Task Scheduling Algorithm In Flight Control System And More Reliability Control Research

Embedded technology continues to mature, widely used in many fields, such assmart appliances, industrial control, aerospace, national defense construction. Amongthem, in some areas of aerospace, industrial control, real-time embedded systems withhigh demands. For example, the system in a timely manner and quickly received datacorresponding to the processing and sometimes must be based on the results issued onthe system or equipment under their control and the corresponding control command. Ifcertain tasks in the system before the prescribed deadline has not yet been implemented,it may cause some of the imagery is not sometimes disastrous consequences. Therefore,we must be in a specific application, select the appropriate scheduling algorithm toguarantee high real-time and high reliability of the entire system.Rate monotonic (RM) scheduling algorithm is a classic static priority schedulingalgorithm. If a task set under the RM algorithm is scheduling. Then use the RMalgorithm, will be able to guarantee real-time implementation of the mandate of this taskset. Therefore, according to the background characteristics of the project, chose to usethe RM algorithm. For real-time scheduling algorithm, the task set schedulability test isa very important issue. Detailed description of the task set schedulability under the RMalgorithm to determine. And in the RM algorithm implementation and performanceanalysis.RM algorithm is priority-based preemptive scheduling. Simple preemptive priorityscheduling algorithm, the principle is simple, easy to implement, to ensure a strongreal-time task set. However, prone to high-priority task exception or system failure,which led to high-priority task timeout consume processor resources to low-priority taskcan not get the processor resources and starve, and even lead to the collapse of thesystem.The round-robin scheduling algorithm is a classic scheduling algorithms used intime-sharing system. Assigned a time slice for each task, each task in the exclusiveprocessor within the allocated time slice. This a time of isolation between each task.Useof this feature in the round-robin scheduling algorithm, this dissertation constructed a combination of preemptive priority scheduling and round-robin scheduling advantagesof the two scheduling algorithms, the system abnormalities caused by impact of controlwithin a small range, it is neitheraffect the whole system of real-time, but also improvethe reliability of the system.Construction and Analysis of the theory of this two scheduling algorithms in theμC/OS-II operating system to implement, and performance analysis.