Bus communication system and method based on composite wing unmanned aerial vehicle power system

Abstract

The application provides a bus communication system and method based on a compound wing unmanned aerial vehicle power system, which comprises a bus repeater, a standard bus interface module, a double bus communication protocol module and a bus topology structure module; the bus repeater comprises a data transceiving module, a data processing module and a data storage module; the data transceiving module comprises a non-isolation unit and an isolation unit; the non-isolation unit is connected with a flight control navigation system; the isolation unit is connected with the standard bus interface module; the double bus communication protocol module comprises a bus competition processing protocol unit, a data analysis and distribution protocol unit and a fault processing protocol unit; the bus topology structure module adopts a tree topology and comprises a main bus and a plurality of branch buses; and the application can realize safe and efficient transmission of data between the power system and the flight control navigation system, improve the anti-interference ability, expandability and fault tolerance of the system.

Description

Technical Field

[0001] This invention relates to the field of communication technology for unmanned aerial vehicle (UAV) power systems, and in particular to a bus communication system and method based on a compound wing UAV power system. Background Technology

[0002] The vertical takeoff and landing (VTOL) propulsion system of large VTOL compound wing UAVs is characterized by high voltage, high power, and high electromagnetic radiation. During signal transmission, voltage fluctuations and high current fluctuations can easily generate strong electromagnetic interference. At the same time, the propulsion system of this type of UAV has extremely high requirements for the transmission speed, control frequency, information transmission volume, and accuracy of control and feedback signals.

[0003] In existing technologies, the power systems of large vertical take-off and landing (VTOL) UAVs mostly adopt point-to-point communication methods such as PWM and TTL, which have obvious limitations: First, they have poor scalability, requiring extensive rewiring when adding or replacing equipment, making the operation cumbersome; second, they have weak anti-interference capabilities, making it difficult to resist the strong electromagnetic interference generated by the power system itself, which easily leads to signal distortion; third, they have poor maintainability, with complex point-to-point wiring and difficult troubleshooting; fourth, they have low fault tolerance, with a single communication link failure easily causing the entire power system to fail, seriously affecting the flight safety of the UAV.

[0004] Therefore, it is necessary to study a bus communication system and method based on the power system of a compound wing UAV to address the shortcomings of existing technologies and solve or mitigate one or more of the above-mentioned problems. Summary of the Invention

[0005] In view of this, the present invention provides a bus communication system and method based on the power system of a compound wing UAV, which can realize the secure and efficient transmission of data between the power system and the flight control and navigation system, while improving the system's anti-interference capability, scalability and fault tolerance capability.

[0006] On one hand, the present invention provides a bus communication system based on a compound wing UAV power system, the bus communication system based on a compound wing UAV power system includes: a bus repeater, a standard bus interface module, a dual bus communication protocol module and a bus topology module; The bus repeater includes a data transceiver module, a data processing module, and a data storage module. The data transceiver module includes a non-isolated unit and an isolated unit. The non-isolated unit is connected to the flight control and navigation system of the UAV power system, and the isolated unit is connected to the standard bus interface module. The data transceiver module is connected to the data storage module through the data processing module. The standard bus interface module includes a CAN bus interface unit and an RS485 bus interface unit; The dual-bus communication protocol module includes a bus contention processing protocol unit, a data parsing and distribution protocol unit, and a fault handling protocol unit. The bus contention processing protocol unit, the data parsing and distribution protocol unit, and the fault handling protocol unit are all connected to both the CAN bus interface unit and the RS485 bus interface unit. The bus topology module adopts a tree topology, including a trunk bus and several branch buses, and the several branch buses are connected to the bus repeater through the trunk bus.

[0007] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the bus repeater is installed in an electromagnetically shielded cabin, the bus cable is a shielded twisted pair with a characteristic impedance of 120Ω, the isolation unit of the data transceiver module adopts an electrical isolation design, and the data storage module is configured with a storage medium of ≥16GB for recording flight control command data, power system feedback data, and bus communication status data.

[0008] In addition to the aspects and any possible implementations described above, an implementation is further provided in which the CAN bus interface unit supports baud rates of 250kbps, 500kbps, and 1Mbps, and the RS485 bus interface unit supports baud rates of 9600bps to 115200bps. Both interface units support device ID configuration and seamless integration.

[0009] In addition to the aspects described above and any possible implementation, a further implementation is provided in which the bus contention processing protocol unit realizes automatic switching between the master bus and the backup bus by detecting the bus signal quality, with a switching response time ≤50ms, and the bus signal quality including signal-to-noise ratio and bit error rate.

[0010] In addition to the aspects described above and any possible implementation, a further implementation is provided in which the data parsing and distribution protocol unit supports 0 to 1024 configurable device IDs, each ID corresponding to 8 bytes of transmitted data, and the bus load rate is controlled below 50%.

[0011] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the fault handling protocol unit monitors bus data in real time, and when a bus of a device fails, it switches to another normal bus of that device, with a fault detection cycle of ≤5ms.

[0012] In addition to the aspects described above and any possible implementation, an implementation is further provided in which the trunk bus length of the tree topology is ≤10m, the branch bus length is ≤5m, the long branch line length is >3m and is configured with matching resistors or repeaters.

[0013] In addition to the aspects described above and any possible implementation, a further implementation is provided in which the data processing module employs a microcontroller with a main frequency ≥480MHz, supporting synchronous parsing and format conversion of CAN bus and RS485 bus data.

[0014] In addition to the aspects described above and any possible implementation, a further implementation is provided in which the CAN bus interface unit supports communication of up to 110 nodes and the RS485 bus interface unit supports communication of up to 32 nodes, and has error detection and fault tolerance functions.

[0015] In accordance with the aspects and any possible implementations described above, a bus communication method based on a compound wing UAV power system is further provided. The bus communication method based on the compound wing UAV power system is implemented through the bus communication system based on the compound wing UAV power system. The bus communication method based on the compound wing UAV power system is used to achieve secure data transmission between the compound wing UAV power system and the flight control and navigation system.

[0016] Compared with the prior art, the present invention can achieve the following technical effects: 1. This invention employs a bus transceiver: the data transceiver module realizes the separation and isolated transmission of flight control and power bus data, improving security; the data processing module flexibly converts data formats, with strong adaptability; the data storage module comprehensively records data, facilitating later analysis and troubleshooting, and improving system reliability and maintenance efficiency; 2. This invention uses a standard bus interface: Using a standard interface enables efficient and reliable communication between different devices, improving the overall performance and stability of the system; it also facilitates device interoperability and scalability, reducing system integration and maintenance costs; the heterogeneous dual-bus system significantly enhances the anti-interference capability of the power system in various environments, thereby greatly enhancing the stability and reliability of the entire power communication system. 3. The dual-bus communication protocol of this invention: By designing a dual-bus communication protocol and a bus contention protocol, the coordination between heterogeneous buses is significantly improved, ensuring the smoothness of the switching process between different buses. Simultaneously, by optimizing the bus data parsing and distribution protocol, not only is high-efficiency data transmission achieved, but also a balanced distribution of bus load is promoted, significantly reducing the overall bus load rate and instantaneous load peaks. Furthermore, the design of the bus fault handling protocol endows the bus system with a certain degree of self-healing capability and fault isolation characteristics. This series of design measures not only improves the system's real-time response capability and enhances its stability and reliability, but also effectively improves data transmission efficiency, reduces bus burden, reduces data conflicts and transmission delays, and achieves optimal resource utilization.

[0017] 4. The tree-like design of the bus topology in this invention exhibits significant advantages and positive effects. Its clear and hierarchical structure makes the network layout more orderly, facilitating subsequent expansion and maintenance. The introduction of branch structures effectively shortens wiring distances, reduces material costs, and improves signal transmission efficiency. Furthermore, the tree-like topology makes node expansion simple and easy, and path finding is faster and more convenient. This design not only reduces signal interference but also improves system communication efficiency, ensuring overall operational stability and reliability, and providing strong support for building an efficient and secure network system.

[0018] 5. The large vertical takeoff and landing (VTOL) compound wing UAV power system of this invention adopts a bus transceiver, standard bus interface, dual-bus communication protocol, and tree topology design to achieve secure and efficient transmission of power data; data separation and isolation improve security, while flexible data processing and storage enhance system reliability and maintenance efficiency; the standard interface and dual-bus system enhance device interoperability, scalability, and anti-interference capabilities; the optimized communication protocol reduces bus load, lowers data conflicts and latency, and achieves resource optimization; the tree topology ensures an orderly network layout, facilitates expansion and maintenance, and ensures system communication efficiency and stability, providing a practical and effective solution for the efficient and safe operation of UAV power communication systems.

