scholarly journals New Model-Based Analysis Method with Multiple Constraints for Integrated Modular Avionics Dynamic Reconfiguration Process

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 574
Author(s):  
Zeyong Jiang ◽  
Tingdi Zhao ◽  
Shihai Wang ◽  
Hongyan Ju
Keyword(s):  
Petri Net ◽  
Simulation Analysis ◽  
Dynamic Reconfiguration ◽  
Multiple Constraints ◽  
Model Based ◽  
Integrated Modular Avionics ◽  
Configuration Changes ◽  
Model Based Analysis ◽  
Architecture Analysis

With the development of integrated modular avionics (IMA), the dynamic reconfiguration of IMA not only provides great advantages in resource utilization and aircraft configuration, but also acts as a valid means for resource failure management. It is vital to ensure the correction of the IMA dynamic reconfiguration process. The analysis of the dynamic reconfiguration process is a significant task. The Architecture Analysis & Design Language (AADL) is widely used in complicated real-time embedded systems. The language can describe the system configuration and the execution behaviors, such as configuration changes. Petri net is a widely used tool to conduct simulation analysis in many aspects. In this study, a model-based analyzing method with multiple constraints for the IMA dynamic reconfiguration process was proposed. First, several design constraints on the process were investigated. Second, the dynamic reconfiguration process was modeled based on the AADL. Then, a set of rules for the transition of the model from AADL to Petri net was generated, and the multi-constraints proposed were incorporated into Petri net for analysis. Finally, a simulation multi-constraint analysis with Petri net for the process of IMA dynamic reconfiguration was conducted. Finally, a case study was employed to demonstrate this method. This method is advantageous to the validity of IMA dynamic reconfiguration at the beginning of the system design.

Model based analysis of the EU power system based on RES — A case study for Greece and Germany

2015 ◽  
Author(s):  
Pantelis Capros ◽  
Marilena Zampara ◽  
Nikos Tasios ◽  
Dimitris Papadopoulos ◽  
Christoph Kost ◽  
...  
Keyword(s):  
Power System ◽  
Model Based ◽  
The Eu ◽  
Model Based Analysis

Model-Based Analysis of Friction-Induced Sub-Synchronous Whirl for a Rotor Contacting With Clearance Bearings Under Axial Load

2015 ◽  
Author(s):  
Matthew O. T. Cole ◽  
Lawrence Hawkins
Keyword(s):  
Axial Load ◽  
Coulomb Friction ◽  
Friction Forces ◽  
Root Finding ◽  
Model Based ◽  
Simple Physical Interpretation ◽  
Level Of Agreement ◽  
Model Based Analysis

For rotors supported by active magnetic bearings (AMBs), clearance bearings are commonly used to provide backup support under loss of AMB functionality. Test data from real machines shows that rotor vibration during touchdown on backup bearings may involve steady forward whirling at a sub-synchronous frequency. This excitation is believed to be due to friction forces transmitted between the rotor and a bearing end-face under axial load. This paper proposes a new analytical approach to model and predict such friction-driven forward whirl behaviors. A set of constraint equations are derived that relate a circular whirl motion of arbitrary orbital speed to the frequency response functions of the rotor-housing structure. This model is coupled with an evaluation of Coulomb friction associated with slip between the rotor and the supporting end-face of a thrust bearing. The resulting equations can be used to compute a set of possible whirl motions via a root-finding procedure. A case study is undertaken for a 140 kW energy storage flywheel. Model-based predictions are compared with measured data from spin-down tests and show a good level of agreement. The study confirms the role of friction-related forces in driving forward-whirl response behaviors. It also highlights the key role of housing and machine support characteristics in response behavior. This influence is shown to be complex and not open to simple physical interpretation. Therefore, the proposed analytical method is seen as a useful tool to investigate this influence while avoiding the need for time consuming numerical simulations.

scholarly journals Model-based analysis and synthesis of tumor growth under angiogenic inhibition: a case study*

2011 ◽  
Vol 44 (1) ◽  
pp. 3753-3758 ◽  
Author(s):  
Dániel A. Drexler ◽  
Levente Kovács ◽  
Johanna Sápi ◽  
István Harmati ◽  
Zoltán Benyó
Keyword(s):  
Tumor Growth ◽  
Model Based ◽  
Analysis And Synthesis ◽  
Model Based Analysis

Model-Based Analysis of Friction-Induced Subsynchronous Whirl for a Rotor Contacting With Clearance Bearings Under Axial Load

