A heterogeneous bus cross communication method

Abstract

A heterogeneous bus cross-communication method, belonging to the field of satellite onboard bus communication, includes: determining whether to use two types of buses based on the data volume and transmission rate of each single machine; setting up a double buffer to perform cross-collection on the two types of buses to determine whether there is data interaction between the two types of buses; cross-arranging single machines with data interaction requirements; polling single machines on bus A, and polling single machines on bus B within a waiting time T to determine whether there is data to be exchanged in buffer A'; collecting data from single machines on bus B while transmitting the data to be exchanged; cross-polling all single machines on the two types of buses in sequence, and packaging the data in the buffer for downloading. The present invention adjusts the control strategy of the onboard computer for the two types of buses to achieve rapid cross-collection of single machine data across the buses within the waiting time, shortening the information collection cycle; integrating telemetry collection with data upload tasks, simplifying the interaction process between different single machines on the two types of buses, and improving the efficiency of uploaded data transmission.

Description

Technical Field

[0001] The present invention belongs to the technical field of satellite onboard bus communication, and in particular relates to a heterogeneous bus cross-communication method. Background Art

[0002] Satellite onboard computers usually use a single communication bus to complete the routine telemetry collection tasks of each unit. The communication rate of the bus is fixed, and all units are connected to the same bus. When two types of communication buses are introduced, the polling collection strategy of the satellite onboard computer is usually to complete the telemetry collection tasks of each communication bus in turn, and the data interaction between the two buses will not be interspersed. The data blocks uploaded from the ground to certain units on the satellite through the measurement and control station usually complete the entire upload process in the order of transmission from the measurement and control unit, the onboard computer, and the receiving unit. At the same time, this upload process is an independent task and is not integrated with the routine telemetry collection tasks.

[0003] As satellites become increasingly complex in orbit, the number of individual units on board and their technical status continue to increase. Satellites need to introduce and support multiple communication buses, and therefore need to optimize the interaction logic between different communication buses for telemetry acquisition tasks. When multiple communication buses coexist, units on different buses will need to frequently exchange data. Currently, the following problems exist when two different communication buses are used on board:

[0004] (1) In completing the telemetry acquisition task of the entire satellite, if there are two types of heterogeneous communication buses on the satellite, a certain number of single machines will be deployed on each communication bus. The acquisition strategy of the on-board computer is usually to complete the polling and acquisition of all single machines on a single bus, and then continue to poll and acquire the single machines on another bus; and after receiving the poll, the single machine has a certain waiting time for response. There is usually no operation during the waiting time for response. The superposition of the waiting time for response of multiple single machines will cause a waste of on-board computer time.

[0005] (2) In the whole-satellite telemetry acquisition task and the ground data injection task, the onboard computer usually processes the two tasks separately. The injection data needs to be stored in the memory of the measurement and control unit first, and then transferred to the memory of the target receiving unit by the onboard computer. The injection data can be obtained during the whole-satellite telemetry acquisition task. It is not considered to complete the transmission of the injection data during the telemetry acquisition task, which brings about a certain degree of delay in the use of the injection data. Summary of the Invention

[0006] In response to the shortcomings of the existing technology, the present invention provides a heterogeneous bus cross-communication method. This method adjusts the satellite telemetry acquisition strategy when two types of heterogeneous communication buses coexist. While the low-speed bus is waiting for a single machine's response data, telemetry data is collected from a single machine on the other high-speed bus, thereby improving onboard computer time utilization. For satellite telemetry acquisition tasks and ground data injection tasks, the method transfers interactive data (i.e., injection data) on different communication buses to the target receiving machine while the two types of heterogeneous communication buses cross-execute the satellite telemetry acquisition task. This avoids off-site storage of injection data and improves injection data execution efficiency.