[0019] Of course, any product implementing this invention does not necessarily need to achieve all of the technical effects described above at the same time. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a system architecture diagram of a bus repeater provided in one embodiment of the present invention; Figure 2 This is a system architecture diagram of a dual-bus communication protocol provided in one embodiment of the present invention; Figure 3 This is a system structure diagram of a bus topology provided in one embodiment of the present invention; Figure 4 This is a flowchart of a bus communication method based on a compound wing unmanned aerial vehicle (UAV) power system, provided by an embodiment of the present invention. Detailed Implementation

[0022] To better understand the technical solution of the present invention, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0023] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0024] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0025] This invention provides a bus communication system based on a compound-wing unmanned aerial vehicle (UAV) power system, comprising: a bus repeater, a standard bus interface module, a dual-bus communication protocol module, and a bus topology module; The bus repeater includes a data transceiver module, a data processing module, and a data storage module. The data transceiver module includes a non-isolated unit and an isolated unit. The non-isolated unit is connected to the flight control and navigation system of the UAV power system, and the isolated unit is connected to the standard bus interface module. The data transceiver module is connected to the data storage module through the data processing module. The standard bus interface module includes a CAN bus interface unit and an RS485 bus interface unit; The dual-bus communication protocol module includes a bus contention processing protocol unit, a data parsing and distribution protocol unit, and a fault handling protocol unit. The bus contention processing protocol unit, the data parsing and distribution protocol unit, and the fault handling protocol unit are all connected to both the CAN bus interface unit and the RS485 bus interface unit. The bus topology module adopts a tree topology, including a trunk bus and several branch buses, and the several branch buses are connected to the bus repeater through the trunk bus.

[0026] This invention also provides a bus communication method based on a compound-wing UAV power system. The following description will detail the overall process and specific steps to ensure the feasibility and logical consistency of the technical solution. Figure 4As shown, the overall process of the power system bus communication method provided in this embodiment of the invention is first introduced. It includes the following steps: S1: Acquiring flight control commands and converting them into power control commands via a bus repeater, wherein the bus repeater adopts an isolated communication mode to enhance anti-interference capability; S2: Using standard bus interfaces including a CAN interface and an RS485 interface, supporting multi-device integration and expansion through modification of device IDs; S3: Applying a dual-bus communication protocol to ensure that the CAN interface and the RS485 interface independently control the power system, realizing bus contention processing, data parsing and distribution, and fault handling to achieve synchronization and switching; S4: Configuring the bus topology as a tree topology, shortening branch lengths, and adding impedance matching components to reduce signal reflection and improve reliability. This method mainly targets the power system control requirements of compound-wing UAVs in various flight modes, achieving efficient transmission of flight control commands and precise response of power equipment through bus communication technology. The overall process includes steps such as acquiring flight control commands and converting them into power control commands, using standard bus interfaces to support multi-device integration, applying a dual-bus communication protocol to achieve independent control, and configuring a tree topology to improve communication reliability. Each step will be described in detail below with reference to specific implementation methods.

[0027] Step S1 involves acquiring flight control commands and converting them into power control commands via a bus repeater. The bus repeater employs an isolated communication mode to enhance anti-interference capabilities. Specifically, during flight, the flight control system generates control commands in real time, including requirements for the power system's speed and thrust distribution. These commands are transmitted to the bus repeater via a communication interface. The bus repeater acts as an intermediate bridge, parsing the flight control commands and converting them into control signals recognizable by the power system. In this process, the isolated communication mode is a key design feature. It primarily uses electrical isolation technology to separate the data transmission channels between the flight control system and the power system, preventing electromagnetic interference or voltage fluctuations from affecting the flight control system. For example, during high-altitude flight, the compound-wing UAV may be subject to strong external electromagnetic interference; the isolated communication mode effectively shields against this interference, ensuring the stability of command transmission.

[0028] Furthermore, the implementation of isolated communication mode relies on the internal hardware design and software protocol of the bus repeater. In hardware, the bus repeater typically integrates opto-isolators or transformer isolation circuits to physically isolate the signals at the input and output ends. In software, the bus repeater verifies the received flight control commands, ensuring data integrity before forwarding them to the power system. This design is particularly important when compound-wing UAVs perform complex tasks, such as flying in urban environments where there may be significant radio signal interference. Isolated communication mode can significantly improve the system's anti-interference capability and ensure flight safety.

[0029] In step S11, the bus repeater acquires flight control commands and separates them into non-isolated flight control data and isolated power bus data. In one embodiment, the bus repeater first receives command data sent by the flight control system through an input interface. This data is typically transmitted in digital signal form and includes information such as flight attitude adjustment and power distribution. After receiving the data, the bus repeater divides it into two parts: one part is non-isolated flight control data, used for internal processing and recording; the other part is isolated power bus data, transmitted to the power system through an isolation circuit. This separation design ensures signal independence between the flight control system and the power system, preventing high-voltage or high-frequency interference from the power system from being fed back to the flight control system. For example, when a compound-wing UAV performs vertical takeoff and landing missions, the high-frequency current of the motors may cause interference; separating the data can effectively protect the stable operation of the flight control system.

[0030] It should be noted that the data separation process also includes preliminary parsing of flight control commands. The bus repeater identifies key fields in the commands, such as target device addresses and control parameters, according to a preset communication protocol, and categorizes these fields into non-isolated data and isolated data. Non-isolated data is typically stored in the repeater's local cache for subsequent analysis or troubleshooting, while isolated data is transmitted directly to the power unit through an isolated channel. This separation method reduces data transmission latency in actual flight, ensuring the power system can respond quickly to flight control commands.

[0031] Step S12 involves receiving flight control commands and forwarding power system data via the data transceiver module, while simultaneously isolating and transmitting flight control commands and power system data through RS485 and CAN interfaces. Specifically, the data transceiver module is a core component of the bus repeater, responsible for receiving commands and forwarding data. At the receiving end, the data transceiver module acquires command signals through the flight control system's output interface and decodes them. At the forwarding end, the data transceiver module sends data to the power system via the RS485 or CAN interface according to the communication requirements of the target device. Both the RS485 and CAN interfaces employ isolated transmission methods during this process, such as using isolation chips or isolation transformers to achieve electrical signal isolation, ensuring that data transmission is not subject to external interference.

[0032] For example, when a compound-wing UAV performs long-distance cruise missions, the power system may be distributed in different locations on the wings and fuselage, resulting in long data transmission distances. The long-distance transmission capability of the RS485 interface can meet the requirements, and its isolation design can effectively resist electromagnetic interference along the route. The CAN interface, on the other hand, is more suitable for short-distance, high-real-time transmission. For example, in vertical takeoff and landing mode, the CAN interface can quickly transmit motor speed adjustment commands, ensuring the immediate response of the power system. Through the isolated transmission of the two interfaces, the data transceiver module can flexibly adapt to communication needs in different flight scenarios.

[0033] In step S13, the data processing module parses the flight control data and converts it into the format required by the power equipment, while simultaneously compiling the power system feedback data. In one possible implementation, the data processing module is the logic processing unit of the bus repeater, responsible for in-depth parsing of the received flight control data. Specifically, this process includes extracting control parameters from the flight control commands, such as target speed and thrust ratio, and converting these parameters into control signals that the equipment can directly execute, according to the power equipment's communication protocol. For example, flight control commands may be transmitted in a common format, while different types of motors may require specific control signal formats. The data processing module will perform format conversion according to the equipment characteristics to ensure accurate execution of the commands.

[0034] In addition, the data processing module also compiles and processes the data fed back from the power system. After executing commands, the power system returns status information via the bus, such as current speed, temperature, and current parameters. The data processing module organizes this feedback data into a standard format and transmits it to the flight control system through an isolated channel, so that the flight control system can adjust subsequent commands based on the feedback. This two-way data processing mechanism is particularly important in the high-dynamic flight of compound-wing UAVs. For example, in strong winds, the power system may adjust its output due to load changes, and the data processing module can promptly feed back these status changes to the flight control system to ensure stable flight attitude.

[0035] In step S14, the data storage module records the transmission and reception of flight control commands and the feedback data from the power system for subsequent data analysis and fault diagnosis. Specifically, the data storage module is a storage unit within the bus repeater, typically using non-volatile storage media such as flash memory chips, to record the transmission and reception times and content of flight control commands, as well as the feedback data from the power system. This recorded data can be used to analyze the system's operational status after the UAV's flight, for example, by comparing command transmission time and power response time to determine if the communication delay is within a reasonable range. Furthermore, the data recorded by the data storage module can also be used for fault diagnosis; when the system malfunctions, technicians can quickly locate the source of the problem by reviewing the stored records.

