Real-time Scheduling Technology And FPGA Implementation Of Multi-source Heterogeneous High-speed Data On Board

Real-time scheduling refers to the process of integrating data from multiple sources into a single channel and transmitting it to the receiving device through a physical channel.It is a key link in space data transmission such as satellite remote sensing and deep space exploration.With the increasing demand for spatial data acquisition and increasingly diverse detection methods,a variety of heterogeneous and high-speed payload data streams need to be transmitted through limited data transmission channels,and a real-time on-board scheduling technology for multi-source heterogeneous high-speed data is urgently needed to ensure the efficiency and reliability of the data transmission process.The research on real-time scheduling technology is faced with three major problems: expression ability of priority,system-constrained scheduling,and reliable protection of SEU.On the basis of deep analysis on the application characteristics of real-time scheduling of satellite data,this paper has successively carried out research on application in three aspects: virtual channel scheduling algorithm,real-time scheduling system,protection and verification of single event upset.First,based on the multi-source heterogeneous characteristics of the source and the dynamic characteristics of the rate,a dynamic scheduling algorithm with adaptive rate is proposed based on priority competition mechanism,in which the inherent weight,latency of the data frame,and the rate of the virtual channel are comprehensively evaluated.It veritably expresses the transmission requirements of the data frame and the virtual channel in real time.Compared with the traditional scheduling algorithm,it has obtained better delay statistics in various kinds of typical applications.Secondly,under the constraints of the limited resources and limited bandwidth of the spaceborne system,a reliable and efficient data frame protocol is designed,and a system architecture of "receiving,scheduling,and storage output" is proposed.Through the optimization of the cache,sorting of priority,handshake communication and so on,the design eases the contradiction among resources,bandwidth and scheduling capability,and the real-time scheduling system is implemented based on FPGA,with working clock up to 127 MHz.Finally,in view of the problem that the spaceborne system is susceptible to single event upset when on orbit,a single event upset protection system under resource constraints is established,and a trigger-based single event upset simulation method and simulation verification system are proposed.It is made possible to test the SEU fault tolerance of the protection system comprehensively and efficiently,and shorten the design and verification period of the protection system.Simulation analysis and example verification show that,the on-chip resource utilization rate of the real-time on-board scheduling system for multi-source heterogeneous high-speed data realized in this paper is below 33%,and the available bandwidth utilization rate of the physical channel to transmit the payload data is as high as up to 99.39%.In addition,it shows good statistical delay properties and flexibility when it is applied actually to the transmission task of code stream data in a satellite system,and it also greatly improves the fault-tolerant ability of single event upset,meets the task requirements,and verifies the effectiveness of the results of this paper.