Design and interaction method of communication data frame for aircraft engine distributed control system

Abstract

The present invention discloses a communication data frame design and interaction method for an aircraft engine distributed control system, and the steps are as follows: the host computer performs instruction frame encapsulation on the instructions of the TTP bus node; the central controller node parses and forwards the received host computer instruction frame in packets; the intelligent node unpacks the received central controller node data; the intelligent node feedbacks data frame encapsulation; the central controller parses, encapsulates and sends the intelligent node data frame; the central controller packages all node data frames into a monitoring data frame and sends it to the host computer via Ethernet; the host computer parses and monitors the bus data according to the data frame protocol. The present invention designs a distributed bus communication data frame and interaction method without increasing the TTP hardware monitoring node, realizes the interaction of engine control, instruction and monitoring data under the TTP bus bandwidth, saves equipment cost and equipment installation space, and can greatly reduce the later maintenance cost.

Description

Technical Field

[0001] The invention relates to aviation bus communication technology, in particular to communication data frame design and interaction method of aviation engine distributed control system. Background Art

[0002] In recent years, the distributed numerical control system of aircraft engines has gradually shifted from the research stage to the practical application stage. With the use of distributed intelligent computing nodes, a large amount of control, monitoring and maintenance communication data has been generated. Especially for engines in the pre-research stage, the data generated by the engine and the control system itself also need to be collected and monitored. The centralized architecture of connecting each computing CPU to a monitoring host computer for control, monitoring and maintenance data interaction is no longer suitable for distributed control systems. Therefore, these data must be interacted through the bus.

[0003] As a time-triggered protocol bus, the TTP / C bus has become an important research direction in the application of engine distributed control systems due to its high efficiency, channel redundancy, synchronization and hard real-time characteristics. The common way for the TTP / C bus to interact with the host computer is to hang a dedicated monitoring node on the bus, and the monitoring node interacts with the host computer through a serial port or Ethernet. On the one hand, this method increases the cost due to the introduction of the monitoring node, and on the other hand, it requires installation space at the engine test site, and it is not convenient to disassemble and maintain it later. Therefore, it is necessary to study the use of the master intelligent node on the bus as a bridge to realize the data interaction between the host computer and the intelligent node on the bus, and to realize the transmission of large-capacity control, maintenance and monitoring data under the constraint of bus bandwidth through an interactive method of multiplexing specification communication data frames. Summary of the invention

[0004] Technical solution: The communication data frame design and interaction method of the aircraft engine distributed control system of the present invention comprises the following steps:

[0005] (1) The host computer encapsulates the instruction information of the TTP bus intelligent node into an instruction frame; the node ID is used to distinguish different intelligent nodes in the instruction frame, and the instruction word is used to distinguish the instruction type.

[0006] (2) The central controller node parses and forwards the received host computer command frame in packets; if the central controller does not receive the host computer command frame, it sends the normal control frame data; if the central controller receives the host computer command frame and the command type in the command frame is "program download", the ID and command type in the command frame are updated to the bus status word of the central controller sending frame to notify each bus node to enter the download preparation state; if the command type is not "program download" type, and the ID in the command frame is consistent with the central controller ID, the central controller parses and uses the command frame, otherwise the central controller fills the command data into the data sending buffer of the specified node ID in the command frame to send the command; when the command frame length of a node exceeds the sending data length allocated to the node in the frame, the command frame needs to be sub-packetized, and the total number of sub-packets and the current number of sub-packets are added to each sub-packet frame;

[0007] Among them, the bus status word of the frame sent by the central controller is composed of the node ID and the instruction type, which is used to distinguish the normal control state of the central controller node sending the TTP data frame and the instruction frame control state of the host computer. If the host computer instruction frame is not received, the central controller sends data according to the normal control frame, and the bus status word is set to 0xffff.

[0008] The communication frames between the central controller node and each bus node are sent by broadcast. At the same time, in order to distinguish the data of different nodes for the convenience of later maintenance, the communication frame is partitioned by node data, that is, the starting and ending positions of the node data sent in the frame are controlled by the offset and length in the frame.