[0036] For example, when a compound-wing UAV performs long-endurance missions, the data storage module continuously records every flight control command and its corresponding power feedback data. If a motor responds abnormally during flight, technicians can retrieve the stored data after the mission ends to analyze the command content and feedback status of that motor before the abnormality occurred, thus determining whether the problem is a communication issue or a fault in the equipment itself. This recording mechanism significantly improves system maintainability and reduces the time cost of troubleshooting.

[0037] Step S15: If fluctuations occur in the isolated power bus data, the source of interference is determined based on the data storage module records, and the isolation mode is adjusted to maintain transmission stability. In one embodiment, the isolated power bus data may be subject to external interference during transmission, such as electromagnetic waves or voltage fluctuations, leading to unstable data signals. The bus repeater monitors the data quality of the isolated bus in real time. If fluctuations exceed a preset range, it retrieves historical records from the data storage module for analysis. By comparing the interference patterns in historical data with the current fluctuation characteristics, the system can preliminarily determine the source of interference, such as external electromagnetic interference or internal circuit noise.

[0038] After identifying the source of interference, the bus repeater dynamically adjusts the isolation mode to maintain transmission stability. For example, if the interference originates from an external electromagnetic field, the system may enhance the shielding capability of the isolation circuit or adjust the frequency range of data transmission to avoid the interfering frequency band. If the interference originates from internal circuit noise, data reliability may be improved by reducing the transmission rate or adding verification mechanisms. This dynamic adjustment mechanism is particularly important when compound-wing UAVs perform complex tasks, such as when flying near high-voltage power lines, where external interference may increase significantly. Adjusting the isolation mode can effectively ensure communication continuity.

[0039] Step S2 employs standard bus interfaces, including CAN and RS485, supporting multi-device integration and expansion through device ID modification. Specifically, the power system of a compound-wing UAV typically includes multiple devices, such as multiple motors, servos, and sensors, which need to communicate with the flight control system via bus interfaces. CAN and RS485 interfaces, as standard communication interfaces, can support simultaneous access from multiple devices. The CAN interface, with its high real-time performance and error correction capabilities, is suitable for scenarios requiring high response speeds; the RS485 interface excels in long-distance transmission and anti-interference capabilities, making it suitable for scenarios with widely distributed devices. By combining these two interfaces, the system can flexibly adapt to the needs of different devices.

[0040] Furthermore, to achieve seamless integration of multiple devices, the system supports expansion by modifying device IDs. Each device is assigned a unique ID upon connecting to the bus to distinguish different communication objects. When a new device is added, the system automatically checks if its ID conflicts with existing devices. If a conflict exists, an unused ID is reassigned to ensure communication independence. This design is particularly useful when upgrading or expanding the propulsion system of compound-wing UAVs; for example, when adding additional thrust units, device integration can be quickly completed simply by modifying the ID.

[0041] Step S21: The CAN interface provides high real-time performance and error correction capabilities, and is suitable for low-latency scenarios based on multi-node communication capabilities. In one possible implementation, the CAN interface, as a widely used industrial bus standard, has high data transmission rates and error detection capabilities. In the power system of a compound-wing UAV, the CAN interface is mainly used to connect devices with high real-time requirements, such as the main thrust motor and attitude control servos. Through the CAN interface, flight control commands can be transmitted to the target device in a very short time, while the interface's built-in error correction mechanism can automatically detect and repair data errors during transmission, ensuring the accuracy of the commands.

[0042] For example, when a compound-wing UAV performs rapid maneuvering missions, the flight control system needs to frequently adjust motor speeds and servo angles to maintain stable flight attitude. The high real-time performance of the CAN interface ensures that commands reach the target device within milliseconds, while its multi-node communication capability allows multiple devices to receive commands simultaneously, avoiding communication bottlenecks. This characteristic makes the CAN interface particularly suitable for low-latency scenarios, significantly improving the response speed of the propulsion system.

[0043] Step S22: The RS485 interface provides long-distance transmission and anti-interference capabilities, supports multi-site communication, and integrates devices according to communication specifications. Specifically, the RS485 interface is a differential signal transmission standard with strong anti-interference capabilities and a long transmission distance, suitable for scenarios where devices are widely distributed. In the power system of a compound-wing UAV, the RS485 interface is typically used to connect devices distributed in different locations on the fuselage, such as auxiliary motors located at the wingtips or sensors located at the tail. Through the RS485 interface, these devices can communicate stably with the flight control system, maintaining data integrity even during long-distance transmission.

[0044] In one embodiment, the RS485 interface supports multi-site communication, meaning multiple devices can share the same bus for data exchange. The system assigns a unique address identifier to each device according to the communication specifications, ensuring the orderly transmission of data. For example, when a compound-wing UAV performs a large-scale inspection mission, it may carry multiple sensors for environmental data collection. These sensors are distributed in different locations, and the RS485 interface can achieve unified data transmission, while the interface's anti-interference capability can effectively cope with electromagnetic noise during flight.

[0045] Step S23: Obtain the device access request through the standard bus interface and modify the device ID to achieve seamless integration. In one possible implementation, when a new device accesses the powertrain bus, the system receives its access request via a CAN or RS485 interface. The access request typically includes information such as the device type and communication requirements, and the system assigns a unique ID to the device based on this information. If the new device's default ID conflicts with an existing device, the system automatically adjusts the ID value to ensure the uniqueness of each device on the bus. In this way, new devices can quickly integrate into the existing communication network, achieving seamless integration.

[0046] For example, when upgrading the power system of a compound-wing UAV, it might be necessary to add a new motor unit to increase thrust. After technicians connect the new motor to the bus, the system automatically detects its access request and assigns an unused ID value to the new motor based on the current ID allocation on the bus. The entire process requires no manual intervention, and the device can immediately participate in communication. This flexible ID modification mechanism significantly simplifies the device expansion process and improves the system's scalability.

[0047] Step S24: If the CAN interface load increases, the transmission is distributed via the RS485 interface to balance the load and maintain overall communication efficiency. Specifically, in high-load flight scenarios of compound-wing UAVs, such as when performing rapid climbs or high-speed cruise missions, the CAN interface may experience excessive load due to a surge in data transmission. The system monitors the communication load of the CAN interface in real time. If the load is found to be close to the upper limit, some data transmission tasks will be distributed to the RS485 interface. For example, the CAN interface can continue to handle the transmission of motor control commands with high real-time requirements, while the RS485 interface is responsible for transmitting sensor data or status feedback data with lower real-time requirements.

[0048] In one embodiment, load balancing is coordinated by the bus management module. The bus management module dynamically allocates transmission channels based on data type and priority. For example, when a compound-wing UAV performs complex formation flight missions, multiple devices need to communicate with the flight control system simultaneously. The CAN interface may not be able to fully handle all data traffic. In this case, the system will transmit some low-priority data through the RS485 interface, ensuring that the CAN interface can focus on transmitting high-priority commands. This load balancing mechanism effectively avoids communication congestion and maintains overall communication efficiency.

[0049] Step S3 involves applying a dual-bus communication protocol to ensure that the CAN interface and RS485 interface independently control the power system, achieving bus contention handling, data parsing and distribution, and fault handling to achieve synchronization and switching. Specifically, the dual-bus communication protocol is one of the core designs in this embodiment, aiming to achieve efficient control of the power system through the coordinated operation of the CAN interface and RS485 interface. The dual-bus communication protocol can independently manage the communication tasks of the two buses, ensuring that the power system can stably receive flight control commands and promptly feedback status information under different flight scenarios. Furthermore, the protocol includes functional modules for bus contention handling, data parsing and distribution, and fault handling, used to resolve bus resource contention, optimize data transmission efficiency, and address communication failures.

[0050] In one possible implementation, the dual-bus communication protocol achieves synchronous control of the power system through unified scheduling of the CAN and RS485 interfaces. For example, when a compound-wing UAV switches flight modes, such as from vertical takeoff and landing (VTOL) to horizontal cruise, the flight control system needs to adjust the output power of multiple motors simultaneously. The dual-bus communication protocol will rationally allocate command transmission channels according to device location and communication requirements, ensuring that all devices can receive update commands at the same time. Furthermore, the protocol also supports rapid switching to another bus in case of a failure on one bus, ensuring continuity of control.

[0051] It's important to note that the implementation of the dual-bus communication protocol relies on underlying communication rules and upper-layer management strategies. The underlying communication rules define parameters such as the data frame format and transmission rate of the CAN and RS485 interfaces, ensuring that the two buses can operate independently without interference. The upper-layer management strategy is responsible for the dynamic allocation of bus resources and fault response; for example, when a communication anomaly is detected, it prioritizes switching to the backup bus. This two-layer design provides higher communication reliability when the compound-wing UAV is performing high-risk missions.

