Master-slave internal bus communication design method for aerospace embedded system

Abstract

The invention belongs to the technical field of spaceflight embedded systems, and particularly relates to a master-slave internal bus communication design method for a spaceflight embedded system. The method comprises the following steps: designing an internal bus communication protocol frame structure and realizing communication between a master device and a slave device according to the frame structure; the designed internal bus communication protocol frame structure comprises a master / slave identifier, a frame type and a frame identifier, and the master / slave identifier is used for distinguishing whether a node for sending data in internal bus communication is a master node or a slave node; the frame type is used for distinguishing data and no data in an effective data area and is divided into a data frame and a remote frame; the frame identification is used for subdividing a data frame and a remote frame and determining the purpose of the frame, and the data frame comprises a conventional parameter-free instruction frame, a conventional parameter-carrying instruction frame, a telemetry request frame and a data transmission frame.

Description

Technical Field

[0001] This invention belongs to the field of aerospace embedded system technology, specifically relating to a master-slave internal bus communication design method for aerospace embedded systems. Background Technology

[0002] In aerospace embedded systems, efficient and reliable data interaction between the master device and multiple slave devices is crucial for system stability. This is especially true for scenarios with high system complexity and extremely high requirements for reliability, real-time performance, stability, and productization, such as spacecraft control, satellite communication, and spacecraft navigation. In the aerospace environment, systems must cope with complex conditions such as extreme temperatures, radiated interference, and electromagnetic noise, while also demanding deterministic data transmission, interference immunity, and rapid response capabilities. Traditional communication methods suffer from the following problems: 1. The communication method is limited and cannot adapt to the needs of different communication scenarios; 2. Low data transmission efficiency, which cannot meet the real-time requirements of aerospace systems; 3. The lack of a sound frame structure design makes it impossible to guarantee data integrity and reliability; 4. The system has poor scalability and maintainability, making it difficult to adapt to the needs of complex tasks. Summary of the Invention

[0003] In view of this, the present invention proposes a master-slave internal bus communication design method for aerospace embedded systems, which can significantly improve the stability, efficiency, real-time performance, reliability and maintainability of aerospace embedded systems.

[0004] The technical solution for implementing the present invention is as follows: A master-slave internal bus communication design method for an aerospace embedded system, the aerospace embedded system comprising: a master device: responsible for unified scheduling and management of all slave devices; multiple slave devices: each undertaking different tasks; and an internal bus: used for data transmission between the master device and the slave devices; the method comprising: designing an internal bus communication protocol frame structure and implementing communication between the master and slave devices according to the frame structure; The design of the internal bus communication protocol frame structure includes a master / slave identifier, a frame type, and a frame identifier. The master / slave identifier distinguishes whether the node sending data in the internal bus communication is a master or a slave node. The frame type distinguishes whether the valid data area contains data or not, and is divided into data frames and remote frames. The frame identifier further subdivides data frames and remote frames to determine the frame's purpose. Data frames include: regular command frames without parameters, regular command frames with parameters, telemetry request frames, and data transmission frames. The communication between master and slave devices based on the frame structure includes: command response and data query; Command response method: The master device sends a command to the slave device, the slave device receives and parses the command according to the frame format definition, and performs the corresponding operation according to the command requirements; Data query method: The master device sends a data query request command to the slave device as needed. After receiving the data query request command, the slave device sends the relevant information to the master device through the internal bus, so that the master device can keep track of the status of the slave device in a timely manner.

[0005] Optionally, the internal bus communication protocol frame structure of the present invention further includes the following fields: Frame header: A specific sequence of bytes used to identify the beginning of a frame of data; Data length: Used to identify the length of a data frame; Valid data: The core part of the data frame, containing the important information that is actually transmitted between buses within the system; if the frame type is a data frame, the data padding length of this area ranges from 0 to 1024 bytes; if the frame type is a remote frame, the data padding length of this area is 0. Checksum: Used for data verification of internal bus transmission frames; the checksum starts at the master / slave identifier and ends at the last byte of the valid data area; Frame end: The frame end is used to mark the end of a frame of data.

[0006] Optionally, the present invention sets the data transmission process of the internal bus communication protocol, including data transmission order and error handling mechanism, determines the priority of the transmission frame according to the frame type and frame identifier in the frame structure of the internal bus communication protocol, and determines the data transmission order according to the priority.

