Research And Application Of Task Scheduling Method Based On Embedded Real Time Operating System

The embedded system has such a common characteristic that they have strictlytime constraint. As the embedded system is getting more complicated and usually inuncertain circumstances, task schedule is attracting wide spread attention.Firstly, the thesis introduces the classical scheduling policy in RTOS andanalyzes the limitation of all kinds task scheduling algorithms. Secondly, in theviewpoint of real-time system's uncertainty and unpredictability ,mixed real-timetask is analyzed and its scheduling algorithm and frame and model is proposed .Inthe study of task feedback schedule, detail analysis in PI controller architecture andFC-U,FC-M and FC-UM is given on the basis of Chenyang Lu and JohnA.Stankovic's feedback control real-time scheduling theory. And also the algorithms'metrics and disadvantages are concluded. When it comes to the control and scheduleco-design problem, model of real-time control and scheduling co-design and Qocscheduling policy are proposed by using flexible spring algorithm dealing withdisturbance arrival with the evaluation foundation of Qoc.Finally, in the field offeedback control and mixed real-time scheduling ,the tank model based on feedbackschedule and its controller algorithm are presented by tuning soft real-time tasks loadwith access and Qos regulator when guaranteeing hard real-time tasks' loadbandwidth in the frame of feedback control mixed real-time task scheduling .Thesimulation results proves its feasibility.TheμC/OS-Ⅱsystem is ported on TMS320LF2407A hardware platform afterstudying the task manage and kernel portion ofμC/OS-Ⅱ. On the basis of itsscheduling polity extensional study, its kernel is revised and tasks and softwarearchitecture is designed by porting feedback control and mixed task schedulingalgorithm. The result validates its effectiveness in improving robustness of real-timesystem.