[0052] Step S4 involves configuring the bus topology as a tree topology, shortening branch lengths, and adding impedance matching components to reduce signal reflection and improve reliability. Specifically, in the power system bus communication of a compound-wing UAV, optimizing the bus topology is crucial for improving communication stability and reliability. A tree topology is a hierarchical structure consisting of a main bus and multiple branch buses. The main bus connects the flight control system and core equipment, while the branch buses connect secondary devices distributed in different locations, such as motors, servos, or sensors. By configuring the bus topology as a tree structure, the complexity of the signal transmission path can be effectively reduced, lowering the possibility of signal delay and interference.

[0053] In one possible implementation, the tree topology design emphasizes controlling branch length. Excessively long branches can cause signal reflections during transmission, affecting data transmission stability. Therefore, the system minimizes branch bus lengths based on device distribution, making signal transmission paths more direct. Furthermore, to further reduce signal reflections, impedance matching components, such as terminating resistors or matching capacitors, are added at the ends of branch buses or critical nodes to ensure that signals do not experience echo interference due to impedance mismatch during transmission. This design is particularly important for compound-wing UAVs performing long-distance flight missions, significantly improving communication reliability.

[0054] For example, when a compound-wing UAV performs high-altitude inspection missions, multiple sensors and power units are distributed across the fuselage, resulting in long signal transmission distances and significant environmental interference. By adopting a tree-like topology, the system can place the main bus at the center of the fuselage, while branch buses connect to devices on the wings and tail. Furthermore, by shortening branch lengths and adding impedance matching components, signal reflection and interference are effectively reduced, ensuring stable data transmission. This topology design can adapt to the communication needs of complex flight environments.

[0055] Step S41: The tree topology acquires multiple branches and expands them into small bus networks, shortening the total bus length according to the different branch lengths. In one embodiment, the construction process of the tree topology first analyzes the device distribution in the power system to determine the location and communication requirements of each device. The system groups the devices according to their location and function, forming multiple small bus networks, with each small bus network connecting to the main bus as a branch. In this way, the originally complex device connections are decomposed into multiple clearly defined small networks, reducing the total bus length and the complexity of signal transmission.

[0056] Specifically, the reduction in branch length is achieved through optimized device grouping and bus routing. For example, in the wing section of a compound-wing UAV, multiple auxiliary motors and sensors may be distributed. The system divides these devices into a branch network, connecting them to the main bus via a shorter branch bus, rather than extending the bus length for each device individually. This grouping method effectively reduces the total bus length, minimizing signal loss and interference during transmission. In actual flight, such as when performing low-altitude complex terrain reconnaissance missions, this design ensures efficient signal transmission and avoids communication delays caused by excessively long buses.

[0057] Step S42 involves determining the signal transmission path and reducing signal reflection through impedance matching design. In one possible implementation, impedance matching design is a key optimization measure in a tree-like topology. During bus transmission, if a signal encounters a node with impedance mismatch, reflected signals may occur, leading to data transmission errors or delays. To address this issue, the system adds impedance matching components at the ends or connection points of bus branches. For example, a resistor matching the characteristic impedance of the bus is connected at the end of a branch bus to absorb signal energy and prevent reflection.

[0058] For example, when a compound-wing UAV performs long-endurance missions, signals need to be frequently transmitted between the main bus and multiple branch buses. Without impedance matching design, signal reflection may lead to data packet loss or errors. By adding matching resistors at the end of each branch, the system can effectively absorb excess signal energy and ensure the stability of the signal transmission path. This design is particularly effective in high-interference environments, ensuring the accurate arrival of power system control commands.

[0059] Step S43: If the branch length exceeds a preset threshold, a resistor or repeater is added to eliminate reflections and extend the communication distance. Specifically, in a tree topology, although the system tries to shorten the branch length as much as possible, in some cases, such as when devices are too widely distributed, the branch length may still exceed the preset threshold, leading to increased signal attenuation or reflection problems. To solve this problem, the system adds terminating resistors at locations where the branch length exceeds the threshold to eliminate signal reflections; or adds repeaters to enhance signal strength and extend the communication distance.

[0060] In one embodiment, the repeater receives and amplifies the signal, enabling it to be transmitted over longer distances without distortion. For example, when a compound-wing UAV performs a long-range cruise mission, the sensors at the tail may be far from the main bus, with branch lengths exceeding a preset threshold, potentially causing significant signal attenuation during transmission. By adding repeaters midway through the branch, the system can enhance signal strength, ensuring stable transmission of sensor data back to the flight control system. This approach allows for flexible adaptation to diverse device distributions without altering the topology.

[0061] Step S44: Determine the electromagnetic interference level based on the tree topology and adjust the branch structure to improve anti-interference capability and time synchronization. In one possible implementation, the tree topology design also includes dynamic evaluation of the electromagnetic interference level. The system uses a built-in interference detection mechanism to monitor the electromagnetic interference intensity on the bus in real time and adjust the branch structure according to the interference level. For example, if a branch is detected to be subject to strong external electromagnetic interference, the system may adjust the wiring path of that branch to avoid the interference source, or reduce the interference impact by shortening the length of that branch.

[0062] For example, when a compound-wing UAV flies near high-voltage power lines, external electromagnetic interference may increase significantly, affecting the signal transmission quality on the branch bus. The system dynamically adjusts the structure of the affected branches based on interference detection results. This could involve reassigning branch devices to branches with less interference or reducing interference by adding shielding measures. Simultaneously, the adjusted branch structure must ensure time synchronization, meaning the time difference between command reception by all devices remains within an acceptable range. This dynamic adjustment mechanism significantly improves the system's anti-interference capability and ensures communication stability in complex environments.

[0063] Step S31: The dual-bus communication protocol acquires and manages signals from the CAN and RS485 interfaces. Specifically, the dual-bus communication protocol is the core mechanism for enabling the CAN and RS485 interfaces to work together. The system uses this protocol to manage the signals of the two buses in a unified manner, including signal acquisition, distribution, and monitoring. The CAN and RS485 interfaces are responsible for different types of data transmission tasks. For example, the CAN interface mainly transmits control commands with high real-time requirements, while the RS485 interface is responsible for transmitting status data over longer distances or with lower real-time requirements. The dual-bus communication protocol allocates transmission channels rationally according to data characteristics to ensure efficient collaboration between the two buses.

[0064] In one embodiment, the unified management process also includes setting signal priorities. The system assigns different priorities to different data based on the urgency of flight control commands and the importance of the equipment. For example, when a compound-wing UAV is performing an emergency obstacle avoidance mission, control commands involving attitude adjustment are assigned the highest priority and transmitted quickly via the CAN interface, while other non-urgent data is transmitted via the RS485 interface. This unified management approach optimizes bus resource allocation and improves communication efficiency.

[0065] Step S32: The bus contention handling protocol determines the current master bus signal quality. If the signal quality is lower than a predetermined value, it checks the backup bus signal quality and switches to the master bus. In one possible implementation, the bus contention handling protocol is an important component of the dual-bus communication protocol, used to resolve resource contention between the two buses. The system monitors the current master bus signal quality in real time, for example, by detecting the data transmission error rate or signal strength to evaluate its performance. If the master bus signal quality is found to be lower than a predetermined value, the system immediately checks the backup bus signal quality and, if the backup bus has better performance, switches it to the master bus.

[0066] For example, when a compound-wing UAV performs high-altitude flight missions, the CAN interface, as the main control bus, may experience signal quality degradation and increased data transmission error rate due to external interference. The system will detect the signal quality of the RS485 interface. If its performance is found to be better than that of the CAN interface, the RS485 interface will be switched to the main control bus to transmit critical control commands. This dynamic switching mechanism ensures communication continuity and avoids power system control interruption due to a single bus failure.

[0067] Step S321: Obtain the current master control bus signal quality and compare it with a predetermined value. Specifically, the system uses a built-in signal quality detection module to collect real-time operating data of the current master control bus, such as data transmission success rate, error rate, and signal strength. These parameters are compared with preset thresholds to determine whether the master control bus can meet communication requirements. For example, if the error rate of the master control bus exceeds a predetermined value, it indicates that its signal quality can no longer guarantee the reliability of data transmission, and the system will initiate the subsequent switching process.

[0068] In one embodiment, the signal quality detection module continuously records the operating status of the main control bus and generates a quality assessment report. For example, when a compound-wing UAV performs complex formation flight missions, the main control bus needs to handle a large number of data transmission tasks, and the signal quality may degrade due to excessive load. By comparing the current quality with a predetermined value in real time, the system can promptly identify potential problems and provide a basis for subsequent switching decisions.

[0069] Step S322: If the signal quality is lower than a predetermined value, obtain signal quality information from the backup bus. In one possible implementation, when the signal quality of the master bus is determined to be lower than a predetermined value, the system immediately initiates a quality check on the backup bus. The signal quality information of the backup bus includes parameters such as its current data transmission error rate, signal strength, and load status. By obtaining this information, the system can comprehensively assess whether the backup bus has the capability to take over the master control task.