[0007] The technical solutions adopted by the present invention to solve the technical problems are as follows:

[0008] The present invention provides a heterogeneous bus cross communication method, comprising the following steps:

[0009] Step S1: In combination with the telemetry mission of the entire satellite, according to the amount of data generated by each single machine on the satellite and the different transmission rate requirements, determine whether to use two types of heterogeneous communication buses. If so, proceed to step S2; if not, proceed to step S6;

[0010] Step S2: The onboard computer uses two different types of heterogeneous communication buses with different transmission rates. The low-transmission-rate bus is bus A, corresponding to buffer A'; the high-transmission-rate bus is bus B, corresponding to buffer B'. Based on different technical status and data requirements, each stand-alone computer is assigned to a different heterogeneous communication bus. The onboard computer performs cross-data collection on the stand-alone computers on bus A and bus B, and determines whether the stand-alone computers on bus A and bus B have data exchange requirements. If so, the process proceeds to step S3; if not, the process proceeds to step S6.

[0011] Step S3: When a single machine M on bus A and a single machine N on bus B need to exchange data, the acquisition sequences of single machine M and single machine N are connected in sequence during cross-collection. After polling single machine M, single machine N is polled across buses.

[0012] Step S4: After polling the stand-alone machine M, the onboard computer polls the stand-alone machine N within the waiting response time T, and determines whether there is data to be exchanged in the buffer A'. If so, the process proceeds to step S5; if not, the process proceeds to step S6.

[0013] Step S5: sending the data to be exchanged in the buffer A' when receiving the response data from the stand-alone N, and at the same time putting the response data from the stand-alone N into the buffer B';

[0014] Step S6: The onboard computer cross-polls all the units on the A bus and the B bus in the acquisition order, packages the data in the buffers A' and B' into the whole-satellite downlink telemetry frame, and then transmits it to the ground.

[0015] As a preferred implementation, in step S1, the amount of data generated by each single machine is rapidly varying and slowly varying telemetry data.

[0016] As a preferred implementation, in step S1, determining whether to adopt two types of heterogeneous communication buses refers to whether it is necessary to simultaneously adopt two different types of heterogeneous communication buses to complete the onboard platform telemetry acquisition task.

[0017] As a preferred implementation, the A bus adopts a CAN bus or a 1553B bus.

[0018] As a more preferred implementation, the baud rate of the CAN bus is 500 Kbps.

[0019] As a preferred implementation, the B bus adopts a high-speed SPI bus or an RS422 bus.

[0020] As a more preferred implementation, the transmission rate of the SPI bus is 8 Mbps.

[0021] As a preferred implementation, in step S2, a single machine with a relatively mature technical status, low on-orbit data volume and low transmission rate is allocated to bus A.

[0022] As a preferred implementation, in step S2, a single machine with a relatively new technical status, a high amount of on-orbit data and a high transmission rate is allocated to bus B.

[0023] As a preferred implementation, the waiting response time T ranges from 0.5 ms to 2 ms.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. Under the operating condition that the entire satellite adopts two types of heterogeneous communication buses, the present invention analyzes the data volume and transmission rate of each single machine, reasonably sets the waiting time for the single machine to respond to data, and then adopts a cross-polling strategy for the single machines on the two communication buses. This avoids the idle and wasted waiting time of multiple single machines for responses, thereby improving the on-board computer time utilization and telemetry acquisition efficiency.

[0026] 2. Based on the cross-collection of two types of heterogeneous communication buses, the present invention integrates the design of the whole-satellite telemetry collection task and the ground data injection task, and completes the cross-bus transmission of the injection data to be transmitted in the two tasks in the whole-satellite telemetry collection task, avoiding multiple storage and transfer of the injection data, thereby improving the integration of software tasks and the timeliness of the injection data. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a typical working mode of cross-bus communication in a heterogeneous bus cross-communication method provided by the present invention.

[0028] Figure 2 The present invention provides a flow chart of a heterogeneous bus cross communication method. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below with reference to the accompanying drawings.

