Recently the integrated modular avionics （IMA） architecture which introduces the concept of resource partitioning becomes popular as an alternative to the traditional federated architecture. A novel hierarchical app...Recently the integrated modular avionics （IMA） architecture which introduces the concept of resource partitioning becomes popular as an alternative to the traditional federated architecture. A novel hierarchical approach is proposed to solve the resource allocation problem for IMA systems in distributed environments. Firstly, the worst case response time of tasks with arbitrary deadlines is analyzed for the two-level scheduler. Then, the hierarchical resource allocation approach is presented in two levels. At the platform level, a task assignment algorithm based on genetic simulated annealing （GSA） is proposed to assign a set of pre-defined tasks to different processing nodes in the form of task groups, so that resources can be allocated as partitions and mapped to task groups. While yielding to all the resource con- straints, the algorithm tries to find an optimal task assignment with minimized communication costs and balanced work load. At the node level, partition parameters are optimized, so that the computational resource can be allocated further. An example is shown to illustrate the hierarchal resource allocation approach and manifest the validity. Simulation results comparing the performance of the proposed GSA with that of traditional genetic algorithms are presented in the context of task assignment in IMA systems.展开更多
Health management permits the reliability of a system and plays a increasingly important role for achieving efficient system-level maintenance.It has been used for remaining useful life（RUL） prognostics of electroni...Health management permits the reliability of a system and plays a increasingly important role for achieving efficient system-level maintenance.It has been used for remaining useful life（RUL） prognostics of electronics-rich system including avionics.Prognostics and health management（PHM） have become highly desirable to provide avionics with system level health management.This paper presents a health management and fusion prognostic model for avionics system,combining three baseline prognostic approaches that are model-based,data-driven and knowledge-based approaches,and integrates merits as well as eliminates some limitations of each single approach to achieve fusion prognostics and improved prognostic performance of RUL estimation.A fusion model built upon an optimal linear combination forecast model is then utilized to fuse single prognostic algorithm representing the three baseline approaches correspondingly,and the presented case study shows that the fusion prognostics can provide RUL estimation more accurate and more robust than either algorithm alone.展开更多
In parametric cost estimating, objections to using statistical Cost Estimating Relationships （CERs） and parametric models include problems of low statistical significance due to limited data points, biases in the un...In parametric cost estimating, objections to using statistical Cost Estimating Relationships （CERs） and parametric models include problems of low statistical significance due to limited data points, biases in the underlying data, and lack of robustness. Soft Computing （SC） technologies are used for building intelligent cost models. The SC models are systemically evaluated based on their training and prediction of the historical cost data of airborne avionics systems. Results indicating the strengths and weakness of each model are presented. In general, the intelligent cost models have higher prediction precision, better data adaptability, and stronger self-learning capability than the regression CERs.展开更多
Aviation electronics (avionics) are sophisticated and distributed systems aboard an airplane. The complexity of these systems is constantly growing as an increasing amount of functionalities is realized in software. T...Aviation electronics (avionics) are sophisticated and distributed systems aboard an airplane. The complexity of these systems is constantly growing as an increasing amount of functionalities is realized in software. Thanks to the performance increase, a hardware unit must no longer be dedicated to a single system function. Multicore processors for example facilitate this trend as they are offering an increased system performance in a small power envelope. In avionics, several system functions could now be integrated on a single hardware unit, if all