[0070] For example, when a compound-wing UAV is performing a long-distance cruise mission, if the signal quality of the CAN interface, which serves as the main control bus, deteriorates due to interference, the system will detect the operating status of the RS485 interface. If the RS485 interface currently has a low load and a stable signal strength, its quality information will be recorded as a potential switching target. This method of quickly acquiring backup bus information provides a reliable basis for subsequent decisions, ensuring the efficiency of the switching process.

[0071] Step S323: Determine a switching decision based on the fact that the backup bus signal quality is higher than the current master bus. Specifically, the system compares the signal quality parameters of the backup bus with those of the current master bus. If the signal quality of the backup bus is significantly better than that of the master bus, for example, with a lower error rate or higher signal strength, the system will determine a switching decision and promote the backup bus to the master bus to be responsible for subsequent critical data transmission tasks.

[0072] In one embodiment, the handover decision also needs to consider handover costs. For example, when a compound-wing UAV is performing a stable cruise mission, if the main control bus signal quality is lower than a predetermined value but still maintains basic communication, the system may delay the handover to avoid the risk of communication interruption caused by frequent handovers. The handover operation will only be performed when the backup bus signal quality is significantly better than the main control bus. This cautious decision-making mechanism can balance communication stability and handover efficiency.

[0073] Step S324: Adjust the control data source through a switching decision and avoid frequent switching. In one possible implementation, after the switching decision is determined, the system adjusts the transmission channel of the control data, switching the data source from the original master bus to the new master bus. Simultaneously, to avoid communication instability caused by frequent switching, the system sets a certain switching cooldown time; that is, even if the signal quality fluctuates again after a switching is completed, a new switching operation will not be immediately executed.

[0074] For example, when a compound-wing UAV performs a vertical takeoff and landing mission, if the CAN interface signal quality deteriorates, the system decides to switch to the RS485 interface as the main control bus. After the switch is complete, the system will lock the RS485 interface as the main control bus for a period of time, and will not immediately switch back even if the CAN interface signal quality briefly recovers. This design, which avoids frequent switching, reduces the risk of communication interruption and ensures the continuity of power system control.

[0075] Step S325: Determine the synchronization status after the switchover and distribute update commands to maintain the continuity of powertrain control. Specifically, after the switchover is completed, the system will check the synchronization status between the new master bus and the powertrain devices to ensure that all devices can receive update commands in a timely manner. If an abnormal synchronization status is detected, such as some devices not responding to commands from the new master bus, the system will redistribute update commands to ensure that all devices are in the same state.

[0076] In one embodiment, the determination of synchronization status also includes detecting the execution time of instructions. For example, when a compound-wing UAV switches flight modes, the system sends generator speed adjustment instructions via a new master control bus and checks whether each motor completes the adjustment within a specified time. If a delay in the response of a motor is detected, the system resends the instruction via the new master control bus to ensure the continuity and coordination of the overall control of the power system.

[0077] Step S33: The data parsing and distribution protocol configures device IDs and priorities based on the transmission baud rate and data rate, and packets data for transmission to ensure the load rate remains below a preset threshold. In one possible implementation, the data parsing and distribution protocol is a crucial functional module of the dual-bus communication protocol, used to optimize data transmission efficiency. The system configures a unique ID for each device based on the transmission baud rate and data rate, and sets priorities according to data type and device importance. Simultaneously, the system groups and packages data to ensure the bus load rate remains below the preset threshold, preventing communication congestion.

[0078] For example, when a compound-wing UAV performs multi-mission flights, the flight control system needs to send control commands to multiple devices and receive status feedback data simultaneously. The data parsing and distribution protocol allocates high-priority data to the CAN interface and low-priority data to the RS485 interface based on transmission requirements, and reduces the number of data transmissions through packetization to ensure balanced bus load. This optimized design significantly improves communication efficiency.

[0079] Step S331: Obtain the transmission baud rate and data rate, and set communication requirements. Specifically, the system monitors the bus's transmission baud rate and data rate in real time to determine the current communication capabilities. The baud rate reflects the frequency of the bus's transmitted signals, while the data rate reflects the actual amount of effective data transmitted. Based on these parameters, the system sets communication requirements, such as allocating higher transmission priority to high-real-time data and lower transmission frequency to large-volume data.

[0080] In one embodiment, the communication requirements are also set considering the characteristics of the flight mission. For example, when a compound-wing UAV performs a rapid maneuver mission, the system prioritizes the transmission rate of control commands, adjusting the baud rate to a higher level to ensure that commands reach the target device in a timely manner. This dynamic setting method can flexibly adapt to the communication needs of different flight scenarios.

[0081] Step S332: Configure 0 to multiple configurable IDs, where each ID contains a fixed number of bytes of data to be transmitted. In one possible implementation, the system assigns a unique ID to each device accessing the bus to distinguish different communication objects. The ID typically contains a fixed-byte data field to store basic information about the device and its communication requirements. In this way, the system can quickly identify the target device and allocate appropriate transmission resources to it.

[0082] For example, when expanding the power system of a compound-wing UAV, newly added motor devices are assigned a new ID identifier containing their device type and communication priority information. Based on the fixed-byte data in the ID, the system determines whether the motor requires a high real-time transmission channel and allocates a CAN or RS485 interface accordingly. This ID configuration mechanism simplifies the multi-device management process.

[0083] Step S333: Packet data according to the data volume, data type, and rate of the device, and send it using the corresponding ID. Specifically, the system groups and packages the data into data packets based on the data volume, data type, and required transmission rate of the device, and sends them to the target device using the device's corresponding ID. The packet assembly process reduces the number of data transmissions, lowers the bus load, and ensures the orderliness of data transmission.

[0084] In one embodiment, the allocation of packaged data also needs to consider the data type. For example, when a compound-wing UAV performs environmental monitoring tasks, the amount of environmental data collected by the sensors is large but the real-time requirements are low. The system will package this data into a large data packet and transmit it through the RS485 interface; while the amount of motor control command data is small but the real-time requirements are high, it will be packaged separately and transmitted through the CAN interface. This classification and packaging method can optimize the utilization of bus resources.

[0085] Step S334: Determine the bus load rate. If it is close to a preset threshold, optimize the data distribution to achieve a balanced distribution and reduce peak values. In one possible implementation, the system monitors the bus load rate in real time, which is the ratio of the current data transmission volume to the bus's maximum carrying capacity. If the load rate is found to be close to the preset threshold, it indicates that the bus may face congestion risks. The system will optimize the data distribution strategy, such as delaying the transmission of some low-priority data or allocating data to bus channels with lower loads to achieve load balancing.

[0086] For example, when a compound-wing UAV performs high-load flight missions, the load rate of the CAN interface may approach its limit. The system will then transfer some non-critical data to the RS485 interface for transmission and adjust the data transmission frequency to reduce peak load. This dynamic optimization mechanism can effectively avoid communication bottlenecks and ensure the stability of bus operation.

[0087] Step S335 involves configuring device IDs and priorities to determine data transmission efficiency and reduce conflicts. Specifically, by configuring unique IDs and priorities for devices, the system can clearly define the order of data transmission and channel allocation, reducing data conflicts between devices. For example, data from high-priority devices will be transmitted first, while data from low-priority devices will be sent when the bus is idle. This approach can significantly improve data transmission efficiency.

[0088] In one embodiment, conflict reduction also includes controlling the timing of data transmission. For example, when a compound-wing UAV performs a formation flight mission, multiple devices may request to send data simultaneously. The system will arrange the transmission order according to the device ID and priority to avoid data conflicts and ensure smooth communication. This design can guarantee the stable operation of the propulsion system in high-concurrency scenarios.

[0089] Step S34: The fault handling protocol determines bus data faults. If a bus data anomaly is detected, communication on that bus is terminated and the system switches to a normal bus. In one possible implementation, the fault handling protocol is a crucial safeguard mechanism for the dual-bus communication protocol, used to handle abnormal situations in bus communication. The system monitors the bus data transmission status in real time. If a data anomaly is detected on a bus, such as a high packet loss rate or transmission delay exceeding acceptable limits, the system immediately terminates the communication task on that bus and switches data transmission to another normally operating bus.

[0090] For example, when a compound-wing UAV is performing high-altitude missions, if the CAN interface experiences abnormal data transmission due to external interference, the system will terminate the CAN interface communication and switch critical data to the RS485 interface for transmission. This rapid switching mechanism can avoid communication interruptions caused by a single bus failure, ensuring the continuity of power system control.

[0091] Step S341: Acquire bus data and determine if the data of a certain bus device is abnormal. Specifically, the system will collect the data transmission status on the bus in real time through the fault detection module, including parameters such as data packet integrity and transmission time. If an abnormality is found in the data of a certain bus device, such as the loss of multiple consecutive data packets or the transmission time exceeding the expected range, the device or bus will be marked as abnormal.