[0030] In the present invention, the typical working mode of cross bus communication is as follows Figure 1 Among them, the onboard computer exchanges data with the external single machine through the communication interface, and sets independent buffers for the A bus and the B bus respectively. Figure 1 Buffer A' and buffer B' in the buffer; the usual polling acquisition strategy is to individually poll and acquire all units on a single bus and then switch to another bus. For example, the onboard computer first polls units 1 to 3 on bus A, and then polls units 4 to 6 on bus B; after crossing bus A and bus B, bus cross communication is performed. The onboard computer cross-polls the units on bus A and bus B, and completes the transmission of the injected data during the polling process. For example, the onboard computer first polls unit 1 on bus A, and then polls unit 4 on bus B, and cross-polls in the order of unit 1 on bus A, unit 4 on bus B, unit 2 on bus A, unit 5 on bus B, unit 3 on bus A, and unit 6 on bus B; finally, after polling all units, they are packaged into a whole-satellite telemetry frame and transmitted to the measurement and control equipment.

[0031] A heterogeneous bus cross-communication method of the present invention sets the number of communication buses and polling collection strategies after analyzing the data volume and transmission rate requirements of each single machine on the satellite. For two types of heterogeneous communication buses, cross-communication is used to complete telemetry data collection and timely transmission of injection data.

[0032] See also Figure 2 To illustrate, a heterogeneous bus cross communication method of the present invention has the following specific implementation process:

[0033] Step S1: In combination with the telemetry task of the entire satellite, analyze the amount of fast-changing and slowly-changing telemetry data generated by each single machine on the satellite, and perform the whole-satellite machine time analysis according to the bus communication transmission rate commonly used by the satellite platform (generally 500Kbps). According to the amount of data generated by each single machine on the satellite and the different requirements for transmission rate, determine whether it is necessary to add a heterogeneous communication bus in the telemetry data collection process of the satellite platform, that is, whether it is necessary to use two different types of heterogeneous communication buses at the same time to complete the telemetry collection task of the satellite platform. If so, proceed to step S2; if not, proceed to step S6.

[0034] Step S2: setting a double buffer to perform cross-collection on the two types of buses, and determining whether there is a need for data exchange between the two types of buses;

[0035] The onboard computer uses two different types of heterogeneous communication buses with different transmission rates to complete the onboard platform telemetry acquisition tasks. Among them, the low transmission rate bus is bus A, which adopts commonly used buses on board, such as CAN bus and 1553B bus; the high transmission rate bus is bus B, which adopts high-speed SPI bus and RS422 bus, and the transmission rate of SPI bus is 8Mbps. These two different types of heterogeneous communication buses with different transmission rates correspond to two different receive buffers, bus A corresponds to buffer A', and bus B corresponds to buffer B'.

[0036] Based on their technical status and data requirements, each unit is assigned to a different heterogeneous communication bus. Units with relatively mature technology, low on-orbit data volumes, and low transmission rates are assigned to Bus A, while units with relatively new technology, high on-orbit data volumes and transmission rates are assigned to Bus B. To improve the overall acquisition rate under heterogeneous communication buses, the onboard computer performs cross-collection on units on Buses A and B. It also determines whether units on Buses A and B require data exchange. If so, the process proceeds to Step S3; if not, the process proceeds to Step S6.

[0037] Specifically, bus A can utilize a CAN bus with a baud rate of 500 Kbps, while bus B can utilize an SPI bus with a transmission rate of 8 Mbps. Based on their technical status and data requirements, individual devices are assigned to the CAN and SPI buses. Devices with relatively mature technology and low telemetry data volume and transmission rate requirements, such as those for power supply, attitude control, measurement and control, and intersatellite operations, are assigned to the conventional CAN bus. Devices with relatively new technology and high telemetry data volume and transmission rate requirements, such as those for real-time processing and AI, are assigned to the SPI bus. To improve the overall acquisition rate under the coexistence of the CAN and SPI buses, cross-acquisition is performed on the devices on the CAN and SPI buses. This involves acquiring data from the CAN power device, followed by the SPI real-time processing device, and then the CAN attitude control device. Furthermore, a determination is made as to whether the devices on the CAN and SPI buses require data exchange. If so, the process proceeds to step S3; if not, the process proceeds to step S6.

