民机驾驶舱布局流程设计及应用

为减少民机驾驶舱设计迭代次数,提高设计质量和效率,提出了一种民机驾驶舱布局的设计流程。结合适航要求和人机工效分析方法,对飞行员眼位、人体尺寸、内部视界和外部视界、飞行员坐姿、座椅和脚蹬调节行程、中控台尺寸及其它关键部件位置进行了分析和研究。最后,应用提出的民机驾驶舱布局流程进行了公务机驾驶舱布局设计。结果表明,设计的民机驾驶舱布局流程能够快速实现预期设计目标,提高了设计效率,对民机驾驶舱设计具有指导意义。     

基于字典序整数编号的大型空间智能桁架结构主动杆位置优化

智能计算方法在大型空间智能桁架结构的主动杆优化配置问题中有着广泛的应用。为有效避免传统遗传算法编码方式在算法实现过程中容易出现无效染色体的问题,本文基于字典序整数编号的遗传算法,给出了一个由整数编号还原到对应组合的快速还原算法。利用此方法对空间T型桁架结构的主动杆位置优化进行仿真并与传统编码方法结果进行比较,验证了本文方法的有效性和优越性。     

自动铺丝平行等距轨迹规划算法实现

针对复合材料自动铺丝技术轨迹规划问题,提出了一种新的基于测地线的平行等距轨迹规划算法.该算法首先将已知的第一条轨迹线在曲面上等弧长离散得到若干数据点,然后在数据点处曲线切矢和曲面法矢的向量积方向上利用测地线的短程性获得下一条铺放轨迹上数据点,并利用B样条曲线拟和数据点生成铺放轨迹,最后使轨迹线铺满模具表面.算法中测地线利用微分方程组数值求解得到,以曲面曲线弧长为自变量,可实现等距线求解的自适应步长调整和较高的精度.经实际算例验证,该算法简单实用,精度能够满足铺丝技术工艺要求.     

翻修贴片设备在ICCD光锥耦合中的应用

为了提高光锥耦合ICCD成像系统的成品率和成像质量,提出了一种将通用BGA翻修系统中的高精度贴片设备ERSA PL550A用于光锥和CCD耦合工艺的方法。利用光锥或光纤面板与CCD的耦合实例描述了这种技术方案的系统构成、操作流程和耦合精度,证明了它在简化耦合工艺、降低操作难度、控制耦合操作的重复性和提高生产效率方面具有良好的性能。对CCD玻璃窗的开启方法和光锥形状尺寸的二次修改也进行了简要说明。     

Actuator placement based on reachable set optimization for expected disturbance

This paper examines the role of the control objective and the control time in determining fuel-optimal actuator placement for structural control. A general theory is developed that can be easily extended to include alternative performance metrics such as energy and timeoptimal control. The performance metric defines a convex admissible control set which leads to a max-min optimization problem expressing optimal location as a function of initial conditions and control time. A solution procedure based on a nested genetic algorithm is presented and applied to an example problem. Results indicate that the optimal placement varies widely as a function of both control time and disturbance location. An approximate fitness function is presented to alleviate the computational burden associated with finding exact solutions. This function is shown to accurately predict the optimal actuator locations for a 6th-order system, and is further demonstrated on a 12th-order system.This work was supported by the US Department of Energy at Sandia National Laboratories under Contract DE-AC04-76DP00789.     

Guided Local Search for Final Placement in VLSI Design

The design of a VLSI circuit consists of two main parts: First, the logical functionality of the circuit is described, and then the physical layout of the modules and connections is settled. In the latter process one wishes to place the modules such that the necessary wiring becomes as small as possible in order to minimize area usage and delays on signal paths. The placement problem is the subproblem of the layout problem which considers the geometric locations of the modules. A new heuristic is presented for the general cell placement problem where the objective is to minimize total bounding box netlength. The heuristic is based on the Guided Local Search (GLS) metaheuristic. GLS modifies the objective function in a constructive way to escape local minima. Previous attempts to use local search on final (or detailed) placement problems have often failed as the neighbourhood quickly becomes too excessive for large circuits. Nevertheless, by combining GLS with Fast Local Search it is possible to focus the search on appropriate sub-neighbourhoods, thus reducing the time complexity considerably. Comprehensive computational experiments with the developed algorithm are reported on a broad range of industrial circuits. The experiments demonstrate that the developed algorithm is able to improve the estimated routing length of large-sized layouts with as much as 20 percent when compared to existing algorithms.     

Optimal capacitor placement to minimizing cost and power loss in Tehran metro power distribution system using ETAP (A case study)

Most loads in the power distribution system of Tehran Metro (Subway) are inductive and lead to poor power factor (PF) especially in Lighting and Power Substation. One of the methods of PF correction is adding or producing the capacitive components within the circuit to eliminate the effect of inductive loads. Optimal capacitor placement (OCP), with the objects of power system voltage profile improvement, PF correction, loss reduction, and line reactive power decrease are of particular importance in power system control and planning. These objects depend on how the capacitive components are installation and to achieve them, since the capacitor placement is nonlinear problem and has some equally and inequality constraint. This article investigates OCP in the actual power distribution grid of Tehran Metro (Line 2) in the presence of nonlinear loads. The placement problem is solved using Genetic Algorithms as implemented in the Electrical Transient Analyser Program software. Results (capacity release, total generation, loading, demand, power losses and number of capacitor banks, costs and annual benefits) are obtained and analysed. This study and simulation shows that by OCP can calculate reduce annual losses and release capacity of equipment in power distribution grid of Tehran Metro such as cables and transformers from reactive power and that will maximize profits. © 2016 Wiley Periodicals, Inc. Complexity 21: 483–493, 2016     

Exact and heuristic methods for placing ships in locks

The ship placement problem constitutes a daily challenge for planners in tide river harbours. In essence, it entails positioning a set of ships into as few lock chambers as possible while satisfying a number of general and specific placement constraints. These constraints make the ship placement problem different from traditional 2D bin packing. A mathematical formulation for the problem is presented. In addition, a decomposition model is developed which allows for computing optimal solutions in a reasonable time. A multi-order best fit heuristic for the ship placement problem is introduced, and its performance is compared with that of the left-right-left-back heuristic. Experiments on simulated and real-life instances show that the multi-order best fit heuristic beats the other heuristics by a landslide, while maintaining comparable calculation times. Finally, the new heuristic’s optimality gap is small, while it clearly outperforms the exact approach with respect to calculation time.     

Partial pole placement with time delay in structures using the receptance and the system matrices

Datta et al. solved the partial pole placement problem for the symmetric definite quadratic eigenvalue problem where part of the spectrum is relocated to predetermined locations and the rest of the spectrum remains unchanged. In this paper, the problem is solved by a hybrid combination of this result and the method of receptances. This allows for the partial assignment of desired poles with no spillover when there is time delay between the measured or estimated state and actuation of the control.