[0092] In one embodiment, anomaly detection also includes a consistency check of the data content. For example, when a compound-wing UAV is performing an attitude adjustment task, if the data fed back by a certain motor is inconsistent with the flight control command, the system will determine that there may be an anomaly on the bus where that motor is located and initiate subsequent fault handling procedures. This meticulous detection method can quickly locate the source of the problem.

[0093] Step S342: If an anomaly is detected, the corresponding data is retrieved from another bus and its normality is verified. In one possible implementation, when a bus is determined to be abnormal, the system will attempt to retrieve the data of the corresponding device from another bus and verify its normality. For example, if the motor control data transmitted via the CAN interface is abnormal, the system will re-retrieve the motor data via the RS485 interface and check whether the data is complete and meets expectations.

[0094] For example, when a compound-wing UAV is performing an emergency mission, if the CAN interface data is abnormal, the system will obtain backup data through the RS485 interface and verify whether it can correctly reflect the motor status. If the backup data is normal, the system will immediately switch the transmission channel to ensure the accurate transmission of control commands. This verification mechanism can improve the reliability of fault handling.

[0095] Step S343: Based on the verification result, terminate the communication on the faulty bus and switch to the normal bus. Specifically, if the data obtained through another bus is verified as normal, the system will terminate the communication task on the faulty bus and switch all relevant data transmissions to the normal bus. During the switching process, the system will ensure the continuity of data transmission to avoid instruction loss or delay due to the switching.

[0096] In one embodiment, the switching process also includes resynchronizing the device states. For example, when a compound-wing UAV performs a flight mode switch, if one bus fails, the system will resend the synchronization command through the normal bus to ensure that all devices are in the same state. This approach ensures the stable operation of the power system after a fault switch.

[0097] Step S344: Determine the communication status of the device after the switchover and maintain normal communication. In one possible implementation, after the switchover is complete, the system will detect the communication status of the target device on the new bus, for example, checking whether the device can normally receive commands and feedback data. If an abnormal communication status is found, the system will further adjust the transmission parameters or resend the commands to ensure that communication is restored to normal.

[0098] For example, when a compound-wing UAV is performing a long-endurance mission, if a device experiences a brief communication interruption due to bus switching, the system will re-establish a connection via the new bus and send test data packets to verify the communication status. In this way, the system can quickly restore normal communication and ensure the smooth execution of the mission.

[0099] Step S345 involves isolating the fault through a fault handling protocol and imbuing it with self-healing capabilities to improve system reliability. Specifically, the fault handling protocol can not only switch buses but also prevent fault propagation by isolating faulty devices or buses. For example, if a device continuously sends abnormal data, the system will temporarily isolate that device, prohibiting it from participating in bus communication, while completing the task through other devices or buses.

[0100] In one embodiment, the self-healing feature also includes dynamic recovery attempts for a faulty bus. For example, during the flight of a compound-wing UAV, if the CAN interface is temporarily isolated due to interference, the system will attempt to re-enable the bus after the interference disappears and verify its performance using test data. This self-healing mechanism can maximize the utilization of bus resources and improve the overall reliability of the system.

[0101] Step S35: The synchronization status is determined and control commands are distributed via a dual-bus communication protocol to achieve seamless switching and high synchronization. In one possible implementation, the dual-bus communication protocol ensures the synchronization status of power system equipment when switching between different buses through unified management of the CAN interface and RS485 interface. The system periodically checks the command reception time and response status of all devices. If a synchronization deviation is detected, a calibration command is distributed via the main control bus to ensure that all devices are in the same state.

[0102] Example 1: This invention addresses the challenges of current point-to-point communication methods and the complex power structure of large vertical take-off and landing (VTOL) UAVs by designing a power bus communication system with high anti-interference capabilities, high reliability, simple wiring, low communication latency, and strong scalability.

[0103] The power bus communication system comprises the following four parts: I. Bus Repeater Design: such as Figure 1 As shown, the entire power system adopts a digital control mode, which uses a bus converter to convert power control commands from the flight controller into control commands from the electronic speed controller. It adopts an isolated communication mode, which enhances the anti-interference capability of the power system and the flight control and navigation system.

[0104] II. Standard Bus Interface Design: The powertrain system utilizes CAN and RS485 interfaces. CAN and RS485 buses, as two widely used universal standard interfaces, exhibit strong expandability. When adding or replacing devices, users only need to follow the communication specifications of these two standard interfaces and simply modify the ID of the newly connected device to easily achieve seamless integration and communication. This convenience greatly reduces the complexity of system integration and maintenance, making CAN and RS485 buses the preferred communication solutions in industrial automation, automotive manufacturing, and other multi-device communication scenarios.

[0105] III. Dual-bus communication protocol: such as Figure 2As shown, due to the differences and similarities in the bus structure of CAN bus and RS485 bus, the design of this protocol ensures that each bus can independently control the power system. This protocol not only covers core functions such as bus contention handling, bus fault diagnosis, and bus data parsing and distribution, but also achieves high synchronization and seamless switching between the two bus systems.

[0106] IV. Bus topology design: such as Figure 3 As shown, since the bus structures of CAN bus and RS485 bus are very similar, both support various topologies such as bus topology, star topology, tree topology, and hybrid topology. By designing the topology, the length of bus branches can be reduced, and for long branches in linear topologies, resistors or repeaters can be added to eliminate signal reflections and extend communication distance.

[0107] The working principle of this invention is as follows: 1. Bus Repeater Design: The system comprises three main parts: a data transceiver module, a data processing module, and a data storage module. The data transceiver module is divided into two parts: flight control data (non-isolated) and power bus data (isolated). The former receives flight control commands and forwards power system data, while the latter transmits flight control commands and power system data in isolation via RS485 and the CAN bus. The data processing module parses the flight control data, converts it into the format required by the power system, and compiles the power system feedback data. The data storage module records all data transmitted and received by the flight control system and the power system feedback data for later data analysis and fault diagnosis.

[0108] 2. Standard Bus Interface Design: CAN and RS485 are both widely used standard bus interfaces. The CAN bus interface design is renowned for its high real-time performance, multi-node communication capabilities, and advanced error detection and correction functions, making it particularly suitable for communication scenarios requiring high reliability and low latency, such as automotive control systems. The RS485 interface design, on the other hand, is widely used in industrial automation, intelligent buildings, and remote monitoring due to its strong anti-interference capabilities, long-distance transmission capabilities, and support for multi-site communication.

[0109] 3. Dual-bus communication protocol design: CAN and RS485 buses are essentially two different buses. For heterogeneous bus systems, a unified communication protocol is needed for management. This protocol includes a bus contention handling protocol, a bus data parsing and distribution protocol, and a bus fault handling protocol.

[0110] a. Bus contention processing protocol: The dual-bus control protocol uses CAN and RS485 buses. It determines the source of power system control data through bus contention mode, avoiding the problem of frequent switching of the main control bus between the two systems. The bus contention protocol judges the signal quality of the current main control bus. If the current bus quality is lower than a predetermined value, it starts to detect if the signal quality of the backup bus is higher than that of the main bus and switches the backup bus to the main control bus. b. Bus Data Parsing and Distribution Protocol: The protocol specifies the transmission baud rate and data transmission rate to ensure that the bus load rate is below 50%. At the same time, the protocol specifies a set of communication requirements, which define the communication protocol of the bus devices. It includes the configuration of the ID and priority of each device on the bus. It contains 0 to 1024 configurable IDs, each ID containing 8 bytes of data to be sent. Devices on the bus can send data in packets according to their own data volume, data type and rate through the corresponding ID. c. Bus Fault Handling Protocol: By judging the data on the bus, if a bus device experiences a fault in one of its bus data, the bus fault handling protocol can determine whether the data on another bus of the device is normal, terminate the faulty bus communication of the device, and switch to the normal bus to maintain the normal communication of the device.

[0111] 4. Bus Topology Design: Due to the high electromagnetic interference immunity, millisecond-level time synchronization, and high reliability required for this bus system, a tree topology is adopted. This topology has multiple branches of varying lengths. The branches expand in a tree structure, and each branch can be viewed as a small bus or star network. This topology significantly shortens the overall bus length. Furthermore, the impedance matching of the dual-bus system is carefully designed to ensure stable signal transmission on the bus and reduce signal reflections.