[0038] Step S3: Cross-arrange the single machines that have data interaction requirements;

[0039] There is a need for data interaction between the single machine M on the A bus and the single machine N on the B bus. When the onboard computer performs cross-collection on the single machines on the A bus and the B bus, the collection sequence of the single machine M and the single machine N is connected, that is, after polling the single machine M, the single machine N is polled across the bus.

[0040] Specifically, bus A can adopt a CAN bus with a baud rate of 500Kbps, and bus B can adopt an SPI bus with a transmission rate of 8Mbps; the single machine M is an intersatellite single machine, and the single machine N is a real-time processing single machine; the intersatellite single machine on the CAN bus can receive uploaded data from the ground, and the real-time processing single machine on the SPI bus has the need to replace software on orbit and needs to receive uploaded data frequently, that is, there is a need for data exchange between the real-time processing single machine on the SPI bus and the intersatellite single machine on the CAN bus; therefore, when the onboard computer cross-collects the single machines on the CAN bus and the SPI bus, the collection order of the intersatellite single machine and the real-time processing single machine is connected, that is, after polling the intersatellite single machine, the real-time processing single machine is polled across the bus.

[0041] Step S4: poll the A bus stand-alone machine, poll the B bus stand-alone machine within the waiting response time T, and determine whether there is data to be exchanged in the buffer A';

[0042] After polling the stand-alone machine M on the A bus, the onboard computer polls the stand-alone machine N on the B bus within the waiting response time T, and determines whether there is data to be exchanged in the buffer A'. If so, it goes to step S5; if not, it goes to step S6.

[0043] Specifically, bus A can be a CAN bus with a baud rate of 500 Kbps, and bus B can be an SPI bus with a transmission rate of 8 Mbps. Machine M is an intersatellite machine, and machine N is a real-time processing machine. When the onboard computer polls the intersatellite machine on the CAN bus, it can collect telemetry data from the intersatellite machine and ground-injected data received by the machine. After polling the intersatellite machine, the onboard computer polls the real-time processing machine on the SPI bus within a waiting time T (0.5 ms to 2 ms) (each machine cross-communicating on the SPI bus saves one waiting time T). The computer then determines whether there is data to be exchanged (the above data) received by the intersatellite machine in buffer A'. If so, the process proceeds to step S5; if not, the process proceeds to step S6.

[0044] Step S5: while collecting the data of the single machine on bus B, transmit the data to be exchanged;

[0045] The latest data to be exchanged in the buffer A' corresponding to the A bus is sent out when the response data of the single machine N on the B bus is received, and the response data of the single machine N is put into the buffer B' corresponding to the B bus.

[0046] Specifically, bus A can adopt a CAN bus with a baud rate of 500Kbps, and bus B can adopt an SPI bus with a transmission rate of 8Mbps; the single machine M is an intersatellite single machine, and the single machine N is a real-time processing single machine; when the shortest waiting response time T (T=0.5ms), according to the 8Mbps transmission rate of the SPI bus, the amount of data that can be transmitted within 0.5ms is 500B, which can cover the telemetry package of the real-time processing single machine on the SPI bus and the data injected once on the ground; the SPI bus works in a simultaneous data transmission and reception mode, so when the onboard computer receives the response data (within 500B) from the real-time processing single machine on the SPI bus, it can synchronously send the latest data to be exchanged (within 500B) in the buffer A' corresponding to the CAN bus to the real-time processing single machine, and then put the response data of the real-time processing single machine into the buffer B' corresponding to the SPI bus.

[0047] Step S6: The onboard computer cross-polls all the units on the A bus and the B bus according to the predetermined acquisition sequence, packages the data in the buffers A' and B' into the satellite downlink telemetry frame, and then transmits it to the ground.

