数控装置硬件平台功能安全研究与实现

发布时间：2018-05-29 17:41

本文选题：功能安全 + 失效模式　；参考：《中国科学院研究生院（沈阳计算技术研究所）》2015年硕士论文

【摘要】：本课题以“高档数控机床与基础制造装备”国家科技重大专项中“数控系统功能安全技术研究”子课题为依托,研究了数控装置硬件平台功能安全等级的定量评估方法,并对其硬件平台实施了“评估-改进-再评估”的迭代设计。论文主要包含以下几项研究内容:失效分布确定、故障模式分析、安全评估建模以及电路优化设计。确定失效分布类型时,采用现场反馈数据绘制的装置失效概率密度散点图,与常见失效分布曲线进行拟合,选出拟合程度最佳的分布曲线,即装置所服从的失效分布类型;此后进行故障模式分析,提出了基于数理统计的失效数据分析法,从而解决传统故障影响分析时数据源难以获取的问题;在上述工作的基础上,选用两种适用于指数失效的概率计算模型:基于故障树的可靠性框图法和离散马尔科夫模型对数控装置进行安全评估建模,确定数控装置所能达到的安全完整性等级;最后基于安全评估结果,从影响系统失效的概率分布着手,对装置硬件结构在采购、降额、诊断以及冗余四个方面进行改进设计,以提升系统的安全性能。验证改进后数控装置硬件安全完整性等级达到预期目标SIL2,实现改进目的。通过完成以上几部分工作,课题基本实现了国产数控装置硬件平台功能安全评估体系的构建,在实际工程应用上具有很高的操作性和可行性,为进一步实现国产高安全性能的数控产品研制工作奠定了基础。
[Abstract]:Based on the subtopic of "Research on functional Safety Technology of CNC system" in "High-grade CNC Machine tool and basic Manufacturing equipment", the quantitative evaluation method of functional safety grade of hardware platform of CNC device is studied. And implement the iterative design of the hardware platform "Evaluation-improvement-re-evaluation". This paper mainly includes the following research contents: failure distribution determination, fault mode analysis, safety evaluation modeling and circuit optimization design. When the failure distribution type is determined, the scattered plot of the device failure probability density drawn by the field feedback data is used to fit the common failure distribution curve, and the distribution curve with the best fitting degree is selected, that is, the failure distribution type followed by the device; After that, fault mode analysis is carried out, and failure data analysis method based on mathematical statistics is put forward to solve the problem that data sources are difficult to obtain in traditional fault impact analysis. Two probabilistic models suitable for exponential failure are selected: reliability block diagram method based on fault tree and discrete Markov model are used to model the safety evaluation of numerical control device to determine the level of safety integrity that can be achieved by numerical control device; Finally, based on the result of safety assessment, the paper designs the hardware structure of the device in four aspects, such as purchasing, reducing, diagnosing and redundancy, from the probability distribution that affects the failure of the system, so as to improve the safety performance of the system. Verify that the improved NC device hardware security integrity level to achieve the desired goal sill 2 to achieve the purpose of improvement. By completing the above several parts of the work, the subject has basically realized the construction of the function safety evaluation system of the hardware platform of the domestic numerical control device, which has high operability and feasibility in the practical engineering application. It lays a foundation for the development of CNC products with high safety performance.
【学位授予单位】：中国科学院研究生院（沈阳计算技术研究所）
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG659

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