[0009] (3) The intelligent node unpacks the received node data from the central controller; if the bus status word of the frame sent by the central controller is a normal control frame, that is, 0xffff, it is parsed according to the normal control protocol; otherwise, if the instruction type of the received bus status word is "program download", the "program download" flag write operation is executed; otherwise, it is determined whether the node ID of the received bus status word is its own ID. If it is not its own ID, normal bus data parsing is performed; if it is its own ID, the instruction frame is parsed and used according to the data length, total number of sub-packets, current number of sub-packets and other information in the instruction frame protocol.

[0010] (4) Intelligent node feedback data frame encapsulation; if the bus status word of the frame sent by the central controller is a normal control frame, that is, 0xffff, the intelligent node feedback data frame is encapsulated according to the normal data protocol frame, and the bus status word of the feedback data frame is a normal data frame, that is, 0xffff;

[0011] Otherwise, if the instruction type of the bus status word of the received central controller node is "program download", the bus status word of the received central controller node is updated to the bus status word of the intelligent node feedback data frame, and the maintenance data is sent in the data area sent by the intelligent node to the central controller according to the "program download" status feedback protocol;

[0012] Otherwise, determine whether it is its own ID based on the node ID in the bus status word of the received central controller node. If it is not its own ID, feedback is performed according to the normal data protocol frame; if it is its own ID, maintenance data is sent according to the feedback protocol of the instruction frame.

[0013] (5) The central controller parses, encapsulates and sends the intelligent node data frames; the central controller packages all node data frames into a monitoring data frame and sends it to the host computer via Ethernet.

[0014] (6) The host computer analyzes and monitors the bus data; after receiving the monitoring data frame, the host computer analyzes the data according to the data frame protocol.

[0015] A computer storage medium stores a computer program, which, when executed by a processor, implements the above-mentioned communication data frame design and interaction method of the aircraft engine distributed control system.

[0016] A computer device comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the above-mentioned communication data frame design and interaction method of the aircraft engine distributed control system is realized.

[0017] Beneficial effects: Compared with the prior art, the present invention has the following advantages: without increasing the TTP hardware monitoring nodes, a distributed bus communication data frame and interaction method are designed to realize the interaction of engine control, instructions and monitoring data under the TTP bus bandwidth, saving equipment costs and equipment installation space, and can greatly reduce the subsequent maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the system hardware architecture diagram;

[0019] Figure 2 It is a data interaction flow chart;

[0020] Figure 3 This is a schematic diagram of the host computer command frame format;

[0021] Figure 4 This is a schematic diagram of the central controller node data analysis and subcontracting process;

[0022] Figure 5Schematic diagram of the normal control (feedback) data frame format sent by the intelligent node;

[0023] Figure 6 Schematic diagram of the packet frame format for sending command frames (command feedback frames) to intelligent nodes;

[0024] Figure 7 This is a schematic diagram of the intelligent node data unpacking process;

[0025] Figure 8 Schematic diagram of the central controller node monitoring data frame format. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0027] System hardware architecture Figure 1 As shown, the host computer 3 and the central controller node 1 are connected via Ethernet 2, and the central controller node 1 and each intelligent node 5 are connected via TTP / C bus 4. Figure 2 As shown, after the system is powered on, the host computer encapsulates and sends the command frame, the central controller node parses, uses or distributes the received command frame, the intelligent node parses and processes the distributed data after receiving it, and encapsulates the feedback data into a frame and sends it to the central controller node, the central controller node encapsulates the intelligent node data frame and sends it to the host computer for parsing and display. The specific steps are as follows:

[0028] S1. Host computer command frame encapsulation and sending

[0029] S1.1. Classify the instruction types of the host computer, set the instruction type "Program download" to "0x01", "Flash maintenance" to "0x02", "Online check" to "0x03", and "Small closed loop" to "0x04";

[0030] S1.2, set the smart node ID, requiring each node ID to be unique and consistent with the hardware ID;

[0031] S1.3. According to Figure 3 Encapsulate the host computer command frame and send it via Ethernet;

[0032] S2, the central controller node parses and forwards the received host computer command frame

[0033] S2.1. Set the central controller node to send frames in different zones. The A and B channels of the smart nodes with the same functions share a sending interval, while the smart nodes with different functions occupy different sending intervals. Figure 5 As shown, a total of 4 node data areas are divided for 8 nodes.