2016 ◽  
Vol 138 (7) ◽  
Author(s):  
Matthew O. T. Cole ◽  
Lawrence Hawkins
Keyword(s):  
Axial Load ◽  
Coulomb Friction ◽  
Friction Forces ◽  
Root Finding ◽  
Model Based ◽  
Simple Physical Interpretation ◽  
Level Of Agreement ◽  
Model Based Analysis

For rotors supported by active magnetic bearings (AMBs), clearance bearings are commonly used to provide backup support under loss of AMB functionality. Test data from real machines shows that vibration during touchdown on backup bearings may involve steady forward whirling of the rotor with a subsynchronous frequency. This excitation is believed to be due to friction forces transmitted between the rotor and a bearing end-face under axial load. This paper proposes a new analytical approach to model and predict such friction-driven forward whirl behaviors. A set of constraint equations are derived that relate a circular whirl motion of arbitrary orbital speed to the frequency response functions for the rotor-housing structure. This model is coupled with an evaluation of Coulomb friction associated with slip between the rotor and the supporting end-face of a thrust bearing. The resulting equations can be used to compute a set of possible whirl motions via a root-finding procedure. A case study is undertaken for a 140 kW energy storage flywheel. Model-based predictions are compared with measured data from spin-down tests and show a good level of agreement. The study confirms the role of friction-related forces in driving forward-whirl response behaviors. It also highlights the key role of housing and machine support characteristics in response behavior. This influence is shown to be complex and not open to simple physical interpretation. Therefore, the proposed analytical method is seen as a useful tool to investigate this influence while avoiding the need for time consuming numerical simulations.

scholarly journals Method Based on SEFT-to-Petri for Safety Analysis of Software

2018 ◽  
Vol 179 ◽  
pp. 03030
Author(s):  
Xu Sai-sai ◽  
Chen Jing ◽  
Sun Yu-ning ◽  
Gao Xin-rui ◽  
Wang Bo-han ◽  
...  
Keyword(s):  
Systems Engineering ◽  
Petri Net ◽  
Functional Model ◽  
Logic Gates ◽  
Safety Analysis ◽  
State Machine ◽  
System Software ◽  
Model Based ◽  
Model Based Systems Engineering

System safety is a vital non-functional requirement whose satisfaction is essential for system software. However, modern aerospace system software is more and more complicated, which results in a high complexity of analyzing system faults. With the increased acceptance of Model-based Systems Engineering as a new method for systems engineering, Model-based Safety Analysis is also proposed to formalize the task of safety analysis and automate the safety calculations. Our work is grounded on State/Event Fault Tree to analyze system faults and build functional model. Firstly, we can translate SEFT to state machine based on SysML with fault syntactic messages and match elements together with translating logic gates; after which, transforming state machine into Petri Net model by means of rigorous semantic relations to extract preliminary analytical model is deduced theoretically in this paper; finally, we can derive analyses of causes and results of faults from Petri Net model by adopting a set of mathematical and statistical analysis. Practically, we have also validated our work by a case study of an aeronautic control system to support this paper.

Research on VaR-Model-Based Analysis of Construction Cost Risks

2014 ◽  
Vol 584-586 ◽  
pp. 2466-2475
Author(s):  
Dong Bing Huang ◽  
Qi Jun Li ◽  
Li Juan Shen
Keyword(s):  
Analytical Model ◽  
Construction Cost ◽  
Var Model ◽  
Key Factors ◽  
Accurate Calculation ◽  
Model Based ◽  
Set Up ◽  
The Cost ◽  
Model Based Analysis

Construction cost risk management is an essential part of construction cost management,especially in the context of the ‘triple overrun’ that has been rampant across China over the last few years,i.e. the cost overrunning the budget,the budget overrunning the budgetary estimate, and the budgetary estimate overrunning the initial estimate. Since traditional methods of calculating construction reserve funds fail to serve the purpose of curbing the ‘triple overrun’,we deem it necessary to establish a quantitative, rational, and accurate calculation and analytical model to measure basic reserve funds. This paper aims to provide an analytical model based on the VaR technique, where parameters are determined by VaR’s three key factors, and a standard VaR process of analyzing basic reserve funds is set up. The model proves to be effective in our case study when basic reserve funds predicted by the model well match the actual ones,which is shown clearly by the Q-Q plot curves and CDF curves.

Sign in / Sign up

Export Citation Format

Share Document