[0007] Optionally, the master device of the present invention uniformly monitors and manages the communication status of all slave devices. When a slave device is detected to have a fault or communication abnormality, the master device takes isolation measures, that is, freezes the identifier of the faulty or communication abnormal slave device when the frame data is generated, so as to achieve isolation with minimal cost.

[0008] Optionally, the master device of the present invention can dynamically adjust the communication rate and data transmission volume according to the system load.

[0009] Optionally, the slave device described in this invention is configured with redundant devices, and when the master device detects a failure in a slave device, it switches to a standby device.

[0010] Optionally, in the system described in this invention, the master device and the slave device operate in different clock domains.

[0011] Beneficial effects: This invention significantly improves the efficiency, stability, and maintainability of communication through an innovative master-slave communication method and an optimized internal bus communication protocol frame structure. It can meet the stringent requirements for data interaction in aerospace missions, such as telemetry data transmission, command execution, and multi-module collaborative control. Attached Figure Description

[0012] 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.

[0013] Figure 1 This is a frame structure diagram of the bus communication protocol in a complex aerospace embedded system. Detailed Implementation

[0014] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0015] It should be noted that, in the absence of conflict, the following embodiments and features can be combined with each other; and, based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0016] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this disclosure, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0017] This embodiment presents a master-slave internal bus communication design method for an aerospace embedded system. The aerospace embedded system includes: a master device responsible for unified scheduling and management of all slave devices; multiple slave devices, each undertaking different tasks; and an internal bus used for data transmission between the master device and the slave devices. The method includes: designing an internal bus communication protocol frame structure and implementing communication between the master and slave devices based on the frame structure. The design of the internal bus communication protocol frame structure includes a master / slave identifier, a frame type, and a frame identifier. The master / slave identifier distinguishes whether the node sending data in the internal bus communication is a master or a slave node. The frame type distinguishes whether the valid data area contains data or not, and is divided into data frames and remote frames. The frame identifier further subdivides data frames and remote frames to determine the frame's purpose. Data frames include: regular command frames without parameters, regular command frames with parameters, telemetry request frames, and data transmission frames. The communication between master and slave devices based on the frame structure includes: command response and data query; Command response method: The master device sends a specific command to the slave device, the slave device receives and parses the command according to the frame format definition, and performs the corresponding operation according to the command requirements; Data query method: The master device sends a data query request command to the slave device as needed. After receiving the data query request command, the slave device sends the relevant information to the master device through the internal bus, so that the master device can keep track of the status of the slave device in a timely manner.

[0018] In this embodiment, the master-slave communication method provides two master-slave interaction modes, which can be flexibly selected according to actual needs: ●Command Response Method The master device sends commands: The master device sends specific commands to the slave device. These commands include information such as source address, destination address, frame type, and frame identifier. For example, the master device sends instructions for the slave device to execute, or commands for the slave device to perform certain data processing.

[0019] Execute and respond from device: Receive commands from device, define and parse commands according to frame format, and perform corresponding operations as required by the commands.

[0020] ●Data Query Methods Master device query: The master device sends a data query request command to the slave device as needed to inquire about the slave device's working status, work count, sensor data, task completion progress and other information.

[0021] Feedback from the device: After receiving a data query request command, the slave device sends the defined count, status, task completion and other relevant information to the master device through the internal bus, so that the master device can keep abreast of the status of the slave device.

[0022] like Figure 1 As shown, the internal bus communication protocol frame structure of this embodiment includes the following fields: ● Frame header: It consists of two parts: a preamble (2B) and a start character (2B). The preamble is fixed at 0x050A and the start character is 0x1122.

[0023] ●Master / Slave Identifier: This identifier is used to distinguish whether the node sending data in the internal bus communication is the master or slave. If the master device is sending data, this value is 0xAAAA; if the slave device is sending data, this value is 0xBBBB.

[0024] ●Master Address and Slave Address: Embedded systems may consist of a "one master, one slave" or "one master, multiple slaves" structure. In a "one master, one slave" structure, the source address is 0x5555 and the destination address is 0xAAAA. In a "one master, multiple slaves" structure, the source address is 0x5555 and the destination addresses are 0x1111, 0x2222, ..., 0xFFFF (numbered sequentially according to the number of slaves).

