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Xu Y.-T.,Beijing Institute of Technology | Yin Y.-F.,Beihang University | Sun J.,Ordnance Science and Research Academy of China | Zhang C.,Beihang University | Liu B.,Beihang University
Binggong Xuebao/Acta Armamentarii | Year: 2015

Software reliability is one of the most important quality indices in software quality evaluation. With the development of software engineering and component reusing, the reliability analysis based on software architecture has become a researching hotspot. This paper puts a research on existed architecture-based reliability estimation models at first, then proposes existing architecture based reliability estimation types and typical models, putting forward the shortage of these models as well. As Petri net has a well expansibility and descriptive power of concurrency and asynchronism, this paper focuses on the research of Petri net model, divides transition into time transition and instant transition, and adds time-related reliability-time-delay reliability and temporal reliability, by this means establish the software architecture modeling. The reachable state transition matrix is set up and the system reliability estimation is made by studing the relationship between component state and system reachable state. At last, the method is used in a avionics embedded software for architecture modeling, reliability estimation and error analysis, proving the effectiveness and accuracy of this method. ©, 2015, China Ordnance Society. All right reserved. Source


Gao X.-X.,Nanjing University of Science and Technology | Su Z.-Z.,Ordnance Science and Research Academy of China | Sun H.-G.,Institute of Armament Technology | Hou B.-L.,Nanjing University of Science and Technology
Binggong Xuebao/Acta Armamentarii | Year: 2014

An optimization design method is proposed to indirectly improve the reliability of positioning precision for shell transfer arm in ammunition automatic loading system with uncertain parameters. The main uncertain factors that influence the positioning performance are analyzed. Space is transformed, and Latin hypercube sampling is applied for the uncertain variables. The error weights are calculated according to the distances from sampling points to the mean point in the transformed space. An electromechanical model is established with MATLAB/Simulink, and the simulations are run for every sampling point to get the positioning errors. The weighted sum of these errors is calculated as a performance index. This performance index is optimized using particle swarm algorithm. This method has remarkable optimization effect and good computational efficiency. Source


Wen Q.-Q.,Beijing Institute of Technology | Liu D.-W.,Ordnance Science and Research Academy of China | Xia Q.-L.,Beijing Institute of Technology | Li R.,Beijing Institute of Technology
Binggong Xuebao/Acta Armamentarii | Year: 2014

An extended optimal guidance law with terminal miss distance and impact angle constrains is derived. The guidance law is obtained as the solution of a linear quadratic optimal control problem with the goal function weighted by a power of the time-to-go. Based on the analytical expression for the change of guidance command with time and the adjoint system analysis method, the command characteristics and dimensionless miss distance of guidance law are analyzed. The result shows that the acceleration command of guidance law can be converged into zero in the final time of guidance, which may create a good situation for terminal angle of attack control. A design principle for selection of guidance law gain is discussed. Finally, according to the requirements of engineering application, the methods on calculating the guidance initial condition and maximal required acceleration are given. The effectiveness and practicality of the guidance law are demonstrated through simulation. Source


Zhang X.-P.,China North Vehicle Research Institute | Wang Y.-L.,Ordnance Science and Research Academy of China | Du M.-G.,China North Vehicle Research Institute | Yang Y.,China North Vehicle Research Institute
Binggong Xuebao/Acta Armamentarii | Year: 2016

The life and reliability of integrated transmission device may be significantly affected by the vibration, harshness and quality of the device. The relationship between the internal excitation and vibration of the device is one of the important research works. An experimental scheme is presented to obtain the relationship between the internal excitation and vibrations of an integrated transmission device. A coupling signal analysis method is also proposed to investigate the signals from the multiple measurement points and experimental conditions. The relationship between the internal excitation and vibration of the device is obtained based on the proposed experimental method, which can provide some guidance for the structure optimization of the device. The results show that the experimental analysis method can be used to not only determine the vibration source location of the integrated transmission device, but also find the dominant frequency which should be controled, which can provide some guidance for the structure optimization of the device. © 2016, Editorial Board of Acta Armamentarii. All right reserved. Source


Zhang D.-C.,Beijing Institute of Technology | Sun J.,Ordnance Science and Research Academy of China | Wen Q.-Q.,Beijing Institute of Technology | Xia Q.-L.,Beijing Institute of Technology
Beijing Ligong Daxue Xuebao/Transaction of Beijing Institute of Technology | Year: 2016

A guidance method was proposed, considering seeker field of view constraints and impact angle constraint, for the reason that the seeker look angle of air to ground weapon may overstep the field of view and lose the target when it follows the optimal trajectory shaping guidance law to achieve large impact angle. An analytic expression of seeker look angle was deduced based on the assumption of linearization model and small angle. The factors that influence seeker look angle and the range of maximum seeker look angle were analyzed. On this basis, the guidance method satisfied the seeker field of view constraints through changing the initial line of sight angle or relaxed impact angle constraints was put forward for different air to ground weapons. The select principle of initial line of sight value and the maximum impact angle calculation method were also presented. Numerical simulations verified the effectiveness of the seeker look angle theoretical expressions and the proposed guidance method. © 2016, Beijing Institute of Technology. All right reserved. Source

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