[0112] Based on the above working principle, the present invention will be further explained with reference to specific examples: Taking the power system of a certain 100kg-class large vertical takeoff and landing compound wing UAV as an example, the implementation process of this invention is described in detail, and a new test process chapter is added, from test environment setup, test item design, test step execution to test result analysis, to fully verify the effectiveness of the communication method: (I) System Configuration 1. Bus repeater selection: A customized bus repeater based on the STM32H7 series microcontroller is adopted. The data transceiver module integrates TI's SN65HVD230 CAN transceiver (supporting isolation voltage of 2500Vrms) and MAXIM's MAX485RS485 transceiver (supporting ±15kV ESD protection); the data storage module is configured with 16GB NAND Flash, supporting continuous data storage for 72 hours (sampling frequency of 100Hz).

[0113] 2. Power Equipment Configuration: The drone is equipped with 6 600W brushless motors (model: T-MotorU8) and matching ESCs (model: T-MotorFLAME80A), 2 sets of 24V / 50Ah lithium batteries and BMS (model: JBD24S), and 1 IMU attitude sensor (model: BMI088). All equipment integrates CAN2.0B and RS485 dual interfaces and supports custom ID configuration.

[0114] 3. Bus interface parameters: The CAN bus baud rate is set to 500kbps (to meet the real-time requirements of power control), and the RS485 bus baud rate is set to 115200bps (to adapt to low-speed status feedback data); through protocol optimization, the bus load rate is stably controlled within 40% (10% redundancy is reserved to cope with sudden data).

[0115] 4. ID and Priority Configuration: A 10-bit binary ID encoding is used. The flight controller ID is 0000000001 (highest priority), the IDs of the 6 ESCs are 0000000010-0000000111, the 2 BMS IDs are 0000001000-0000001001, and the IMU ID is 0000001010 (lowest priority). The data transmission priority is sorted as follows: "flight controller control commands > IMU attitude data > ESC status feedback > BMS battery data".

[0116] (ii) Topology Deployment A tree-like topology is used for bus routing, balancing signal stability and ease of maintenance. 1. Main bus design: AWG24 shielded twisted pair cable is selected as the main bus for CAN and RS485. The shielding layer material is tin-plated copper mesh (95% coverage). The main bus length is 4.8m (controlled within 5m to reduce signal attenuation). 120Ω terminating resistors are connected to both ends of the main bus (matching the characteristic impedance of the CAN bus). There are no branches at the intermediate nodes to avoid signal reflection.

[0117] 2. Branch Node Configuration: Four branches extend from the main bus. Branch 1 (1.2m in length) connects to ESCs 1-2, Branch 2 (1.5m in length) connects to ESCs 3-4, Branch 3 (0.8m in length) connects to ESCs 5-6, and Branch 4 (1.0m in length) connects to BMS1-2 and IMU. Each branch is equipped with a 75Ω matching resistor at the end (to adapt to RS485 bus characteristics). The connection between the branch and the main bus uses a waterproof aviation plug (IP67 protection rating) to meet outdoor flight requirements.

[0118] 3. Grounding and anti-interference treatment: All bus shielding layers are grounded at one end (grounded only at the flight controller end to avoid ground loop interference), and the grounding resistance is ≤3.5Ω; power cables and bus cables are laid separately (spacing ≥10cm), and perpendicular crossing is used at the crossing points (to reduce electromagnetic coupling), further reducing the interference of high-voltage power lines on bus signals.

[0119] (III) Implementation of Communication Process 1. Normal communication process: 2. Command Issuance: The flight controller sends a motor speed control command every 10ms (ID: 0000000001, data frame format: 8 bytes, including the target speed (unit: rpm) of motors 1-6 and the command check code); After receiving the command, the flight controller data unit (non-isolated) of the bus repeater converts it into a binary format that the ESC can recognize (parses the check code to confirm the validity of the command), and then distributes it to the corresponding ESC through the CAN bus (default main control bus).

[0120] Data feedback: The ESC feeds back status data every 20ms (ID: 0000000010-0000000111, data frame includes real-time speed, operating current, winding temperature, and fault code), the BMS feeds back battery data (voltage, current, SOC, cycle count) every 500ms, and the IMU feeds back attitude data (angular velocity, acceleration, Euler angle) every 5ms. All feedback data is transmitted back to the bus repeater via the CAN bus. After being compiled by the data processing module according to the flight control protocol, the data is sent to the flight control unit by the flight control data unit. At the same time, the data storage module records the entire data in the format of "timestamp + device ID + data content" (storage accuracy 1ms).

[0121] 3. Bus switching scenario: 4. Triggering conditions: When the drone flies in a strong electromagnetic environment (such as near a high-voltage power line), the CAN bus bit error rate rises to 0.12% due to interference (exceeding the predetermined threshold of 0.1%), and the bus contention processing protocol detects this anomaly in real time.

[0122] The switching process: The protocol first initiates backup bus (RS485) signal detection to confirm that its bit error rate is only 0.008% (below the threshold). Then, the master control switch is completed within one communication cycle (10ms), and the ESC control commands and status feedback data are switched to RS485 bus transmission. There is no data loss during the switching process, the flight controller does not have a command timeout alarm, and the UAV attitude is stable (pitch angle fluctuation ≤0.5°).

[0123] 5. Fault handling scenarios: 6. Fault Trigger: Artificially simulate a CAN interface fault of ESC 3 (disconnect the CAN bus connection). The bus fault handling protocol detects a CAN data interruption of ESC 3 within one data frame cycle (20ms) (no data received for 3 consecutive times).

[0124] Fault Recovery: The protocol immediately detects the RS485 bus data of ESC 3 (normal reception), then terminates the CAN bus communication and switches to RS485 bus to transmit the control commands and status feedback of ESC 3; at the same time, the data storage module records the fault information (fault device ID: 0000000011, fault type: CAN bus interruption, fault time: 2024-05-10 14:32:15.678), and the flight controller displays the alarm "ESC 3 CAN fault, switched to RS485", but the UAV still maintains normal flight (motor 3 speed fluctuation ≤10rpm).

[0125] 7. Equipment expansion scenarios: 8. Expanded requirements: Add one spare motor (T-MotorU8) and ESC (T-MotorFLAME80A), which need to be connected to the system to achieve coordinated control.

[0126] Implementation steps: ① Connect the wires according to the RS485 standard interface specifications (connect the A / B lines to the free terminals of branch 2); ② Configure the ESC ID as 0000000111 (the original ID is carried over to avoid conflict) via the host computer, and set the priority to "ESC 7" (lower than the original ESC); ③ Restart the bus repeater, the system automatically recognizes the new device, and the flight controller can issue speed commands without modifying the program; the entire expansion process takes 1.5 hours and does not require disassembling the original equipment or rewiring.

[0127] (iv) Testing process To verify the anti-interference capability, reliability, real-time performance, and scalability of this communication method, four types of test items were designed. A test environment was built using professional testing equipment, and the test was strictly executed according to the steps, with data recorded. 1. Test environment setup 2. Test Items and Procedures (1) Anti-interference test (verify communication stability under electromagnetic environment) Test objective: To simulate electromagnetic interference in the high-voltage power system of a large vertical take-off and landing UAV and to verify the anti-interference capability of the bus communication.

[0128] Test steps: i. Place the UAV power system (including bus, ESC, BMS) in the test area of ​​the electromagnetic interference generator, set the interference type to "pulse group interference" (compliant with IEC61000-4-4 standard), and the interference voltages to 1kV, 2kV, and 3kV (covering the interference intensity that may be encountered in actual flight).

[0129] ii. Start the system and simulate hovering of the UAV on the semi-physical simulation platform (motor speed stabilized at 1500 rpm). Continuously monitor the bus error rate using the CANoe analyzer and record the bus signal waveforms (amplitude, noise voltage) using an oscilloscope. The test duration is 30 minutes per voltage level.

[0130] iii. Compare the bit error rate and signal amplitude changes under no interference (interference voltage 0kV) and interference conditions to determine whether the anti-interference performance meets the standards (bit error rate ≤ 0.1%, signal amplitude fluctuation ≤ 10%).

[0131] (2) Reliability testing (verifying dual-bus switching and fault handling capabilities) Test objective: To verify the switching response speed and fault recovery rate during bus failures, and to ensure that the system has no single point of failure.

[0132] Test steps: i. Under normal communication conditions, manually disconnect the CAN bus via CANoe (simulating a main control bus failure), record the bus switching delay (the time from the occurrence of the failure to the backup bus taking over the communication), repeat the test 100 times, and calculate the average switching delay.

[0133] ii. Restore the CAN bus, manually disconnect the RS485 bus (simulate a backup bus failure), record whether the flight control command is issued normally and whether the ESC continuously feeds back data, repeat the test 50 times, and calculate the fault recovery rate (recovery rate required to be 100%).

[0134] iii. Repeat steps 1-2 in a high and low temperature test chamber (-40℃, 25℃, 60℃) to verify the reliability under extreme temperatures (the switching delay should be ≤20ms and the recovery rate should be 100%).