safety requirements are still satisfied. This approach allows for further optimizations of the system architecture and substantial reductions of the space, weight and power (SWaP) footprint, and thus increases the transportation capacity. However, the complexity found in current safety-critical systems requires an automated software deployment process in order to tap this potential for further SWaP reductions. This article used a realistic flight control system as an example to present a new model-based methodology to automate the software deployment process. This methodology is based on the correctness-by-construction principle and is implemented as part of a systems engineering toolset. Furthermore, metrics and optimization criteria are presented which further help in the automatic assessment and refinement of a generated deployment. A discussion regarding a tighter integration of this approach in the entire avionics systems engineering workflow concludes this article.展开更多
面向民用航空维修训练领域,提出一种模块化、层次化的故障行为建模仿真方法。针对航电系统结构复杂、故障种类繁多、信息流难以控制等特点,依据飞机相关手册资料,采用离散事件系统DEVS(Discrete Event System)描述系统的结构和行为,采...面向民用航空维修训练领域,提出一种模块化、层次化的故障行为建模仿真方法。针对航电系统结构复杂、故障种类繁多、信息流难以控制等特点,依据飞机相关手册资料,采用离散事件系统DEVS(Discrete Event System)描述系统的结构和行为,采用电气线性网络ELN(Electrical Linear Networks)计算模型描述系统的电气特性,在System C/System C AMS仿真环境下对系统进行故障仿真。经验证该方法能真实反映正常和故障情况下航电系统电气特性和功能行为,基本满足维修训练仿真要求。展开更多
针对智能航电系统在非线性耦合运行场景下产生的预期功能安全(safety of the intended functionality,SOTIF)问题,提出一种将系统理论过程分析(systematic theory process analysis,STPA)与决策试验与评价实验法(decision-making trial ...针对智能航电系统在非线性耦合运行场景下产生的预期功能安全(safety of the intended functionality,SOTIF)问题,提出一种将系统理论过程分析(systematic theory process analysis,STPA)与决策试验与评价实验法(decision-making trial and evaluation laboratory,DEMATEL)相结合的致因分析框架。首先,在定义系统级危险的基础上构建安全控制结构,识别其不安全控制行为并提取与智能化缺陷相关的STPA致因要素。接下来,引入毕达哥拉斯模糊加权平均算子和闵可夫斯基距离对传统DEMATEL方法进行优化,专家根据控制反馈回路对致因要素进行评价并计算其中心度与原因度。最后,分析STPA致因要素与SOTIF致因属性之间的映射关系,给出关键致因要素的风险减缓措施。以单一飞行员驾驶(single-pilot operation,SPO)模式下的虚拟驾驶员助理系统为例说明了所提方法的可行性与有效性。研究结果表明,改进的STPA-DEMATEL方法可以有效识别关键致因要素,且能够克服专家评价的模糊性与不确定性,为智能航电系统的安全性设计提供了参考依据。展开更多
基金supported by the National Natural Science Foundation of China (60879024)
文摘Recently the integrated modular avionics （IMA） architecture which introduces the concept of resource partitioning becomes popular as an alternative to the traditional federated architecture. A novel hierarchical approach is proposed to solve the resource allocation problem for IMA systems in distributed environments. Firstly, the worst case response time of tasks with arbitrary deadlines is analyzed for the two-level scheduler. Then, the hierarchical resource allocation approach is presented in two levels. At the platform level, a task assignment algorithm based on genetic simulated annealing （GSA） is proposed to assign a set of pre-defined tasks to different processing nodes in the form of task groups, so that resources can be allocated as partitions and mapped to task groups. While yielding to all the resource con- straints, the algorithm tries to find an optimal task assignment with minimized communication costs and balanced work load. At the node level, partition parameters are optimized, so that the computational resource can be allocated further. An example is shown to illustrate the hierarchal resource allocation approach and manifest the validity. Simulation results comparing the performance of the proposed GSA with that of traditional genetic algorithms are presented in the context of task assignment in IMA systems.
文摘Health management permits the reliability of a system and plays a increasingly important role for achieving efficient system-level maintenance.It has been used for remaining useful life（RUL） prognostics of electronics-rich system including avionics.Prognostics and health management（PHM） have become highly desirable to provide avionics with system level health management.This paper presents a health management and fusion prognostic model for avionics system,combining three baseline prognostic approaches that are model-based,data-driven and knowledge-based approaches,and integrates merits as well as eliminates some limitations of each single approach to achieve fusion prognostics and improved prognostic performance of RUL estimation.A fusion model built upon an optimal linear combination forecast model is then utilized to fuse single prognostic algorithm representing the three baseline approaches correspondingly,and the presented case study shows that the fusion prognostics can provide RUL estimation more accurate and more robust than either algorithm alone.