[0025] ● Frame Type: The frame type is mainly used to distinguish whether there is data or no data in the valid data area, and is divided into data frames and remote frames. Among them, a data frame indicates that there is data in the valid data area, and the frame type of this frame is 0x5555; a remote frame indicates that there is no data in the valid data area, and the frame type of this frame is 0xAAAA.

[0026] ● Frame Identification: This further subdivides data frames and remote frames to determine their purpose. There are many classifications here, detailed in Table 1-3. It mainly includes command frames and data frames.

[0027] ●Data length: Data length represents the total number of data items from the first byte of the frame header to the last byte of the frame tail, in bytes, with a length value of 22+n bytes.

[0028] ●Valid Data: This is the core part of the frame, containing the useful information that is actually transmitted between buses within the system. If the frame type is a data frame, the data padding length in this area ranges from 0 to 1024 bytes; if the frame type is a remote frame, the data padding length in this area is 0.

[0029] ● Checksum: Used for data verification of internal bus transmission frames (the checksum starts at the master / slave identifier and ends at the last byte of the valid data area). The checksum method is 16-bit CRC check.

[0030] ●Frame End: Consists of two parts: a post-completion code (2B) and a terminator (2B). The post-completion code is fixed at 0x0C0A, and the terminator is 0x3344.

[0031] Example: Operation process of an aerospace system based on the master-slave internal bus communication design method for aerospace embedded systems: Initialization: The master device sends initialization commands to all slave devices via the internal bus to configure the operating parameters of each slave device.

[0032] Choose a communication method: Select one or both of the two master-slave interaction methods according to actual needs.

[0033] Establish a communication protocol: Based on the internal bus communication protocol frame format, establish a communication protocol for data interaction between the master device and the slave device; the master device and the slave device complete data interaction through the internal bus communication protocol.

[0034] Error handling: The integrity of data packets is checked through a checksum mechanism. If an error is detected, the affected data packets are retransmitted.

[0035] This embodiment is applicable to aerospace embedded systems that require multi-device collaboration, high real-time decision-making, and anti-interference capabilities, providing reliable technical support for complex missions such as deep space exploration and satellite networking. Two master-slave interaction modes can be dynamically selected according to the actual needs of the project to adapt to different communication scenarios. The internal bus communication protocol supports dynamic adjustment of the field content in the frame structure to adapt to different data transmission requirements.

[0036] Table 1 Data Frame Format Definition

[0037] Table 2 Definition of Valid Data

[0038] Table 3 Remote Frame Format Definitions

[0039] Compared with the prior art, the present invention has the following advantages: High efficiency: This internal bus communication protocol standardizes the data transmission process, including data packet format, transmission order, and error handling mechanisms. This standardization reduces communication errors caused by protocol inconsistencies, improving the reliability and consistency of bus communication within embedded systems. Reliability: (1) Centralized error management: The master device can uniformly monitor and manage the communication status of all slave devices. Once a slave device is detected to have a fault or communication abnormality, the master device can take isolation measures to avoid affecting the operation of the entire system. (2) Flow control and congestion avoidance: The master device can dynamically adjust the communication rate and data transmission volume according to the system load to prevent bus congestion caused by excessive data flow. (3) Support for redundant design: In critical applications, redundant backups can be configured for certain important slave devices. When the master device detects a fault in a slave device, it can seamlessly switch to the backup device to ensure the high reliability of the system.

[0040] Stability: (1) Dynamically allocate resources: The internal bus communication protocol specifies the data transmission format, timing, etc., to ensure that data is accurately transmitted between the master module and the slave module according to the established rules. In this system, the master module and the slave module work in different clock domains. This internal bus communication method can improve the flexibility of the system and facilitate the independent optimization design of each module. When one or more slave modules fail, it will not affect the entire system, thus enhancing the stability of the system. (2) Simplify system design: The internal bus communication protocol specifies that the embedded system adopts a master-slave communication method. Communication requests are initiated and coordinated by the master device, which effectively avoids communication conflicts caused by multiple slave devices competing for bus resources at the same time. (3) Have reliable error detection and correction capabilities: This internal bus communication protocol includes error detection mechanisms such as frame header, frame tail, frame type, frame identifier, and checksum. During data transmission, these mechanisms can detect transmission errors in a timely manner, thereby ensuring the stability and accuracy of data transmission.