[0135] (3) Real-time performance test (verify communication latency and synchronization) Test objective: To verify the delay time and data synchronization of bus communication to meet the high real-time requirements of the power system.

[0136] Test steps: i. Simultaneously collect the flight control command transmission timestamp (T1), bus repeater reception timestamp (T2), ESC reception timestamp (T3), ESC feedback transmission timestamp (T4), and flight control reception feedback timestamp (T5) using a data acquisition device. The sampling frequency is 1kHz, and the test duration is 1 hour.

[0137] ii. Calculate key indicators: ① Command delay (T3-T1): the time from flight control command to ESC; ② Feedback delay (T5-T4): the time from ESC feedback to flight control; ③ Synchronization error (the time difference between different ESCs receiving commands at the same moment), and calculate the average and maximum values.

[0138] iii. Requirements: instruction delay ≤ 10ms, feedback delay ≤ 15ms, synchronization error ≤ 5ms.

[0139] (4) Scalability test (verify the ease of adding or removing equipment and its compatibility) Test objective: To verify the configuration complexity and system compatibility when adding / removing devices, and to evaluate the efficiency of expansion.

[0140] Test steps: i. New device test: Add ESC 7 according to the steps in “Implementation Process 4”, record the total time from wiring to normal communication (including ID configuration and system restart), and test the communication compatibility between the new device and the original device (whether there is a data conflict).

[0141] ii. Device removal test: Disconnect the ESC 2 wiring and record whether the system automatically recognizes the device offline (flight control alarm time), and whether the communication of the original devices (ESC 1, 3-6) is affected (whether the bit error rate and delay change).

[0142] iii. Multi-device expansion test: Gradually add up to 10 ESCs (within the maximum supported ID number), test the bus load rate change (load rate required ≤50%), and evaluate the system's maximum expansion capability.

[0143] (V) Analysis of Test Results The above tests showed that all indicators met the design requirements, verifying the effectiveness of the proposed communication method. The specific results are as follows: 1. The results of the anti-interference test are shown in Table 1.

[0144] Table 1 Conclusion: Under 3kV burst interference, the bit error rate of the dual bus is still less than 0.1%, and the signal amplitude fluctuation is controlled within 10%, and the anti-interference capability meets the requirements of high-voltage power systems.

[0145] 2. The reliability test results are shown in Table 2.

[0146] Table 2 Conclusion: The switching delay of both buses is ≤10ms, the fault recovery rate is 100%, the performance is stable under extreme temperatures, and there is no risk of single point of failure.

[0147] 3. The results of the real-time performance test are shown in Table 3.

[0148] Table 3 Conclusion: The command delay, feedback delay, and synchronization error all meet the design requirements, ensuring real-time control of the power system.

[0149] 4. The results of the scalability test are shown in Table 4.

[0150] Table 4 Conclusion: The equipment expansion is quick and highly compatible. Even with 10 ESCs, the bus load rate is still below 50%, and the expansion capability meets the needs of large UAVs with multiple power devices.

[0151] (vi) Summary of Implementation Results This implementation case demonstrates the following advantages of the power system bus communication method of the present invention through system configuration, topology deployment, communication verification, and comprehensive testing of a 100kg-class large vertical takeoff and landing compound wing UAV: 1. Strong anti-interference capability: It maintains a low bit error rate even under 3kV electromagnetic interference, and is suitable for the complex electromagnetic environment of high voltage and high power power systems; 2. High reliability: Dual-bus switching delay ≤10ms, fault recovery rate 100%, stable performance under extreme temperatures; 3. Excellent real-time performance: instruction delay ≤10ms, synchronization error ≤5ms, meeting the high-frequency control requirements of the power system; 4. Good scalability: Adding new equipment takes ≤1.5 hours, supports collaborative communication of more than 10 ESCs, and reduces system integration costs; 5. Easy maintenance: The tree-like topology is clear, and the data storage module facilitates fault tracing, improving maintenance efficiency by more than 60%.

[0152] This method can be directly extended to large vertical take-off and landing (VTOL) hybrid unmanned aerial vehicles (UAVs) weighing 50-200kg. By adjusting the bus baud rate, topology branch length, and number of IDs, it can be adapted to the power system communication requirements of UAVs of different tonnages.

[0153] The above provides a detailed description of a bus communication system and method based on a compound-wing unmanned aerial vehicle (UAV) power system, as provided in the embodiments of this application. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and its core ideas; furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

[0154] Certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The terms "comprising" and "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising / including but not limited to". "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error. The following descriptions in the specification are preferred embodiments for carrying out this application; however, these descriptions are for the purpose of illustrating the general principles of this application and are not intended to limit the scope of this application. The scope of protection of this application shall be determined by the appended claims.

[0155] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a product or system comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a product or system. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the product or system that includes said element.

[0156] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0157] The foregoing description illustrates and describes several preferred embodiments of this application. However, as previously stated, it should be understood that this application is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the application concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of this application should be within the protection scope of the appended claims.

Claims

1. A bus communication system based on a compound-wing unmanned aerial vehicle (UAV) power system, characterized in that, The bus communication system based on the power system of the compound wing UAV includes: a bus repeater, a standard bus interface module, a dual bus communication protocol module, and a bus topology module; The bus repeater includes a data transceiver module, a data processing module, and a data storage module. The data transceiver module includes a non-isolated unit and an isolated unit. The non-isolated unit is connected to the flight control and navigation system of the UAV power system, and the isolated unit is connected to the standard bus interface module. The data transceiver module is connected to the data storage module through the data processing module. The standard bus interface module includes a CAN bus interface unit and an RS485 bus interface unit; The dual-bus communication protocol module includes a bus contention processing protocol unit, a data parsing and distribution protocol unit, and a fault handling protocol unit. The bus contention processing protocol unit, the data parsing and distribution protocol unit, and the fault handling protocol unit are all connected to both the CAN bus interface unit and the RS485 bus interface unit. The bus topology module adopts a tree topology, including a trunk bus and several branch buses, and the several branch buses are connected to the bus repeater through the trunk bus.

2. The bus communication system based on the power system of a compound-wing unmanned aerial vehicle according to claim 1, characterized in that, The bus repeater is installed in an electromagnetic shielding cabin, and the bus cable is a shielded twisted pair with a characteristic impedance of 120Ω. The isolation unit of the data transceiver module adopts an electrical isolation design, and the data storage module is equipped with a storage medium of ≥16GB for recording flight control command data, power system feedback data, and bus communication status data.

3. The bus communication system based on the power system of a compound-wing unmanned aerial vehicle according to claim 1, characterized in that, The CAN bus interface unit supports baud rates of 250kbps, 500kbps, and 1Mbps, while the RS485 bus interface unit supports baud rates of 9600bps to 115200bps. Both types of interface units support device ID configuration and seamless integration.

4. The bus communication system based on the power system of a compound-wing unmanned aerial vehicle according to claim 1, characterized in that, The bus contention processing protocol unit realizes automatic switching between the master bus and the backup bus by detecting the bus signal quality. The switching response time is ≤50ms. The bus signal quality includes the signal-to-noise ratio and the bit error rate.

5. The bus communication system based on the power system of a compound-wing unmanned aerial vehicle according to claim 1, characterized in that, The data parsing and distribution protocol unit supports 0 to 1024 configurable device IDs, with each ID corresponding to 8 bytes of data to be sent, and the bus load rate is controlled below 50%.

6. The bus communication system based on the power system of a compound-wing unmanned aerial vehicle according to claim 1, characterized in that, The fault handling protocol unit monitors bus data in real time. When a bus of a device fails, it switches to another normal bus of the same device. The fault detection cycle is ≤5ms.

7. The bus communication system based on the power system of a compound-wing unmanned aerial vehicle according to claim 1, characterized in that, The trunk bus length of the tree topology is ≤10m, the branch bus length is ≤5m, and the long branch line length is >3m and is configured with matching resistors or repeaters.

8. The bus communication system based on the power system of a compound-wing unmanned aerial vehicle according to claim 1, characterized in that, The data processing module uses a microcontroller with a main frequency of ≥480MHz, which supports synchronous parsing and format conversion of CAN bus and RS485 bus data.

9. The bus communication system based on the power system of a compound-wing unmanned aerial vehicle according to claim 1, characterized in that, The CAN bus interface unit supports communication between up to 110 nodes, and the RS485 bus interface unit supports communication between up to 32 nodes, and has error detection and fault tolerance functions.

10. A bus communication method based on a compound-wing unmanned aerial vehicle (UAV) power system, characterized in that, The bus communication method based on the power system of the compound wing UAV is implemented by the bus communication system based on the power system of the compound wing UAV as described in any one of claims 1-9. The bus communication method based on the power system of the compound wing UAV is used to realize the secure transmission of data between the power system of the compound wing UAV and the flight control and navigation system.

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