文摘In parametric cost estimating, objections to using statistical Cost Estimating Relationships （CERs） and parametric models include problems of low statistical significance due to limited data points, biases in the underlying data, and lack of robustness. Soft Computing （SC） technologies are used for building intelligent cost models. The SC models are systemically evaluated based on their training and prediction of the historical cost data of airborne avionics systems. Results indicating the strengths and weakness of each model are presented. In general, the intelligent cost models have higher prediction precision, better data adaptability, and stronger self-learning capability than the regression CERs.
文摘Aviation electronics (avionics) are sophisticated and distributed systems aboard an airplane. The complexity of these systems is constantly growing as an increasing amount of functionalities is realized in software. Thanks to the performance increase, a hardware unit must no longer be dedicated to a single system function. Multicore processors for example facilitate this trend as they are offering an increased system performance in a small power envelope. In avionics, several system functions could now be integrated on a single hardware unit, if all safety requirements are still satisfied. This approach allows for further optimizations of the system architecture and substantial reductions of the space, weight and power (SWaP) footprint, and thus increases the transportation capacity. However, the complexity found in current safety-critical systems requires an automated software deployment process in order to tap this potential for further SWaP reductions. This article used a realistic flight control system as an example to present a new model-based methodology to automate the software deployment process. This methodology is based on the correctness-by-construction principle and is implemented as part of a systems engineering toolset. Furthermore, metrics and optimization criteria are presented which further help in the automatic assessment and refinement of a generated deployment. A discussion regarding a tighter integration of this approach in the entire avionics systems engineering workflow concludes this article.
文摘综合化航空电子系统(Integrated Modular Avionics, IMA)是一类典型的安全关键系统,具有分布式、异构、计算资源和物理资源强耦合等特征。随着IMA系统趋于复杂化和智能化,系统的功能越来越多地采用软件来实现,如何对这类复杂软件进行建模并自动生成代码成为一个重要挑战。文中提出了一种基于AADL(Architecture Analysis and Design Language)的综合化航空电子系统代码生成方法。首先,提出HMC4ARINC653(Heterogeneous Model Container for ARINC653)属性集扩展,使其具备描述IMA软件架构、异构功能行为和非功能属性的能力;其次,提出IMA模型到C代码及ARINC653系统配置文件的映射规则,并遵守MISRA C安全编码规范,生成的代码能够在ARINC653操作系统上部署并仿真执行;最后,设计并实现了相应的原型工具,以ARINC653操作系统和工业界实际案例,验证了所提方法和工具的有效性。
文摘面向民用航空维修训练领域,提出一种模块化、层次化的故障行为建模仿真方法。针对航电系统结构复杂、故障种类繁多、信息流难以控制等特点,依据飞机相关手册资料,采用离散事件系统DEVS(Discrete Event System)描述系统的结构和行为,采用电气线性网络ELN(Electrical Linear Networks)计算模型描述系统的电气特性,在System C/System C AMS仿真环境下对系统进行故障仿真。经验证该方法能真实反映正常和故障情况下航电系统电气特性和功能行为,基本满足维修训练仿真要求。
文摘针对智能航电系统在非线性耦合运行场景下产生的预期功能安全(safety of the intended functionality,SOTIF)问题,提出一种将系统理论过程分析(systematic theory process analysis,STPA)与决策试验与评价实验法(decision-making trial and evaluation laboratory,DEMATEL)相结合的致因分析框架。首先,在定义系统级危险的基础上构建安全控制结构,识别其不安全控制行为并提取与智能化缺陷相关的STPA致因要素。接下来,引入毕达哥拉斯模糊加权平均算子和闵可夫斯基距离对传统DEMATEL方法进行优化,专家根据控制反馈回路对致因要素进行评价并计算其中心度与原因度。最后,分析STPA致因要素与SOTIF致因属性之间的映射关系,给出关键致因要素的风险减缓措施。以单一飞行员驾驶(single-pilot operation,SPO)模式下的虚拟驾驶员助理系统为例说明了所提方法的可行性与有效性。研究结果表明,改进的STPA-DEMATEL方法可以有效识别关键致因要素,且能够克服专家评价的模糊性与不确定性,为智能航电系统的安全性设计提供了参考依据。