[0048] The present invention provides a heterogeneous bus cross-communication method. Aiming at the working condition that the satellite onboard platform adopts two types of heterogeneous communication buses to complete the telemetry task of the whole satellite, the corresponding relationship between each lower computer and the communication bus is adjusted according to the different functional requirements of each lower computer, that is, a single computer. Then, by adjusting the control strategy of the onboard host for the two types of heterogeneous communication buses, the cross-bus lower computer data is quickly cross-collected within the waiting response time, the information collection cycle is shortened, and the telemetry collection task and the upload data task can be integrated at the same time, simplifying the interaction process between different lower computers on the two types of heterogeneous communication buses, improving the upload data transmission efficiency, and facilitating the improvement of the overall performance of the satellite.

[0049] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A heterogeneous bus cross communication method, characterized in that: The following steps are involved: Step S1: In combination with the telemetry mission of the entire satellite, according to the amount of data generated by each single machine on the satellite and the different transmission rate requirements, determine whether to use two types of heterogeneous communication buses. If so, proceed to step S2; if not, proceed to step S6; Step S2: The onboard computer uses two different types of heterogeneous communication buses with different transmission rates. The low-transmission-rate bus is bus A, corresponding to buffer A'; the high-transmission-rate bus is bus B, corresponding to buffer B'. Based on different technical status and data requirements, each stand-alone computer is assigned to a different heterogeneous communication bus. The onboard computer performs cross-data collection on the stand-alone computers on bus A and bus B, and determines whether the stand-alone computers on bus A and bus B have data exchange requirements. If so, the process proceeds to step S3; if not, the process proceeds to step S6. Step S3: When a single machine M on bus A and a single machine N on bus B need to exchange data, the acquisition sequences of single machine M and single machine N are connected in sequence during cross-collection. After polling single machine M, single machine N is polled across buses. Step S4: After polling the stand-alone machine M, the onboard computer polls the stand-alone machine N within the waiting response time T, and determines whether there is data to be exchanged in the buffer A'. If so, the process proceeds to step S5; if not, the process proceeds to step S6. Step S5: sending the data to be exchanged in the buffer A' when receiving the response data from the stand-alone N, and at the same time putting the response data from the stand-alone N into the buffer B'; Step S6: The onboard computer cross-polls all the units on the A bus and the B bus in the acquisition order, packages the data in the buffers A' and B' into the whole-satellite downlink telemetry frame, and then transmits it to the ground.

2. A heterogeneous bus cross communication method according to claim 1, characterized in that: In step S1, the data volume generated by each single machine is the rapidly varying and slowly varying telemetry data volume.

3. The heterogeneous bus cross communication method according to claim 1, characterized in that: In step S1, determining whether to adopt two types of heterogeneous communication buses refers to whether it is necessary to adopt two different types of heterogeneous communication buses at the same time to complete the telemetry acquisition task of the onboard platform.

4. The heterogeneous bus cross communication method according to claim 1, characterized in that: The A bus adopts CAN bus or 1553B bus.

5. A heterogeneous bus cross communication method according to claim 4, characterized in that: The baud rate of the CAN bus is 500 Kbps.

6. The heterogeneous bus cross communication method according to claim 1, characterized in that: The B bus adopts a high-speed SPI bus or an RS422 bus.

7. A heterogeneous bus cross communication method according to claim 6, characterized in that: The transmission rate of the SPI bus is 8 Mbps.

8. The heterogeneous bus cross communication method according to claim 1, characterized in that: In step S2, single machines with relatively mature technical status, low on-orbit data volume and transmission rate are allocated to bus A.

9. The heterogeneous bus cross communication method according to claim 1, characterized in that: In step S2, the single machines with relatively new technical status, high on-orbit data volume and high transmission rate are allocated to bus B.

10. The heterogeneous bus cross communication method according to claim 1, characterized in that: The waiting response time T ranges from 0.5 ms to 2 ms.

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