[0034] S2.2, such as Figure 4 As shown in the figure, if the host computer command frame is not received, the central controller node sets the bus status word to 0xffff and fills the normal control frame data into the node data area; otherwise, if the central controller receives the host computer command frame, the ID and command type in the command frame are updated to the bus status word of the frame sent by the central controller. The position of the bus status word in the command frame is shown in the figure. Figure 5 , Figure 6 shown.

[0035] S2.3. If a command frame is received from the host computer and the command type is not "program download" type, and the ID in the command frame is consistent with the central controller ID, the central controller parses and uses the command frame.

[0036] S2.4, if the ID in the instruction frame is inconsistent with the central controller ID, the instruction frame is filled into the node data area of ​​the corresponding node ID according to the node ID number in the instruction frame. If the instruction frame length exceeds the allocated length of the node data area, it is sub-packeted: the first two bytes of the node data area of ​​each packet are filled with the total number of node packets and the current number of node packets, and the remaining node data area is filled with instruction frame information, as shown in the following figure. Figure 6 shown.

[0037] Among them: total number of packets = [command frame byte length / (node ​​data area byte length-2)], the algorithm adopts the rounding algorithm; the current number of packets is increased by 1 each time the sub-packet data is sent.

[0038] S2.5. The central control node sends data frames in a broadcast mode, and all intelligent nodes on the bus can receive the data frames.

[0039] S3, the intelligent node unpacks the received central controller node data

[0040] S3.1, if Figure 7 As shown, if the bus status word of the frame sent by the central controller received by the intelligent node is a normal control frame, that is, 0xffff, it is parsed according to the normal control protocol;

[0041] S3.2, otherwise if the instruction type of the received bus status word is "program download", the "program download" flag write operation is executed;

[0042] S3.3, otherwise determine whether the node ID of the received bus status word is its own ID. If it is not its own ID, perform normal bus data parsing; if it is its own ID, parse and use the instruction frame according to the header, data length, total number of subpackets, current number of subpackets and other information in the instruction frame protocol.

[0043] S4, intelligent node feedback data frame encapsulation and transmission;

[0044] S4.1. If the bus status word of the frame sent by the central controller is a normal control frame, that is, 0xffff, the intelligent node feedback data frame is encapsulated according to the normal data protocol frame, and the bus status word of the feedback data frame is a normal data frame, that is, 0xffff;

[0045] S4.2, otherwise, if the instruction type of the bus status word of the received central controller node is "program download", the bus status word of the received central controller node is updated to the bus status word of the intelligent node feedback data frame, and the maintenance data is sent in the data area sent by the intelligent node to the central controller according to the "program download" instruction frame feedback frame protocol;

[0046] S4.3, otherwise, according to the node ID in the bus status word of the received central controller node, determine whether it is its own ID. If it is not its own ID, feedback is performed according to the normal feedback data protocol; if it is its own ID, maintenance data is sent according to the feedback protocol of the instruction frame;

[0047] When the length of the command feedback frame protocol exceeds the length of the data area allocated by the intelligent node for the feedback target node, it is necessary to perform subpacket processing. The subpacket processing method is shown in S2.4. The format of the intelligent node feedback data frame protocol is shown in Figure 5 ; Intelligent node command feedback frame packet format see Figure 6 .

[0048] S5. The central controller node analyzes, uses, encapsulates and sends the intelligent node data frame

[0049] After receiving the node data, the central controller analyzes the node data and uses the feedback information to control the engine. On the other hand, it packages all the node data frames into a monitoring data frame and sends it to the host computer via Ethernet. The specific frame format is shown in Figure 8 .

