摘要
由于数控系统的动态特性,其运行过程中可能会发生处理器过载现象.开环的调度算法无法在处理器过载时仍然保持系统的稳定,从而对加工精度造成影响.为了提高数控系统的稳定性,本文针对数控系统的混合任务集提出一个闭环的反馈调度模型.并通过实验对模型的有效性进行了验证.实验结果表明,该调度模型能够提高数控系统的稳定性.
Because there is some sporadic tasks in the CNC system and the CNC system is sensitive to data,the CPU may overload aperiodic.In the case,some real-time task would break their deadline,and decrease the quality of machining.For increasing the steadiness of CNC system,we advance a dynamical scheduling model that is close loop.The model is PES-ACNR（Priority-based Elastic Scheduling-Admission control of Non-Real-time tasks）.It aims at the mixed tasks set.PES-ACNR can adjust the period of soft real-time task,according to the CPU utilization and the lost rate.And it can ensure the CPU utilization below the reference value.For decreasing the mount of disturbance to hard real-time tasks,we introduce a strategy of task admission.While the lost rate exceed during several sampling periods,the strategy would forbid some non-real-time tasks.We elaborate the architecture and algorithms of the PES-ACNR,and implement the model in the RTAI.At last,some experiments illustrate the validity of the scheme.It can improve the steadiness and the ability of adapting of the CNC system.
出处
《小型微型计算机系统》
CSCD
北大核心
2010年第4期788-792,共5页
Journal of Chinese Computer Systems
基金
国家科技重大专项(2009ZX04009-013)资助
关键词
数控系统
实时操作系统
弹性实时调度算法
反馈调度
CNC system
real-time operation system
real-time elastic scheduling algorithm
feedback scheduling
