Communication method of application layer of FlexRay bus for small satellite

Abstract

The invention relates to a communication method of an application layer of a FlexRay bus for a small satellite. Transmission information of an electronic system on the satellite is divided into two types firstly, one type of the information belongs to information transmitted in a normal mode of the electronic system on the satellite and is transmitted through a static section of the FlexRay bus, and the other type of the information belongs to information which is transmitted in an abnormal model of the electronic system on the satellite and is transmitted through a dynamic section of the FlexRay bus. According to the amount of information flow of the electronic system on the satellite, speed of the FlexRay bus, the size of a time slot in the static section, the size of a time slot in the dynamic section, and distribution of the time slots are reasonably formulated, and then a time dispatch list of the FlexRay bus is formulated to provide basis for authoring satellite-borne FlexRay bus software. The communication method resolves the problem of communication interaction of satellite application of the FlexRay bus, software programming of each node of the FlexRay bus has rules to follow, and the using rate of transmission of the FlexRay bus is also improved.

Description

technical field [0001] The invention relates to a communication method of a FlexRay (flexible ray) bus application layer, which belongs to the field of computer communication. Background technique [0002] Modern small satellites use bus technology for on-board information transmission. Through the bus, the on-board computer of the satellite can manage and control the satellite efficiently and reliably, so as to realize the predetermined functions and task requirements. In the past, my country's satellite network transmission mostly used 1553B and CAN buses. These two buses are completely event-triggered buses. All activities in the event-triggered bus network are caused by the occurrence of events. When transmitting data to the bus, all nodes in the network may be the next sender, resulting in network event conflicts, network congestion, frame loss, delay and other problems, network real-time performance, reliability, and security are reduced, affecting Network communication...

AI Technical Summary

Problems solved by technology

However, the FlexRay bus protocol does not make detailed regulations on the application layer, but only stipulates the length of the communication cycle, the maximum effective number of transmission bits of each time slot and other parameters, and the size of the application layer time slot, configuration of the time slot, and information interaction The cycle is not specified in detail

[0010] Although there has been preliminary research on the FlexRay application layer in the automotive field, due to the diversity of transmission information of satellite applications, high reliability of transmission, and limited resources on the satellite, it is not completely suitable for satellite applications. There are two main reasons. One, one is in the automotive field, the FlexRay bus is mainly used in the wire control system, the control information is small and single, so in the automotive field, the information interaction cycle of the FlexRay bus is the bus cycle, and in the satellite application field, the FlexRay bus not only has to bear The transmission of control information on the star is also responsible for the transmission of management information, so the amount of information transmitted on the star is large and diverse. A single bus cycle cannot meet the needs of the star. It is necessary to reconfigure the time slots on the FlexRay bus. Carry out cycle extension; another reason is that only the static segment of the FlexRay bus is used in the automotive field, and in the satellite field, due to unexpected events such as the above-mentioned information and failure modes, it is necessary to transmit information in time, so the static segment cannot only be considered, and the static segment needs to be considered. Use dynamic segments to ensure timely delivery of information

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