[0050] S6. The host computer analyzes and monitors the received central controller bus data

[0051] After receiving the monitoring data frame, the host computer adapts different protocols for each node according to the node ID and instruction type in the bus status word of the feedback data frame of each node for parsing and display.

Claims

1. The design and interaction method of communication data frame of aircraft engine distributed control system includes the following steps: (1) The host computer encapsulates the command information of the TTP bus intelligent node into a command frame; (2) The central controller node parses and forwards the received host computer command frame in packets; if the central controller does not receive the host computer command frame, it sends the normal control frame data; if the central controller receives the host computer command frame and the command type in the command frame is "program download", the ID and command type in the command frame are updated to the bus status word of the central controller sending frame to notify each bus node to enter the download preparation state; if the command type is not "program download" type, and the ID in the command frame is consistent with the central controller ID, the central controller parses and uses the command frame, otherwise the central controller fills the command data into the data sending buffer of the specified node ID in the command frame to send the command; when the command frame length of a node exceeds the sending data length allocated to the node in the frame, the command frame needs to be sub-packetized, and the total number of sub-packet frames and the current sub-packet frame sequence number information of the command frame are added to each sub-packet frame; (3) The intelligent node unpacks the received node data from the central controller; if the bus status word of the frame sent by the central controller is a normal control frame, that is, 0xffff, it is parsed according to the normal control protocol; otherwise, if the instruction type of the received bus status word is "program download", the "program download" flag write operation is performed; otherwise, it is determined whether the node ID of the received bus status word is its own ID. If it is not its own ID, normal bus data parsing is performed; if it is its own ID, the instruction frame is parsed and used according to the data length, total number of sub-packet frames and current sub-packet frame sequence number information in the instruction frame protocol; (4) Encapsulation of the intelligent node feedback data frame; if the bus status word of the frame sent by the central controller is a normal control frame, the intelligent node feedback data frame is encapsulated according to the normal data protocol frame, and the bus status word of the feedback data frame is a normal data frame; Otherwise, if the instruction type of the bus status word of the received central controller node is "program download", the bus status word of the received central controller node is updated to the bus status word of the intelligent node feedback data frame, and the maintenance data is sent in the data area sent by the intelligent node to the central controller according to the "program download" status feedback protocol; Otherwise, according to the node ID in the bus status word of the received central controller node, determine whether it is its own ID. If it is not its own ID, feedback is performed according to the normal data protocol frame; if it is its own ID, maintenance data is sent according to the feedback protocol of the instruction frame; (5) Parsing, encapsulating and sending data frames of intelligent nodes by the central controller; The central controller packages all node data frames into a monitoring data frame and sends it to the host computer via Ethernet; (6) The host computer analyzes and monitors the bus data; after receiving the monitoring data frame, the host computer analyzes the data according to the data frame protocol.

2. The communication data frame design and interaction method of the aircraft engine distributed control system according to claim 1 is characterized in that: In the instruction frame described in step (1), different intelligent nodes are distinguished by node ID, and instruction type is distinguished by instruction word.

3. The communication data frame design and interaction method of the aircraft engine distributed control system according to claim 1 is characterized in that: The bus status word of the frame sent by the central controller described in step (2) is composed of the node ID and the instruction type, which is used to distinguish the normal control state of the central controller node sending the TTP data frame and the instruction frame control state of the host computer. If the host computer instruction frame is not received, the central controller sends data according to the normal control frame, and the bus status word is set to 0xffff.

4. The communication data frame design and interaction method of the aircraft engine distributed control system according to claim 1 is characterized in that: In the step (2), the communication frames between the central controller node and each bus node are sent by broadcasting.

5. The communication data frame design and interaction method of the aircraft engine distributed control system according to claim 1 is characterized in that: In the step (2), node data partitioning is performed on the communication frame, that is, the starting position and the ending position of the node data sent in the frame are controlled by the offset and the length in the frame.

6. A computer storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the communication data frame design and interaction method of the aircraft engine distributed control system as described in any one of claims 1 to 5 is implemented.

7. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, it implements the aircraft engine distributed control system communication data frame design and interaction method as described in any one of claims 1-5.

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