Repeated frames: Repeatedly received frames are counted into the repeated frame count Crep;

[0049] 4) Frame loss: Frames that are not received during the entire process are counted into the frame loss count Clost;

[0050] 5) Reverse sequence frame: The frames received in a sequence other than the sending sequence are counted in the reverse sequence frame count Crev;

[0051] j) Calculate the average delay time, frame loss rate, frame error rate, and reverse frame rate link quality data based on n test results:

[0052] 1) Where i is defined as the i-th record;

[0053] 2) Where i is defined as the i-th record;

[0054] 3) Where i is defined as the i-th record;

[0055] 4)

[0056] 5)

[0057] 6)

[0058] 7)

[0059] k) Determine whether the link delay meets the basic requirements based on the test results. If not, retest after link system optimization until it meets the requirements;

[0060] Furthermore, in the step J), invalid data such as lost frames, duplicate frames, and error frames can be eliminated during the delay calculation process to increase statistical accuracy, and other statistical results such as the root mean square can be obtained based on the data.

[0061] a) The architecture consists of three parts: real control system, real link system, and delay test software;

[0062] b) The delay test software simulates the control software + airborne system and is deployed on the control system control software deployment computer, which is the core design point in this architecture;

[0063] c) The delay test software simulates the control software sending remote control data and simulates the airborne system receiving remote control data;

[0064] d) The remote control data sent by the delay test software is looped back to the delay test software via the link ground terminal and link airborne equipment;

[0065] e) The delay test software simulates the airborne system sending telemetry data and simulates the control software receiving telemetry data;

[0066] f) The telemetry data sent by the delay test software is looped back to the delay test software via the link airborne equipment and the link ground terminal;

[0067] g) 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;

[0068] h) The timer used by the delay test software and the periodic characteristics of sending remote control data are exactly the same as those of the real system;

[0069] i) The link system's processing logic for remote control data and telemetry data is exactly the same as that of the real system;

[0070] j) The delay test software only simulates the receiving and sending characteristics of the airborne system for receiving remote control data and sending telemetry data, and does not simulate its internal processing logic;

[0071] k) The delay test software tests the uplink and downlink delays and loop delays of a single link data transmission based on a single test data;

[0072] l) The delay test software performs data statistics and analysis based on multiple test data tests;

[0073] m) The delay test software analyzes the quality of link transmission based on the sequence, loss, and duplication of multiple test data;

[0074] The timestamp processing of key links is all performed on the same device, and there is no problem of inconsistent time systems among multiple devices.

[0075] The delay focus of the architecture test of the present invention is on the link delay. The delay test software only simulates the transmit and receive cycle characteristics and data characteristics of the control software and the airborne system, and cannot completely simulate the internal processing logic. The delay results of its test do not include the delay characteristics caused by the complex processing logic of the control software and the airborne system.

[0076] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of this application shall be the common meanings understood by the general technicians in the field to which this application belongs. The words "upper", "lower", "left", "right", "center", "vertical", "horizontal", "inside", "outside" and other words indicating orientation used in the description of this application are only used to indicate the relative direction or positional relationship, and do not imply that the device or element must have a specific orientation, 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, so it cannot be understood as a limitation on this application. The "first", "second", "third" and similar terms used in the description of this application are only used for descriptive purposes to distinguish different components, and cannot be understood as indicating or implying relative importance. The similar words "one", "one" or "the" used in the description of this application should not be understood as an absolute limitation on quantity, but should be understood as the existence of at least one. The similar words "including" or "comprising" used in the description of this application mean that the elements or objects appearing in front of the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0077] In addition, it should be noted that, unless otherwise clearly specified and limited, the words "installed", "connected", "connected" and similar terms used in the description of this application should be understood in a broad sense. For example, the 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, an indirect connection through an intermediate medium, or the internal connection of two components. Technical personnel in the field can understand their specific meanings in this application according to the specific circumstances.

[0078] The above description is only a specific implementation mode of the present invention and is not intended to limit the present invention. Within the spirit and principle of the present invention, any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes and apply it to other fields. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the technical solution content of the present invention, any modification, equivalent replacement, improvement, etc. made should be included in the protection scope of the present invention.

Claims

1. A method for testing link delay of an unmanned aerial vehicle measurement and control system, characterized in that: It adopts a real UAV system architecture and is based on delay test software. It consists of three parts: a real UAV control system, a real UAV link system, and a delay test software. The real UAV control system adopts a real UAV control seat, control hardware and system logic; the real UAV link system adopts a real UAV link ground and airborne data terminal and its affiliated hardware and software and system logic; the delay test software simulates the control software + airborne system software, and is deployed on the UAV control system control software deployment computer. The software simulates the UAV control software and airborne system software in the UAV control system, simulates the UAV control software sending delay test control data to the link system, simulates the airborne system software receiving the remote control data sent by the airborne link terminal and sending telemetry data to the airborne link terminal, and simulates the UAV control software receiving the telemetry data sent by the link system.

2. The method according to claim 1, characterized in that The steps include: Step 1: The UAV control system, the ground and airborne equipment of the link system are started, the delay test software of the present invention is started, and the control software in the UAV control system is not started; Step 2: The delay test software simulates the control software to periodically send out delay test remote control data. The remote control data format is completely consistent with the normal remote control protocol of the drone. The data contains the delay test frame ID and the remote control sending time t0. The sending method is exactly the same as the way the real drone 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 real drone system; Step 4: The link ground terminal sends the drone remote control frame data to the link airborne terminal via wired / wireless means. The transmission method is exactly the same as that of the real drone system. Step 5: The link airborne terminal sends the drone remote control frame data back to the delay test software via wired mode. The sending method is exactly the same as the way the link airborne terminal sends the data to the airborne system in the real drone system. Step 6: The delay test software simulates the airborne system software to receive 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 the telemetry data frame to the link airborne terminal. The telemetry data format is completely consistent with the normal telemetry protocol of the UAV. The telemetry data frame contains the delay test remote control frame sequence number ID, remote control sending time t0, remote control receiving time t1, and telemetry sending time t2. The delay test remote control frame sequence number ID and remote control sending time t0 are extracted from the received remote control frame; Step 8: The link airborne terminal receives the telemetry data frame and sends it to the link ground terminal via wired / wireless means. The transmission method is exactly the same as the real system of the drone. Step 9: The telemetry decoding device performs telemetry decoding on the drone telemetry frame, and the decoding method is exactly the same as the real drone system; Step 10: The link ground terminal sends the drone telemetry frame to the delay test software in exactly the same way as the link ground terminal sends the frame to the control software in the real drone system. Step 11: The delay test software simulates the control software receiving the UAV telemetry frame and records the telemetry reception time t3.

3. The method according to claim 2, characterized in that The method also includes step 12: the delay test software tests the uplink and downlink delays and loop delays of a single link data transmission according to a single test data; and performs data statistics and analysis according to multiple test data tests.

4. The method according to claim 2, characterized in that The method also includes step 13: the delay test software analyzes the quality of link transmission according to the sequence, loss and repetition of multiple test data.

5. The method according to claim 2, characterized in that The periodic characteristics of the remote control data sent by the delay test software in step 2 are exactly the same as those of the real system.

6. The method according to claim 2, characterized in that The periodic characteristics of the timer used by the delay test software in step 2 are exactly the same as those of the real system.

7. The method according to claim 2, characterized in that The delay test software in step 7 only simulates the transceiver logic of the airborne system receiving remote control data and sending telemetry data.

8. The method according to claim 2, characterized in that The timestamp processing in steps 2, 6, 7, and 11 is performed by the delay test software collecting the local time.

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