[0041] Flexibility: (1) Dynamic resource allocation: Master-slave communication can dynamically allocate bus bandwidth and other resources according to the real-time needs of the system, optimizing system performance. (2) Support for multiple protocol coexistence: In complex embedded systems, different slave modules may need to use different communication protocols. The master device can perform protocol conversion and adaptation based on the internal bus protocol to achieve unified management of multiple protocols. (3) Good scalability: Based on the internal bus communication protocol, system integration is relatively simple and it is easy to add new modules or expand functions. It is only necessary to connect to the bus in accordance with the protocol.

[0042] Real-time performance: The master device can access each slave device sequentially according to a preset priority or round-robin mechanism, ensuring that each device can obtain service within the specified time. Simultaneously, because the master device initiates communication requests, the slave devices' waiting time for response is reduced, thereby lowering the overall system latency.

[0043] Maintainability: Because the communication logic of master-slave communication is concentrated in the master device, debugging and maintenance are relatively simple. Once a problem occurs, the fault can be quickly located by simply checking the communication links between the master device and each slave device.

[0044] This invention is particularly suitable for complex aerospace embedded systems with extremely high requirements for real-time performance, reliability, and efficiency, such as satellite control, multi-payload data interaction systems, and spacecraft navigation.

[0045] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A master-slave internal bus communication design method for an aerospace embedded system, the aerospace embedded system comprising: Main equipment: Responsible for the unified scheduling and management of all slave devices; Multiple slave devices: each performing different tasks; Inside Bus: used for data transmission between a master device and a slave device; characterized in that the method includes: The design of the internal bus communication protocol frame structure includes a master / slave identifier, a frame type, and a frame identifier. The master / slave identifier distinguishes whether the node sending data in the internal bus communication is a master or a slave node. The frame type distinguishes whether the valid data area contains data or not, and is divided into data frames and remote frames. The frame identifier further subdivides data frames and remote frames to determine the frame's purpose. Data frames include: regular command frames without parameters, regular command frames with parameters, telemetry request frames, and data transmission frames. The communication between master and slave devices based on the frame structure includes: command response and data query; Command response method: The master device sends a specific command to the slave device, the slave device receives and parses the command according to the frame format definition, and performs the corresponding operation according to the command requirements; Data query method: The master device sends a data query request command to the slave device as needed. After receiving the data query request command, the slave device sends the relevant information to the master device through the internal bus, so that the master device can keep track of the status of the slave device in a timely manner.

2. The aerospace embedded system master-slave internal bus communication design method according to claim 1, characterized in that, The internal bus communication protocol frame structure also includes the following fields: Frame header: A specific sequence of bytes used to identify the beginning of a frame of data; Data length: Used to identify the length of a data frame; Valid data: The core part of the data frame, containing the important information that is actually transmitted between buses within the system; if the frame type is a data frame, the data padding length of this area ranges from 0 to 1024 bytes; if the frame type is a remote frame, the data padding length of this area is 0. Checksum: Used for data verification of internal bus transmission frames; the checksum starts at the master / slave identifier and ends at the last byte of the valid data area; Frame end: The frame end is used to mark the end of a frame of data.

3. The aerospace embedded system master-slave internal bus communication design method according to claim 2, characterized in that, The data transmission process of the internal bus communication protocol is set, including the data transmission order and error handling mechanism. The priority of the transmission frame is determined according to the frame type and frame identifier in the frame structure of the internal bus communication protocol, and the data transmission order is determined according to the priority.

4. The aerospace embedded system master-slave internal bus communication design method according to claim 2, characterized in that, The master device uniformly monitors and manages the communication status of all slave devices. When a slave device is detected to have a fault or communication abnormality, the master device takes isolation measures, that is, freezes the identifier of the faulty or communication abnormal slave device when frame data is generated.

5. The aerospace embedded system master-slave internal bus communication design method according to claim 2, characterized in that, The master device dynamically adjusts the communication rate and data transmission volume according to the system load.

6. The aerospace embedded system master-slave internal bus communication design method according to claim 2, characterized in that, The slave device is configured with a redundant backup device. When the master device detects a failure in a slave device, it switches to the backup device.

7. The aerospace embedded system master-slave internal bus communication design method according to claim 2, characterized in that, In this system, the master device and the slave device operate in different clock domains.

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